Abstracts| Volume 6, ISSUE 6, P380-583, November 01, 2021

# ISAKOS 2021 Global Congress

Open Access

## Abstracts

### 19003 Timing of return to hitting following ulnar collateral ligament reconstruction in professional baseball players

Brandon Erickson
Brandon Erickson
Peter Chalmers
John D’Angelo
Kevin Ma
Scott Sheridan
Mark Steven Schickendantz
Anthony A Romeo
USA
Summary
It take hitters roughly 150 days to begin a hitting program following ulnar collateral ligament reconstruction but over 300 days before they can return to sport.
Data
Background
Ulnar collateral ligament reconstruction (UCLR) is a common procedure in professional baseball position players. Timing of return to hitting following UCLR is unknown.
Purpose
Determine the time to return to batting milestones after UCLR as well as the effect of UCLR upon batting performance in professional baseball players.
Hypothesis
Position players would return to batting in an in-season game prior to fielding in an in-season game, and hitting performance would remain unchanged following UCLR
Methods
All professional position players who underwent UCLR between 2010–2018 were included. Time to batting milestones following UCLR was analyzed. Batting performance before and after UCLR was compared and analyzed.
Results
Overall, 141 UCLRs (96% performed on the dominant arm) in 137 position players were included (86% minor leaguers). Four players underwent revision, all within one year of the primary UCLR. With regard to position, catchers and shortstops were over-represented. With regard to batting side, 57% batted from the right and 12% batted as switch-hitters, and thus 76% of surgeries were on the lead arm. While 91% of players were able to return to any throwing at all, there was a progressive gradual decline during the rehabilitation progress such that 77% were able to return to hitting in a real game and 75% were able to return to fielding in a real game. The first dry swing occurred at 150±49 days after surgery, first batting practice occurred at 195±58 days after surgery, and first hitting in a real game occurred at 323±92 days after surgery. However, players generally saw a decrease in their utilization, with fewer at bats (p<0.001) translating into fewer hits (p<0.001) and runs (p<0.001).
Conclusion
Professional position players begin swinging at 150 days following UCLR while they do not hit batting practice until 195 days and do not hit in a real game until 323 days following UCLR. Players saw a decrease in hitting utilization following UCLR.
Shoulder
Preventative Sports Medicine
Tears
Orthopaedic Sports Medicine

### 19011 Is arthroscopy an adequate therapy for all borderline dysplastic hips? Correlation between radiologic findings and clinical outcomes

Alexander Zimmerer
Alexander Zimmerer
Wolfgang Miehlke
Christian Sobau
Germany
Summary
Evaluating and grading the hip morphology of patients with borderline dysplasia is crucial since the clinical outcomes differ among the various clusters. Hip arthroscopy produces excellent results for stable anterolateral and lateral deficiency borderline hips.
Data
Purpose
The aim of this study was to analyze a cohort with borderline dysplastic hips who were treated by hip arthroscopy to classify specify hip morphology subtypes according to radiographic abnormalities and to report the short-term clinical outcomes of these different clusters.
Methods
Patients with a lateral center-edge angle (LCEA) between 18° and 25° who underwent hip arthroscopy between January 2015 and December 2016 were examined. According to the radiographic parameters, including the LCEA, Femoro-Epiphyseal Acetabular Roof (FEAR) index, anterior and posterior wall index (AWI and PWI), Tönnis angle, alpha angle and femoral neck-shaft angle, a hierarchical cluster analysis was performed to identify the hip morphology subtypes. In addition, the International Hip Outcome Tool-12 (iHOT-12) and a pain visual analog scale (VAS) were applied preoperatively and at follow-up and compared among the different clusters.
Results
A total of 40 patients with an LCEA between 18° and 25° who underwent hip arthroscopy between January 2015 and December 2016 were identified. Thirty-six patients were available for evaluation at a mean follow-up of 43.8 months. In total, 4 different sex-independent clusters with different patterns of hip morphology were identified: cluster 1: the unstable anterolateral deficiency cluster; cluster 2: the stable anterolateral deficiency cluster; cluster 3: the stable lateral deficiency cluster; and cluster 4: the stable posterolateral deficiency cluster. At follow-up, all groups had significantly improved iHOT-12 (p<0.0001) and pain VAS scores (p=0.0001). Within the individual clusters, clusters 2 and 3 showed highly significant improvements, cluster 1 showed significant improvements, and cluster 4 showed no significant improvements.
Conclusion
Evaluating and grading the hip morphology of patients with borderline dysplasia is crucial since the clinical outcomes differ among the various clusters. Hip arthroscopy produces excellent results for stable anterolateral and lateral deficiency borderline hips. In contrast, borderline dysplastic hips with additional acetabular retroversion showed no improvement after arthroscopic therapy.
Hip/Groin/Thigh
Arthroscopy
Impingement
Cartilage
Cartilage Treatment
Femoroacetabular Impingement
Labrum
Osteoarthritis

### 19068 A comparative study of the effectiveness of ultrasound-guided puncture-Aspiration vs. arthroscopic treatment for rotator cuff calcific tendinopathy

Carlos Daniel Lobo-Oropeza
Carlos Daniel Lobo-Oropeza
Roger Rojas
Andrés Alex Faría
Venezuela
2SPAIN
Summary
Ultrasound-guided puncture-aspiration and arthroscopic treatment offer good results for the treatment of rotator cuff calcific tendinopathy. Both treatments bring about significant clinical and functional improvement in patients. In this study, no statistically significant differences were found in terms of improvements on the DASH scale or Constant scale at 6 and 12 months in patients treated by
Data
Calcific tendinopathy of the rotator cuff is one of the main causes of the non-traumatic painful shoulder between 40–60 years of age. It can cause acute and chronic inflammatory symptoms with disabling pain. Objectives The objective of the study was to compare the therapeutic effectiveness of ultrasound-guided puncture-aspiration versus arthroscopic treatment for rotator cuff calcific tendinopathy in patients in whom conservative treatment has failed.
Study Design & Methods
All patients treated by means of ultrasound-guided puncture-aspiration and/or arthroscopic treatment for rotator cuff calcific tendinopathy in our center from May 2017 to January 2019 were included. Demographic data, the morphology and location of the lesion, the therapeutic procedure as well as its clinical evolution were retrospectively evaluated using the Constant and DASH scales. The evaluations were carried prior to the procedures and at six months and one year after the intervention. A statistical analysis of the data was carried out using the SPSS Statistics software package.
Results
The mean age of the 32 patients who were included was 46 years and 21 (65.6%) of them were women. Ultrasound-guided puncture-aspiration was carried out on 17 patients (53.1%) and 15 patients (46.9%) were treated with resection and arthroscopic repair. In 3 cases (9.3%), both therapeutic techniques were performed due to there being no clinical improvement after performing ultrasound-guided puncture-aspiration alone. The lesion affected the dominant shoulder in 91% of the patients. The lesion was located in the supraspinatus tendon in 94% of all the cases. The score on the DASH scale and Constant scale prior to treatment in the ultrasound-guided aspiration group was 51.2 and 39.8, respectively. After the therapeutic procedure, they stood at 17.3 and 82 at 6 months and 14.3 and 87 at 12 months, respectively. The DASH scale and Constant scale scores in the arthroscopic group were 49.2 and 42.5 before treatment. After surgery, they were 26.7 and 70.5 at 6 months and 16.6 and 84.5 at 12 months. No statistically significant differences were seen in the statistical analysis relative to the Constant and DASH scales in the evaluations prior to surgery. Neither were any statistically significant differences seen at 6 and 12 months for either of the two therapeutic procedures.
Conclusions
Ultrasound-guided puncture-aspiration and arthroscopic treatment offer good results for the treatment of rotator cuff calcific tendinopathy. Both treatments bring about significant clinical and functional improvement in patients. In this study, no statistically significant differences were found in terms of improvements on the DASH scale or Constant scale at 6 and 12 months in patients treated by ultrasound-guided aspiration when compared to those treated with arthroscopic surgery.
Shoulder
Glenohumeral
Impingement
Repair/Reconstruction
Sutures/Knots/Anchors
Arthroscopy
Economic Analysis
Evidence Based Medicine
Exercise Physiology
Infraespinatus Tendon Injury
Ligaments
MRI
Rehabilition/Physical Therapy
Sprain
Subescapular Tendon Injury
Supraespinoatus Tendon Injury
Tendon
Ultrasound

### 19052 Skeletally immature patients with classic anterior cruciate ligament bone bruise patterns have a higher chance of having an intact anterior cruciate ligament than skeletally mature patients

David Lee Bernholt
Aaron Baessler
Jessica M Buchman
Dexter Witte
Tyler Brolin
Thomas Ward Throckmorton
Frederick M Azar
David Lee Bernholt
USA
Summary
This is a retrospective cohort study that demonstrates amongst that pediatric patients with an open femoral physis have a 10-fold increased likelihood of having an intact ACL despite the presence of bipolar lateral femoral condyle and posterior lateral tibial plateau bone contusions after an acute injury compared to patients with a closed femoral physis.
Data
Background
Bone contusion patterns following anterior cruciate ligament (ACL) tears have been extensively studied in adult patients. A recent study has shown pediatric patients with ACL injuries to have the same bone contusion pattern as adults and occurred at similar rates. However, the incidence of ACL tears in skeletally immature patients who have an ACL pattern of bone contusion has not be previously investigated.
Purpose
To radiographically determine the incidence of ACL tears in skeletally immature patients with the classic lateral femoral condyle (LFC) and lateral tibial plateau (LTP) bone bruise pattern that is seen in adults with ACL tears.
Methods
This retrospective cohort study was performed by performing a query for “contusion” within the MRI read for all patients between the ages of 6 and 22 years of age, with MRIs performed from 1/1/2015 to 6/30/2019. MRI images were reviewed to denote the presence of ACL, PCL, MCL, or LCL tears, meniscus tears, cartilage lesions, bone bruise pattern, and physeal status of femoral and tibial physes. MRIs were reviewed by two fellowship-trained orthopedic surgeons. The specific locations of bone contusions were recorded using zones described by the Whole-Organ Magnetic Resonance Imaging Score (WORMS) for bone contusion. The primary outcome variable was the incidence of ACL tears in patients with the presence of both central lateral femoral condyle and posterior lateral tibial plateau bone contusions. We analyzed differences in the primary outcome variable based upon physeal status using Fischer’s Exact testing.
Results
A total of 691 patients who met inclusion criteria were identified. There were 192 patients excluded (151 patellar instability, 23 history of prior ACL reconstruction, 7 with no bony contusions, 3 with fibular head contusion only, 2 with patellar fracture, 2 with tibial plateau fracture, and 2 with no viewable MRI). Of the 499 remaining patients, a total of 269 patients had the presence of both central lateral femoral condylar and posterior lateral tibial plateau bone contusions. Of these 269 patients, 259 (96.3%) had an ACL tear identified on MRI. Patients with an open femoral physis had a higher likelihood of having an intact ACL despite the presence of central LFC and posterior LTP contusions than patients with a closed femoral physis (8/74 (10.8%) vs. 2/195 (1.0%), chi-square value 14.4, p < 0.001). Patients with an intact ACL tear despite presence of central LFC and posterior LTP contusions were younger than patients with ACL tear with this contusion pattern (14.6 vs. 16.4, p = .017).
Conclusion
Patients who have an open femoral physis have a higher likelihood to have an intact ACL despite the presence of central LFC and posterior LTP bone contusions compared to patients who have a closed femoral physis. An ACL tear should not be assumed to be present despite the presence of typical ACL bone bruise in pediatric patients, particularly those with open physes.
Knee
ACL
Ligaments
Trauma
Epidemiology
MRI
Orthopaedic Sports Medicine

### 19109 Lower socioeconomic status adversely affects access to care and the rate of instability events and bucket handle meniscus tears following anterior cruciate ligament tears

Edward S Chang
Blake M Bodendorfer
Andrew Curley
David X Wang
Christine Conroy
Mark Hopkins
Brian McCormick
Caroline Fryar
USA
Summary
Insurance status, primary language spoken, education and income impact the access to and utilization of orthopaedic care after an ACL tear, which may affect preoperative instability events and concomitant injuries such as bucket handle tears of the meniscus at the time of ACL reconstruction.
Data
Introduction
While cost is readily assumed to be a significant barrier to accessing healthcare, this may only be one of many factors that delay patients from seeking early treatment following musculoskeletal injuries. The primary aim of this study was to further define the impact of socioeconomic factors on the access to and utilization of orthopaedic care after an anterior cruciate ligament (ACL) rupture. The secondary goal was to determine if these variables were associated with preoperative instability events and bucket handle tears of the meniscus discovered at the time of surgery.
Methods
All patients undergoing ACL reconstruction at our institution from October 2015 through November 2018 were surveyed to determine income, primary language, education level and preoperative instability episodes. A chart review was then performed for insurance status, dates of injury, first visit with orthopaedics, date of surgery, intraoperative pathology, and length of follow-up. Multivariate regression analysis was utilized to select independent predictors of outcome variables. A multiple linear regression model with stepwise backward elimination was used for continuous outcome variables. Multivariate logistic analysis was used for the presence of a bucket handle meniscal tear at the time of surgery. P<0.05 was considered significant.
Results
After application of inclusion criteria, 230 patients were included with a mean±SD age of 26.5±9.9 years. Insurance status, dates of injury, first visit with orthopaedics, date of surgery, intraoperative pathology and length of follow-up were thus available for these patients. 126 of these patients responded to the survey regarding income, primary language, education level and preoperative instability episodes. Patients with government insurance saw an orthopaedic surgeon 39.4 weeks later (P=0.012) and had surgery 5 weeks later than those with private insurance (P=.016). English speakers saw an orthopaedic surgeon 55.7 weeks earlier than Spanish speakers (P=0.027) and had an average of 0.8 less instability episodes before surgery (P<0.001). Non-English speakers had an increased risk of having a bucket handle tear at the time of surgery (OR=4.62; 95CI%=1.7677–21.33). Patients with an income greater than $100,000/year had 0.325 less instability episodes before surgery (P=.040). Patients with a college degree saw a surgeon 36.0±SD weeks earlier than patients without a college degree (P=0.023). Patients with an annual household income less than$100,000 were more likely to have a bucket handle tear (OR=7.4; 95CI%=1.2–53.4).
Conclusion
Insurance status, primary language spoken, education and income impacted the access to and utilization of orthopaedic care after an ACL rupture, which may affect preoperative instability events and concomitant injuries such as bucket handle tears of the meniscus at the time of ACL reconstruction.
Knee
ACL
Ligaments
Repair/Reconstruction
Tears
Arthroscopy
Evidence Based Medicine
Instability
Lateral
Medial
Meniscus
Policy Issues
Preventative Sports Medicine

### 19110 The outcome of balance exercises and agility training for post Anterior Cruciate Ligament (ACL) reconstruction: clinical assessment

Siti Maizatul Akmal Ismail
Malaysia
Summary
Post Anterior Cruciate Ligament (ACL) reconstruction: clinical assessment
Data
Introduction
Rehabilitation process was as important as the reconstruction surgery. Rehabilitation could be initiated after the surgery to ensure safe returned of patients to sports ACL reconstruction. To evaluate of the balance exercises and agility training for post ACL reconstruction. The Primary Outcomes such as the functional score assessments were the Lysholm and the Tegner system, Secondary Outcomes were the rollimeter, thigh circumference and physical assessment. To compare balance exercises and agility training for group 1 was the 18 weeks standard regime group which had one component only such as strength exercises, and group 2 was the 24 weeks new regime which had three components advantages such as balance exercises, agility training exercises, and strength exercises.
Methods
The main objective of this researched was to show that one group had significant different values compared to the other group: ie p <0.05. Patients data from ACL reconstruction in Selayang and Sg Buloh Hospitals from 2012 to 2016, in this studied from Malaysian Knee Ligament Registry (MKLR). All patients had single bundle reconstruction with autograft hamstring tendon (Semitendinosus and Gracilis). Evaluation format were based on clinical assessment (anterior drawer, lachman, pivot shifted, laxity with rollimeter, end pointed and thigh circumference) and (Lysholm knee scoring and Tegner activity levelled scale). Group 1 was the 18 weeks Standard Regime group which had one component only such as strength exercises, and group 2 was the 24 weeks New Regime which had three components advantages such as balance exercises, agility training exercises, and strength exercises. That the following evaluation at 24 weeks for primary outcomes were Lysholm and Tegner; and secondary outcomes were the rollimeter, thigh circumference and physical assessment.
Results
The results of researched as the baseline socio-demographic characteristics between the participants in the two groups were compared. There was no significant difference in the baseline socio-demographic characteristics across the two groups. The extent and severity of measured by questionnaire demonstrated no statistically significant difference between the two groups. Summary of differences in participants’ baseline characteristics between groups. The two group were comparable in socio-demographic background, age, weight, height, gender (male/female) and BMI. After 24weeks evaluation in the two groups, there no laxity recorded in the physical examination tests such as anterior drawer test (ADT), pivot test and, Lachman test.
Discussion and Conclusions
The discussions of the researched such as the functional scores in the new regime were significantly higher than in the standard regime. The Standard Regime contains only one component: the strength exercises. The new regime contains the extra components, agility and balance in addition to strength exercises. These multiple components contribute to the higher functional scores in the new regime. The secondary outcomes such as there was a good consistency in the evaluation of laxity and the rollimeter in both groups in that there was reduced or no laxity after the operation. There was however no significant improvement and increase in thigh circumference after the rehabilitation in the two groups. In the conclusions, the primary outcomes and secondary outcomes. The New Regime (NR), had higher functional scores than Standard Regime (SR).
Knee
ACL
Ligaments
Repair/Reconstruction
Tears
Acute Patella Dislocation
Arthroscopy
Autograft
Basic Science
Biomechanics
Bones
Braces
Cartilage
Exercise Physiology
Hamstrings Tendon Injury
Infection
Infection
Lateral
Medial
Medical Aspects
Meniscus
MRI
Muscle
Nerve
Outcome Studies
Patella Tendon Injury
Patellofemoral
Patellofemoral Ligament Rupture
PCL
Popliteus
Preventative Sports Medicine
Professional Athletes/Olympians
Protective Equipment
Rehabilition/Physical Therapy
Single Bundle
Sport Specific Injuries
Sport Specific Population
Synovial
Synovitis
Tendon
Tibial Nerve

### 19119 Superior capsule reconstruction does partially restore glenohumeral stability in massive posterosuperior rotator cuff deficiency – a dynamic robotic shoulder model

Lucca Lacheta
Samuel Rosenberg
Travis Dekker
Ritesh Kashyap
Grant J Dornan
Matthew T Provencher
Peter J Millett
1Germany
2USA
Summary
SCR for Posterosuperior Rotator Cuff Tears in a Robotic Shoulder Model.
Data
Objective
To establish and report a dynamic robotic shoulder model, and assess the influence of rotator cuff tear patterns and SCR following a posterosuperior cuff tear on glenohumeral biomechanics. It was hypothesized that a posterosuperior rotator cuff tear would diminish glenohumeral stability when compared to the intact and supraspinatus tendon- deficient state, and that SCR would reverse this instability in the supra- and infraspinatus- deficient shoulder.
Methods
Twelve fresh-frozen cadaveric shoulders were tested using a 6-degrees-of-freedom robotic arm (KR 60-3; KUKA Robotics). Kinematic testing was performed in 4 conditions: (1) intact, (2) simulated irreparable supraspinatus tendon tear, (3) simulated irreparable supra- and infraspinatus tendon tear, and (4) SCR using a 3 mm thick dermal allograft (DA). Kinematic testing consisted of dynamic flexion and static 40-N superior force tests at neutral abduction, 30°, 60° and 90° of abduction. In each test, superior glenoid translation was measured, and for static testing, linear mixed-effects models were used to compare across repeated measures shoulder conditions at each abduction angle.
Results
In dynamic flexion testing, there was an average increase in superior translation of 2.1±1.7 mm for the supraspinatus cut state, 2.8±1.8 mm for the supra- and infraspinatus cut state, and 1.3±1.7 mm for SCR, when compared to the native state. In static testing, in all degrees of abduction the supraspinatus cut and the supra- and infraspinatus cut states showed a significant increase in superior translation compared to the native state (all p<0.001). Supra- and infraspinatus cut increased superior translation significantly when compared to supraspinatus cut only in neutral and 60° of abduction (p=0.030 and p=0.022). SCR was able to significantly decrease superior translation in all degrees of abduction when compared to the supra- and infraspinatus cut (all p<0.02), and in neutral position and 60° of abduction when compared to supraspinatus cut only (all p<0.05). When compared to the native state, SCR was not able to restore superior stability with a significant increase of translation for neutral position, 30°, and 60° of abduction (p<0.001).
Conclusion
Superior capsule reconstruction using a dermal allograft partially restored superior stability of the glenohumeral joint in the presence of a simulated massive posterosuperior rotator cuff tear in a dynamic and static robotic shoulder model.
Shoulder
Allograft
Glenohumeral
Tears
Biomechanics
Elderly
Infraespinatus Tendon Injury
Professional Athletes/Olympians
Supraespinoatus Tendon Injury
Tendon

### 19084 Combined reconstruction of the medial collateral ligament and anterior cruciate ligament using ipsilateral semitendinosus tendon and opposite semitendinosus with ipsilateral gracilis tendon: a minimum one-year follow-up study in NITOR.Dhaka, Bnagladesh

Dibakar Sarkar
Summary
Presented surgical technique improved both valgus and anterior stability, and led to excellent short term results at final follow up.
Data
Introduction
Combined lesions of anterior cruciate ligament (ACL) and medial collateral ligament (MCL) are frequent in adult due to sports injury and trauma. In cases of chronic anterior cruciate ligament (ACL)-medial collateral ligament (MCL) lesions, nonoperative treatment of the MCL lesion may lead to chronic valgus instability and rotatory instability. The optimal management for patients who have combined ACL-MCL injuries remains controversial. Present study wants to evaluate the surgical technique for treatment of concomitant MCL and ACL lesion and report short term outcome result in our institute.
Purpose
To present a case series of 40 patients who underwent simultaneous ACL-MCL reconstruction with a year follow-up. STUDY DESIGN: Case series; Level of evidence, 4.
Methods
From October 2017 to December 2018, a total of 40 patients with chronic ACL-MCL injuries, for which the 2 ligaments were reconstructed arthroscopically during the same surgical procedure, were studied in National Institute of Traumatology and Orthopedics Rehabilitation(NITOR),Dhaka, Bangladesh. 40 Patients with chronic ACL rupture and grade III MCL-lesion were included. All patients received surgical treatment of concomitant MCL lesion by Ipsilateral semitendinosus tendon and ACL reconstruction by opposite semitendinosus with ipsilateral gracilis tendon All patients were available for follow-up for at least 1 years. The International Knee Documentation Committee (IKDC) subjective knee scores, valgus and sagittal stability, anteromedial rotatory stability, range of motion, and complications were assessed both preoperatively and postoperatively.
Results
At follow-up, valgus and sagittal laxity were not observed in any of the patients. The mean medial knee opening was significantly reduced to 0.80 ± 0.96 mm (range, −1.2 to 2.6 mm) postoperatively compared with 8.0 ± 1.3 mm (range, 6.1 to 10.7 mm) preoperatively (P < .01). The mean postoperative side-to-side difference measured with the KT-1000 arthrometer was reduced to 0.8 ± 0.9 mm (range, −1.2 to 2.3 mm) compared with 8.4 ± 1.6 mm (range, 6.2 to 13.2 mm) preoperatively (P < .01). Preoperative anteromedial instability was seen in 76% of patients (33/40), whereas none of the patients had anteromedial rotatory instability at the last follow-up. The mean IKDC subjective score improved overall from 45.3 ± 12.0 (range, 28.7–69.0) preoperatively to 87.7 ± 8.2 (range, 65.5–100.0) at the last follow-up (P < .01). Most patients (38/40) had normal or nearly normal range of motion of the knee joint; only 2 patient (5%) had a limitation of flexion of 15° compared with the contralateral knee at the last follow-up.
Conclusion
In patients with chronic ACL-MCL lesions, presented surgical technique with simultaneous reconstruction of the ACL and MCL can significantly improve the medial, sagittal, and rotatory stability of the knee at short-term follow-up.
Knee
ACL
Arthroscopy
Instability
Ligaments
Autograft
MC Ligament
MRI
Outcome Studies
Physical Examination
X-ray

### 19107 Similar joint space measurements are obtained with supine and weightbearing anteroposterior pelvis radiographs: results of a prospective study

Austin M Looney
Blake M Bodendorfer
Vishal A Mehta
Austin M Looney
Kenneth Tepper
USA
Summary
Previous literature has presented conflicting data as to whether weightbearing and supine radiographs present different measurements for joint space width at the hip; we demonstrate no significant difference between measurements obtained during weightbearing and supine radiographs, and thus, orthopaedic surgeons may be able to avoid obtaining multiple radiographs.
Data
Introduction
Osteoarthritis and joint space narrowing of the hip have been correlated with poor outcomes and conversion to arthroplasty after hip arthroscopy. However, a standardized protocol for radiographic measurement of minimal joint space width of the hip has not been developed and there is conflicting data as to whether weightbearing and supine radiographs present different measurements for joint space width at the hip. We hypothesized that minimal joint space width would be significantly lower on the affected side in weightbearing anteroposterior pelvis radiographs versus supine radiographs. We also hypothesized that radiographs with single-leg stance would show the lowest minimal joint space width. Lastly, we hypothesized that patients older than 50 years would have significantly lower joint space width compared to younger patients.
Methods
Adult patients with hip pain were prospectively enrolled and each had single-leg and double-leg weightbearing and supine anteroposterior pelvis radiographs in a standardized position. Two independent investigators determined minimal joint space width by measuring joint space width at the lateral sourcil, middle sourcil and fovea of the hip. Differences between minimal JSW as well as interobserver reliability (interclass correlation coefficient, ICC) were calculated. One and 2-way analyses of variance (ANOVA) were used to compare the measurements. Power analysis determined that recruitment of 30 patients was necessary to achieve 90% power. P<0.05 was considered significant.
Results
Thirty-one consecutive adult patients were prospectively enrolled after informed consent and institutional review board approval. The mean ± SD age of participants was 53.8 ± 14.1. Female and male participants comprised 61.3% and 38.7% of the sample, respectively. Interobserver reliability was good (0.75 = ICC = 0.9) at the lateral sourcil and excellent (ICC > 0.9) at the middle sourcil and fovea. No significant differences in joint space width were found between supine or weightbearing radiographs for any pelvis site (P>0.770). Joint space width was significantly lower in those over 50 years of age as compared to younger patients for all stances (P=0.002).
Conclusion
These findings suggest that either weightbearing or supine anteroposterior pelvis radiographs can be used to evaluate hip joint space width. Thus, orthopaedic surgeons may be able to avoid obtaining multiple radiographs for patients who are being evaluated for hip preservation surgery presenting with hip pain.
Hip/Groin/Thigh
Arthroscopy
Cartilage
Impingement
Femoroacetabular Impingement
X-ray

### 19108 Significant variability exists in preoperative planning software measures of glenoid morphology for shoulder arthroplasty

Nicholas C Laucis
Alex R Webb
David X Wang
Daniel M Dean
Joseph L Rabe
David Matthew Lutton
Steven B Soliman
Blake M Bodendorfer
USA
Summary
As preoperative planning software and patient-specific instrumentation are both becoming more frequently utilized in an effort to provide better outcomes for patients with glenohumeral arthritis, it is important to consider the accuracy of these software programs as compared to manual measurement; this study shows a high degree of variability among programs for glenoid version and inclination.
Data
Introduction
Three-dimensional imaging and preoperative planning software have become increasingly utilized in an effort to improve component positioning in shoulder arthroplasty. We sought to assess the interrater reliability and concordance with a gold standard comparator of 4 different 3-dimensional preoperative planning programs for shoulder arthroplasty. We hypothesized that that there would be significant variation in measures of glenoid anatomy and these differences would be affected by glenoid deformity.
Methods
A retrospective review of shoulder computed tomography (CT) scans of patients undergoing shoulder arthroplasty was undertaken. An a priori power analysis was performed and it was determined that 76 CT scans were necessary to achieve 80% power. CTs were uploaded to 4 separate templating software systems (VIP, BluePrint, TrueSight, ExactechGPS). Version and inclination of glenoids as measured by each software were extracted for comparison. Interrater reliability was assessed via a 2-way mixed effects intra-class correlation coefficient (ICC). ICC was also calculated when sub-grouping glenoids by Walch classification. Lin’s concordance correlation coefficient (CCC) was calculated for each system with a musculoskeletal-trained radiologist’s measurements used as a gold standard.
Results
Shoulder CT scans for 76 patients were obtained. Measures of glenoid version differed between at least 2 modes of measurement by 5°-10° in 58 (76%) glenoids and >10° in 10 (13%) glenoids. Measures of glenoid inclination differed between at least 2 modes of measurement by 5°-10° in 69 (91%) glenoids and >10° in 36 (47%) glenoids. ICC was good-to-excellent for version but only moderate-to-good for inclination. ICC was significantly higher for Walch A glenoids as compared to Walch B glenoids. VIP had the highest concordance with gold standard while Tornier had the lowest when measuring version CCC. Tornier had the highest concordance with gold standard and ExactechGPS had the lowest when measuring inclination CCC.
Conclusion
There is significant variability in CT-based measures of glenoid version and inclination between 4 different shoulder arthroplasty templating softwares which worsens with glenoid deformity. Concordance with a gold standard comparator is also variable. Further research is needed to better understand how this variability should be accounted for during preoperative planning for shoulder arthroplasty.
Shoulder
Arthritis
Arthroplasty
Glenohumeral
Bones
Cartilage
CT-Scan
Implant
Osteoarthritis
Total Joint Replacement

### 19122 Return to play after arthroscopic management of rotator cuff tears in professional contact athletes

Luis A Vargas
Gautam Yagnik
Luis A Vargas
John W Uribe
John E Zvijac
Jacob Seiler
USA
Summary
The majority (80%) of the professional contact athletes in this series were able to return to play at the same professional level after arthroscopic management of a symptomatic rotator cuff tear.
Data
Objectives
The purpose of this study was to report on the clinical outcomes and return to play rates of professional contact athletes that underwent arthroscopic management of rotator cuff tears at our institution.
Methods
A retrospective review was performed on 10 rotator cuff tears in 9 professional contact athletes that underwent arthroscopic management of a rotator cuff tear from 2002–2019 at our institution. 8 tears occurred in elite American football players. The remaining 2 were In professional hockey players. The average age of the players was 28.7 ± 4.8 years. The primary outcome measure was the ability to return to play and the number of games played after surgery. Return to play and career length data were collected through publicly available internet sources (NFL, CFL and NHL statistical websites) as well as from the team’s medical staff.
Results
80% of the athletes that underwent arthroscopic management of a rotator cuff tear in this study were able to return to play at the same professional level. The average age of the players that returned to play was 27.3 ± 4.2 years and the average time to return to play was 7.9 ± 1.9 months. The majority of the injuries in American football (6 of 8) occurred in defensive players. The 2 tears occurred in hockey were offensive players. All regained sufficient range of motion, strength and function to participate in at least one regular season game. For the football players, the average playing experience after surgery was 32 ± 25 games played. For the hockey players, was 22 ± 11games played. 9 of the 10 tears were full thickness that underwent arthroscopic repair while 1 was a partial tear that was debrided. The average tear size was 1.95 ±0.9 cm. The average number of suture anchors used was 1.35 ± 0.7. All tears involved the supraspinatus rotator cuff tendon and 4 were classified as small tears (<1cm), 3 as medium tears (1–3 cm) and 2 as large tears (3–5 cm). 7 of the 10 tears underwent acute surgical repair (<2 weeks from date of injury), while 3 players underwent delayed surgical intervention at the end of the season. Post-operative imaging was available in 8 of the 10 tears and 7 of 8 (88%) demonstrated a healed repair. No intra-operative complications were noted. 2 players with large (3–5 cm) full thickness tears did not return to play. The average age was 34.5 years and both had > 10 years of professional playing experience. One was an NFL player with a repair failure at 6 months on post-operative imaging and elected to retire. The second was an NHL player that retired for reasons unrelated to his shoulder, despite a good clinical outcome and a healed repair on post-operative imaging.
Conclusions
The majority (80%) of athletes in this series were able to return to play at the same professional level after arthroscopic surgery. Older players with > 10 years of professional experience and large rotator cuff tears were less likely to return to play after surgical intervention
Shoulder
Arthroscopy
Glenohumeral
Tears
Bursa
Epidemiology
Evidence Based Medicine
Impingement
Infraespinatus
Infraespinatus Tendon Injury
MRI
Muscle
Outcome Studies
Physical Examination
Repair/Reconstruction
Sport Specific Injuries
Subacromial Bursa
Subescapular
Subescapular Tendon Injury
Supraespinatus
Supraespinoatus Tendon Injury
Sutures/Knots/Anchors
Team Physician
Tendon
Teres Minor
Teres Minor Injury
Trauma
Ultrasound
X-ray

### 19200 Arthroscopic meniscal allograft transplantation with intermeniscal ligament tenodesis is effective in reducing initial extrusion

Nicolas Pujol
France
Summary adding a tenodesis or reconstruction of the IML can significantly limit early extrusion of the meniscal allograft. Clinical outcomes are not different when compared to standard procedure, but it may justify a long-term assessment of these patients in order to know if the incidence of osteoarthritis would decrease with technique.
Data
Background
Meniscal allograft transplantation (MAT) is indicated in the treatment of post meniscectomised knee syndrome in young patients without severe cartilage loss. Its clinical efficiency is well established at short to mid-term but osteoarthritis still continues to progress with time. A meniscal extrusion occurs often initially and is irreversible. The aim of this study was to evaluate results of arthroscopic meniscal allograft transplantation associated with a reconstruction of the intermeniscal ligament (IML). The hypothesis was that concomitant reconstruction of the IML would decrease the incidence of early allograft extrusion when compared to conventional soft-tissue techniques.
Materials and methods
This is a monocentric retrospective comparative study of patients operated on between 2011 and 2018. There were two groups: Group IML (MAT with IML repair, n=14) and Group no IML (MAT without IML repair, n=20). Clinical outcomes were evaluated by using the KOOS score at last follow-up and by assessing the rate of secondary surgical procedures. MRI was performed at a minimum of 12 months (mean 35±25 months) to determine absolute and relative meniscal extrusion, sagittal anterior and posterior extrusion and index of cartilage coverage in the frontal and sagittal cuts.
Results
The KOOS score was not significantly different between the two groups. There was no secondary procedure in Group IML and 4 in Group no IML (13%). There was a meniscal extrusion of the allograft in 43% (6/14) of the cases in group IML versus 85% (17/20) in the no IML Group (p<0.03). Absolute meniscal extrusion was 2,9 mm ([2,2- 3,6] SD=1,2) in Group IML and 5,4 mm ([4,1 - 6,7]; SD=2,9) (p = 0,004) in Group no IML.
Discussion adding a tenodesis or reconstruction of the IML can significantly limit early extrusion of the meniscal allograft. Clinical outcomes are not different when compared to standard procedure, but it may justify a long-term assessment of these patients in order to know if the incidence of osteoarthritis would decrease with technique. Level of evidence: IV; retrospective cohort study
Knee
Allograft
Meniscus
Arthroscopy
MRI

### 19155 Sequential change in posterior tibial translation after posterior cruciate ligament reconstruction: risk factors for residual posterior sagging

Yuta Tachibana
Yoshinari Tanaka
Kazutaka Kinugasa
Shuji Horibe
Japan
Summary
This study shows (1) posterior tibial translation significantly reduced from 10.1±2.3 mm to −0.8±1.2 mm immediately after PCLR, but it significantly increased within 3 months (4.1±2.7 mm) and no further progression was observed over 2 years (4.4 ± 1.9 mm), and (2) preoperative grade III injury was independently associated with residual posterior sagging (OR: 26.8; 95% CI: 2.0–282.7; P<0.001).
Data
Purpose
Residual posterior sagging may occur after posterior cruciate ligament (PCL) reconstruction (PCLR), yet when it mainly occurs is not fully understood. This study aimed to elucidate sequential changes in radiographic posterior tibial translation (PTT) through PCLR.
Methods
Radiographic findings from 22 patients who underwent bi-socket double-bundle PCLR for isolated grade II or III PCL injury from January 2007 to December 2016 with at least two years of follow-up (mean: 4.5 years; range: 2–12 years) were retrospectively investigated. On lateral radiographs with gravity sag views, PTT (side-to-side difference of the tibiofemoral relationship) was serially measured preoperatively and immediately, three and six months, and one and two or more years postoperatively. Risk factors for residual posterior sagging, indicating the PTT was 5 mm or more (grade = II) at two or more years postoperatively, were also investigated using a multivariable logistic regression analysis.
Results
The PTT was 10.1 ± 2.3 mm preoperatively, then was reduced significantly to −0.8 ± 1.2 mm immediately after surgery (P < 0.001). Subsequently, the PTT was significantly increased by 5.2 ± 2.6 mm up to 4.1 ± 2.7 mm at three months postoperatively (P < 0.001). Then, no significant changes at six months (4.1 ± 2.5 mm), one year (4.4 ± 2.1 mm), and two or more years (4.4 ± 1.9 mm) postoperatively were observed.Seven cases of residual PTT with grade II at two or more years after PCLR were identified, whereas no patient underwent revision PCLR due to subjective recurrent instability and no instance of grade III injury persisted to the final follow-up. PTTs with residual posterior sagging were significantly larger than those without residual posterior sagging at all time points except for immediately postoperatively [preoperatively, 9.1 ± 1.6 vs. 12.2 ± 2.2 mm (P < 0.001); immediately postoperatively, −0.8 ± 1.3 vs. −0.8 ± 0.8 mm (P = 0.950); three months postoperatively, 2.7 ± 1.6 vs. 7.0 ± 1.8 mm (P < 0.001); and two or more years postoperatively, 3.4 ± 1.0 vs. 6.6 ± 1.4 mm (P < 0.001)]. Multivariate logistic regression analysis showed preoperative grade III injury was independently associated with residual posterior sagging (odds ratio: 26.809; 95% confidence interval: 2.037–282.672; P < 0.001). Meanwhile, the receiver operating characteristic analysis highlighted a cutoff value of 12.64 mm for the preoperative PTT as the optimal threshold for differentiating the two groups with and without residual posterior sagging (sensitivity: 71.4%; specificity: 100.0%).
Conclusion
The initially reduced postoperative PTT significantly increased within three months with conventional rehabilitation protocols but no progression was observed up to 4.5 years after PCLR. Preoperative grade III injury was independently associated with residual posterior sagging. Therefore, we recommend that clinicians consider the preoperative PTT as a risk factor for postoperative residual posterior sagging and take meticulous care, especially in the early postoperative period, to protect the transplanted PCL graft even if the PTT could be reduced immediately after PCLR.
Knee
Ligaments
PCL
Repair/Reconstruction
Arthroscopy
Autograft
Biomechanics
Double Bundle
Instability
Outcome Studies
X-ray

### 19140 Classic vs congruent-arc latarjet procedure in athletes with recurrent glenohumeral instability and a significant glenoid bone loss

Luciano A Rossi
Ignacio Tanoira
Tomás David Gorodischer
Maximiliano Ranalletta
Argentina
Summary most of the athletes with recurrent glenohumeral instability who underwent either classic or congruent arc Latarjet surgery were able to return to sports at the same level they had prior to injury with full recovery of shoulder function and a similary rate of complications, regardless of the surgical technique used.
Data
Shoulder
Autograft
Glenohumeral
Instability
CT-Scan
Labrum
Sport Specific Injuries
Sport Specific Population

### 19197 Survivorship and patient-reported outcomes after comprehensive arthroscopic management of glenohumeral osteoarthritis: minimum 10-year follow-up

Justin W Arner
Bryant Elrick
Daniel B Haber
Philip Nolte
Marilee P Horan
Peter J Millett
USA
Summary
Significant improvement in patient reported outcomes were sustained at minimum 10-year follow-up in young patients with GHOA who underwent a CAM procedure.
Data
Background
Few long-term outcome studies exist evaluating glenohumeral osteoarthritis (GHOA) treatment with arthroscopic management.
Purpose
To determine outcomes, risk factors for failure, and survivorship for the comprehensive arthroscopic management (CAM) procedure for the treatment of GHOA at minimum 10-year follow-up. Study Design: Case series; Level of evidence, 4.
Methods
The CAM procedure was performed on a consecutive series of patients with advanced GHOA who opted for joint preservation surgery that otherwise met criteria for total shoulder arthroplasty (TSA). At minimum 10-year follow-up, pre- and post-operative outcome measures collected included the American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), Short Form-12 (SF-12) Physical Component Summary (PCS), visual analog scale for pain, and satisfaction scores. Kaplan-Meier survivorship analysis was performed with failure defined as progression to arthroplasty.
Results
Thirty-eight CAM procedures were performed with 10-year minimum follow-up (range, 10–14 years) with a mean age of 53 years (range, 27–68) at time of surgery. Survivorship was 75.3% at 5 years and 63.2% at minimum 10 years. Those who progressed to arthroplasty did so at a mean of 4.7 years (range, 0.8–9.6 years). For those who did not undergo arthroplasty, ASES scores significantly improved post-operatively at both 5 and 10 years (63.3–89.6, p<0.001; 63.3–80.6, p=.007). CAM failure was associated with severe pre-operative humeral head incongruity in 93.8% of failures compared to 50.0.% of patients who did not go onto arthroplasty (p= 0.008). Median satisfaction was 7.5 out of 10.
Conclusions
Significant improvement in patient reported outcomes were sustained at minimum 10-year follow-up in young patients with GHOA who underwent a CAM procedure. Survivorship rate at minimum 10-year follow-up was 63.2%. Humeral head flattening and severe joint incongruity were risk factors for CAM failure. The CAM procedure is an effective joint preserving treatment for GHOA in appropriately selected patients with sustained positive outcomes at 10 years.
Shoulder
Arthritis
Endoscopy
Glenohumeral
Axilar Nerve
Bones
Bursa
Capsuloligamentous Complex
Cartilage
Coracohumeral Ligament
Humeral Tranvers Ligament
Inferior Glenohumeral Ligament
Ligaments
Medial Glenohumeral Ligament
Nerve
Osteoarthritis
Sport Specific Population
Subacromial Bursa
Superior Glenohumeral Ligament
Synovial
Synovitis

### 19156 Radiographic indices are not predictive of clinical outcome among 1,735 patients indicated for hip arthroscopy: a machine learning analysis

Prem N Ramkumar
Jaret M Karnuta
Heather S Haeberle
Spencer Sullivan
Danyal H Nawabi
Anil S Ranawat
Bryan T Kelly
Benedict U Nwachukwu
USA
Summary
No radiographic indices were found to be predictive of achieving the minimal clinically important difference (MCID) for the modified Hip Harris Score (mHHS), the Hip Outcome Score (both HOS-ADL and HOS-SS) or the international hip outcome tool (iHOT-33) in patients that underwent hip arthroscopy at either one or two-year postoperative follow-up.
Data
Background
The relationship between the pre-operative radiographic indices for femoroacetabular impingement syndrome (FAIS) and post-operative patient-reported outcome measures (PROMs) continues to be under investigation with inconsistent findings reported. The purpose of the present study was to apply a machine learning model to determine which preoperative radiographic indices, if any, among patients indicated for arthroscopic correction of FAIS predict whether a patient will achieve the minimal clinically important difference (MCID) for one- and two-year PROMs.
Methods
A total of 1,735 consecutive patients undergoing primary hip arthroscopy for FAIS were included from an institutional hip preservation registry. Patients underwent pre-operative computed tomography (CT) of the hip, from which the following radiographic indices were calculated by a musculoskeletal radiologist: alpha angle; beta angle; sagittal center edge angle; coronal center edge angle; neck shaft angle; acetabular version and femoral version angle. PROMs were completed preoperatively, one year postoperatively, and two years postoperatively for the modified Harris Hip Score (mHHS), the Hip Outcome Score (HOS) Activities of Daily Living Subscale (HOS-ADL) and Sport Specific Subscale (HOS-SS) as well as the international hip outcome tool (iHOT-33). Random forest models were created for each outcome measure at one and two years follow-up, with each outcome measures’ MCID used to establish clinical meaningfulness. Data inputted into the models included ethnicity, laterality, sex, age, body mass index (BMI), and radiographic indices. Comprehensive and separate models were built specifically to assess association for the alpha angle, femoral version angle, coronal center edge angle, McKibbin index, and hip impingement index with respect to each PROM.
Results
The mean difference between one-year and two-year PROMs compared to pre-operative levels exceeded the respective MCIDs for the cohort. As evidenced by poor AUCs and p-values > 0.05 for each model created, no combination of radiographic indices or isolated index (alpha angle, coronal center edge angle, femoral version angle, McKibbin index, hip impingement index) were significant predictors of clinically significant outcome improvement on the mHHS, HOS-ADL, HOS-SS, or iHOT-33.
Conclusion
In patients appropriately indicated for FAIS corrective surgery, clinical improvements can be achieved regardless of pre-operative radiographic indices, such as femoral version, coronal center edge angle and the alpha angle. No specific radiographic parameter or combination of indices was found to be predictive of reaching the MCID for any of the four studied hip specific PROMs at either one or two years follow-up.
Hip/Groin/Thigh
Arthroscopy
Impingement
CT-Scan
X-ray

### 19170 MRI after ACL reconstruction demonstrates that hamstring grafts heal and integrate at different rates

Sven Edward Putnis1
Takeshi Oshima2
Antonio Klasan2
Samuel Grasso2
Thomas Neri3
Myles RJ Coolican2
Brett A Fritsch2
David A Parker2
1UK
2Australia
3France
Summary
New MRI analysis at 1 and 2 years after ACL reconstruction demonstrates that hamstring grafts heal and integrate at different rates.
Data
Purpose
To establish whether a hamstring ACL reconstruction graft changes in appearance on MRI between 1 and 2 years, and whether it affects a patient’s ability to return to sport.
Methods
Patients with a hamstring autograft ACL reconstruction using adjustable suspensory fixation had MRI and clinical outcome measures at 1 and minimum 2 years. Signal intensity ratio (SIR) at multiple areas using oblique reconstructions both parallel and perpendicular with the graft were calculated alongside tunnel aperture sizes. Clinical outcome was side to side anterior laxity, and patient reported outcome measures (PROMs).
Results
Forty-two patients had full datasets. At 1 year the mean SIR for the graft was 2.7 ± 1.2, with proximal graft signal significantly higher than distal. Overall, there was no significant change at by 2 years apart from those with the highest proximal graft signal (SIR > 4) at 1 year. This group had a reduction in signal and were also most likely to have a reduction in tunnel aperture area. The finding of tunnel aperture area reduction between 1 and 2 years was significant across the full cohort (mean tibial −6.9 mm2, p< 0.001, mean femoral −13.5 mm2, p< 0.001). A high patient sporting level was seen, with a median Tegner activity score of 6 [5–10], with a third of patients scoring either a 9 or 10. Overall, PROMs were not affected by MRI appearance.
Conclusions
In the majority of patients graft signal does not change after one year. However, a significant reduction is seen in those with high signal at one year. Tunnel contraction correlates with a reduction in graft SIR suggesting this could be a useful measure of graft integration.
Knee
ACL
Instability
Ligaments
Repair/Reconstruction
Arthroscopy
MRI
Outcome Studies
Rehabilition/Physical Therapy
Sport Specific Population

### 19120 Superior labrum anterior-posterior (Slap) repair versus subpectoral biceps tenodesis for isolated slap II lesions in overhead athletes aged younger 35 years: a comparison of minimum two-year outcomes

Lucca Lacheta1
Marilee P Horan2
Travis Dekker2
Brandon Goldenberg2
Grant J Dornan2
Peter J Millett2
1Germany
2USA
Summary
Both techniques of SLAP repair and subpectoral biceps tenodesis provide excellent clinical results with high return to overhead sports rate and low failure rate in a young and high-demanding patient cohort for the treatment of isolated SLAP type II lesions
Data
Objectives
To evaluate clinical outcomes and return to sports rates in overhead athletes aged younger than 35 years suffering from symptomatic SLAP type II lesions who have undergone either biceps tenodesis or SLAP repair.
Methods
A retrospective analysis of prospectively collected data was performed in patients who underwent subpectoral biceps tenodesis (group I) or SLAP repair (group II) for the treatment of isolated SLAP type II lesions, were younger than 35 years at time of surgery, participated in overhead sports, and were at least two years out from surgery. Clinical outcomes were assessed by the use of the American Shoulder and Elbow Society Score (ASES), Single Assessment Numerical Evaluation Score (SANE), Quick Disabilities of the Arm, and Shoulder and Hand Score (QuickDASH) and the General Health SF-12 physical component. Return to sports and patient satisfaction were documented. Clinical failures requiring revision surgery and complications were reported.
Results
Minimum 2-year follow-up was obtained in 12/14 (85.7%) patients in group I and in 23/27 (85%) patients in group II. Preoperative baseline scores between both groups showed no significant differences (p > 0.05). When group I was compared to group II, no significant differences in postoperative outcome scores were detected (p > 0.05). For biceps tenodesis (Group 1) vs SLAP repair (Group II): ASES score was mean 91.6 ± 11.3 vs 88.6 ± 16.9, SANE score was mean 77.5 ± 28.0 vs. 82.3 ± 24.4, QuickDASH score was mean 9.2± 12.2 vs 9.4 ± 14.5, and SF-12 was mean 52.0 ± 6.1 vs 52.6 ± 7.8. No difference in return to sports rate (91% vs 91%, p > .05) was noted. 1 patient in group I and 2 patients in group II failed.
Conclusion
This study showed that both techniques of SLAP repair and subpectoral biceps tenodesis provide excellent clinical results with high return to overhead sports rate and low failure rate in a young and high-demanding patient cohort for the treatment of isolated SLAP type II lesions.
Shoulder
Glenohumeral
Instability
Repair/Reconstruction
Arthroscopy
Elderly
Labrum
Outcome Studies
Professional Athletes/Olympians
Sport Specific Injuries
Sport Specific Population
Tendon

### 19192 Outcome comparison of graft bridging and superior capsule reconstruction for large to massive rotator cuff tears

Jinrong Lin
Yaying Sun
Shaohua Liu
Zheci Ding
Jiwu Chen
China
Summary
In general, graft bridging showed significantly better clinical and functional outcomes postoperatively than superior capsule reconstruction, with a similar complication rate.
Data
Background
Graft bridging (GB) and superior capsule reconstruction (SCR) were developed to treat large to massive rotator cuff tears (RCTs); however, the outcome differences between GB and SCR remain unclear.
Purpose
To systematically review and compare the outcomes of GB and SCR for large to massive RCT.
Methods
A systematic review was performed via a comprehensive search of PubMed, Embase, and the Cochrane Library. Studies of GB or SCR were included according to the inclusion and exclusion criteria. The primary outcome was Constant-Murley score at the final follow-up. Secondary outcomes included the American Shoulder and Elbow Surgeons score, visual analog scale score for pain, active shoulder range of motion, and graft healing rate. Complication rate was the safety outcome measure. Outcomes were summarized into group SCR and group GB, and the results were compared statistically (P<0.05).
Results
A total of 23 studies were included in this review: 238 repairs from the 5 studies in group SCR and 593 repairs from the 18 studies in group GB. For group SCR and group GB, the mean age was 61.6 and 63.3 years, and the mean follow-up was 18.0 and 40.1 months, respectively. Overall, both procedures demonstrated improvement of clinical outcomes. When compared with group SCR, group GB had significantly higher mean differences of the Constant-Murley score (41.9 vs 19.8), American Shoulder and Elbow Surgeons score (39.3 vs 33.8), visual analog scale score for pain (4.4 vs 3.4), and active external rotation at side (15.3 vs 9.3). No statistically significant difference was detected in the mean difference of active forward flexion, internal rotation, abduction, and graft healing rate between the groups. The complication rates were 0.84% (2 of 238) in group SCR and 0.67% (4 of 593) in group GB.
Conclusion
In general, GB showed significantly better clinical and functional outcomes postoperatively than SCR, with a similar complication rate. The available fair-quality evidence suggested that GB might be a better choice for large to massive RCT. More high-quality randomized controlled studies are required to further evaluate the relative benefits of the 2 procedures.
Shoulder
Acromio Clavicular
Implant
Tears
Allograft
Autograft
Biomechanics
Elderly
Failed
MRI
Outcome Studies
Repair/Reconstruction
Ultrasound

### 19123 Anterior cruciate ligament reconstruction with concomitant meniscal repair: is ACL graft choice predictive of meniscal repair success?

Hytham S Salem
Laura J Huston
Eric C McCarty
Armando F Vidal
Jonathan T Bravman
Kurt P Spindler
Rachel M Frank
USA
Summary
Meniscal repairs performed at the time of allograft ACL reconstruction are more likely to fail than those performed with bone-patellar tendon-bone autograft ACL reconstruction.
Data
Background
Meniscal repair is commonly performed at the time of anterior cruciate ligament (ACL) reconstruction. However, the effect of ACL graft type on meniscal repair outcomes is unknown. The purpose of this study was to determine if ACL graft type influences the outcome of meniscal repairs performed at the time of ACL reconstruction. We hypothesize that meniscal repairs fail at the lowest rate when concomitant ACL reconstruction is performed with bone-patellar tendon-bone (BTB) autograft.
Methods
Patients who underwent meniscal repair at the time of primary ACL reconstruction and had a minimum of 6-year follow-up data were identified from a longitudinal, prospective cohort. Meniscal repair failures, defined as any subsequent surgical procedure addressing the meniscus repaired at index surgery, were identified. After identifying patients with a subsequent meniscal surgery, operative notes were reviewed to accurately classify pathology and treatment of meniscus re-injuries. A logistic regression model was built to assess the association of ACL graft type, patient-specific factors (age, sex, and body mass index [BMI]), baseline Marx activity rating score, and meniscal repair location (medial or lateral) with the occurrence of repair failure at 6-year follow-up. Statistically significant results were determined by 95% confidence intervals that did not include the null value (1).
Results
A total of 646 patients were included. (BTB and soft tissue (ST) autografts were used in 55.7% and 33.9% of cases, respectively. Various allografts were utilized in the remaining cases (10.4%). We identified 101 patients (15.6%) with a documented meniscal repair failure. The odds of meniscal repair failure within 6 years of index surgery for the BTB autograft group were 2.34 times that of the allograft group (95% CI: 1.1–4.9; P = 0.02). The odds of failure were 68% higher with medial versus lateral repairs (95% CI: 0.41–0.83; P < 0.001). There was a statistically significant, nonlinear relationship between baseline Marx activity level and the risk of meniscal repair failure—patients with low or high baseline activity were at the highest risk (odds ratio [OR]: 1.17; 95% CI: 1.05–1.31; p=0.004). No significant differences in meniscal repair failure rate were observed based on patient age (OR: 0.87; 95% CI: 0.6–1.3; P = 0.48), sex (OR: 0.91; 95% CI: 0.6–1.5; P = 0.69) or BMI (OR: 0.80; 95% CI: 0.6–1.1; P = 0.13).
Conclusion
Meniscal repairs performed at the time of ACL reconstruction with allograft are 2.3 times more likely to fail than those performed with BTB autograft. Medial repairs fail at a significantly higher rate than lateral repairs. Patients with low or high baseline activity levels are also at an increased risk.
Knee
Meniscus
Repair/Reconstruction
Tears
ACL
Allograft
Autograft
Evidence Based Medicine
Failed
Instability
Lateral
Ligaments
Medial
Outcome Studies
Physical Examination
Preventative Sports Medicine

### 19198 Dair treatment in early infection of unicompartmental knee arthtroplasty: what do we know?

Angela Brivio1
Jürgen Martin2
Nicolò Castelnuovo1
David S Barrett3
1Italy
2Germany
3UK
Summary
Following UKA a significantly higher proportion of the knee joint remains of native tissue. This may explain lower rate of infection in comparison to TKA, but may alter the response to the rare challenge of infection. It is suggested that as the higher proportion of the knee is natural around the much smaller implant of UKA, the knee immunological status and natural defenses are more effective tha
Data
Background
Infection after Unicompartmental Knee Arthroplasty (UKA) is an uncommon but severe complication, not well studied, with a lower incidence compared to a Total Knee Arthroplasty (TKA). Little data is available regarding the modern treatment of Periprosthetic Joint Infection (PJI) after UKA. The purpose of this article is to present the results of the largest multicenter clinical study of UKA PJI treated with DAIR.
Methods
In this retrospective study, clinical data was collated between January 2016 and December 2019. Twenty patients had early infections, 19 of whom were submitted to Debridment, Irrigation, polyethylene liner exchange with Implant Retention (DAIR) and intravenous antibiotic therapy followed by oral treatment.
Results
DAIR procedure showed an overall survivorship free from septic reoperation of 84.2%. The overall survivorship free from all-cause reoperation was 78.9%. The usage of DAIR procedure had a higher than expected success against earlier published data for UKA and significantly better than the same procedure in TKR. Analysis of UKA infected cases reveals the most common bacteria are coagulase-negative Staphylococcus, Staphylococcus aureus, and group B Streptococcus. Three patients underwent a second DAIR procedure successfully: one of these patients had a TKA for medial osteoarthtritis and one was lost at follow up (FU). All other cases had no recurrence at last FU.
Conclusion
Following UKA a significantly higher proportion of the knee joint remains of native tissue. This may alter the response to the rare challenge of infection. Surgeons might wish to adopt a slightly different strategy than in TKA infection, with more emphasis on the less invasive and potentially more successful DAIR procedure.
Knee
Arthritis
Failed
Bones
Elderly
Epidemiology
Evidence Based Medicine
Infection
Ligaments
Osteoarthritis
Synovial
Synovitis
Total Joint Replacement
X-ray

### 19139 Local Anaesthetic Infiltration (Lia) is equally effective as adductor nerve blocks for pain relief in Anterior Cruciate Ligament (Acl) Reconstructions

Sonal Sonwalkar
Sanjeev Anand
Martin Stone
UK
Summary
LIA technique provided equally good pain relief following ACL reconstruction when compared to ACB, while allowing for earlier rehabilitation, mobilisation and discharge.
Data
Objectives
To determine the effectiveness of LIA compared to adductor nerve blocks in providing pain relief and opiate usage in ACL reconstructions.
Materials and Methods
In a consecutive series of ACL reconstructions, patients received three different postoperative regional and/or anaesthetic techniques for pain relief. Three groups were studied: group 1: general anaesthetic (GA)+ adductor canal block (ACB) (n=38); group 2: GA + ACB + local infiltration anaesthesia (LIA) (n=31) and group 3: GA+LIA (n=36). Adductor block was given under ultrasound guidance. LIA involved infiltration at skin incision site, capsule, periosteum and in hamstring harvest tunnel. Rest of analgesic medications were similar between the three groups as per standard multimodal analgesia (MMA). Patients were similar in demographics distribution and surgical technique/procedure. The postoperative pain and total morphine requirement were evaluated and recorded. The postoperative pain was assessed VAS at 0 hrs, 2 hrs, 4 hrs, weight bearing (WB) and discharge (DC).
Results
There was no statistically significant difference in opiates intake amongst the three groups. When comparing VAS scores; there were no statistical difference between the groups at any of the time intervals that VAS was measured. Group 1 VAS scores at 0 hrs were mean(m) and 95%confidence intervals (CI) m=30.47±9.95 mm; at 2 hrs m=30.64±7.37 mm; at 4 hrs m=33.57±5.8 mm; at WB m=35.68±5.47 mm; and at DC m=36.89±5.67 mm. Group 2 VAS scores were at 0 hrs m=32.09±3.54 mm; at 2 hrs m=30.34±2.6 mm; at 4 hrs m=30.96±1.84 mm; at WB m=30.64±1.42 mm; and at DC m=30.96±2.42 mm. Group 3 VAS scores were at 0 hrs m=30.5±8.76 mm; at 2 hrs m= 34.38±6.82 mm; at 4 hrs m=36.16±6.5 mm; at WB m=34.05±4.85 mm; and at DC m=35.44±4.73 mm. However, the GA+LIA group hospital’s LOS (MD=2.31 hrs, SD=0.75) was almost half that of GA+ACB group (4.24 hrs, SD=1.08); (conditions t(72)=8.88; p=0.000). There was no statistical significance in the incidence of adverse effects amongst the groups.
Conclusion
LIA technique provided equally good pain relief following ACL reconstruction when compared to ACB, while allowing for earlier rehabilitation, mobilisation and discharge.
Knee
ACL
Autograft
Ligaments
Trauma
Outcome Studies
Rehabilition/Physical Therapy

### 19150 What is the ideal hinge axis position to reduce tibial slope in opening wedge high tibial osteotomy?

Claire D Eliasberg
Kyle Hancock
Erica Swartwout
Hugo Robichaud2
Anil S Ranawat1
1USA
Summary
Distalization/flexion and external rotation of the hinge axis position led to stepwise increases in posterior tibial slope, whereas proximalization/extension and internal rotation led to decreases in posterior tibial slope.
Data
Background
High tibial osteotomy (HTO) is a versatile surgical procedure which has been utilized in the treatment of medial compartment osteoarthritis, ligamentous instability, anterior cruciate ligament (ACL) deficiency, meniscal deficiency, and focal cartilage defects. Hinge axis position has been identified as a significant determinant in altering posterior tibial slope (PTS) during high tibial osteotomy (HTO). Therefore, when preparing for medial opening wedge HTO, careful preoperative planning is essential in order to determine not only the degree of correction in the coronal plane, but also to properly assess the change in PTS that will arise as a result of this coronal plane correction, a variable that can be challenging to predict. The purpose of this study was to evaluate the effect of hinge axis position on PTS in medial opening wedge HTO.
Methods
Adults with medial compartment osteoarthritis who had CT scans available that were amenable to Bodycad Osteotomy software analysis were included. Virtual osteotomies were performed modeling a 10 mm medial opening wedge gap. The hinge axis was rotated internally and externally and proximalized/extended and distalized/flexed with respect to the anterior tibial cortex for 5, 10, 15 and 20 degrees. Each resultant PTS was recorded and compared with the results obtained from the true lateral hinge position and with the preoperative PTS.
Results
CT scans from ten patients were utilized. There were strong linear correlations with each hinge axis position change and the resultant PTS. The trendline differences were statistically significant by single factor ANOVA (p<0.001). PTS decreased for an anterolateral hinge, while it increased for a posterolateral hinge. Linear regression analysis demonstrated that rotating the hinge axis by 9.0° externally or angulating the hinge axis by 21.8° of distalization/flexion would result in increasing the tibial slope by 1°, whereas rotating the hinge axis by 8.7° internally or angulating the hinge axis by 21.6° of proximalization/extension would decrease the tibial slope by 1°.
Conclusions
Distalization/flexion and external rotation of the hinge axis position led to stepwise increases in PTS, whereas proximalization/extension and internal rotation led to decreases in PTS. This suggests that when performing medial opening wedge HTO and aiming to decrease PTS, the surgeon should aim to achieve maximal internal rotation (producing an anterolateral hinge), as well as proximalization/extension of the hinge axis. This study quantifies and provides a model for the effect of hinge axis position for a predetermined angular correction on PTS.
Knee
Bones
Osteoarthritis
Osteotomy

### 19280 Avoiding stem extension during revision total knee arthroplasty

Jean-Yves Jenny
France
Summary
Both tibial and femoral extension stems after revision TKA were necessary only in 48% of the cases.
Data
Introduction
Revision implants with long stem extensions are routinely implanted in revision TKAs, but they involve more bone loss. The present study was designed to evaluate the possibility of implanting routinely primary implants instead of revision implants during revision TKAs. The hypothesis of this study will be that the survival rate of primary TKAs implanted for revision cases will not be negatively impacted in comparison to revision implants.
Material and Methods
All patients undergoing a TKA exchange for any reason between January 2013 and December 2017 were included. All patients were operated on by two senior surgeons experienced with revision TKA. The target for reimplantation was: neutral mechanical alignment, orthogonal position of both implants in anteroposterior and lateral planes, restoration of the joint line within 2 mm of the native one, medial and lateral gaps in flexion and in extension less than 5 mm. All these parameters were controlled by a navigation system. Bone loss was filled by bone allografting and/or metal augments without increasing bone defects by additional resection. The smallest implant was chosen, which allowed primary fixation of both implants and graft/augment. Information about follow-up was collected from the individual patient files. All patients were recalled for clinical and radiological examination. The survival curve was plotted.
Results
158 patients were included: 96 women and 62 men, with a mean age at surgery of 71 ± 10 years. The mean body mass index was 31.6 ± 6.72 kg/m². Reasons for revision were infection (65%), aseptic loosening (13%), implant malposition (10%), and instability (6%). 11 cases were reimplanted with a smaller implant than the implant removed (Group A). 37 cases were reimplanted with the same size of implant than the implant removed (Group B). 31 cases were reimplanted with a longer implant than the implant removed for only one tibial or femoral component (Group C), and 79 cases were reimplanted with a longer implant than the implant removed for both components (Group D). There was no significant difference between all groups for demographic data: age, gender, body mass index, ASA score. Bone defects were significantly larger in group D than in all other groups. The survival rate of the group A was 100% at 5 years. The survival rate of the group B was 96% at 5 years. The survival rate of the group C was 94% at 5 years. The survival rate of the group D was 92% at 5 years. The differences were not statistically significant.
Discussion
Reimplantation of a TKA smaller or with the same size than the removed implant was possible in 30% of the cases, without a negative impact on the survival rate after 5 years. Both tibial and femoral extension stems were necessary only in 48% of the cases. Navigation offers the possibility to decrease significantly the size of the implants during TKA revision. This might allow preserving bone stock for a possible repeat revision, especially in cases of infected TKA where the failure rate is significantly higher.
Knee
Bones
Osteoarthritis
Total Joint Replacement

### 19374 Diagnosis of peri-prosthetic knee infection: what do the new MSIS definition criteria bring?

Jean-Yves Jenny
Nicolas Giordano
France
Summary
The new MSIS classification offered only minor, non significant increase of the diagnostic accuracy in comparison to the conventional criteria.
Data
Objectives
Accurate diagnosis of peri-prosthetic joint infection is critical to allow adequate treatment. Currently, the criteria of the Musculo-Skeletal Infection Society (MSIS) serve as a validated reference tool. More recently, these criteria have been modified for better accuracy. The goal of this study was to compare retrospectively the diagnostic accuracy of these two different tools in cases of known peri-prosthetic total knee arthroplasty (TKA) infection or in aseptic cases and to analyze one additional criterion: presence of an early loosening (prior to 2 years after implantation).
Methods
All cases of knee prosthesis exchange operated on at our department during the year 2017 have been selected. There were 130 cases in 127 patients: 67 men and 60 women, with a mean age of 69 years. 74 cases were septic and 53 cases were aseptic. All criteria included in both classifications were collected: presence of a fistula, results of bacteriological samples, ESR and CRP levels, analysis of the joint fluid, histological analysis. Additionally, the presence of an early loosening was recorded. The diagnosis accuracy of the classical MSIS classification and of the 2018 modification were assessed and compared with a Chi-square test at a 0.05 level of significance.
Results
The conventional MSIS classification correctly discriminated between infected and non-infected cases in 128/130 cases (98%). There were two failures by infected cases: one case was considered infected with no major criteria and only three minor criteria; one case was considered infected with no major criteria and only two minor criteria. There was no failure by non-infected cases. The new MSIS classification correctly discriminated between infected and non-infected cases in 129/130 cases (99%). There was one single failure by infected cases: one case was considered infected despite a score of 4 points. There was no significant difference between the diagnostic accuracy of both classifications. The presence of an early loosening had a high specificity (85%) but a low sensitivity (22%).
Conclusion
The conventional MSIS classification had a high diagnostic accuracy. The new MSIS classification offered only minor, non significant increase of this accuracy. As the new classification involves several additional biological assays, these results might question the cost-effectiveness of the new classification. The presence of an early loosening might be an interesting additional criterion at no additional cost.
Knee
Bones
Osteoarthritis
Total Joint Replacement
Infection

### 19333 Long term results of Collagen Meniscus Implant (CMI) an analysis of 156 cases at mean 11 years of follow-up

Stefano Zaffagnini
Gian Andrea Lucidi
Alberto Grassi
Stefano Di Paolo Eng
Piero Agostinone
Giacomo Dal Fabbro
Luca Macchiarola
Nicola Pizza
Stefano Zaffagnini
Italy
Summary
The collagen meniscus implant provide a safe and durable option for the treatment of partial meniscus defects.
Data
Background
The collagen meniscus implant (CMI) was developed to treat patients with the clinical condition of post-meniscectomy syndrome. Particularly in the presence of a partial meniscal defects. The aim the study was to identify predictors of surgical failure after CMI implant a long term follow-up.
Methods
A database search from a single center was conducted in order to identify all the CMI implanted from at a minimum 5 years of follow-up. Surgical failure was defined as partial or total scaffold removal, conversion to a meniscal transplant or unicompartmental/total knee arthroplasty. A logistic regression was performed by using sex, BMI, age at surgery, CMI laterality, Outerbridge grade (0-II vs III-IV), combined versus isolated procedure and “salvage procedure” (defined as Outerbridge grade III and an associated procedure to the CMI implant) as independent variables. Survival analysis was performed with Kaplan-Meier curve.
Results
156 patients (84%) with a mean age at surgery of 42.0 ± 11.1 were included in the final analysis at an average follow-up of 10.9 ± 4.3 years. The overall survival rate from surgical failure was 87.8%. When further evaluating the different subgroups of patients, an Outerbridge grade of III-IV (HR 3.8; P =.004), and lateral scaffold (HR, 3.2; P= .048) were identified as risk factors Finally, 42 patients (26.9%) were considered either a surgical or clinical failure. Risk factors were: an Outerbridge grade of III-IV (odds ratio [OR], 3.1; P =.000), and time from meniscectomy to scaffold greater than 10 years (OR, 2.7; P = .042).
Conclusion
The CMI showed a high surgical survival rate at a long-term follow-up. Lateral CMI, higher grade of cartilage degeneration and CMI implanted as a salvage procedure were found to be predictors of surgical failure. The results of this study are useful in the clinical setting to extimate the risk of failure and set patient‘s expectation.
Knee
Allograft
Arthritis
Meniscus
Arthroscopy
Biologics
Cartilage
Implant
Lateral
Medial
Osteoarthritis
Outcome Studies

### 19290 Bone bruise pattern and mechanism of Anterior Cruciate Ligament (ACL) injury in professional footballers: correlation between MRI and video-analysis

Pieter D’Hooghe1
Alberto Grassi2
Francesco Della Villa2
Khalid Alkhelaifi1
Emmanouil Papakostas1
Stefano Zaffagnini2
Raouf Rekik1
1Qatar
2Italy
Summary
A characteristic and well-defined Bone Bruise pattern in both tibia and femur was identified in professional footballers’ ACL injuries (without direct contact and in single-leg loading) while pivoting and trying to perform a sudden change of direction.
Data
Introduction
The presence of Bone Bruises (BB), especially in the lateral compartment of the knee, is common finding in the context of Anterior Cruciate Ligament (ACL) injury. However, different patterns has been described and a precise correlation with mechanism of ACL injury has never been determined with precision.
Material and Methods
Fifteen professional football (soccer) players that sustained ACL injury while playing during an official match of First League Championship were included in the study. The video of injury was obtained from the Television broadcast. Knee Magnetic Resonance (MRI) was obtained within 7 days from the injury. BB and meniscal lesions were analyzed on MRI, while a video-analysis of mechanisms of ACL injury and injury dynamic were assessed from the videos.
Results
The most common pattern of BB (Fig A,B), present in 8 cases (53%) was a femoral BB >5 mm in the central portion of the lateral femoral condyle and in the posterior portion of the lateral tibial plateau. In all these cases, the injury occurred with single-leg load during a pivoting maneuver while changing direction during pressing (33%), dribbling (7%), goalkeeping (7%) or in response of being being tackled on the upper body (7%). All these injuries occurred without direct contact, high horizontal speed and with abduced hip. Other patterns (Fig. C) included BB only in tibia (20%), tibia and femur BB <5 mm (7%) or no BB (20%). In these cases, injury occurred due to direct contact (20%), recovery balance after kicking (13%) or jumping (7%), and while tackling (7%).
Conclusions
A characteristic and well-defined Bone Bruise pattern in both tibia and femur was identified in professional footballers’ ACL injuries (without direct contact and in single-leg loading) while pivoting and trying to perform a sudden change of direction.
Orthopaedic Sports Medicine
Instability
Repair/Reconstruction
Sport Specific Injuries
ACL
Cartilage
Cartilage Injuries
Knee
Ligaments
MRI
Professional Athletes/Olympians
Sport Specific Population

### 19368 Good subjective outcome and low risk of revision surgery with a novel customized metal implant for focal femoral chondral lesions at a minimum of five years follow-up

Anders Stalman
David Roberts
Magnus Hogstrom
Sweden
Summary
Good subjective outcome and low risk of progression of degenerative changes and need for subsequent surgery were seen at mid-term follow-up with a customized focal knee resurfacing implant.
Data
Focal prosthetic inlay resurfacing has been proposed as a bridge between biological treatment and conventional joint arthroplasty. Promising short-term outcome is described but a high rate of revision to knee arthroplasty has been reported at mid-term follow-up It has been suggested that a more accurate implant positioning would enhance implant survival. A customized prosthesis and guide system was designed to precisely fit the cartilage defect in location and size has the potential to improve implant positioning and thereby avoid damage to the opposing cartilage. We hypothesize that good subjective outcome is preserved and that risk of osteoarthritis development and need for revision to knee arthroplasty is low at a minimum 5-year follow-up.
Methods
Ten patients, focal chondral femoral injury and previous failed biological treatment. Surgery with a customized Cr-Co femoral condyle implant. Minimum 5-year follow-up with clinical and radiological examination. Subjective outcome, KOOS. Data on re-surgery.
Results
Mean age at surgery 53 years. Mean 75 months follow-up (range 60–86 months). Two patients experienced limitation in range of motion. In one patient standing weight-bearing showed OA, Ahlbäck 1 at 84 months. Significant improvement in KOOS subscores pain (60–85), ADL (66–91), Sports (23–48), QoL (28–55) compared to pre-op. Tegner score from 3 to 4.
Conclusion
Good subjective outcome and low risk of progression of degenerative changes and need for subsequent surgery were seen at mid-term follow-up with this customized focal knee resurfacing implant.
Knee
Arthroplasty
Cartilage
Implant
Outcome Studies

### 19334 Xenograft for anterior cruciate ligament reconstruction was associated with high graft processing infection

Giulio Maria Marcheggiani Muccioli1
Willem M van der Merwe2
Giulio Maria Marcheggiani Muccioli1
Martin Lind3
Peter Faunoe3
Kees van Egmond4
Stefano Zaffagnini1
Maurilio Marcacci1
Ramon Cugat Bertomeu5
Rene E Verdonk6
Ernique Ibanez5
1Italy
2South Africa
3Denmark
4Netherlands
5Spain
6Belgium
Summary
High infection rate (20.6%) was reported after ACL reconstruction (ACLR) with xenograft. Improvements in future studies using xenografts are needed, otherwise xenograft should not be used in ACLR.
Data
Introduction
The purpose of this study was to evaluate clinical ad radiological outcomes of anterior cruciate ligament (ACL) reconstruction with an immunochemically modified porcine patellar tendon xenograft controlled against human Achilles tendon allograft at 24-month minimum follow-up.
Methods
66 patients undergoing arthroscopic ACL reconstruction were randomized into 2 groups: 34 allografts and 32 xenografts treated to attenuate the host immune response. Follow-up was 24-month minimum. Anterior knee stability was measured as KT-1000 side-to-side laxity difference (respect to the contralateral healthy knee). Functional performance was assessed by one-legged hop test. Objective manual pivot-shift test and subjective (IKDC, Tegner and SF-36) outcomes were collected. MRI and standard X-Ray were performed.
Results
61 subjects (32 allograft, 29 xenograft) were evaluated at 12 and 24 months. Six of the subjects in xenograft group (20.6%) got an infection attributed to a water-based pathogen graft contamination in processing. Intention-to-treat analysis (using the last observation carried forward imputation method) revealed higher KT-1000 laxity in xenograft group at 24-month follow-up (P = .042). Also pivot-shift was higher in xenograft group at 12-month (P = .015) and 24-month follow-up (P = .038). Per-protocol analysis (missing/contaminated subjects excluded) did not revealed clinical differences between groups. Tibial tunnel widening in the allograft group was low, whereas xenograft tunnel widening was within the expected range of 20–35% as reported in the literature. No immunological reactivity was associated to xenograft group.
Discussion and Conclusion
High infection rate (20.6%) was reported in xenograft group. Both groups of patients achieved comparable clinical outcomes if missing/contaminated subjects are excluded. Improved harvesting/processing treatments in future studies using xenografts for ACL reconstruction are needed to reduce infection rate, otherwise xenograft should not be used in ACL reconstruction. Level of evidence: multicenter and double-blinded Randomized Controlled Clinical Trial, Level I.
Knee
ACL
Ligaments
Sprain
Transplantation
MRI
Outcome Studies
X-ray

### 19295 Clinical results of extracorporeal shock wave therapy for olecranon stress fracture in baseball players

Hiroyuki Sugaya
Norimasa Takahashi
Keisuke Matsuki
Morihito Tokai
Takeshi Morioka
Yusuke Ueda
Shota Hoshika
Japan
Summary
Extracorporeal Shock Wave Therapy is a safe and viable option for an early return to play baseball, for the treatment of an olecranon stress fracture, and a persistence of the olecranon physis.
Data
Introduction
An olecranon stress fracture and a persistence of the olecranon physis are seen in adolescent baseball players associated with valgus extension overload. They were often unable to return to sports early, however, because of cases of delayed union or refracture. And many doctors suggested the necessity of surgery. Extracorporeal Shock Wave Therapy (ESWT) has been reported to be effective in the treatment of stress fracture. However, there are no studies regarding ESWT exclusively for olecranon stress fracture in baseball players. The purpose of this study is to report clinical results of olecranon fracture in baseball players that were treated with ESWT.
Methods
13 baseball players (13 elbows) who were treated with ESWT were included in this study. All subjects were competitive level athletes, and all patients were male. All affected sides was their throwing side. The mean age was 15 (13–21). Exclusion criteria was olecranon tip fracture cases. The mean follow up period was 9 months. They played in the following positions: pitchers (8), outfielders (3), catcher (1) and infielder (1). Each subject received 1 to 2 times ESWT. Maximum energy flux density (EFD) ranged from 0.07 to 0.36mJ/mm2. At each session, subjects received 3000 to 5000 shocks. All of them received physiotherapy focusing on eccentric loading exercises along with ESWT. Our primary assessment was to analyze clinical results, including, return to competition, recurrence, period between presentation and ESWT. Our secondary assessment was to analyze the period until bone union and bone union rate between olecranon stress fracture cases and persistence of the olecranon physis cases in plane radiographs.
Results
All patients returned to competition. In the season cases(8 patients), their return to competition time is 6.1 weeks on average (4–9). One patient returned to sport as the infielder from the pitcher. One of them had recurrence of symptoms 3 months after taking ESWT, but he returned to competition after the second ESWT and no recurrence. The complete competition return rate was 86%. In the off-season cases (5 patients), those return to competition time is at 16.4 weeks on average (8–28). Two of them had recurrence of symptoms 3 months and 52 months after taking ESWT, but they returned to competition after the second ESWT and no recurrence. The complete competition return rate was 100%. The mean period between presentation and initiation of ESWT was 2.9 months (09) in the season, 4.4 months (2-7) in the off-season. In the olecranon stress fracture cases, bone union was seen in 6 cases, improvement was seen in 2 cases, and no change was seen in 1 case. In persistence of the olecranon physis cases, closed physis was seen in 2 cases, improvement was seen in 2 cases, no change was 1 case. The mean period until bone union was 8.6 months (2.5-20) in the olecranon stress fracture cases and 19.8 month (10- 27) in persistence of the olecranon physis cases.
Conclusion
This study indicates ESWT is a safe and viable option for the treatment of an olecranon stress fracture and a persistence of the olecranon physis in adolescent baseball players. ESWT for those patients was effective for pain relief and shortened the period of return to sports. It also indicates that bone union of the olecranon stress fracture was promoted after several sessions of ESWT, and that closing of the olecranon physis might not be affected after several sessions of ESWT.
Elbow/Wrist/Hand
Bones
CT-Scan
Impingement
Medical Aspects
MRI
Outcome Studies
Physical Examination
Posterior Pain
Sport Specific Injuries
Sport Specific Population
Ultrasound
X-ray

### 19209 Greater postoperative valgus loose gap at 90° of flexion improves patient reported outcome measurement in anatomical bi-cruciate retaining total knee arthroplasty

Takao Kaneko
Yuta Mochizuki
Shinya Toyoda
Hiroyasu Ikegami
Japan
Summary
Anatomical bi-cruciate retaining total knee arthroplasty.
Data
Background
The purpose of the present study is to measure the intraoperative joint gap using tensor device and pre- and, postoperative variation of coronal stability at 0, 30 and 90° of flexion using stress radiograph and identify whether these factors influence patient reported outcome measurement (PROM).
Methods
53 knees with preoperative varus osteoarthritis of the knee were treated with anatomical BCR TKA with oblique 3°angle femorotibial joint line (Journey II XR; Smith& Nephew. Inc. Memphis, TN, USA). The intraoperative joint gap (medial, lateral and varus-valgus) using a tensor device and varus-valgus gap angle were measured using stress radiographs. PROM was also evaluated at 1.5 years postoperatively.
Results
There was no significant difference between pre- and postoperative flexion angle. Intraoperative medial laxity rather than medial tightness from full extension to 140° of flexion angle played an important role in influencing postoperative function of patellofemoral joint. Intraoperative varus laxity at full extension improved postoperative symptom in 2011 Knee Society Score (2011 KSS), while greater postoperative lateral stability at 30 and 90° of flexion with the varus stress test was found to contribute to the patient expectation in 2011 KSS. Greater postoperative valgus laxity at 90° of flexion with the valgus stress test improved the patient expectation and satisfaction in 2011 KSS, stiffness in WOMAC score and FJS-12.
Conclusion
The findings in the present study suggest that the intraoperative joint gap after implantation is not rectangular but trapezoidal gap and greater postoperative varus stability and valgus laxity at 90° of flexion improved patient reported outcome measurement in anatomical BCR TKA.
Knee
Arthroplasty
Bones
Compartment Pressure
X-ray

### 19223 The latarjet procedure in competitive athletes younger than 20 years old with a significant glenoid bone loss

Luciano A Rossi
Ignacio Tanoira
Ignacio Pasqualini
Maximiliano Ranalletta
Argentina
Summary
The Latarjet procedure in competitive athletes younger than 20 years old with a significant glenoid bone loss.
Data
Purpose
To analyze return to sports, functional outcomes, and complications following the Latarjet procedure in competitive athletes younger than 20 years old with a significant glenoid bone loss.
Methods
Between 2010 and 2017 60 competitive athletes younger than 20 years old with a significant glenoid bone loss were operated with the Latarjet procedure. Return to sports, range of motion (ROM), the Rowe and the ASOSS score were used to assess functional outcomes. Complications and bone consolidation were also evaluated.
Results
The mean follow- up was 58 months and the mean age was 16.3 years. Overall, 93% were able to return to sports and 84% returned at the same level. The Rowe and ASOSS scores showed statistical improvement after operation (P < .001). The total complication rate was 22% and the revision rate was 1.6% The recurrence rate was 3.3%. The bone block healed in 93% of the cases.
Conclusions
In competitive athletes younger than 20 years old with a significant glenoid bone loss, the Latarjet procedure resulted in excellent functional outcomes, with most of the patients returning to sports and at the same level they had before injury with a low rate of recurrences. However, this procedure is associated with a significant rate of complications and should preferably be performed by experienced surgeons.
Shoulder
Autograft
Dislocation
Glenohumeral
Capsuloligamentous Complex
Sport Specific Injuries

### 19224 High variability in functional outcomes and recurrences between contact/collision sports after arthroscopic bankart repair. A comparative study of 351 patients with a minimum 3-year follow-up

Luciano A Rossi
Ignacio Tanoira
Tomás David Gorodischer
Ignacio Pasqualini
Maximiliano Ranalletta
Argentina
Summary
High Variability in Functional Outcomes and Recurrences Between Contact/Collision Sports after Arthroscopic Bankart Repair. A Comparative Study of 351 patients With a Minimum 3-Year Follow-Up
Data
Purpose
To compare return to sports, functional outcomes and complications of a consecutive series of contact athletes with anterior glenohumeral instability treated with isolated arthroscopic Bankart repair for isolated anterior instability
Materials and Methods
Between January 2008 and December 2016, 351 competitive athletes who participated in contact or collision sports underwent isolated arthroscopic Bankart repair at our institution (rugby n=105, soccer n=90, martial arts n=36 boxing n=28, field hockey n=30, handball n= 31 basketball n=31). Return to sports, the Rowe score, and the ASOSS score were used to assess functional outcomes. Complications were also evaluated.
Results
The mean follow-up period was 66.7 months (range, 36–148 months) and the mean age of the 351 patients was 21.3 years (range, 17–30 years).Overall, 309 patients (88%) were able to return to sports, and 284 (81%) returned at the same level as before the injury. The mean time to return to sports was 5.3 months. The rate of return to sports, the level achieved by the patients and time to return to sports varied significantly between sports. The Rowe, and ASOSS scores showed statistical improvement after operation (P < .001). The ASOSS score varied significantly between sports (P < .001). There were 40 recurrences (11.3%), 7 complications (2%) and 21 patients (6%) underwent revisión surgery. There was a significant difference in the rate of recurrences and revisions between the different contact sports
Conclusions
In athletes with glenohumeral instability who underwent isolated arthroscopic Bankart repair for isolated anterior instability, there is great variability in the rate of return to sport at the same level, in shoulder performance after returning to competition, and in the postoperative recurrence rates. Due to the high variability found in our study, results after arthroscopic Bankart repair in contact athletes should not be reported globally by including the different sports under the “collision or contact sports” label.
Shoulder
Arthroscopy
Dislocation
Glenohumeral
Capsuloligamentous Complex
Labrum
Sport Specific Injuries

### 19206 Risk factors for grade 3 pivot shift in acute ACL-injured knees

Edoardo Monaco2
Edoardo Gaj2
Valerio Andreozzi2
Alessandro Annibaldi2
Alessandro Carrozzo2
Thais Dutra Vieira3
Bertrand Sonnery-Cottet4
Andrea Ferretti2
1USA
2Italy
3Brazil
4France
Summary
Injury to the anterolateral structures was identified to be the most important risk factor for grade 3 pivot shift in acute ACL-injured knees when previously described osseous and soft-tissue parameters were comprehensively accounted for in an adequately powered study.
Data
Introduction
Pre-operative high-grade pivot shift (PS) has been reported to be associated with higher rates of anterior cruciate ligament (ACL) failure, persistent instability and inferior patient reported outcomes. The aetiology of a high-grade PS is multifactorial and numerous factors have been suggested to be responsible. However, the literature is conflicting. In part, this is due to numerous underpowered studies that also fail to account for known risk factors. The aim of this study was to determine risk factors for high-grade pivot shift with a particular emphasis on addressing the limitations of previous studies, therefore including a comprehensive evaluation of both soft-tissue and osseous parameters in an adequately powered study.
Methods
A prospective evaluation of consecutive patients undergoing acute ACL reconstruction (within 10 days of injury) was undertaken. An a priori sample size calculation was performed in order to ensure recruitment of an adequate number of patients. At the time of surgery, the pivot shift test was performed in a standardized manner and graded (International Knee Documentation Criteria). Details regarding patient and injury characteristics were recorded, as were details of injuries to soft-tissues structures including the menisci, anterolateral structures (ALS), medial collateral ligament (other multi-ligament injuries excluded) and articular cartilage. Osseous parameters (tibial slope and condylar ratios) were evaluated using established magnetic resonance imaging (MRI) protocols. A multivariate logistic regression with Penalized Maximum Likelihood was used to identified risk factors associated with grade 3 pivot shift. Factors initially considered were those selected as statistically significant at the 25% threshold, or of previously reported clinical interest. A stepwise descending strategy was applied from the initial full model to determine the most parsimonious one.
Results
200 consecutive patients with a mean age of 28.3 ± 9.8 years were included in the study. 67.5% of patients were male. 35 (17.5%) of patients had a high grade (grade 3) pivot shift and 165 (82.5%) had a low-grade pivot shift (grades 1 and 2). Univariate analyses demonstrated that injury to the ALS was the only significant risk factor for high grade pivot shift. This finding remained true when factors reaching the 25% threshold or of previously reported clinical interest were included in multivariate analysis (OR 13.49; 95% CI, 1.80–1725.53). Although previous studies have suggested that there are other important risk factors for high grade pivot shift, this did not hold true in the current study.
Conclusions
This comprehensive evaluation of soft-tissue and osseous factors has identified that injury to the ALS is the most important risk factor for grade 3 pivot shift in acute ACL-injured knees.
Knee
ACL
Instability
Ligaments
Repair/Reconstruction
Arthroscopy
Biomechanics
Bones
Capsuloligamentous Complex
Cartilage
Cartilage Injuries
Evidence Based Medicine
Lateral
Medial
Meniscus
MRI
Physical Examination
Professional Athletes/Olympians
Tears
X-ray

### 19216 Risk of conversion to arthroplasty following hip arthroscopy: validation of a published risk score using an independent, prospectively collected database

Mario Hevesi
Devin Leland
Philip Joseph Rosinsky
Ajay C Lall
Benjamin G Domb
David E Hartigan
Bruce A Levy
Aaron J Krych
USA
Summary
This external validation study supports that the THA risk score proposed by Redmond et al. accurately predicts hip arthroscopy patients converting to subsequent arthroplasty, with satisfactory discriminatory, Receiver-Operator Curve (ROC), and Brier score calibration characteristics.
Data
Background
Hip arthroscopy is rapidly advancing and increasingly commonly performed. The most common surgery following arthroscopy is total hip arthroplasty (THA), which unfortunately occurs within 2 years of arthroscopy in up to 10% of patients. Predictive models for conversion to THA such as that proposed by Redmond et al. have potentially substantial value in preoperative counseling and decreasing early arthroscopy failures, however, these models need to be externally validated to demonstrate broad applicability.
Purpose
To utilize an independent, prospectively collected database to externally validate a previously published risk calculator by determining its accuracy in predicting conversion of hip arthroscopy to THA at minimum 2-year follow-up. Study Design: Cohort Study, Level of Evidence, 3.
Methods
Hip arthroscopies performed at a single center November 2015–March 2017 were reviewed. Patients were assessed pre/intra-operatively for components of the THA risk score studied, namely age, modified Harris Hip Score (mHHS), lateral center edge angle, revision procedure, femoral version, and femoral/acetabular Outerbridge score, and followed for a minimum of 2 years. Conversion to THA was determined along with the risk score’s receiver-operator curve (ROC) and Brier score calibration characteristics.
Results
187 patients (43M, 144F, age: 36.0 ± 12.4 years) underwent hip arthroscopy and were followed for mean of 2.9 ± 0.85 years (Range: 2.0–5.5), with 13 patients (7%) converting to THA at a mean of 1.6 ± 0.9 years. Patients who converted to THA had a mean predicted arthroplasty risk of 22.6 ± 12.0% compared to patients who remained arthroplasty free with a predicted risk of 4.6 ± 5.3% (p<0.01). The Brier score for the calculator was 0.04 (p=0.53), which was not statistically different from ideal calibration, and the calculator demonstrated a satisfactory AUC of 0.894 (p<0.001).
Conclusion
This external validation study supports that the THA risk score proposed by Redmond et al. accurately predicts hip arthroscopy patients converting to subsequent arthroplasty, with satisfactory discriminatory, ROC, and Brier score calibration characteristics. These findings are important in that they provide surgeons with validated tools to identify patients at greatest risk for failure following hip arthroscopy and assist in patient counseling and decision making.
Hip/Groin/Thigh
Arthroscopy
Cartilage
Osteoarthritis
Arthritis
Arthroplasty
Labrum
Labrum Tears
Labrum Treatment
Outcome Studies

### 19289 Prospective clinical feasibility study of a PLLA scaffold In primary ACL reconstruction with 5-year follow-up

Kees van Egmond1
Robert A Arciero2
Reinoud W Brouwer1
Robert A Stanton2
1Netherlands
2USA
Summary
Recently, a bioresorbable, acellular, poly(L-lactic acid) (PLLA) scaffold was developed for ACL reconstruction, composed of three-dimensionally braided polymeric microfilaments to guide cellular infiltration and growth of new ligament tissue. Therefore, the object of this study was to assess the safety and feasibility of the PLLA scaffold, for primary ACL reconstruction in a prospective, consecu
Data
Introduction
Anterior cruciate ligament (ACL) rupture is one of the most serious sports-related injuries, and nearly 200,000 ACL reconstructions are performed each year in the US. Surgical reconstruction using an autograft remains the gold standard treatment option, but graft selection remains debated and outcomes are affected by the associated donor-site morbidity. The only alternative, allograft, is prone to higher rates of failure, and is inherently limited in quality and availability. To date, a demand remains for a safe, ‘off-the-shelf’ implant for ACL reconstruction, and tissue engineering is one approach that can provide a regenerative solution. Recently, a bioresorbable, acellular, poly(L-lactic acid) (PLLA) scaffold was developed for ACL reconstruction, composed of three-dimensionally braided polymeric microfilaments to guide cellular infiltration and growth of new ligament tissue. Therefore, the object of this study was to assess the safety and feasibility of the PLLA scaffold, for primary ACL reconstruction in a prospective, consecutive, clinical study.
Methods
Fifteen patients (ages 18 to 46 years old) with ACL ruptures were implanted (<18 weeks post-injury) with a PLLA scaffold for ACL reconstruction. The primary endpoint for the study was defined as the absence of graft failure or revision ACL surgery at one year. The study was performed in a highly active patient cohort, with 11 of 15 patients reporting a pre-injury Tegner score of 9 out of 10. Secondary endpoints were determined by safety rates per complications, subjective patient-reported outcomes (2000 IKDC scale, KOOS pain, Tegner, and Lysholm scores), clinical function (Lachman test, KT-1000, pivot shift, anterior drawer, and single leg hop test), and imaging measures (radiographic, MRI, and CT). In the case of graft failure, arthroscopic confirmation was performed prior to or on the same day as revision surgery, and biopsies were taken from the intra-articular region during revision surgery and processed for histological and molecular weight analyses.
Results
No infections, allergic reactions, or synovitis were reported indicating safety of the implant. Patient-reported IKDC scores (and additional patient-reported outcome measures, Table 1) showed progressive improvement at 6 and 12 months compared to baseline values. Physician-reported clinical evaluations of knee function showed little to no laxity or knee instability at the one year follow-up. However, review of MRI at 6 and 12 months showed a hyper-intense signal indicative of (what?, please complete sentence (Figure 1A). Five graft ruptures occurred between 12 and 36 months follow-up, with one additional rupture at 44 months in a total follow-up of 5 years. Five of the re-ruptures occurred while subjects were playing soccer. One re rupture occurred with a minor trauma. Histological analysis of graft biopsies obtained during revision surgeries revealed a fully cellularized scaffold containing a peripheral synovial cell layer, neovascularization, and robust extracellular matrix. A chronic inflammatory response, marked by foreign body giant cells, was observed adjacent to remnant PLLA (Figure 1A). For the remaining patients, MRI revealed thinning of the ligament and regional hyper-intensity that persisted through 18 and 24 months (Figure 1B). Although 10 individuals without failure at 36 months follow-up continued to report normal ACL function, IKDC scores decreased at 18 months and plateaued through 36 months follow-up though neither were statistically significant. (Table 1).
Discussion and Conclusion
The first-in-man study of a PLLA scaffold for primary reconstruction of the ACL demonstrated the feasibility of an acellular tissue-engineered scaffold; however, tissue regeneration was inconsistent in this 15-patient cohort, resulting in clinically unacceptable failure rates in this limited study. Six patients experienced ruptures between 12 and 60 months, suggesting insufficient load-bearing capacity of the new ligament tissue in the presence of a weakening scaffold. These findings suggest that further innovation is required to optimize scaffold properties in order to achieve long-term clinical efficacy with a bioresorbable implant for ACL reconstruction.
Knee
ACL
Biologics
Instability
Ligaments
MRI
Physical Examination
Sport Specific Injuries
X-ray

### 19360 Goutallier classification reliability may be impacted by the size of the rotators cuff tear

Jason A Old2
Peter B MacDonald2
Sheila McRae1
Urszula Smyczynska2
James Koenig2
Graeme Matthewson2
Jarret M Woodmass2
Fleur Verhulst3
Yiyang Zhang2
Laurie Stillwater2
1Poland
3Netherlands
Summary
Goutallier classification may need adjustments once the gross cuff tear retraction is present.
Data
Introduction
Goutallier classification is widely used to describe fatty infiltration within a rotator cuff muscle belly. Initially developed based on axial CT images, the grading system has been extrapolated to magnetic resonance imaging (MRI) over time. Goutallier classification based on MRI is widespread, but no one has yet studied if its reliability can be deteriorated by the size of the cuff retraction. The aim of our study was to evaluate whether the Goutallier grading system should be adjusted to the cuff tear size or if it is reliable regardless the amount of retraction.
Methods
This was a prospective observational study. MRIs of 81 patients reflecting a range of tear sizes were compiled and 3 parasagittal cuts from each series were extracted and de-identified (total 243 images). The image based on the coronal view with the greatest supraspinatus tendon retraction was used for tear-size classification according to Cofield classification. The most lateral cut in which the scapular spine is still attached to the scapular body represented the traditionally used ‘baseline” cut for Goutallier classification. Two additional cuts were obtained 3 and 6 slices medially from the first. Nine clinicians (3 fellowship trained upper extremity surgeons, 2 upper extremity fellows, 2 orthopedic residents and 2 fellowship trained musculoskeletal radiologists) assigned Goutallier classifications to each of the four RC muscles based on the three MRI cuts. Evaluation of all images was repeated 3 times with a 7-day gap between each session and images re-randomized for each session. A threshold of Krippendorff’s alpha of 0.8 was set a priori and reviewers achieving 0.8 or higher were included in further analysis with the purpose of revealing the impact of size of cuff tear and slice on Goutallier grade. Kruskall-Wallis was used to determine the impact of expertise on intra-rater reliability.
Results
Five of 9 clinicians achieved a level of 0.8 or higher reflecting high intra-rater reliability. Reliability was not significantly associated with expertise (p=0.3089). Based on only the raters with high intra-rater reliability, there was a significant difference in Goutallier grade between slices in supraspinatus (p=0.007), infraspinatus (p<0.001), and subscapularis (p=0.0193), but not teres major (p=0.4227). The tendency was to give the lower grade for same muscles, in more medial MRI cuts. Comclusion: Goutallier classification is influenced by the slice reviewed, the size of the tear, and the muscle being evaluated. A systematic approach to grading based on MRI needs to be established with adequate training. Choosing the right MRI image can be crucial for accurate diagnosis and treatment planning, especially as torn rotators cuff tendons tend to retract over the time and retraction is a well-known risk factor for a non-successful repair.
Shoulder
Female Athletes
Glenohumeral
Infraespinatus
MRI
Muscle
Professional Athletes/Olympians
Subescapular
Supraespinatus
Teres Minor

### 19322 Negative effects of delayed anterior cruciate ligament reconstruction on associated injuries and knee laxity

Riccardo Cristiani
Per-Mats Janarv
Bjorn Engstrom
Gunnar Edman
Anders Stalman
Sweden
Summary
To reduce meniscus loss and the risk of jeopardizing knee laxity, ACLR should be performed within 6 months after the injury.
Data
Background
No reliable tools are able to predict which patients will become “copers” following a trial of non-operative treatment after an ACL injury. Some authors suggest a strategy of rehabilitation with the option of delayed reconstruction, whereas others recommend early reconstruction. A delay in ACLR could increase intra-articular knee shear forces. Questions remain about the safe time interval from injury to ACLR in reducing the prevalence of concomitant intra-articular injuries and only a few studies have evaluated the effect of delayed ACLR on meniscus repair rates. Variables such as age, gender and BMI have also been suggested as factors potentially correlated with the development of intra-articular injuries and the likelihood of meniscus repair. Finally, the effect of these demographic characteristics and the potential benefits of early ACLR on knee laxity are poorly studied.
Purpose
To determine the association between a delay in ACLR, age, gender, BMI and cartilage injuries, meniscus injuries, meniscus repair, and abnormal pre-reconstruction laxity.
Methods
A total of 3,976 patients who underwent primary ACLR at our institution from 2005 to 2017, with no associated ligament injuries, were included. Logistic regression analyses were used to evaluate whether delay in ACLR, age, gender and BMI were risk factors for cartilage and meniscus injuries, meniscus repair, and abnormal (side-to-side difference >5 mm) pre-reconstruction laxity.
Results
The risk of cartilage injury increased with a delay in ACLR (12–24 months: odds ratio[OR], 1.20; 95% confidence intervals[CI], 1.05–1.29; P=.005; and >24 months: OR,1.20; 95% CI, 1.11–1.30; P<.001) and age =>30 years (OR, 2.27; 95% CI, 1.98–2.60; P<.001). The risk of medial meniscus (MM) injury increased with a delay in ACLR (12–24 months: OR, 1.20; 95% CI, 1.07–1.29; P=.001; and >24 months: OR,1.22; 95% CI, 1.13–1.30; P<.001), male gender (OR, 1.16; 95% CI, 1.04–1.30; P=.04) and age =>30 years (OR, 1.20; 95% CI, 1.04–1.33; P=.008). The risk of lateral meniscus (LM) injury decreased with a delay in ACLR of >3 months and age =>30 years (OR, 0.75; 95% CI, 0.66–0.85; P<.001), whereas it increased with male gender (OR,1.32; 95% CI,1.22–1.41; P <.001). MM repairs relative to MM injury decreased with a delay in ACLR (6–12 months: OR, 0.70; 95% CI, 0.54–0.92; P=.01; 12–24 months: OR, 0.69; 95% CI, 0.57–0.85; P<.001; >24 months: OR, 0.61; 95% CI, 0.52–0.72; P<.001) and age =>30 years (OR, 0.60; 95% CI, 0.48–0.74; P<.001). LM repairs relative to LM injury only decreased with age =>30 years (OR, 0.34; 95% CI, 0.26–0.45; P <.001). The risk of having abnormal knee laxity increased with a delay in ACLR of >6 months and MM injury (OR, 1.52; 95% CI, 1.16–1.97; P=.002), whereas it decreased with a BMI of =>25 kg/m2 (OR, 0.68; 95% CI, 0.52–0.89; P=.006).
Conclusions
A delay in ACLR of >12 months increased the risk of cartilage and MM injuries, while a delay of >6 months increased the risk of abnormal pre-reconstruction laxity and reduced the likelihood of MM repair. To reduce meniscus loss and the risk of jeopardizing knee laxity, ACLR should be performed within 6 months after the injury.
Knee
ACL
Arthroscopy
Instability
Ligaments
Biomechanics
Cartilage
Cartilage Injuries
Epidemiology
Lateral
Medial
Meniscus

### 19313 Changes in muscle strength and hop performance after ACL reconstruction. A randomized controlled trial comparing patellar tendon and hamstring tendon autografts with standard or accelerated rehabilitation

Riccardo Cristiani
PT Christina Mikkelsen
Peter Olov Wange
Daniel Olsson
Anders Stalman
Bjorn Engstrom
Sweden
Summary
Asymmetries in muscle strength and hop performance are persistent even 24 months after ACLR performed with either of the 2 grafts. Rehabilitation protocols should be implemented and more time needs to be spent on muscle strength rehabilitation. The choice between BPTB and HT grafts strongly affects the pattern of recovery of muscle strength.
Data
Background
The most commonly used autografts for anterior cruciate ligament (ACLR) are the hamstring tendons (HT) and the bone-patellar tendon-bone (BPTB). However, questions remain about how patients with either an HT or a BPTB autograft recover knee muscle strength postoperatively. Contrasting results have been reported in randomized studies comparing the two autografts at postoperative follow-ups ranging from 3 to 24 months after ACLR. Moreover, there is a lack of studies comparing the effects on the recovery of muscle strength and hop performance of an accelerated or a standard rehabilitation protocol for both autografts at several follow-ups after ACLR.
Purpose
To evaluate and compare changes in quadriceps and hamstring strength and single-leg-hop (SLH) test performance over the first 24 postoperative months in patients who underwent ACLR with BPTB or HT autografts and followed either a standard or an accelerated rehabilitation protocol.
Methods
A total of 160 patients undergoing ACLR were randomized in 4 groups depending on the graft that was used and the rehabilitation protocol (40 BPTB/standard rehab, 40 BPTB/accelerated rehab, 40 HT/standard rehab, 40 HT/accelerated rehab). Isokinetic concentric quadriceps and hamstring strength at 90°/s and the SLH test performance were assessed preoperatively and 4,6,8,12 and 24 months postoperatively. The results were reported as the limb symmetry index (LSI) at the same time point. Linear mixed models were used to compare the groups at the different time points throughout the follow-up.
Results
An average quadriceps strength LSI of 78.4% was found preoperatively. After ACLR, the LSI first decreased at 4 months and then increased from 6 to 24 months, reaching an overall value of 92.7% at the latest follow-up. The BPTB group showed a significantly decreased LSI at 4, 6, 8 and 12 months compared with the HT group. No significant differences between the graft groups were found at 24 months. An average hamstring strength LSI of 84.6% was found preoperatively. After ACLR, the LSI increased from 4 to 24 months in the BTPB group. In the HT group, the LSI first decreased at 4 months and then increased from 6 to 24 months. An LSI of 97.1% and 89.1% was found at the latest follow-up for the BPTB and the HT group respectively. The HT group showed a significantly decreased LSI at all follow-ups (4, 6, 8, 12 and 24 months) compared with the BPTB group. An average SLH test LSI of 81.0% was found preoperatively. After ACLR, the LSI increased from 4 to 24 months, reaching 97.6% overall at the latest follow-up. The BPTB group showed a significantly decreased LSI at 4 months postoperatively compared with the HT group. No significant differences between the graft groups were found at the other time points. No significant differences in any of the three tests were found between the standard and accelerated rehabilitation groups for either of the graft groups at any time point.
Conclusion
Muscle strength and SLH test performance recovered progressively after ACLR overall, but they did not all fully recover, as the injured leg performed on average less than 100% compared with the uninjured leg even 24 months postoperatively. After ACLR, inferior quadriceps strength and a poorer SLH test performance were found at 4, 6, 8 and 12 months and at 4 months respectively for the BTPB group compared with the HT group. Persistent, inferior hamstring strength was found at all postoperative follow-ups in the HT group. Rehabilitation, standard or accelerated, had no significant impact on the recovery of muscle strength and SLH test performance after ACLR in any of the graft groups.
Knee
ACL
Ligaments
Muscle

### 19379 Arthroscopic superior capsular reconstruction with mesh augmentation for the treatment of massive irreparable rotator cuff tears

Erica Kholinne
In-Ho Jeon
Indonesia
Republic of Korea
Summary
Arthroscopic superior capsular reconstruction is a promising option to treat irreparable rotator cuff tears in young patients. Surgical modification using polypropylene mesh augmentation to the graft material may help reduce graft failure.
Data
Background
Arthroscopic superior capsular reconstruction (ASCR) is an alternative to open surgery for irreparable chronic rotator cuff tears. This approach can provide static restraint while avoiding upward migration of the humeral head. However, graft tears and their impact on clinical outcomes following ASCR remain a debated topic.
Purpose
This study aimed to evaluate the clinical outcomes of ASCR with mesh augmentation for the treatment of irreparable rotator cuff tears (IRCTs). Study Design: Retrospective case-control study.
Methods
From 2013 to 2018, the data of 72 patients with IRCTs who underwent ASCR were retrospectively evaluated. Among them, 64 patients who met the inclusion and exclusion criteria were enrolled in this study. Fascia lata grafts augmented with a polypropylene mesh were used for 30 patients (group M) and grafts without mesh augmentation were used for 34 patients (group C). Clinical outcomes were evaluated using range of motion, the American Shoulder and Elbow Surgeons (ASES) questionnaire, and Visual Analog Scale for pain. Radiological outcomes were evaluated with based on acromiohumeral distance (AHD) and stage of rotator cuff arthropathy. The status of fatty infiltration and graft was evaluated using magnetic resonance imaging. Outcomes were assessed preoperatively and at the final follow-up.
Results
Both groups showed improvement in clinical and radiological outcomes at the final follow-up. Group M demonstrated a higher improvement in ASES score (29.1 ± 15.8) than group C (18.1 ± 15.9, p = 0.006). Forward flexion and external rotation improved in group M (40 ± 26 and 11 ± 5, respectively) and group C (28 ± 23 and 6 ± 3, respectively; p = 0.003 and 0.004, respectively). Graft healing rate was significantly higher in group M (83.3%) than in group C (58.8%, p = 0.039) and AHD was significantly higher in group M (9.1 ± 2.4 mm) than in group C (6.3 ± 1.8 mm) at the final follow-up (p = 0.001). Subgroup analysis revealed that patients with graft failure generally showed progression of fatty infiltration without improvement in the stage of rotator cuff arthropathy. Patients with intact grafts demonstrated a more substantial improvement in functional outcomes (ASES score and forward flexion motion).
Conclusion
ASCR with mesh augmentation reduces graft failure rate as to restore superior shoulder joint stability.
Shoulder
Arthroscopy
Tears
Autograft
Elderly
Glenohumeral
MRI
Outcome Studies
Supraespinoatus Tendon Injury
Tendon

### 19315 Biconcave medial tibial plateau morphology and the association with medial meniscal tear pathology

Trevor Shelton
John Ryan Taylor
Joshua Mizels
Trevor Shelton
F Alan Barber
Mark Getelman
USA
Summary
This newly established classification system for biconcave medial tibial plateaus (BMTP) will help surgeons identify and understand the Type II BMTP and provide the basis on which further research will determine the impact of tibial morphology on medial meniscal pathology and a treatment algorithm as type II BMTPs are at an increased risk of complex medial meniscus tears.
Data
Introduction
There has been limited investigation regarding the consequence of tibial plateau morphology on the meniscus. A biconcave medial tibial plateau (BMTP) has been previously described as a coronal plane ridge of the medial tibial plateau, typically aligned near the inner margin of the posterior body of the medial meniscus. Further investigation of the designated BMTP morphology demonstrated specific patterns in the topographical anatomy and shape compared to the normal, flat medial tibial plateau. However, it remains unknown whether patients with BMTP morphology are more prone to complex medial meniscus tears which could have implications on treatment. As such, the purpose of this study was to: (1) present a classification system for BMTP morphology, and (2) determine whether patients with a certain type of BMTP and more susceptible to complex medial meniscus tears.
Methods
Evaluated a 6-month consecutive series of all knee arthroscopies for BMTP morphology and meniscal tears using intraoperative video at time of surgery. Three distinct morphologies were identified. Those with a “flat” medial tibial plateau were classified as normal and served as the control group. Type I BMTP consisted of an oblique, narrow ridge of the medial tibial plateau. Type II BMTP of a transverse, wide, coronal plane ridge, separating the front two-thirds from the back of the medial tibial plateau. Demographic data, and arthroscopic knee pathology characteristics were also recorded. Intraclass correlation coefficient (ICC) was used to determine the interobserver reliability of the classification system. A Fisher’s exact test was used to determine differences in categorical data (i.e., complex medial meniscus tear) between groups while a single factor ANOVA was used to determine differences in continuous variables (i.e. age) between groups.
Results
147 consecutive knee arthroscopies were evaluated - 55 (37.4%) had a normal plateau, 43 (29.3%) had a Type I BMTP, and 49 (33.3%) had a Type II BMTP. There was excellent inter-observer reliability (kappa statistic=0.842). Those patients with Type II BMTP were three times more likely to have a complex medial meniscus tear than those with a Type I BMTP (odds ratio 3.2 [1.4, 7.6])(p=0.01) and two times more likely to have a complex medial meniscus tear compared to those with a flat plateau morphology or Type I BMTP (odds ratio 2.2 [1.1, .5])(p=0.04). There was no increased risk of a complex medial meniscus tear with a Type I BMTP compared to a flat plateau morphology (odds ratio 0.5 [0.3, 1.2])(p=0.15).
Conclusion
Biconcave medial tibial plateau is best diagnosed at the time of arthroscopy and can be reliably classified into two distinct types. Type II BMTP occur in approximately 1/3rd of patients and are at an increased risk for complex medial meniscus tear when compared to patients with Type I BMTP or flat plateau. This newly established classification system will help surgeons identify and understand the Type II BMTP and provide the basis on which further research will determine the impact of tibial morphology on medial meniscal pathology and a treatment algorithm.
Knee
Arthroscopy
Meniscus
Tears
Arthrography
Elderly
Epidemiology
Medial
MRI
Outcome Studies

### 19312 Treatment of massive irreparable rotator cuff tears without arthritis: a comparison of superior capsular reconstruction, partial rotator cuff repair, and reverse total shoulder arthroplasty

Travis Frantz
Marisa Ulrich
Joshua Scott Everhart
Andrew Mundy
Jonathan D Barlow
Grant L Jones
Gregory L Cvetanovich
Julie Bishop
USA
Summary
SCR, PR, and rTSA for massive, irreparable RCT without arthritis all significantly improved post-op strength and outcome scores with >80% patient satisfaction, but with rTSA having worse post-op ROM. For all patients, increased pre-op ER ROM and strength correlated with improved patient satisfaction, while increased AH distance correlated with improved post-op strength.
Data
Objectives
Surgical indications for massive, irreparable rotator cuff tears (RCT) without arthritis remain unclear. The purpose of this study was to compare outcomes of superior capsular reconstruction (SCR), partial rotator cuff repair (PR), and reverse total shoulder arthroplasty (rTSA) at greater than 2 years follow-up and identify any risk factors which may correlate with outcomes.
Methods
A retrospective analysis of prospectively collected data from a single tertiary academic medical center of consecutive patients undergoing surgical treatment for massive irreparable RCT without arthritis using SCR, PR (using interval slide and/or margin convergence), or rTSA from 01/01/2006 to 01/01/2018 was performed. Patients were required to be at least 18 years of age and have intra-op confirmation of a massive, irreparable, RCT without arthritis. Patient demographics and pre-op clinical findings were collected. Post-op data included complications, patient satisfaction, strength and ROM, and patient reported outcomes. Multivariate analysis was also performed.
Results
32 patients met inclusion criteria for SCR, 24 for PR, and 42 for rTSA (mean follow-up years: SCR 3.2; PR 4.0; rTSA 3.5; p=0.02). The rTSA patients were older (66.2 years; SCR - 57.3; PR - 59.0; p=0.0001) and more likely to be female (61.9%; SCR - 12.5%; PR - 25.0%; p<0.001). Intra-op evaluation demonstrated the subscapularis to be non-functional in 37.5% for SCR, 4.2% for PR, and 21.4% for rTSA (p=0.01). Pseudoparalysis was present in 18.8% of SCR, 0% of PR, and 14.3% of rTSA patients (p=0.08). All groups saw significant post-op improvement in strength and patient reported outcomes (p<0.036). SCR and rTSA demonstrated improved forward elevation ROM post-op while PR did not (p=0.96). No group experienced improvement in IR or ER ROM post-op (p>0.12). rTSA had significantly worse post-op ROM in all planes compared to SCR and PR (p<0.003 for all). There were no differences between groups in post-op strength (p>0.16) or patient reported outcomes (ASES p=0.14; VAS p=0.86; SANE p=0.61). Patients were satisfied or somewhat satisfied in 81.2% of SCR cases, 87.5% of PR, and 95.3% of rTSA (p=0.33). Three of 32 (9.4%) SCR patients required conversion to rTSA, while 3 of 24 (12.5%) PR patients required reoperation (2 revision repairs, one conversion to rTSA). There were 3 surgical complications among 42 rTSA patients (7.1%) (2 acromial stress fractures; 1 dislocation requiring open reduction). There were 4 non-surgical complications in the SCR group and 1 stroke in the rTSA group. One SCR patient and 3 rTSA patients were deceased. Multivariate analysis demonstrated no independent predictors of revision surgery, and the only independent predictors of patient satisfaction to be improved pre-op active ER ROM (p=0.03) and strength (p=0.048). An increased AH interval distance was an independent predictor of improved post-op strength (p<0.02).
Conclusion
SCR, PR, and rTSA for massive, irreparable RCT without arthritis all significantly improved post-op strength and outcome scores with >80% patient satisfaction, but with rTSA having worse post-op ROM. For all patients, increased pre-op ER ROM and strength correlated with improved patient satisfaction, while increased AH distance correlated with improved post-op strength.
Shoulder
Glenohumeral
Repair/Reconstruction
Tears
Allograft
Arthroplasty
Arthroscopy
Infraespinatus Tendon Injury
Outcome Studies
Subescapular Tendon Injury
Supraespinoatus Tendon Injury
Sutures/Knots/Anchors
Tendon
Teres Minor Injury
Total Joint Replacement

### 19369 Osteoarthritis therapies in the clinical trial pipeline: a 2020 review

Nicholas N DePhillipo1
Zachary S Aman1
Travis Dekker1
Gilbert Moatshe2
Jorge Chahla1
1USA
2Norway
Summary
Low number of OA disease-modifying therapies in current clinical trial pipeline
Data
Introduction
Osteoarthritis (OA) is a growing problem in the adult population, leading to morbidity, increased health costs and reduced participation in the work force. Information on ongoing trials is essential to better understand future directions of clinical research for OA and optimize the use of research funding. The objective of this study was to conduct a review of active U.S. based clinical trials investigating prevention, symptom resolution, and disease-modifying therapies for osteoarthritis.
Methods
A review of currently active clinical trials for OA using data obtained from the NIH U.S. National Library of Medicine ClinicalTrials.gov database as of August 2020 was conducted. Inclusion criteria were active studies registered in the U.S. that involved the prevention, treatment, or management of OA. Exclusion criteria were trials registered outside of the U.S., studies that evaluated outcome parameters as the primary endpoint that were unrelated to OA, study participants with inflammatory joint disease, non-active clinical trials, or in vitro investigations. Descriptive statistics were recorded and summarized from each trial. Subanalysis was performed for cellular biologics and pharmaceutical drugs.
Results
3859 clinical trials were identified and 310 were included in final analysis. Of the currently active trials, 89% (n=275) targeted symptom resolution in patients with existing OA, 6% (n=19) targeted OA disease-modifying therapeutics, and 5% (n=16) targeted the prevention of OA in high-risk patients. Primary interventions included medical devices (44%, n=137), pharmaceutical drugs (14%, n=42), surgical procedures (14%, n=42), cellular biologics (13%, n=41), and behavioral therapies (13%, n=41). There was a higher number of disease-modifying therapeutics for cellular biologics than pharmaceutical trials (30% vs.14%, respectively). The majority of trials targeted the knee joint (63%) with 38% of all trials evaluating joint arthroplasty. Of those reporting clinical trial phases (n=93), 2% were in early phase I, 18% were in phase I, 41% were in phase II, 22% were in phase III, and 17% were in phase IV. Funding was split between private sector and government (43% and 49%, respectively), with low rate of funding from industry (8%) partners.
Conclusion
There is a broad pipeline of trials evaluating the treatment of OA, with the majority of focus including medical devices, joint replacement surgery, and therapeutic injections. Nearly 90% of currently active U.S. clinical trials target symptomatic resolution for patients with existing OA, with a low number of reported trials targeting OA disease-modifying therapies and prevention of posttraumatic OA development. There was a higher number of disease-modifying therapeutics in the clinical trial pipeline for cellular biologics than pharmaceutical drugs, indicating a promising area of future clinical therapy for OA treatment. Current funding of clinical trials was split between private sector and government, demonstrating an overall lack of industry funding for the treatment and management of OA. The development of OA disease-modifying therapies is essential to reduce the cost and morbidity associated with the increasing prevalence of symptomatic OA in the U.S.
Orthopaedic Sports Medicine
Biologics
Osteoarthritis
Ankle/Foot/Calf
Arthritis
Arthroplasty
Arthroscopy
Bones
Cartilage
Economic Analysis
Elbow/Wrist/Hand
Elderly
Evidence Based Medicine
Glenohumeral
Hip/Groin/Thigh
Joints
Knee
Ostheoarthritis
Preventative Sports Medicine
Shoulder
Stem Cell Therapy
Team Physician

### 19330 The lateral femoral notch sign entails increased rotatory laxity after ACL-injury. Pivot shift quantification with surgical navigation system

Gian Andrea Lucidi
Piero Agostinone
Stefano Di Paolo Eng
Alberto Grassi
Luca Macchiarola
Giacomo Dal Fabbro
Nicola Pizza
Stefano Zaffagnini
Italy
Summary
A lateral norch sign greater than 2 mm is indicative of high grade pivot shift.
Data
Background
The lateral femoral notch sign (LNS) is a bony impression on the lateral femoral condyle correlated with anterior cruciate ligament (ACL) injury. Its presence is associated with lateral meniscus injury and higher cartilage degradation on the lateral femoral condyle.
Hypothesis/Purpose
The present study aimed to investigate the effect and magnitude of LNS on rotatory instability. The hypothesis was that a positive LNS was correlated with a high-grade pivot shift (PS). Study design: Cross-Sectional Study; Level of evidence, 3.
Methods
90 consecutive patients with complete ACL tears from 2013 to 2017 underwent intraoperative kinematic evaluation with the surgical navigation system, and were included in the present study. The same surgeon performed a standardized PS under anesthesia. The PS was quantified through the acceleration of the lateral compartment during tibial reduction (PS ACC) and the internal-external rotation (PS IE). LNS presence and depth were evaluated on sagittal MRI images (1.5 Tesla).
Results
In 47 patients, the LNS was absent. In 33, the LNS depth was between 1 mm and 2 mm, and in 10 patients, it was higher than 2 mm. Patients with a notch deeper than 2 mm showed increase PS ACC and PS IE compared with the group without the LNS. However, no significative differences were present between the group with a notch between and 1 and 2 mm and the patients without LNS.
Conclusion
The presence of a lateral LNS deeper than 2 mm could be used to preoperatively identify patients with a high risk of increased rotatory instability. Clinical Relevance: The LNS could be useful in the clinical setting to set patient’s expectations and probably modify the surgical planning in terms of graft choice and additional lateral extra-articular procedures.
Knee
ACL
Instability
Ligaments
Repair/Reconstruction
Arthroscopy
Biomechanics
MRI

### 19309 Reattachment of posterior cruciate ligament bony avulsion without capsulotomy using transverse posterior incision – ‘A technical note’

Sharath Kittanakete Ramanath
India
Summary
A minimally invasive transverse incision is an effective surgical technique to fix posterior cruciate ligament avulsion fractures over its tibial attachment provided the surgeon has good understanding of the anatomy of the posterior aspect.
Data
Background
Posterior cruciate ligament injuries are not as common as anterior cruciate ligament injuries with avulsion injuries over the tibial attachment of posterior cruciate ligament being even more uncommon. Avulsion fractures are traditional fixed by a large incision which increases pain and affects rehabilitation.
Purpose
A minimally invasive approach to fix posterior cruciate ligament avulsion injuries using basic instruments.
Materials and Methods
Single centre single surgeon study. The study included 12 males and 4 females. The mean follow-up period was 36.12 months. Fixation was done through a transverse incision over the posterior knee crease. Fixation was done with cannulated cancellous screws.
Results
There was a significant improvement in the Lysholm score (from a mean of 7.6 before surgery to 93.6 after surgery). This improvement was statistically significant as tested by Wilcoxon Signed Ranks Test. All the patients achieved a good range of knee flexion at final follow-up (mean of 126 degrees) with no posterior sag. Radiological union at fracture site was noted in all the cases.
Conclusion
A minimally invasive transverse incision is an effective surgical technique to fix posterior cruciate ligament avulsion fractures over its tibial attachment provided the surgeon has good understanding of the anatomy of the posterior aspect. This technique helps us to avoid the traditional large incisions which were used to fix these fractures and thus, improves the post-operative outcome and reduces the morbidity.
Knee
Ligaments
PCL
Repair/Reconstruction
Outcome Studies
Practice Management

### 19318 Natural history of femoroacetabular impingement: using machine learning to evaluate risk factors for osteoarthritis in a large geographic population over the long-term

Ayoosh Pareek1
Sunho Ko2
Heath Melugin1
Changwung Jo3
Ryan R Wilbur1
Bryant M Song1
Aaron J Krych1
1USA
2North Korea
3Republic Of Korea
Summary
Machine learning allows accurate prediction of osteoarthritis in patients with FAI given imaging, paitent, and physical exam parameters.
Data
Introduction/Purpose
Femoroacetabular impingement (FAI) is a major factor for functional limitation and osteoarthritis, yet very little is known about the disease progression or future development of osteoarthritis. Most studies evaluating FAI are conducted with small cohorts or over the short-term. Therefore, the purpose of this study was to use machine learning to develop a predictive model of risk factors that influence progression to osteoarthritis (OA) in patients with FAI that did not have surgical intervention.
Methods
Between 2000 and 2016, medical records of all patients diagnosed with FAI in the Rochester Epidemiology Project (REP) were reviewed. The REP is a medical record database providing access to the complete medical records (all medical encounters) for all residents of Olmsted County, Minnesota, USA; it has been described in detail previously and has been validated for reliability and accuracy in population-based studies. All available radiographs were reviewed. Patient demographics, physical exam, and imaging characteristics (ex: cam lesion, alpha angle, Tonnis grade) were included for model creation. For the initial prediction method, a Gradient Boosting Machine algorithm was selected due to its predictive power and efficiency. The primary outcome for progression was radiographic progression of symptomatic hip osteoarthritis via Tonnis Grade. We used 10-fold nested cross-validation to determine accuracy of the model.
Results
Total of 1045 patients with a mean age of 28.5 years (SD 9.4), alpha angle of 61 degrees (SD 14.4), Tonnis angle of 4.4 degrees (SD 6.8), lateral center edge angle (LCEA) of 32.3 degrees (SD 6.8) were included. The mean follow-up was 24.9 years (SD 12.5 years). A machine learning model using the above methodology was created using two discrete steps. The first model was built using only imaging related parameters such as LCEA and Tonnis Grade (among others). The second model was build using both imaging related parameters in addition to patient (age, BMI, etc) and physical exam (FAI impingement signs, groin pain, etc) parameters. The overall area under the curve (AUC) of the first model was 72.5% (95% CI 67.8 to 77.1) which was significantly improved to 81.9% (95% CI 77.7 to 86.2). This model’s top two of the three features in order of importance were demographic related (age at diagnosis, BMI, Figure 1). This model was utilized to partition the patients into low- and high-risk groups based on probability of OA progression. The mean survival for the high-risk group was significantly lower (121.9 months) than the low-risk group (201.9 months) for OA progression corresponding to an approximate survival of 90.4% vs 56.7% at 10-year follow-up, respectively (p<0.001).
Conclusion
Femoroacetabular impingement continues to be a common cause of osteoarthritis in young patients. In this long-term follow-up of a large geographic cohort treated nonoperatively, machine learning was successful in accurately predicting osteoarthritis progression given preoperative imaging, patient, and physical exam parameters. In addition, age, BMI, and Tonnis grade at initial presentation appear to be the most important three factors affecting osteoarthritis progression.
Hip/Groin/Thigh
Arthroscopy
Impingement
Arthritis
Cartilage
Cartilage Treatment
Femoroacetabular Impingement
Labrum
Labrum Tears
Labrum Treatment
MRI
Osteoarthritis
Outcome Studies
Physical Examination
X-ray

### 19320 Predicting factors for achieving minimally clinical important difference after primary shoulder arthroplasty: a machine learning model

Ayoosh Pareek
Micah Nieboer
Jianing Man
Ronda Esper
Kalyan Pasupathy
Joaquin Sanchez-Sotelo
USA
Summary
Machine learning methodology identified age, BMI, and forward flexion as the most important factors in prediction of MCID after shoulder arthroplasty
Data
Introduction/Purpose
Previous studies have tried to predict minimally clinical important difference (MCID) after total or reverse shoulder arthroplasty (TSA, RSA). However, they have been limited by either small sample sizes or lack of detail on the accuracy of their predictive results. The purpose of this study was to use machine learning to develop a predictive model for achieving MCID after TSA and RSA considering demographic, psychosocial, and physical exam factors.
Methods
All patients who underwent primary TSA or RSA by a single surgeon with preoperative and 1-year postoperative ASES scores were evaluated to determine whether they had achieved maximal clinical benefit from the procedures. Patients with complications or reoperations from the surgery within the first year were excluded due to obvious effect on ASES scores. The study population included 166 patients (49% male) that had undergone TSA (36%) or RSA (64%) with a mean age of 70.4 (SD 8.8).Data collected included patient demographics (age, BMI, gender, diabetes and other), psychosocial factors (tobacco use, mental health disorders), physical exam parameters type of implant, and indication for arthroplasty. Data was randomly divided into two sets (80% for training and 20% for testing) and various machine learning algorithms were compared (Neural Network, Regression Tree, XGBoost, and Random Forest). The XGBoost ensemble method had the highest accuracy and was chosen.
Results
Overall, the mean preoperative to postoperative ASES score change was 40.5 points (SD 22.9, p<0.001) and 74% patients achieved MCID. A machine learning model using the above methodology was created using two discrete steps. The first model was built using all parameters except for preoperative ASES score. The second model was built using imaging related parameters in addition to preoperative ASES scores to evaluate the increased accuracy in prediction. For the first model, the four most important variables were age at surgery, BMI, preoperative external rotation, and preoperative forward flexion (Figure 1). The overall area under the curve (AUC) of the test data model was 80%, which was deemed to be a very good model (Figure 2). The second model including preoperative ASES scores had an increased accuracy of testing data of 85%. In addition, this model did not rely on the same variables, as ASES became the most important variable in addition to BMI, age, and preoperative forward flexion (Figure 3).
Conclusion
In our study, 75% of the patients who had undergone primary shoulder arthroplasty had achieved MCID at one year. Machine learning methodology identified age, BMI, and forward flexion as the most important factors in prediction of MCID. The addition of preoperative ASES scores appears to improve model predictability when predicting which patients will achieve MCID.
Shoulder
Arthroplasty
Glenohumeral
Osteoarthritis
Arthritis
Arthro-MRI
Bones
Cartilage
CT-Scan
Elderly
Evidence Based Medicine
Implant
MRI
Muscle
Outcome Studies
Physical Examination
Subescapular
Subescapular Tendon Injury
Tendon
Total Joint Replacement
X-ray

### 19258 Repeat revision TKR for failed management of periprosthetic infection has long term success but often require multiple operations: a case control study

Huan Dong
Rajpal Nandra
Michael Parry
Jonathan Stevenson
Lee Jeys
UK
Summary
Management of PJI should occur in specialist revision centres
Data
Aims
Management of prosthetic joint infection (PJI) is associated with poor outcomes and catastrophic complications. The aim of this study was to present the outcomes of re-revision surgery for PJI of the knee following previous failed two-stage exchange arthroplasty.
Methods
We retrospectively analysed 32 patients who underwent re-revision knee arthroplasty, having already undergone at least one previous two-stage exchange for PJI, between 2009 and 2018, with a minimum follow-up of two years(mean follow-up 40 months(2 to 99 months)). Outcomes were compared to a matched control of two-stage revisions for PJI of a primary knee replacement. Primary outcomes investigated were eradication of infection and re-operation. Secondary outcomes were five-year mortality and limb-salvage rate.
Results
Successful eradication of infection was achieved in 50% of patients following re- revision surgery at the first treatment episode, compared with 91% following two-stage exchange of primary knee replacement for PJI (p<0.001). Fourteen(44%) patients required further re-operation compared with three (9%) patients in the primary group (p=0.006). Amputation was performed in one case(3%) with thirteen patients(92%) had infection controlled by DAIR, further revision surgery or arthrodesis. Two patients died with infection (6%) and therefore the long-term rate for infection control was 91%. The mean number of procedures following surgery for the re-revision group was 2.8(0-9) compared with 0.13 (0-1) for the primary two-stage group (p<0.001). Five-year patient survival was 90.6%(95% CI 77.1 to 100). Multi-drug resistant organisms were present in 14(44%) patients in the re-revision group. The limb-salvage rate for the re-revision cohort was 97% at final follow-up.
Conclusion
Outcomes for re-revision knee arthroplasty for PJI have higher re-operation and failure rates, but no worse mortality than in revisions of primary knee replacements for PJI. Failures can successfully be managed by further operation. This supports the move to concentrate expertise for eradicating recurrent knee PJI within specialist MDTs.
Knee
Failed
Arthritis
Arthroplasty
Bones
Implant
Outcome Studies
Physical Examination
X-ray

### 19238 A goal-based return to sport following knee arthroplasty: a prospective study using functional criteria and gait analysis

Ahmed A Magan
Babar Kayani
Ricci Plastow
Justin Chang
UK
Summary
Goal-based RTS criteria have reduced time to sport compared to time-based criteria. Patients continue to improve for a considerable period after returning to sport.
Data
Introduction
There is no consensus over time to return to sport (RTS) following arthroplasty; patients are usually given a period of three to six months. The objectives of this study were to determine criteria that would allow earlier return to sport than the time-based method.
Patients & Methods
This prospective study included 50 patients that participated in amateur sports before the onset of their knee arthritis. The study included 28 males and 22 females with a mean age was 62 ± 4.5 years. All study patients underwent Total Knee Arthroplasty (TKA) by a single surgeon, and received a milestone-based rehabilitation programme with the goal of getting back to golf or tennis at the earliest opportunity. Functional outcomes were recorded after surgery at 3,6,9 and 12 weeks, and gait analysis was performed using a force plate treadmill after 3 months, and 24 months. Mean follow-up was 27.8 months (range, 24 to 35 months).
Results
96% (48) returned to their goal level of sporting activity. Mean time for full RTS activity was 10 ± 3.5 weeks, although some patients were able to start as early as 4 weeks after surgery. At two years follow-up, study patients had improved mean Oxford knee scores (40 ± 3.1 vs 16 ± 3.5 respectively, p<0.001), Forgotten Joint scores (46 ± 8.5 vs 8 ± 3.5 respectively, p<0.001) and improved lower extremity functional scores (68 ± 3.2 vs 29 ± 2.2 respectively, p<0.001) compared to preoperative values. Gait analysis revealed significantly better cadence, walking speed, stride length and stance time, for all sporting activities at 24 months compared to 3 months.
Conclusion
Goal-based RTS criteria have reduced time to sport compared to time-based criteria. Patients continue to improve for a considerable period after returning to sport.
Knee
Osteoarthritis
Total Joint Replacement
Outcome Studies

### 19249 Concurrent treatment of a displaced bucket handle and anterior cruciate ligament reconstruction: a higher risk of stiffness?

Etienne Deroche
Cécile Batailler
John Swan
Sebastien Lustig
Elvire Servien
France
Summary
There is an increased risk of revision for arthrolysis after simultaneous treatment of DBH and ACL reconstruction.
Data
Objectives
Postoperative stiffness is feared after anterior cruciate ligament (ACL) reconstruction. A bucket handle meniscal tear associated with an ACL tear requires urgent surgical treatment and may delay full range of motion (ROM) recovery. We hypothesize that the concurrent treatment of a displaced bucket handle (DBH) meniscal tear and ACL reconstruction is associated with an increased risk of revision for arthroscopic arthrolysis.
Methods
A retrospective case-control study of consecutive patients with ACL reconstruction performed between January 2009 and December 2018. Group A (cases) involved all patients who underwent simultaneous ACL reconstruction and DBH meniscal tear treatment, and patients in group B (2 controls for each case) underwent isolated ACL reconstruction. Groups were matched for age, sex, body mass index. The primary outcome was re-operation rate for arthrolysis <12 months after surgery. Other outcomes were stiffness in flexion and extension at 6 weeks and 6 months after surgery. Study Design: Case-control study, Level of Evidence: Level 3.
Results
69 patients were included in group A, 40 men (58%) and 29 women (42%) and 139 patients in group B, 68 men (49%) and 71 women (51%). Mean age was 29 +/_ 11.2 years in group A and 30 +/_ 10.4 years in group B. The revision rate for arthrolysis was higher in group A compared to group B, 7 (10.1%) and 4 (2.9%) patients respectively (p=0,044), with a survival rate of 89.7% (CI95% 82.7–97.2) and 97.1 (CI95% 94.3–99.9) respectively (p=0.023). There was more stiffness in flexion and in extension in group A after 6 weeks and after 6 months (p>0.05). The risk for arthrolysis was not statistically different regarding the delay from accident to surgery for the global series (p=0.421) and in group A specifically neither (p=0.887). The DBH was sutured for 39 patients (56.5%), with 3 failures (7.7%) after 12 months follow-up. Arthrolysis was performed for 6 patients treated by meniscal suture (15.4%) and for only one patient treated by meniscectomy (3.3%) (p=0.128).
Conclusion
Our study confirms an increased risk of revision for arthrolysis after simultaneous treatment of DBH and ACL reconstruction. The influence of the delay for surgery after ACL rupture and the type of DBH treatment (suture or meniscectomy) on postoperative stiffness has not been demonstrated.
Knee
ACL
Arthroscopy
Ligaments
Stiff Joints
Biomechanics
Lateral
Medial
Meniscus
MRI
Outcome Studies
Physical Examination
Rehabilition/Physical Therapy
Repair/Reconstruction
Single Bundle
Sutures/Knots/Anchors
Tears
Trauma

### 19266 Assessing the risk of osteoarthritis progression and femoral head collapse following hip corticosteroid/anesthetic injection

Christopher T Eberlin
Paul F Abraham
Kirstin Small
Nehal Shah
Luis S Beltran
Michael Peter Kucharik
Christopher T Eberlin
Scott Martin
USA
Summary
This study reinforces the safety of corticosteroid injection (CSI), as patients treated by CSI did now show significantly greater rates of osteoarthritis progress and new femoral head collapse.
Data
Introduction
In the absence of definitive Level I evidence regarding the safety of hip CSI, there have been an increasing number of retrospective case series studying outcomes after hip corticosteroid injection (CSI). Recent studies have suggested that hip CSI may be associated with increased rates of avascular necrosis (AVN), subchondral insufficiency fracture (SIF), femoral head articular surface collapse, and accelerated progression of osteoarthritis (OA), but these studies do not compare against a control arm matched for baseline OA severity or exclude patients with pre-injection AVN or SIF from analysis, causing selection bias.
Methods
Results
186 hips in the CSI group [mean ±95% CI age: 55.8±2.1, mean±95% CI BMI: 27.5±0.8, 69 (37.1%) males, 100 (53.8%) right hips] and 186 hips in the control group [mean ±95% CI age: 55.7±2.3, mean±95% CI BMI: 28.0±0.8, 69 (37.1%) males, 96 (51.6%) right hips] were included in this study. There were no significant differences between groups in age, gender, BMI, laterality, baseline OA severity, or baseline AVN/SIF on index MRI. Analysis of adjudicated radiographic outcomes were performed after exclusion of 61 matched pairs with at least 1 instance of pre-existing AVN or SI (Table 1). Rates of OA progression (5.6% vs. 2.4%; p=0.33), new AVN or SIF (1.6% vs. 0.0%; p=0.50), and new femoral head collapse (3.2% vs. 2.4%; p=1.000) were all similar between groups. Of the 4 cases of new femoral head collapse in the CSI group, 2 were classified as femoral head remodeling secondary to OA, leaving only two (1.6%) definitive femoral head collapses secondary to AVN or SIF. Of the 3 cases of new femoral head collapse in the control group, 2 were classified as femoral head remodeling due to an unknown etiology, leaving only one (0.8%) definitive femoral head collapses secondary to AVN or SIF.
Discussion
When controlling for baseline OA severity and pre-existing AVN or SIF, patients treated by CSI in our study showed OA progression in only 6% of cases and new femoral head collapse in only 3% of cases, which was not significantly greater than control and similar to the expected progression of natural disease. Future multicenter, randomized, double-blind, placebo-controlled trials investigating safety of hip CSI are needed.
Hip/Groin/Thigh
Cartilage
Osteoarthritis
Epidemiology
MRI
Practice Management
X-ray

### 19267 Utilizing laser doppler flowmetry to measure labral blood flow during arthroscopic acetabular labral repair

Christopher T Eberlin
Paul F Abraham
Mark R Nazal
Michael Peter Kucharik
Christopher T Eberlin
Stephen M Gillinov
Scott Martin
USA
Summary
Laser doppler flowmetry of blood flow to the acetabular labrum found no statistically significant difference before and after suture repair. Post- repair blood flow was relatively more preserved medial to the suture than lateral.
Data
Introduction
To our knowledge, no study has evaluated the effects of suture placement on microvascular supply during hip arthroscopy. The purpose of this study was to examine the effects of labral repair on labral perfusion in vivo, using laser doppler flowmetry (LDF) to measure microvascular blood flow.
Methods
Patients undergoing arthroscopic repair of the acetabular labrum by a single surgeon were prospectively enrolled between June 2018 and March 2020. An LDF probe (Moor Instruments; Wilmington, DE) was used to measure microvascular blood flow flux, measured in perfusion units (PU). Up to 8 LDF measurements were taken for each patient: 1 recording before and after labral elevation from the acetabular rim; 2 recordings before and after tie down of the first suture (one medial and one lateral to the suture); and if multiple anchors were necessary to carry out the repair, 1 recording before and after tie down of the second suture lateral to this suture. Some measurements were unable to be recorded due to inability to locate a nearby blood vessel and/or time constraints during surgery.
Results
21 patients [13 (61.9%) males; 8 (38.1%) females] met study criteria. Measurements before and after labral elevation were collected for 12 patients (11 loop suture repairs vs. 1 vertical mattress repair). Prior to labral elevation, the mean (95% CI) blood flow was 87.79 (52.18, 123.4) PU, and after labral elevation, mean blood flow was 90.78 (58.68, 122.87) PU (p=0.892). Measurements before and after first suture tie down were collected for 15 patients (13 loop suture repairs vs. 2 vertical mattress repairs) lateral to the position of the suture. Mean blood flow at this position was 79.77 (42.39, 117.16) PU before suture tie down and 62.33 (43.58, 81.08) PU after suture tie down (p=0.379). Measurements before and after first suture tie down were collected for 11 patients (10 loop suture repairs vs. 1 vertical mattress repair) medial to the position of the suture. Mean blood flow at this position was 66.09 (9.73, 122.46) PU before suture tie down and 90.07 (30.06, 150.08) PU after suture tie down (p=0.524). Measurements before and after second suture tie down were collected for 7 patients (5 loop suture repairs vs. 2 vertical mattress repairs) lateral to the position of the second suture. Mean blood flow was 54.00 (35.26, 72.74) PU before tie down and 117.97 (−31.64, 267.58) PU after suture tie down (p=0.320). Post-repair blood flow was relatively more preserved medial to first suture placement [+23.98 (+2.47, +45.49) PU] than lateral to first suture placement [−17.45 (−48.27, +13.38) PU] (p=0.0371).
Discussion
There was no statistically significant difference in microvascular blood flow to the labrum after labral elevation from the acetabular rim, after first suture placement, or after second suture placement. This suggests that current labral repair techniques may not negatively affect labral perfusion. However, when directly comparing the change in LDF measurements medial and lateral to the site of first suture tie down, post-repair blood flow was found to be relatively more preserved medial than lateral to it.
Hip/Groin/Thigh
Arthroscopy
Labrum
Tears
Labrum Tears

### 19268 Can BMAC application safely diminish perioperative pain in patients undergoing hip arthroscopy?

Michael Peter Kucharik
Paul F Abraham
Mark R Nazal
Stephen M Gillinov
Christopher T Eberlin
Scott Martin
USA
Summary
Patients who received BMAC during arthroscopic labral repair reported significantly less pain than those who did not receive BMAC. Patients receiving BMAC also reported with minimal complications.
Data
Introduction
The purpose of this study was to compare pain levels and medication use in the perioperative period in patients undergoing arthroscopic labral repair with and without BMAC application. The secondary purpose of this study was to report safety of the procedure by evaluating post-operative complications from the perioperative period to final follow-up.
Methods
A prospective cohort of consecutive patients undergoing arthroscopic acetabular labral repair with possible BMAC application between January 2018 and March 2020 were offered enrollment into the study. BMAC was not used in patients with widespread degenerative changes or patients without any discernable degenerative changes. Each patient was prescribed 20 tablets of 5 mg oxycodone and was instructed to take 1 tablet for breakthrough pain of moderate intensity. Patients were instructed to complete a medication and visual analog scale (VAS) pain tracker and return it at their suture removal appointment, approximately 12–14 days after surgery. Outcomes collected from this tracker were compared between the group of patients treated with BMAC and the group not treated with BMAC. In addition, retrospective chart review was conducted for 171 patients who received BMAC by the senior surgeon during arthroscopic acetabular labral repair. Progress notes from the perioperative period until final follow-up were examined for possible complications related to BMAC harvesting and application.
Results
Seventy patients [40 (57.1%) males] completed the medication and pain tracker. 59 (84.3%) of these patients underwent BMAC application. Mean (95% CI) age was 31.71 (29.52, 33.91). On postoperative day #1 (POD#1), VAS pain scores were lower in the BMAC group, approaching statistical significance (4.76 vs. 6.18 p=0.095). The BMAC group reported significantly less pain than the No BMAC group on POD#5 (3.53 vs. 5.18; p=0.010), POD #10 (2.23 vs. 3.73; p=0.014), and the suture removal appointment (1.80 vs. 3.18; p=0.008). The mean length of opioid (4.02 vs. 2.82 days; p=0.348) and NSAID (8.59 vs. 8.00 days; p=0.677) usage did not differ significantly between groups. The total number of opioid (8.47 vs. 7.45; p=0.715) and NSAID (27.83 vs. 21.36; p=0.464) pills taken also did not differ significantly between groups. The maximum number of opioid (2.61 vs. 2.64; p=0.973) and NSAID (5.07 vs. 5.55; p=0.708) pills taken in a single day was also similar. Among the 171 patients in the retrospective cohort, 19 (11.1%) had signs of heterotopic ossification (HO) on follow-up radiograph, 2 (1.2%) progressed to total hip arthroplasty (THA) by final follow-up, and 1 (0.5%) had evidence of neuropraxia. Zero patients had evidence of wound infection, joint infection, skin necrosis, hemorrhage, avascular necrosis, or required a repeat arthroscopic procedure.
Discussion
Patients treated with BMAC at the time of hip arthroscopy had significantly lower VAS pain scores than those not treated with BMAC, despite undergoing bone marrow aspiration—normally a painful procedure. Furthermore, the patients treated with BMAC used opioids and NSAID medications at similar rates as those treated without BMAC. Patients treated with BMAC suffered minimal postoperative complications, as zero patients had evidence of joint infection, wound infection, or hemorrhage secondary to BMAC harvesting and application.
Hip/Groin/Thigh
Biologics
Labrum
Tears
Arthroscopy
Labrum Tears
Outcome Studies

### 19547 Can metal artifact reduction sequence magnetic resonance imaging (MARS-MRI) help in the diagnosis of periprosthetic shoulder infection? A prospective trial

Stephen C Weber
Prashant Meshram
Edward G McFarland
Uma Srikumaran
Jacob Joseph
Jan Fritz
USA
Summary
Metal Artifact Reduction Sequence Magnetic Resonance Imaging (MARS-MRI) study demonstrates a high accuracy and reliability for the making the diagnosis of PSI
Data
Background
The diagnosis of peri-prosthetic shoulder infection (PSI) in patients with painful arthroplasty is challenging. The use of Metal Artifact Reduction Sequence Magnetic Resonance Imaging (MARS-MRI) in diagnosing PSI has been reported but never studied. The goal of this study was to determine its accuracy for making the diagnosis of PSI.
Methods
Patients suspected to have PSI were prospectively recruited from one institution between 2015 and 2019. The inclusion criteria were a minimum of one year follow up and the availability of blood studies, radiographs and MARS MRI. Patients were categorized according to the International Consensus Meeting (ICM) 2018 criteria for PSI. Patients were considered “not infected” if they did not require surgery at last follow up (47/89, 53%)53 or if they did not meet criteria for infection using the criteria of the ICM. The diagnostic accuracy of MARS MRI findings for PSI was quantified as sensitivity, specificity, and accuracy using receiver operator curve (ROC) analysis with area under the curve (AUC).
Results
Of 130 patients who underwent MARS MRI in the study period, 89 (68%) patients met inclusion criteria. The MARS-MARI findings of axillary lymphadenopathy (AUC=0.94, Sn=95%, Sp=92%, OR=4) and edematous synovitis (AUC=0.94, Sn=91%, Sp=97%, OR=10) were highly accurate with very high specificity and sensitivity for the diagnosis of PSI (). Complex joint effusion (AUC=0.86, Sn=86%, Sp=86%, OR=5.7) was found to be accurate with high specificity and sensitivity. Rotator cuff muscle edema (AUC=0.75,OR=3.6) and extraarticular fluid collection (AUC=0.71, OR=5.0) were both moderately accurate and while these criteria had very high specificity (> 90%) they had low sensitivity for diagnosing PSI. While the finding of a sinus tract finding in MARS MRI had a very high specificity (99%) with odds ratio of 9.3, the accuracy (AUC=0.63) and sensitivity (28%) were low. Periprosthetic edema and periprosthetic resorption or osteolysis had low accuracy, sensitivity, and specificity for diagnosis of PSI.
Conclusion
This study demonstrates a high accuracy and reliability of MARS MRI for the making the diagnosis of PSI. This diagnostic test should be considered used when evaluating patients for PSI. These conclusions are based upon a specific MRI protocol with experienced musculoskeletal radiologists.
Shoulder
Arthritis
Arthroplasty
Glenohumeral
MRI

### 19583 Identification of predictive risk factors for the development of a stress fracture within 6 months in female elite long-distance runners

Harukazu Tohyama
Tomoya Ishida
Japan
Summary
Lumbar bone mineral density (BMD) < 81.1% of the young adult mean (YAM) predicted a prospective stress fracture within 6 months with 74% specificity and 88% sensitivity in female elite long-distance runners.
Data
Background
Female runners have a higher risk of stress fractures than male runners. Literature about best practices for preventing stress fractures in female long-distance runners is lacking. We aimed to identify which factors predict the risk of stress fractures within 6 months in female elite long-distance runners. Study design: Cohort study.
Methods
We measured bone mineral densities (whole body and lumbar spine) and body composition using dual-energy X-ray absorptiometry (DXA) in elite female long-distance runners aged 18 to 37 years old (N = 21) who belonged to a women’s track team. We followed participants prospectively for 6-month periods. Stress fractures were confirmed with bone scan, magnetic resonance imaging, and/or computed tomography findings. We used univariate logistic regression and stepwise multivariate logistic regression with the receiver operating characteristics curve to examine the ability of bone mass and body composition parameters alone or in combination to predict the occurrence of a stress fracture.
Results
We performed 118 DXA measurements. Stress fractures (four sacral, three tibial, three calcaneal, two pubic, two femoral neck, one rib, one cuboid, and one metatarsal) occurred in nine runners within 6 months. Bone mineral densities (whole body and lumbar spine), total bone mineral content, lean body mass, and percentage total bone mineral content (relative to total body mass) were significantly associated with a stress fracture developing. The multivariate analysis showed that bone mineral density of the lumbar spine alone was the strongest predictive factor. Bone mineral density of the lumbar spine <81.1% of the young adult mean predicted the occurrence of a stress fracture within 6 months, with and 88% sensitivity and 74% specificity.
Conclusion
Female elite long-distance runners with lumbar spine bone mineral density <81.1% are at increased risk of a stress fracture within 6 months and should reduce their high-impact sports activities to avoid developing a stress fracture. Clinical relevance: The present study provides meaningful information that suggests a possible useful application of DXA measurement as a screening tool in regular medical examinations for predicting stress fractures in female long-distance runners.
Orthopaedic Sports Medicine
Preventative Sports Medicine
Bone Scan
CT-Scan
Female Athletes
Gender Specific
MRI
Sport Specific Population

### 19691 Today’s nonagenarians: too old for arthroplasty?

William Bugbee
Stephen Sizer
Julie McCauley
William Bugbee
USA
Summary
In our matched cohort study, nonagenarians had higher rates of complications than younger patients following total joint arthroplasty.
Data
Introduction
Conventional wisdom suggests that nonagenarians may be “too old” and frail to undergo elective total joint arthroplasty (TJA). Historical studies have reported higher complication rates in nonagenarians. We questioned if this concept is still valid and hypothesized that today’s nonagenarians have equivalent outcomes to younger cohorts undergoing TJA.
Methods
One hundred seventy-four patients undergoing primary TJA between 2010 and 2017 were included; 58 nonagenarians (age 90+) were matched with 58 octogenarians (age 80–84) and 58 septuagenarians (age 70–74). Groups were matched by gender, diagnosis, surgeon, operative joint, and year of surgery. Within each group, 31 patients (53%) underwent total hip arthroplasty (THA) and 27 patients (47%) underwent total knee arthroplasty (TKA). Comorbidities, American Society of Anesthesiologist (ASA) physical status scores, and Charlson comorbidity index scores were captured preoperatively. Complications, readmissions, and mortality occurring within 90 days postoperatively were evaluated.
Results
The overall total complication rate was 12% for septuagenarians, 22% for octogenarians, and 45% for nonagenarians (p<0.001). Nonagenarians were 3.1 times more likely than younger patients to have a complication, after controlling for arthroplasty type (THA vs. TKA), ASA score, Charlson comorbidity index, major medical comorbidities, and discharge disposition (home vs. skilled nursing facility) (p=0.040). When complications were classified as medical, nonagenarians had the highest rate (33%) compared to septuagenarians (3%) and octogenarians (14%) (p<0.001). Orthopedic (surgical) complications were similar between groups. Readmission occurred in 2% of septuagenarians, 5% of octogenarians, and 11% of nonagenarians (p=0.118). There were two deaths (both nonagenarians).
Conclusion
Nonagenarians were 3.1 times more likely than younger patients to have a complication following TJA. The incidence of medical complications was highest in nonagenarians compared to septuagenarians and octogenarians, but rates of orthopedic complications were similar. These results did not support our hypothesis that nonagenarians would have equivalent outcomes to younger cohorts undergoing TJA.
Knee
Arthroplasty
Osteoarthritis
Elderly

### 19595 Autograft vs allograft vs xenograft: ct scan evaluation of glenoid grafting

Ettore Taverna
Caterina Albizzini Ohin
Vincenzo Guarrella
Carlo Perfetti
Italy
Summary
Radiological comparison of different grafts and different fixation techniques.
Data
Purpose to evaluate bone integration and osteolysis of glenoid grafting in the context of shouder anterior-inferior instability.
Methods graft osteointegration and osteolysis was retrospectively evaluated with ct scan imaging performed at 12 months after surgery to compare results of Latarjet procedure, Bone block procedure with allograft and bone block procedure with xenograft. Screw fixation and double endobuttons fixation was also compared.
Results ct scan imaging of 123 patients were analysed. Of these 23 were performed in patients who underwent Bone Block procedure with xenograft and Endobuttons fixation, 55 underwent Bone Block procedure with allograft and Endobuttons fixation, 13 Latarjet procedure with screw fixation and 32 Latarjet with Endobuttons fixation. Osteolysis was inferior in Bone Block procedure compared to Latarjet procedure (12.8% vs 28.9%) but the result vas not statistically significant (P value 0.10). Bone integration was higher in Bone Block procedure than Latarjet procedure but the result was not statistically significant (P value > 0,5). Within the Latarjet procedures Endobuttons fixation resulted in a higher integration rate (87,5% vs 73,6%) and lower osteolysis rate compared to screw fixation (25% vs 38,4%) but the result was not statistically significant. Within the Bone Block procedures the use of a Xenograft resulted in a higher integration rate (92%) and lower osteolysis rate (8%) compared to the use of an Allograft (16,3%) but the result was not statistically significant.
Conclusions
Glenoid bone loss is a major risk factor for recurrence in anterior-inferior shoulder instability. Therefore high rate of bone graft integration and low rate of graft osteolysis are crucial to achieve optimal results. This study shows a lower rate of graft osteolysis after Bone Block procedure compared to Latarjet procedure. Other non statistically significant findings suggest better results in terms of osteolysis and graft integration with xenograft compared to allograft and with double endobuttons fixation compared to screw fixation.
Shoulder
Arthroscopy
Glenohumeral
Instability
Allograft
Autograft
Bones
Capsuloligamentous Complex
CT-Scan
Dislocation
Glenoid Fracture
Labrum
Repair/Reconstruction
Sport Specific Injuries

### 19607 Evolution of graft maturation and tunnel widening during the first year following all-inside graft-link ACL reconstruction: a serial MRI study

Edoardo Monaco1
Etienne Cavaignac2
Fabio Marzilli1
Riccardo Di Niccolo1
Edoardo Gaj1
Alessandro Carrozzo1
Giuseppe Argento1
Andrea Ferretti1
1Italy
2France
3USA
Summary
MRI evaluation of graft healing after ACL reconstruction with all inside graft link technique.
Data
Background
The all-inside graft-link ACL reconstruction technique is based upon the use of a quadrupled semitendinosus graft fixed with adjustable loop suspensory devices (ALD) on both femoral and tibial sides. This technique is gaining popularity due to potential benefits that may include faster recovery, reduced invasiveness, and reduced donor site morbidity, when compared to standard techniques. However, the main concerns with this technique are related to the magnitude of the overall cyclic displacement that may occur with two ALDs. In turn this leads to additional concerns, including the potential increased risk of inferior graft maturation/incorporation and tunnel widening (TW). Objective The primary objective of this study was to prospectively evaluate graft maturation and incorporation, and tunnel widening in a group of patients who underwent all-inside graft link ACL reconstruction using sequential 1.5 T MRI at 3, 6 and 12 months post-operatively.
Methods
20 patients were prospectively enrolled in the study. Inclusion criteria were: age between 16 and 50 years, chronic ACL tear (injury-surgery interval more than 2 weeks) confirmed by physical examination and preoperative MRI, a healthy contralateral side, and no prior injures to the affected knee. 1.5 T MRI was performed at 3, 6 and 12 months post-operatively to evaluate graft maturation and integration and tibial tunnel widening. The following parameters were considered at each follow-up: signal-to-noise quotient (SNQ), bone-graft integration scale (signal intensity at the bone-graft interface), ligament signal by Howell scale, and tibial tunnel widening. Radiological parameters were evaluated by an expert radiologist and an orthopedic surgeon. The final clinical evaluation was performed at a minimum follow-up of 2-years. This included physical examination, patient-reported outcomes (PROs) and KT-1000 arthrometer. The Mann-Whitney U test was used to analyze differences in imaging findings between different time points.
Results
The mean signal-to-noise quotient (SNQ) was 4.4 ± 2.6 at 3 months post-op, 1.6 ± 0.7 at 6 months post-op and 1.9 ± 1.4 at 12 months post-op. There was a statistical difference between 3 and 6 months (p=0,028) and between 3 and 12 months (p=0.05) with no differences between 6 and 12 months. The mean tibial tunnel widening was 41.2% ± 36.7% at 3 months, 52.4% ± 18.7% at 6 months and 45.5% ± 46.6% at 12 months. Tunnel widening reduced significantly at 12 months post-operatively when compared to 6 months post-operatively (p=0.5). The Howell scale show statistically significance between 3 and 12 months, with patients identified as Grade 1 going from 30% to 70% (p=0.05). The bone-graft integration scale show statistically significance between 3 and 12 months, with patients identified as Grade 1 go from 45% to 65%, comparing 3 and 12 months (p=0.01).
Conclusion
Significant maturation and incorporation of all-inside graft-link ACL grafts occurs by 6 months post-operatively, with no further maturation apparent between 6 and 12 months. These promising results suggest that even if cyclic displacement occurs it does not compromise maturation and incorporation. These findings are supported by a significant reduction in tibial tunnel diameter and MRI evidence of graft healing occurring within the tibial socket by 12 months post operatively.
Knee
Capsuloligamentous Complex
Repair/Reconstruction
Tears
MRI
Outcome Studies

### 19673 Biomechanical comparison of stemless humeral components in total shoulder arthroplasty

Ilya Voloshin
Raymond Chen
Emma Knapp
Anthony Miniaci
Ilya Voloshin
USA
Summary
The purpose of this study was to compare initial fixation strength between various stemless and stemmed humeral components and to correlate component fixation strength of each implant with bone mineral density (BMD).
Data
Background
The ideal design for stemless humeral components in total shoulder arthroplasty is currently unknown. Comparison of primary stability between different designs is lacking. The purpose of this study was to compare initial fixation strength between various stemless and stemmed humeral components and to correlate component fixation strength of each implant with bone mineral density (BMD).
Methods
Results
At maximal axial loading, Simpliciti demonstrated greater micromotion (540 µm) than OVOMotion (192 µm), p=0.003. Simpliciti and Sidus (387 µm) also had greater micromotion than Short stem (118 µm, p<0.001, p=0.03) and Standard stem (85 µm, p<0.001, p=0.01). When comparing low BMD samples at maximal axial loading, these differences were accentuated, but comparison of high BMD samples showed no significant differences between groups. Torsional testing demonstrated that Standard stem failed at greater torque (7.2 Nm) than Simpliciti (2.3 Nm, p<0.001), Sidus (1.9 Nm, p<0.001) and OVOMotion (3.9 Nm, p=0.01). When comparing torsional testing results of low BMD samples, both Standard stem and Short stem failed at greater torque than Simpliciti (p=0.02, p=0.003) and Sidus (p=0.03, p=0.004) but failed at a similar torque to OVOMotion. Torsional testing of high BMD samples showed that Standard stem failed at a greater torque than all stemless designs.
Conclusions
Primary fixation of stemless and stemmed humeral implants depends on implant design and proximal humeral bone quality. OVOMotion demonstrated less micromotion than Simpliciti during axial loading testing. Stemmed implants (short and standard length) outperformed Simpliciti and Sidus in low BMD specimen (<0.35 g/cm2) during both maximal axial loading and torsional testing. Of the tested stemless designs, OVOMotion (central screw and peripheral rim-fit design), demonstrated greater primary stability at low BMD when compared to Simpliciti and Sidus, while all stemless designs performed similarly at high BMD.
Shoulder
Arthroplasty
Glenohumeral

### 19723 Alpha angle more useful than femoral head-neck offset to predict intra-articular damage in patients with FAI undergoing hip arthroscopy

Benjamin G Domb
Jacob Shapira
Philip Joseph Rosinsky
Hari Krishna Ankem
Bezalel Peskin
Ajay C Lall
Benjamin G Domb
USA
Summary
In a multivariate analysis, factors identified as preoperative predictors of intra-articular cartilage damage in patients with FAI were age, sex, ACEA, and alpha angle.
Data
Purpose
To identify radiographic measurements and demographics that are predictive of intra-articular cartilage damage in patients with femoroacetabular impingement (FAI) undergoing hip arthroscopy. More specifically, to compare the predictive value of alpha angle and femoral head-neck offset in determining the preoperative likelihood and severity of intra-articular cartilage damage.
Methods
Patients were included if they underwent primary hip arthroscopy between February 2008 and June 2020. A total of 13 variables were assessed in a bivariate comparison and analyzed in a multivariate logistic model. The Acetabular Labrum Articular Disruption (ALAD) and Outerbridge (OB) classifications were used to define acetabular cartilage defects. Those without damage or those with mild acetabular cartilage damage belonged to the ALAD/OB = 2 group and those with severe acetabular cartilage damage belonged to the ALAD/OB = 3 group.
Results
The multivariate logistic regression selected age, sex, anterior center-edge angle (ACEA), and alpha angle. Every additional degree in the alpha angle was associated with a 6% increase in the odds of severe acetabular cartilage damage defined as ALAD/OB = 3 (OR, 1.06 [95% CI, 0.12–8.11]). The multivariate analysis did not identify femoral head-neck offset as a predictor. The odds of severe acetabular cartilage damage were 3.73 times higher in males than females (OR, 3.73 [95% CI, 0.01–1705.96]). Higher age (per log 10 unit) was found to increase the likelihood of ALAD/OB = 3 (OR, 1.04 [95% CI, 0.13–7.75]).
Conclusions
In a multivariate analysis, factors identified as preoperative predictors of intra-articular cartilage damage in patients with FAI were age, sex, ACEA, and alpha angle. Femoral head-neck offset was not predictive, suggesting alpha angle may take precedence as a predictor of intra-articular cartilage damage. These findings may be helpful to the clinician’s efficient utilization and selection of radiographic predictors of intra-articular cartilage damage in patients with FAI undergoing hip arthroscopy.
Hip/Groin/Thigh
Arthroscopy
Impingement
Cartilage
Cartilage Treatment
Femoroacetabular Impingement
Labrum
Physical Examination
X-ray

### 19570 Long term clinical outcome of combined autologous bone and articular cartilage chip transplantation for osteochondral lesions in the knee

Bjørn Borsøe Christensen
Morten Lykke Olesen
Casper B Foldager
Kris TC Hede
Jonas Jensen
Martin Lind
Denmark
Summary
Autologous bone and cartilage transplantation for osteochondral injuries in the knee.
Data
Purpose
Osteochondral injuries have proven difficult to treat. Several treatments are available, but no gold standard treatment exists. Our group presented the short-term data on Autologous Dual-Tissue Transplantation (ADTT) in 2015. ADTT is a one-step, combined autologous bone and articular cartilage chips transplantation. The aim of this study was to investigate the long-term results using MRI, CT and subjective and functional clinical outcome scores.
Methods
Eight patients (age 32 ± 7.5 years) suffering from osteochondritis dissecans in the knee were included. The lesion was debrided, and the osteochondral defect was filled with autologous bone, to a level at the base of the adjacent cartilage. Cartilage from the intercondylar notch was chipped using a scalpel and embedded in fibrin glue in the defect. Radiologic evaluation was performed using MRI and CT preoperatively, at one and at 7.5 years, and patient reported outcome scores were used to assess subjective and functional clinical outcome preoperatively and at one, two, five and 7.5 years (IKDC, KOOS and Tegner activity score).
Results
The preoperative IKDC score increased from 35.9 to 68.1, 73.0, 75.3 and 72.9 after one, two, five and 7.5 years (p<0.01). The Tegner score improved from 2.5 to 4.7, 4.8, 4.8 and 4.6 at one, two, five and 7.5 years (p<0.001). All KOOS subscores improved at one year and the improvements persisted at two, five and 7.5 years (p<0.01). Cartilage tissue repair evaluated using MOCART score improved from 22.5 to 53.1 at one year (p<0.01), with a slight deterioration to 44.3 after 7.5 years (not statistically significant). CT imaging demonstrated good subchondral bone healing at one year, with an average bone defect filling of 80%. At 7.5 years CT showed an improvement in all patients with an average bone filling of 90% and a more even surface than at one year.
Conclusion
ADTT resulted in good subchondral bone restoration and cartilage repair. Significant improvements in patient reported outcome was found at one year postoperative and the improvements persisted at two, five and 7.5 years. This study suggests ADTT as a promising, low-cost, treatment for osteochondral injuries.
Orthopaedic Sports Medicine
Arthroscopy
Osteoarthritis
Outcome Studies

### 19572 High mid-term survival of condyle resurfacing implants in the knee – a nation-wide cohort study on 379 observations from The Danish Knee arthroplasty registry

Bjørn Borsøe Christensen
Anders El-Galaly
Jens Ole Laursen
Martin Lind
Denmark
Summary
80% Survival 10 years after treatment with Condyle Resurfacing Implants in the Knee
Data
Purpose
Focal cartilage injuries are debilitating and difficult to treat. Biological cartilage repair procedures are suited for patients younger than 40 years, and knee arthroplasties are generally reserved for patients older than 60. Condyle resurfacing implants are well suited for patients in this treatment gap. Our objective was to investigate the midterm survival of condyle resurfacing implants from a nationwide cohort registered in the Danish Knee Arthroplasty Registry.
Methods
In this retrospective cohort study, 379 registrations of condyle resurfacing implants were followed longitudinally in the Danish Knee Arthroplasty Registry from 1997 to 2020. The study’s primary endpoint was revision surgery. The survival of the condyle resurfacing implants was primarily analyzed by Kaplan Meier method.
Results
379 condylar implants were retrieved from the DKR. The mean age and weight of patients receiving condyle resurfacing implants were 50 years (SD: 11) and 84 kg (SD: 17). The indications for condyle resurfacing implants were: Secondary osteoarthritis (42%), primary osteoarthritis (32%) and osteochondral lesions (20%). Within the follow-up period, 70 (19%) of the implants were revised to arthroplasties. The 1-, 5- and 10-year revision free survival estimation was 0.95 (95% CI: 0.93–0.97), 0.84 (95% CI: 0.80–0.88) and 0.80 (95% CI: 0.75–0.84). The median time to revision was 2 years.
Conclusion
The 10-year revision free survival rate of 80% is high compared with the available biological cartilage repair techniques. Improved patient selection could improve the implant survival rate further and can help fill the treatment gap of focal cartilage injuries in patients aged 40–60.
Knee
Cartilage
Implant
Osteoarthritis
Arthroplasty
Cartilage Injuries
Cartilage Treatment
Epidemiology

### 19767 Dynamic radiostereometry evaluation of two different anterior cruciate ligament reconstruction techniques: does single bundle reconstruction plus lateral plasty cause knee over-constraint?

Alberto Grassi
Stefano Di Paolo Eng
Piero Agostinone
Gian Andrea Lucidi
Erika Pinelly
Marco Bontempi
Laura Bragonzoni
Stefano Zaffagnini
Italy
Summary
Data
Background
Lateral extra-articular tenodesis (LET) in the context of Anterior Cruciate Ligament (ACL) reconstruction are adopted to better control anterolateral knee instability in patients with high-grade pre-operative pivot-shift. However, several authors believe these procedures are harmful to knee cartilage since they cause lateral compartment over-constraint in daily life motion.
Hypothesis/Purpose
The first aim of the present study was to identify kinematical differences between ACL-reconstructed knees with anatomic SB and SB plus lateral plasty (SBLP) techniques during the execution of an active under weight-bearing activity. The secondary aim was to compare these post-surgery kinematical data to the ones of the same knees before ACL reconstruction and of healthy contralateral knees, in order to investigate if ACL surgery was able to restore physiological knee biomechanics during squat execution. The hypotheses were that I) SBLP technique allows a better restoration of internal-external knee rotation than SB and that II) ACL reconstruction does not fully restore physiological knee biomechanics regardless of the technique.
Methods
Thirty-two patients (42 knees) were included in the study and divided in ACL-injured (n=32), anatomical SB (n=9), SBLP (n=18), and healthy knee (n=10) groups. Patients were asked to perform a single leg squat before surgery and at minimum 18 months of follow up. Knee motion was determined using a validated model-based tracking process that matched subject-specific MRI bone models to dynamic biplane radiographic images, under the principles of Roentgen Stereophotogrammetric Analysis (RSA). Data processing was performed in a specific software developed in Matlab. Internal-External (IE), Varus-Valgus (VV) rotations, and Anterior-Posterior (AP) and Medio-Lateral (ML) translations were compared among the groups.
Results
No kinematical differences were found between SB and SBLP groups (p>0.05). A more tibial medial position (p<0.05) of the ACL-injured group was during the entire motor task and also persisted after ACL when compared to the healthy group. Differences in IE and VV were found between Injured ACL and healthy groups.
Conclusion
The absence of rotational differences between techniques excluded the existence of knee over-constraint in the presence of an SBLP procedure during the execution of a single leg squat. Nonetheless, ACL reconstruction failed in restoring knee biomechanics regardless of the surgical technique.
Knee
ACL
Anterolateral Ligament
Ligaments
Repair/Reconstruction
Tears
Biomechanics
MRI
X-ray

### 19446 Degenerative medial meniscus tear with a displaced flap into the meniscotibial recess and tibial peripheral reactive bone edema presents good results with arthroscopic surgical treatment

Camilo P Helito1
Paulo Helito1
Pedro N Giglio1
Tales Mollica Guimarães1
José R Pécora1
Riccardo Gomes Gobbi1
Marcelo Bordalo-Rodrigues1
Bruno Vande Berg2
1Brazil
2Belgium
Summary
Arthroscopic surgical treatment of degenerative medial meniscal tears with a meniscal flap displaced into the meniscotibial recess and adjacent focal bone edema in the tibia shows good results in approximately 80% of cases. Smoking and KL grade 2 were associated with poor prognosis. The treatment of such lesions should be considered separately from the spectrum of degenerative meniscus lesions
Data
Purpose
To report the arthroscopic treatment results of a degenerative medial meniscus tear with a displaced flap into the meniscotibial recess, tibial peripheral reactive bone edema and focal knee medial pain.
Methods
From 2012 to 2018 patients who had this specific meniscus pathology that underwent arthroscopic surgical treatment were retrospectively evaluated. Patients with diffuse pain, previous knee surgeries, inflammatory diseases, concomitant surgical procedures and Kellgren- Lawrence (KL) classification greater than 2 were excluded. Patient demographic data, KL classification, the presence of an Outerbridge grade III or IV chondral lesion of the medial compartment, limb alignment, body mass index (BMI), and smoking were evaluated. The subjective outcomes included the International Knee Documentation Committee (IKDC) score, improvement in the pain reported by patients, and the Global Perceived Effect (GPE) scale score.
Results
A total of 69 patients were evaluated. The mean age was 58.6 ± 7.1 years. The follow-up time was 48.7 ± 20.8 months. Fifty-five (79.7%) patients reported pain improvement. The postoperative IKDC was 62.6 ± 15.4, and the mean GPE was 2.3 ± 2.6. Fourteen patients (20.3%) showed no improvement in pain and seven patients (10.2%) presented complications. Groups that improved (GPE >0) and not improved (GPE<0) did not present differences regarding age, sex, follow-up time, chondral lesions, or BMI. Patients without improvement had a higher incidence of smoking (p=0.001), varus alignment (p=0.008), and more advanced KL classification (p< 0.001). In the multivariate analysis based on the GPE score, KL classification (p=0.038) and smoking (p=0.003) were significant.
Conclusion
Arthroscopic surgical treatment of degenerative meniscal tears with a meniscal flap displaced into the meniscotibial recess and adjacent focal bone edema in the tibia shows good results in approximately 80% of cases. Smoking and KL grade 2 were factors associated with poor prognosis of surgical treatment. Level of evidence: Level IV (case series)
Knee
Arthroscopy
Meniscus
Tears
Aedema
Arthritis
Bones
Cartilage
Cartilage Injuries
Medial
MRI
Outcome Studies

### 19598 Is surgical treatment an advantage when treating acute AC joint dislocation type III and V? A prospective randomized clinical trial

Helena Boström Windhamre
Johan von Heideken
Wilhelmina Ekström
Anders Ekelund
Sweden
Summary
No longterm difference in clinical outcome in patients with acute AC joint dislocation Rockwood type III and V treated with physiotherapy or surgery
Data
Aim
To evaluate outcome after surgery and conservative treatment of acute acromioclavicular joint dislocation Rockwood type III and V
Background
Acromioclavicular joint (AC joint) dislocation is a common injury among sport-active young to middle-aged people. AC joint dislocations Rockwood type I and II are treated conservatively. Treatment of grade III is controversial, while surgery is often recommended for grade V.
Methods
A prospective randomized clinical trial comparing the results after surgery or conservative treatment of acute Rockwood type III and V dislocation was performed. Patients aged 18–65 years were included after classification of the AC-joint dislocation on plain radiographs of both shoulders, information and written consent. Patients were randomized to surgical treatment with hook plate within 3 weeks after injury, or physiotherapy. The hook plate was routinely removed after 3 months. Clinical follow-up was performed at 3, 6, 12 and 24 months by an orthopedic surgeon and a blinded physiotherapist. Primary outcome was Constant score (CS). Secondary outcomes were Subjective Shoulder Value (SSV), QuickDASH, shoulder pain at rest and during activity on a Visual Analogue Scale 0-10, EQ5D and adverse events. Radiographic follow up with plain radiographs was performed at 24 months. Statistical data analysis was performed by an unbiased evaluator and data was analyzed by intention-to-treat (ITT).
Results
124 patients were enrolled and randomized in the study; 114 men and 10 women with a mean age of 40 years (range 18–64). At 1 month patients treated without surgery had significantely better EQ-5D index. At 3 months patients treated conservatively had significant better CS compared to patients treated with surgery (Rockwood III 81 vs 57, Rockwood V 84 vs 64, p<0.001) as well as significantly less pain during movement on a VAS scale compared to patients treated with surgery (Rockwood type III 1.5 vs 2.8, Rockwood V 1.5 vs 2, p=0.002). SSV at 3 months was significantly better for the conservatively treated patients (Rockwood III 73 vs 50, Rockwood V 73 vs 57, p<0.001) as well as Quick-DASH (Rockwood III 18 vs 34, Rockwood V 13 vs 32, p<0.001). Follow-up at 6, 12 and 24 months showed no significant difference between the groups. At 24 months CS for patients with Rockwood III and non-surgical treatment was 88 vs 91 after surgical treatment and for Rockwood V CS was 90 for non-surgical treatment vs 91 after surgical treatment, p=0.477. Of the patients assigned to physiotherapy, 11 patients (18%, 6 type III and 5 type V), chose to have secondary surgery within 19 months (range 6–19).
Conclusion
Both treatments groups had very good restoration of shoulder function at 24 months, and operative treatment did not lead to better outcome compared to conservative treatment. In conclusion, our study did not support surgery with hook plate for patients with acute AC joint dislocation Rockwood type III or V.
Shoulder
Acromio Clavicular
Dislocation
Implant
Acromioclavicular Ligaments
Coracoacromial Ligaments
Instability
Ligaments
Outcome Studies
Physical Examination
Repair/Reconstruction
X-ray

### 19649 Postoperative MRI demonstrates a high rate of healing but worsening meniscus extrusion following transtibial root repair: a prospective multi-center study

Aaron J Krych
Richard F Nauert
Bryant M Song
Ryan R Wilbur
Corey S Cook
Patrick A Smith
Michael J Stuart
USA
Summary
We documented a high rate of meniscal healing and no progression of cartilage degeneration and subchondral bone abnormalities with short-term MRI follow-up; however, there was worsening of meniscus extrusion, even in the immediate post-operative period.
Data
Background
Prospective studies evaluating second look imaging of meniscus root repair using a transtibial pullout technique are limited; therefore, optimal surgical indications and technique for meniscus root repair remain uncertain.
Hypothesis/Purpose
We hypothesized a high rate of healing, improvement in meniscus extrusion and prevention of articular cartilage degeneration and subchondral bone abnormalities following meniscus root repair. Study Design: Prospective cohort study; Level of evidence, 3.
Methods
Consecutive patients undergoing transtibial root repair were prospectively enrolled at two orthopedic centers between March 2017 and January 2019. Pre- and post-operative MRIs were reviewed by a musculoskeletal radiologist in a blinded fashion for meniscus healing, quantification of extrusion, articular cartilage grade, subchondral bone changes, and coronary/meniscotibial ligament abnormalities. Given persistent extrusion observed on post-operative MRIs, an additional 10 patients were consented and enrolled for immediate (before weight-bearing) post-operative MRIs.
Results
45 patients (16 M: 29F) with an average age of 42.3 (SD 12.9) and BMI of 31.6 who underwent 47 meniscal root repairs (29 medial, 16 lateral, 2 had both) were prospectively enrolled in the study. Post-operative MRI was obtained on average 6.3 months following surgery (range 5.1–8 months). 98% of meniscus repairs had evidence of healing. Mean extrusion increased from an average of 1.94 mm (± 1.52) pre-operatively to 2.62 mm (± 1.44) post-operatively (p = 0.03). There was no significant progression of chondromalacia grade, subchondral edema, insufficiency fracture, subchondral cysts, or subchondral collapse. In the additional 10 patient cohort, the mean pre-operative extrusion increased from 1.64 mm (± 1.19) to 2.0 mm (± 0.98) post-operatively (p=0.23).
Conclusions
Prospective MRI analysis of transtibial meniscus root repair confirms a high rate of meniscal healing and no observable progression of cartilage degeneration or subchondral bone abnormalities at short-term follow-up. However, meniscus extrusion worsens, even in the immediate post-operative period. Additional studies should evaluate techniques to improve meniscus extrusionare warranted to optimize meniscal root fixation techniques to decrease post-operative meniscal extrusion. Keywords: meniscus; meniscus root; meniscus extrusion; meniscal tear; transtibial pullout repair; prospective cohort
Knee
Arthroscopy
Meniscus
Tears
Lateral
Medial
MRI
Repair/Reconstruction
X-ray

### 19448 Proximal and mid-thigh fascia lata graft constructs used for arthroscopic superior capsular reconstruction show equivalent biomechanical properties. An in vitro human cadaver study

Clara Azevedo
Catarina Ângelo
Carlos Quental
Sérgio Gonçalves
Nuno Vieira Ferreira
Nuno Sevivas
Portugal
Summary
The proximal fascia lata (PFL) graft used for arthroscopic superior capsular reconstruction is openly harvested, whereas the mid-thigh (MFL) graft is minimally invasively harvested. The purpose of this study was to compare their biomechanical properties. We hypothesized that, despite their different morphological characteristics, their biomechanical properties would not significantly differ.
Data
Background
The proximal fascia lata graft construct (PFL) used for arthroscopic superior capsular reconstruction (ASCR) is openly harvested, whereas the mid-thigh fascia lata graft construct (MFL) is minimally invasively harvested. Knowledge of how the MFL compares biomechanically with the PFL may assist orthopedic surgeons in the choice of the location, harvesting technique, and type of graft construct for ASCR. The purpose of the current study was to compare the biomechanical properties of PFLs and MFLs used for ASCR. The hypothesis was that, despite the different morphological characteristics of the PFL and MFL used for ASCR, their biomechanical properties would not significantly differ.
Methods
Forty fascia lata (FL) specimens, twenty proximal-thigh and twenty mid-thigh, were harvested from the lateral thighs of ten fresh human cadavers (6 male, 4 female; average age, 58.60±17.20 years). The thickness of each 2-layered proximal- and 6-layered mid-thigh FL final graft construct was measured. Each construct was mechanically tested in the longitudinal direction, and the stiffness and Young’s modulus (YM) were computed. Data were compared by Welch’s independent t-test and analysis of variance. Statistical significance was set at P < 0.05.
Results
The average thickness of the PFL (7.17±1.97 mm) was significantly higher than that of the MFL (5.54±1.37 mm) [F (1,32)=7.333, p =0.011]. The average YM of the PFL and MFL was 32.85±19.54 MPa (range, 7.94–75.14 MPa; 95% CI, 23.71–42.99) and 44.02±31.29 MPa (range, 12.53–120.33 MPa; 95% CI, 29.38–58.66), respectively. The average stiffness of the PFL and MFL was 488.96±267.80 N/mm (range, 152.96–1086.49 N/mm; 95% CI, 363.63–614.30) and 562.39±294.76 N/mm (range, 77.46–1229.68 N/mm; 95% CI, 424.44–700.34), respectively. There was no significant difference in the average YM or stiffness between the PFL and MFL (p=0.185 and p =0.415, respectively). The main findings of this study were that the average values of the stiffness and YM did not significantly differ between the two types of FL graft constructs, despite the greater average thickness of the PFL. This study has several strengths: the PFL and MFL groups were equally sized with regard to the sex and age of the subjects, thereby avoiding the confounding influence of the sex- and age-dependent morphological and mechanical properties of the FL on the results; and the specimens were harvested from fresh cadavers, avoiding the significant influence of the fixation methods used to preserve fresh-frozen or embalmed cadaveric specimens on the mechanical properties of the FL. This study validates the biomechanical equivalence of the two types of FL graft constructs with regard to the stiffness and YM, and orthopedic surgeons and patients may find the mid-thigh harvesting of the graft advantageous versus the open harvesting technique because the MFL can be minimally invasively harvested using a reproducible technique, with a low donor site morbidity. This study defines material properties of PFLs and MFLs that can be used in computational studies regarding the role of the FL graft in ASCR.
Conclusion
Despite the different morphological characteristics of the PFL and MFL used for ASCR, their YM and stiffness did not significantly differ.
Shoulder
Autograft
Glenohumeral
Tears
Arthroscopy
Basic Science
Biomechanics
Elderly
Infraespinatus Tendon Injury
Repair/Reconstruction
Supraespinoatus Tendon Injury
Tendon

### 19395 Quadriceps tendon autograft has lower MRI signal than hamstring tendon autograft in anterior cruciate ligament reconstructions of adolescent athletes

David Alcoloumbre
Alexandra H Aitchison
Douglas Mintz
Frank A Cordasco
Daniel W Green
USA
Summary
Quadriceps tendon autograft may have a superior rate of incorporation and synovialization as compared to hamstring tendon autograft
Data
Purpose
Hamstring tendon autograft (HTA) is a common graft choice for anterior cruciate ligament (ACL) reconstructions in skeletally immature patients. However, quadriceps tendon autografts (QTA) have recently shown superior preliminary outcomes in this population. The purpose of this study was to evaluate graft maturity by comparing MRI signal intensity of HTA and QTA used in primary ACL reconstruction. Given the promising preliminary results of QTA reconstructions in our center, we hypothesized that QTA would have lower signal than HTA at both 6 and 12 months.
Methods
Patients under the age of 18 who underwent a primary ACL reconstruction between 2011 and 2018 by the senior authors using either a HTA or QTA with available MRIs at 6 and 12 months post-operatively were included. Signal intensity ratio (SIR) was measured on sagittal MRI by averaging the signal at three regions of interest (ROIs) along the ACL graft and dividing each by the signal of the tibial footprint of the PCL. Statistical analysis was performed to determine interrater reliability and differences between time points and groups.
Results
71 patients (38 in the HTA group and 33 in the QTA group) were reviewed retrospectively. Age, sex, and type of surgery were not different between groups. There was no significant difference in SIR between groups on the 6-month MRI. At 12 months, SIR of the QTA group was significantly less that in the HTA group (p=.029). Within the HTA group, there was no significant difference in SIR between time points. In the QTA group, there was a significant decrease in SIR between the 6 month and 12-month post-operative MRI (p=.045).
Conclusion
The decrease in signal between 6 and 12 months post-operatively suggests quicker graft maturation and improved structural integrity of QTA as compared to HTA.
Knee
ACL
Autograft
Instability
Ligaments
MRI
Outcome Studies
Repair/Reconstruction

### 19707 Strength of elbow flexion and forearm supination after long head biceps treatment during rotator cuff repair

Shin Yokoya
Yasuhiko Sumimoto
Japan
Summary
We compared the postoperative muscle strength ratio of elbow flexion and forearm supination in cases with differing long head of biceps tendon (LHBT) procedures during rotator cuff repair. There was no significant difference between the control, tenotomy, and tenodesis groups, suggesting that the presence of LHBT lesion and the difference in treatment methods have little effect on muscle strength.
Data
Introduction
The effect of tenotomy or tenodesis of the long head of the biceps tendon (LHBT) during rotator cuff repair on biceps muscle strength is not well understood. In assessing muscle strength, preoperative muscle strength could be affected by pre-operative pain or cuff tear, therefore the post-operative muscle strength ratio of the affected and contralateral side is calculated. However, previous reports have not been able to eliminate the effects of the presence of rotator cuff tears on the healthy side or of cuff re-tear on the affected side. In this study, we only focused on cases with good rotator cuff healing on the affected side and with no cuff tears on the unaffected side, in order to examine the effect of the LHBT treatment on muscle strength.
Methods
This study comprised 104 patients (53 males and 51 females, mean age 65.7 ± 9.1 years) who underwent rotator cuff repair, and had good healing of rotator cuff (Sugaya classifications I and II) on MRI two years postoperatively, and had no complaints and no rotator cuff tears on ultrasonographic evaluation in contralateral side were enrolled. Two years postoperatively, we compared the ratio of elbow flexion strength and forearm supination strength on the affected side to that on the normal side at in the following groups: The control group, comprising 59 patients with normal LHBT and preserved LHBT intraoperatively; the tenotomy group, comprising 27 patients with a pathological lesion of LHBT treated by simple tenotomy; and the tenodesis group, comprising 18 patients with pathological lesion of LHBT treated by tenodesis using interference screw. In addition, we also evaluated the presence of Popeye’s deformity and cramping pain.
Results
The strength ratios of elbow flexion and forearm supination of the affected side to the healthy side were 0.96 ± 0.16 and 0.98 ± 0.26 in the control group; 0.92 ± 0.23 and 0.85 ± 0.20 in the tenotomy group; and 0.95 ± 0.12 and 0.98 ± 0.22 in the tenodesis group, with no significant difference between the three groups (p=0.71 and p=0.08). There were 0 cases with Popeye’s deformity and upper arm spasm in the control group; 2 (7.4%) and 5 (18.5%) cases in the tenotomy group; and 1 (5.6%) and 1 (5.6%) case in the tenodesis group, respectively.
Conclusion
Some previous studies compared the muscle strength of biceps between tenotomy and tenodesis of LHBT, but the results were controversial. In the present study, the strength ratio of elbow flexion and forearm supination remained the same in both the tenotomy and tenodesis groups, even when cases without LHBT lesions were included in the comparison, suggesting that the presence or absence of LHBT lesions and the difference in treatment methods have little effect on muscle strength.
Shoulder
Arthroscopy
Glenohumeral
Tears
Elderly
MRI
Tendon

### 19703 Pre-operative tunnel widening does not significantly influence the outcomes of a single-stage only approach to revision acl reconstruction: an analysis of 409 consecutive patients

Charles Pioger2
Johnny Rayes3
Ibrahim Haidar2
Cédric Ngbilo4
Thais Dutra Vieira5
Etienne Cavaignac2
Bertrand Sonnery-Cottet2
1USA
2France
4Switzerland
5Brazil
Summary
A single-stage approach to revision ACL reconstruction is associated with excellent clinical results when an outside-in drilling technique is utilized. The presence of pre-operative tunnel widening does not significantly influence patient reported outcome measures, knee stability, graft rupture rates or non-graft rupture related re-operation rates.
Data
Introduction
Pre-operative tunnel widening is a frequently reported indication for performing a two-stage revision anterior cruciate ligament reconstruction (R-ACLR) instead of a single-stage procedure. However, the strength of the available evidence to support a two-stage strategy is low. The main purpose of this study was to evaluate the clinical outcomes of a single-stage only approach to R-ACLR. It was hypothesized that this approach would be associated with significant improvements from baseline in patient reported outcome measures (PROMS) and knee stability, and also that there would be no significant differences in any post-operative outcomes between patients with and without pre-operative tunnel widening.
Methods
A retrospective analysis of a large series of consecutive patients undergoing R-ACLR, with a minimum follow-up of two years, was conducted. Pre-operative tunnel widening was assessed using digital radiographs. All patients underwent single-stage surgery, with an outside-in technique, even if they had tunnel widening. Clinical outcomes were compared according to whether tunnel widening was present (either tunnel = 12 mm) or not (both tunnels <12 mm). Comparisons between variables were assessed with the Chi-square or Fisher’s exact tests for categorical variables and the Student’s t test or Wilcoxon test for quantitative variables.
Results
409 consecutive patients with a mean follow-up of 69.6 ± 29.0 months were included in the study. At two years following R-ACLR, there was a significant reduction in the side-to-side AP laxity difference from 7.7 ± 2.2 mm pre-operatively to 1.2 ± 1.1 mm (p < .001). The mean IKDC and all KOOS subscales exceeded the patient acceptable symptom state (PASS) thresholds defined for primary ACLR. There were no significant differences between groups with respect to antero-posterior side-to side laxity difference, graft rupture rates, non-graft rupture related re-operations, or contralateral ACL injury rates. There was also no significant difference between groups, exceeding minimal detectable change thresholds, for any of the PROMS recorded (ACL-RSI, Lysholm, Tegner, IKDC, KOOS).
Conclusions
A single-stage approach to revision ACL reconstruction is associated with excellent clinical results when an outside-in drilling technique is utilized. The mean IKDC and all KOOS subscales exceeded the patient acceptable symptom state (PASS) thresholds defined for primary ACLR. The presence of pre-operative tunnel widening did not significantly influence PROMS, knee stability, graft rupture rates or non-graft rupture related re-operation rates. This suggests that two-stage R-ACLR is rarely warranted.
Knee
ACL
Arthroscopy
Instability
Ligaments
Evidence Based Medicine
Failed
MRI
Outcome Studies
Repair/Reconstruction
X-ray

### 19480 Combined ACL and anterolateral ligament reconstruction confers significantly improved long term outcomes when compared to isolated ACL reconstruction: a matched-pair analysis

Ibrahim Haidar2
Johnny Rayes3
Cédric Ngbilo4
Benjamin Freychet2
Thais Dutra Vieira5
Herve Ouanezar6
Bertrand Sonnery-Cottet2
1USA
2France
4Switzerland
5Brazil
6United Arab Emirates
Summary
Patients who undergo combined ACL and anterolateral ligament reconstruction experience significantly better long-term ACL graft survivorship, a five-fold lower risk of graft rupture, lower overall rates of re-operation, and no increase in complications when compared to those who undergo isolated ACL reconstruction
Data
Introduction
Recent clinical studies have demonstrated significant advantages of combined anterior cruciate ligament and anterolateral ligament reconstruction (ACL+ALLR) over isolated ACL reconstruction (ACLR) with respect to reduced graft rupture rates, a lower risk of re-operation for secondary meniscectomy, improved knee stability, and higher rates of return to pre-injury levels of sport. However, due to the relative infancy of this procedure, long term studies have not yet been published, and it remains to be seen whether the reported advantages of the combined procedure are maintained at long term follow-up. The primary objective of this study was to compare the long-term clinical outcomes of isolated ACLR versus combined ACL+ALLR. The hypothesis was that patients who underwent combined procedures would experience significantly lower ACL graft rupture rates at long term follow-up than their matched counterparts who underwent isolated ACLR.
Methods
Patients undergoing primary ACL+ALLR between January 2011 and March 2012 were propensity matched in a 1:1 ratio to patients who had undergone isolated ACL reconstruction during the same period. Face-to-face post-operative follow-up was undertaken at 3 and 6 weeks, and 3, 6, 12 and 24 months. Due to the geographically mobile nature of young populations (particularly notable at long-term follow up), and the impact of COVID-19, the final follow up was conducted using a standardized telemedicine interview (between April and May 2020), completion of PROMs questionnaires and review of medical notes. The telemedicine interview and notes review sought to determine whether patients had sustained a further ipsilateral knee injury, had experienced any symptoms of knee instability or stiffness, or had undergone any re-operations or complications. As a result of these follow-up arrangements, physical examination findings (range of motion and knee stability) are reported at two-years follow up. Complications, re-operations and outcome measures including Lysholm, Tegner, IKDC and KOOS are reported at the final follow-up. Graft survivorship was assessed using Kaplan-Meier analysis. Logistic regression was performed in order to account for the potential impact of activity level on graft rupture rates.
Results
86 matched pairs were included in the study. The mean duration of follow-up was 104.33±3.84 months (range 97–111 months). Patients who underwent combined ACL+ALLR experienced significantly better ACL graft survivorship (96.5% vs 82.6%, p=0.0027), lower overall rates of re-operation (15.3% vs 32.6%, p<0.05), lower rates of revision ACLR (3.5% vs 17.4%, p<0.05), and no increase in complications, when compared to those who underwent isolated ACLR. Patients undergoing isolated ACLR were at more than five-fold greater risk of graft rupture (OR, 5.549; 95%CI 1.431 to 21.511, p = 0.0132), regardless of their pre-injury activity level.
Conclusion
Patients who undergo combined ACL and anterolateral ligament reconstruction experience significantly better long-term ACL graft survivorship, lower overall rates of re-operation, and no increase in complications when compared to those who undergo isolated ACLR. In contrast, patients undergoing isolated ACLR had a greater than five-fold increased risk of undergoing revision surgery at a mean follow-up of 104.3 months.
Knee
Anterolateral Ligament
Ligaments
Repair/Reconstruction
Tears
ACL
Arthroscopy
Autograft
Capsuloligamentous Complex
MRI
Outcome Studies
Physical Examination
Single Bundle

### 19600 Arthroscopic treatment for anterolateral impingement of the ankle: systematic review and exploration of evidence about role of ankle instability

Mai Katakura1
Haruki Odagiri2
James D Calder1
Stéphane Guillo3
1UK
2Japan
3France
Summary
This systematic review reports good clinical results of arthroscopic debridement for chronic ankle anterolateral impingement but all papers had a low level of evidence and intraoperative observation of the ATFL and documentation of residual instability after surgery was lacking.
Data
Background
Chronic anterolateral pain is a frequent complaint after an inversion ankle sprain and soft tissue anterolateral impingement (ALI) of the ankle can be the cause of this symptom. Arthroscopic debridement is a common surgical treatment for patients with ALI of the ankle. This procedure is widely accepted, however, some cases with residual feeling of instability or new inversion injury after surgery have also been reported. Although a history of ankle sprain is commonplace, information regarding the role of ankle instability in ALI is limited. The aims of this review were to (1) assess the clinical outcomes of arthroscopic surgical treatment for ALI of the ankle and (2) review the data regarding anterior talofibular ligament (ATFL) injury and lateral ankle instability in patients who underwent arthroscopic surgery for ALI. Method: A literature search of Pubmed and EMBASE were performed. Studies that met the following inclusion criteria were reviewed by two independent investigators: (1) human clinical studies investigating patients who underwent arthroscopic surgery for ALI; (2) results with at least one scoring system with minimum follow-up of six months. Exclusion criteria were: (1) review articles or case reports; (2) not written in English; (3) included patients with objective ankle instability; (4) included patients with previous injuries other than ankle sprains in the ipsilateral ankle. The quality of each study was evaluated using the Oxford CEBM tool to assess the level of evidence and the grade of recommendation. The data of patient characteristics, follow-up period, intra-operative findings of ATFL and anterior inferior tibiofibular ligament (AITFL) and clinical outcomes were extracted.
Results
The electronic database search yielded 192 studies. Of these, 8 articles were included in this systematic review, all of which were graded level 4 with grade C recommendation. In total, 203 patients with a mean age of 32 years (ranging from 11 to 74) were analysed. The mean follow-up period was 36 months (range, 12 - 152 months). AOFAS score was used in 6 studies and scored 90.1 on average at follow-up. Two other studies used original scores. One study reported arthroscopic findings of the ATFL with damage to the ATFL observed in 20 out of 24 cases. AITFL impingement was mentioned in 3 studies, with the rate of AITFL impingement reported from 19.5–25.0%. Another study reported residual instability after surgery in 2 out of 31 patients. New ankle sprains during follow-up period were reported in 8.3–20.0% of patients in 4 studies.
Conclusion
This review showed good clinical results of arthroscopic debridement for ALI but all papers were graded level 4 with grade C recommendation. Reports regarding arthroscopic observation of the ATFL and residual instability after surgery were lacking. Further investigation of what is frequently termed “ALI” should be made with higher level of evidence focusing more on ATFL injury and its effect on clinical outcomes.
Ankle/Foot/Calf
Arthroscopy
Impingement
Ligaments
Anterior Talofibrilar Ligament
Anterior Tibiofibular Ligament

### 19623 Defining critical glenoid bone loss in posterior shoulder capsulolabral repair

Justin W Arner1
Joseph J Ruzbarsky1
Kaare Midtgaard2
Liam A Peebles1
Matthew T Provencher1
1USA
2Norway
Summary
Risk factors for failure of arthroscopic posterior shoulder capsulolabral repair include smaller glenoid bone width and greater glenoid bone loss percentage. A threshold of 11% posterior glenoid bone loss implicated a 10 times higher surgical failure rate while a threshold of 15% lead to a 25 times higher surgical failure rate.
Data
Background
Although critical bone loss for anterior instability is well defined, a clinically significant threshold of posterior bone loss has not been elucidated.
Hypothesis
Patients who fail arthroscopic posterior shoulder capsulolabral repair will have increased posterior glenoid bone loss with a defined critical threshold.
Study Design: Case-Control Methods
Athletes greater than 18 years of age with unidirectional posterior instability treated with arthroscopic repair were evaluated at 2 year minimum follow-up. Failure was defined as revision surgery, ASES <60, or subjective stability score >5. MRIs measurements from 19 patients who failed arthroscopic posterior shoulder capsulolabral repair were compared with 56 patients who did not. MRIs measures included glenoid version, labral version, glenoid width, labral width, percent bone loss using the circle technique, labral height, percent subluxation, and recently described measures of defect slope, bone loss angle, and defect length. The p-value threshold was set at 0.05 and a multivariable logistic regression analysis was performed for evaluation of risk of surgical failure.
Results
Smaller glenoid width and greater percent glenoid bone loss (25.5 + 0.68 mm vs 28.8 + 0.47 mm, p<0.001; 6.8 + 0.64% vs 4.6 + 0.43%, p=0.008) was seen in those that failed surgery. There was no difference in glenoid version or other measurements between the failures and non-failures. A cutoff of 11% glenoid bone loss resulted in a 10 times statistically higher surgical failure rate, while 15% bone loss resulted in a 25 times statistically higher failure rate. Six patients had bone loss greater than 11% (range, 11.1 - 19.3) and 1 patient had greater than 15% bone loss.
Conclusion
Risk factors for failure of arthroscopic posterior shoulder capsulolabral repair include smaller glenoid bone width and greater glenoid bone loss percentage. A threshold of 11% posterior glenoid bone loss implicated a 10 times higher surgical failure rate while a threshold of 15% lead to a 25 times higher surgical failure rate. Surgical failure of posterior capsulolabral repair, however, is relatively rare as it is an overall successful intervention.
Shoulder
Glenohumeral
Instability
Repair/Reconstruction
Arthro-MRI
Inferior Glenohumeral Ligament
Labrum
Ligaments

### 19624 Characterization of hill-sachs lesions based on location, orientation, and volume: a 3-dimensional modeling study of 100 anterior shoulder instability patients

Justin W Arner
Petar Golijanin
Liam A Peebles
Brenton Douglass
Matthew T Provencher
USA
Summary
As it has been established that more medialized lesions have poorer clinical outcomes, this study highlights other HS parameters which are strongly associated with these more difficult lesions and therefore should be considered during evaluation.
Data
Purpose
To qualitatively and quantitatively describe advanced imaging characteristics of Hill-Sachs lesions (HSL) in a cohort of anterior shoulder instability patients using 3-dimensional (3-D) modeling software and (2) assess the impact of various HSL parameters on the HSL location and orientation in a patient cohort with anterior shoulder instability.
Methods
A cohort of 100 recurrent anterior instability patients with evidence of HSL with a mean age of 27.2 years (range = 18 to 43 years) were evaluated. 3-D models of unilateral proximal humeri were reconstructed from CT scans and the volume, surface area (SA), width, and depth of identified HSLs were quantified along with their location (medial, superior, and inferior extent). Multiple angular orientation measures of HSLs were recorded, including Hill-Sachs rim [HSLr] and Hill-Sachs center [HSLc] angles in order to classify the level and location of potential engagement. Mann-Whitney test was run to assess the relationship between measured parameters.
Results
Larger HSL had greater HH SA loss (p=0.001), HSL width (p=0.001), were more medial (p=0.015), and more inferior (p=0.001). Additionally, more medial lesions had greater HSLr angles (p=0.001). The mean depth and width of identified HSLs were 3.3 mm (range = 1.2–7.1 mm) and 16.0 mm (range = 6.2–30.4 mm), respectively. The mean volume of the HSL was 449.2 mm3 (range = 62.0–1365.6 mm3). The medial border of the HSL extended to 17.2 ± 4.4 (range = 9.3 - 28.3 mm) off the most medial edge of the HH cartilage margin (medialization). The mean HSLr and HSLc were 29.3 ± 10.5° and 30.1 ± 11.2°, respectively.
Conclusion
This is the first large study to analyze various HS parameters and their associations amongst each other by utilizing high quality 3-D modeling. There was a statistically significant association between more medialized HSL lesions and HSL volume, width, angles, humeral head SA loss and distance from the most superior point of the HH. More medialized lesions tended to have larger volume, width, SA loss and angles while being located more inferior. As it has been established that more medialized lesions have poorer clinical outcomes, this study highlights other HS parameters which are strongly associated with these more difficult lesions and therefore should be considered during evaluation.
Shoulder
Glenohumeral
Instability
Repair/Reconstruction
Bones
CT-Scan

### 19752 The effect of knee rotation on the tibial-tubercle-trochlear-groove distance in patients with patellar instability: an analysis of Mri And Ct measurements

Jakob Ackermann
Julian Hasler
Dimitri Graf
Sandro Fucentese
Lazaros Vlachopoulos
Switzerland
Summary
The knee rotation angle is an independent, inversely correlated predictor of the difference between TTTG measured on MRI and CT in patients with patellar instability.
Data
Purpose
This study aimed to quantify the effect of lower limb rotational parameters on the difference in the tibial-tubercle-trochlear-groove (TTTG) distance when assessed with magnetic resonance imaging (MRI) and computed tomography (CT) in patients with patellar instability. It was hypothesized that an increased knee rotation angle significantly contributes to an underestimation of TTTG by MRI.
Methods
Forty patients with patellar instability who had undergone standard radiographs, MRI and CT scans were included in this retrospective study. A musculoskeletal radiologist assessed all imaging for TTTG, femoral and tibial rotation, knee rotation and flexion angle, and trochlear dysplasia. deltaTTTG was defined as the TTTG measured on MRI subtracted from the TTTG measured on CT. Statistical analysis determined the effect of these parameters on the calculated difference between TTTG, when measured on CT and MRI.
Results
Equal knee flexion in MRI and CT resulted in a deltaTTTG of 0.1 ± 0.3° compared to 4.0 ± 3.3° in patients with different knee flexion angles in both imaging acquisitions (p=0.036). The knee rotation angle measured on CT was negatively correlated with deltaTTTG (r=-0.365; p=0.002), while neither tibial nor femoral rotation showed any associations with TTTG (n.s.). Trochlear dysplasia did not show any significant correlation with deltaTTTG, regardless of classification by Dejour or Lippacher (n.s.). Both the CT knee rotation angle and the MRI knee flexion angle were independent predictors of deltaTTTG, yet with an opposing effect (knee rotation: 95% Confidence Interval (CI) for beta: −0.468 to −0.154, p<0.001; knee flexion 95% CI for beta: 0.292 to 0.587, p<0.001). Patients with a CT knee rotation angle >20° showed a deltaTTTG of −5.8 ± 4.0° (MRI overestimates TTTG) compared to 0.9 ± 4.1° deltaTTTG (MRI underestimates TTTG) in patients with <20° CT knee rotation angle.
Conclusion
The knee rotation angle is an independent, inversely correlated predictor of deltaTTTG, thus opposing the effect of knee flexion during MRI acquisition. Consequently, these results suggest that not only knee flexion but also knee rotation should be appreciated when assessing TTTG during patellar instability diagnostic evaluation as it can potentially lead to an overestimation of the TTTG distance on MRI.
Knee
Instability
Osteotomy
Patellofemoral
Acute Patella Dislocation
Biomechanics
CT-Scan
Dislocation
MRI
Recurrent Subluxation and Dislocation

### 19754 Autologous matrix-induced chondrogenesis (AMIC) with concomitant lateral ligament stabilization for osteochondral lesions of the talus in patients with ankle instability

Jakob Ackermann
Fabio A Casari
Christoph Germann
Lizzy Weigelt
Stephan Hermann Wirth
Arnd Viehöfer
Switzerland
Summary
Concurrently performed AMIC and LLS in patients with OLT and ankle instability results in a clinical outcome that is comparable to isolated AMIC if postoperative ankle stability is achieved.
Data
Background
Autologous matrix-induced chondrogenesis (AMIC) has shown to result in favorable clinical outcome in patients with osteochondral lesions of the talus (OLT). Yet, the influence of ankle instability on cartilage repair of the ankle has still to be determined. This study sought to compare the clinical and radiographic outcome in patients with and without concomitant lateral ligament stabilization (LLS) undergoing AMIC for the treatment of OLT. It was hypothesized that patients with concomitant LLS for the treatment of coexistent symptomatic ankle instability show comparable results to patients who underwent isolated AMIC for the treatment of OLT.
Methods
This study evaluated AMIC that were implanted in patients for the treatment of symptomatic OLT with and without concomitant ankle instability. Postoperative MRI, Tegner, AOFAS and Cumberland Ankle Instability Tool (CAIT) were obtained at a minimum follow-up of 2 years. A musculoskeletal radiologist scored all grafts according to the MOCART 1 and 2.0 scores. Patients were stratified into two groups based on whether they underwent concomitant LLS for ankle instability. Patients without LLS served as controls. Patients were matched 1:1 for BMI, lesion size, follow-up and age.
Results
Twenty-six patients that underwent AMIC with a mean follow-up of 4.2 ± 1.5 years were enrolled in this study (13 with and 13 without concomitant ankle instability). Patients’ mean age was 33.4 ± 12.7 years with a BMI averaging 26.2 ± 3.7. Patients with concomitant LLS showed worse clinical outcome measured by AOFAS (85.1 ± 14.4 vs. 96.3 ± 5.8, p=0.034) and Tegner (3.8 ± 1.1 vs. 4.4 ± 2.3, p=0.012). Postoperative CAIT and AOFAS scores significantly correlated in patients with concomitant LLS (r=0.766, p=0.002). A CAIT score of > 24 (no functional ankle instability) resulted in AOFAS scores comparable to scores in patients with isolated AMIC (90.1 ± 11.6 vs. 95.3 ± 6.6; p=0.442). No difference was seen between both groups regarding MOCART 1 and 2.0 scores (p=0.714 and p=0.371, respectively).
Conclusion
Concurrently performed AMIC and LLS in patients with OLT and ankle instability results in a clinical outcome that is comparable to isolated AMIC if postoperative ankle stability is achieved. Residual ankle instability, however, was associated with worse postoperative outcome highlighting the need for adequate stabilization of ankle instability in patients with OLT.
Ankle/Foot/Calf
Cartilage
Instability
Repair/Reconstruction
Anterior Talofibrilar Ligament
Biologics
Biomechanics
Calcaneo Fibular Ligament
Evidence Based Medicine
Ligaments
MRI
Osteoarthritis
Outcome Studies
Professional Athletes/Olympians
Sport Specific Injuries
Sutures/Knots/Anchors

### 19588 Dermal patch augmented versus standard rotator cuff repair: randomised controlled trial

Martyn Snow
UK
Summary
A human acellular dermal patch augmented cuff repair did not improve functional outcome or healing at 12 months post-surgery compared to standard double row rotator cuff repair.
Data
Aim
The aim of this study was to compare the patient reported outcome measures and cuff healing at 12 months between standard and augmented rotator cuff repair with human acellular dermal patch.
Background
Recurrent rotator cuff tear following repair has been reported in up to 60% of cases. Maximising mechanical repair through double row fixation has failed to significantly improve healing rates, consequently, there is focus on the biological enhancement of healing. Patch augmentation is one method to augment repair, however, there are very few comparative studies assessing their efficacy.
Methods
A randomised controlled trial was conducted over patients undergoing arthroscopic repair of rotator cuff tear measuring between 1–5 cm. Patients were excluded for associated osteoarthritis, irreparable tear, or significant subscapularis tear. A total of 63 patients were recruited to the study between 2016 - 2019. Twenty-three patients were excluded leaving 40 patients in the final study population. They were randomised to one of two groups: augmented (cuff repair with human acellular dermal patch) and standard (double-row arthroscopic cuff repair). Functional assessment was performed at 3, 6, 9, and 12 months post-surgery with rotator cuff healing quantified on MRI scan at 12 months using Sugaya’s classification. Functional outcome was assessed using American Shoulder and Elbow score (ASES), Quick Disability of Arm, Shoulder and Hand (Quick-DASH) score, Constant-Murley score and Western Ontario Rotator Cuff (WORC) index. Statistical analysis was performed with chi-square, paired and unpaired t-test to compare the outcomes between the two groups.
Results
The mean age was 65.75 years in the augmented group and 69.25 years in standard group. The male:female ratio was 11:9 in the augmented group and 12:8 in the standard group. There was no significant difference in age, gender, tear size, fatty infiltration and pre-operative clinical outcome measures (p < 0.05) between the two groups. The mean ASES, qDASH, Constant, and WORC improved from 36.6, 52.2, 31.6, and 32.6 pre-operatively to 79.6, 17.1, 83.9, and 77.4 at 12 months in augmented; and from 31.9, 50.9, 31.4, and 25.2 pre-operatively to 74.8, 20.1, 71.1, and 74.9 at 12 months post-operatively in the standard group (p < 0.05). There was no significant difference in one-year clinical outcome measures between the two groups (p > 0.05). Compared to control group, greater number of patients in the augmented group achieved outcome scores more than the value of minimum clinically important difference (MCID) in three of the outcome measures (ASES 90% vs 84.2%, qDASH 85% vs 73.7%, Constant 100% vs 72.7%, WORC 84.2% vs 90%, augmented vs standard respectively). On MRI, re-tear (Sugaya grade 4 and 5) was observed in 25% (4 of 18) in augmented and 27.7% (5 of 18) patients in standard group (p = 1.000). There was no difference in the 12-months post-operative Goutallier fatty infiltration grades between the two groups (p = 0.495). The progression of fatty infiltration grades on post-operative MRI as compared to pre-operative MRI was noted in 28.5% (2 of 7) in augmented and 50% (5 of 10) patients in standard group, although the difference was not statistically significant (p = 0.662).
Conclusions
A human acellular dermal patch augmented cuff repair did not improve or healing at 12 months post-surgery compared to standard double row rotator cuff repair, however there was a trend of better clinical outcome scores and lower progression of fatty infiltration (although, not statistically significant) in dermal patch group.
Shoulder
Glenohumeral
Repair/Reconstruction
Tears
MRI
Outcome Studies
Supraespinoatus Tendon Injury
Tendon

### 19757 Clinical outcomes of primary Acl reconstruction with tibial attachment preserving quadrupled hamstring graft: does graft size matter? – A prospective study with review of literature

Shaival Dalal
Ghislain N Aminake
Randy Guro
Amit P Chandratreya
Rahul Kotwal
UK
Cameroon
Summary
Primary ACL reconstruction using tibial attachment preserving quadrupled hamstring graft is a simple and reproducible technique with an extremely low failure and complication rate and that gives excellent clinical and functional outcomes, irrespective of the graft diameter.
Data
Introduction
Recent literature supports the preservation of tibial attachment of hamstring grafts to enhance ‘‘ligamentization’’ process and prevent the potential problems of a free graft such as pull-out or rupture in the early post-operative period. The aim of this study is to present our results of primary ACL reconstruction with preservation of the tibial attachment of the hamstring grafts along with loop-stitched quadrupled hamstring grafts fixed with suspensory fixation on the femoral side and an interference screw and a staple on the tibial side, and determine if the graft diameter influences the failure rate and patient-reported outcome scores. Methodology-Prospective single-surgeon case-series evaluating patients undergoing surgery by this technique. Patients were followed up clinically and using PROMS from NLR with EQ-5D, KOOS, IKDC and Tegner scores. Paired two-tailed student t-tests and ANOVA tests were employed for statistical analysis. Results- 64 cases (47 males, 17 females) with a mean BMI of 26.3 and mean age of 30.2 years were included. Mean graft length and diameter of quadrupled semitendinosus and gracilis tendons was 110 mm and 7.1 mm respectively. Mean interval from injury to surgery was 11.8 months. At a mean follow-up of 3 years, 80% (n=51) had complete peri-operative PROMS scores. Mean peri-operative EQ-5D VAS, EQ-5D Index, KOOS, IKDC and Tegner activity scores showed significant improvement (p<0.001). At latest follow-up, there was no difference in the improvement of PROMS with regards to the graft diameter. Graft re-rupture was seen in 1 (1.5%) patient. 45 patients had associated meniscal tear with 73.3% undergoing repair. 3 cases (4.6%) returned to theatre including, MUA for arthrofibrosis (n=1) and meniscal repair for recurrent medial meniscus tear (n=2). Conclusion- Primary ACL reconstruction using tibial attachment preserving quadrupled hamstring graft is a simple and reproducible technique with an extremely low failure and complication rate and that gives excellent clinical and functional outcomes, irrespective of the graft diameter. The natural tibial side insertion provides secure fixation and adds biology to the anatomic reconstruction.
Knee
ACL
Instability
Ligaments
Repair/Reconstruction
Arthroscopy
Autograft
MRI
Outcome Studies
Single Bundle

### 19398 Bristow versus latarjet in high-demand athletes with anterior shoulder instability: a prospective randomized comparison

Paulo S Belangero
Paulo Henrique Schmidt Lara
Leandro Masini Ribeiro
Eduardo A Figueiredo
Carlos V Andreoli
Alberto C Pochini
Benno Ejnisman
Ricardo Luiz Smith
Brazil
Summary
Bristow x Latarjet in high-demand athletes
Data
Background
Traumatic anterior shoulder instability is a common disease, especially in young athletes. The Latarjet and Bristow techniques are non-anatomical surgeries that involve the transfer of the coracoid process to the anterior border of the glenoid and are indicated in cases at a high risk for recurrence and in the presence of associated bone lesions. Studies have evaluated the recurrence and complications associated with these techniques, but they have important differences, and should not be considered synonymous. The objective of this study was to prospectively compare the Bristow and Latarjet techniques in high-demand athletes.
Hypothesis
Bristow and Latarjet techniques lead to similar results. Patients and methods: Thirty-seven athletes (41 shoulders; three athletes underwent bilateral surgery) with anterior recurrent dislocation of the shoulder that were surgically treated using the Bristow or Latarjet technique were prospectively analyzed according to range of motion, functional scores, sports return rate and complications. The inclusion criteria for this study were anterior shoulder instability, no history of a shoulder procedure, high demand sports participation (more than 7 hours/week), 10–20% glenoid bone erosion in computed tomography scans and at least 60 months of follow-up. The follow-up time was 5 years. The mean age was 26.4 years (range: 16–46 years).
Results
Elevation and lateral rotation (passive and active) achieved values in the final follow-up similar to those found in the preoperative period. The mean postoperative scores after five years were as follows: ASES, 79,1 (range: 66–95); ASORS, 77,8 (range: 60–100); WOSI, 52,6 (range: 18–77); and VAS, 1,88 (range: 0–6). All of the results presented statistical significance. We did not have any case of redislocation. However, seven (17%) patients presented positive apprehension test (Three (16%) patients in the Bristow and four (18%) in the Latarjet group). Our results showed two cases of graft reabsorption that needed surgery to screw removal (one in each group). Two cases of screw malpositioning (with the graft being intra articular). Both cases were in the Bristow group and were surgically revised in two weeks from initial surgery. Comparing both procedures we found no statistically significant difference in active external rotation and active elevation. We found a statistically significant difference in passive external rotation in favor of the Latarjet technique four weeks after surgery (Latarjet average: 29,1 degrees; Bristow average: 20,53 degrees; p=0,01). We also found a statistically significant difference in passive elevation in favor of the Latarjet technique eight weeks after the surgery (Latarjet average: 132,73 degrees; Bristow average: 120,21 degrees; p=0,04). We found no statistically significant difference between both techniques regarding the functional scores (ASES, ASORS and WOSI). Comparing both procedures regarding sports return and complications there was no statistically significant difference.
Conclusion
The Bristow and Latarjet techniques showed significant improvement in functional scores, a low complication rate, an absence of recurrence, a good return to sports rate, and preservation of the shoulder range of motion. The Latarjet technique showed better results in the initial range of motion, but in the last follow-up, both procedures yielded similar ranges of motion.
Shoulder
Autograft
Glenohumeral
Instability
Bones
CT-Scan
Dislocation
Female Athletes
Labrum
Professional Athletes/Olympians
Sport Specific Injuries
Sport Specific Population
X-ray

### 19699 The effect of osteochondroplasty on time to reoperation after arthroscopic management of femoroacetabular impingement

Jeffrey Kay
Nicole Simunovic
Olufemi R Ayeni
First Investigators
Summary
This randomized, time-to-event analysis with 27-months follow-up demonstrates that for adults between the ages of 18 and 50 with femoroacetabular impingement, arthroscopic osteochondroplasty is associated with a two and a half times lower hazard of reoperation at any point in time compared to arthroscopic lavage.
Data
Purpose
The purpose of this study was to assess and compare the effect of arthroscopic osteochondroplasty versus arthroscopic lavage without osteochondroplasty on the time to reoperation in adults aged 18 to 50 with femoroacetabular impingement (FAI) over 27-months post-operative using a time-to-event analysis.
Methods
Using the comprehensive dataset from the multinational Femoroacetabular Impingement Randomized Controlled Trial (FIRST), all reoperations were identified until 27-months post-operative. All included subjects were randomized to a treatment of arthroscopic osteochondroplasty or arthroscopic lavage without osteochondroplasty. The primary analysis was conducted using a Cox proportional-hazards model, with the percentage of patients with a reoperation analyzed in a time-to-event analysis as the outcome. The independent variable was the procedure (osteochondroplasty versus lavage), with age and impingement severity subtype explored as potential covariates. The results from the Cox model were expressed as a hazard ratio (HR), corresponding 95% confidence interval (CI), and the associated p-value. All tests were two-sided with an alpha level of 0.05.
Results
A total of 220 patients with FAI were first enrolled in the study. Six patients were later found to be ineligible resulting in 108 total patients included in the osteochondroplasty group and 106 in the lavage group. The mean age of the patients included in the study was 36.0 (SD=8.5) years. Overall, a total of 27 incident reoperations were identified within 27 months of follow-up for an incidence rate of 6.0 per 100 person years. Within the osteochondroplasty group, a total of 8 incident reoperations were identified for incidence rate of 3.4 per 100 person years. In the lavage group, a total of 19 incident reoperations were identified for an incidence rate of 8.7 per 100 person years. The hazard of reoperation for patients undergoing osteochondroplasty is 40% that of patients undergoing lavage (HR=0.40, 95% CI=0.17 to 0.91, p=0.029).
Conclusion
This randomized, time-to-event analysis demonstrates that for adults between the ages of 18 and 50 with FAI, arthroscopic osteochondroplasty is associated with a 2.5-fold decrease in the hazard of reoperation at any point in time compared to arthroscopic lavage.
Hip/Groin/Thigh
Impingement
Arthroscopy
Outcome Studies

### 19498 Bacterial contamination of irrigation fluid and suture material during ACL reconstruction and meniscus surgery

Benjamin Bartek
Tobias Winkler
Anja Garbe
Carsten Perka
Tobias M Jung
Germany
Summary
Irrigation fluid during arthroscopic surgery shows bacterial contamination that increases over time.
Data
PURPOSE Arthroscopic knee surgery uses irrigation fluid, which accumulates in a sterile reservoir during surgery. It has not yet been examined whether the irrigation fluid or suture material used during arthroscopic surgery show bacterial contamination. In the present study, we aimed to determine the time-dependent contamination rate and to clarify its relevance for postoperative infections. MATERIAL AND METHODS We included 155 patients in the study, who underwent reconstruction of the anterior cruciate ligament (ACL) in 58 cases, meniscal surgery in 63 cases and combined ACL reconstruction and meniscus repair in 34 cases. During arthroscopic surgery, samples of the pooled irrigation fluid were obtained from the sterile reservoir every 15 minutes and additionally suture material of ACL graft and meniscus repair was examined for bacterial colonization. All samples were sent for microbiologic analysis with an incubation time of 14 days. Postoperative follow-up examinations for clinical signs of infections were conducted after 6 weeks, 12 weeks and 12 months in our orthopaedic outpatient department. RESULTS The number of positive microbiological findings in the fluid samples increased over time and showed a strong statistical correlation with the duration of surgery (R2 = 0.81, p = 0.015). The contamination rate of suture and fixation material was 28.4% (n = 29). One infection (caused by Staphylococcus lugdunensis) was observed during follow-up examinations. CONCLUSION Contact with the fluid reservoirs should be avoided as the bacterial contamination rate of the pooled irrigation fluid increases over time. Additionally, we recommend repeated skin disinfection before the introduction of suture material or ACL grafts to the surgical site.
Knee
Arthroscopy

### 19503 Prospective study comparing leukocyte-poor platelet rich plasma combined with hyaluronic acid and autologous microfragmented adipose tissue in patients with early knee osteoarthritis

Ignacio Dallo1
Macarena Morales2
Alberto Gobbi2
1Spain
2Italy
Summary
The purpose of this study is to evaluate the clinical efficacy of repeated doses of Leucocyte-poor Platelet-rich Plasma combined with Hyaluronic Acid and single dose of Adipose Derived Mesenchymal Stem Cells injections. It was hypothesised that Adipose Derived Mesenchymal Stem Cells could be superior to Leucocyte-poor Platelet-rich Plasma + Hyaluronic Acid for the treatment of early knee Osteoarth
Data
Purpose
The purpose of this study is to evaluate the clinical efficacy of repeated doses of Leucocyte-poor Platelet-rich Plasma combined with Hyaluronic Acid and single dose of Adipose Derived Mesenchymal Stem Cells injections. It was hypothesised that Adipose Derived Mesenchymal Stem Cells could be superior to Leucocyte-poor Platelet-rich Plasma + Hyaluronic Acid for the treatment of early knee Osteoarthritis at 12 months follow-up.
Methods
Eighty knees in fifty patients (mean age: 61.3 years, range 40–80) with early knee osteoarthritis were allocated into two groups from November 2016 to December 2017. The group 1 composed of 40 knees were treated with three intra-articular injections (1 month apart) using autologous Leucocyte-poor Platelet Rich Plasma combined with Hyaluronic Acid and the group 2 composed of 40 knees were treated with a single dose of Adipose-derived Mesenchymal Stem Cell injection by supra-patellar approach. Outcomes were measured by PROMs Tegner, Marx, VAS, IKDC and KOOS.
Results
All patients in both groups lead to clinical and functional improvement at 6 and 12 months. However, there is statistical significance evidence in favor of ADMSCs (Lipogems) only for the case of Tegner and KOOS Symptoms at 6 months and for Tegner at 12 months of follow-up.
Conclusion
This study shows both groups lead to clinical and functional improvement at 6 and 12 months. ADMSCs (Lipogems) showed better clinical results in Tegner and KOOS Symptoms at 6 months and for Tegner at 12 months of follow-up. This finding will aid clinicians to analyse the cost versus benefit ratio and help them to formulate an algorithm when treating patients with early osteoarthritis.
Knee
Biologics
Cartilage
Osteoarthritis
Aedema
Backer’s Cyst
Bones
Bursa
Cartilage Injuries
Cartilage Treatment
Elderly
Evidence Based Medicine
MRI
Outcome Studies
Physical Examination
Prepatellar Bursa
Synovial
Synovitis
X-ray

### 19732 Glenosphere lateralization in reverse shoulder arthroplasty leads to better functional and clinical outcomes in rotator cuff arthropaty patients – a systematic review with meta-analysis

Joni L Soares Nunes
Guilherme França
João Espregueira-Mendes
Nuno Sevivas
Portugal
Summary
The RSA with a lateralized glenosphere implant improves active shoulder motion and clinical and functional outcomes in selected patients with rotator cuff arthropathy or pseudoparalysis. The clinical and functional outcomes after lateralized RSA seem comparable to those previously reported for Grammont design implants, but with the newsworthy lower rate of scapular notching.
Data
Background
The use of reverse shoulder arthroplasty (RSA) has been constantly increasing and indications have expanded for many diagnoses. Medialization of the centre of rotation is one of the causes of glenoid notching and poor range of motion improvement. A more lateralized RSA has been suggested either at the glenoid or humeral side, but lateralizing the RSA yields a greater moment arm, generating greater torque at the glenoid baseplate-bone interface, which creates apprehension about early loosening and failure The aim of this systematic review was to scope analyze the influence on the clinical and functional outcomes of reverse shoulder arthroplasty lateralized at the glenoid side in patients with rotator cuff arthropathy and/or pseudoparalysis.
Methods
A systematic review was performed according to guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Pubmed and EMBASE databases were searched up to January 31, 2020. We included studies that comprised male or female adults with rotator cuff arthropathy or pseudoparalysis with or without osteoarthritis and that the RSA procedure was performed with a lateralized design implant. We excluded studies with less than 10 patients, that comprised patients reporting fractures, instability or escape, infection, rheumatologic or neurologic diseases, patients with revision surgeries or failed shoulder arthroplasty, and studies reporting only revision arthroplasties or mixed population that did not sub grouped the primary RSA. The Methodological Index for Non-Randomize Studies (MINORS) was used to assess study methodological quality.
Results
We included 9 studies comprising 6 retrospective studies (level III) and 3 prospective case series (level IV). The mean MINORS score was 11.7 ± 4.3. In total, there were 1,813 patients (61% female) with a mean age of 72.2 ± 3 years (range, 43–95) that underwent RSA with a lateralized design. The most common indications included pseudoparalysis without osteoarthritis (n=362), rotator cuff arthropathy (n=265) and pseudopralysis with osteoarthritis (n=111). The mean follow-up was 40.3 months (range, 28–52 months). Active forward flexion, abduction, external rotation and internal rotation improved with a mean change of 47 to 82°, 43 to 80°, 8 to 39° and 0.6 to 2 points, respectively. Functional scores also improved from pre to postoperative assessment including the American Shoulder and Elbow (mean change, 20 to 50), Constant (mean change, 28 to 40), Simple Shoulder Test (mean change, 3 to 7) and visual analogue score (mean change, -2 to -5). Complication ranged from 0 to 20% and accounted 85 complications (29% aseptic loosening, 9% acromion fracture, 7% glenosphere dissociation, 6% instability, and 6% infection). Scapular notching from 0 to 30% and of those with scapular notching, 53% were grade I, 40% grade II, 7% grade III and 0% grade IV (Sirveaux-Nerot classification). Rate of patients undergoing revision shoulder arthroplasty varied from 0 to 13%.
Conclusion
The RSA with a lateralized glenosphere implant improves active shoulder motion and clinical and functional outcomes in selected patients with rotator cuff arthropathy or pseudoparalysis. These results seem comparable to those previously reported for Grammont design implants, but with the newsworthy lower rate of scapular notching.
Shoulder
Arthroplasty
Glenohumeral
Osteoarthritis
Biomechanics
Bones
MRI
Outcome Studies

### 19693 Female athletes demonstrate greater improvement in patient reported outcome scores and equal return to sport rates compared to males after hip arthroscopy a gender based matched comparison of high-level athletes

Andrew Jimenez
Rachel Glein
Kara Miecznikowski
Benjamin Saks
Hari Krishna Ankem
Payam William Sabetian
Benjamin G Domb
USA
Summary
Female Athletes Demonstrate Greater Improvement in Patient Reported Outcome Scores and Equal Return To Sport Rates Compared to Males
Data
Background
No studies have compared outcomes or return to sport between a matched cohort of male and female athletes with minimum 2-year follow-up.
Purpose
(1) To report minimum 2-year patient reported outcome scores (PROs) and return to sport for high-level female athletes undergoing hip arthroscopy for femoroacetabular impingement (FAI) and (2) to compare clinical results with a matched control group of high-level male athletes. Study Design: Cohort study; Level of evidence, 3.
Methods
Data on all high-level female athletes who underwent primary hip arthroscopy between March 2009 and July 2018. Patients were considered eligible if they underwent hip arthroscopy for FAI and participated in high school, collegiate, or professional athletics. Minimum 2-year PROs were collected for the modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), Hip Outcome Score-Sport Specific Subscale (HOS-SSS), visual analog scale (VAS) for pain, and return to sport (RTS) status. The percentage of patients achieving minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) for the mHHS, NAHS, and HOS-SSS were also recorded. These patients were propensity score matched in a 1:1 ratio to male high-level athletes undergoing primary hip arthroscopy for FAI.
Results
Seventy-three high-level female athletes were included with a mean follow-up of 65.1 ± 27.9 months. They demonstrated significant improvement from preoperative to latest follow-up for mHHS, NAHS, HOS-SSS, and VAS (P < .05). The rate of return to sport was 75.4%, and patients achieved PASS/MCID for mHHS, HOS-SSS, and NAHS at high rates. Female athletes received a greater percentage of capsular repair and iliopsoas fractional lengthening compared to male athletes (P < .001). When outcomes were compared to a propensity matched control group of male athletes, female athletes demonstrated significantly better magnitude of improvement (delta value) for mHHS, NAHS, and VAS (P < .05). Female athletes also achieved MCID for HOS-SSS and NAHS at higher rates than male athletes (P < .05). There was no difference in RTS rates between the two groups (P > .05).
Conclusion
High-level female athletes undergoing primary hip arthroscopy for FAI demonstrate significant improvement in PROs and high rates of return to play. Female athletes exhibit greater improvement in PROs (mHHS, NAHS, VAS) and achieve MCID (HOS-SSS, NAHS) at higher rates when compared to a matched group of male athletes.
Hip/Groin/Thigh
Arthroscopy
Instability
Gender Specific
Outcome Studies
Physical Examination
X-ray

### 19615 Achieving successful outcomes in high-level athletes with borderline hip dysplasia undergoing hip arthroscopy with capsular plication and labral preservation: a propensity matched controlled study

Andrew Jimenez
Peter Monahan
Kara Miecznikowski
Benjamin Saks
Hari Krishna Ankem
Payam William Sabetian
Ajay C Lall
Benjamin G Domb
USA
Summary
High-Level Athletes with Borderline Hip Dysplasia Outcomes
Data
Background
Return to sport (RTS) and patient-reported outcomes (PROs) after hip arthroscopy in athletes with borderline hip dysplasia (BD) has not been established.
Purpose
(1) To report minimum 2-year PROs and RTS rates in high-level athletes with BD 10 who underwent hip arthroscopy for labral pathology in the setting of microinstability and (2) to compare clinical results with a matched control group of athletes with normal acetabular coverage. Study Design: Cohort study; Level of evidence, 3.
Methods
Data were reviewed for surgeries performed between November 2012 and July 2018. Patients were considered eligible if they received a primary hip arthroscopy in the setting of borderline dysplasia [lateral center-edge angle (LCEA) 18–25°] and competed in high-school, collegiate, or professional sports. Inclusion criteria included preoperative and minimum 2-year follow-up scores for the modified Harris Hip Score (mHHS), Non-arthritis Hip Score (NAHS), Hip Outcome Score-Sport Specific Subscale (HOS-SSS), and visual analog scale for pain (VAS). BD athletes were matched to a control group of athletes with normal acetabular coverage (LCEA 25°- 40°).
Results
A total of 65 patients with BD were included in the study with a mean follow-up of 47.5 ± 20.4 months. Athletes with BD showed significant improvement in all outcome measures recorded, demonstrated high RTS rates (80.7%), and achieved PASS/MCID for mHHS at high rates (MCID: 86.2%, PASS: 90.8%). When compared to a propensity matched control group with normal acetabular coverage, capsular plication was performed more commonly in the BD athletes (P = .037). PROs, RTS rate, and PASS/MCID rates were similar between the BD and control groups (P > .05).
Conclusion
High-level athletes with BD who undergo primary hip arthroscopy for labral pathology in the setting of microinstability may expect favorable outcomes with capsular plication and labral preservation. These results were comparable to the control group of athletes with normal coverage
Orthopaedic Sports Medicine
Arthroscopy
Impingement
Outcome Studies
Capsuloligamentous Complex
Hip/Groin/Thigh
Labrum
Labrum Tears
Labrum Treatment
Physical Examination
Professional Athletes/Olympians
Sport Specific Population
X-ray

### 19762 Medium-term results of one-stage vs two-stage bilateral MPFL reconstruction for bilateral patellofemoral joint instability: a retrospective cohort study

Anindya Debnath1
Shaival Dalal2
Randy Guro2
Rahul Kotwal2
Amit P Chandratreya2
1India
2UK
Summary
Simultaneous bilateral MPFL reconstruction is a safe approach to treat bilateral patellofemoral instability.
Data
Introduction
Recurrent patellar dislocation is often reported in bilateral knees in young active individuals. The medial patellofemoral ligament (MPFL) tear is the attributable cause behind many of them and warrants reconstruction of the ligament to stabilize the patellofemoral joint. This study aimed to compare the clinical and functional outcomes following simultaneous bilateral MPFL reconstruction (MPFL-R) procedures with the staged bilateral MPFL-R procedures (one knee at a time). Methods- It was a retrospective matched cohort study. Out of a total of 58 patients of bilateral MPFL reconstruction, 22 patients had simultaneous bilateral MPFL reconstruction. From the remaining 36 patients of staged bilateral MPFL reconstruction, 22 were matched one-on-one to the simultaneous group of patients. Preoperative and the final postoperative Lysholm, Kujala, Tegner scores, and the range of knee movements of both groups were compared and analysed. The rate of complications and return to the theatre were noted in both groups. Results- With a mean follow-up of 7.7 years (1.8 years to 12.3 years), there was a significant improvement in clinical parameters observed in both the groups (p<0.05). No significant difference could be found between the two groups in terms of the Lysholm, Kujala, and the range of knee movements (p> 0.05). The rate of complication was comparable in both the groups (p>0.05). Conclusion- Simultaneous bilateral MPFL reconstruction surgery for bilateral patellofemoral joint instabilities leads to a clinical outcome that is not significantly different from that of the staged bilateral operative procedures done for the same. Also, there is no significant difference in the risk of complications following these two approaches.
Knee
Instability
Patellofemoral
Repair/Reconstruction
Acute Patella Dislocation
Dislocation
Female Athletes
Ligaments
MRI
Patellofemoral Ligament Rupture
Patellofemoral Osteoarthritis
Physical Examination
Recurrent Subluxation and Dislocation
X-ray

### 19608 Randomised prospective comparative analysis of functional outcome of osteosynthesis of intrarticular distal humerus fracture using triceps reflecting and transolecrenon approach

UK
Summary
Randomised prospective comparative analysis of functional outcome of osteosynthesis of intrarticular distal humerus fracture using triceps reflecting and transolecrenon approach
Data
Introduction
Intraarticular fractures of the distal humerus is one of the demanding injuries to manage due to its complex anatomy. Open reduction internal fixation is able to achieve painless, stable, and mobile joint. This study is aimed at comparing the functional outcomes of patients treated with triceps reflecting and olecranon osteotomy approach. Materials and methods: A hospital-based randomized comparative study of 40 patients diagnosed with distal humerus intraarticular fracture admitted to our hospital from April 2017 to March 2019. Triceps reflecting approach (group A) was used in 20 patients and olecranon osteotomy approach (group B) in 20 patients. Elbow range of movements and MEPS was used to compare the outcome.
Results
The mean elbow range of motion is 95.8 ± 13.5 degrees at 1 year follow up in Group A and 94.5 ± 9.3 degrees in 1 year follow up at 1 year follow up in Group B. The mean MEP score at end of 1 year in group A was 93.8 ± 2.9 and in the group, B was 91.5 ± 3.2 shows excellent results but there was no statistically significant difference between the MEP scores of the two groups. We observed 6 patients who developed extension lag less than 10 degrees in group A which was clinically insignificant and 7 patients developed hardware prominence in group B.
Conclusion
Triceps reflecting Bryan Morrey approach is equally effective as the olecranon osteotomy approach in the treatment of distal humerus intraarticular fracture with less complication and operative time.
Elbow/Wrist/Hand
Implant
Joints
Trauma
Outcome Studies
Rehabilition/Physical Therapy
X-ray

### 19453 Nerve injury during anterior cruciate ligament reconstruction: a comparison between patellar and hamstring tendon grafts harvest

Jonathan Singer
Ehud Rath
Mustafa Yassin
Shlomo Bronak
Barak Haviv
Israel
Summary
Harvesting tendon autografts for anterior cruciate ligament reconstructions by vertical incisions had high prevalence of saphenous nerve branches injury with a minor possibility for complete recovery within the first year.
Data
Background
Tendon harvesting for anterior cruciate ligament reconstruction often injures sensory branches of the saphenous nerve. The reports on the prevalence of these injuries are scarce, while the implications on patient satisfaction are not known. Our objective was to compare the prevalence of sensory nerve injuries in patellar to hamstring autograft harvesting for anterior cruciate ligament reconstructions and follow up their postoperative course.
Methods
Between 2012 and 2014, patients who had a primary anterior cruciate ligament re- construction with bone patellar tendon bone or hamstring autografts were included (n = 94). We evaluated and compared demographic details, level of activity and postoperative sensation disturbances between both groups. Data was analyzed retrospectively.
Results
The mean postoperative follow-up time was 23 months. At the last follow-up 46 (77%) patients of the patellar tendon group and 22 (58%) of the hamstring tendons group reported on reduced sensation; however, in both groups a quarter of these patients experienced full recovery within an average of seven to eight months. There were more patients in the hamstring tendons group that reported on partial recovery. In most cases midline incisions for patellar tendons harvesting injured the infrapatellar branch and medial incisions for hamstring tendons harvesting injured the sartorial branch of the saphenous nerve.
Conclusions
Harvesting tendon autografts for anterior cruciate ligament reconstructions by vertical incisions had high prevalence of saphenous nerve branches injury with a minor possibility for complete recovery within the first year. The loss of sensation was perceived by patients as a minor complication.
Knee
ACL
Autograft
Ligaments
Tears
Arthroscopy
Endoscopy
Evidence Based Medicine
Hamstrings Tendon Injury
Nerve
Patella Tendon Injury
Physical Examination
Rehabilition/Physical Therapy
Saphenous Nerve
Sport Specific Injuries
Sport Specific Population
Tendon

### 19591 Creating a crosswalk for knee outcomes after ACLR from the KOOS(5) to the IKDC-SKF

Jessica L Johnson1
Aaron Boulton1
Kurt P Spindler1
Laura J Huston1
Tim Spalding2
Laura Asplin2
May Arna Risberg2
Lynn Snyder-Mackler1
1USA
2UK
3Norway
Summary
We created a statistical method to convert KOOS scores to IKDC-SKF scores pre- and post-ACLR using three large datasets to enable more rigorous comparisons and pooling for meta-analysis.
Data
The variance of patient reported outcomes measures (PROM) used in both clinical and research practice limits the comparison of outcomes and prevents pooling of data for meta-analysis. Two commonly used PROM in anterior cruciate ligament (ACL) registries and cohorts are the Knee Injury Osteoarthritis Outcomes Survey (KOOS) and International Knee Documentation Committee-Subjective Knee Form (IKDC-SKF), but few studies collect or report both scores. Our objective was to create a statistical method to convert averaged KOOS scores to IKDC-SKF scores to enable more rigorous comparisons and pooling for meta-analysis.
Methods
We used equipercentile equating methods to create a statistical crosswalk in one ACL cohort at three time-points: pre-ACL reconstruction (ACLR) and 24- and 72-months after ACLR; this was validated in two other ACL cohorts at similar time-points: pre-ACLR and 24- and 60-months post-ACLR.
Results
We observed high correlations (r=0.81–0.90), unidimensionality (first to second eigenvalues= 8.7–13.3), and subpopulation invariance (root expected mean squared difference=0.009–0.017). The smallest disagreements between crosswalked and true scores was using the 24-month scores; these had a bias of less than 0.1 standard deviation unit.
Conclusion
Our crosswalk is statistically merited and accurately converts group level average KOOS scores to IKDC-SKF scores. This tool will allow for more comparisons and meta-analyses of outcomes after ACL reconstruction, improving our treatment of and outcomes after ACL injury and reconstruction.
Knee
ACL
Ligaments
Outcome Studies
Rehabilition/Physical Therapy

### 19517 Ligamentous laxity, male sex, chronicity, meniscus injury and posterior tibial slope are associated with a high-grade pre-operative pivot shift: a post hoc analysis of the stability study

Lachlan Batty1
Peter B MacDonald2
Tim Spalding3
Alan Getgood2
Andrew Firth2
Gilbert Moatshe4
Dianne M Bryant2
Mark A Heard2
Robert G McCormack2
Alex Rezansoff2
Devin Clarke Peterson2
Davide Bardana2
1Australia
3UK
4Norway
Summary
Ligamentous Laxity, Male Sex, Chronicity, Meniscus Injury and Posterior Tibial Slope are Associated with a High-Grade Pre-Operative Pivot Shift
Data
Introduction
A spectrum of anterolateral rotatory laxity exists in anterior cruciate ligament (ACL) injured knees. Understanding of the factors contributing to a high-grade pivot shift continues to be refined. The effect of a high-grade pivot shift on baseline patient reported outcome measures (PROMs) is unclear.
Purpose
To investigate factors associated with a high-grade pre-operative pivot shift and to evaluate the relationship between a high-grade pivot shift and baseline PROMs.
Methods
A post hoc analysis of 618 ACL deficient patients deemed high risk for re-injury enrolled in a randomised trial was performed. A binary logistic regression model was developed with a high-grade pivot shift (International Knee Documentation Committee [IKDC] Grade 3) as the dependent variable. Age, sex, Beighton score, chronicity, posterior third medial or lateral meniscus injury and tibial slope were selected as independent variables. The importance of knee hyperextension as a component of the Beighton score was assessed using receiver operator characteristic curves. Baseline PROMs were compared between patients with and without a high-grade pivot.
Results
Six factors were associated with a high-grade pivot shift. These were Beighton score (each additional point, OR 1.17, 95%CI 1.06–1.30, p=0.002), male sex (OR 2.30, 95%CI 1.28–4.13, p=0.005), the presence of a posterior third medial (OR 2.55, 95%CI 1.11–5.84, p=0.03) or lateral meniscal injury (OR 1.76, 95%CI 1.01–3.08, p=0.05), tibial slope >9° (OR 2.35, 95%CI 1.09–5.07, p=0.03) and chronicity >6 months (OR 1.70, 95%CI 1.00–2.88, p=0.05). The presence of knee hyperextension improved the diagnostic utility of Beighton score as a predictor of a high-grade pivot shift. There was an interaction between tibial slope and posterior third medial meniscus pathology; tibial slope <9 degrees was only associated with a high-grade pivot in the presence of posterior third medial meniscus injury. Patients with a high-grade pivot shift had higher baseline 4-Item Pain Intensity Measure (P4) pain scores (11 ?13 vs. 8 ?14, p=0.04); however, there was no difference between baseline IKDC, ACL-Quality of life (ACL-QOL), Knee Injury and Osteoarthritis Outcome Score (KOOS) or KOOS sub-scales.
Conclusion
Ligamentous laxity, male sex, posterior third medial or lateral meniscal injury, increased posterior tibial slope and chronicity are associated with a high-grade pivot shift in this population deemed high risk for repeat ACL injury. Knee hyperextension improves the prognostic utility of the Beighton score. The effect of tibial slope may be accentuated by the presence of meniscal injury, supporting the need for meniscal preservation. Baseline PROMs are similar between patients with and without a high-grade pivot shift.
Knee
ACL
Instability
Ligaments
Repair/Reconstruction

### 19381 Treatment modalities and outcomes following acetabular fractures in the elderly: a systematic review

Brian McCormick
Joseph Serino
Sebastian Orman
Alex R Webb
David X Wang
Sharri Mortenson
Arvind Von Keudell
USA
Summary
Elderly patients with acetabular fractures suffer from high rates of mortality and complications, and when determining surgical treatment in this population, THA alone or concurrent with ORIF should be considered given the significantly lower rate of non-fatal complications and similar mortality rate.
Data
Introduction
The treatment of geriatric acetabular fractures remains controversial. Treatment options include nonoperative management, open reduction and internal fixation (ORIF), total hip arthroplasty (THA) with or without internal fixation, and closed reduction with percutaneous pinning (CRPP). Determining the optimal management for a specific patient depends on several factors, including fracture pattern, concomitant injuries, and medical comorbidities. In young patients, ORIF often leads to favorable functional outcomes if anatomic reduction of the joint is achieved. Poor reduction quality and advanced age are associated with higher rates of failure and conversion to THA following ORIF. While arthroplasty is established as a treatment option for acetabular fractures and offers the benefit of early weight-bearing and mobilization, it is associated with high rates of deep infection and dislocation. The unique risks and complexities associated with acetabular fractures in the elderly make these injuries especially challenging for the orthopedic traumatologist. The purpose of this study is to compare adverse event rates, functional and radiographic outcomes, and intraoperative results between the various treatment modalities in order to help guide surgical decision making.
Study Design and Methods
We performed a systematic review to identify studies including patients aged = 55 with acetabular fractures. In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched PubMed, MEDLINE, Embase, and Web of Science electronic databases using a combination of controlled vocabulary and keywords (acetabulum or acetabular and fracture, fractures, or fractured) limited to the title or abstract fields.
Results
Thirty-eight studies including 3,928 patients with a mean age of 72.6 years and a mean follow up duration of 29.4 months met our eligibility criteria. The mean Harris Hip Score (HHS) for all patients was 81.9 and was highest in the nonoperative group (mean HHS=93.2). The pooled mortality rate of all patients was 21.6% (95% confidence interval [CI]=20.9–22.4%) with a mean time to mortality of 21.6 months, and the pooled non-fatal complication rate was 24.7% (95% CI=23.9–25.5%). Patients treated with ORIF had a significantly higher non-fatal complication rate than those treated with ORIF+THA, THA alone, CRPP, or nonoperative management (odds ratios [ORs]=1.87, 2.24, 2.15, and 4.48, respectively; p<0.01). Patients that underwent ORIF were significantly less likely to undergo subsequent THA than those treated with CRPP (OR=0.49, p=0.002) but were more likely to require THA than patients treated nonoperatively (OR=6.81, p<0.001).
Conclusion
Elderly patients with acetabular fractures suffer from high rates of mortality and complications. There was a high rate of conversion to THA in patients treated with internal or percutaneous fixation. When determining surgical treatment in this population, THA alone or concurrent with ORIF should be considered given the significantly lower rate of non-fatal complications and similar mortality rate. Nonoperative management remains a viable option and was associated with the lowest non-fatal complication rate.
Hip/Groin/Thigh
Arthroplasty
Bones
Trauma
Acetabular Fracture
CT-Scan
Dislocation
Elderly
Infection
Osteoporosis
Outcome Studies
X-ray

### 19771 Typical pain patterns in patients after total knee arthroplasty

Dominic Thierry Mathis
Samuel Tschudi
Antonia Hauser
Amsler Felix
Helmut Rasch
Michael T Hirschmann
Switzerland
Summary
The results of this study involving specific pain patterns in unhappy TKA patients, help to further differentiate and define the clinical picture of a painful TKA and place component positioning in the overall context of the ”painful knee arthroplasty”.
Data
Background
Total knee arthroplasty (TKA) is a highly effective treatment method of end-stage osteoarthritis and most patients experience pain relief within 3–6 months. However, about 20% of the patients are not satisfied nor pain free. The causes for recurrent pain after TKA are manifold and range from knee joint-related factors such as infection, arthrofibrosis, patellofemoral problems, malposition or malalignment, loosening or instability to non-knee joint-related causes such as psychological disorders, vascular pathologies, back or hip problems. Hence, the diagnostic process is demanding. The primary aim was to assess characteristics of pain in patients with ongoing pain after TKA and link the identified pain patterns to underlying pathologies. The secondary aim was to investigate the position of TKA components and evaluate bone tracer uptake (BTU) using pre-revision SPECT/CT and correlate these findings with the pain characteristics.
Methods
A prospectively collected cohort of 83 painful primary TKA patients was retrospectively evaluated. All patients followed a standardised diagnostic algorithm including 99m-Tc-HDP-SPECT/CT, which led to a diagnosis indicating revision surgery. Pain character, location, dynamics and radiation were systematically assessed as well as TKA component position in 3D-reconstructed CT. BTU was anatomically localised and quantified using a validated localization-scheme. Component positioning and BTU were correlated with pain characteristics using nonparametric Spearman correlations (p<0.05).
Results
Most frequent pain characters were pricking/lancinating (45.7%), pinching/crushing and dull/heavy (38.6%); 89.5% of all patients localized their knee pain anteriorly; 48.1% reported pain aggravations by descending stairs. Radiating pain was reported in 14% of the patients. Patella-related problems (56.7%) and instability (52.6%) were the most frequent pathologies. Significant correlations were found between pain and patients characteristics and SPECT/CT findings resulting in nine specific patterns. The most outstanding ones include: Pattern 1: More flexion in the femoral component correlated with tender/splitting pain and patella-related pathologies. Pattern 3: More varus in the femoral component correlated with dull/heavy and tingling/stinging pain during descending stairs, unloading and long-sitting in patients with high BMI and unresurfaced patella. Pattern 6: More posterior slope in the tibial component correlated with constant pain.
Conclusion
The results of this study involving specific pain patterns in unhappy TKA patients, help to place component positioning in the overall context of the ”painful knee arthroplasty”. Furthermore, the findings further differentiate and define the clinical picture of a painful knee after TKA. Knowing these patterns enables a prediction of the cause of the pain to be made as early as possible in the diagnostic process before the state of pain becomes chronic.
Knee
Arthroplasty
Cartilage
Osteoarthritis
CT-Scan
Elderly
X-ray

### 19620 Transtibial pullout and partial meniscectomy for medial posterior meniscal root tears in middle-aged patients: risk factors and midterm clinical outcomes. a case-control study

Lika Dzidzishvili
Irene Isabel López-Torres
Jm Arguello
David Sáez
Amaya Barberia
Emilio Calvo
Spain
Summary
Transtibial pullout repair of medial meniscus posterior root tears showed improved clinical outcomes in middle-aged patients with decreased progression of knee osteoarthritis compared with partial meniscectomy
Data
Background
There are limited data regarding the prognostic factors and clinical outcomes of medial meniscus posterior root tear in middle-aged patients with moderate knee osteoarthritis. Objectives This study aims at (1) comparing clinical and radiological outcomes, rate of conversion to knee arthroplasty in middle-aged patients undergoing transtibial pullout technique versus partial meniscectomy, (2) at establishing correlations between preoperative radiological findings as prognostic factors and postoperative clinical outcome. The hypothesis of this study was that the transtibial pullout technique would provide better functional outcomes overall, with lower conversion to knee arthroplasty compared to partial meniscectomy and one or more prognostic factors for poor clinical outcome could be identified among the study variables used.
Study Design and Methods
A comparative case-control analysis was conducted. 65 patients between 40 and 70 years of age were included into two groups: 30 patients who underwent transtibial pullout technique (group 1) and 35 patients who underwent partial meniscectomy (group 2). Mean follow-up was set at 27.2 months. Primary clinical outcomes included Knee injury and Osteoarthritis Outcome Score and Lysholm Knee Questionnare. Preoperative MRI and intraoperative arthroscopic findings were recorded. The correlation between these findings and patient-reported subjective outcome were assessed. Results The transtibial pullout group exhibited significantly greater improvement in clinical outcomes. A univariate model revealed that the presence of preoperative meniscal extrusion, body mass index (>30), osteochondral defect, and female gender were predictors of poor clinical outcome. Multivariate regression analysis showed meniscal extrusion and osteochondral defect as significant prognostic factors for both study groups.
Conclusions
Medial meniscus root repair leads to significantly improved clinical outcomes compared to partial meniscectomy and may be considered a valid option in middle-aged patients with moderate osteoarthritis. Presence of meniscal extrusion, osteochondral defect, BMI >30, and female gender were predictors of poor patient-reported outcome.
Knee
Meniscus
Repair/Reconstruction
Tears
Arthritis
Arthroscopy
Evidence Based Medicine
Medial
MRI
Osteoarthritis
Outcome Studies
Physical Examination
Posterior Pain
Sutures/Knots/Anchors
Trauma

### 19622 Outcomes of arthroscopic latarjet procedure for anterior glenohumeral instability in patients with epilepsy. A case-control study

Lika Dzidzishvili1
Claudio Calvo Palma2
María Valencia Mora1
Diana Morcillo Barrenechea1
Antonio Foruria1
Emilio Calvo1
Spain
Chile
Summary
Functional and subjective clinical outcomes of epileptic patients with anterior shoulder instability after arthroscopic Latarjet stabilization were comparable with those of non-epileptic patients
Data
Background
Outcomes following Latarjet for anterior shoulder instability in epileptic patients are still a matter of debate. Unacceptably high rates of re-dislocations after surgery, reoperation and coracoid nonunion were reported in patients with a seizure disorder after Latarjet repair. Objectives The main goal of this study was to evaluated functional and radiographic results, recurrence and coracoid nonunion rates of the arthroscopic Latarjet procedure for anterior shoulder instability in patients with epilepsy and comparing with the results of patients without epilepsy.
Study Design & Methods
A comparative case-control analysis was conducted including nineteen patients (twenty-one unstable shoulders) with a seizure disorder and who underwent arthroscopic Latarjet procedure (epileptic-group) by the same senior surgeon, were matched with twenty-one patients without a history of seizure (non-epileptic group) who also underwent arthroscopic Latarjet repair. Clinical outcomes at a minimum of 3 years (range, 3–9 years) postoperatively included Rowe score, Western Ontario Shoulder Instability Index, Constant-Murley Shoulder Outcome score and Single Assessment Numeric Evaluation. Demographics, surgical indications and imaging data were collected. The incidence of complications, recurrent instability, re-dislocation, revision surgery, repeat seizure(s) and presence of coracoid nonunion were also examined.
Results
After a mean follow-up of 5.8 years, no significant differences for functional results were found between epileptic and non-epileptic patients on the average ROWE; WOSI; Constant and SANE scores (P=0.500; 0.173; 0.193; 0.859; respectively). A total of five patients (seven shoulders) continued to have seizures post-operatively but no glenohumeral instability was documented. Osteo-arthritic changes of the glenohumeral joint were observed in five shoulders (26.3%) in the epileptic patient group and in three shoulder (15.0%) in the non-epileptic group (p=0.451). No case of coracoid nonunion or ostelysis were recorded in any of the two groups investigated There was no statistically significant difference in postoperative athletic activity (p=0.660). However, epileptic patient revelead significantly descreased postoperative sports participation (p=<0.001).
Conclusions
The functional and subjective clinical outcomes of epileptic patients with anterior shoulder instability after arthroscopic Latarjet stabilization were comparable with those of non-epileptic patients with no significant difference of coracoid nonunion and re-dislocation rate. However, decreased postoperative sports participation is expected in patient with a seizure disorder.
Shoulder
Arthroscopy
Glenohumeral
Instability
Arthrography
CT-Scan
Dislocation
Labrum
MRI
Outcome Studies
Repair/Reconstruction
Trauma
X-ray

### 19445 The role of joint line position and restoration of posterior condylar offset in revision total knee arthroplasty, a systematic review of 422 revision knees arthroplasty

Hany Elbardesy
Rehan Gul
James Harty
Ireland
Summary
Preservation of JL should be a major consideration when undertaking RTKA. Of note, increasing PFCO to balance the flexion gap while maintaining joint line should be well assessed intra-operatively.
Data
Abstract Objectives The aim of this systematic review was to evaluate the evidence on reservation of posterior Femoral condylar offset (PFCO) and Joint line (JL) with improved functional results after Revision Total Knee Arthroplasty (RTKA). Methods A comprehensive search of PubMed, Medline, Cochrane, CINAHL, and Embase databases was conducted since the inception of the database to October 2020. All relevant articles were retrieved, and their bibliographies were hand searched for further references on Posterior condylar offset and revision total knee arthroplasty. The search strategy yielded 28 articles. After duplicate removal titles, abstracts and full text were reviewed. Nine studies were assessed for eligibility, four studies were excluded because they did not fully comply with the inclusion criteria. Sex articles were finally included in this systematic review. Results Based on this systematic review restoration of the JL and PFCO in RTKR is associated with significant improvement in the post operative range of motion, KSS, OKS, patellar function, and SF-36. Conclusion Preservation of JL should be a major consideration when undertaking RTKA. Of note, increasing PFCO to balance the flexion gap while maintaining joint line should be well assessed intra-operatively.
Knee
Bones
Osteoarthritis
Total Joint Replacement
Biomechanics
Physical Examination
X-ray

### 19698 A high rate of children and adolescents return to sport after surgical treatment of osteochondritis dissecans of the elbow: a systematic review and meta-analysis

Dan Cohen
Jeffrey Kay
Muzammil Memon
Nicole Simunovic
Olufemi R Ayeni
Summary
This systematic review found that a high rate of children and adolescents return to sport at any level and at the competitive level after surgical management of osteochondritis dissecans of the elbow, with an overall return to any level of sport of 97.6% and a return to competitive sport of 86.9% with additional improvement in all postoperative functional outcome scores.
Data
Purpose
The purpose of this systematic review was to determine the return to sport rates following surgical management of ostechondritis dissecans of the elbow.
Methods
The databases EMBASE, PubMed, and MEDLINE were searched for relevant literature from database inception until August 2020 and studies were screened by two reviewers independently and in duplicate for studies reporting rates of return to sport following surgical management of posterior shoulder instability. A meta-analysis of proportions was used to combine the rates of return to sport using a random effects model. A risk of bias assessment was performed for all included studies using the MINORS score.
Results
Conclusion
Surgical management of osteochondritis dissecans of the elbow resulted in a high rate of return to sport, including in competitive and overhead athletes. Similar rates of return to sport were noted across both open and arthroscopic procedures.
Elbow/Wrist/Hand

### 19561 Does suture tape reinforcement lead to improved 2-year clinical outcomes for posterior cruciate ligament reconstruction?

Erik Therrien1
Ayoosh Pareek2
Bryant M Song2
Ryan R Wilbur2
Michael J Stuart2
Bruce A Levy2
2USA
Summary
All-inside single bundle PCL reconstruction with independent suture tape reinforcement was performed safely with a low rate of complications, graft failure, reoperation, and similar patient reported outcomes at minimum 2-year follow-up
Data
Objective: The objective of this study was to compare (1) rates of complications and reoperations, (2) posterior cruciate ligament (PCL) laxity and (3) patient-reported outcomes (PROs) among patients following all-inside single bundle posterior cruciate ligament reconstruction (PCLR) with and without independent suture tape reinforcement at minimum 2 year follow-up.
Methods
A retrospective cohort study from a prospectively gathered database was performed at a single academic institution from October 2012 to January 2019. Patients who underwent primary, all-inside allograft single-bundle PCLR with and without independent suture tape reinforcement and a minimum 2-year follow-up were identified. Medical records were reviewed for demographics, additional injuries, and concomitant procedures. Kneeling radiographs were collected at a minimum of 11 months postoperatively. PRO scores (including the International Knee Documentation Committee (IKDC), the Tegner activity and Lysholm scores), and physical exam findings were collected at a minimum of 2 years postoperatively.
Results
50 patients who underwent PCLR were identified: 19 patients (30.6 ± 12.7 years) with independent suture tape reinforcement and 31 patients (26.2 ± 9.0 years) without suture tape reinforcement. There was no difference between the groups regarding age, sex, BMI and KD grade. All included patients had a documented PCL injury on MRI with a grade 2+ or higher posterior drawer examination preoperatively. Postoperative range of motion was similar between the two groups: −0.6 ± 1.6° to 128.3 ± 9.4 ° in the suture tape reinforcement group vs 0.2 ± 1.6 ° to 124.5 ± 13.6 ° in the control group (p=.591). At 2 years postoperatively, posterior drawer examination showed grade 1+ laxity in 4/19 (21%) of the suture tape cohort vs 6/31 (19%) of the control cohort. No grade 2 or grade 3 laxity was noted in either group. Kneeling radiographs showed no side-to-side difference between the two groups: 1.9 ± 1.8 mm in suture tape reinforcement group vs 2.6 ± 2.2 mm in control group (p=.360). There were no statistically significant differences between the suture tape and control groups in postoperative IKDC scores (79.3 and 79.6, respectively), Lysholm scores (87.5 and 84.3, respectively) and Tegner activity scores (5.6 and 5.7, respectively). One PCLR graft failure was documented in the suture tape group, and none in the control group. Overall, 5/19 (26%) suture tape patients and 3/31 (10%) control patients underwent reoperation (p=.232), including 2 superficial wound debridements, 2 multi-ligament reconstructions due to traumatic injuries, and 1 meniscal surgery in the suture tape group. There were 2 lysis of adhesions and 1 superficial wound debridement in the control group.
Conclusions
All-inside single bundle PCL reconstruction with independent suture tape reinforcement was performed safely with a low rate of complications, graft failure, and reoperation at minimum 2-year follow-up. All-inside posterior cruciate ligament reconstruction with and without independent suture tape reinforcement resulted in similar patient reported outcomes and postoperative laxity at 2-year follow-up.
Orthopaedic Sports Medicine
Arthroscopy
Knee
Ligaments
Meniscus
PCL

### 19388 Beach chair versus lateral decubitus positioning for primary arthroscopic anterior shoulder stabilization: a consecutive series of 641 shoulders

Bobby Yow
Matthew Posner
Jon FDickens
Ashley Bee Anderson
Zein Aburish
David J Tennent
Lance LeClere
John-Paul Rue
Brett D Owens
Michael A Donohue
Kenneth L Cameron
USA
Summary
Equivalent outcomes may be anticipated with arthroscopic Bankart repair performed in the BC or LD position.
Data
Introduction
There are no studies that directly compare beach chair (BC) versus lateral decubitus (LD) position for anterior instability. In the only systematic review evaluating BC vs. LD, bone loss is not accounted for in the recurrence rate. The purpose of this is to identify predictors of shoulder instability recurrence and revision after anterior shoulder stabilization surgery in a young, high demand population and evaluate surgical position and glenoid bone loss as independent predictors of the outcomes of interest, recurrence and revision at short- and mid- term follow-up.
Methods
A consecutive series of 641 arthroscopic Bankart stabilizations were performed by sports medicine certified and fellowship trained orthopaedic surgeons from 2005–2019 in either the BC or LD position. Patients were included if they underwent an isolated primary arthroscopic anterior capsulolabral repair. Patients were excluded if concomitant labral repair and/or Remplissage procedures were performed at the time of surgery. Shoulders were additionally excluded if magnetic resonance imaging (MRI) was not available at the time of preoperative evaluation or the patient was lost to follow up. All shoulders were evaluated for glenohumeral bone loss using the perfect circle technique on the sagittal en-face MRI as well as for bipolar lesions according to the on/off-track method of Diagacomo et al. Glenoid bone loss was grouped into three categories: <5%, 5–13.5%, and >13.5%. The primary outcomes of interest were recurrent instability and revision stabilization. Recurrent instability was defined as the presence of a recurrent subluxation and or dislocation event and/or the presence of a positive apprehension. Multivariable logistic regression models were used to assess the relationships of outcomes with age, position, glenoid bone loss group, and track.
Results
A total of 641 shoulders with a mean age of 22.3 years (SD 4.45) underwent isolated arthroscopic Bankart repair and were followed for a mean 6 years. The overall one-year recurrent instability and revisions rates were 3.3% (21/641) and 2.8% (18/641), respectively. At one-year, recurrent instability was observed in 2.3% (11/487) and 6.5% (10/154) of BC and LD shoulders. The five-year recurrent instability and revision rates were 15.7% (60/383) and 12.8% (49/383). At five-years, recurrent instability was observed in 16.4% (48/293) and 13.3% (12/90) of BC and LD shoulders. When adjusted for age, position, and bone loss group, multivariable logistic regression modeling demonstrated surgical position was not associated with risk of recurrent instability after one-year (OR for LD vs BC = 1.39; p=0.56) and five-year (OR for LD vs BC=1.32, p=0.43) follow-up time periods. However, after five-year follow-up younger age at index surgery was independently associated with higher risk of recurrent instability: OR = 1.73 per SD (4.1 years) decrease in age (P<0.03) After one-year and five-year follow-up time periods, surgical position results were similar in a separate multivariable logistic regression model of revision surgery as the dependent variable, when adjusted for age, branch, bone loss group, and track. After five year follow-up, only younger age at time of index surgery remained an independent risk factor for revision: OR 1.68 per SD (4.1 years) decrease in age (P<0.05).
Conclusions
Among fellowship-trained orthopaedic surgeons, there was no difference in rates of recurrent instability and revision surgery after performing arthroscopic stabilization for isolated anterior shoulder instability in a high demand population in either the BC or LD position. In multivariable analysis, younger age, but not surgical position, was an independent risk factor for recurrence.
Shoulder
Arthroscopy
Glenohumeral
Instability
Bones
Capsuloligamentous Complex
Dislocation
Glenoid Fracture
Labrum
Sport Specific Population

### 19390 Progression to glenohumeral arthritis after arthroscopic anterior stabilization in a young and high demand population

Bobby Yow
Ashley Bee Anderson
Sean E Slaven
Kelly Kilcoyne
Jon F Dickens
USA
Summary
The progression to glenohumeral arthritis after anterior stabilization surgery occurred in 8% of a young and high demand patient population.
Data
Introduction
Shoulder instability is a common cause of shoulder pain and dysfunction, particularly in young and active individuals. While arthroscopic stabilization for anterior glenohumeral instability has shown excellent success preventing recurrent instability and allowing return to sport, eventual progression to glenohumeral arthritis remains a concern in these patients. Older age, higher number of anchors used, and greater capsular shrinkage have been previously established as risk factors for progression to glenohumeral arthritis in patients who underwent arthroscopic anterior stabilization. However, the rate of and risk factors for arthritis post-surgery in young and high demand populations have not been well characterized and may be important in guiding decision making when treating the young patient with first time shoulder instability. The purpose of this study was to evaluate the rate of progression to glenohumeral arthritis and identify potential risk factors after arthroscopic anterior stabilization in a young and high demand population.
Methods
This study included 287 active duty servicemembers identified in the Military Heath System (MHS) with anterior shoulder instability who underwent primary arthroscopic surgical stabilization and had postoperative imaging or medical records available over a 12-year period between January 2004 and September 2016. All procedures were performed at a single institution. Patients were excluded if they had previously undergone a stabilization procedure on the shoulder of interest, if no preoperative imaging was available, if they did not have a minimum follow up of four years, or if operative information regarding the number of anchors used was unavailable. Presence of arthritis (yes/no) was defined over follow up using radiographic parameters as described by Samielson and Prieto identifying patients with at least mild arthritis. Kaplan-Meier survival curves were estimated for development of arthritis and compared by patient characteristics using log-rank tests. Cox proportional hazard models were used to calculate Hazard Ratios (HR) with 95% confidence intervals (95% CI) associated with patient characteristics as predictors of the development of glenohumeral arthritis, adjusted for confounders identified in univariate analyses.
Results
Among the 287 patients with anterior shoulder instability requiring surgical fixation, 8% (23/287) developed glenohumeral arthritis. The mean age of all patients was 22.7 years (SD 5.26). The median time to diagnosis of arthritis was 8 years and the median follow-up time was 9 years (IQR 6;11). Kaplan-Meier curves showed differences in time to arthritis among patient groups stratified by age, index surgery anchor number, and revision (yes/no), (log rank p for each <0.05). Adjusted for potential confounders in a multivariable Cox regression model, risk factors for the development of glenohumeral arthritis included age (HR=1.85, 95% CI, 1.34 to 2.55), index surgery anchor number (HR=1.54, 95% CI, 1.11 to 2.14), and revision before diagnosis with glenohumeral arthritis (HR=2.83, 95% CI=1.15 to 6.95).
Conclusion
This is the largest series looking at glenohumeral arthritis after arthroscopic surgical stabilization for anterior shoulder instability. The progression to glenohumeral arthritis after anterior stabilization surgery occurred in 8% of a young and high demand patient population. Patient age and number of anchors used are statistically significant risk factors for progression to arthritis. Additionally, revision surgery was found to be a risk factor, which has not been previously reported in the literature. These results demonstrate decreased rates of arthritis when compared to older populations, which may advocate for early surgical intervention for a young patient presenting with shoulder instability.
Shoulder
Arthritis
Arthroscopy
Glenohumeral
Capsuloligamentous Complex
Cartilage
Labrum
Osteoarthritis
Sport Specific Population

### 19389 Progression to glenohumeral arthritis after arthroscopic posterior stabilization in a young and high demand population

Bobby Yow
Ashley Bee Anderson
Patrick Mescher
Timothy Murphy
Sean E Slaven
Jon F Dickens
USA
Summary
The rate of progression to glenohumeral arthritis after arthroscopic posterior stabilization surgery was 12% in a young and high demand population.
Data
Introduction
Shoulder instability is a common cause of shoulder pain and dysfunction, particularly in young and active individuals. While anterior instability remains the most common type, recent literature shows that posterior instability occurs more frequently than previously thought. As opposed to its anterior counterpart, posterior instability most often presents with pain, particularly in active individuals involved in dynamic posterior loading of the shoulder resulting in repetitive microtrauma of the posterior capsulolabral structures. While arthroscopic stabilization for posterior glenohumeral instability has shown excellent success preventing recurrent instability and allowing return to sport, eventual progression to glenohumeral arthritis remains a concern in these patients. However, the rate of and risk factors for arthritis post-surgery in young and high demand populations have not been described in the literature and may be important in guiding decision making when treating the young patient with posterior shoulder instability. The purpose of this study was to evaluate the rate of progression to glenohumeral arthritis and identify potential risk factors after arthroscopic posterior stabilization in a young and high demand population.
Methods
This study included 110 active duty servicemembers identified in the Military Heath System (MHS) with posterior shoulder instability who underwent primary arthroscopic surgical stabilization and had postoperative imaging or medical records available over a twelve-year period between January 2004 and September 2016. All procedures were performed at a single institution. Patients were excluded if they had previously undergone a stabilization procedure on the shoulder of interest, if no pre-operative imaging was available, or if operative information regarding the number of anchors used was unavailable. Presence of arthritis (yes/no) was defined over follow-up using radiographic parameters as described by Samilson and Prieto identifying patients with at least ‘mild arthritis.” Glenohumeral bone loss was reported as a continuous variable using the perfect circle technique. Kaplan-Meier survival curves were estimated for development of arthritis and compared by patient characteristics using log-rank tests. Cox proportional hazard models were used to calculate Hazard Ratios (HR) with 95% confidence intervals (95% CI) associated with patient characteristics as predictors of the development of glenohumeral (GH) arthritis. The proportional hazards assumption was evaluated for each predictor using Schoenfeld residual-based tests.
Results
Among the 110 patients with posterior shoulder instability requiring surgical fixation, 12.7% (14/110) developed glenohumeral arthritis. The mean age of all patients was 23.9 years (SD 6.7). The Kaplan-Meier estimate of 10-year survival free of GH arthritis was 0.87 (0.79, 0.95). The median follow-up time was 8.1 years (IQR 5.8). Kaplan-Meier curves did not show statistical differences in time to arthritis among patient groups stratified by age (HR (per 10 year increase) 1.45 (95% CI 0.76, 2.74), index surgery anchor number (HR 1.21 (95% CI 0.75, 1.93), or glenoid bone loss (HR 0.87 (95% CI 0.74, 1.03).
Conclusion
No previous study has reported the incidence and risk factors for glenohumeral arthritis after arthroscopic surgical stabilization for posterior shoulder instability. The progression to glenohumeral arthritis after posterior stabilization surgery occurred in 12.7% of a young and high demand patient population over median follow-up of 8.1 years. No patient characteristics were found statistically associated with risk of GH arthritis; however statistical power was limited by the low incidence of GH arthritis in our cohort. The near significant confidence interval for glenoid bone loss and the potentially clinically relevant effect size for higher risk with increasing age warrant further evaluation in larger cohorts which may help guide clinical decision making and chronicity of treatment.
Shoulder
Arthritis
Arthroscopy
Glenohumeral
Capsuloligamentous Complex
Cartilage
Labrum
Osteoarthritis
Sport Specific Population

### 19392 Increasing injury risk among recent generation of u.s.-raised players in the national basketball association: a 15-year perspective

Kelvin Kim
Robbie Birch
Brett Allen
Jason Nielson
USA
Summary
The purpose of this study is to determine the epidemiology and trends of specific overuse injuries in U.S.-raised NBA players over the past 15 years.
Data
Purpose
There is growing concern of increasing injury rates among the recent generation of players in the National Basketball Association (NBA). Although these concerns are limited to anecdotal evidence, the current thought focuses on recent trends in youth player development including early single-sport specialization, increasingly rigorous training regimens, and the high volume of games played annually. In an effort to protect and promote safe player-development practices among youth basketball players, and ultimately those who continue on to the collegiate and professional levels, the purpose of this study is to determine the epidemiology and trends of specific overuse injuries in U.S.-raised NBA players over the past 15 years. Additionally, a comparative injury analysis was performed between U.S. and foreign-raised players. Our hypothesis is that, over the past 15 seasons, there has been (1) an increased risk of overuse injuries among more recently drafted U.S.-raised players, (2) a higher risk of overuse injuries among U.S.-raised players than foreign-raised players.
Methods
All overuse injuries sustained during players’ first 2 seasons were retrospectively analyzed between 2003–2019. Players were separated into cohorts based on whether they had spent the majority of their amateur careers playing in the U.S. (US) versus outside of the U.S. (OUS). Regression analysis was performed to analyze injury risk within the US cohort as well as between the US and OUS cohorts.
Results
Five-hundred forty-nine (80.9%) and 129 players (19.0%) were identified in the US and OUS cohorts, respectively. A significantly higher risk of ankle sprains (OR 1.18, p=0.047, CI [95%] 1.002–1.389), back strains (OR 1.79, p=0.010, CI [95%] 1.153–2.791), hip strains (OR 4.12, p<0.001, CI [95%] 1.937–8.775), toe sprains (OR 1.86, p<0.001, CI [95%] 1.024–3.380) and total injuries (OR 1.23, p<0.001, CI [95%] 1.061–1.446) was observed among more recently drafted US players. The OUS cohort did not show increased injury risk by body location or total injuries among recent draftees. When comparing injury risk between the US and OUS cohorts, the US cohort showed a significantly higher risk of knee sprains (OR 8.26, p=0.038, CI [95%] 0.610–1.330), foot sprains (OR 9.34, p=0.031, CI [95%] 1.221–71.421), and total injuries (OR 4.25, p=<0.001, CI [95%] 2.374–7.600).
Conclusion
Our findings reflect the growing concern of increasing injury risk among the newer generation of U.S.-raised NBA players. Insight into increasing injury rates may be found in the training methods used to develop foreign-raised players, who appear to be less injury-prone based on our study. This is the first published study to our knowledge analyzing overuse injury trends during the early stages of NBA players’ careers. In an effort to mitigate injury risk among competitive youth basketball players, incorporating injury prevention measures into routine training regimens as well as adherence to safe training guidelines is recommended.
Knee
Bones
Cartilage
Epidemiology
Ligaments
Meniscus
Preventative Sports Medicine
Protective Equipment
Sport Specific Injuries
Team Physician
Tears

### 19696 Hip osteochondroplasty may benefit the non-ideal patient with femoroacetabular impingement: analysis from the embedded prospective cohort of the first trial

Mahmoud Almasri1
Nicole Simunovic2
Diane Heels-Ansdell2
Olufemi R Ayeni2
1USA
Summary
The benefits of the osteochondroplasty procedure shown in the FIRST trial, appear to also apply to patients commonly seen in regular practice.
Data
Background
Randomized controlled trials (RCTs) typically have specific eligibility criteria that lead to the recruitment of optimized or ideal patient populations for the interventions under study. The Femoroacetabular Impingement RandomiSed controlled Trial (FIRST) demonstrated the efficacy of arthroscopic osteochondroplasty when compared to arthroscopic lavage in the treatment of femoroacetabular impingement (FAI) in ideal patients at 2 years. During the FIRST trial, we concurrently ran an embedded prospective cohort study that enrolled patients who either did not meet the full trial eligibility criteria or who refused to participate in the RCT and therefore were treated with arthroscopic osteochondroplasty as per standard of care. We present the results of this embedded cohort study to determine if arthroscopic osteochondroplasty demonstrated effectiveness (i.e., the intervention was also beneficial to a non-ideal, pragmatic FAI patient population).
Methods
All cohort patients were not randomized and were followed prospectively with a follow-up assessment protocol identical to that in the FIRST trial. The primary outcome was hip pain using a 100-point Visual Analogue Scale (VAS). Secondary outcomes included hip function (Hip Outcome Score, HOS; International Hip Outcome Tool, iHOT-12), health utility (EQ-5D), and health-related quality of life (SF-12 mental and physical component summary scores, MCS and PCS) at 12 months as well as operatively and non-operatively treated hip complications at 24 months. We performed multiple linear regressions to compare these outcomes between 3 groups of patients: (1) those randomized to lavage in the FIRST trial, (2) those randomized to osteochondroplasty in the FIRST trial, and (3) those who received osteochondroplasty as part of the cohort study. Regression model covariates included: impingement sub-type, age, sex, severity of baseline impingement, presence of comorbidities at baseline, temporary pain relief from diagnostic hip injection prior to surgery, body mass index (BMI), and baseline score for all questionnaire outcomes.
Results
Similar to the results of the FIRST trial, all groups had improvements in VAS pain scores from baseline to 12 months, and experienced similar improvements in hip function (HOS, iHOT-12), health utility (EQ-5D), and health-related quality of life (SF-12 MCS and PCS), with no significant differences between groups. From the logistic regression model adjusting for age, there were significantly more re-operations in the lavage trial group compared to those in the embedded cohort (i.e. ‘non-ideal’ patients who received osteochondroplasty) (adjusted odds ratio, OR 3.08; 95% confidence interval, CI 1.23 to 7.73; p = 0.016). There were significantly more non-operatively treated complications in the lavage trial group and in the osteochondroplasty trial group when compared to those in the embedded cohort (adjusted OR 3.81; 95% CI 1.19 to 12.17; p = 0.024 and adjusted OR 4.55; 95% CI 1.43 to 14.42; p = 0.010, respectively). These results were consistent across the adjusted and unadjusted analyses.
Conclusion
Hip arthroscopic osteochondroplasty leads to improvement in hip pain, function, and health-related quality of life at 12 months across both RCT (ideal) and cohort (non-ideal) patients. Those receiving osteochondroplasty as part of the pragmatic cohort had significantly fewer re-operations and other complications when compared to RCT patients randomized to either arthroscopic lavage or osteochondroplasty. The benefits of the osteochondroplasty procedure shown in the FIRST trial, appear to also apply to patients commonly seen in regular practice.
Hip/Groin/Thigh
Arthroscopy
Impingement
Bones
Epidemiology
Labrum
Labrum Treatment

### 19542 Does medialization of glenoid bone-baseplate interface caused by eccentric reaming influence outcomes of reverse shoulder arthroplasty?

Prashant Meshram
Jorge Rojas Llevano
Stephen C Weber
Uma Srikumaran
Edward G McFarland
USA
Summary
In primary RSA using a lateralized implant, medialization of glenoid bone-baseplate interface after eccentric reaming does not influence shoulder range of motion, patient-reported outcome scores, postoperative pain scores, baseplate loosening, or glenoid notching.
Data
Background
One of the major concerns with reverse shoulder arthroplasty (RSA) is dealing with the glenoid bone loss that is severe enough to compromise baseplate stability. The influence of increasing the medialization of the bone-baseplate interface (MBBI) resulting from reaming the glenoid while using a lateralized glenosphere RSA system has not been studied before. This study aims were to determine (1) What is the influence of different magnitudes of MBBI on clinical outcomes including range of motion (ROM) and patient reported outcomes (PROs)? and (2) What is the influence of increasing MBBI on the incidence of baseplate failure and scapula notching?
Methods
We retrospectively reviewed 91 patients who underwent primary RSA after a minimum 2-year follow-up. The amount of MBBI was estimated using a 3-dimensional CT scan-based computer planning software. Patients were categorized into three groups depending on whether MBBI was less than 3 mm (Group low MBBI, N = 32), between 3 mm to 5 mm (Group moderate MBBI, N = 30), or more than 5 mm (Group high MBBI, N = 29). Range of motion (ROM), American Shoulder and Elbow Surgeons (ASES) score, Simple Shoulder Test (SST) score, and scapular notching were compared between groups.
Results
Mean MBBI was 1.5 mm (range, 0.5 - 2.5 mm) in low MBBI group, 3.5 mm (range, 3.0 - 5.0 mm) in moderate MBBI group, and 7 mm (range, 5.5–1.0 mm) in high MBBI group. At the last follow-up, there was no statistical difference (all P > 0.05) in clinical results when compared between low, medium, and high MBBI groups for mean ASES (74 vs 67 vs 75), SST (8 vs 7 vs 9), VAS for pain (1.3 vs 2.3 vs 2,7), abduction (121° vs 120° vs 123°), external rotation at 90° abduction (60° vs 60° vs 55°), and internal rotation at back (lumbosacral vs lumbosacral vs waist). There was no correlation between the amount of MBBI and improvement in ROM in any plane. There was no baseplate loosening in any patient. There was no statistical difference (P > 0.05) in scapula notching at the final follow up in low (17%), moderate (33%), and high (24%) MBBI groups. There was no significant correlation between the amount of MBPI and postoperative change in abduction (rs = −0.12, p = 0.362), external rotation (rs = −0.11, p = 0.387, ASES score (rs = −0.1, p = 0.133), SST score (rs = 0.1, p = 0.105), and VAS for pain (rs = 0.2, p = 0.08).
Conclusions
This study found that, in primary RSA using a lateralized implant, medialization of glenoid bone-baseplate interface after eccentric reaming does not influence shoulder range of motion, patient-reported outcome scores, postoperative pain scores, baseplate loosening, or glenoid notching. Further studies with more accurate measuring techniques of MBBI and its results upon patient, implant, and surgical variables are warranted.
Shoulder
Arthritis
Glenohumeral
Arthroplasty
Bones
CT-Scan
Outcome Studies

### 19543 Revision rotator cuff repair versus primary repair for large to massive tears involving posterosuperior cuff: comparison of clinical and radiological outcomes

Prashant Meshram1
Bei Liu2
Sang Woo Kim2
Kang Heo2
Joo Han Oh2
1USA
2Republic of Korea
Summary
Revision rotator cuff repair had similar clinical and radiological outcomes to the primary repairs of large to massive posterosuperior tears.
Data
Background
Outcomes of revision rotator cuff repair (rRCR) have conflicting results with a retear rate ranging 50 - 90%. Another group of patients who have unpredictable clinical outcomes are those who undergo primary RCR (pRCR) for large to massive rotator cuff tears (mRCT). The purpose of this study was to compare the clinical outcomes in patients with posterosuperior rotator cuff tear who had a rRCR for tear of any size with those who had a pRCR for mRCT.
Methods
Among patients with posterosuperior cuff tear operated between 2010 and 2017, the clinical outcomes of 46 patients who underwent a rRCR were compared to 106 patients who had a pRCR for mRCT. The mean follow-up was 26.4 months (range, 24–81 months). The difference in patient reported outcomes (PROs) at the final follow-up between the comparison groups was evaluated and compared with previously published minimal clinically important difference (MCID) values. Radiological outcome was evaluated using MRI or ultrasonography at a minimum one-year follow-up. To identify the risk factors for poor ASES score, a multivariate linear regression analysis was performed. A multivariate logistic regression analysis was used to assess the risk factors for healing failure.
Results
The patients in each rRCR and pRCR group had a statistically significant and clinically relevant improvement in PROs and ROM when compared from preoperative to postoperative status at the final follow-up. Comparing the PROs at final follow-up between two groups, the pain VAS (2.1 vs. 1.0, P = 0.004), satisfaction VAS (6.9 vs. 8.6, P < 0.001), and ASES score (79.7 vs. 89.8, P = 0.001) in rRCR group were statistically significantly worse than pRCR group, whereas the Constant score (68.0 vs. 67.8, P > 0.05) was not statistically different between two groups. None of the above differences in PROs were clinically significant as they did not exceed the MCID threshold. The ROM in rRCR group was not statistically significant than pRCR group for flexion (158° vs 163°) and external rotation at 90° (85° vs 89°). The rate of healing failure in the rRCR group was 50% compared with the pRCR group (39%; p=0.194). While comparing PROs within rRCR group, those who had a healing failure at follow up showed significantly worse pain VAS score and ASES score than patients with intact cuff. Risk factors for worse ASES score in patients of rRCR group were healing failure (P=0.043, r=-11.3), lower body mass index (P=0.032, r=1.9), and lower preoperative pain VAS (P=0.038, r=2.3). The risk factors for healing failure in rRCR were preoperative high-grade fatty degeneration (Goutallier grade 3 and 4) of supraspinatus muscle (P=0.026, OR 5.2) and hyperlipidemia (P=0.035, OR 11.8).
Conclusion
Revision rotator cuff repair had similar clinical and radiological outcomes to the primary repairs of large to massive posterosuperior tears. Patients with symptomatic failed rotator cuff repairs having high-grade fatty degeneration of supraspinatus and/or serum hyperlipidemia had a higher likelihood of healing failure after revision repair which was associated with poor functional outcomes. These patients should be considered for an alternative treatment.
Shoulder
Repair/Reconstruction
Tears
Arthroscopy
Glenohumeral
Impingement
Infraespinatus
Infraespinatus Tendon Injury
MRI
Muscle
Outcome Studies
Supraespinatus
Supraespinoatus Tendon Injury
Sutures/Knots/Anchors
Tendon
Ultrasound

### 19474 Value, limitations and recommendations for use of metal-reduction knee MRI sequences following anterior cruciate ligament reconstruction

Brandon Zhao
Nabil Khan
Mark F Sommerfeldt
Anukul Panu
Jacob L Jaremko
Catherine May Ting Hui
Summary
Use of metal artifact reduction sequences (WARP and SEMAC) significantly improved diagnostic accuracy and confidence in detection of ACL graft tears. When the key clinical question is ACL graft integrity, our study supports adding a WARP sequence to the routine knee MRI scan protocol.
Data
Background
No study to date has evaluated the utility of MRI with metal artifact reduction sequencing (MARS) In the assessment of ACL grafts. MRI assessment of ACL graft integrity following ACL reconstruction is challenging due to magnetic susceptibility artifacts distorting or obscuring the graft and tunnels. Purpose To determine whether MRI with MARS is superior to conventional knee MRI in visualization and diagnostic accuracy for ACL graft rupture. Study Design Retrospective case series.
Methods
18 patients, 19 knees (male, 6; female, 12; age, 33 + 11.9 years) who underwent conventional MRI sequence (PD) and two types of MARS MRI (WARP, SEMAC; Siemens) following secondary injury to their ACL reconstructed knee. Six readers with knee MRI experience reviewed sagittal PD, WARP and SEMAC sequences, providing semi-quantitative grades for visualization and diagnostic confidence regarding ACL, PCL, menisci, tibial and femoral tunnel margins, and articular cartilage.
Results
Compared to PD, WARP improved visualization of ACL (mean semi-quantitative score 3.79 vs 3.96, p=0.009), femoral tunnel (3.70 vs 4.01, p=0.001), and tibial tunnels (3.56 vs 3.92, p<0.0001), although at the cost of poorer visualization of femoral articular cartilage (4.70 vs 4.59, p=0.033), tibial articular cartilage (4.70 vs 4.58, p=0.022), medial meniscus (4.75 vs 4.53, p=0.001), and lateral meniscus (4.72 vs 4.56, p=0.026). SEMAC performed similarly to WARP, except that WARP provided significantly better visualization of cartilage and menisci than SEMAC (p<0.00001 each). Diagnostic confidence of ACL integrity was significantly improved over PD for both WARP (1.70 vs 2.17, p = 0.034), and SEMAC (1.70 vs 2.61, p = 0.032). There was no significant difference in diagnostic confidence between WARP and SEMAC (p = 0.071). There was no significant difference in the interobserver reliability between each sequence. The WARP sequence added 2.84 + 0.69 minutes while SEMAC added 2.95 + 0.40 minutes to the standard knee MRI scan time.
Conclusion
Use of metal artifact reduction sequences (WARP and SEMAC) significantly improved diagnostic accuracy and confidence in detection of ACL graft tears. When the key clinical question is ACL graft integrity, our study supports adding a WARP sequence to the routine knee MRI scan protocol.
Knee
ACL
Arthroscopy
Ligaments
Tears
Basic Science
Cartilage
Lateral
Medial
Meniscus
MRI
Practice Management
Repair/Reconstruction

### 19494 Impingement due to graft buckling is more prevalent after ACL reconstructions with an adjustable-loop compared to a fixed-loop

Julian De Rover
Inge Van Den Akker-Scheek
Hugo Christiaan van der Veen
Netherlands
Summary
Impingement Due to Graft Buckling Is more Prevalent after ACL Reconstructions with an Adjustable-Loop compared to a Fixed-Loop
Data
Background
Graft fixation in anterior cruciate ligament (ACL) reconstruction is achieved by interference screws, cortical buttons or combinations of both. The two options for button fixation include a fixed-loop (FL) and an adjustable-loop (AL) device. Both revealed similar clinical outcomes in recent literature, yet reoperation rates have not been studied elaborately. This retrospective cohort study aimed to analyse the reoperation rate, patient reported functional outcome and sensibility disorders after ACL reconstruction using either a fixed-loop or adjustable-loop device.
Methods
344 patients underwent primary ACL reconstruction with autologous hamstring tendon grafts. In 189 patients, gracilis and semitendinosus autografts were used with a femoral fixed-loop button fixation (EndoButton, Smith&Nephew) combined with tibial interference screw fixation. In 145 patients a single hamstring autograft was used combined with both femoral and tibial adjustable-loop button fixation (TightRope, Arthrex). Outcome measures were reoperation rate, Lysholm score, Tegner score, International Knee Documentation Committee (IKDC) score and self-reported sensibility disorders.
Results
Median follow-up was 33.0 and 29.0 weeks in the fixed- and adjustable-loop group, respectively. Reoperation rate was comparable between groups (14.8% in FL, 18.6% in AL; p=.353). Analysis of reoperations due to impingement showed an increased incidence of graft buckling in the adjustable-loop group (10% in FL, 75% in AL; p=.013). Mean Lysholm score (83.1 in FL, 81.6 in AL; p=.466), Tegner score (6.2 in FL, 5.8 in AL; p=.153) and IKDC score (81.5 in FL, 79.1 in AL; p=.287) were comparable between groups, as well as the amount of patients reporting sensibility disorders (17.4% in FL, 19.2% in AL; p=.848).
Conclusion
Reoperation rate was comparable between fixed-loop and adjustable loop groups, however the incidence of impingement due to graft buckling was higher in the adjustable-loop group. Fixed- and adjustable-loop devices showed comparable results at final moment of contact in terms of patient-reported functional outcome and self-reported sensibility disorders. Attention should be paid to an even tensioning of all four strands during graft preparation.
Knee
ACL
Ligaments
Repair/Reconstruction
Tears
Arthroscopy
Autograft
Impingement

### 19651 Outcomes of proximal hamstring tendon repair in patients older than 50 years of age

Alexander Rainer Manuel Bitzer
Daniel Hurwit
Julian Joseph Sonnenfeld
Durham Weeks
USA
Summary
Compare pain relief and functional outcomes in young (<50 years of age) versus older (>50 years of age) after primary proximal hamstring repair
Data
Background
The majority of proximal hamstring tendon tears are treated conservatively with non-operative management. However, patients with certain injury patterns or failure of conservative management may benefit from operative intervention that leads to improved clinical outcomes. The majority of these outcomes have been reported in young and middle aged patients. We hypothesized that patients aged 50 years and older, who undergo primary proximal hamstring repair, would benefit from similar clinical improvements without an increased risk of complications when compared to younger patients.
Methods
A retrospective analysis of prospectively collected data was performed using our institution’s research database. All patients who underwent primary proximal hamstring tendon repair between 2015 and 2019 by a single surgeon were evaluated. Patients were grouped into younger (age 16–49 years) and older (age > 50 years) age cohorts. The primary outcome was patient reported pain (Visual Analog Scale score, VAS). Pre- and post-operative VAS scores were compared between the two cohorts at an average follow-up of 26.3 months. Complications, satisfaction, and return to function were also compared at a minimum of 1-year follow-up. Results A total of 54 patients met the inclusion criteria for this study. The younger cohort included 24 patients (5 male, 19 female) while the older cohort included 30 patients (8 male, 22 female). There were no significant differences in patient characteristics between groups except for age (40.5 years versus 57.8 years, p < .01) At final follow-up, post-operative pain scores were significantly improved in both younger and older patient cohorts compared to pre-operative values (6 ± 1.3 to 1.3 ± 1.5 and 7.6 ± 1.5 to 1.4 ± 2, respectively, p < .001). Older patients had a more significant reduction in pain compared to younger patients after surgical repair (-6.2 ± 2.1 versus −4.75 ± 1.9, p = .01). There was no significant difference in complication rates between groups. Patient satisfaction and return to function was greater than 93% in both groups.
Conclusion
Patients aged 50 and older obtain at least equivalent if not better improvements in functional outcome and pain relief after primary proximal hamstring tendon repair compared to their younger counterparts. Older patients are not at an increased risk for surgical complications after primary hamstring tendon repair.
Hip/Groin/Thigh
Repair/Reconstruction
Tears
Tendon
Elderly
MRI
Outcome Studies
Sport Specific Injuries
Sutures/Knots/Anchors
X-ray

### 19705 Clinical outcomes of rotator cuff repairs in patients with concomitant glenohumeral osteoarthritis

Rajiv Pabbati Reddy
David Solomon
Jonathan D Hughes
Albert Lin
USA
Summary
Rotator cuff repairs in patients with pre-existing glenohumeral osteoarthritis have similar clinical and functional outcomes as repairs in patients without osteoarthritis with the exception of a slightly decreased postoperative FF and ER ROM.
Data
Introduction
Glenohumeral osteoarthritis is a common comorbidity in patients with rotator cuff tears. Management of rotator cuff tears in patients with concomitant glenohumeral osteoarthritis is varied and still heavily debated. Although rotator cuff repairs have been shown to have excellent long-term outcomes in the general population, very few studies have demonstrated their efficacy in patients with preexisting glenohumeral osteoarthritis. Thus, the purpose of this study is to compare the clinical and functional outcome measures following arthroscopic rotator cuff repairs in patients with preexisting glenohumeral osteoarthritis to those without. We hypothesized that failures rates as well as objective and patient reported outcomes would be similar between the two groups.
Methods
A retrospective review of 206 consecutive patients who underwent arthroscopic supraspinatus repairs (both isolated and with accompanying infraspinatus/subscapularis involvement) between 2013–2018 with a minimum of one-year follow up was performed. Patients were separated into two groups based on presence or absence of preexisting glenohumeral osteoarthritis. The groups were controlled for tear pattern, sex, BMI, tobacco/alcohol use, and common co-morbidities. The primary outcome was failure of repair, defined as need for revision repair or a re-tear confirmed on postoperative MRI. Secondary outcomes were patient-reported outcome measures (PROs) including visual analog pain scale (VAS), subjective shoulder value (SSV), and American Shoulder and Elbow Surgeons (ASES) score; active range of motion (ROM), including forward flexion (FF), external rotation (ER), and internal rotation (IR); and strength testing, including FF, ER, and IR. Within the osteoarthritis cohort, a subgroup analysis was conducted to compare outcomes between mild versus moderate to severe osteoarthritis. Outcomes were compared using Mann-Whitney U and Fisher’s Exact Test with p<0.05.
Results
There were 91 patients in the glenohumeral osteoarthritis group and 115 patients in the control group. There was a significant difference in the postoperative FF (153.55 ± 21.07 vs. 160.14 ± 17.26 degrees, p=0.001) and ER (46.91 ± 11.95 vs. 52.25 ± 11.60 degrees, p=0.001) ROM between the glenohumeral osteoarthritis and control groups, respectively. There were no significant differences between groups for revisions repairs, retears, postoperative IR ROM, all preoperative ROM, all PROs, and all strength parameters (all p > 0.05). For the subgroup analysis, there were 70 patients in the mild osteoarthritis group and 21 patients in the moderate to severe osteoarthritis group. There was a significant difference in the postoperative FF strength (88.4% vs. 61.9% with 5/5 strength, p=0.010) and ER strength (89.9% vs. 71.4% with 5/5 strength, p=0.046) between the mild and moderate to severe groups, respectively. There were no significant differences between the groups for all other outcome measures. Discussion: Rotator cuff repair remains an excellent treatment in patients with pre-existing glenohumeral osteoarthritis. The data from this study demonstrates that rotator cuff repairs in patients with pre-existing glenohumeral osteoarthritis have similar clinical and functional outcomes as repairs in patients without osteoarthritis with the exception of a slightly decreased postoperative FF and ER ROM. Patients with moderate to severe osteoarthritis may have slightly decreased FF and ER strength outcomes compared to those with mild osteoarthritis.
Shoulder
Arthroscopy
Glenohumeral
Tears
Osteoarthritis
Outcome Studies

### 19682 The factors influencing postoperative cuff integrity of arthroscopic rotator cuff repair combined with muscle advancement for massive rotator cuff tear

Yasuhiko Sumimoto
Shin Yokoya
Japan
Summary
ISP retraction and TM atrophy may be the key factors for predicting postoperative cuff integrity when arthroscopic rotator cuff repair combined with muscle advancement for massive rotator cuff tear is performed.
Data
Introduction
It is well known that the failure rate after arthroscopic rotator cuff repair (ARCR) in the case of massive rotator cuff tear (mRCT) is high, and that the treatment is often difficult. We have reported that ARCR combined with muscle advancement (MA) can be expected to reduce the failure rate of mRCT treatment. Nevertheless, failure is an inevitable risk, which has obvious negative implications for the clinical outcomes, so it is important to reveal what the potential risk factors are. Hence, our aim in this study was to research the factors that can influence postoperative cuff integrity of ARCR combined with MA for mRCT.
Methods
From October 2011 to September 2020, we examined 68 patients who underwent ARCR with MA for mRCT, and postoperative MRI enabled us to evaluate whether cases healed or failed after surgery. There were 40 males and 28 females, and the average age at surgery was 66.6 ± 8.6 (39–81) years. We passed nylon thread through the supraspinatus tendon (SSP) and infraspinatus tendon (ISP), and pulled it with a tension meter at 30N in a 30 degrees’ abduction position. MA was performed in cases where full coverage of the footprint could not be achieved by the cuff stumps. We evaluated patient background {age, sex, diabetes mellitus (DM)}, preoperative clinical scores (Constant shoulder score, University of California at Los Angeles Shoulder score, Numerical Rating Scale), preoperative X-ray findings (acromiohumeral interval, critical shoulder angle), preoperative MRI findings (rotator cuff retraction size, fatty infiltration, muscle atrophy), and intraoperative findings (Subscapularis tendon injury, long head biceps tendon injury, with or without a polyglycolic acid sheet). These items were divided into the healed group and failed group (Sugaya classification type IV and V were defined as failure by postoperative MRI). Univariate and multivariate logistic regression analysis was performed, and P <0.05 was considered as significant.
Results
Univariate analysis showed the DM, SSP and ISP retraction size, SSP fatty infiltration, global fatty degeneration index, and teres minor muscle atrophy (TM atrophy) to be significantly more pronounced in the failed group than in the healed group. Multivariate analysis showed the ISP retraction size and TM atrophy to be significantly higher in the failed group than in the healed group.
Conclusion
We investigated the factors influencing postoperative cuff integrity of ARCR combined with MA for mRCT. Multivariate analysis showed ISP retraction and TM atrophy to be significantly higher in the failed group than in the healed group. These factors may be crucial for the accurate prediction of postoperative cuff integrity when ARCR is combined with MA for mRCT.
Shoulder
Glenohumeral
Repair/Reconstruction
Tears
Infraespinatus Tendon Injury
MRI
Outcome Studies
Subescapular Tendon Injury
Supraespinoatus Tendon Injury
Tendon
Teres Minor Injury

### 19676 Outcomes of obstructive sleep apnea patients undergoing rotator cuff repair

Andres Barandiaran
Rachel M Frank
Jonathan T Bravman
Eric C McCarty
USA
Summary
Despite controlling for age and BMI, patients with obstructive sleep apnea report worse physical health and shoulder function post-rotator cuff repair compared to healthy patients, despite no pre-operative differences.
Data
Introduction
Obstructive sleep apnea (OSA) prevalence in the general adult population is estimated to be 6–17%, and as high as 49% in older adults. These patients are at 45–59% greater risk of postoperative complications, such as hypoxemia, acute hypercapnia, as well as hyperalgesia, due to higher levels of inflammatory markers compared to patients without OSA. While older adults are at higher risk of OSA, they are also at a higher risk of having a rotator cuff tear (RCT). Previous research has shown 30% of adults >60 years and 62% of adults >80 years have a RCT. Given the prevalence of OSA and RCT in older adults, OSA may negatively affect parameters of mental, physical health, and shoulder function in patients recovering from rotator cuff repair (RCR). The purpose of this study was to compare patient reported outcomes (PROs) between OSA patients and controls that underwent RCR.
Methods
A retrospective review of patients who underwent RCR by 5 fellowship-trained orthopedic surgeons between 2014 and 2019 was performed. Patient medical history was screened for a diagnosis of OSA or deemed at high risk by STOP BANG questionnaire. All patients were asked to complete PROs pre-operatively, at 3, and 6 months post-operatively. A mixed-model ANOVA was performed with age and BMI as covariates due to higher age and BMI increasing OSA risk as well as being associated with worse outcomes following RCR.
Results
Data from 91 (44 female) control and 89 (24 female) OSA patients were available for analysis. As expected as OSA risk increases with male sex, higher BMI, and age; mean BMI (25.1 ± 4.0 kg/m2 vs. 30.4 ± 5.1 kg/m2), age (57.7 ± 11.8 years vs. 61.7 ± 8.7 years), were significantly higher in the OSA group (p<0.05). In addition, there were also significantly less females in the OSA group compared to control (p<0.05). There was no significant effect of OSA for VAS, VR-12 mental scores, and SANE (p>0.05). However, OSA patients had a significantly lower ASES score compared to control (66.79 ± 21.03 vs. 60.95 ± 21.70, respectively, p<0.05) when adjusted for age and BMI, but no interaction effect with time (p>0.05). In contrast, VR-12 physical scores showed a significant interaction effect of time and OSA condition, when adjusted for age and BMI. More specifically, control patients at both 3 months (41.0 ± 1.0 vs. 37.1 ± 1.0, p<0.05) and 6 months (49.2 ± 1.2 vs. 42.3 ± 1.3, p<0.05) reported better physical health post-RCR compared to OSA patients. Lastly, the difference in 6-month VR-12 physical scores between groups met minimal clinical important difference (MCID) criteria.
Conclusion
The findings of our study suggest PROs related to shoulder pain and mental health among OSA patients that underwent RCR are not significantly different from healthy patients. However, our results show despite controlling for age and BMI, patients with OSA report significantly worse physical health post-operatively and shoulder function compared to healthy patients.
Shoulder
Repair/Reconstruction
Tears

### 19761 Blood glucose levels in diabetic patients following intra-articular corticosteroid injection of the shoulder: a pilot study

Andres Barandiaran
Rachel M Frank
Eric C McCarty
Jonathan T Bravman
USA
Summary
Blood glucose levels are significantly elevated following glenohumeral corticosteroid injection during injection day and first four days post-injection when compared to baseline, blood glucose levels return to baseline after 14 days post injection.
Data
Introduction
Intra-articular corticosteroid injection (CSI) is a conservative procedure used in shoulder pain patients to provide rapid relief of shoulder pain. While previous research has shown injections can induce or exacerbate hyperglycemia in patients with uncontrolled diabetes, these studies did not track patients on a daily basis or for longer than seven days. This makes it difficult for clinicians to advise patients on the time period they should monitor their blood glucose levels (BGLs) with increased caution. Hence, this study aimed to observe BGLs in patients with uncontrolled diabetes for 14 days post shoulder CSI.
Methods
We recruited 20 patients with either type I or type II diabetes undergoing treatment for a single glenohumeral CSI. All patients had an HbA1C measurement within the last 3 months. All injections were standardized to a total injection volume of 6 mL, comprised of 5 mL 1% Lidocaine (without epinephrine) and 1 mL of Triamcinolone (40mg/mL). We excluded patients that had a prior CSI or had taken oral steroids 6 weeks prior to their injection date. We obtained baseline measure of BGLs using a glucometer prior to the CSI. Subsequently, we had patients record their BGLs using the glucometer and a diary daily for the first week post CSI, and then every other day for the second week. Descriptive statistics were performed to determine a normal distribution among our dataset, followed by a repeated-measures ANOVA with bonferroni corrections for longitudinal comparisons of BGLs.
Results
20 patients (25% male) measured their BGLs using a glucometer for two weeks post CSI. The mean age was 60.5 ± 13.3 years (range 35–78 years) with a mean BMI of 33.1 ± 7.5 kg/m2 and a mean HbA1C value of 7.7 ± 1.4%. Only 3 patients demonstrated a normal HbA1C level between 4–6%. Mean patient BGLs at baseline were 140.25 ± 8.26 mg/dL. We found BGLs were 68.7% (236.62 ± 14.6 mg/dL) and 91.0% (267.91 ± 16.8 mg/dL) higher on day of injection and post injection day 1 when compared to baseline, respectively (p<0.05). We also found post injections day 2, 3, and 4. were also 72.6% (242.13 ± 16.2 mg/dL), 38.9%(194.92 ± 12.5 mg/dL), and 34.46%(188.59 ± 8.85 mg/dL) higher when compared to baseline, respectively (p<0.05). Lastly, no other subsequent time points were significantly different from baseline (p>0.05).
Discussion
The main finding of our pilot study suggests BGLs are significantly elevated during the injection day and first four post-injection days when compared to baseline, with the highest mean value occurring on the first post-injection day. Our results align with previous research of CSIs significantly increasing BGLs in diabetic patients with HbA1C levels greater than 7% in the first post-injection and injection day. We can extrapolate from our results that two weeks is enough time for BGLs to return to near baseline BGLs in our patient population. In conclusion, diabetic patients with elevated HbA1C should monitor their BGLs more closely after receiving a CSI.
Shoulder
Glenohumeral
Osteoarthritis
Bones
Outcome Studies
Ultrasound

### 19766 What is the ideal position of the shoulder for graft fixation in arthroscopic superior capsular reconstruction? A computational analysis

Carlos Quental
Clara Azevedo
Catarina Ângelo
Portugal
Summary
A computational analysis was designed to determine the role of the fascia lata graft in restoring shoulder stability in arthroscopic superior capsular reconstruction for irreparable rotator cuff tears. Shoulder stability was better restored when the graft was fixed with the shoulder at 5° to 10° of abduction, and in 10° of internal rotation, and when the long head of the biceps was preserved.
Data
Background
Arthroscopic superior capsular reconstruction (ASCR) for the treatment of irreparable rotator cuff tears (IRCTs) has been shown to produce excellent functional outcomes. However, the graft tear rate ranges from 4.2% to 75%. The position of the shoulder during graft fixation may be a key factor impacting the outcome of ASCR, and biomechanical evidence regarding the effect of initial graft positioning on the stability of the shoulder, and on the functional role of the graft is lacking. This study aimed to determine whether the position of the shoulder during graft fixation influences the stability of the shoulder and graft tear risk. The hypotheses were that ASCR would increase the stability of the shoulder after an IRCT, and different positions of the shoulder during graft fixation would influence shoulder stability and graft tear risk.
Methods
A musculoskeletal model of the upper limb was modified to account for the fixation of the graft. A total of 126 shoulder positions of fixation were simulated to improve shoulder stability. The material properties of the graft were defined based on experimental data that the authors had collected previously from 20 cadaveric fresh fascia lata grafts. The rotator cuff tear was modelled assuming a full-thickness tear of the supraspinatus tendon. The effect of concomitant long head of the biceps (LHB) tenotomy was also studied. The biomechanical parameters evaluated included the strain of the graft and the glenohumeral joint reaction force, to estimate the integrity of the graft and shoulder stability, respectively. The positions of high risk of tear were defined as those for which the strain of at least one segment of the graft exceeded the strain failure of 15%. Analysis of variance (ANOVA) and Tuckey’s test were used to compare the shoulder stability index among shoulder positions of fixation. The significance level was set to p < 0.05.
Results
Fixation at abduction angles of >15° resulted in a high risk of graft tear when the arm returned to the resting position. For this reason, the stability of the shoulder, for these positions, was not evaluated. Shoulder stability significantly improved compared with the preoperative condition, regardless of the shoulder position of fixation (95% confidence intervals, p<0.001). Fixation of the graft with the shoulder at 5° to 10° of abduction and in 10° of internal rotation correlated with the most significant improvement in shoulder stability compared to the preoperative condition (p<0.001). Concomitant tenotomy of the LHB significantly decreased shoulder stability of ASCR (p=0.007).
Conclusion
ASCR for IRCTs increases the stability of the shoulder compared to the preoperative condition. Fixing the superior capsular graft with the shoulder at 5° to 10° of abduction, and in 10° of internal rotation, and without concomitant LHB tenotomy, improves shoulder stability. Abduction angles >15° increase the graft tear risk. This study supports the relevance of the position of the shoulder during graft fixation both for the stability of the shoulder, and for graft integrity after ASCR. New studies should investigate the role of LHB tenodesis as an alternative to tenotomy to preserve the LHB’s stabilizing effect in ASCR.
Shoulder
Autograft
Glenohumeral
Tears
Arthroscopy
Basic Science
Biomechanics
Capsuloligamentous Complex
Repair/Reconstruction
Supraespinoatus Tendon Injury
Tendon

### 19768 Acl deficiency influences medio-lateral tibial alignment and knee varus-valgus during in vivo activities

Piero Agostinone
Stefano Di Paolo Eng
Alberto Grassi
Marco Bontempi
Erika Pinelli
Laura Bragonzoni
Stefano Zaffagnini
Italy
Summary
Dynamic radiostereometry evaluation of ACL deficiency
Data
Purpose
The role of the anterior cruciate ligament (ACL) in knee biomechanics in vivo and under weight-bearing is still unclear. The purpose of this study was to compare the tibiofemoral kinematics of ACL-deficient knees to healthy contralateral ones during the execution of weight-bearing activities.
Methods
Eight patients with isolated ACL injury and healthy contralateral knees were included in the study. Patients were asked to perform a single step forward and a single leg squat first with the injured knee and then with the contralateral one. Knee motion was determined using a validated model-based tracking process that matched subject-specific MRI bone models to dynamic biplane radiographic images, under the principles of Roentgen stereophotogrammetric analysis (RSA). Data processing was performed in a specific software developed in Matlab.
Results
Statistically significant differences (p < 0.05) were found for single leg squat along the frontal plane: ACL-deficient knees showed a more varus angle, especially at the highest knee flexion angles (40°–50° on average), compared to the contralateral knees. Furthermore, ACL-deficient knees showed tibial medialization along the entire task, while contralateral knees were always laterally aligned. This difference became statistically relevant (p < 0.05) for knee flexion angles included between 0° and about 30°.
Conclusion
ACL-deficient knees showed an abnormal tibial medialization and increased varus angle during single leg squat when compared to the contralateral knees. These biomechanical anomalies could cause a different force distribution on tibial plateau, explaining the higher risk of early osteoarthritis in ACL deficiency. The clinical relevance of this study is that also safe activities used in ACL rehabilitation protocols are significantly altered in ACL deficiency.
Knee
ACL
Ligaments
Tears
Biomechanics
MRI
X-ray

### 19738 Evaluation of rotator cuff repair with and without concomitant biceps treatment: a retrospective review of patient outcomes

Daniel Nemirov
Sommer Hammoud
Meghan E Bishop
Zachary J Herman
Ryan W Paul
Ari Clements
Matthew Beucherie
Michael G Ciccotti
Kevin Freedman
Brandon Erickson
USA
Summary
The purpose of this study is to retrospectively compare the clinical outcomes between patients who underwent isolated RCR versus patients who underwent RCR with concomitant biceps treatment. Correcting biceps pathology when performing RCR results in similar rates of cuff failure, revision RCR, complications, and pre- to post-operative change in ASES scores when compared to isolated RCR.
Data
Bicipital pathology is common in patients with rotator cuff tears. Leaving biceps pathology untreated in rotator cuff repairs (RCR) may lead to suboptimal outcomes. The purpose of this study is to retrospectively compare the clinical outcomes between patients who underwent isolated RCR versus patients who underwent RCR with concomitant biceps treatment. In patients that received biceps treatment, we sought to compare (1) biceps tenodesis versus biceps tenotomy and (2) sub-pectoral tenodesis versus arthroscopic tenodesis.
Methods
A retrospective chart review of 244 patients who underwent RCR at a single multicenter institution in 2016 was performed. Patient demographics, presence of concomitant biceps pathology, pre- and postoperative American Shoulder and Elbow Surgeons (ASES) scores, rates of rotator cuff failure, revision surgery, and all complications were compiled.
Results
101 patients underwent RCR with concomitant tenotomy (n=30) or tenodesis (n=71) for biceps treatment and 143 underwent RCR alone. Patients undergoing biceps treatment were older (59.1 years vs. 56.3 years; p=0.013) and more likely to be male (45.7% vs. 30.4%; p=0.029). Patients undergoing biceps treatment were more likely to have a subscapularis tendon repair (43.6% vs. 11.2%; p=<0.001). Preoperatively, biceps treatment patients had lower ASES scores (41.2 vs 49.3; p=0.003). Postoperatively, there was no significant difference in ASES scores (79.5 biceps treatment vs. 81.5 isolated RCR; p=0.532). There was no significant difference in rates of cuff failure (p=0.766), revision RCR (p=0.703), or all complications (p=0.102) after 2 years. There was no significant difference in average age (61.6 vs 58.1 years; p=0.054) in the tenotomy versus tenodesis groups. Males were more likely to have tenodesis than females (76% vs. 48%; p=0.011). There were significantly lower preoperative ASES scores in the tenotomy group compared to the tenodesis group (34.3 vs 44.0; p=0.036). Postoperative ASES scores were not significantly different between groups (73.5 tenotomy vs 82.1 tenodesis; p=0.149). There were no significant differences in rates of cuff failure (p=1.000), revision RCR (p=1.000), or all complications (p=1.000) after 2 years. There was no significant difference in age between patients having subpectoral tenodesis (n=21) and those having arthroscopic tenodesis (n=50) (55.0 vs 59.4 years; p=0.058). Patients in the arthroscopic group were more likely to undergo subscapularis repair (52% vs. 40%; p=0.045). There were no significant differences in preoperative ASES between the arthroscopic and subpectoral tenodesis groups (41.1 vs. 50.4; p=0.066). Postoperative ASES scores were not significantly different (83.2 arthroscopic vs 79.6 subpectoral; p=0.592). There was no significant difference in rates of cuff failure (p=1.000), revision RCR (p=0.507), or all complications (p=1.000) after 2 years.
Conclusions
Addressing biceps pathology when performing RCR resulted in similar rates of cuff failure, revision RCR, complications, and improvement in patient-reported outcomes when compared to isolated RCR at two-years postoperatively. Furthermore, when comparing tenotomy versus tenodesis and arthroscopic versus subpectoral tenodesis, comparable outcomes with regards to rate of rotator cuff repair failure, revision RCR, complications, and patient-reported outcomes were found.
Orthopaedic Sports Medicine
Outcome Studies
Repair/Reconstruction
Tears
Shoulder

### 19897 Coronal plane knee joint line slope moves contact areas and loads the menisci post osteotomy

Dong Wang1
Lukas Willinger2
Kiron K Athwal1
Andy Williams1
Andrew A Amis1
1UK
2Germany
Summary
Measures the effects of medial-lateral slope post-osteotomy, leading to loading of the menisci and moving cartilage contacts with tibiofemoral subluxation.
Data
Introduction
There is little scientific evidence on the effect of knee joint line obliquity (JLO) before and after coronal re-alignment osteotomy. Bony alignment of the knee joint is an important factor in its normal function, different pathologies, and load distribution. There is little evidence on how coronal JLO affects joint pressure, shear forces, and joint movement when weight bearing. There is no clearly accepted JLO cut-off defined, to facilitate the indication of either single-level or double-level osteotomies. It is generally accepted that 10° of JLO is the arbitrary upper limit accepted for osteotomy surgery. Hypotheses: It was hypothesized that higher JLO would lead to abnormal relative position of the femur on the tibia, a shift of the joint contact areas, and elevated joint contact pressures.
Study design
Descriptive Laboratory Study
Methods
10 fresh-frozen human knees (age 59 ± 5 years) were axially loaded to 1500N in a materials testing machine with the joint line tilted 0°, 4°, 8° and 12° varus (‘downhill’ medially) and valgus, at 0° and 20° knee flexion, simulating weight-bearing gait. The mechanical compression axis was aligned to the center of the tibial plateau. Contact pressure and contact area were recorded by pressure sensors inserted between the tibia and the menisci. Changes in relative femoral and tibial position in the coronal plane were obtained by an optical tracking system. Data were analyzed by repeated-measures ANOVA with post-testing.
Results
Both medial and lateral JLO caused significant tibiofemoral subluxation and pressure distribution changes. Medial (varus) JLO caused the femur to sublux medially down the coronal slope of the tibial plateau, and vice-versa for lateral (valgus) downslopes (P<0.01), giving 6 mm range of subluxation. The areas of peak pressure moved more than the bone subluxations, by 12 mm and 8 mm across the medial and lateral condyles, onto the ‘downhill’ meniscus and the ‘uphill’ tibial spine. The loaded meniscus acted as a sling to resist further subluxation. Changes in JLO had only small effects on mean and maximum contact pressures.
Conclusions
A 4° change of JLO during load bearing causes significant mediolateral tibiofemoral subluxation. The femur slides down the slope of the tibial plateau to abut the tibial eminence and also to rest on the ‘downhill’ meniscus. This causes large movements of the tibiofemoral contact pressures across each compartment. Clinical relevance: These results provide important information for understanding the consequences of creating coronal JLO, and for clinical practice in terms of osteotomy planning regarding impact on JLO. It provides guidance regarding the choice of single- or double-level osteotomy. Excessive JLO alteration may cause abnormal tibiofemoral joint articulation and chondral/meniscal loading. What this study adds to existing knowledge: This study provides biomechanical in-vitro data on the effect of changing JLO on tibio-femoral subluxation and pressure distribution changes. Furthermore it shows how the menisci and tibial eminences resist movements of the femur in the coronal plane in abnormal JLO along with an increase in stress at these areas. This is important to consider when performing osteotomy especially in the athletically active patients.
Knee
Bones
Osteoarthritis
Osteotomy
Biomechanics
Cartilage
Lateral
Medial
Meniscus

### 19951 Inlay total shoulder arthroplasty for the treatment of advanced glenohumeral arthritis in powerlifters and bodybuilders; “the return to lift”

Luis A Vargas
John W Uribe
John E Zvijac
Kevin Allan West
Matthias Schurhoff
Kristina Kuklova
USA
Summary
Stemless non-spherical humeral head and inlay glenoid replacement provide substantial pain relief and functional improvement and is a promising option for the management of symptomatic osteoarthritis in this challenging patient population. The procedure allows for a return to activities without restrictions
Data
Background
High-level bodybuilders and powerlifters are at risk to develop symptomatic glenohumeral arthritis (GHA) due to the excessive demands placed on their shoulders. Upon failure of conservative management, surgical treatment options are limited and pose clinical challenges due to a relatively young patient age combined with the desire of sport continuation. Arthroscopic management is limited, and stemmed arthroplasty remains controversial due to high glenohumeral stresses upon return to sport.
Hypothesis/Purpose
The purpose of this study was to assess inlay total shoulder arthroplasty (inlay TSA) utilizing a stemless non-spherical humeral head and inlay glenoid (IG) replacement for the treatment of advanced GHA in competitive and high-level recreational strength athletes.
Study Design
Prospective Case Series.
Methods
18 shoulders in 14 male athletes with a mean age of 45.6 years (range 25–57) were included in this study. Pre- and postoperative evaluations included physical and radiographic assessment, patient reported outcomes (PRO) (ASES, WOOS, VAS-P), range of motion (ROM), patient satisfaction, and return to sport.
Results
All procedures were performed on an outpatient basis. No intraoperative complications occurred, and no blood transfusions were required. The mean follow-up was 38 months (range: 25–51). The average ASES improved from 26-93, WOOS from 18-87, and VAS-P from 9-1. The mean ROM increased from 115-145 degrees (forward flexion), from 30–60 degrees (external rotation), and from the level of the sacrum to L3 (internal rotation). Radiographic analysis at last follow-up showed no evidence of component loosening, glenoid migration, or signs of device failure. All patients were satisfied with the procedure and 12/14 returned to moderate or high level of weightlifting. One patient developed arthrofibrosis and required an arthroscopic capsular release and debridement which significantly improved function. Four patients decided to undergo inlay TSA on their symptomatic contralateral side within 6 months of their index procedure.
Conclusions
Stemless non-spherical humeral head and inlay glenoid replacement provide substantial pain relief and functional improvement and is a promising option for the management of symptomatic osteoarthritis in this challenging patient population. The procedure allows for a return to activities without restrictions and leaves multiple arthroplasty options if revision becomes necessary.
Shoulder
Arthroplasty
Glenohumeral
Osteoarthritis
Cartilage
Cartilage Injuries
CT-Scan
Exercise Physiology
Implant
MRI
Outcome Studies
Professional Athletes/Olympians
Sport Specific Injuries
Sport Specific Population
Total Joint Replacement
X-ray

### 20085 Inlay total shoulder arthroplasty for primary glenohumeral arthritis

John W Uribe
John E Zvijac
Luis A Vargas
David A Porter
Anshul Saxena
Matthias Schurhoff
Andrew Payomo
USA
Summary
Treatment with inlay total shoulder arthroplasty demonstrated meaningful functional improvement, excellent pain relief, and patient satisfaction in patients with advanced shoulder arthritis and various glenoid stages
Data
Background
Anatomic total shoulder arthroplasty (TSA) with a non-spherical humeral head and inlay glenoid replacement has been introduced in the past, however clinical evidence remains limited. We hypothesized that patients with advanced glenohumeral arthritis demonstrate meaningful improvements.
Methods
Prospective patient-reported outcomes (PRO) included the American Shoulder and Elbow Surgeons Score (ASES), a pain visual analog scale (VAS-Pain), and satisfaction. Range of motion was compared to the preoperative status. A sensitivity analysis examined responder rates (RR) to literature TSA thresholds for minimal clinically important difference (MCID) and substantial clinical benefit (SCB). Glenohumeral staging and implant stability with zone-specific periprosthetic radiolucency were performed radiographically.
Results
Thirty-nine shoulders in 36 patients (3 bilateral) with a mean age of 65.9 years (26 males, 13 females) and a mean follow-up of 41.0 months, were included. 93% had Grade III osteoarthritis, 7% Grade II. Glenoid stages included A1 (25%), A2 (25%), B1 (22%), B2 (25%,) and C (3%). All PROs improved significantly (p<.001) with a mean ASES from 30.4–77.1, a VAS-Pain from 8.1–1.5, and excellent (9.1/10) patient satisfaction. PRO related RRs for MCID and SCB were >85%. Forward elevation improved from 106.50–154.90, and external rotation from 21.90-50.80. One intraoperative glenoid rim fracture led to advanced radiolucency; no other clinically relevant radiolucency was observed.
Conclusion
Treatment with inlay total shoulder arthroplasty demonstrated meaningful functional improvement, excellent pain relief, and patient satisfaction in patients with advanced shoulder arthritis and various glenoid stages. Our initial evidence provides further support for this new option in primary shoulder replacement.
Shoulder
Arthroplasty
Glenohumeral
Osteoarthritis
Cartilage
CT-Scan
Elderly
Evidence Based Medicine
Implant
MRI
Outcome Studies
Physical Examination
Professional Athletes/Olympians
Total Joint Replacement
X-ray

### 20126 Hip disorders in bull riders: clinical observations and outcomes of arthroscopy

JW Thomas Byrd
Kay S Jones
USA
Summary
Outcomes of hip arthroscopy among bull riders are often favorable, despite common findings of restricted motion, grade IV chondral damage and Tönnis 2 radiographic changes.
Data
Introduction
Restricted range of motion, grade 4 chondral damage, and Tönnis radiographic changes greater than 1 are considered harbingers of poor outcome and possibly contraindications to hip arthroscopy. However, all of these findings are almost uniformly present among bull riders seeking treatment. The purpose of this study is to report on clinical observations in this population and outcomes of arthroscopic intervention, and how these observations may reflect on care in other cohorts.
Methods
Discussion and Conclusion
Bull riders tend to be small framed like jockeys built for bulls. Tight hips associated with FAI may be a serendipitous adaptation for bull riders, providing a static (clothes pin) method for the thighs to grip the bull’s girth. Bull riders undergoing hip arthroscopy commonly carry a triple threat of predictors of poorer results: (1) Restricted motion, (2) grade 4 articular changes, and (3) Tönnis 2 radiographic findings. Despite these, with proper selection, they can often benefit substantially from arthroscopic intervention. Understanding the limits in this challenging population may help in deciphering the potential role of arthroscopy for challenging cases in other patient mixes.
Hip/Groin/Thigh
Arthroscopy
CT-Scan
Evidence Based Medicine
Impingement
Instability
MRI
Osteoarthritis
Outcome Studies
Physical Examination
Professional Athletes/Olympians
Sport Specific Injuries
Sport Specific Population
Stiff Joints
Tears
Trauma
X-ray

### 20016 Novel solution using viable cartilage allograft for focal cartilage defects

Deryk G Jones
Bhumit Desai
Emmanuel Koli
Michael Warren
Gerard Karl Williams
Graylin Jacobs
Walter Stephen Choate
Scott C Montgomery
Misty Suri
USA
Summary
Clinical studies show VCA can safely treat chondral defects with potential advantages to existing options.
Data
Background
Viable Cartilage Allograft (VCA) contains cryopreserved viable allogeneic cartilage fibers mixed with chondrogenic matrix. In-vitro and animal studies and a prospective case series were completed with VCA to assess safety and benefits in treating focal knee cartilage defects. Our hypothesis is that VCA is a safe single stage procedure in isolated chondral defects with results comparable or better than other single stage procedures.
Methods
Cell viability and functionality of VCA was evaluated in-vitro. VCA was also evaluated in a goat cartilage repair model. 19 patients (7/12 M/F) were implanted, mean age 26.77 (15–56), mean BMI 27.59 ± 6.1, mean follow-up 19 months (range 12.0–26.3 months). Symptomatic International Cartilage Repair Society (ICRS) grade 3/4A lesions of the femoral condyle (n=4) or patella (n=14) were treated. Lesion sizes ranged from 1.4–6.0 cm2 (mean defect size was 5.025 cm2). International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome (KOOS) subscales, Lysholm, Short Form-12 (SF-12), visual analog scale (VAS) and pain frequency levels were assessed. Radiographs and magnetic resonance imaging (MRI) were performed at 3 and 6 months (M).
Results
In vitro assessment confirmed VCA contains viable and functional chondrocytes. The goat study confirmed VCA is effective for cartilage repair. Lysholm (25.3), KOOS: Pain (12.2), Symptoms (19.6), ADLs (14.5), Sports (13.7), and QOL (28.9) at 6 months increased from pre-operative baseline (POB) and were maintained at 12 months: IKDC (72.2), Lysholm (84.2), KOOS: Pain (87.8), Symptoms (80.7), ADL (97.6), Sports (72), and QOL (61.2). MRI imaging at 6 and 12 months showed viable preliminary cartilage tissue with no significant bone edema or graft delamination. Second look arthroscopy (2 patients) demonstrated complete fill and incorporation (Brittberg Scores 11/12). Functional scores improved at 24(M): IKDC (87.3), Lysholm (87.7), KOOS: Pain (92.5), Symptoms (86.2), ADLs (95.6), Sports (82.9), QOL (82.1).
Conclusion
VCA is an off-the-shelf, single stage, conformable allogeneic graft that treats chondral defects with no additional fixation. Pre-clinical and short-term prospective clinical studies show VCA can safely treat chondral defects with potential advantages to existing options.
Knee
Biologics
Cartilage
Tears
Cartilage Injuries
MRI
Outcome Studies

### 20203 Assesment of the anterolateral ligament by magnetic resonance imaging is a predictor for failure in the anterior cruciate ligament reconstruction

David H Figueroa
Maria Loreto Figueroa Berrios
Rodrigo Guiloff
Nicolas Zilleruelo
Francisco Figueroa
Alex Vaisman
Chile
Summary
The visualization of an ALL tear in MRI increases the rate of failure of an isolated primary ACL-R.
Data
Introduction
The anterolateral ligament (ALL) of the knee has been described as playing a leading role in anterolateral rotational stability; however, clinical evidence is currently lacking to support clear indications for lateral extra-articular procedures as an augmentation to ACL reconstruction.(ACL-R)
Objective
To evaluate, in ACL injuries, the association between visualization of ALL tears in magnetic resonance imaging (MRI) and failure of an isolated primary ACL-R Hypothesis Visualization of an ALL tear in MRI is associated with a higher rate of failure of isolated primary ACL-R.
Methods
Retrospective case-control study. Eighty-four patients (86 knees) with isolated primary ACL-R operated by the same surgical team with a complete imaging study where included, consisting of 43 knees with ACL reconstruction failure (cases) and 43 knees without it (controls). Patients with multi-ligamentary injuries, articular cartilage procedures and malalignment requiring correction were excluded. A musculoskeletal radiologist blind to the study underwent a pilot screening of sensitivity and specificity for the visualization of ALL tears, according to thickness and signal of the ligament in MRI. Patients with ACL tear and under anesthesia pivot shift examination +++/+++ in which anterolateral plasty/reconstruction was performed were considered positive. Patients examined under anesthesia with a pivot shift -/+++ and without anterolateral plasty/reconstruction were considered negative. Subsequently, the visualization of the ALL, presence of tears and degree of injury were evaluated in all patient’s images of the primary ACL injury. The statistical analysis included logistic regression to calculate Odds Ratio (OR) between ALL tear and failure of the ACL-R. A power of 80% and significance of 5% were considered.
Results
The sensitivity and specificity of the musculoskeletal radiologist for ALL tears was 67% and 63% respectively. Of the 86 MRIs analyzed, it was possible to visualize part of the ALL in 100% of the patients and the entire ligament in 34,9%. In case group (ACL-R failure) a 59% had an ALL tear on the MRI of the primary injury. In control group (without ACL-R failure) 26% presented an ALL tear on the MRI of the primary injury. An ALL tear on MRI was significantly associated with an ACL-R failure with an OR of 2.4 (p=0.05).
Conclusions
The visualization of an ALL tear in MRI increases the rate of failure of an isolated primary ACL-R.
Orthopaedic Sports Medicine
Instability
Repair/Reconstruction
Sport Specific Injuries
ACL
Anterolateral Ligament
Knee
Ligaments
MRI
Sport Specific Population

### 20168 Isokinetic foot strength after peroneus longus tendon autograft harvest

Arumugam Sivaraman
Suresh Perumal
Arvind Shanmugam
India
Summary
Isokinetic strength testing of ankle and sub taller joints after the harvest of Peroneus Longus tendon for cruciate ligament reconstruction shows no significant deficit.
Data
Background
The peroneus longus tendon has been used as a graft in orthopaedic reconstruction surgery because of its comparable biomechanical strength with the native cruciate ligaments and hamstring tendon. However, one of the considerations in choosing an autograft is donor site morbidity.
Purpose/Hypothesis
This study aimed to identify the isokinetic strength of ankle dorsiflexion/plantarflextion and eversion/inversion. The study hypothesis was that strength measurements will be different between the harvest site and contralateral healthy site.
Methods
Patients who underwent peroneus longus tendon autograft harvest for cruciate ligament reconstructions between March 2018 and December 2019 were included in this study. Patients followed a rehabilitation protocol from the first day after surgery. Ankle and subtalar joints movements and its isokinetic strength measured using biodex system 3 isokinetic dynamometer at one year follow up. Donor site morbidity was assessed 6 months and one year after surgery using the VASFA score and American Orthopaedic Foot & Ankle Society (AOFAS) scoring system.
Results
A total of 24 patients (20 male, 4 female; mean age- 32.8 years) fulfilled the inclusion criteria. There was no significant difference in ankle inversion/eversion strength deficit at the donor side compared with the contralateral side (P = .85), with 21 out of 24 patients had less than 10% deficit of contralateral side. Also, there was no significant difference in ankle dorsiflexion and plantar flexion strength at the donor site compared with the contralateral site (P = .51), with 23 out of 24 patient had less than 10% deficit compared to normal side. The mean dorsiflexion strength measured with dynamometer at 60 degree/sec was 59.65 at involved side where as it was 66.65 in normal side (P=0.001). The mean eversion strength measured at 60 degree/sec was 17.66 at involved side where as it was 18.36 in normal side (P=0.0001) The 91.6% of patients had excellent results in AOFAS/VAS score (mean score- 93.7/98.11) at the donor site at one year follow up.
Conclusion
Isokinetic strength of ankle and subtalar joints was similar to those at the contralateral healthy site, with no donor site morbidity. This suggests that the peroneus longus tendon autograft harvest does not significantly alter the foot biomechanics. hence it’s a safer choice of graft for multiple ligament reconstructions.
Ankle/Foot/Calf
Autograft
Instability
Tendon
Biomechanics

### 19964 Long-term outcomes of arthroscopic debridement with or without drilling for osteochondritis dissecans of the capitellum in adolescent baseball players: A =10-year follow-up study

Tetsuya Matsuura
Toshiyuki Iwame
Kenji Yokoyama
Koichi Sairyo
Japan
Summary
Long-term outcomes are durable regardless of lesion size.
Data
Purpose
To evaluate the long-term clinical outcomes of arthroscopic debridement for capitellar osteochondritis dissecans (OCD) in adolescent baseball players.
Methods
This retrospective study evaluated clinical outcomes of arthroscopic debridement for capitellar osteochondritis dissecans in adolescent baseball players seen between 2003 and 2006. Inclusion criteria were at least 10 years of follow-up after surgery. Exclusion criteria were prior elbow surgery and age <12 years or >19 years. Patients were examined for presence of pain, inflammation (effusion), and range of motion (ROM). Outcome measures were determined using Timmerman/Andrews scores. Defect severity on preoperative radiographs was classified into 3 grades: small, moderate, and large. Return to baseball, pre- and postoperative ROM and Timmerman/Andrews elbow score were evaluated according to defect severity.
Results
Twenty-three elbows of 23 baseball players (mean age, 14.7 [range, 13–17] years) underwent arthroscopic debridement for capitellar OCD. Mean follow-up duration was 11.5 (range, 10–13) years. Twenty patients (87%) returned to competitive baseball at their preoperative level; of these, 15 were non-pitchers and returned to the same position but only 1 of 5 pitchers returned to playing pitcher. One patient with a large defect and drilling underwent reoperation 11 years after the initial operation. Mean change in extension was 4.3° and that in flexion was 3.7°. Timmerman/Andrews score improved significantly from 160 (95% confidence interval 146.7–173.3) to 195 (95% confidence interval 185.2–204.8) at the most recent follow-up (p?.0001). Osteochondral defects detected on preoperative radiographs were small in 10 patients, moderate in 7, and large in 6. There was no significant between-group difference in extension, flexion, or Timmerman/Andrews score preoperatively or at the most recent follow-up.
Conclusions
Arthroscopic debridement with or without drilling allowed return to play in adolescent baseball players for positions other than pitchers. Long-term outcomes are likely durable regardless of lesion size.
Elbow/Wrist/Hand
Arthroscopy
Joints
Cartilage
Osteoarthritis
Osteochondritis
Ostheoarthritis
Outcome Studies
Sport Specific Injuries
Sport Specific Population
X-ray

### 20094 Low complication and redislocation rates are evident following patellar stabilization surgery

Laurie A Hiemstra
George A Reed
Sarah Kerslake
Summary
This study demonstrated low complication (7.4%) and redislocation (5.0%) rates following patellar stabilization procedures that included an MPFL reconstruction.
Data
Background
Medial patellofemoral ligament (MPFL) reconstruction has demonstrated a very high success rate with improved patella stability, physical function, and patient-reported outcomes. Systematic reviews have demonstrated a very low redislocation rate, ranging from 2.1–5.1%. Previous studies have also reported a complication rate of up to 26.1% following MPFL surgery.
Purpose
The purpose of this study was to assess the complication rate as well as the number of subsequent surgical procedures in patients with recurrent lateral patellofemoral instability following a patellar stabilization surgery including an MPFL reconstruction.
Methods
Patients with recurrent patellofemoral instability who underwent a patellofemoral stabilization including an MPFL reconstruction (n = 363) were assessed at a minimum of 2-years post-operative. Of the 363 patients, 98 (27%) underwent a contralateral surgery during the study period, providing data for 461 knees. Pathoanatomic risk factors were assessed pre-operatively. Complications and redislocations as well as additional operative procedures were recorded. Disease-specific quality of life was assessed with the Banff Patellofemoral Instability Instrument (BPII). Descriptive statistics including rates, means, and standard deviations were calculated.
Results
Complications following surgery were recorded in 34/461 knees (7.4%). Redislocation of the patella occurred in 23/461 knees (5.0%). There were three deep infections and one superficial infection, five knees developed arthrofibrosis, there was one tibial tubercle fracture, and one non-union of a femoral osteotomy. There were no patella fractures, incorrect femoral tunnel placement, medial dislocations, implant failures, deep vein thromboses or pulmonary emboli. A subsequent surgical procedure was performed in 94/461 knees (20.4%), with 120 procedures completed in total. Subsequent surgeries included hardware removal in 54 knees (45% of additional procedures), knee arthroscopy in 39 knees (32.5%) and revision patellar stabilization procedures in 23 knees (19.2%). The most common reason for knee arthroscopy was pain secondary to chondral cartilage injury. The mean pre-operative BPII score was 25.5 (SD 13.4), and post-operatively was 65.7 (SD 14.6).
Conclusion
This study demonstrated a low overall complication rate of 7.4% following patellar stabilization using an à la carte approach to surgical treatment. The most common complication was re-dislocation in 5.0% of knees. Additional surgery was performed in 20.4% of knees, of which almost half was expected for removal of hardware. These results indicate a low complication and redislocation rate following patellar stabilization procedures that included an MPFL reconstruction.
Knee
Instability
Patellofemoral
Repair/Reconstruction
Outcome Studies
Patellofemoral Ligament Rupture
Physical Examination
Recurrent Subluxation and Dislocation

### 20120 Generalized Joint Hypermobility More Common in Surgical Failure Cases after Patellofemoral Stabilization

Laurie A Hiemstra
Mark Lafave
Sarah Kerslake
Summary
This study reports a surgical failure rate for patellofemoral stabilization of 4.8%, with the sole risk factor statistically associated with graft failure being generalized ligamentous laxity.
Data
Background
Recurrent patellofemoral instability is a common knee problem for which medial patellofemoral ligament (MPFL) reconstruction with or without concomitant procedures has been shown to effectively and consistently improve function and quality of life outcomes. Management of patellofemoral instability is difficult due to the varying combinations of demographic and pathoanatomic risk factors that present and the controversy regarding the thresholds used to determine the need for concomitant procedures. Examination of surgical failures in this complex patient population is necessary to guide surgical management and develop an understanding of the interplay of these anatomic and biomechanical risk factors.
Purpose
The purpose of this study was to report and analyze the surgical failure rates for patellofemoral stabilization in a large patient cohort. The secondary purpose was to compare the presence of risky demographic and pathoanatomic risk factors in the surgical failures compared with successful stabilizations. Finally, cases of re-dislocation were analyzed to identify the most probable cause for failure.
Methods
This is a prospective case series of 590 knees with symptomatic recurrent patellofemoral instability that underwent a surgical patellofemoral stabilization between June 2008 and February 2017. All patients received an MPFL reconstruction with concomitant procedures performed when indicated to address significant pathoanatomic risk factors. Surgical failure was defined as re-dislocation of the patella. Patients with a successful stabilization procedure were compared to those with a surgical failure using Chi-squared or t-tests for demographic and pathoanatomic variables. The surgical failures were analyzed to determine the probable cause of failure.
Results
A total of 590 patellar stabilization procedures with a minimum follow-up of 24 months (range 24–137) were assessed. There were 28 re-dislocations of the patella for a surgical failure rate of 4.8%. The only risk factor associated with failure was generalized joint hypermobility (Beighton score >5 (2.8) compared to <4 (2.9); p<0.01). The probable causes of failure were generalized joint hypermobility and trochlear dysplasia. The most common revision procedures were isolated MPFL reconstruction revision, MPFL reconstruction revision with tibial tubercle osteotomy, and MPFL reconstruction revision with trochleoplasty.
Conclusions
This study reports a surgical failure rate for patellofemoral stabilization of 4.8% in a large single surgeon cohort. The only risk factor statistically associated with graft failure was generalized joint hypermobility. Overall, patellofemoral stabilization procedures provide good clinical results with very low failure rates. This information may be used to guide surgical decision-making and patient education in this complex patient population.
Orthopaedic Sports Medicine
Dislocation
Outcome Studies
Repair/Reconstruction
Knee
Patellofemoral
Patellofemoral Ligament Rupture
Physical Examination
Recurrent Subluxation and Dislocation

### 20251 Patient satisfaction and functional outcomes of multiple joint replacements: a survey study of patients who have undergone total shoulder, total hip, and total knee

Joseph Michael Brutico
Justin E Palm
Lasya Rangavajjula
Somnath Rao
Steven B Cohen
James X Liu
USA
Summary
Patient satisfaction following total joint replacement of the shoulder, hip, and knee for osteoarthritis.
Data
Introduction
The number of patients who will undergo joint replacement of the shoulder, hip, and knee is expected to increase drastically in the next decade. While previous studies have examined patient satisfaction and postoperative recovery following total joint arthroplasty, no study has compared patient satisfaction and postoperative recovery in a single patient who has undergone total arthroplasty of the shoulder, hip, and knee. The purpose of this study is to determine which joint arthroplasty results in the greatest improvement in quality of life and provides the least painful and difficult recovery.
Methods
Patients diagnosed with arthritis who electively underwent at least one total shoulder arthroplasty (TSA), total knee arthroplasty (TKA) and total hip arthroplasty (THA) over an eighteen-year period, 2000–2018, were identified and included in our analysis. Patients were contacted over the phone to complete the Modified Harris Hip Score (mHHS), the Knee Injury and Osteoarthritis Outcome for Joint Replacement (KOOS Jr.), and the American Shoulder and Elbow Surgeons (ASES) Score as well as a custom satisfaction survey designed to elicit their subjective surgical preferences.
Results
Sixty-three patients (28 males, 44.4%) met the inclusion criteria and were available for analysis. The mean age at the time of total shoulder arthroplasty was 65.9 ± 9.0 years (range, 28 - 81). The mean follow-up after TSA was 6.62 ± 4.14 years (range, 2.04 - 19.05). The mean age at time of total hip arthroplasty was 65.4 ± 9.0 years (range, 27 - 79). The mean follow-up after THA was 7.01 ± 4.08 years (mean, 2.00 - 17.95). The mean age at the time of total knee arthroplasty was 65.5 ± 8.5 years (range, 35 - 82). The mean follow-up after TKA was 7.23 ± 3.90 years (2.00 - 19.23). The average postoperative functional outcome scores for the KOOS, Jr., ASES, and mHHS were 80.59, 82.37 and 83.73, respectively. The results of our custom survey demonstrated that the majority of patients (57.1%) reported that all three surgeries had an equally dramatic improvement on their quality of life followed by THA (17.5%), TSA (14.3%) and TKA (7.9%). With regards to greatest pain relief, the majority of patients again responded that all three surgeries equally improved their pain relief (39.7%) which was closely followed by THA (28.6%), TSA (19.0%), and TKA (11.1%). Notably, TKA was reported to be the most painful and difficult surgery in terms of recovery according to 55.6% and 49.2% of the respondents, respectively. Overall, the majority of patients reported that they would still recommend all three surgeries to friends and family (52.4%) and did not regret any of the surgeries (65.1%).
Conclusion
The results of our study indicate that elective multiple joint arthroplasty indicated for debilitating arthritis does in fact provide highly satisfactory subjective outcomes for the majority of patients. At the same time, our survey revealed that TKA may be uniquely challenging for patients in terms of recovery and thus closely monitored rehabilitation is warranted. Further investigation into the post-operative course and rehabilitation of these three major arthroplasties is required.
Orthopaedic Sports Medicine
Arthritis
Arthroplasty
Bones
Outcome Studies
Cartilage
Hip/Groin/Thigh
Knee
MRI
Osteoarthritis
Total Joint Replacement
X-ray

### 19891 Effect of age, gender, and bmi on incidence and satisfaction of a popeye deformity following biceps tenotomy or tenodesis: secondary analysis of a randomized clinical trial

Peter B MacDonald1
Sheila McRae1
Peter Lapner1
Treny M Sasyniuk1
Jason A Old1
Jamie Dubberley1
Fleur Verhulst2
Jarret M Woodmass
2Netherlands
Summary
Based on secondary analysis of a randomized clinical trial comparing biceps tenotomy versus tenodesis, biceps tenodesis may be favored in younger male patients to minimize risk of deformity and risk of dissatisfaction in the appearance of the arm following surgery.
Data
Background
The purpose of this study was to determine the incidence of Popeye deformity following biceps tenotomy versus tenodesis and evaluate risk factors and subjective and objective outcomes.
Methods
Data for this study were collected as part of a randomized clinical trial in which patients 18 years of age or older undergoing arthroscopic shoulder surgery for a long head of the biceps tendon lesion were allocated to undergo tenotomy or tenodesis. The primary outcome measure for this secondary analysis was rate of Popeye deformity at 24-months post-operative as determined by an evaluator blinded to group allocation. Those with a deformity indicated their satisfaction with the appearance of their arm on a 10 cm visual analog scale (VAS), rated their pain and cramping, and completed the American Shoulder and Elbow Score (ASES) and Western Ontario Rotator Cuff score (WORC). Isometric elbow flexion and supination strength were also measured. Cohen’s kappa was calculated to measure interrater reliability between patient and evaluator on the presence of a deformity. Logistic regression was performed to identify predictors of presence/absence of a Popeye deformity.
Results
One hundred and fourteen patients were randomly assigned to two groups of which 42 to the tenodesis group and 45 to the tenotomy group completed a 24-month follow-up. Based on clinical assessment, the odds of a Popeye in the tenotomy group were 4.3 times greater than in the tenodesis group (p=0.018) with incidence of 33% (15/45) and 9.5% (4/42), respectively. Surgical technique was the only significant predictor of perceived deformity with male gender trending towards significance (OR = 7.33, 95% CI 0.867–61.906, p=0.067). Mean (SD) satisfaction score of those with a deformity regarding appearance of their arm was 7.3 (2.6). Increasing satisfaction was correlated with increasing age (r=0.640; p=0.025) but there was no association with gender (r=-0.155; p=0.527) or BMI (r=-0.221, p=0.057). Differences in subjective outcomes were dependent on whether the Popeye was clinician- or self-assessed.
Conclusion
The odds of developing a perceived Popeye deformity was 4.3 higher after tenotomy compared to tenodesis based on clinician assessment. Male gender was trending towards being predictive of having a deformity. Younger patients were significantly less satisfied with a deformity despite no difference in functional outcomes at 24 months. Thus, biceps tenodesis may be favored in younger male patients to minimize the risk of Popeye and the risk of dissatisfaction in the appearance of their arm following surgery.
Elbow/Wrist/Hand
Arthroscopy
Muscle
Flexor Elbow Muscle
Physical Examination

### 20009 Relation between sleep position and rotator cuff tears

David P Richards
Daniel Miller
David MacDonald
Stephen D Miller
Quinn F Stewart
1USA
Summary
There is a significant relationship between side sleeping and rotator cuff tears.
Data
Purpose
To determine whether sleep position was related to rotator cuff pathology (partial thickness or full thickness rotator cuff tears). Type of Study: Retrospective review.
Methods
A consecutive series of patients that met the inclusion/exclusion criteria (n=58) were in seen in clinic between July 2019 and December 2019. All of these individuals had a significant partial thickness (> 50%) or full thickness rotator cuff tear determined by either ultrasound, MRI or both. All patients in this series either had an insidious onset of shoulder pain or their symptoms were related to the basic wear and tear of daily activities. Traumatic rotator cuff tears (those associated with a significant traumatic event such as shoulder instability, motor vehicle accidents, sports related injuries, etc …) were excluded. Previous shoulder surgery, recurrent rotator cuff tears and Worker’s Compensation cases were also excluded from this series. As part of the history taking process, the patients were asked what was their preferred sleeping position – side sleeper, back sleeper or stomach sleeper. A Chi-square test was conducted to determine the relationship between rotator cuff pathology and sleep position.
Results
Of the 58 subjects, 52 of the patients were side sleepers, 4 were stomach sleepers, 1 was a back sleeper and 1 preferred all 3 positions. Statistical analysis, utilizing the Chi-square test (p < .0001), demonstrated that rotator cuff tears were most often seen in side sleepers.
Conclusion
These results demonstrate a significant relationship between rotator cuff pathology and side sleepers.
Shoulder
Glenohumeral
Tears
Infraespinatus Tendon Injury
MRI
Outcome Studies
Preventative Sports Medicine
Rehabilition/Physical Therapy
Subescapular Tendon Injury
Supraespinoatus Tendon Injury
Tendon
Ultrasound

### 20058 Predictive signs of peripheral rim instability with magnetic resonance imaging in no-shift-type complete discoid lateral meniscus

Yusuke Hashimoto
Kazuya Nishino
Shinya Yamasaki
Yohei Nishida
Hiroaki Nakamura
Japan
Summary
A linear fluid signal at the anterior meniscus and anterior parameniscal soft-tissue edema were important signs of anterior peripheral rim instability, whereas bulging of the margin had high specificity but low sensitivity in detecting posterior peripheral rim instability on routine MRI of no-shift-type CDLM.
Data
Purpose
To investigate the associations between the preoperative MRI ?ndings suggestive of meniscal instability and the intraoperative ?nding of peripheral rim instability (PRI) in patients with no-shift-type complete discoid lateral meniscus (CDLM).
Methods
The records of 47 patients diagnosed with no-shift-type CDLM who underwent arthroscopic surgery were reviewed. We evaluated MRI findings of increased intrameniscal signal, anterior parameniscal soft-tissue edema, linear fluid signal at the anterior meniscal margin, bulging of the meniscal margin, absence of popliteomeniscal fascicles, hiatus widening on routine MRI. The positive predictive value (PPV), sensitivity, and specificity of these findings in predicting PRI were calculated; PRI was further investigated according to anterior and posterior location.
Results
Linear fluid signal at the anterior meniscal margin and bulging had high PPV, specificity (P=.001 and =.003, respectively) for overall of PRI. The presence of either anterior parameniscal soft-tissue edema or linear fluid signal at the anterior meniscal margin predicted anterior PRI with high PPV, sensitivity, and specificity. BEither bulging of the meniscal margin (P=.014) had high specificity but low PPV and sensitivity in predicting posterior PRI.
Conclusions
A linear fluid signal at the anterior meniscus and anterior parameniscal soft-tissue edema were important signs of anterior PRI, whereas bulging of the margin had high specificity but low sensitivity in detecting posterior PRI on routine MRI of no-shift-type CDLM.
Knee
Arthroscopy
Instability
Meniscus
Lateral
MRI
Outcome Studies

### 20138 Second-look arthroscopic evaluation and clinical outcomes after anatomical double-bundle anterior cruciate ligament reconstruction with generalized joint laxity or hyperextended knee

Yasunari Oniki
Taiki Murakami
Eiichi Nakamura
Japan
Summary
Generalized joint laxity and/or hyperextended knee (GJL and/or HK) affect ligamentization of the grafts and clinical outcomes after anatomic double-bundle ACL reconstruction. GJL and/or HK was placed in L group, while the other group was placed in N group, There was no significant difference between the two groups in AMB, however it was significantly poorer ligamentization in PLB in L group
Data
Purpose There are many factors—such as the surgical techniques used, rehabilitation protocol, and structural and physiologic characteristics of the patients—that contribute to success after anterior cruciate ligament (ACL) reconstruction. Recent studies have suggested generalized joint laxity (GJL) and/or hyperextended knees (HK) as risk factors for graft failure after ACL reconstruction. The aim of this study was to investigate whether GJL and/or HK affect ligamentization of the grafts and clinical outcomes after anatomic double-bundle (AD) ACL reconstruction.
Materials and Methods
One hundred twenty-six patients (mean age 20.6 ± 9.3 years) underwent ADACL reconstruction using semitendinosus tendon autografts. All operations were performed by one experienced surgeon. These patients consented to remove the post screw that fixed the grafts onto the tibia and to a second-look arthroscopic examination. The mean follow-up period after ACL reconstruction was 14.8 ± 3.6 months. Patients were divided into two groups. One patient group that had GJL and/or HK was placed in the laxity group (L group, n = 35), while the other group was placed in the normal group (N group, n = 91). The focus of the second-look arthroscopy was on graft thickness, apparent tension, and synovium coverage of the anteromedial bundle (AMB) and the posterolateral bundle (PLB) graft. Each bundle was evaluated as excellent, fair, or poor according to Hokkaido university classification. Functional evaluations involved instrument-measured side-to-side difference of anterior laxity (KS), peak isokinetic (60°/s) and isometric (80° of flexion) torque of the quadriceps and hamstrings, and one-leg hop test and heel-height difference (HHD). Subjective evaluations included the International Knee Documentation Committee (IKDC) subjective score and Lysholm score. Results The second-look arthroscopic evaluation of the AMB graft revealed no significant difference between each group (P = 0.26). However, the PLB graft showed an excellent rating in 62.9%, a fair in 25.7%, and a poor in 11.4% of the L group; it also showed an excellent rating in 82.4%, a fair in 17.6%, and a poor in 0% of the N group. The L group (P < 0.01) showed statistically significant results. There was no significant difference between the two groups in KS (P = 0.74), mean peak isokinetic torque (quadriceps: P = 0.56, hamstrings: P = 0.44), isometric torque (quadriceps: P = 0.80, hamstrings: P = 0.52) torque, HHD (P = 0.49), one-leg hop test (P = 0.29), the IKDC subjective score (P = 0.31) or Lysholm score (P = 0.48).
Conclusion
Our study showed poor ligamentization of the PLB after ADACL reconstruction due to GJL and/or HK. In the case with GJL and/or HK, rehabilitation management and the selection of surgical procedure may lead to more success graft ligamantization.
Knee
ACL
Double Bundle
Instability
Ligaments
Arthroscopy
Autograft
Outcome Studies
Physical Examination

### 20083 Primary interposition dermal allograft cuff reconstruction is superior to revision after failed cuff repair: a clinical and radiographic analysis

Ivan Wong
Nedal Alkhatib
Sara Sparavalo
Jie Ma
Summary
The results of our study demonstrate that arthroscopic bridging reconstruction results in improved patient outcomes in both the primary and revision setting with low re-tear rates.
Data
Background
Large or massive rotator cuff tears make up between 10–40% of all rotator cuff tears, yet there is no agreement on the best treatment. Previous studies have shown that acellular human dermal allograft (AHDA) can be used for bridging reconstruction with positive patient outcomes. The use of this surgical technique has not been studied in the primary or revision surgical setting. OBJECTIVE: To compare the clinical and radiographic outcomes of patients who received primary or revision arthroscopic bridging reconstruction.
Methods
This study is a retrospective review of a sequential series of patients who underwent arthroscopic bridging reconstruction (ABR) using AHDA by the primary author (IW). A total of 130 patients underwent ABR between 2010 and 2018. The inclusion criteria were patients with completed Western Ontario Rotator Cuff (WORC) questionnaire, Disabilities of the Arm, Shoulder, and Hand (DASH) score, or both pre-operatively and at multiple post-operative timepoints. Patients with missing WORC scores were excluded from the study. Eighty-three patients were included following chart review. Patients with available post-operative MRIs were also used for radiological assessment by an independent MSK-trained radiologist. Post-operative MRIs were reviewed to assess for graft integrity and changes to rotator cuff muscle atrophy (using the Warner classification) and fatty degeneration (using the Goutallier classification).
Results
There were 46 patients who received primary ABR and 37 who received revision ABR. Forty-eight patients had a post-operative MRI available for review (Primary: 25; Revision: 23). The demographics are summarized in Table 1. Both groups showed a significant improvement in WORC score post-operatively (p<0.001). Primary ABR resulted in higher post-operative WORC scores as compared to revision ABR (p=0.015; Figure 1). The incidence of complete re-tears in the primary group was 8% and 17.4% in the revision group. More than 35% of patients in the primary group showed improvement in fatty infiltration of the infraspinatus and supraspinatus muscles. There was a higher progression in muscle atrophy in the revision group as compared to the primary group (74% and 30%, respectively).
Conclusion
Arthroscopic primary arthroscopic bridging reconstruction for large/massive rotator cuff tears using acellular human dermal allograft had better improvement in their WORC scores compared to revision group at the final follow-up. Although the revision group had improved at the two-year follow-up, these changes in WORC score were not sustained at the final follow-up while the improvements were maintained for the primary group. The primary group had a smaller re-tear rate, better fatty infiltration and muscle atrophy as compared to the revision group. This suggests that primary bridging reconstruction provides better outcomes than a revision surgery.
Shoulder
Allograft
Tears
Arthroscopy
MRI
Repair/Reconstruction
X-ray

### 20104 Biomechanical comparison of a novel, multi-planar perpendicular whipstitch with the krackow stitch and standard whipstitch

Stefano Muscatelli
Kempland C Walley
Conor S Daly-Seiler
Joseph A Greenstein
Aaron David Sciascia
David P Patterson
Michael T Freehill
USA
Summary
The Krackow stitch is the superior technique for maximizing strength, while minimizing suture pull through, construct elongation, or graft compression.
Data
Introduction
Soft tissue repair and reconstruction commonly utilize the Krackow stitch and commercially designed whipstitch techniques, and both have been biomechanically evaluated. Perpendicular multi-planar fixation may improve the biomechanical properties compared to the commonly used techniques, as has been demonstrated with fracture fixation. The purpose of this study was to compare the elongation, yield load, ultimate failure, stiffness, and mode of failure of the traditional Krackow stitch, whipstitch, and a multi-planar perpendicular whipstitch. The hypothesis was that the multi-planar technique would demonstrate superior biomechanical properties over the standard techniques.
Materials and Methods
Thirty tibialis anterior cadaveric tendons were randomly assigned into 3 groups of 10. Three suturing techniques: the Krackow stitch (KS), standard commercial non-locking whipstitch (WS), and a novel, multi-planar perpendicular whipstitch (MP) were performed. The MP stitch was performed with orthogonal throws starting right to left, front to back, left to right, and back to front. Each technique used 4 passes of Number 2 FiberWire spaced 5 mm apart and ending 10 mm from the end of the tendon. Tendons were secured to a custom clamp and the other end sutured. Tendons were pre-loaded to 5N, pre-tensioned to 50N at 100 mm/min for 3 cycles, returned to 5N for 1 minute, cycled from 5N to 100N at 200 mm/min for 100 cycles, and then loaded to failure at 20 mm/min. Elongation measurements were recorded after pre-tensioning and cycling, and recorded across the suture-tendon interface as well as from the base of the suture-tendon interface to markings on the suture limbs (total construct elongation). One-way analyses of variance were performed, with Bonferroni post hoc analysis when appropriate.
Results
There were no differences in cross-sectional area or stiffness among the 3 groups (p>.05). The ultimate load for WS (183.33±57.44N) was significantly less compared to both MP (270.76±39.36N) and KS (298.90±25.94N) (p=.001). All 3 techniques were noted to have a decrease in tendon length at the suture-tendon interface during testing, termed compression. There was significantly more compression at the suture-tendon interface for WS compared to KS (p=.006). There was significantly less total construct elongation for KS compared to WS and MP for total displacement measured from pre-tensioning to the end of cycling (p<.001).
Conclusion
Based on these results, the Krackow stitch is the superior technique for maximizing strength, while minimizing suture pull through, construct elongation, or graft compression. If using the whipstitch for ease of use, the multi-planar perpendicular technique offers improved biomechanical properties over the standard whipstitch technique.
Orthopaedic Sports Medicine
Biomechanics
Sutures/Knots/Anchors
Tears
Acromio Clavicular
Ankle/Foot/Calf
Autograft
Capsuloligamentous Complex
Elbow/Wrist/Hand
Gastrocnemius Tendon Injury
Hamstrings Tendon Injury
Hip/Groin/Thigh
Knee
Patella Tendon Injury
Repair/Reconstruction
Rupture Tendon
Shoulder
Sterno-Clavicular
Tendon

### 19904 Comparison of pull-out strength following ligamentum teres reconstruction in the hip: peek corkscrew suture anchor versus cortical button fixation: a cadaveric study

Ajay C Lall
Hari Krishna Ankem
Samantha Diulus
Benjamin G Domb
USA
Summary
This cadaveric study highlighted the differences in pullout strength between two methods of graft fixation over the acetabular fossa that are commonly utilized in LT reconstruction.
Data
Background
In recent years, the role of the ligamentum teres (LT) in hip stability has been further explored. Consequently, the consequences of LT tears have also become better understood. LT reconstruction is an appropriate alternative in select cases of full-thickness tears. The technical variations in LT reconstruction fixation at the acetabular fossa are critical to achieve best functional results.
Purpose
The purpose of this study is to compare the pull-out strength of the PEEK corkscrew suture anchor to that of the cortical button fixation for ligamentum teres reconstruction in the hip.
Study design
Methods
In eight hip joint specimens, the acetabular socket was prepared after the native ligamentum teres was transected and the femoral head was removed. The pulvinar was excised, to allow for optimal visualization of the cotyloid fossa for placement of the button or anchor fixation device. Eight separate tibialis anterior grafts were then prepared by suturing a running-locking #2 FiberWire (Arthrex, Naples, FL) on each tail of the graft. Specimens were then mounted on a custom jig within a mechanical test frame (MTS Systems, Eden Prairie, MN) to allow for in-line pull of the graft-fixation construct, eliminating any angular or torsional torque. Four specimens were prepared with a suture-button (Arthrex, Naples FL), and the remaining four specimens were prepared with a 3.0-mm knotless, polyether ether ketone (PEEK) Corkscrew anchor (Arthrex, Naples FL). Following the preload, each specimen was loaded to failure at 0.5 mm/s. Stiffness and ultimate pullout force were measured for each specimen construct. Groups were compared statistically using an unpaired two-tailed Student’s t-test, with statistical significance set at p = 0.05.
Results
The suture button type fixation has greater mean pullout strength and required higher load to failure compared to the PEEK corkscrew anchor fixation method (346.0 ± 206.5 N vs. 195.9 ± 50.0 N). There was no significant difference in mean stiffness between the two methods of fixation (21.9 ± 5.4 vs 26.5 ± 5.8 N/mm). Discussion: This cadaveric study highlighted the differences in pullout strength between two methods of graft fixation that are commonly utilized in LT reconstruction. The suture button type fixation demonstrated greater pullout strength and required a higher load to reach failure compared to the PEEK corkscrew anchor fixation. To our knowledge, this is the first study comparing the different methods of LT reconstruction graft fixation on the acetabular side.
Conclusion
This cadaveric study highlighted the differences in pullout strength between two methods of graft fixation over the acetabular fossa that are commonly utilized in LT reconstruction. The method of suture button type fixation demonstrated better pullout strength and required higher load to failure compared to the PEEK corkscrew anchor fixation. To our knowledge, this is the first study comparing the different methods of LT reconstruction graft fixation on the acetabular side. We strongly believe that the results of this study can guide surgical decision making when selecting a fixation method for the LT graft during reconstruction.
Hip/Groin/Thigh
Labrum
Sutures/Knots/Anchors
Biomechanics
Impingement

### 20279 Clinical outcomes and complications of percutaneous achilles repair system versus isolated endoscopic flexor hallucis longus tendon transfer in the management of acute achilles tendon ruptures. A retrospective case series report with a minimum of 30 month

Nasef Mohamed N Abdelatif
Jorge Pablo Batista
1Egypt
2Argentina
Summary
The current study demonstrated satisfactory and almost equally comparable results with minimal complications in patients with acute achilles ruptures when treated by both methods.
Data
Background
The definitive management for Acute Achilles tendon ruptures (AATR) is yet to reach a final consensus. Both percutaneous and endoscopically assisted methods have been reported to produce good results in the surgical management of this injury. The aim of this study was to compare the clinical results between a percutaneous method and a recently described isolated endoscopically assisted Flexor hallucis longus (FHL) transfer method as surgical means of management in patients with acute Achilles tendon ruptures at a minimum followup period of thirty months.
Methods
One hundred and seventeen patients with an average age of 36.25 years were primarily included in the current study. These were divided into two groups: patients who underwent percutaneous repair using PARS? instrumentation system (PARS Group), and another group who underwent isolated endoscopic FHL transfer (FHL transfer Group) for treatment of AATR. The followup period of both study groups was for a mean of 42.54 months. Overall, three patients were lost in followup. Ultimately the PARS group consisted of 59 patients and the FHL transfer group of 58 patients. There were no statistical differences in demographics between both these study groups. Both groups received the same postoperative rehabilitation protocol. Both groups were clinically evaluated using AOFAS Ankle-hindfoot score, ATRS, and ATRA measures. In addition, ankle plantarflexion power, FHL dynamometry and Tegner activity levels were also documented for all patients. Return to previous levels of activities was also documented for all included cases.
Results
At 30 months postoperatively, ATRS, AOFAS, ATRA, ankle plantarflexion strength, and Tegner activity scores showed no statistical significance across both study groups. Overall complications were reported in 6 patients in the FHL group (10.3%) and in 8 patients in the PARS group (13.6%). MRI performed at a minimum of thirty months postoperative showed a homogenous continuous achilles tendon signal for 43 patients, and heterogenous signal intensity in 13 patients (23.21%). Ultimately, 54 patients and 53 patients returned to their same level of activity in the FHL (93.1%) and PARS groups (89.8%) respectively. No patients reported any great toe complaints or symptomatic deficits of flexion strength. No major neurovascular or skin complications were encountered.
Conclusion
The current study demonstrated satisfactory and comparable results with minimal complications when comparing the utilization of isolated endoscopic FHL tendon transfer or percutaneous PARS? achilles tendon repairs in the surgical management of acute Achilles tendon ruptures.
Ankle/Foot/Calf
Repair/Reconstruction
Tears
Tendon
Achilles Tendon Injury
Endoscopy
Evidence Based Medicine
MRI
Outcome Studies
Physical Examination
Professional Athletes/Olympians
Rupture Tendon
Sport Specific Population
Sutures/Knots/Anchors
Trauma
Ultrasound
X-ray

### 20069 Preoperative meniscal extrusion predicts unsatisfactory clinical outcomes and progression of osteoarthritis after isolated partial medial meniscectomy: a five-year follow-up study

João V Novaretti
Diego C Astur
Elton Luiz Batista Cavalcante
Camila Cohen Kaleka
Joicemar T Amaro
Moises Cohen
Brazil
Summary
Patients with preoperative meniscal extrusion of 2.2 mm or greater had unsatisfactory clinical outcomes and progression of osteoarthritis after isolated partial medial meniscectomy at a minimum of five years follow-up. Higher BMI and horizontal and root tears were associated with greater preoperative meniscal extrusion.
Data
The objective of this study was to examine the association between preoperative meniscal extrusion of patients undergoing partial medial meniscectomy with clinical outcomes and progression of osteoarthritis and to determine the extent of meniscal extrusion associated with unsatisfactory clinical outcomes and progression of osteoarthritis. Ninety-five patients who underwent partial medial meniscectomy with a minimum follow-up of five years were retrospectively reviewed. Preoperative meniscal extrusion was evaluated with MRI. Patients were assessed preoperatively and postoperatively with Lysholm and IKDC subjective scores for clinical outcomes and with IKDC radiographic scale for osteoarthritis. An ANOVA was used to analyze the variations in meniscal extrusion and the clinical and radiological outcomes. A regression analysis was performed to identify factors that affect preoperative medial meniscus extrusion and that influence results after partial meniscectomy. An optimal cutoff value for meniscal extrusion associated with unsatisfactory clinical outcomes and progression of osteoarthritis was established. Significance was set at P<.05. The mean ± SD preoperative and postoperative Lysholm scores were 59.6 ± 15.5 vs. 83.8 ± 13.1 (P < .001) and the mean preoperative and postoperative IKDC subjective scores were 59.4 ± 16.8 vs. 82.0 ± 15.8 (P < .001). Meniscal extrusion greater than 2.2 mm (sensitivity, 84%; specificity, 81%) and 2.8 mm (sensitivity, 73%; specificity, 85%) was associated with unsatisfactory (poor/fair) Lysholm and IKDC subjective scores, respectively. The progression of osteoarthritis, characterized as a change of at least one category on the IKDC radiographic scale, occurred when meniscal extrusion was greater than 2.2 mm (sensitivity, 63%; specificity, 75%). Patients with higher BMI had significantly greater meniscal extrusion that patients with normal BMI (P < .001). The medial meniscus was more extruded in patients with horizontal and root tears. In conclusion, patients with preoperative meniscal extrusion of 2.2 mm or greater had unsatisfactory clinical outcomes and progression of osteoarthritis after partial medial meniscectomy at a minimum of five years follow-up. Higher BMI and horizontal and root tears were associated with greater preoperative meniscal extrusion.
Knee
Arthroscopy
Meniscus
Osteoarthritis
Evidence Based Medicine
Medial
MRI

### 20086 Management of acute knee dislocations: a global survey of orthopaedic surgeons’ strategies

Santa-Marie Venter1
Roopam Dey1
Vikas Khanduja2
Richard P von Bormann1
Michael Held1
1South Africa
2UK
Summary
This questionnaire based study shows that treatment of knee dislocations varied significantly based on the economic status of the country.
Data
Purpose
The aim of this study was to compare the management approach of acute knee dislocations (AKDs) by orthopaedic surgeons from nations with different economic status.
Methods
A survey sent to members of the Societe Internationale de Chirurgie Orthopedique et de Traumatologie (SICOT) compared different management strategies for acute multiligament knee injuries (aMLKIs). These were compared after categorising surgeons into developed economic nations (DEN) and emerging markets and developing nations (EMDN) based on the gross domestic product (GDP) per capita.
Results
138 orthopaedic surgeons from 47 countries participated in this study. DEN surgeons had more years of experience and were older (p<0.05). Surgeons from EMDN preferred conservative management and delayed reconstruction with autograft (p<0.05) if surgery was necessary. Surgeons from DEN favoured early, single stage arthroscopic ligament reconstruction. Significantly more EMDN surgeons preferred clinical examination (p<0.05) and duplex doppler scanning (p<0.05) compared to DEN surgeons. More surgeons from EMDN did not have access to a physiotherapist for their patients.
Conclusions
Treatment of aMLKIs varied significantly based on the economic status of the country. In EMDN, aMLKIs are often treated conservatively, ligament surgery is often delayed and staged, alternative vascular assessment methods are more commonly used, and access to physiotherapy is challenging. This calls for adjusted guidelines when treating patients in areas of low resource setting.
Knee
Dislocation
Ligaments
PCL
Repair/Reconstruction
Allograft
Arthroscopy
Autograft
Posterolateral

### 19858 Introducing the impingement index: a study of the combined effect of alpha angle and femoral version on outcomes after hip arthroscopy for fai

Danyal H Nawabi
Ronak M Patel
Ryan S Selley
Matthew S Dooley
Stephanie S Buza
Anil S Ranawat
Bryan T Kelly
USA
Summary
Patients with significant femoral retroversion and large cam lesions may experience less overall improvement compared with normal or increased version.
Data
Introduction
Many studies within the recent literature have sought to identify the effect of femoral version and other morphologic characteristics on outcomes after primary hip arthroscopy for femoral acetabular impingement (FAI). In addition to femoral version and combined version, our group has recently begun to use the ‘Impingement Index’ to stratify patients undergoing this procedure. We define the impingement index as the alpha angle minus the femoral version.
Purpose
The purpose of the current study is to determine the impact of femoral version, combined version and impingement index on patient reported outcomes after primary hip arthroscopy for FAI.
Methods
A retrospective chart review of prospectively collected data was conducted from 2010–2016 to identify consecutive patients who underwent primary hip arthroscopy for treatment of FAI. Inclusion criteria are pre-operative CT scan, <Tonnis grade 1 degenerative changes, and minimum 1-year follow-up. Demographics, CT measurements (femoral version, acetabular version, alpha angle, and lateral center edge angle), and patient-reported outcomes scores (mHHS, HOS ADL, HOS Sport, QOL), were evaluated. McKibbin and impingement indices were calculated from CT measurements.
Results
A total of 456 hips (200 males, 256 females) met inclusion criteria. The mean age at time of surgery was 28.2 years (±10). Average follow-up was 2.6 years (range 23–59 months). The cohort experienced clinical improvement (p<0.001) in all patient-reported outcome measures. The mean improvement was 21.4 points for mHHS, 17.4 for HOS ADL, 29.5 for HOS Sport, and 34.3 for QOL. There was no significant difference in outcomes scores when stratified by femoral version (<5, 5–20, >20), including at the extremes of femoral version (<-5, >30). There was also no significant difference in outcomes scores when patients were stratified by Mckibbin Index (<25, 25–40, >40). The net change in mean HOS Sport for impingement index >75 was also significantly lower than any other category (14.5 (>75) vs. 28.1 (45–75) vs. 25.7 (<45).
Conclusion
Clinically significant improvements can be expected for all femoral version values when a thoughtful algorithm is employed for indicating patients for hip arthroscopy with version abnormalities. However, patients with significant femoral retroversion and large cam lesions may experience less overall improvement compared to patients with normal or increased version. The impingement index may be a valuable tool for predicting outcomes of primary hip arthroscopy for FAI.
Hip/Groin/Thigh
Arthroscopy
Bones
Impingement
CT-Scan
Labrum
Labrum Tears
Labrum Treatment
MRI
Outcome Studies
Sport Specific Population
X-ray

### 20093 Evaluating the efficacy of micro-fragmented adipose tissue and intra-articular corticosteroid injections for symptomatic knee osteoarthritis: a randomized, placebo controlled study. Preliminary results

Dustin Richter
Joshua Harrison
Lauren Faber
Anil K Shetty
Yiliang Zhu
Carina Suki Pierce PA-C
Robert C Schenck
USA
Summary
For the treatment of symptomatic knee osteoarthritis, preliminary data show that the microfragmented adipose tissue injection group demonstrated consistently the largest improvement in outcome scores at 6–12 month follow-up compared with the placebo and corticosteroid groups.
Data
Objectives Knee osteoarthritis (OA) is a debilitating joint disorder affecting tens of millions of people worldwide. Nonoperative treatment options have variable efficacy and none stop or reverse the progression of OA. Furthermore, there is a lack of literature supporting the efficacy of intra-articular corticosteroids, one of the most common treatment options. The purpose of this study is to evaluate pain relief and functional improvement after knee OA treatment with a novel therapeutic intervention, microfragmented adipose tissue, in comparison to a saline placebo and gold-standard corticosteroid injections.
Methods
Patients with radiographic knee OA, a minimum pain score of 3 on the visual analog scale (VAS), and no prior knee injection were eligible for inclusion. Patients were randomized to one of three treatment groups: microfragmented adipose tissue (MFAT), corticosteroid (CS), or saline placebo (P) injection. Both the practitioner and patient were blinded to the injection in the CS and P groups. A sham liposuction procedure was not performed. For the MFAT group, both an orthopaedic surgeon and plastic surgeon performed the lipoaspiration portion together under local anesthesia. The VAS pain scale, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Knee Injury and Osteoarthritis Outcome Score scale (KOOS) were recorded pre-procedure and at specified time points post-procedure up to one year.
Results
A total of 62 patients have been enrolled (92% follow-up), with a study goal of 75 total patients to achieve power. Patients were randomized to: MFAT = 22, CS = 21, P = 19. A preliminary analysis of these 62 patients was completed to compare post-procedure outcomes to pre-procedure pain and functionality. The WOMAC score improved in the MFAT group by a mean of 30 points at 1 year follow-up, compared to 10 in the CS and 11 in the P groups (p = 0.01). The KOOS pain score improved in the MFAT group by a mean 32 points at 1 year follow-up, compared to 8 in the CS and 11 in the P groups (p=0.03). VAS scores improved across all groups with average changes: MFAT 3.4, CS 1.5, P 1.4 (p = 0.14). When a linear mixed effects model was used to quantify changes in outcomes over the 1 year post-procedure period, the MFAT group demonstrated a consistently positive improvement across all five outcomes measures, whereas no consistent trend was noted in the P group and a negative trend was noted in the CS group after the initial 2 week improvement. Patients with more severe radiographic knee OA had poorer outcome scores in all groups. No complications were noted in any of the study patients with the exception of mild expected donor site morbidity of minor pain and ecchymosis in the MFAT group.
Conclusions
Nonoperative knee OA treatment options are limited with variable efficacy. It is critical to evaluate patient outcomes rigorously prior to instituting novel procedures or treatments. Preliminary data show the microfragmented adipose tissue injection group demonstrated consistently the largest improvement in outcome scores at 6–12 month follow-up compared with the placebo and corticosteroid groups.
Knee
Arthritis
Biologics
Cartilage
Osteoarthritis
Outcome Studies
Stem Cell Therapy
X-ray

### 20194 The effect of lateral extra-articular tenodesis on medial and lateral menisci loading in response to simulated tests of the pivot shift and anterior laxity

Niv Marom1
Danyal H Nawabi2
Hamid Jahandar2
Thomas Fraychineaud2
Herve Ouanezar3
Ronak M Patel2
Carl W Imhauser2
Thomas L Wickiewicz2
Andrew D Pearle2
1Israel
2USA
3United Arab Emirates
Summary
ACLR in isolation is an effective strategy to normalize the increased loads on both menisci with ACL deficiency during pivoting and anterior laxity tests. LET augmentation to ACLR may increase lateral meniscal load in flexion, which may affect outcomes in cases of concomitant lateral meniscal pathology
Data
Background
The biomechanical impact of lateral extra-articular tenodesis (LET) performed in conjunction with anterior cruciate ligament reconstruction (ACLR) on loads carried by the knee menisci is not clear. Alterations in menisci loading may affect meniscal integrity and healing potential when injured.
Purpose
To quantify forces carried by the lateral and medial menisci in response to simulated tests of the pivot shift and anterior laxity in various knee conditions including the intact ACL knee, sectioned ACL knee, ACLR knee and ACLR augmented with LET.
Methods
34.8±11.7; 4 male) were mounted to a robotic manipulator. The robot simulated two types of pivoting maneuvers and tests of anterior laxity; namely, the Lachman and anterior drawer. Each knee was assessed in the following states: ACL intact, ACL sectioned, ACL reconstructed (using a bone-patellar tendon-bone autograft), and finally, after performing LET (a modified Lemaire technique, after sectioning the anterolateral ligament (ALL) and Kaplan fibers). Resultant forces carried by the medial and lateral menisci at the peak applied loads were determined via superposition.
Results
Compared to the intact knee, sectioning the ACL increased lateral meniscus force by up to 57% (40 N, p=0.014) with applied pivoting loads. This increase was observed only at 30° of flexion. Augmenting ACLR with LET increased lateral meniscus force by 43% (31 N, p=0.041) at 30° of flexion. Compared to the intact knee, sectioning the ACL increased medial meniscus force by up to 102% (73.5N, p<0.001) and 18% (19 N, p=0.01) during the simulated Lachman and anterior drawer, respectively. Augmenting ACLR with LET did not result in a statistically significant change in medial meniscus force during the tests of anterior laxity. For all conditions tested and for both menisci, no statistical significant difference in force was detected between the intact and ACL reconstructed knee.
Conclusion
Our data support ACLR in isolation as an effective strategy to normalize the increased loads on both menisci with ACL deficiency during pivoting and anterior laxity tests. LET augmentation to ACLR may increase lateral meniscal load in flexion, which may affect outcomes in cases of concomitant lateral meniscal pathology. These data can guide clinicians with additional implications of LET augmentation to ACLR and may suggest a more conservative post-surgical management early on in cases of combined ACLR+LET with lateral meniscus pathology.
Knee
ACL
Instability
Ligaments
Repair/Reconstruction
Anterolateral Ligament
Biomechanics
Lateral
Medial
Meniscus
Tears

### 20197 How do we evaluate return to sport after anterior cruciate ligament reconstruction? A systematic review of methodologies

Niv Marom1
William Xiang2
Isabel Wolfe2
Bridget Jivanelli2
Riley J Williams2
Robert G Marx2
1Israel
2USA
Summary
This review demonstrates high variability in defining, evaluating and reporting patterns of Return To Sport after ACL reconstruction and raises significant concerns regarding the reliability and validity of methods used to determine Return To Sport in ACL reconstruction literature
Data
Background
Return to sport (RTS) after ACL reconstruction (ACLR) has been recognized as an important outcome, which is associated with success of the surgery and has been increasingly reported on in recent years based on non-standardized evaluation methods.
Purpose
To assess the methods used to determine return to sport after ACLR in the published literature, report on variability of methods and evaluate their strength in establishing accurate RTS data. Study design: Systematic review of methodology.
Methods
Electronic databases (PubMed, Cochrane Library and Embase) were searched via a defined search strategy with no limits, to identify relevant studies from January 2008 to January 2020 for inclusion in the review. A priori defined eligibility criteria included studies specifically measuring and reporting on return to sport after ACLR with a clear methodology. Each included study was primarily assessed for the methodology used to determine return to sport and level of sport.
Results
145 studies were included. Among the excluded studies, 54 studies reported on RTS after ACLR, but were not included due to unclear RTS evaluation method used. Of the included studies, five studies (3%) were level of evidence 1 and sixty-six studies (46%) were level of evidence 4. Thirty-six studies (25%) reported on return to a specific sport and 109 studies (75%) reported on return to multiple sports or general sport. Fourteen studies (10%) reported on RTS in the pediatric population, twenty-five (17%) in the adult population and one hundred and six (73%) reported on a mixed-aged population. Five definition categories of successful general RTS, four definition categories of successful return to pre-injury level of sport and four categories of different methods used to determine RTS were established. The most common method used to evaluate RTS was a non-validated study specific questionnaire (61 studies, 42%), which was administered in various ways to the patients. Time of RTS assessment was variable and ranged between 6 months to 27 years post-surgery.
Conclusion
This review demonstrates high variability in defining, evaluating and reporting patterns of RTS following ACLR. The findings of this study raise concerns regarding the reliability and validity of methods used to evaluate RTS. Our findings highlight the challenges in interpreting and using RTS data reported in literature and should serve to caution clinicians to carefully evaluate the methods used in studies reporting on RTS after ACLR. Future research should focus on establishing standardized and validated methods for RTS evaluation.
Orthopaedic Sports Medicine
Instability
Outcome Studies
Repair/Reconstruction
ACL
Knee
Ligaments
Sport Specific Population

### 20037 Tranexamic acid has no effect on post-operative hemarthrosis or pain control following acl reconstruction using bone patella tendon bone autograft: a double-blinded randomized control trial

Jordan W Fried
David Bloom
Eoghan T Hurley
Samuel Baron
Kirk Anthony Campbell
Eric Jason Strauss
Laith M Jazrawi
Michael J Alaia
USA
Summary
TXA did not decrease the incidence of hemarthrosis in those undergoing ACLR.
Data
Purpose
The purpose of this double-blinded randomized controlled trial was to evaluate the use of intravenous (IV) tranexamic acid (TXA) in patients undergoing primary bone-patella tendon-bone (BTB) ACLR with regard to post-operative hemarthrosis, pain, opioid consumption, quadriceps atrophy and activation.
Methods
A controlled, randomized, double-blinded trial was conducted in 110 patients who underwent ACLR with BTB autograft. Patients were equally randomized to the control and experimental groups. The experimental group received two 1-gram boluses of IV TXA, one prior to tourniquet inflation and one prior to wound closure; the control group did not receive TXA. If a clinically significant hemarthrosis was evident, the knee was aspirated, and the volume of blood (ml) was recorded. Additionally, perioperative blood loss (ml); Visual Analog Scale (VAS) on postoperative days (POD) 1-7 and post-operative weeks (POW) 1, 6 and 12; postoperative opioid consumption POD 1-7; range of motion (ROM) and ability to straight leg raise (SLR) at POW 1, 6, 12; and pre and postoperative thigh circumference ratio (TCR).
Results
There was no significant difference in perioperative blood loss between the TXA and control groups (32.5ml v. 35.6ml, p=0.47). The TXA group had 23 knees aspirated; control group had 26 knees aspirated (p=0.56). No significant difference seen in postoperative hemarthrosis volume with IV TXA compared to those without (26.7ml v. 37.3ml, p=0.12). There was no significant difference in VAS score between the two groups (p=0.15), additionally, there was no difference in postoperative opioid consumption (p=0.33). There was no significant difference in ROM or ability to SLR, or post-operative TCR (p > 0.05 for all).
Conclusion
IV TXA in patients who undergo ACLR with BTB autograft does not significantly impact perioperative blood loss, postoperative hemarthrosis, or postoperative pain levels. Additionally, no significant differences were seen in early post-operative recovery regarding ROM or quadriceps reactivation.
Knee
ACL
Autograft
Instability
Ligaments

### 20039 Open subpectoral biceps tenodesis versus arthroscopic repair for slap tears in patients under 30

Eoghan T Hurley1
Christopher Angelo Colasanti2
Nathan A Lorentz2
Kirk Anthony Campbell2
Laith M Jazrawi2
Eric Jason Strauss2
Bogdan Matache3
Michael J Alaia2
1Ireland
2USA
Summary
Biceps tenodesis is a reliable alternative to arthroscopic repair, with a lower rate of revision surgery, and excellent patient reported outcomes.
Data
Purpose
The purpose of the current study is to compare the outcomes of BT to AR for SLAP tears in patients under the age of 30. Our hypothesis was that there would be no statistically significant difference in outcomes between the two procedures. STUDY DESIGN: Retrospective Comparative Study; Level of evidence III
Methods
A retrospective review of patients who underwent either isolated BT or AR for the diagnosis of a SLAP tear was performed. Patients with a follow-up duration of <24 months were excluded. The American Shoulder & Elbow Surgeons (ASES) score, Visual Analogue Scale (VAS), Subjective Shoulder Value (SSV), patient satisfaction, willingness to undergo surgery again, revisions, and return to play (RTP) were evaluated. A p value of <0.05 was considered to be statistically significant.
Results
Our study included 103 patients in total; 29 patients were treated with BT, and 74 were treated with AR. The mean age was 24.8 years, 79.4% were male, and the mean follow-up duration was 60 months. At final follow up, there was no difference between treatment groups in any of the functional outcome measures assessed (p > 0.05). Overall, there was no significant difference in the total rate of RTP (BT: 76.3%, AR: 85%; p = 0.53), timing of RTP (BT: 8.8 months, AR: 9.4 months; p = 0.61), and total rate of RTP among overhead athletes (BT: 84.2%, AR: 83.3%; p = 1). However, there was a significantly lower rate of revision surgery with BT (0%) as compared to AR (14.1%; p = 0.03).
Conclusion
The most important finding from this study was that in patients under the age of 30 with a symptomatic isolated SLAP tear, biceps tenodesis is a reliable alternative to arthroscopic repair, with a lower rate of revision surgery, and excellent patient reported outcomes. Furthermore, there was a high rate of RTP among athletes, with no difference in RTP metrics between the two groups, and no difference among overhead athletes.
Shoulder
Glenohumeral
Tears
Arthroscopy
Labrum

### 19950 Tranexamic acid has no effect on post-operative hemarthrosis or pain control following tibial tubercle osteotomy: a double-blinded randomized control trial

Anna Blaeser
Eoghan T Hurley
Jordan W Fried
Kirk Anthony Campbell
Laith M Jazrawi
Eric Jason Strauss
Michael J Alaia
USA
Summary
TXA did not decrease the incidence of haemarthrosis in those undergoing TTO.
Data
Background
Tranexamic acid (TXA) is an antifibrinolytic, commonly utilized in orthopedic procedures for the purpose of reducing perioperative bleeding and need for transfusion.
Purpose
To evaluate if IV TXA for tibial tubercle osteotomy (TTO) could reduce perioperative blood loss or postoperative intra-articular hemarthrosis without postoperative drains.
Methods
A double-blind randomized controlled trial was conducted in patients who underwent TTO. Forty patients were randomized equally to the control and experimental groups. The experimental group received two 1-gram boluses of IV TXA, one prior to tourniquet inflation and one prior to wound closure; the control group did not receive TXA. The following outcomes were documented: perioperative blood loss (cc), postoperative hemarthrosis (cc), Visual Analog Scale (VAS) on postoperative days (POD) 1-7 and postoperative visits (POV) 1-3, postoperative opioid consumption POD 1-7 (morphine mg equivalents), range of motion (ROM) and ability to straight leg raise (SLR) at POV 1-3, and pre- and post-operative thigh circumference ratio (TCR). Study Design: Randomized Controlled Trial.
Results
There was no significant difference found in perioperative blood loss between experimental and control groups (64.25cc v. 60cc, p=0.38). No statistical significance was observed in patient demographic characteristics. All patients were available at the first POV for hemarthrosis evaluation. There were 3 knees aspirated in each of the groups; no significant difference was found in postoperative hemarthrosis with use of IV TXA (3.3cc v. 14cc, p=0.09). Significantly reduced levels of pain were seen throughout the first postoperative week in both the experimental and control groups (p=0.022, p<0.0001), but no significant reduction in VAS score between the two groups (p=0.15). No significant difference was noted in post-operative opioid consumption by the end of the first week (120.21mg v. 120.58mg, p=0.5). No significant difference in ROM or ability to SLR at all three postoperative visits. No significant difference in pre- nor post-operative TCR (p=0.15, p=0.70).
Conclusion
In patients undergoing TTO, intravenous TXA does not significantly impact perioperative blood loss, postoperative hemarthrosis, or postoperative pain control. Additionally, IV TXA did not impact ROM, ability to SLR, or TCR following TTO.
Knee
Osteotomy
Patellofemoral

### 19988 Can talented youth soccer players who have undergone anterior cruciate ligament reconstruction reach the elite level?

Alexander Sandon
Tor Söderström
Andreas Stenling
Sweden
Summary
ACL reconstructive surgery in talented youth soccer players offers them the opportunity to become elite players as seniors and permits an activity level on a par with that of their uninjured peers.
Data
Background
Anterior cruciate ligament (ACL) ruptures are common in soccer players, and reconstructive surgery is often performed to restore knee stability and enable a return to play.
Purpose
To investigate whether an ACL reconstruction for talented youth soccer players affects their potential to become elite players at the senior level. Study Design: Cohort study; Level of evidence, 3.
Methods
All soccer players who participated in the Swedish National Elite Camp for 15-year-old players between 2005 and 2011 (N = 5285 players; 2631 boys and 2654 girls) were matched with the Swedish National Knee Ligament Registry to identify the players who had undergone ACL reconstruction. Information on player participation in Swedish league games and level of play was collected from the Swedish Football Association’s administrative data system. The players with an ACL reconstruction who were injured at the ages of 15 to 19 years were compared with the rest of the players who participated in the National Elite Camp to see whether an early ACL reconstruction affected whether they remained active as soccer players and their chance to play at the elite level as seniors.
Results
A total of 524 (9.9%) players had undergone an ACL reconstruction, and 292 (5.5%; 75 male and 217 female) had sustained their injury at age 15 to 19 years. During the follow-up period, 122 (23.3%) players underwent further ACL reconstruction: revision (11.5%; n = 60) or contralateral (11.8%; n = 62). Male and female soccer players undergoing an ACL reconstruction at age 15 to 19 years experienced no significant effect on being active or playing at the elite level in the season that they turned 21 years old. Of the youth players who underwent ACL reconstruction, 12% of the male players and 11.5% of the female players progressed to the elite level at the age of 21 years compared with 10.3% of the men and 11.1% of the women among the uninjured players.
Conclusion
ACL reconstructive surgery in talented youth soccer players offers them the opportunity to become elite players as seniors and permits an activity level on a par with that of their uninjured peers. However, almost 1 in 4 requires further ACL surgery, so the players’ future knee health should be considered when deciding on a return to play.
Orthopaedic Sports Medicine
Instability
Sport Specific Injuries
ACL
Epidemiology
Knee
Ligaments
Outcome Studies
Professional Athletes/Olympians
Repair/Reconstruction
Sport Specific Population

### 20161 Influence of stem cells application during surgery on the improvement of vertical jump in patients after achilles tendon rupture

Magdalena Syrek
Urszula E Zdanowicz
Robert Smigielski
Michal Staniszewski
Poland
Summary
Stem cells application in Achilles tendon reconstruction can accelerate rehabilitation programme’s progress resulting in better values of jump parameters after one year.
Data
This study was conducted to evaluate results of stem cells application during the Achilles tendon reconstruction. The evaluation was based on the measurements of vertical jump six months and one year after the surgery. The evaluated group included 60 patients (mean age: 37±5,1 years) who had undergone Achilles tendon reconstruction. Achilles tendon reconstruction procedures aimed at the restoration of the tendon’s three-bundle structure and anatomical rotation of its fibres stemming from the gastrocnemius and soleus muscles. Patients were randomly divided into two groups (30 persons each); one undergoing a standard surgical procedure (G1), in the second group (G2) the same procedure was extended by the direct application of autologous mesenchymal stem cells (MSC) harvested from the subject’s fat tissue. All patients started physiotherapy the next day postop and continued (tri-weekly) for about 6 months (avg. 6,1 months). All patients underwent a uniform rehabilitation protocol including concentric, eccentric and balance exercises. The objective evaluation was based on unilateral countermovement jumps (CMJ). Maximum Height (HVmax) and maximum Power (Pmax) was recorder on the force plate. Measurements were made six months after the surgery and repeated a year later to establish patients’ progress. The comparison of differences between the groups was performed with the U Mann-Whitney test. The normality of distribution was evaluated with the Shapiro-Wilk test. For both the test significance was set at p < 0.05. For the analysis of the test results, a statistical package by StatSoft, Inc. (2011) STATISTICA, v.10 was used. Testing performed 6 months postop has shown lower HVmax and Pmax in the operated limb compared to the healthy leg in both testing groups. After one year, statistically significant differences of both parameters were still visible in G1 group (p <0.05). In G2 group, only HVmax remained significantly lower. Analysis of the operated limb in both groups conducted one year after surgery in comparison to 6 months results, has shown significantly improved Pmax value in G2 group. The use of stem cells during the reconstruction of the Achilles tendon increased the maximum power during the vertical jump of the operated limb, indicating that the use of stem cells may improve the tendon function and the patient‘s faster return to pre-injury activity.
Ankle/Foot/Calf
Repair/Reconstruction
Tears
Tendon
Achilles Tendon Injury
Biomechanics
Preventative Sports Medicine
Rehabilition/Physical Therapy
Rupture Tendon
Sport Specific Injuries
Sport Specific Population
Stem Cell Therapy

### 20062 Autologous semitendinosus tendon graft as meniscal transplant – a pilot study

Pierre Rotzius
Karl Eriksson
Sweden
Summary
Autologous semitendinosus tendon could potentially be an option for meniscus substitution in selected cases.
Data
Introduction
Meniscectomy result in poor knee function and increased risk for osteoarthritis. Meniscal allograft transplantation is not widely used due to costs and availability. The semitendinosus tendon (ST) has the potential to remodel and revascularize in an intraarticular environment such as ACL reconstruction. The objective for this pilot study was to investigate whether the ST graft could function as a meniscal transplant.
Material and methods
The ST was doubled and sutured with running sutures and pull-out sutures in each end. Bone tunnels were used for root anchorage and the graft was sutured with all-inside, inside-out and outside-in technique. The pull-out sutures were fixed over a button. Partial weight bearing was allowed with limited range of motion in a brace for the first six weeks. Evaluation was assessed using clinical examination, radiology and patient reported outcome. Results A total of seven patients have been included between January 2018 and June 2020. Six medial transplants and one lateral transplant were performed. Mean age was 29 years. Four patients had completed the 12-month follow-up. Improvements were noted for IKDC Global Score (p=0.004), KOOS pain subscale (p=0.038) and Lysholm (p=0.005). MRI indicate that the transplant become more wedge-like with visible roots and minor protrusion. The results will be updated accordingly before the presentation.
Conclusion
Even though this is primarily a technical report the follow-up data indicate that the transplant survives and adapts in shape and capabilities to an original meniscus. There were no adverse events and the patients seem to improve in terms of pain and quality of life.
Knee
Meniscus
Transplantation
Autograft
Basic Science
Epidemiology
Lateral
Medial
Outcome Studies
Practice Management
Preventative Sports Medicine
Sport Specific Injuries
Tears

### 19780 Traumatic hip dislocations in the pediatric patient: injury patterns, need for axial imaging, outcomes, and selective hip arthroscopy

Samuel C Willimon
Anthony Egger
Crystal A Perkins
USA
Summary
Post-reduction advanced imaging following traumatic hip dislocations demonstrated posterior wall fractures in 78% and incarcerated fragments in 30%, and selective hip arthroscopy for the treatment of loose bodies and labral pathology was associated with excellent outcomes.
Data
Introduction
Traumatic hip dislocations are uncommon injuries in the pediatric population. Injury recognition and prompt closed reduction is standard of care. The purpose of this study is to describe injury patterns, treatment (including hip arthroscopy), and patient reported outcomes of traumatic hip dislocation in pediatric patients.
Methods
A retrospective review was performed of all patients less than 18 years of age treated for a traumatic hip dislocation between 2011–2017 at a single center. Chart and radiographic review were performed, and patients were contacted to obtain outcome scores, including the Harris hip score (HHS) and hip outcome score (HOS).
Results
Conclusions
Traumatic hip dislocations in the pediatric population occur most frequently as isolated orthopaedic injuries in association with posterior wall acetabular fractures. Incarcerated fragments occurred in 30% of the patients, yet were commonly not recognized on plain radiographs alone. Axial imaging, either MRI or CT, should be routinely obtained following reduction. Selective hip arthroscopy after traumatic hip dislocations is a viable less invasive method for treatment of incarcerated fragments and labral injury.
Hip/Groin/Thigh
Bones
Dislocation
Repair/Reconstruction
Arthroscopy
Capsuloligamentous Complex
CT-Scan
Labrum
Labrum Tears
Labrum Treatment
MRI
Osteonecrosis
Outcome Studies
Trauma
X-ray

### 19795 Osteochondral lesions of the talus: factors predictive of cartilage integrity

Crystal A Perkins
John Erickson
Kiery Braithwaite
Michael T Busch
Samuel C Willimon
USA
Summary
Physeal status, radiographic grade, MRI grade, and cartilage integrity on MRI are independent predictors of cartilage integrity at the time of ankle arthroscopy for patients with OLTs.
Data
Background
The integrity of articular cartilage in patients with osteochondral lesions of the talus (OLTs) guides treatment. The ability to predict cartilage integrity in OLTs, as previously published for OCD of the knee, would be beneficial. The purpose of this study is to evaluate the association of radiographic and MRI findings and articular cartilage integrity at the time of ankle arthroscopy for OLTs.
Methods
A single-institution retrospective review identified patients 19 years of age and younger with operative treatment of OLTs from 2010–2017. Demographics and intra-operative findings at the time of ankle arthroscopy were identified by chart review. Radiographs were assessed for physeal status, OLT location, and Berndt and Hardy grade. MRIs were reviewed for OLT size and location, modified Kramer grade, and cartilage status.
Results
53 patients with 54 OLTs and a mean age of 13.6 years (range 7–19 years) were included. OLTs were located in the posteromedial talus in 39 patients (72%). Physeal status was closed/closing in 32 patients (59%) and open in 22 patients (41%). On MRI, the cartilage was predicted to be disrupted in 40 patients (74%) and intact in 14 patients (26%). At the time of ankle arthroscopy, the cartilage was found to be disrupted in 38 OLTs (70%) and intact in 16 OLTs (30%). MRI classification of cartilage integrity was 95% sensitive and 75% specific for arthroscopic integrity, with 11% misclassification. In the 16 patients less than 13 years, MRI perfectly predicted arthroscopic cartilage integrity. In patients with open physes, MRI sensitivity was 92% and specificity 100%. In patients with closing/closed physes, MRI sensitivity was 89% and specificity 50%. Receiver operator curve characteristics of a model to predict arthroscopic cartilage integrity combining MRI cartilage integrity, physeal status, and radiographic grade has an AUC of 0.955.
Conclusions
Physeal status, radiographic grade, MRI grade, and cartilage integrity on MRI are independent predictors of cartilage integrity at the time of ankle arthroscopy for patients with OLTs. Overall, MRI has 95% sensitivity and 75% specificity for cartilage integrity at the time of arthroscopy, which improves to near 100% sensitivity and specificity in patients with open physes. A model combining MRI cartilage integrity, physeal status, and radiographic grade has the highest predictability of intra-operative cartilage integrity.
Ankle/Foot/Calf
Arthroscopy
Bones
Cartilage
MRI
Osteochondritis

### 20217 Does oral stain use affect rotator cuff healing or muscle fatty atrophy after rotator cuff repair?

Jan Herman Kuiper
Martyn Snow
UK
Summary
Statin do not have any effect on rotator cuff healing or fatty atrophy of cuff muscles after repair.
Data
Objectives: Statin use has been linked to structural and vascular changes in tendon and therefore there are concerns over a higher incidence of re-tear after repair. The objective of our study was to evaluate the effect of statins on rotator cuff healing following repair and also on the progression of fatty atrophy (Goutallier grade).
Methods
A cohort of 77 patients undergoing rotator cuff repair for isolated posterior/superior rotator cuff tear were prospectively evaluated. Pre-operative details such as demographic profile and statin use were collected. Patient reported outcome measure (PROM) scores including Constant score, American shoulder and elbow surgeons (ASES) score and Disability of arm, shoulder and hand (DASH) score were collected preoperatively and at one year. All the patients had MRI pre-operatively and at one year to quantify rotator cuff healing based on the Sugaya classification and Goutallier staging of fatty atrophy. All MRI’s were assessed by a blinded radiologist. Intra-operative details such as cuff tear size, method of repair (single row or double row), and concomitant procedures (biceps tenotomy/tenodesis, acromio-clavicular joint excision) were noted. Statistical analysis was performed with student t-test to assess improvement in PROM score. Spearman correlation test was used to evaluate association of statin with cuff healing and progression in fatty atrophy.
Results
Our study population included 42 males and 35 females with mean age 60.9?7.0 (range 45–76) years. 38 patients had previous history of hyperlipidemia and were on a statin drug. 19 patients had single row and 58 had double row repair. Mean pre and 12-months post-operative PROM scores were 36.2?20.5 and 76.7?23.6 (ASES), 32.8?19.8 and 67.0?20.5 (constant), and 63.0?15.7 and 23.7?22.9 (DASH score) in statin group. Mean pre and 12-months post-operative scores were 38.7?16.3 and 76.9?25.7 (ASES), 34.6?18.6 and 74.8?19.6 (constant), and 58.8?18.7 and 16.2?19.9 (DASH score) in no-statin group. PROM scores improved significantly in both groups (p<0.01). Cuff re-tear was seen in 14 patients [six (15.78%) and eight (20.51%) in statin and no-statin group respectively]. Progression of fatty atrophy was seen in eight patients [four (10.52%) and four (10.25%) in statin and no-statin group respectively]. The rate of cuff re-tear and progression of fatty atrophy was comparable in both groups. Statin use did not correlate significantly with either cuff healing (Ps=0.049, p=0.692) or progression of fatty atrophy (Ps=0.013, p=0.909).
Conclusion
Our result proves that, contrary to previous literature, statin do not have any effect on rotator cuff healing or fatty atrophy of cuff muscles after repair.
Shoulder
Glenohumeral
Tears
Elderly
MRI
Repair/Reconstruction
Supraespinoatus Tendon Injury
Tendon

### 20178 From open to arthroscopic latarjet; an evaluation of the learning curve of the first 103 cases

Berte Bøe
Ingvild Blich
Ragnhild Øydna Støen
Gilbert Moatshe
Tom Clement Ludvigsen
Norway
Summary
Evaluation of the learning curve after 103 cases of arthroscopic Latarjet resulted in the recognition that the procedure was technically demanding but safe, with good outcomes and low recurrence rates.
Data
Purpose
When changing from a standard open procedure to a novel technique, evaluating the effect of a learning curve is important. The aim of this study was to evaluate two experienced surgeons learning curve of the arthroscopic Latarjet procedure by comparing the outcomes and complications of the first 25 patients with the latter 25 patients. Material: A consecutive cohort of 103 patients operated with arthroscopic Latarjet procedure were prospectively registered from December 2014 until November 2019. Patients in this cohort represent the first cases for the two shoulder surgeons. No conversion to open surgery and no standard open Latarjet procedures were done in this period. All patients had a double screw fixation technique. We prospectively recorded WOSI score preoperatively and at 1 year follow up (FU), and 3D-CT preoperatively, post operatively and at 1 year FU. Patient demographics, intraoperative data, complications, WOSI scores, radiology scores,satisfactgion rate and reoperations were all recorded. Complications were graded according to severity. Two groups; the first and last 25 patients, a total of 50, with complete data sets were compared.
Results
86 of 103 (83%) patients had complete sets of data available for analysis, 12 had incomplete WOSI scores, 5 were lost to FU due to drug abuse(3), death(1) and emigration (1).The patients undergoing arthroscopic Latarjet were predominantly male (90%), and the median age at surgery was 26 years in the first group and 32 years in the latter group. The median number of dislocations before surgery was 10 in both groups, 19 of 50 were reoperations after former instability surgery and we found no significant differences in patient demographics between the groups. Surgery time improved from 130 minutes to 105 minutes. There was no difference in patient postoperative satisfaction (84%), preoperative WOSI (45% in both groups) and postoperative WOSI scores (75% versus 80%). Graft placement and union rates on 3-D CT was better in the latter group than the first group (p<0.05). There were relatively high rates of graft resorption in both groups, 48% and 44% in group 1 and group 2 respectively. There were higher complication rates with a total of 23 minor complications that resolved without a need for intervention in the first group versus 14 in the latter. There were 5 major complications that needed reoperations, 4 in group 1 and 1 in group 2. No cases of recurrent dislocation were recorded and 3 subluxations were recorded in group 1. Discussion: We found an obvious learning curve when it comes to operating time and complications that lead to reoperations when introducing arthroscopic Latarjet. The outcomes in both groups were satisfactory and comparable to previous studies on the Latarjet procedure. There was a relatively high number of resorption of the coracoid graft after one year in both groups, and this finding explains the high number of minor complications. Bone resorption did not seem to influence the clinical result and did not cause any reoperations. These are challenging cases with many previous dislocations, high percentage of bipolar bone loss and previous surgery.
Conclusion
Arthroscopic Latarjet is a technically demanding but safe procedure with good outcomes and low recurrence rates. Minor complications that resolve without a need for intervention are common in the beginning and major complications reduced from 4 (20%) to 1 (4%).
Shoulder
Arthroscopy
Glenohumeral
Instability
Bones
Capsuloligamentous Complex
CT-Scan
Dislocation
Outcome Studies
Physical Examination
Practice Management
Tendon

### 20171 High risk of failure after posterior cruciate ligament reconstruction: study from the norwegian knee ligament registry 2004–2019

Gilbert Moatshe1
R Kyle Martin2
Berte Bøe1
Lars Engebretsen1
1Norway
2USA
Summary
High risk of subjective failure after posterior cruciate ligament reconstruction
Data
Background
Posterior cruciate ligament (PCL) injuries are less common than anterior cruciate ligament injuries (ACL), and usually present with concomitant injuries. Outcomes after PCL reconstruction (PCLR) have been reported to be inferior to ACL reconstruction. Furthermore, combined ligament injuries have been reported to have inferior outcomes compared to isolated PCL injuries.
Purpose
To report on clinical outcomes and failure rates after PCLR and compare isolated PCLR with combined PCL injuries (more than one ligament reconstructed, including PCL).
Methods
All patients who underwent primary PCL reconstruction with or without concomitant ligament injuries registered in the Norwegian Knee Ligament Register from 2004 through 2019 were included. Patient reported outcomes with Knee Injury Osteoarthritis Outcome Scores (KOOS) were collected preoperatively, and postoperatively at two years and five years. Primary outcome measure was failure, defined as either revision surgery or a KOOS quality of life (QoL) subscale below 44. Revision rates were calculated using the Kaplan-Meier analysis and hazard ratios (HR) for revision were calculated using a multivariable Cox regression model.
Results
There were 585 primary PCL reconstructions registered in the period with 176 (30%) isolated PCL reconstructions and 409 (70%) combined reconstructions with a median follow-up time of 7.2 and 7.1 years, respectively. The most commonly used graft for PCL reconstruction was hamstring tendon autograft (69% for isolated PCL reconstruction, 49% for combined injuries). Allografts were used in 18.2% and 27.9% in isolated and combined PCLR, respectively. For isolated PCLR, graft size was recorded in 74 patients (<8 mm n=7, 8–10 mm n=52, >10 mm n=15). Most patients with PCL injuries had poor preoperative knee function as defined by a KOOS QoL <44 (91.2% for isolated PCLR and 84.4% for combined PCL injuries; p=0.08). There were significant improvements in KOOS subscores after surgery in both groups; however, subjective failure (KOOS QoL <44) of isolated PCLR (46.6%) and combined PCLR (44.7%) by two years was common (p=0.81). At five years the subjective failure rates (KOOS QoL <44) of isolated and combined PCLR were 49.3% and 36.7%, respectively (p=0.07). There was no statistically significant difference in revision rates between the groups at two or five years (2.4–3.8%). In a multivariable cox regression model, no factors were associated with revision at 2 years.
Conclusion
Patients who underwent PCLR had improved KOOS scores versus their preoperative state; however, the subjective failure rate was high but few patients underwent revision surgery. Patients with isolated PCL reconstructions can be expected to have similar failure rates as combined ligament reconstructions within the first two years. Future studies should evaluate the impact of recent advancements in PCL surgical and postoperative rehabilitation techniques on outcomes and failure rates.
Knee
Instability
Ligaments
PCL
Repair/Reconstruction
Allograft
Arthroscopy
Autograft
Dislocation
Failed
Outcome Studies
Tears
Trauma

### 19893 Diagnostic accuracy of mri for osteochondral lesions of the talus: a systematic review and a meta-analysis

Bruno S Pereira
João Espregueira-Mendes
Francisco Xará-Leite
Cristina Valente
Pedro Pinho
Joni L Soares Nunes
Daniela Dantas
Tiago Oliveira
Portugal
Summary
Magnetic resonance imaging is accurate to detect osteochondral talus lesions (as compared to arthroscopy) providing good diagnostic performance for diagnostic odds ratio (96.2) and AUC (0.94), and showing high sensitivity (80%) and specificity (96%). Radiologists and orthopaedic surgeons can trust in magnetic resonance imaging results to accurately diagnose osteochondral talus lesions.
Data
Background
Poor diagnosis and inadequate treatment of osteochondral lesions of the talus (OLTs) may result in further pain and progression to osteoarthritis. Magnetic resonance imaging (MRI) has an important role in diagnosing and staging OLTs, but its accuracy has not been systematically established. The purpose of this systematic review with meta-analysis was to evaluate the accuracy performance of MRI (as compared to arthroscopy) in diagnosis OLTs.
Methods
We included studies published up to October 24, 2020 that reported the accuracy of MRI in diagnosing OLTs and using arthroscopy as reference standard. The risk of bias was assessed through the QUADAS-2 tool. Quantitative syntheses with 95% confidence intervals (CI) were performed to calculate the pooled sensitivity, specificity, positive likelihood ratios (LR+) and negative likelihood ratios (LR-), diagnostic odds ratio (DOR) and summary receiver operating characteristic (SROC) curves.
Results
Fourteen studies were included for qualitative analyses and twelve studies were included for quantitative synthesis. A total of 711 participants and 436 OLTs with a weighted mean age of 37.9±5.6 years (mostly males, 77%) were included. The MRI analyses were performed by one or two musculoskeletal radiologists using most commonly a 1.5T MRI. Staging of OLTs was determined using heterogenous grading scales and thus not considered for quantitative analyses. Pooled sensitivity (80%, 95% CI 67–89%), specificity (96%, 95% CI 82–98%), LR+ (19.7, 95% CI 4.16–93.40), LR- (0.20, 95% CI 0.12–0.36) and DOR (96.20, 95% CI 19.31–479.28) were obtained. The SROC curve showed an excellent area under the curve (AUC) for diagnosing OLTs (0.94, 95% CI 91–96). The hierarchical SROC was comparable to results from the bivariate model and was symmetrical (ß=0.588, 95% CI 0.342–1.520, p=0.215). The value of ? was 4.237 (95% CI, 2.98 5.49), indicating a high diagnostic accuracy. The I-squared was 79.8%, 91.3%, 83.4%, 79.4% and 94.7% for sensitivity, specificity, LR+, LR-, and DOR, respectively, indicating heterogeneity. The Cochrane Q statistic was 32.20 (P?<?0.05) for AUC estimation, indicating that heterogeneity was likely due to non-threshold effects. After inferences by the bivariate model, the proportion of heterogeneity likely due to threshold effect was 27%. The pre-test probability of 25%, 50% and 75% showed that a positive result improved the post-test probability up to 87%, 95% and 98%, while a negative result decreased the post-test probability to 6%, 17% and 38%. Sensitivity analysis (goodness-of-fit, bivariate normality, influence and outlier detection analyses) demonstrated that the bivariate model was moderately robust and did not identify outliers. Five studies presented high risk of selection bias and when excluding these 5 studies, the diagnostic features were similar; the DOR was considerably lower (67 versus 96) but the CIs were very large. Meta-regression (age, time from MRI to arthroscopy, magnetic field intensity) showed no statistical correlation. Publication bias was negligible and not statistically significant (p=0.56), showing a symmetric the funnel plot.
Conclusion
MRI examination is accurate to detect OTLs (as compared to arthroscopy) providing good diagnostic performance for DOR and AUC, and showing high sensitivity and specificity.
Ankle/Foot/Calf
Cartilage
MRI

### 19942 The results of 16s dna deep sequencing in culture-negative periprosthetic joint infections with draining sinus tract

Nicole Kennard
Arianna Mixon
Aniruth Srinivasaraghavan
Gerhard E Maale
USA
Summary
Next-generation 16S deep sequencing is shown to be more accurate, reliable and provide more in-depth analysis for the detection of microbial and fungal growth when compared to traditional culture methods.
Data
Background
Traditional culture methods have long been used to identify the presence of organisms in periprosthetic joint infections (PJI). However, increased false negative rates have decreased the clinical applicability of traditional culture methods. In cases where joints present with acute inflammation, clinicians will often treat with antibiotics and surgical debridement despite negative cultures. Prosthetic joints can also be infected despite cultures from aspirates and intraoperative samples showing negative results. Retrieval rates of less than 15% are seen at the time of surgery in patients with open draining sinus tracts, even for one organism. Furthermore, current literature has found a stark difference in accuracy between culture data and modern molecular diagnostic methods. To overcome deficiencies in traditional culture, more and more clinicians are looking for more robust organism identification methods such as Next Generation 16S DNA deep sequencing technologies.
Methods
24 patients were identified with open draining sinus tracts around an infected prosthesis, including 16 knees, 6 hips, 1 humerus, and 1 femur. All patients had several operations prior to referral to our clinic. All wounds were open and were culture negative. Each open wound was swabbed and underwent PCR and 16S deep sequencing on an orthopedic platform by Microgen. Upon receipt of the sample, Microgen extracts the microbial DNA and runs it through the Roche Light Cycler for PCR sequencing and the Illumina MiSeq for clonal amplification in order to gather data for analysis. The platform consists of 50,000 species of bacteria in their library with a readout from Illumina.
Results
None of this patient population had a positive culture of their draining sinus wound. Of these 24 patients, 7 of the open wounds were monomicrobial and the other 17 were found to be polymicrobial PJI, with an average of 2.5 bacterial species per culture. One patient also had a fungal species detected. Of the patients with polymicrobial infections, 6 grew both gram-positive and gram-negative bacteria.
Conclusion
Our findings indicate that in our entire patient population, culture was not sufficient to detect bacterial infection in patients following joint replacement arthroplasty. Next-generation 16S deep sequencing is shown to be more accurate, reliable and provide more in-depth analysis for the detection of microbial and fungal growth. Additionally, it has utility in identifying antibiotic resistance and guiding more suitable treatment utilizing antibiotic local carriers and systemic antibiotics.
Knee
Arthritis
Failed
Aedema
Arthroplasty
Basic Science
Biologics
Bone Scan
Bones
Cartilage
CT-Scan
Implant
Infection
Physical Examination
X-ray

### 19864 Posterior tibial plateau impaction fractures are not associated with increased knee instability: a quantitative pivot shift analysis

Brian M Godshaw
Joshua C Setliff
Jonathan D Hughes
Volker Musahl
USA
Summary
Posterolateral tibial plateau impaction fractures in the setting of ACL tears do not significantly impact rotatory knee instability.
Data
Background
Impaction fractures of the posterolateral tibial plateau have been well described in association with injury to the anterior cruciate ligament (ACL). No consensus has been reached on the role these injuries play in rotatory knee stability, with some studies suggesting that increasing severity of the fracture leads to increased rotatory knee instability. The purpose of this study was to evaluate these injuries and how they contribute to rotatory knee stability via the use of quantitative data.
Methods
Two hundred eighty-four consecutive patients with complete ACL tears had data prospectively collected. All patients underwent ACL reconstruction by a single, fellowship-trained orthopaedic sports medicine surgeon. Basic demographic information was obtained via chart review. The magnetic resonance imaging (MRI) of each patient was reviewed to identify posterolateral tibial plateau impaction fractures. Patients were placed into two cohorts: fractures or no fractures. The cohort with fractures were further categorized based on fracture morphology: extra-articular, articular-impaction, or displaced-articular fragment. All data were collected during the exam under anesthesia (EUA). This included a standard, subjectively graded, pivot shift test graded by the examiner and quantitative data including the Rolimeter measure of anterior tibial translation, quantitative pivot shift (QPS) exam, and acceleration during the pivot shift. The PIVOT application, a previously verified application for a computer tablet, was used for the QPS. An accelerometer was used to obtain the knee’s acceleration during the pivot shift exam. These quantitative exams were compared to the contralateral knee. The quantitative pivot, Rolimeter, and accelerometer were used to remove any subjective bias of the physical exam. Significance was met if p<0.05.
Results
The prevalence of posterolateral impaction fractures was 39.44%. Of the fractures, 63.4% were extra-articular, 25.0% were articular-impaction, and 11.6% were displaced-articular. There were no differences in patient demographics or time from injury to surgery. There was no difference in the average of subjectively graded pivot shift in those with fractures vs those without (1.8±0.3 vs1.7±0.4, respectively, p=0.81). Similarly, the QPS revealed no statistically significant difference regardless of presence or not of a fracture (2.4±1.6 mm vs 2.7±2.2 mm, respectively, p=0.26). Anterior tibial translation measurements were not statistically significant different whether or not a fracture was present (5.5±2.7 mm vs 5.4±2.6 mm, respectively, p=0.74). The acceleration of the knee during the pivot did not reveal a statistically significant difference with or without a fracture (1.7±2.3m/s2 vs 1.8±3.2m/s2, respectively, p=0.86). When the fractures were further subdivided, there were no statistically significant differences noted in any of the measured exams between the variants.
Conclusion
The results of this study demonstrate posterolateral tibial plateau impaction fractures in the setting of ACL tears do not significantly impact rotatory knee instability. Therefore, surgeons may consider in-situ fixation of these injuries in patients with ACL tears.
Knee
ACL
Instability
Ligaments
Bones
Cartilage
MRI
Outcome Studies
Physical Examination
Sport Specific Injuries
Tears
Tibial Plateau Fracture
Trauma

### 19829 Kinematic changes are associated with improved outcomes following superior capsular reconstruction

Clarissa LeVasseur
Gillian Kane
Jonathan D Hughes
James J Irrgang
William Anderst
Albert Lin
USA
Summary
Changes in scapular and GH kinematics following superior capsular reconstruction suggest a convergence towards a more similar and potentially more efficient movement pattern following superior capsular reconstruction.
Data
Introduction
Patients with irreparable rotator cuff tears exhibit functional limitations while performing activities of daily living. One viable treatment is superior capsular reconstruction (SCR). SCR has been shown to restore stability of the glenohumeral (GH) joint in cadavers1, but its effect on in vivo scapular and humeral motion is unknown. The aims of this study were to determine the effect of SCR on in vivo scapular and humeral kinematics during a functional hand-to-head motion and to identify associations between shoulder kinematics and patient-reported outcomes (PROs). We hypothesized that the functional task would be accomplished by using more GH based movement and less scapular motion after SCR, and there would be a positive correlation between kinematics changes and improved PROs.
Methods
Ten patients (8M, 2F, age 63 ± 7 years) with irreparable RCT consented to participate in this prospective IRB-approved study. ASES, DASH, and WORC surveys were completed before (PRE) and 1-year after (1YR-POST) SCR. PRE and 1YR-POST, participants were seated and instructed to move their hand from their lap to the back of their head while synchronized biplane radiographs of the shoulder were collected at 50 images/s for 3 trials. Subject-specific CT-based bone models of the humerus and scapula were matched to the synchronized radiographs using a validated volumetric tracking technique2 to determine scapular and GH kinematics. PRE to 1YR-POST differences in end-range rotational orientation and the total contribution of each rotational component to the overall movement were evaluated using a paired t-test. Among-subject variability in rotational contributions to the motion was calculated each test day, and PRE to 1YR-POST differences were analyzed using a paired t-test. Correlations between rotation contributions and PROs were evaluated with Pearson’s correlation. Significance was set at p<0.05 for all tests.
Results
End-range GH I/E rotation was 12° lower (p=0.03) while end-range scapular protraction was 6° degrees higher 1YR-POST compared to PRE (p=0.01). Inter-subject variability in rotational contributions to the movement decreased 4.0% in GH abduction and 2.6% in GH I/E rotation (p=0.047, and p=0.005, respectively) from PRE to 1YR-POST. The PRE to 1YR POST change in contribution from GH abduction was positively correlated to the change in contribution from GH I/E rotation (R=0.8, p=0.001) and negatively correlated to the change in contribution from scapular protraction (R=-0.94, p=0.001). Changes in the horizontal plane elevation contribution were positively correlated with changes in ASES scores (R=0.635, p=0.048).
Discussion
Changes in rotational contributions of the scapula and humerus to the hand-to-head movement after SCR were inconsistent across subjects, however, inter-subject variability in GH abduction and I/E rotation were reduced following surgery, suggesting the participants’ movement strategy converged toward a more similar and possibly more efficient movement pattern following SCR. End-range I/E rotation decreased and scapular protraction increased, which contradicts our first hypothesis. In addition, increased GH horizontal plane elevation contribution following surgery was associated with improved ASES scores, supporting our second hypothesis. This may be consistent with improved glenohumeral kinematics and efficiency of movement during a functional task following SCR.
Shoulder
Allograft
Arthroscopy
Glenohumeral
Osteoarthritis
Tears
Arthro-MRI
Biomechanics
Bones
Outcome Studies
Physical Examination

### 19830 Surgical technique and prosthesis geometry affect in vivo kinematics, strength, and contact path after reverse shoulder arthroplasty

Clarissa LeVasseur
Ajinkya Rai
Gillian Kane
Alexandra Santina Gabrielli
Jonathan D Hughes
William Anderst
Albert Lin
USA
Summary
In vivo kinematics and strength data suggest surgical technique affects in vivo contact patterns and strength after reverse shoulder arthroplasty.
Data
Introduction
Reverse shoulder arthroplasty (RSA) is a procedure to reduce pain and restore function in patients with rotator cuff arthropathy1. In vitro studies suggest that modifications in prosthesis design and surgical technique can improve functional outcomes after RSA2, but little work has been done to quantify in vivo kinematics following RSA. The aim of this ongoing study is to determine the effects of surgical technique and prosthesis geometry on in vivo functional outcomes after RSA. We hypothesized that greater humeral retroversion would be related to a more posterior contact path and that greater lateralization would be related to greater strength and better patient-reported outcomes (PROs).
Methods
17 patients received RSA (10M, 7F, age 69.5±7.4 years) using a standard 145-degree humeral implant (Wright Med/Tornier) or 135-degree humeral implant (Arthrex) within 2.5±1.2 years of participating in this IRB-approved study. Surgical parameters of glenoid lateralization and humeral retroversion were recorded from surgical notes. ASES, DASH, and Constant-Murley surveys (CMS) were completed at testing. Participants performed 3 trials of scapular plane abduction while synchronized biplane radiographs of the shoulder were collected at 50 images/s for 2 seconds. Subject-specific models of the humerus and scapula with respective implants were created from CT scans and matched to the biplane radiographs to measure scapular and humerus motion with sub-millimeter accuracy3. The center of the contact region of the polyethylene and glenosphere was determined at 5-degree increments of glenohumeral (GH) abduction and averaged across trials. Isokinetic torque was recorded over the full ROM for flexion/extension, ab/adduction, and internal/external rotation at 30°/second using a Biodex. Both the peak torque and the total work done were used to quantify strength. Pearson’s correlations were used to identify associations between the anterior-posterior and superior-inferior location of the center of contact at every 5° of GH abduction and surgical parameters. Spearman’s correlations were used to identify associations between strength, surgical factors, and patient-reported outcomes (PROs) with significance set at p<0.05.
Results
Ten patients had 20° of humeral retroversion, four had 30°, and two had 40°. Ten patients had 0-2.0 mm lateralization, three had 2.1–4.0 mm, and four had 4.0–7.0 mm. During abduction, the center of contact path was posterior and inferior to the center of the glenosphere in all subjects. Increased retroversion was positively correlated with a more superior location of the center of contact between 35° and 60° of GH abduction (all p<0.01; R>0.85). No other correlations were found for center of contact (all p>0.31). Total adduction work was correlated with lateralization (?=0.58, p=0.015), and peak torque in external rotation was correlated with lateralization (?=0.57, p=0.017). CMS was correlated with total work in abduction, external and internal rotation (all ?=0.48, all p<0.047).
Discussion
Retroversion is associated with in vivo contact kinematics, and increased glenoid lateralization is associated with increased strength and better PROs after RSA, supporting our hypothesis. The results indicate surgical technique is associated with strength and PROs. Our results provide in vivo evidence confirming previous computational modeling and cadaver-based studies that demonstrated increased strength following RSA with lateralized designs.
Shoulder
Arthroplasty
Glenohumeral
Osteoarthritis
Biomechanics
Bones

### 20157 Age, time from injury to surgery and quadriceps strength affect the risk of revision surgery after primary acl reconstruction

Riccardo Cristiani
Gunnar Edman
Karl Eriksson
Anders Stalman
Sweden
Summary
Younger age (< 25 years), shorter time from injury to primary ACLR (< 12 months) and a quadriceps strength LSI of => 90% 6 months after primary ACLR increased the odds of revision ACLR within 2 years.
Data
Background
There is a need for a comprehensive and detailed analysis of preoperative, intraoperative and postoperative risk factors for revision ACLR. An awareness of the effect of multiple factors on the risk of revision ACLR could help clinicians to counsel patients undergoing primary ACLR about this complication. In addition, knowledge of potentially modifiable risk factors for revision ACLR might be used to target these factors and reduce the risk of this serious event.
Purpose
To identify preoperative, intraoperative and postoperative factors associated with revision ACLR within 2 years of primary ACLR.
Methods
Patients who underwent primary ACLR at our institution, from January 2005 to March 2017, were identified. The primary outcome was the occurrence of revision ACLR within 2 years of primary ACLR. Patients who underwent revision ACLR at our institution or other institutions in the country were identified through their unique personal identity number in the Swedish National Knee Ligament Registry. Univariate and multivariate logistic regression analyses were used to evaluate preoperative (age, gender, body mass index [BMI], time from injury to surgery, pre-injury Tegner activity level), intraoperative (graft type, graft diameter, medial meniscus [MM] and lateral meniscus [LM] resection or repair, cartilage injury) and postoperative (side-to-side [STS] KT-1000 anterior laxity, limb simmetry [LSI] for quadriceps and hamstring strength and single-leg-hop test performance at 6 months) risk factors for revision ACLR.
Results
A total of 6,510 primary ACLRs were included. The overall incidence of revision ACLR within 2 years was 2.5%. Univariate analysis showed that age < 25 years, BMI < 25, time from injury to surgery < 12 months, pre-injury Tegner activity level => 6, LM repair, STS laxity > 5 mm, quadriceps strength and single-leg-hop test LSI of => 90% increased the odds, whereas MM resection and the presence of a cartilage injury reduced the odds of reivision ACLR. Multivariate analysis revealed that revision ACLR was significantly related only to age < 25 years (OR 6.25; 95% CI, 3.57 - 11.11; P < 0.001), time from injury to surgery < 12 months (OR 2.27; 95% CI, 1.25 - 4.17; P = 0.007) and quadriceps strength LSI of => 90% (OR 1.70; 95% CI, 1.16 - 2.49; P = 0.006).
Conclusions
Age < 25 years, time from injury to surgery < 12 months and 6-month quadriceps strength LSI of => 90% increased the odds of revision ACLR within 2 years of primary ACLR. Understanding the risk factors for revision ACLR has important implications when it comes to the appropriated counselling for primary ACLR. We have analyzed a large spectrum of potential risk factors for revision ACLR in a large cohort. Advising patients regarding the results of an ACLR should also include potential risk factors for revision surgery.
Knee
ACL
Failed
Instability
Ligaments
Repair/Reconstruction
Meniscus
Single Bundle

### 20096 Modified lemaire anterolateral tenodesis improves objective stability and reduces failure rate when associated with acl reconstruction in skeletally immature patients

Simone Perelli1
Veronica Montiel1
Mario Formagnana2
Rodolfo Morales-Avalos3
Joan C Monllau1
1Spain
2Italy
3Mexico
Summary
Adding an anterolateral modified Lemaire tenodesis to hamstring anatomic ACL reconstruction improve objective stability and reduce failure rate skeletally immature patients with a low risk of growth-related changes.
Data
Objective
Anterior cruciate ligament (ACL) ruptures in pediatric patients are becoming increasingly common and the reconstruction failure rates range from 8.7% to 20% regardless of the technique and graft used. Combining extraarticular tenodesis with ACL reconstruction has been reported to decrease failure rate and improve objective stability in adult patients. The aim of the present study is to evaluate clinical result of adding an extraarticular procedure in skeletally immature ACL deficient knees. Method: A multicentric comparative study was conducted with a minimum 2-year follow-up, evaluating skeletally immature patients who had undergone an anatomic hamstring ACL reconstruction (AHACLR). 32 consecutive patients underwent combined AHACLR and modified Lemaire anterolateral tenodesis between January 2017 and December 2018 were prospectively evaluated (Group 1). The control group was an historical cohort of skeletally immature patients (n=34) that had had surgery from October 2014 to December 2016 (Group 2). In the control group only AHACLR have been performed. Patients were classified as skeletally immature when both tibial and femoral physis were still open on MRI. Bone skeletal age was evaluated on X-Ray. The femoral tunnel was performed using a physeal-sparing technique and a trans-physeal tibial tunnel was drilled in every case. A Lemaire modified anterolateral tenodesis was additionally performed in the patients of group 1. The exclusion criteria included rupture of other ligament rather than ACL, root or bucket handle meniscal tears, ramp lesion or any cartilage injury that needed surgical treatment. Graft diameter, Pedi-IKDC subjective knee evaluation, graft failure and return to sports were recorded. Pre and postoperative objective laxity of the knee was also measured using KT-1000 arthrometer and the KiRA triaxial accelerometer. Postoperative lower limb deformity or growth disturbances were recorded.
Results
The mean age in group 1 was 13.8 (range 12–16) years and 14 (range 12–16) years in group 2 (p=0.48). The mean graft diameter was 8.2 (range: 7–9) mm, with no significant differences between the groups (p=0.63). The mean follow-up was 26.1 ± 4.2 months for group 1 and 29.6 ± 7.2 months in group 2 (p = 0.11). Three patients had a <3° genu valgus deformity on the operated limb, two of which belonged to group 1 and one to group 2. Both better anteroposterior stability measured with KT-1000 (p = 0.041) or KiRA (p= 0.033) and better rotational stability measured with a KIRA (p= 0.019) have been detected in group 1. The graft failure rate was also lower in group 1 (11,8% group 2 vs 6,2% group 1; p = 0.042). The patients in group 1 had a return to sports rate of 91%, while in group 2 this rate was of 85%, without statistical difference (p=0.069). The Pedi-IKDC subjective knee evaluation recorded for both groups showed no difference between the 2 groups (p = 0.27).
Conclusion
From the data obtained in the present study we can conclude that adding an anterolateral modified Lemaire tenodesis to hamstring anatomic ACL reconstruction improve objective stability and reduce failure rate in skeletally immature patients with a low risk of growth-related changes.
Knee
Anterolateral Ligament
Arthroscopy
Instability
Ligaments
Outcome Studies
Physical Examination

### 20017 Early postoperative results of the first latin-american experience with robotic-arm-assisted TKA versus conventional technique

David H Figueroa
Rodrigo Guiloff
Juan Jose Sotomayor
Alberto Alarcon
Alex Vaisman
Rafael Calvo
Chile
Summary
The early clinical postoperative results of this first Latin-American comparative experience of robotic-arm-assisted TKA versus conventional technique showed lower opioids requirements and faster functional recovery of ambulation in those patients operated with the robotic system; nevertheless, surgical times were higher, without differences in postoperative complications. There were no statistica
Data
Early results with robotic-arm-assisted total knee arthroplasty (TKA) are encouraging; nevertheless, literature might be unrepresentative, as it comes mostly from Anglo-Saxon and Asian countries, and there is limited experience and no comparative clinical reports in Latin America. This study aims to compare the early postoperative results of the first Latin-American experience with robotic-arm-assisted TKA versus conventional TKA. A cohort study was performed, including 181 consecutive patients (195 knees) with advanced symptomatic knee osteoarthritis (OA) undergoing primary TKA between March 2016 and October 2019. The cohort included 111 consecutive patients (123 knees) undergoing conventional TKA, followed by 70 consecutive patients (72 knees) undergoing robotic-arm-assisted TKA. The same surgical team (surgeon 1 and surgeon 2) performed all procedures. Patients with previous osteotomy, posttraumatic OA, and revision components were not considered. The same anesthetic and rehabilitation protocol was followed. The investigated clinical outcomes were: surgical tourniquet time, time to home discharge, time to ambulation, postoperative daily pain [Visual Analog Scale (VAS)], opioid use, range of motion (ROM), blood loss, complications, and postoperative mechanical axis. The early clinical postoperative results of this first Latin-American comparative experience of robotic-arm-assisted TKA versus conventional technique showed lower opioids requirements and faster functional recovery of ambulation in those patients operated with the robotic system; nevertheless, surgical times were higher, without differences in postoperative complications. There were no statistical differences for the other clinical outcomes.
Knee
Arthroplasty
Cartilage
Osteoarthritis

### 20077 Is length change pattern of the posterolateral corner of the knee restored by current reconstruction techniques?

Johannes Glasbrenner
Michael J Raschke
Andre Frank
Christian Peez
Thorben Briese
Elmar Herbst
Christoph Kittl
Germany
Summary
Length change pattern of current reconstruction techniques of the posterolateral corner of the knee were compared in a biomechanical study.
Data
Background
Several operative techniques are used by knee surgeons to treat instability of the posterolateral corner of the knee (PLC). The purpose of the present study was to examine the length change pattern of current reconstruction techniques of the PLC and compare them to length change pattern of the corresponding anatomic structures. It was hypothesized, that anatomic reconstructions (according to LaPrade or Frosch) would better mimic length change pattern of the native PLC than isometric reconstructions (according to Arciero, Larson or modified Larson). Study Design: Controlled laboratory study.
Methods
In 8 fresh frozen human cadaveric knees dissection of the lateral collateral ligament (LCL), popliteus tendon (PT) and the popliteofibular ligament (PFL) was performed. Quadriceps muscle was loaded physiologically using cables and hanging weights, according to the muscle fiber orientations and cross-sections, with the knee mounted in a custom-made open chain flexion-extension rig. Pins were inserted at the anatomic insertions of the LCL, PT and PFL and at the insertion of reconstructions techniques according to Larson, Arciero, LaPrade, Bousquet and Frosch. Threads were mounted between these pins. Length change pattern was measured using a rotary encoder across the range of motion from 0–120°. Statistical analysis was performed using a 2-way repeated measurements ANOVA with Bonferroni correction.
Results
Length change pattern of the native LCL was mimicked best by the reconstruction of the PLC according to LaPrade (p = n.s. between 0–120° of flexion). Reconstruction of the PLC according to Arciero and Larson led to significantly less lengthening between 40 and 120° of flexion (p < 0.05 each). Modified Larson reconstruction led to less lengthening between 50 and 120° of flexion (p < 0.05). Length change pattern of LCL reconstruction according to Bousquet differed significantly to the native LCL between 10–120° of flexion (p < 0.05). Reconstructions according to Arciero, Larson, modified Larson, LaPrade and Frosch were all able to restore length change pattern of the native PT (p = n.s. between 0–120° of flexion each).
Conclusion
Reconstruction of the PLC according to LaPrade best mimicked length change pattern of the native LCL, whereas reconstruction according to Arciero, Larson, modified Larson and Bousquet only partially mimicked length change pattern of the native LCL. Length change pattern of the native PT was restored by all tested reconstruction techniques.
Knee
Autograft
Instability
Ligaments
Posterolateral
Posterolateral Corner
Biomechanics
Capsuloligamentous Complex
Tears

### 20135 Coach education improves implementation of ACL injury prevention programs: a cluster-randomized controlled trial

Daphne Ling
Caroline Boyle
Brandon Schneider
Joseph Janosky
James Kinderknecht
Robert G Marx
USA
Summary
Coaches should receive in-person training on neuromuscular training and how to deliver alignment cues to their athletes while performing the injury prevention exercises.
Data
Introduction
Despite evidence of its efficacy, neuromuscular training (NMT) has had limited effectiveness due to poor adherence by sports coaches. Our objective was to determine the effect of an educational workshop on adherence to NMT recommendations among high school coaches.
Methods
A total of 21 teams in 8 high schools (unit of randomization) were randomized to the intervention or control group. Twelve boys’ and 9 girls’ teams in a variety of sports were enrolled. Coaches in the intervention group participated in a 60-minute education workshop to teach effective implementation of a NMT program and also received print materials. Coaches in the control group received the same print materials. Eight data collectors were trained to observe each team’s practice/game 2–3 times a week. They completed a study questionnaire to identify the NMT exercise and whether the coach (1) delivered exercise instructions and (2) provided alignment cues (both yes/no).
Results
A total of 399 practices/games were observed over 2 seasons. A greater proportion of coaches in the intervention group provided alignment cues to correct improper technique compared to the control group [difference=0.04 (95% CI: 0.01, 0.07, p=0.006]. There was a similar proportion of coaches in the intervention and control groups who provided exercise instructions [difference=0.01 (95% CI: −0.02, 0.04), p=0.44]. More coaches in the intervention group completed a full NMT program [OR=4.62 (1.22, 17.50), p=0.02].
Discussion
Coach education can improve adherence to a NMT program and delivery of alignment cues. Coaches should receive in-person training on NMT and how to deliver alignment cues to their athletes while performing the exercises. This study was funded by an ISAKOS Clinical Outcomes Research Grant.
Orthopaedic Sports Medicine
Preventative Sports Medicine
Tears
ACL
Epidemiology
Evidence Based Medicine
Female Athletes
Gender Specific
Knee
Ligaments
Outcome Studies
Sport Specific Injuries
Sport Specific Population

### 20106 Survivability of primary anterior cruciate ligament reconstructions in a physically high demand population

Ashley Bee Anderson
Travis Dekker
Veronika Pav
Timonthy C Mauntel
Matthew T Provencher
John M Tokish
Jon F Dickens
USA
Summary
The overall clinical failure rate of service members with ACLR is nearly 18% with minimum 4- year follow-up, where more patients are likely to fail due to revision surgery than medical separation.
Data
Background
Anterior cruciate ligament tears and anterior cruciate ligament reconstruction (ACLR) are common in young athletes. The modifiable and non-modifiable factors contributing to ACLR failure and reoperation are incompletely understood. The purpose of this study was to determine ACLR failure rates in a physically high-demand population and identify the patient specific risk factors that portend to failure.
Methods
A consecutive series of military service members with ACLR with and without concomitant procedures (meniscus [M] and/or cartilage [C]) done at military facilities between October 2008 to September 2011was completed via the Military Health System Data Repository. Patients had to be continuously enrolled with no history of knee surgeries for two years prior to the primary ACLR. ACLR failure was defined as revision ACLR or the inability to return to the minimum military physical standards (medical separation) within four years following the primary ACLR. Kaplan-Meier survival curves were estimated and evaluated with Wilcoxon test. Cox Proportional Hazard Models calculated hazard ratios (HR) with 95% confidence intervals (95% CI) to identify demographic and surgical factors that influenced ACLR failure for the isolated ACLR (KA), ACLR Meniscus (KMA), ACLR Cartilage (KCA), ACLR Meniscus and Cartilage (KAMC).
Results
Of the 2,735 primary ACLRs included in the study, 17.7% experienced ACLR failure within four years, including 9.5% (261/2,735) undergoing revision ACLR and 8.2% (224/2,735) due to medical separation. The factors that increased failure include: Army Service (HR 2.188, 95% CI: 1.668, 2.870), >180 days from injury to ACLR (HR 1.550, 95% CI: 1.157, 2.076), tobacco use (HR 1.429 95% CI: 1.174, 1.738), and younger patient age (HR 0.977, 95% CI: 0.958, 0.996).
Conclusion
The overall clinical failure rate of service members with ACLR is 17.7% with minimum four year follow-up, where more patients are likely to fail due to revision surgery than medical separation. The cumulative probability of survival at for years was 78.5%. Smoking cessation and treating ACLR patients promptly are modifiable risk factors impacting either graft failure or medical separation.
Knee
ACL
Ligaments
Arthroscopy
Epidemiology
Evidence Based Medicine
Outcome Studies
Practice Management
Professional Athletes/Olympians
Sport Specific Population
Tears

### 20119 Evaluation of medial patellofemoral ligament reconstruction in inmature skeleton. A comparative study between two techniques

Juan Miguel Del Castillo
Martín Sierra
Juan Dupont
Johan von Heideken
Uruguay
Summary
Our study evaluates the functional results of two groups of patients treated by two different techniques of LPFM reconstruction, one anatomic with autologous semitendinosus and the other non-anatomic with autologous quadrcipital hemitendon
Data
Patellofemoral dislocation accounts for 3% of traumatic knee injuries, with two-thirds occurring in patients under 20 years of age. Recurrence after the second episode is greater than 50%, which can cause great functional limitation in young patients, reducing their quality of life. The immature skeleton implies a therapeutic problem since the remaining growth potential must be preserved. Medial patellofemoral ligament (MPFL) is the main medial stabilizer of the patella at 30° flexion, currently its anatomic reconstruction preserving the physis appears to be the best option in these cases until they are candidates for other corrective surgeries. Our study evaluates the functional results of two groups of patients treated by two different techniques of MPFL reconstruction, one anatomic with autologous Semitendinosus (ST) and the other non-anatomic with autologous quadricipital hemi tendon (QT). Both groups were evaluated through the Kujala score before surgery and during follow-up. Means and score items were compared using Wilcoxon signed-rank test. Twenty-two knees were evaluated, eleven in each group. Patient’s age ranged between 8 and 15 years old. The mean follow-up was 19.4 months (range 7–30). Results show an improvement in the average Kujala scores for the ST group from 51 to 88 and in the QT group from 52 to 97. Kujala score was statistically significantly higher in the postoperative evaluation with both technics (p-value 0.003 for both groups) while we did not find any statistical difference between both techniques in Kujala score at follow up. Only one case of patella redislocation from the QT group was registered during the study period. In conclusion, we can affirm that MPFL reconstruction is a valid therapeutic option for patellofemoral dislocation and the proposed techniques are reliable choices in patients with immature skeleton.
Orthopaedic Sports Medicine
Instability
Outcome Studies
Repair/Reconstruction
Acute Patella Dislocation
Arthroscopy
Autograft
Bones
Capsuloligamentous Complex
Dislocation
Hamstrings Tendon Injury
Knee
Ligaments
MRI
Muscle
Patellar Fracture
Patellofemoral
Patellofemoral Ligament Rupture
Physical Examination
Recurrent Subluxation and Dislocation
Sport Specific Injuries
Tendon
X-ray

### 20189 Low percentage of surgeons meet the minimum recommended unicompartmental knee arthroplasty usage thresholds: analysis of 3,037 surgeons from three national joint registries

Antonio Klasan
David A Parker
Peter L Lewis
Simon W Young
Austria
Summary
A low number of surgeons is meeting the UKA thresholds.
Data
Purpose Unicompartmental knee arthroplasty (UKA) has a faster recovery and less perioperative morbidity than total knee arthroplasty (TKA), but has a significantly higher revision rate. The reported usage of UKA is around 10% in the UK, Australian and New Zealand joint registries. However, some authors recommend that a higher UKA usage of 20%, or a minimum 12 UKA cases per year, would reduce revision rates. The purpose of this study was to analyze the percentage of surgeons performing the recommended thresholds in these 3 registries. Methods Data from the UK, Australian and New Zealand registry databases was utilized from the time period since their respective introduction until 2017. All primary TKA and UKA performed for the diagnosis of osteoarthritis by surgeons with more than 100 recorded knee arthroplasties in their respective registry were included. The results between the registries were compared and a pooled analysis was performed. The number of surgeons meeting the recommended caseload of >20% UKA yearly or 12 UKA cases yearly was calculated. Results We identified 3,037 knee surgeons performing 1,556,440 knee arthroplasties, of which 131,575 were UKA (8.45%). Over 50% of knee surgeons in each registry had a proportion of less than 5% UKA of their knee replacement procedures. After pooling of data, median surgeon UKA usage was 2.0% (IQR 0–9.1%). The percentage of surgeons meeting the proposed caseload criteria was highest in New Zealand, 16.3%, followed by the UK at 12.4% and Australia 11.3% (p=0.28).
Conclusion
More than 50% of knee surgeons in UK, Australian and New Zealand joint registries perform less than 5% of UKA yearly. The majority of experienced knee surgeons are not meeting the recommended minimum thresholds, which might indicate that the recommended thresholds are not feasible for the vast majority of knee surgeons. The reasons behind this require further research.
Knee
Arthroplasty
Osteoarthritis

### 20190 The effect of surgeon usage of medial unicompartmental knee arthroplasty on both unicompartmental and total knee arthroplasty outcomes

Antonio Klasan
Mei Lin Tay
Chris Frampton
Simon W Young
New Zealand
Summary
Increased UKA usage decreases TKA outcomes.
Data
Background
Surgeons with higher unicompartmental knee arthroplasty (UKA) usage have lower UKA revision rates. However, in order to increase UKA usage in arthroplasty patients, surgeons will decrease their usage of total knee arthroplasty (TKA). The purpose of this study was to investigate the influence of UKA usage on survivorship and patient reported outcomes (PROMs) of UKA, TKA, and UKA/TKA results.
Methods
Using the New Zealand Registry Database, surgeons were divided into 6 cluster groups, based on their UKA usage:<1%, 1–5%, 5–10%, 10–20%, 20–30% and >30%. A comparison of UKA, TKA and UKA/TKA revision rates as well as PROMs using the Oxford Knee Score (OKS) between the groups was performed.
Results
We identified 91,895 knee arthroplasties, of which 8,271 were UKA. Surgeons with higher UKA usage had lower UKA revision rates, but higher TKA revision rates. The lowest TKA and UKA/TKA revision rates were observed in the 1–5% UKA cluster, compared to highest TKA and UKA/TKA in the >30% UKA cluster (Log Rank p<0.001 TKA; p<0.001 UKA/TKA). No clinically important differences in combined OKS scores were seen between UKA usage groups at 6 months, 5 years, or 10 years.
Conclusions
Surgeons with higher UKA usage have lower UKA revision rates, however, their UKA/TKA revision rate is the highest. An increase in TKA revision rate was observed for highest volume UKA users (>30%). Increased UKA usage did not result in higher PROMs. Surgeons need to be aware of the impact of increasing UKA usage on the UKA/TKA revision rate and clinical outcomes.
Knee
Arthroplasty
Osteoarthritis

### 20192 Measuring appropriate need for unicompartmental knee arthroplasty: results of the manuka study

Antonio Klasan
Matthias Luger
Rainer Hochgatterer
Simon W Young
Austria
Summary
UKA is appropriate in 15% of patients, if more than radiologic criteria are applied.
Data
Aims: Indications for unicompartmental knee arthroplasty (UKA) are controversial. Studies based solely on radiographic criteria suggest up to 49% of patients with knee osteoarthritis (OA) are suitable for UKA. In contrast, the ‘Appropriate use criteria’ (AUC), developed by the American Academy of Orthopedic Surgeons, applies both clinical and radiographic criteria to guide surgical treatment of knee OA. The aim of this study was to analyse patient suitability for TKA, UKA and osteotomy using both radiographic criteria and AUC in a cohort of 300 consecutive knee OA patients.
Patients and Methods
Included were consecutive patients with clinical and radiographic signs of knee OA referred to a specialist clinic. We collected demographic data, radiographic wear patterns and clinical findings that were analyzed using the AUC. Patients with bilateral knee OA were analyzed separately for each knee. We compared the radiographic wear patterns with the treatment suggested by the AUC as well as the Surgeon Treatment Decision.
Results
There were 397 knees in 300 patients available for analysis. Median age was 68 [IQR 15], BMI 30 [6] with 55% females. We found excellent consistency for both the radiographic criteria and the AUC criteria. Based on radiological criteria, 41% of knees were suitable for UKA. However, when using the AUC criteria, UKA was the appropriate treatment in only 13.3% of knees. In 19.1% of knees, no surgical treatment was appropriate at the visit, based on the collected data.
Conclusion
Application of isolated radiologic criteria in patients with knee OA results in a UKA candidacy is misleadingly high. Appropriate Use Criteria that are based on both radiological and clinical criteria suggest UKA is appropriate in less than 15% of patients.
Knee
Osteoarthritis

### 20193 Development of antibiotic resistance in periprosthetic joint infection after total knee arthroplasty

Antonio Klasan1
Arne Schermuksnies2
Susanne Fuchs-Winkelmann2
Thomas J Heyse2
1Austria
2Germany
Summary
Resistance to new antibiotics is increasing.
Data
Aims: Management of periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) is challenging. Antibiotic management remains elusive due to differences in epidemiology and resistance between countries and reports. Before the efficacy of surgical treatment options is investigated, it is crucial to investigate the bacterial strains causing PJI, especially for cases where a culture could not be obtained.
Patients and Methods
A review of all revision TKAs between 2006 and 2018 in a tertiary referral center was performed. Included were cases meeting the consensus criteria for PJI, with identified cultures. Using a cluster analysis, 3 chronological time periods were created. We then evaluated antibiotic resistance of identified bacteria between these 3 clusters and the effectiveness of our antibiotic regime.
Results
We identified 129 PJI with 161 culture identified bacteria. Coagulase-negative Staphylococci (CNS) were diagnosed in 46.6% cultures, followed by Staphylococcus aureus in 19.8% of cultures. Overall antibiotic resistance (p=0.454) has not increased during the study period. CNS resistance to teicoplanin (p<0.001), fosfomycin (p=0.016) and tetracycline (p=0.014) has increased. Vancomycin had an 84.4% overall sensitivity and 100% CNS sensitivity and was the most effective agent.
Conclusion
Although we were unable to show an overall increase in antibiotic resistance in organisms that cause PJI after TKA during the study period, this was not true for CNS. It is concerning to note that when specifically looking at CNS resistance to new antibiotics, but not vancomycin, it has increased in little more than a decade. This study suggests that referral centres should continuously monitor obtained cultures as this has significant implications for both prophylactic treatment in primary as well as empirical antibiotic treatment in PJI.
Knee
Failed
Epidemiology

### 20156 Numbness around the replaced knee correlates with patient-reported outcome measures and kneeling

Masafumi Itoh
Umito Kuwashima
Junya Itou
Ken Okazaki
Japan
Summary
Numbness around replaced knee negatively correlated with patient-reported outcome measures .and affected kneeling. Knee replacements performed via an anteromedial incision may be at higher risk for numbness. Male sex, better knee flexion and less numbness were positively affected kneeling.
Data
Background
Numbness around a replaced knee is common but its effect on postoperative outcome is unclear. Joint awareness, an indicator of the integrity of replaced joints that correlates with patient satisfaction, might be affected by numbness. This study investigated the relation between numbness and patient-reported outcome measures (PROMs), including joint awareness and kneeling ability. We developed a Numbness score based on a 5-point Likert scale.
Methods
We retrospectively reviewed 404 patients (514 knees) underwent knee replacement at our institution between May 2007 and April 2019. PROMs, including the Numbness score, New Knee Society Score (KSS), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Forgotten Joint Score-12 (FJS-12), and other clinical and radiological data were collected from 311 patients (394 primary knee replacements) with complete data. Kneeling ability was evaluated using kneeling-specific items in KSS. Results Numbness score correlated with KSS-Symptoms (r=0.44) and KSS-Satisfaction (r=0.41), KOOS-Symptom (r=0.42), KOOS-Pain (r=0.44), KOOS-ADL (r=0.36), and KOOS-QOL (r=0.38), and FJS-12 (r=0.42). A multivariable regression analyses with the numbness score as the response variable suggested that the numbness score was better after midline incision than after anteromedial incision. A multivariable regression analyses with KSS-Kneeling as the response variable suggested that male sex, better postoperative knee flexion, and better numbness score were factors associated with better kneeling.
Conclusion
A worse Numbness score was correlated with inferior PROMs and affected inferior kneeling. Less numbness, male sex, and better knee flexion angle were positively associated with better kneeling.
Knee
Arthroplasty
Outcome Studies

### 19818 Treatment of bilateral hip femoroacetabular impingement: simultaneous or staged?

Gen Lin Foo1
Catherine J Bacon2
Matthew J Brick2
1Singapore
2New Zealand
Summary
Our study sets outs to assess the clinical outcome and complications rates between patients undergoing simultaneous versus staged surgery for bilateral hip femoroacetabular impingement.
Data
Introduction
Femoroacetabular impingement (FAI) typically involves both hips and presents a surgical dilemma when symptomatic at the same time. Bilateral simultaneous surgery can reduce the overall rehabilitation period compared to a staged surgery. However, the disadvantages are longer surgical time and possible higher complications. We hypothesize that there is no difference in the outcome and complication rates between bilateral simultaneous and staged surgery for FAI.
Methods
Patients who underwent simultaneous and staged bilateral primary hip arthroscopy for FAI between June 2005 and December 2018 were identified from our surgical database. Those who had their second surgery within 1 year of their index surgery were included in the staged group. The control group comprised patients who underwent a unilateral hip arthroscopy within the same time-frame. Patient Reported Outcome Measures (PROMs) including the 12-item International Hip Outcome Tool (iHOT-12), Non-Arthritic Hip (NAH) Total and Hip Disability and Osteoarthritis Outcome (HOOS) scores were collected pre-operatively and at regular intervals post-operatively up to 10 years. Two-year follow-ups scores were included in analysis if they were available, or later follow-ups if they were not. We also gathered data on complications and revision surgery rates including conversion to arthroplasty from a national registry.
Results
A total of 186 patients (372 hips) in the bilateral simultaneous and 83 patients (166 hips) in the bilateral staged were compared with 1275 patients in the unilateral group. The median duration between staged surgeries was 57 days (range 14 to 347 days). Simultaneous and staged surgeries did not differ in follow-up duration, patients’ age, gender, or body mass index, although patients in the unilateral group were older (37±12 years compared with 30±11 years in the bilateral groups; p<0.001). Two-year minimum post-operative scores in all 3 groups were significantly improved compared to their pre-operative scores (bilateral simultaneous iHOT-12 pre-op 37.0±18.7 and post-op 74.7±22.2; bilateral staged iHOT-12 pre-op 41.2±19.3 and post-op 69.4±25.6 and unilateral iHOT-12 pre-op 39.3±20.4 and post-op 75.3±23.4; p<0.001 for all changes). We found a significant difference in several 2-year minimum post-operative scores between the 3 groups after statistically adjusting for the differing pre-operative scores. Overall, the staged group performed worse in all scores (p<0.05 for all apart from HOOS Sports subscale and NAH Total scores). There was no difference in revision rates between groups, but simultaneous surgeries were less likely to undergo conversion to arthroplasty within the study’s 6.4±2.6 years follow-up duration (1.1% conversion rate for simultaneous, versus 3.6% in staged and 4.5% in unilateral; p=0.009).
Conclusion
Patient who underwent bilateral simultaneous hip arthroscopy for FAI did better in most PROM scores than staged surgery at the 2-year follow-up period, and were less likely within the study time-frame to require conversion to arthroplasty. These differences are likely due to selection for simultaneous versus staged procedures.
Hip/Groin/Thigh
Arthroscopy
Impingement
Labrum
Arthro-MRI
Bones
Cartilage
Cartilage Treatment
Femoroacetabular Impingement
Labrum Tears
Labrum Treatment
Physical Examination
X-ray

### 19923 High specialization among female youth soccer players is associated with an increased likelihood of serious injury: a cross-sectional study of youth, college, and professional soccer athletes

Michelle Xiao
Jacie L Lemos
Calvin E Hwang
Seth L Sherman
Marc R Safran
Geoffrey D Abrams
USA
Summary
High specialization in female youth soccer players is associated with an increased likelihood of sustaining a serious injury.
Data
Introduction
Sport specialization is increasingly common for youth athletes and can contribute to a higher likelihood of injury. Few studies have examined injuries as it relates to sport specialization in high-level female soccer players. The purpose of this study was to assess the associations between serious injury (> 3-month time loss) and level of specialization among high-level female soccer players and to compare the specialization and college commitment ages of female youth soccer players to Division I college and professional soccer athletes.
Methods
Youth, college, and professional female soccer players in the United States playing in the top league at each level were recruited to complete an anonymous online survey. The survey collected information about player demographics, soccer specialization and training patterns, history of serious injuries from soccer (defined as sidelining a player for three months or more), and perceptions surrounding soccer specialization. Descriptive summaries were presented for demographic data. Data from Division I and professional athletes were combined for analysis. Comparisons between groups were performed using 2-sample t-tests, chi-squared analyses, and binary logistic regression models controlling for differences in age. A p-value of less than 0.05 was set as significant.
Results
A total of 1,018 (767 youth, 251 college/professional) athletes completed the survey. Serious injuries affected 23.6% of youth and 51.4% of college/professional athletes. Anterior cruciate ligament (ACL) tears were the most common injury subgroup and were more prevalent in college/professional players compared to youth athletes (18.3% vs 4.0%; p < 0.001). Highly specialized youth athletes (66.5%) were more likely to have sustained a serious injury from soccer compared to athletes with low specialization (OR = 2.28 [1.38–3.92]; p=0.008) but not moderate specialization (OR = 1.37 [0.83–2.27]; p=0.43). Current youth soccer players started playing competitive soccer (7.4 + 2.2 vs 8.6 + 2.5 years; p < 0.001) and committed to play college soccer (15.3 + 1.6 vs 16.2 + 1.2 years; p < 0.001) at a younger age compared to college/professional athletes. A higher proportion of youth athletes specialized at a young age (< 10 years) compared to college/professional players (44.2% vs 25.9%; p < 0.001).
Conclusion
High specialization in female youth soccer players is associated with an increased likelihood of sustaining a serious injury. Current youth soccer players are specializing earlier and committing to play college soccer at a younger age compared to when current college and professional players did.
Orthopaedic Sports Medicine
Sport Specific Injuries
Epidemiology
Female Athletes
Gender Specific
Knee
Professional Athletes/Olympians
Sport Specific Population
Team Physician

### 19869 Predicting subsequent revision ACL reconstruction: a machine learning analysis of the norwegian knee ligament register

R Kyle Martin1
Solvejg Wastvedt1
Ayoosh Pareek1
Havard Visnes2
Gilbert Moatshe2
Julian Wolfson1
Lars Engebretsen2
1USA
2Norway
Summary
This machine learning analysis of a national knee ligament register can predict a patient’s risk of primary ACL reconstruction failure (defined as a subsequent revision surgery). The resulting algorithm supports the creation of an easy-to-use calculator for point-of-care risk stratification which can be used to guide surgical discussions with patients and quantify their specific risk of failure.
Data
Background
Several factors are associated with an increased risk of anterior cruciate ligament (ACL) reconstruction failure. However, due to the multiple patient, surgical, and rehabilitation factors that influence outcome, the ability to accurately translate these factors into a quantifiable risk of failure at a patient-specific level has remained elusive. Our hypothesis was that machine learning analysis of existing large national knee ligament registers has the potential to improve our predictive capability. The purpose of this study was to determine if machine learning analysis of primary ACL reconstructions in the Norwegian Knee Ligament Register (NKLR) can: (1) identify the most important risk factors associated with undergoing a subsequent revision ACL reconstruction, and (2) develop a clinically meaningful calculator for predicting the risk of requiring a revision operation.
Methods
Machine learning analysis was performed on the NKLR dataset. The primary outcome was probability of revision ACL reconstruction within 1, 2, and/or 5 years. Data was split randomly into training (75%) and test (25%) sets. Four machine learning models were tested: Cox Lasso, survival random forest, generalized additive model, and gradient boosted regression. Concordance and calibration were calculated for all four models.
Results
The dataset included 24,935 patients, and 4.9% underwent revision surgery during an average follow-up of 8.1 years (SD 4.1). All four models were well-calibrated, with moderate concordance (0.67–0.69). The Cox Lasso model required only five variables for outcome prediction: graft choice, femoral fixation device, KOOS QOL score at surgery, years from injury to surgery, and age at surgery. The other models either used more variables without an appreciable improvement in accuracy or had slightly lower accuracy overall. An in-clinic calculator was developed which can estimate the risk of graft failure (https://swastvedt.shinyapps.io/calculator_rev/). Whereas the overall risk of revision in the registry was 4.9%, this calculator can quantify risk at a patient-specific level.
Conclusions
Machine learning analysis of a national knee ligament register can predict the risk of a patient undergoing a subsequent revision ACL reconstruction after primary surgery with moderate accuracy. This algorithm supports the creation of an in-clinic calculator for point-of-care risk stratification prior to primary surgery based on the input of only five variables. Similar analysis using larger or more comprehensive data may improve the accuracy of risk prediction.
Knee
ACL
Ligaments
Repair/Reconstruction
Tears
Arthroscopy
Evidence Based Medicine
Failed
Instability
Outcome Studies
Professional Athletes/Olympians

### 19907 Relationship between posterior tibial slope and sagittal plane mechanics during jump landing after anterior cruciate ligament reconstruction

Robert A Duerr
Jennifer Perry
Robert A Magnussen
David C Flanigan
Benjamin Ormseth
Robert Siston
Andrew Garrone
Christopher C Kaeding
Laura C Schmitt
USA
Summary
Patients with elevated posterior tibial slope >=12 degrees have increased knee angular velocity during a double-leg landing task when compared to patients with posterior slope < 12 degrees.
Data
Objectives
Increased posterior tibial slope (PTS) has been identified as a risk factor for anterior cruciate ligament (ACL) injuries and ACL reconstruction failure. The relationship between PTS and sagittal plane knee biomechanics (such as knee angular velocity) has not been evaluated. Prior work has identified that higher knee angular velocities are associated with faster peak ACL strains, which may have implications on risk of ACL graft rupture. The purpose of this study was to evaluate the relationship between PTS and sagittal plane mechanics during jump landing in a cohort of patients after ACL reconstruction. It was hypothesized that sagittal plane landing mechanics would differ between those with PTS >= 12 degrees compared to those with PTS < 12 degrees.
Methods
A cohort of patients who underwent primary, unilateral ACL reconstruction at a single institution were identified in a prospectively collected ACL database. At 2-years post-ACL reconstruction a follow-up visit was conducted to collect biomechanics data and patient reported outcome scores, including Marx Activity Score, International Knee Documentation Committee (IKDC) Score, and Knee Injury and Osteoarthritis Outcome Score (KOOS). Three-dimensional motion analysis data were collected during the initial landing phase of a bilateral drop vertical jump task. Lateral posterior tibial slope (LPTS) was measured on lateral knee radiographs of the injured knee. Biomechanical variables of interest included ground reaction forces and sagittal plane knee kinematic and kinetic variables on the reconstructed limb. Pearson correlations were calculated to evaluate the association between LPTS and biomechanical variables of interest (a=0.05). The cohort was categorized based on LPTS into low slope (PTS < 12 degrees) and high slope (PTS >= 12 degrees) groups. Demographic, outcomes, and biomechanics data were compared between the groups with independent samples t-tests (a=0.05).
Results
A total 29 patients with lateral radiographs for LPTS measurements and complete biomechanics data were included (17 females) with a mean age of 22.3 years (range 17 to 35 years). There were no significant differences in age, body mass index, Marx activity score, IKDC Score, or KOOS subscales between the high slope and low slope groups. The mean LPTS was 13.4 ± 0.9 degrees and 8.7 ± 1.2 degrees in the high slope and low slope groups respectively. During landing, higher involved knee angular velocity was associated with higher LPTS (r=0.43, p=0.02). Individuals with high LPTS had significantly higher involved knee angular velocity compared to patients with low LPTS.
Conclusion
At 2 years post-ACL reconstruction, there were no differences in activity or patient reported outcome scores in those with high or low LPTS. During a double-leg landing task, high LPTS is associated with higher involved knee angular velocity. Further investigation of the associations among anatomic considerations (such as PTS), knee mechanics, and ACL graft strain are needed to identify patients at higher risk of graft rupture and inform post-operative rehabilitation and discussions regarding graft failure risk.
Knee
ACL
Instability
Ligaments
Repair/Reconstruction
Biomechanics
Exercise Physiology
Female Athletes
Rehabilition/Physical Therapy
Single Bundle
X-ray

### 19908 Relationship between body mass index and mid- to long-term patient outcomes after multi-ligamentous knee injury

Robert A Duerr
Danny Tan
Robert A Magnussen
Alex C Dibartola
Christopher C Kaeding
David C Flanigan
USA
Summary
Morbid obesity is associated with poorer mid- to long-term patient reported outcomes following surgical treatment of multiligament knee injuries compared to patients with BMI < 30 kg/m2.
Data
Objectives
Multi-ligamentous knee injuries (MLKI) can be debilitating and result in persistent functional limitations. These severe injuries are seen with increasing frequency in patients with elevated body mass index (BMI). The impact of elevated BMI on mid- to long-term outcomes after MLKI is not clear. We hypothesize that patients with elevated BMI demonstrate worse patient-reported outcome scores at mid- to long-term follow-up after surgical treatment of MLKI.
Methods
Records were reviewed to identify patients treated surgically for MLKI at a single institution between July 2005 and June 2018. Chart review was performed and patient demographics, injury information, and surgical data were collected. Patients were subsequently contacted and asked to complete a patient-reported outcomes assessment including the Tegner activity scale and Knee Injury and Osteoarthritis Outcome Score (KOOS). Patients were categorized by BMI into three categories based on Centers for Disease Control and Prevention (CDC) guidelines: normal/overweight (BMI < 30 kg/m2), obese (BMI from 30 to 39.9 kg/m2), and morbidly obese (BMI = 40 kg/m2). Patient-reported outcomes were compared among the three groups using ANOVA testing. Multiple linear regression analysis was used determine whether obesity or morbid obesity were associated with poorer patient-reported outcome scores compared to the BMI < 30 group, controlling for age at injury and mechanism of injury.
Results
A total 58 patients with 62 MLKI completed patient-reported outcomes scores at a mean follow-up of 8.1 years from surgery (range: 2.6 to 14.9 years). Mean age at the time of injury was 30.2 years (range: 17 to 63 years) and mean BMI at the time of injury was 30.3 kg/m2 (range 18.5 to 78.8 kg/m2). Overall patient reported outcome scores at follow-up were: Tegner: 4.8 ± 2.1, KOOS symptoms: 76.8 ± 17.3, KOOS pain: 82.3 ± 16.7, KOOS ADL: 87.7± 15.6, KOOS Sport 63.8 ± 30.2, and KOOS Knee QOL: 58.6 ± 25.6. Morbidly obese patients (BMI = 40 kg/m2) were noted to have lower KOOS scores than those with BMI < 30 kg/m2 (p < 0.05). Significantly lower Tegner score were noted in the morbidly obese group (2.1 ± 1.2) compared to the obese (5.1 ± 2.0) and BMI < 30 kg/m2 (5.2 ± 2.0) groups (p < 0.05). No significant differences in KOOS or Tegner scores were noted between obese patients (BMI from 30 to 39.9 kg/m2) and those with BMI < 30 kg/m2. Multiple linear regression demonstrated poorer patient-reported outcomes in the morbidly obese group compared to the BMI < 30 kg/m2 group (all p < 0.05), but no significant differences were noted between the obese group and the BMI < 30 kg/m2 group, controlling for patient age and mechanism of injury.
Conclusion
Morbid obesity is associated with poorer mid- to long-term patient-reported outcomes following surgical treatment of MKLI compared to patients with BMI < 30 kg/m2, controlling for age and mechanism of injury. Patients with BMI between 30 and 40 did not have poorer outcomes compared to patients with BMI < 30.
Knee
Ligaments
Posterolateral Corner
Repair/Reconstruction
Tears
Allograft
MRI
Outcome Studies
Physical Examination
Posterolateral
Sport Specific Injuries

### 20152 Radiological spine positioning on the tibial plateau and the implications for HTO planning

Wouter Van Genechten
Gino Mestach
Annemieke Van Haver
Jozef Michielsen
Peter Verdonk
Steven Claes
Belgium
Summary
RADIOLOGICAL SPINE POSITIONING ON THE TIBIAL PLATEAU AND THE IMPLICATIONS FOR HTO PLANNING
Data
Objective
The lateral tibial eminence has often been suggested as an appropriate target while aiming the weight bearing line (WBL) in valgus-producing high tibial osteotomy (HTO) procedures. The primary objective was to characterize the position of the medial and lateral tibial eminence on 2-D and 3-D imaging in the average HTO patient population. Secondly, the study evaluated the consistency in planned tibiofemoral alignment while aiming the WBL on the lateral eminence in HTO.
Methods
Tibial eminence positions originating from 70 HTO cases were retrospectively studied on preoperative full-leg standing radiographs and computed tomography (CT) scans. Eminence position was expressed as percentage of the width of the tibial plateau (medial border 0%, lateral border 100%). Osteophytes that could potentially enlarge the size of the tibial plateau were consciously excluded (PACS). 3-D models of the tibia were derived from the CT-scan in Mimics 23.0 and measurements were conducted in 3-matic 14.0 (Materialise, Leuven). Another 100 preoperative HTO full-leg standing radiographs were reviewed to evaluate consistency in tibiofemoral alignment during HTO planning. The tibial eminence positions (%), the mechanical femorotibial angle (mFTA°) and the mechanical medial proximal tibial angle (mMPTA°) were determined (mean±SD [range], PACS). After conducting the preoperative planning for each case with the WBL crossing the tip of the lateral eminence, the ‘planned’ mFTA and mMPTA were measured (Dugdale method). All measurements were conducted in two-fold by two blinded observers. The intraclass correlation coefficient (ICC) and the eminence imaging correlation statistics were performed in SPSS 26.0. RESULTS For the 70 HTO cases, the medial tibial eminence was located at 41.8%±1.9 [38–47%] in 2-D and 42.2%±2.0 [38–48%] in 3-D showing a high correlation (r=0.8271 (0.7349 to 0.8893)). The lateral tibial eminence was located at 58.3%±1.9 [55–63%] in 2-D and 57.3%±2.2 [53–63%] in 3-D showing a high correlation (r=0.7657 (0.6472 to 0.8481)). A good to excellent ICC (ranging 0.8346–0.9193) was observed. For the 100 HTO cases only measured in 2-D, the medial eminence was positioned at 42.1%±1.7 [38–47%], the lateral eminence at 58.5%±1.8 [54–65%], the preoperative mFTA was 173.8°±2.3 [167.8–177.5°], and mMPTA 85.8°±2.2 [81.5–91.2°]. While aiming the WBL on the lateral eminence, the planned mFTA was 181,8°±0.3 [181.2–182.5°] and the mMPTA was 93.8°±2.2 [89.2–100.7°]. The ICC was found to be good for the planned mFTA (0.804) and excellent for all other parameters (ranging 0.953–0.995).
Conclusion
Although frequently used as a target while planning corrections for HTO procedures, little is known about the exact position and variance of the lateral tibial eminence throughout the population. This study found that, in the average HTO patient, the medial and lateral eminences are located at respectively 42% and 57–58% on the tibia plateau with both showing a 10% maximal variance. Good agreement between the 2-D and 3-D imaging modalities was found while evaluating tibial eminence positions in the coronal plane. Furthermore, aiming the WBL through the lateral tibial eminence during HTO planning, will consistently produce 2° of valgus (±1°) mFTA. Meanwhile, the planned mMPTA remains highly dependent on the existing bony varus deformity of the tibia.
Knee
Bones
Cartilage
Osteoarthritis
Osteotomy
Biomechanics
Cartilage Treatment
CT-Scan
Elderly
Outcome Studies
X-ray

### 19776 Analysis of the blood supply to the femoral attachment of the anterior cruciate ligament after acl injury

Jedrzej Jerzy Lesman
Marcin E Domzalski
Krzysztof Nowak
Sebastian Zygmunt Zabierek
Ilona Wagner-Olszewska
Poland
Summary
Age above 38 years and 9 months from complete rupture of the ACL cause lower blood supply and lower bone quality of subchondral bone.
Data
Anterior cruciate ligament injury is one of the most common knee injuries occurring in both professional athletes and amateurs. The actual knowledge does not take under the consideration the effects on the femoral bone after the rupture. Therefore, a group of researchers from Medical University of Lódz decided to perform the research. The aim of the study was to assess bone quality and the degree of blood supply to the femoral attachment of the anterior cruciate ligament on the femur. The study involved mature patients diagnosed with ACL rupture. Before the procedure, the researchers obtained data from the patients regarding: gender, age, time from injury to surgery, smoking cigarettes and the level of the patient‘s activity after injury. During the cruciate ligament reconstruction surgery in patients, before drilling the femoral canal, a 4.5 mm bone block with a diameter of 3.5 mm and a length of 2 cm on average was collected using Synthes® Hollow Reamer. A block meeting the test criteria was collected in 50 patients. The block was subjected to decalcification, then it was divided into 3 equal blocks. A cross-section was made of each block, which was fixed in hematoxylin and eosin, as well as an immunohistochemical test for cells with the presence of CD34. The number of blood vessels and clusters of positive cells for CD34 per mm2 was counted using ImageJ ™. Bone tissue quality was also analyzed by counting the average and total number of tissue windows left by osteocytes. Finally the statistical analysis was performed. The median waiting time for surgery was 9.5 months. Patients who had undergone surgery before 9 months showed an average number of 5 blood vessels per mm2 cross-section, while in patients who waited longer for the procedure the number was 2 vessels, a statistically significant difference (p <0.01). Similar statistical significance was observed when examining the number of clusters of cells stained with CD34 marker, on average 5 clusters in the group up to 9 months after injury, less than 3 in the group waiting longer for surgery. Bone quality deterioration is also reflected in the time of waiting for surgery - the first group average osteocyte density per mm2 is 74, the second group 54 (p <0.01). A statistically significant interaction was also observed between age and time from injury - where, firstly, there was a negative correlation of time from injury to vessel density, and secondly, the relationship would be stronger among people up to 38 years of age. than in people over 38 years (r = −0.659; p <0.001; over 38 years r = −0.523; p = 0.018) (figure 2). The analyzes did not reveal the interactive relationship between sex and time from injury. In summary, the waiting time for surgery has a significant impact on the blood supply and bone quality of the ACL attachment site. Age above 38 years and 9 months from complete rupture of the ligament may cause a longer healing period of the graft.
Knee
ACL
Ligaments
Repair/Reconstruction
Tears

### 19778 Arthroscopic bankart repair for adolescent anterior shoulder instability: clinical and radiographic predictors of revision surgery and subjective instability

Crystal A Perkins
Anthony Egger
Michael T Busch
Sam Broida
Samuel C Willimon
USA
Summary
HSI >/= 15 mm was associated with a 50% failure rate following adolescent arthroscopic bankart repair, yet off-track lesions were not predictive of failure.
Data
Introduction
The treatment of adolescent shoulder instability can be a challenging problem, with multiple patient and radiographic risk factors for recurrent instability. Although glenoid bone loss has been well described, humeral bone loss has gained more recent attention, particularly with respect to “off-track” lesions. The purpose of this study is to evaluate clinical and radiographic predictors of failure following arthroscopic bankart repair in adolescents.
Methods
A retrospective IRB approved study was performed to identify patients less than 19 years of age treated with isolated arthroscopic anterior labral repair for unidirectional shoulder instability. Radiographic measurements of glenoid diameter,% glenoid bone loss, glenoid track, Hill-Sachs interval (HSI), HS/glenoid track (HS/GT) ratio, and hill-sachs depth were performed for all patients with magnetic resonance imaging (MRI). All patients were contacted at final follow-up to collect outcome scores (PASS and SANE scores, activity level). All patients had minimum 24-month follow-up. Failure was defined as revision surgery or post-operative subjective instability.
Results
59 patients, 46 males and 13 females with a median age of 16 years [15, 17] were included. 10 patients (17%) had revision surgery and 8 patients (14%) had subjective instability without revision. In univariate analysis, patient height was the only patient factor which was significantly different between the revision/instability (RI) cohort and the non-revision/instability (NRI) cohort. Intra- and inter-rater reliability (ICCs) for radiographic measurements were good to excellent for all measurements. The only radiographic variable which was statistically significantly different between the RI and NRI cohorts was glenoid diameter. Percent glenoid bone loss, glenoid track, HSI, and HS/GT ratio, were no different. 5 patients measured ”off track” with a HSI:GT >1, but this was not associated with RI. Subgroup analysis of 38 patients with a hill-sachs defect identified significantly greater HSI and HS depth in the revision surgery cohort (20.9 mm, 6.8 mm respectively) as compared to no revision (13.9 mm, 5.0 mm respectively), (p=0.001, p=0.031 respectively). Among patients with a HSI >/= 15 mm, there was a 50% rate of revision surgery. Patient reported outcome measures were obtained in all patients PASS and SANE scores at final follow-up were significantly lower in the RI cohort (75.5 and 67.5, respectively) as compared to the NRI cohort (98 and 98 respectively), p<0.001. 74% of NRI patients returned to the same or higher level of sport following surgery, as compared to 56% of RI patients, but this did not reach statistical significance (p=0.225).
Conclusions
31% of adolescent patients in our cohort had revision instability surgery or reported subjective feelings of instability following arthroscopic bankart repair. This was associated with inferior PASS and SANE scores and lower rates of return to sports. Off-track lesions, as measured by HS/GT ratio, were identified in 8.5% of our cohort, but were not predictive of failure with primary bankart repair. Among patients with a HS defect, greater HSI and HS depth was associated with revision surgery. This study includes the highest risk patient population for recurrent instability based on prior studies – male, adolescent, contact sport athlete – and this likely is a confounding factor in identifying additional clinical and radiographic predictors of failure. In our adolescent series, the current definition of “off-track” does not appear to reliably predict failure with isolated bankart repair.
Shoulder
Glenohumeral
Instability
Repair/Reconstruction
Arthroscopy
Labrum
MRI
Outcome Studies
Sport Specific Injuries
Sport Specific Population
X-ray

### 20144 Intra-articular mesenchymal stem cell exosomes and hyaluronic acid combination therapy promotes safe and functional osteochondral repair in a porcine model

Keng Lin Wong
Shipin Zhang
Xiafei Ren
Ruenn Chai Lai
Sai Kiang Lim
James Hui
Wei Seong Toh
Singapore
Summary
Mesenchymal stem cell exosomes and hyaluronic acid combination administered at a clinically acceptable frequency of three intra-articular injections promote osteochondral repair with significantly improved morphological, histological, and biomechanical outcomes in a clinically relevant porcine model.
Data
Purpose
We had previously reported the efficacy of human mesenchymal stem cell (MSC) exosomes in repair of critical-size osteochondral defects in rats and rabbits. To enable clinical translation of MSC exosomes, we proposed a validation of the efficacy of MSC exosomes in a large animal model.
Materials & Methods
Bilateral osteochondral defects (6 mm diameter and 1 mm depth) were surgically created on the medial femoral condyles of 24 knees in 12 micropigs. Immediately after surgery and at days 8 and 15 post-surgery, 6 micropigs in exosome/HA group received sequential administration of 1mg exosomes in 1ml phosphate-buffered saline (PBS) followed by 1ml hyaluronic acid (HA; Synvisc®) in both knees, whereas the other 6 micropigs in the HA group received 1ml of PBS followed by 1ml HA in both knees. Except for MRI performed on day 15, 2 and 4 months, macroscopic, histological, biomechanical, and micro-CT assessments were performed at 4 months.
Results
At 4 months, exosome/HA-treated defects had significantly higher MRI scores than that for HA-treated defects at day 15 (4.46 vs 3.63; P=0.017), 2 months (7.83 vs 5.79; P=0.023) and 4 months (9.25 vs 6.71; P=0.024). Exosome/HA-treated defects also had significantly better ICRS macroscopic score (9.22 vs 7.25; P=0.008) and ICRS II histological score (79.71 vs 65.10; P=0.032) than HA-treated defects. The mean Young’s moduli of exosome/HA-treated defects were higher than that of HA-treated defects in the defect periphery (19.92 vs 5.50MPa; P=0.003) but modestly in the defect centre (15.17 vs 3.53MPa; P=0.119). Micro-CT analysis revealed structural improvements in the subchondral bone with significantly higher BV/TV and Tb.Th in exosome/HA-treated defects than in HA-treated defects. Importantly, no adverse responses or systemic alterations were observed.
Conclusion
MSC exosomes and HA combination administered at a clinically acceptable frequency of three intra-articular injections promote osteochondral repair with significantly improved morphological, histological, and biomechanical outcomes in a clinically relevant porcine model.
Knee
Biologics
Cartilage
Osteoarthritis
Stem Cell Therapy
Basic Science
Cartilage Injuries
MRI

### 20129 Contralateral versus ipsilateral quadriceps graft, for anterior cruciate ligament reconstruction

Franco Della Vedova
Hernan Galan
Daniel A Slullitel
Argentina
Summary
One of the most common complications in anterior cruciate ligament reconstructions is high donor site morbidity. We propose that contralateral quadriceps graft could be a reasonable option especially in patients that have poor tolerance to pain and need to return to work sooner.
Data
Introduction
One of the most common complications in anterior cruciate ligament reconstructions is high donor site morbidity and postoperative pain, which is often associated with difficulties in the restoration of motion and delayed return to daily activities. The objective of this paper is to compare postoperative pain, time to return to daily activities, and other clinical outcomes, in two groups of patients undergoing primary ACL reconstructions with autologous bone-quadriceps tendon (BQT) graft from the ipsilateral or contralateral knee. We propose that contralateral BQT could be a reasonable option especially in patients that have poor tolerance to pain and need to return to work sooner.
Methods
Patients with primary ACL reconstruction using autogenous BQT graft were non-randomized and prospectively evaluated. Patients were given the choice of where to obtain the graft from, either from the ipsilateral knee (injured) or from the contralateral knee (healthy). It was explained to the patients that, according to our experience, patients operated on with contralateral knee graft suffered less pain in the immediate postoperative period, because the surgical trauma was divided between the two knees and that they could have a sooner return to daily activities or light work. It was also explained to the patients that, as a disadvantage, a totally healthy knee was being operated on, with possible surgical complications. The inclusion criteria were isolated ACL tears, less than one year from injury to surgery, use of an autologous quadriceps tendon graft, and correct follow-up. Patients with associated ligament injuries, meniscal repairs, Outerbridge II or higher osteochondral injuries, patellofemoral pathology, and revision surgeries were excluded. We evaluated postoperative pain, the amount of analgesics consumed, time to full range of motion, and time to return to activities of daily living and sport activities.
Results
Seventy-eight patients with primary ACL reconstruction using autogenous BQT graft were prospectively evaluated. In 34 patients (Group A) the graft was obtained from the ipsilateral knee, in the others 44 patients (Group B) the graft was obtained from the contralateral knee. Patients in Group B had less postoperative pain than Group A (1,8 ± 0,6 - 3,1 ± 0,6 - p < 0,0001) consumed less amount of pain medication (p<0,0001), and re-established flexion and extension faster than those with ipsilateral graft harvest (P < 0,0001). Group B patients also returned earlier to their daily activities (26.5 ± 15.3 days) than those in Group A (37 ± 11.42 days) (p < 0.0001). Patients in group B return to work sooner than group A (Graph 3). There was no difference in time to return to sport.
Conclusions
Patients operated with contralateral quadriceps tendon graft have less postoperative pain, achieve earlier full mobility, consume less pain medication post-operatively, and return faster to activities of daily living and work than those undergoing ipsilateral graft harvest. We think contralateral harvest of BQT graft is an excellent choice especially for patients who have poor pain tolerance and in those in which a quicker return to their activities of daily living or work is a priority.
Knee
ACL
Autograft
Instability
Ligaments
Outcome Studies
Sport Specific Population

### 19848 Type Iv and V acromioclavicular dislocation: long terms results of conservative treatment in rugby players

Franco Della Vedova
Matias Orlando
Hernan Galan
Daniel A Slullitel
Argentina
Summary
High-grade acromioclavicular dislocation is a frequent injury in rugby players. Even though surgical treatment of Type IV and V, is the treatment of choice, we think that conservative treatment could be a reasonable option in this kind of collision athletes.
Data
Introduction
There is a consensus that surgical treatment is the treatment of choice of Type IV and V acromioclavicular dislocations (ACD). When it comes to the treatment of high-grade ACD in rugby players, however, we believe that this pathology could be handled from a different perspective, as return-to-play is these patients‘ main concern and aesthetic deformities do not usually present a problem for them. On the other hand, collision athletes are exposed to a high risk of recurrence. The objective of this study is to report the long-term results of conservative treatment of grade IV and V acromioclavicular dislocation in a group of rugby players.
Methods
We retrospectively evaluated nonoperatively treated male rugby players with grade IV and V ACD at a minimum of a five-year follow-up. All patients were evaluated by the UCLA and Constant scores, and the visual analogue scale of pain (VAS) from 0 to 10, as well as the satisfaction degree from 0 to 10, were obtained. Return-to-sport time and whether the patient received local corticosteroids injections were also documented. Possible comorbidities such as pain for daily activities, cosmetic discomfort, mobility deficit, and any limitations concerning recreational sports activities were additionally recorded. A comparative Zanca view X-ray was performed for all patients.
Results
There were 87 patients, 72 (82,75%) with type V AC joint dislocation and 15 (17,25%) with type IV. The average age at the time of injury was 24.2 years (14 - 37) and the average follow-up time was 13.8 years (5 - 23). The return to sports time was 3,8 weeks (1 - 12), the average return-to-play time for the patients that received a cortisone injection was 2,1 weeks (1–9), whereas for the no injection group it was 4,9 weeks (2–12). Of the 87 patients, 49 (56.32%) reported no pain for daily activities, 33 patients (37.5%) had some minor pain or discomfort, 5 patients (5.74%) continued to experience moderate pain, and no patients presented with severe pain. The visual analogue scale average was 2.2 points (0 - 5). Regarding aesthetic discomfort, only 4 patients (4.59%) experienced significant discomfort, 29 (33.33%) manifested less discomfort, and the remaining 54 patients (62%) did not present any aesthetic discomfort. The result of the UCLA score was 31,3 points (28 - 35), Constant score average was 88,2 points (68–100) and the VAS was 2,2 (0–5), The average separation in the Zanca View X-ray was 198% (106–309%). Only 3 patients (3,45%) underwent surgery in the chronic face due to bad results. The degree of satisfaction was 7.8 points (5-10) and no patient regretted not undergoing surgery.
Conclusions
Rugby players with type IV and V ACD, have good long-term functional results with conservative treatment. We believe that it is an acceptable therapeutic option in this type of patients as it allows for an almost immediate return to play and, in case of failure, these patients can still undergo an anatomical reconstruction in a delayed form
Shoulder
Acromio Clavicular
Dislocation
Capsuloligamentous Complex
Outcome Studies
Physical Examination
Sport Specific Injuries
Sport Specific Population
Team Physician
X-ray

### 19997 Combining sensor and robotic technologies to balance total knee arthroplasties

Julien Bardou-Jacquet
Jérôme Murgier
François Laudet
France
Summary
The primary objective of this study was to demonstrate the ability to achieve a quantitatively balanced knee by combining robotic arm (MAKO, Stryker, Kalamazoo, Michigan, USA) and intra-operative load sensors (Verasense, Orthosensor, Inc, Dania Beach, Florida, USA), while avoiding any soft tissue corrections.
Data
Knee
Arthritis
Arthroplasty
Cartilage
Elderly

### 20072 A new posterior triceps approach for total elbow arthroplasty in patients with osteoarthritis secondary to fracture: clinical experience

Andrea Celli
Italy
Summary
We describe a novel triceps exposure approach for TEA, the anconeus-triceps lateral flap, which has proved valuable in patients with distal humeral and olecranon fractures malunion, and its preliminary results at a minimum follow-up of 24 months.
Data
Aim
We describe a novel triceps exposure approach for TEA, the anconeus-triceps lateral flap, which has proved valuable in patients with distal humeral and olecranon fractures malunion, and its preliminary results at a minimum follow-up of 24 months.
Background
Over the past decade, total elbow arthroplasty (TEA) procedures have increased due to an increase in the number of trauma patients. Most current posterior approaches to the elbow provide excellent joint exposure, but involve the risk of extensor mechanism injury and eventual insufficiency, particularly in patients with osteoarthritis (OA) secondary to fracture.
Methods
Twenty consecutive patients with OA due to distal humeral and olecranon fractures malunion underwent TEA by the anconeus-triceps lateral flap approach, which preserves the olecranon insertion of the medial portion of the triceps proper tendon.
Results
At a mean follow-up of 33 months, the mean Mayo Elbow Performance Score rose from 41.3 to 94.3. The mean score of the visual analog scale for pain fell from 7.1 to 1.1. There were no patients with insufficiency or secondary detachment of the triceps tendon reporting grade 4 to 5 of the Medical Research Council scale. Discussion: These preliminary data suggest that preservation of the insertion of the medial portion of the triceps proper tendon enables earlier active rehabilitation. Moreover, the new approach provides optimum exposure of the olecranon also in patients with OA secondary to intra-articular fracture of the distal humerus and olecranon, where scarring and bone deformity usually hamper joint exposure.
Conclusion
The present preliminary data suggest that preservation of the medial portion of the triceps tendon insertion in patients undergoing TEA for OA secondary to fracture: i) reduces the risk of triceps insufficiency and enables early active rehabilitation; ii) affords optimum surgical exposure of the olecranon articular surface, especially in elbows with severe fracture malunion, like the patients described here; iii) and allows adequate alignment of the olecranon and the posterior ulnar surface without the interposition of the entire triceps muscle-tendon unit between the planes, since the relationship between them is a key landmark for ulnar component positioning.
Elbow/Wrist/Hand
Joints
Osteoarthritis
Total Joint Replacement
Ostheoarthritis
Outcome Studies
Physical Examination

### 20074 Clinical results of the bipolar radial head replacement in acute and chronic lesions observed in large group of the patients

Andrea Celli
Italy
Summary
The aims are to analyse the advantages and disadvantages of this design and to evaluate the types and clinical aspects of the complications observed.
Data
Introduction
The radial head prosthesis are useful for restoring the elbow and forearm stability when the radial head is unreparable in acute and chronic lesions. Little information with small series of patients have been reported in the literature on the bipolar radial head design used in acute and chronic elbow lesions. The propose of the current study is to report the results obtained in large series of the patients treated using the bipolar design for acute and chronic elbow lesions.
Materials and Methods
We performed in our Institution between 2000 to the end of 2009, 95. implants of bipolar radial head prosthesis. 70 consecutive patients were followed up with a minimum of 24 months,39 implant were used in acute elbow lesions and 31 for chronic post-traumatic lesions. All the surgical procedures were performed using the same bipolar prosthesis. All the patients underwent clinical an radiographic evaluations. The clinical data were collected and analysed using the Mayo elbow performance score and the Dash score and the patient’s satisfactions, The radiographic evaluations were performed in static view (antero-posterior and lateral views) and in dynamic way using the fluoroscopy evaluations. The complications were divided in two groups, involving the prosthesis or the elbow joint to better understand the disadvantage of this prosthesis design.
Results
70 patients (47 males and 23 females, mean age 44.5 years) were followed up with mean time of 39.1 months According to MEPS, in the acute group we obtained 32 excellent results and 2 goods, one fair, four poor, in chronic group the excellent result were observed in 22 patients, four good, one fair and four poor. According to Dash in the acute lesions we observed at the last follow-up a mean value of 11.6 points (range from 0 to 62.5), in the chronic lesion the mean value was 8.5 points (range from 0 to 35.3). The complications observed correlated to the implant design were found in 6 patients (31.6% of all the complications), 68.4% of complications were correlated to the joint and not to the implant.
Discussion and Conclusion
From our experience, the bipolar design obtain significant advantage in the treatment chronic elbow lesion in particular if associated to the ulna fracture that involve the less sigmoid notch. The bipolar design can adapt itself to the anatomic variability of the elbow and can compensate the malreduction of the radial sigmoid notch, this consideration was confirmed by our results.
Elbow/Wrist/Hand
Implant
Joints
Trauma
Ostheoarthritis
Outcome Studies
Physical Examination

### 20242 Choice of distalising tibial tubercle osteotomy does not significantly affect risk of tibial shaft fracture at time zero: a composite saw bone and finite element analysis (FEA) study

Alexander S Nicholls
Samuel Grasso
Tegan Cheng
Myles RJ Coolican
David Little
Australia
Summary
Choice of distalising tibial tubercle osteotomy does not significantly affect risk of tibial shaft fracture (at time zero)
Data
Introduction
Tibial tubercle osteotomy (TTO) is a commonly used surgical treatment for patients with recurrent patellofemoral instability. The presence of significant patella alta is an indication for distalisation of the tibial tubercle and this necessitates a cut in the anterior cortex of the tibia. This causes a weakness in the tibia which may result in the rare complication of tibial shaft fracture during the perioperative period. A step cut is thought to cause the greatest stress riser. Our hypothesis was that a step cut at the distal end of a TTO would cause a greater stress riser than a bevelled cut at time zero. METHODS Composite saw bones with cortical and cancellous components which are mechanically validated against human bones were used. Three types of osteotomy were performed using 3D-printed cutting jigs (step cut, bevelled cut and “V” cut; n = 4 per group) and compared to a control group with no osteotomy (n = 4). Tibia were stressed to the point of fracture using a 4-point bending technique in a 10 kiloNewton Instron machine. Mechanical data was then entered into an FEA model for further analysis.
Results
Mean differances between groups were as follows: control vs step cut 2935 N (95% CI 1113–4758; p = 0.0022), control vs V cut 3752 (95% CI 1929–5574, p = 0.0003), control vs taper cut 4050 N (95% CI 2228–5873; p = 0.0001), V cut vs step cut −816 (95% CI −2639–1006; p = 0.56), V cut vs taper cut 298 N (95% CI - 1524–2121; p = 0.96), step cut vs taper cut 1115 N (-707–2937; p = 0.31).
Conclusion
All types of TTO were associated with increased tibial shaft fracture risk at time zero (mean 39.6% reduction in tibia strength versus control group). Contrary to our hypothesis, TTO with distal step cut was not associated with an increased fracture risk. Consequently, bevelled and “v-shaped” cuts were not associated with reduced fracture risk. All data is tested at time zero and does not account for duration of healing or fixation used in vivo. Despite using symmetrical lab-tested saw bone models there was variation in loads to failure in each group.
Knee
Instability
Osteotomy
Patellofemoral
Basic Science
Biomechanics
Bones
Recurrent Subluxation and Dislocation
Sport Specific Population

### 20268 Return to sports after paediatric anterior cruciate ligament reconstruction (ACLR): normal population Vs An ACLR cohort

Alexander S Nicholls1
Jillian Lee2
Yoong Lim1
Quang Dao1
1Australia
2New Zealand
Summary
12 months after ACLR, most children demonstrate significant deconditioning on their uninjured leg relative to a normative population
Data
Introduction
Return to sport (RTS) functional testing post-ACLR relies on the comparison against the healthy limb (with >90% performance considered satisfactory). Limited normative paediatric population data exists. In addition, the effect of leg dominance in this population is unknown. We hypothesised that the normal limb (uninjured limb) in paediatric patients 12 months post-ACLR would differ from the normal population values, in functional RTS testing. In addition, we hypothesized that limb dominance would account for significantly better functional scores which may account for misleading RTS results post surgery.
Methods
87 healthy children (mean age 14 years 8 months) were recruited from local schools and community sports clubs. This normative group underwent routine RTS functional testing to gain control values. 87 post-ACLR children (matched for age, height, weight and Tegner activity level) underwent RTS functional testing in our research institute. Study participants in both groups carried out the following functional tests: knee range of motion, hamstring strength, quadriceps strength, hop for distance, hop for height and cross-over hop. Differences between the normal (uninjured) limb of the post-ACLR group and the normal healthy group were highlighted. The effect of leg dominance on RTS testing performance was also assessed within the normal group. RESULTS The normal limb of the post-ACLR group performed significantly worse than the normal (control) population in all functional testing results hamstring strength (control, 85.33±42.84 Nm; non-injured ACLR, 52.3±45.23 Nm; p=0.0001), quadriceps strength (control, 183.6±75.6 Nm; non-injured ACLR, 143.16±115.98 Nm; p=0.02), hop for distance (control, 86.52±28.19 cm; non-injured ACLR, 61.84±25.6 cm; p=0.0001) and hop for height (control, 24.8±7.15 cm; non-injured ACLR, 21.76±7.48cm; p=0.0001). Leg dominance in the normal population significantly positively effects quads strength (4% higher in dominant limb; dominant, 315.1±99.4Nm; non-dominant, 302.9±92.2Nm; p=0.006), triple hop (3% higher in dominant limb; dominant, 434.2±88.1cm; non-dominant, 423.2±87.0cm; p=0.006) and hop height (7% higher in dominant limb; dominant, 23.8±8.8cm; non-dominant, 22.2±7.9cm; p=0.01), but has no significant effect on other tests.
Conclusion
RTS functional testing at 12 months post-ACLR demonstrates deconditioning in the normal limb relative to a healthy age-matched paediatric population. This may imply contralateral injury risk and consideration should be given to longer rehabilitation periods. The effect of limb dominance in the paediatric population does not significantly affect outcome of RTS testing. Hence, limb dominance is unlikely to cause false positives or false negatives in the RTS testing.
Knee
ACL
Instability
Ligaments
Repair/Reconstruction
Basic Science
Biomechanics
Exercise Physiology
Rehabilition/Physical Therapy
Sport Specific Population

### 20254 Role of human amniotic membrane and PRF membrane in achilles tendon repair: A comparative clinico – radiological study

Amit Lakhani
Ena Sharma
India
Summary
Achillies tendon repair with Human Amniotic membrane Vs Platelet rich fibrin
Data
Introduction
The Achilles tendon is the largest and most powerful tendon of human body. Despite being the thickest tendon in human body it is one of the common tendon to get rupture. Rerupture is one of the most frequent complications reported after TA tendon repair. Hypocellularity and hypovasularity are reasons for weaker construction after TA repair. Augmentation has been used in tendon repair to strengthen the repair site and reduce the risk of rerupture. Human Amniotic membrane(HAM) and PRF (platelate rich fibrin) can be used to augment tendon during repair. The human amniotic membrane is a bilayer translucent membrane fixed to the fetal surface of the placenta. This membrane is rich in cytokines. Helps in Promotion of Epithelialization, Inhibition of Fibrosis, Inhibition of Inflammation and Angiogenesis, Lack of Immunogenicity, Antimicrobial and Antiviral Properties Based on these properties and its unique structure makes it an ideal biomaterial and PRF membrane is autologous and It has a natural fibrin framework with growth factors within that may keep their activity for a relatively longer period and stimulate tissue regeneration effectively and Act as a potential scaffold and it seems to enhance cellular proliferation and differentiation, augmenting angiogenesis, acting as a matrix for tissue growth. Material and methods- we included 30 patients with Achillies tendon rupture and divided into two random groups 15 each. in one group HAM was used for augmentation and in other group PRF membrane was used. With the patient prone, make a posteromedial incision approximately 10 cm long about 1 cm medial to the tendon and ending proximal to where the shoe counter strikes the heel. Approximate the ruptured ends of the tendon with a 2-0 nonabsorbable suture and wrap the membrane around the stitched site. Close the paratenon and skin. At 2 weeks, the cast is removed, the wound is inspected.
Results
The assessment included evidence of infection and pain graded by the visual analog scale recorded at preoperatively, postoperative 2 and 6weeks, 3 months and 6months,12 months and 18 months At each visit, the range of motion (Thompson test, Rest angle and Calf Circumfrence) Pinch test strength was compared with contralateral side Healing evaluation with high-frequency ultrasound (HFUSG) The parameters: (a) maximum thickness at the repair site; (b) proximal thickness of the normal tendon measured 8 mm proximal to the maximum thickness of the repair site. Biologic response evaluation with inflammatory mediators serum levels of IL-6 and TGF-ß1 in patients Though both membranes are equally effective in providing clinically significant outcomes with respect to VAS score, Pinch test, Biological evaluation of IL-6 and TGF-ß1 in all patients but HAM showed more stable results in consensus with higher total active range of motion, and better tendon glide on ultrasonography at follow-up (6–18 months). The levels of serum inflammatory biologic markers decreased in majority of HAM cases as compare to PRF. No infection/immune rejection phenomenon was seen in both groups.
Ankle/Foot/Calf
Biologics
Tears
Tendon
Achilles Tendon Injury
MRI
Repair/Reconstruction
Sport Specific Injuries

### 19902 Uncemented tantalum metal components versus cemented tibial components in total knee arthroplasty: 11- to 15-year outcomes of a single-blinded randomized controlled trial

Matthew Hampton
Junaid Mansoor
Paul M Sutton
UK
Summary
The use of an uncemented trabecular metal tibial implant can afford better long-term clinical and radiographic outcomes when compared to cemented tibial components of a matched design.
Data
Introduction
Total knee arthroplasty is an established treatment for knee osteoarthritis with excellent long-term results, but there remains controversy about the role of uncemented prostheses. We present the long-term results of a randomized trail comparing uncemented tantalum metal tibial components with conventional cemented components of the same implant design.
Materials and Methods
90 Patients of 70 years or less with symptomatic osteoarthritis of the knee were randomized to receive either an uncemented tantalum metal tibial monoblock component or a standard cemented modular component. The same cruciate retaining total knee system was used in both groups. All patients received an uncemented femoral component and no patients had their patella resurfaced. Patient outcomes were assessed preoperatively and postoperatively using the modified Oxford Knee score, Knee Society score, and 12-Item Short-Form Health Survey questionnaire (SFS-12) score. Radiographs were analysed using the American Knee Society Radiograph Evaluation score. Operative complications, reoperations or revision surgery were recorded.
Results
The mean patient age at time of recruitment to the study was 63 years (50-70), 46 (51.1%) knees were in male patients and the mean BMI was 30.4 (21-36). At last review, all patients were between 11 and 15-years following surgery, 11 had died and 2 were lost to follow-up. Of the remaining patients 41 of the knees were cemented and 36 uncemented. There were no revisions in the cemented group and one revision in the uncemented group for fracture. At long term follow-up the uncemented group reported better improvements in Oxford and Knee Society scores compared with the cemented group. These improvements were statistically and clinically significant (p = 0.001). The global (SF-12) scores demonstrated no statistical difference (P=0.81). Uncemented knees had better radiological analysis compared with the cemented group (p < 0.001)
Conclusion
Use of an uncemented trabecular metal tibial implant can afford better long-term clinical outcomes when compared to cemented tibial components of a matched design. However, both have excellent survivorship up to 15 years after implantation.
Knee
Arthritis
Arthroplasty
Evidence Based Medicine
Implant
Outcome Studies
Total Joint Replacement

### 19970 Comparison of outcomes in total knee arthroplasty performed with patient specific instrumentation vis-á-vis conventional instrumentation; a randomised control study

Saqib Yasin
India
Summary
PSI is better in terms of achieving neutral mechanical alignment much more consistently than conventional instrumentation.
Data
Background
The primary objective of this randomised control study was to compare the surgical aspects, radiological parameters and clinical outcomes of total knee joint arthroplasty performed with patient specific instrumentation and compare it with surgeries done using conventional instruments.
Methods
A total of 100 patients were randomly enrolled into the study and divided into two groups each. All patients underwent unilateral total knee arthroplasty. One group numbering 50 underwent surgery using Patient Specific Instruments(PSI Group) and the other group comprising 50 patients underwent surgery with conventional methods (CI Group). Each patient in the PSI Group underwent CT Scan of the knee to be operated for fabrication of Cutting Guides. All patients underwent weight bearing full length lower limb x-rays before and after surgery in order to measure and compare mechanical alignment that is Hip-Knee-Ankle (HKA) angles. All surgeries were performed using Stryker Scorpio° NRG PS design implants. Blood loss and time of surgery between the two groups were measured intra-operatively. Functional outcomes were measured using The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scoring system at 6 weeks and 6 months.
Results
There was statistically significant difference in the mean post-operative mechanical alignment achieved between the two groups (p=0.041). Moreover, the percentage of Outliers (defined as HKA angle of more or less than 180±3°) was significantly much more in the CI Group (p=0.007). Amount of blood loss during surgery was significantly less in PSI Group as compared to the other as was the duration of surgery(p<0.001). The technique demonstrated a very high degree of accuracy as far as predictability of implant size is concerned. However, no statistically significant difference in functional outcomes was found between the two groups.
Conclusion
PSI is better in terms of achieving neutral mechanical alignment much more consistently than conventional instrumentation. The technique provides additional advantages of lesser blood loss, decreases surgical time and improves predictability of implant sizes. The technique has no impact on clinical outcomes at least in the short term
Knee
Arthroplasty
Cartilage
Osteoarthritis
Arthritis
Biomechanics
CT-Scan
Elderly
X-ray

### 20008 Does in vivo kinematics following acl reconstruction with or without lateral extraarticular tenodesis correlate with preoperative quantitative pivot shift?

Christopher M Gibbs1
Philipp Wilhelm Winkler2
Jonathan D Hughes1
Daisuke Chiba3
Bryson P Lesniak1
William Anderst1
Volker Musahl1
1USA
2Germany
3Japan
Summary
Preoperative quantitative pivot shift does not correlate with postoperative knee kinematics using a high-resolution in vivo analysis system.
Data
Introduction
Following anterior cruciate ligament (ACL) injury, quantitative pivot shift (QPS) testing using the PIVOT technology can detect high- and low-grade rotatory instability.(1,2) Previously, preoperative rotatory knee laxity measured using an optical tracking system with manual load application was shown to predict postoperative rotatory knee laxity following ACL reconstruction (ACLR).(3) However, this study was performed with non-standardized external loads leading to potential error. To better inform treatment-decisions, we aimed to determine whether a correlation exists between preoperative QPS and postoperative knee kinematics during running at 6 and 12 months following ACLR with or without lateral extraarticular tenodesis (LET) using a highly precise in vivo analysis system.(4) A positive correlation between preoperative QPS and postoperative anterior-posterior tibial translation and internal-external tibial rotation at 6 and 12 months following ACLR with or without LET was hypothesized.
Methods
Twenty patients with an ACL injury (age 20.8 ± 6.8 years, 12 males) were randomized to undergo anatomic ACLR with or without LET using either bone-patellar tendon-bone or quadriceps tendon autograft as part of a prospective randomized trial (No. NCT0291340). To be included in this study, preoperative examination under anesthesia demonstrating high-grade rotatory instability (=3 mm of lateral compartment translation or a side-to-side difference =50% using PIVOT technology) was required.(2) At 6 and 12 months postoperatively, in vivo kinematic data was collected using dynamic biplanar radiography superimposed with high-resolution computed tomography scans of patients’ knees during downhill running at 2 m/s.(4) Total (maximum subtracted by minimum) anterior-posterior tibial translation and internal-external tibial rotation were calculated from foot-strike to mid-stance of the gait cycle. Spearman’s rho was calculated to evaluate for correlation between preoperative QPS and postoperative kinematics using SPSS statistics (IBM) with p<0.05.
Results
Preoperatively, all patients were confirmed to have high-grade rotatory knee instability with a QPS of 5.0 ± 1.6 mm. No statistically significant correlations were observed between preoperative QPS and total anterior-posterior tibial translation, or between preoperative QPS and total internal-external tibial rotation at 6 and 12 months postoperatively for combined ACLR and ACLR with LET patients as well as ACLR patients or ACLR with LET patients analyzed separately. Discussion: The main finding of this study was that there were no significant correlations between preoperative QPS and postoperative in vivo kinematics at 6 and 12 months following ACLR with or without LET. These findings suggest that preoperative QPS does not correlate with postoperative rotatory knee stability following anatomic ACLR as there are likely other patient, injury, and surgical factors which play a role in determining postoperative knee kinematics. In addition, additional LET does not appear to be necessary in all cases of high-grade rotatory instability as other factors such as graft choice may be more important. In conclusion, additional LET does not appear to be required in all cases of high-grade rotatory instability as preoperative instability does not correlate with postoperative in vivo kinematics following ACLR with or without LET. References: 1)Musahl. AJSM. 2016. 2)Hoshino. KSSTA. 2012. 3)Signorelli. Scand J Med Sci Sports. 2013. 4)Anderst. Med Engl Phys. 2009.
Knee
ACL
Instability
Ligaments
Repair/Reconstruction
Biomechanics

### 20196 Outcomes and complications of open vs. minimally invasive surgical repair of acute achilles tendon rupture. A systematic review and meta-analysis of randomized controlled trials

Ahmed Khalil Attia1
Karim Mahmoud1
Pieter D’Hooghe2
Jason Tyler Bariteau1
Sameh (Sam) A Labib1
Mark Myerson1
1USA
2Qatar
Summary
Open Achilles tendon repair is associated with longer surgical time, higher risk of superficial infection and ankle stiffness, while MIS repair is associated with greater risk of temporary sural nerve palsy. Re-rupture rate and functional outcomes are mostly equivalent.
Data
Background
Acute Achilles tendon rupture is one of the most common sports injuries affecting 18 per 100.000 population, and its operative repair has been gaining ground since the mid-1900s. Traditionally, surgical open repair has provided improved functional outcomes, reduced rerupture rates, and quicker recovery and return to activities at the expense of increased wound complications of infection and skin necrosis in comparison to nonoperative management. Ma and Griffith in 1977 introduced the percutaneous approach, and over the following decades, multiple improved techniques, and modifications thereof, have been described with comparable outcomes to the open repair. AIM: The current study aims to provide updated evidence comparing the open and minimally invasive (MIS) through a comprehensive search of literature published in English, Spanish, Portuguese, and German while avoiding limitations of previous studies such as heterogeneous study designs and a small number of included studies. LEVEL OF EVIDENCE: I, meta-analysis of RCTs.
Methods
Following the PRISMA guidelines, two independent team members searched several databases to identify randomized controlled trials comparing open and MIS Achilles tendon repairs. The primary outcomes were (1) Sural nerve injury, (2) Skin complications, (3) Infection (deep/superficial) whereas the secondary outcomes were (1) AOFAS/ATRS score, (2) surgical time, (3) re-rupture (4) adhesions (5) ankle range of motion.
Results
Ten RCTs qualified for the meta-analysis with a Total of 522 patients. 260 (49.8%) patients had open repair while 262 (50.2%) had MIS repair. The mean surgical time was 51 and 29.7 minute for open and MIS repair, respectively with statistically significant difference (MD= 21.13, 95%CI= 15.50–26.75, p< 0.001; I2= 15%). The pooled mean total complication rate was 15.5% (0–36.4%) in open repair and 10.4% (0–45.5%) in MIS repair, with non-significant difference (RR= 1.50, 95%CI= 0.87–2.57, p= 0.14; I2=40%). The mean re-rupture rate was 2.5% (0–6.8%) in open repair vs. 1.53% (0–4.6%) with MIS repair, with non-significant statistical difference (RR= 1.56, 95%CI= 0.42–5.70, p= 0.50; I2=0%). No cases of sural nerve injury were reported in the open repair group. The mean sural nerve injury was 3.4% (0–7.3%) in the MIS repair group, that was statistically significant (RR= 0.16, 95%CI= 0.03–0.46, p= 0.02; I2=0%). The mean overall deep infection rate reported in the open group was 1.4% (0–5%) while no deep infection was reported in MIS, with no statistically significant difference (RR= 3.24, 95%CI= 0.48 to 20.54, p= 0.23; I2=0%). The mean overall superficial infection rate was 6.04% (0–18.2%) and 0.40% (0–4.5%) for open and MIS repairs, respectively, with statistically significant difference (RR= 5.70, 95%CI= 1.80–18.02, p< 0.001; I2=0%). Average postoperative American Orthopedic Foot and Ankle Society (AOFAS) score was 94.8 and 95.7 for open and MIS repair, respectively with non-significant difference (MD=-0.73, 95%CI=-1.70–0.25, p=0.14; I2= 0%, p< 0.001). There were no significant differences between open and MIS repair groups in skin necrosis and dehiscence rate, adhesions rate, or keloid scar rate.
Conclusion
Open Achilles tendon repair is associated with longer surgical time, higher risk of superficial infection and ankle stiffness, while MIS repair is associated with greater risk of temporary sural nerve palsy. Re-rupture rate and functional outcomes are mostly equivalent. We found MIS to be a safe and reliable technique, however, high quality standardized RCTs are still needed before recommending MIS as the gold standard for the management of Achilles tendon rupture.
Ankle/Foot/Calf
Repair/Reconstruction
Tears
Tendon
Achilles Tendon Injury
Evidence Based Medicine
Outcome Studies
Rupture Tendon
Sutures/Knots/Anchors

### 20183 Outcomes of arthroscopic vs. open broström surgery for chronic lateral ankle instability. A systematic review and meta-analysis of comparative studies

Ahmed Khalil Attia1
Tarek Taha1
Karim Mahmoud2
Kenneth J Hunt1
Sameh (Sam) A Labib1
Pieter D’Hooghe2
1USA
2Qatar
Summary
While technically more demanding, arthroscopic Broström is superior to open Broström-Gould surgery in AOFAS functional scores at six and twelve months, time to return to weight-bearing, and VAS pain scores.
Data
Background
Ankle sprains are the most common ankle injury accounting for up to 85% of all ankle injuries, and nearly 20% of acute ankle sprains progress to chronic lateral ankle instability that requires surgical intervention. In recent years, there has been a growing interest in arthroscopic Broström techniques as an alternative to open surgery. In the past two years alone, four comparative studies have been published. Recent case series and cohort studies showed reliable improvement in clinical and radiographic outcomes with arthroscopic surgery. AIM. The current study aims at providing the foot and ankle surgery community with the most updated evidence comparing outcomes of open to arthroscopic Broström procedure for chronic lateral ankle instability.
Methods
This article was performed following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Relevant comparative studies in English literature were identified between database inceptions to May 2020. The primary outcomes were (1) Functional scores (KAFS, AOFAS) and (2) Pain score on VAS, whereas the secondary outcomes were differences in (1) anterior drawer and talar tilt, (2) surgical time and complications rate, (3) time to return to sports and weight-bearing. Level of Evidence: III
Results
A total of 408 patients in eight studies met the inclusion criteria were subjected to analysis. 193 (47.3%) patients underwent open surgery, while 215 (52.7%) patients underwent arthroscopic surgery. All included studies were retrospective comparative studies except for one randomized controlled trial. The Mean six months-AOFAS was 82.4 vs. 92.25 in open and arthroscopic repair, respectively (MD= 11.36, CI= 0.14–2.56, I2= 90%, p=0.03). The one year-AOFAS was 80.05 vs. 88.6 in open and arthroscopic surgery, respectively (MD= −11.96, CI= −21.26, −2.76, I2= 82%, p= 0.01). The mean six month-VAS was 1.7 and 1.4 in open and arthroscopic repair, respectively (MD= −0.38, CI= −0.54, −0.21, I2=78%, p<0.001).The mean one year VAS was 2.05 and 1.45 in open and arthroscopic repair, respectively (MD= 0.31, CI= 0.09 to 0.54, I2=0%, p<0.001). The mean postoperative KAFS was 82.7 and 87.5 in open and arthroscopic repair, respectively, with insignificant differences (p= 0.63). The mean time to weight-bearing was 14.25 weeks and 9.0 weeks in open and arthroscopic repair, respectively (MD=1.89, CI= 1.24 to 2.54, I2=99%, p<0.001). There were no statistically significant differences in the time to RTP, postoperative anterior drawer, postoperative talar tilt, and operative time. The total complications rate in open and arthroscopic repair was 21.3% vs. 10%, with statistical insignificance (OR= 0.73, 95%CI= 0.39 to 1.38, I2=0%, p= 0.34).
Conclusion
While technically more demanding, arthroscopic Broström is superior to open Broström-Gould surgery in AOFAS functional scores at six and twelve months, time to return to weight-bearing, and VAS pain scores. Operative time, complications rate, talar tilt, and anterior drawer tests are excellent and statistically comparable. Long-term clinical trials are required before recommending arthroscopic Broström as the new gold standard.
Ankle/Foot/Calf
Instability
Ligaments
Repair/Reconstruction
Anterior Talofibrilar Ligament
Arthroscopy
Calcaneo Fibular Ligament
Evidence Based Medicine
Outcome Studies

### 20186 Return to play and fracture union after surgical management of jones fracture in athletes. A systematic review and meta-analysis

Ahmed Khalil Attia1
Tarek Taha1
Geraldine Kong2
AbdulJabbar Alhammoud2
Karim Mahmoud1
Mark Myerson1
1USA
2Qatar
Summary
Intramedullary screw fixation is superior to conservative management as it leads to a higher rate of return to play, shorter time to return, higher rate of union, shorter time to union, and improved functional outcomes.
Data
Background
Proximal fifth metatarsal fractures are among the most common forefoot injuries in athletes. Management of this injury can be challenging due to delayed union and refracture. Intramedullary screw fixation rather than conservative management has been recommended in the athletic population. AIM: This meta-analysis aims to provide an updated summary of return to play (RTP) rate and time with regard to the management, whether operative or non-operative, after Jones fractures in athletes only. We also explore the characteristic of the union such as time and rate, and complications such as refracture.
Methods
Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, two independent team members searched several databases including PubMed, MEDLINE, EMBASE, Web of Science, Cochrane Library, and ClinicalTrials.gov throughout November 2019 to identify studies reporting on Jones fractures of the 5th metatarsal, exclusively in athletes. The primary outcomes were return to play rate and time to return to play, whereas the secondary outcomes were union rate, time to union, and refracture.
Results
Out of 168 studies identified, 22 studies where eligible for meta-analysis with a total of 646 Jones fractures. The overall RTP rate was 98.4% (97.3%–99.4%) in 626 out of 646. The RTP rate in IM screw only was 98.8% (97.8%–99.7%), in other surgical fixations methods (plate, mini fix) was 98.4% (95.8%–100%) whereas in conservative management was 71.6% (45.6%–97.6%). There were three studies directly comparing the RTP in surgical versus conservative management, which showed significant superiority in favor of the surgical group OR: 0.033 CI:(0.005–0.215) P-value <0.001. The RTP according to type of sport was 99% (97.5%–100%) in American football, 91.1% (82.2%–99.4%)in basketball and 96.6%% (92.6%–100%) in Soccer. The overall time to RTP was 9.6 (8.5–10.7) weeks. The time to RTP in the surgical group (IM screw) was 9.6 (8.3–10.9) weeks, significantly less than conservative groups, which was 13.05 (8.15–17.95) weeks. The pooled union rate in operative group (excluding refracture) was 97.3% (95.1%–99.4%), whereas the pooled union rate in the conservative group was 71.4% (49.1%–93.7%). The overall time to union was 9.1(7.7–10.4) weeks. Time to union in IM screw group 8.2 (7.5–9) weeks was shorter than conservative group 13.7 (12.7–14.6). The rate of delayed union was 2.5% (1.2%–3.7%), and the overall refracture rate was 10.2% (5.9%–14.5%).
Conclusion
Return to play following surgical management of Jones fractures in athletes is excellent regardless of the implant used and sport. Intramedullary screw fixation is superior to conservative management as it leads to a higher rate of return to play, shorter time to return, higher rate of union, shorter time to union, and improved functional outcomes. The authors recommend surgical fixation for all Jones fractures in athletes.
Ankle/Foot/Calf
Bones
Implant
Trauma
Evidence Based Medicine
Metatarsal Fracture
Outcome Studies
Professional Athletes/Olympians

### 20240 Comparison of outcomes of high tibial osteotomy using two principles of pre-operative planning

Nisarg Shah
Rafael Sales Fernández
Kevin Syam
Benjamin Coupe
Sijith Sasi
UK
Summary
Comparison of radiological and functional outcomes of high tibial osteotomy between two principles of pre-operative planning
Data
Objective
High tibial osteotomy (HTO) is a useful alternative to knee replacement in the relatively young and active patient with medial compartment osteoarthritis. Careful pre-operative planning is required to attain the desired correction of mechanical axis. It is also important to prevent excessive proximal tibial valgus in order to avoid adverse outcomes. The objective of this study was to compare the radiological and functional outcomes of HTO by two different principles of pre-operative planning.
Methods
A total of 100 patients (109 knees), 67 (71 knees) under surgeon 1 and 33 (38 knees) under surgeon 2 were retrospectively studied. Surgeon 1 used ‘Miniaci’ method for planning with focus on achieving Mikulicz point at 62.5% (principle 1). Surgeon 2 employed planning software (TraumaCad) and tried to keep the mechanical medial proximal tibial angle (mMPTA) < 930 (principle 2). Mikulicz point and mMPTA were compared on long leg radiographs, taken before and 3 months post surgery. Under correction was defined as Mikulicz point < 50% and over correction as > 70%. Functional outcomes were determined using Oxford Knee Score (OKS), Knee Injury and Osteoarthritis Outcome Score (KOOS) and EQ5D5L pre-operatively, at 1 and 2 year follow up.
Results
Pre-operative Mikulicz point, mMTPA and functional scores were comparable between the groups. Mean post-operative mMPTA was significantly higher in group 1 (93.95 (SD 2.76)) compared to group 2 (92.13 (SD 2.37)) (p=0.01). In Group 1, 81.7% patients had post-operative correction between 50–70% compared to 65.8% in group 2. But this was not statistically significant (p=0.06). However, there were significant number of under corrections in group 2 (32.4%) in comparison to group 1 (9.8%) (p=0.003). Mean OKS and KOOS improved significantly in both the groups after surgery, while EQ5D improved only in group 1.
Conclusion
The conservative approach (principle 2) of planning for an HTO appears to be effective in preventing excessive valgus at the proximal tibia, but with a higher possibility of under correction. Though not statistically significant, there appears to be a trend towards the principle 1 being more consistent in achieving the desired correction. The functional outcomes showed more positive trend with principle 1. A longer follow up is needed to study the long-term implications of these principles.
Orthopaedic Sports Medicine
Osteoarthritis
Osteotomy
Bones
Cartilage
Knee
X-ray

### 20227 Return to sports following medial patellofemoral ligament reconstruction for recurrent patellar dislocation

Pierre Meynard1
Matthieu Malatray1
Elliot Sappey-Marinier1
Robert A Magnussen2
Sebastien Lustig1
Elvire Servien1
1France
2USA
Summary
Isolated MPFL reconstruction allowed return to pre-injury sports in 91% of patients, with 67% of patients returning to the same or higher level than pre-injury.
Data
Background
Recurrent patellar dislocation (RPD) is a common knee disorders in young, active patients. Medial patellofemoral ligament reconstruction (MPFLR) can restore knee stability and function, but the rate of return to sports is less clear.
Purpose to evaluate rate of return to sport following treatment of RPD with isolated MPFLR.
Methods
Between January 2011 and May 2018, 113 patients with RPD were treated with isolated MPFLR at an academic center. Pre-injury sports participation and Tegner score, pre-operative subjective IKDC score, time to return to sports, and post-operative Tegner and subjective IKDC scores were collected, with a minimum of follow-up of 2 years.
Results
One hundred and three patients (91%) were evaluated at a mean of 4.5 ± 2.5 years post-operative. Ninety-two patients (89%) participated in sports prior to onset of patellar instability. At final follow-up, 84 of these 92 patients (91%) were able to return to sports. The mean time from surgery to return to sports was 10.4 ± 8.6 months (range: 2 to 48 months). Sixty-two patients (74%) returned to the same (50 patients) or higher (12 patients) level. Twenty-two patients (26%) returned at a lower level. Nineteen of these patients attributed this decreased participation to ongoing knee problems. The mean Tegner score was noted to decrease from 5.2 ± 1.6 pre-injury to 4.7 ± 1.4 post-operatively (p=0.02).
Conclusion
Isolated MPFL reconstruction allowed return to pre-injury sports in 91% of patients, with 67% of patients returning to the same or higher level than pre-injury. Mean time to return to sports was 10 months and post-operative Tegner score was noted to be modestly decreased from pre-injury level.
Knee
Capsuloligamentous Complex
Dislocation
Repair/Reconstruction
Sport Specific Injuries
Sport Specific Population
X-ray

### 20225 Restoring knee phenotype and joint line obliquity reduces postoperative pain after primary TKA

Elliot Sappey-Marinier
Cécile Batailler
John Swan
Elvire Servien
Sebastien Lustig
France
Summary
Restoring constitutional apex distal joint line obliquity resulted in improved outcomes with less postoperative pain.
Data
Aim
In Total Knee Arthroplasty (TKA), knee phenotype including joint line obliquity are of interest regarding surgical realignment strategies. This study aims to assess the effect of restoring knee phenotype on clinical outcomes.
Methods
A retrospective analysis was performed on prospective data, including 1078 primary osteoarthritic knees in 936 patients. International Knee Society Scores and standardized long-leg radiographs were collected preoperatively and two years postoperatively. Patients were categorized using the Coronal Plane Alignment of the Knee (CPAK) classification including the Lateral-Distal-Femoral-Angle (LDFA) and Medial-Proximal-Tibial-Angle (MPTA), allowing knee phenotypes to be categorized considering the arithmetic Hip-Knee-Ankle (aHKA) angle (MPTA-LDFA) as measure of constitutional alignment, and Joint Line Obliquity (JLO) (MPTA+LDFA). Patients with surgically restored preoperative constitutional knee phenotype were compared with patients without restored constitutional knee phenotypes. Results 33.4% of patients had constitutional knee varus with apex distal JLO. 63.5% of patients had preoperative apex distal JLO. Postoperatively, 57.8% of patients had a neutral HKA (-2° to 2°) and a neutral JLO (-3° and 3°), with only 18% of patients with restored constitutional knee phenotype. Of these patients, less postoperative pain was observed in patients where apex distal JLO was restored compared to non-restored apex distal JLO (pain score 46.7 vs. 44.6; p=0.02). Other categories of restored JLO or HKA angle were not associated with improved outcomes.
Conclusion
Restoring constitutional apex distal joint line obliquity resulted in improved outcomes with less postoperative pain. This emphasizes the need for a personalized TKA surgical realignment strategy that considers joint line obliquity and not only the HKA angle.
Knee
Arthroplasty
Bones
Osteoarthritis
Elderly
X-ray

### 19926 Increased glenohumeral joint loads due to a supraspinatus tear can be reversed with rotator cuff repair: a biomechanical investigation of joint preservation

Lukas Nawid Muench1
Knut Beitzel1
Daniel P Berthold1
Alexander Otto1
Felix Dyrna1
Ryan M Bell2
Elifho Obopilwe2
Mark P Cote2
Andreas B Imhoff1
Augustus D Mazzocca2
1Germany
2USA
Summary
In a dynamic biomechanical cadaveric model, increased glenohumeral joint loads due to a full-thickness supraspinatus tear can be reversed with rotator cuff repair, while preventing superior humeral head migration and decreasing compensatory deltoid forces.
Data
Background
Rotator cuff tears (RCT) have been shown to result in altered shoulder kinematics with disruption of the biomechanical synergy of the rotator cuff and deltoid muscles, which may be responsible for the correlation between RTCs and degenerative changes of the glenohumeral joint. The purpose was to evaluate the effect of an isolated full-thickness supraspinatus (SSP) tear on glenohumeral kinematics, contact mechanics, and quantify improvement following rotator cuff repair (RCR). The authors hypothesized that RCR would reverse the increased glenohumeral joint loads caused by a full-thickness SSP tear.
Methods
Ten fresh-frozen cadaveric shoulders (mean age: 63.1 ± 4.6 years) were tested using a dynamic shoulder simulator. A pressure mapping sensor was placed between the humeral head and glenoid. Each specimen underwent the following three conditions: (1) native, (2) isolated full-thickness SSP tear, (3) RCR. Maximum abduction angle (MAA) and superior humeral head migration (SHM) were measured using 3D motion tracking software. Cumulative deltoid force (CDF) and glenohumeral contact mechanics, including contact area (GCA) and contact pressure (GCP), were assessed at the resting position as well as at 15°, 30°, 45°, and 60° of glenohumeral abduction. An a priori power analysis was performed to determine detectable differences in contact pressure given estimated standard deviations. Assuming a common standard deviation of 15kPa, a sample size of 6 specimens would provide 80% power to detect a 25kPa difference in pressure at an a level of .05. Repeated measures analysis of variance was performed to examine differences in MAA, SHM, glenohumeral contact mechanics, and CDF among the various testing conditions. When significant, post-hoc paired t tests with a Bonferroni corrected alpha were performed to determine which pairwise comparisons were statistically significant. The alpha level for all analyses was set at .05.
Results
Compared to native, the SSP tear resulted in a significant decrease in MAA (Delta: −8.3°; P <.001) along with a SHM of 6.4 ± 3.8 mm, while significantly increasing CDF (Delta: 20.5N; P = .008), GCP (Delta: 63.1kPa; P < .001), and peak GCP (Delta: 278.6kPa; P < .001) as well as decreasing GCA (Delta: −45.8 mm2; P < .001) at each degree of glenohumeral abduction. RCR reduced SHM to 1.2 ± 2.5 mm, while restoring native MAA, CDF (Delta: 1.8N), GCA (Delta: 4.5 mm2), GCP (Delta: −4.5kPa) and peak GCP (Delta: 19.9kPa) at each degree of abduction (P > .999, respectively).
Conclusion
In a dynamic biomechanical cadaveric model, increased glenohumeral joint loads due to a full-thickness SSP tear can be reversed with RCR. More specifically, RCR restored native glenohumeral contact area and contact pressure, while preventing superior humeral head migration and decreasing compensatory deltoid forces. These time-zero observations indicate that isolated full-thickness SSP tears should undergo repair, in order to reverse altered loading conditions and improve overall shoulder function. More importantly, this potentially prevents progressive cartilage degeneration, while preserving the native glenohumeral joint.
Shoulder
Arthroscopy
Glenohumeral
Repair/Reconstruction
Tears
Biomechanics
Cartilage
Cartilage Injuries
Supraespinoatus Tendon Injury
Sutures/Knots/Anchors
Tendon

### 19928 Comparison of lower trapezius and latissimus dorsi transfer for irreparable posterosuperior rotator cuff tears: a dynamic biomechanical investigation

Lukas Nawid Muench1
Augustus D Mazzocca2
Daniel P Berthold1
Cameron Kia2
Elifho Obopilwe2
Mark P Cote2
Andreas B Imhoff1
Bastian Scheiderer1
Bassem T Elhassan2
Knut Beitzel1
1Germany
2USA
Summary
In the setting of irreparable posterosuperior rotator cuff tears, transfer of the lower trapezius may restore native glenohumeral kinematics more sufficiently when compared to latissimus dorsi transfer, while preventing loss of abduction motion and superior humeral head migration.
Data
Background
Anatomically, lower trapezius transfer (LTT) may be better positioned for restoring the muscular force couple in the setting of irreparable posterosuperior rotator cuff tears (PSRCT) when compared to latissimus dorsi transfer (LDT). The purpose was to evaluate the effect of LTT and LDT on maximum abduction angle (MAA), superior humeral head migration (SHM), and cumulative deltoid forces (CDF) using a dynamic shoulder model. It was hypothesized that the LTT would better restore native glenohumeral kinematics when compared to the LDT.
Methods
Ten fresh-frozen cadaveric shoulders (mean age: 56.5±17.2 years) were tested using a dynamic shoulder simulator. MAA, SHM, and CDF were compared across four conditions: (1) native; (2) irreparable PSRCT; (3) LTT using an Achilles tendon allograft (mean graft thickness: 5.3 ± 0.5 mm), as previously described by Elhassan et al.; and (4) LDT. MAA and SHM were measured using 3-dimensional motion tracking. CDF was recorded in real time throughout dynamic abduction motion by load cells connected to actuators and was calculated as the summation of anterior, middle, and posterior deltoid forces. A sample size of 6 specimens will provide 80% power to detect a 1° difference in shoulder angle at an a level of 0.05. Repeated measures analysis of variance was performed to examine differences in MAA, SHM, and CDF among the various testing conditions. When significant, post-hoc paired t tests with a corrected alpha using the Holm Bonferroni sequential correction method were performed to determine which pairwise comparisons were statistically significant. The alpha level for all analyses was set at 0.05.
Results
Compared to the native state, the PSRCT resulted in a significant decrease (Delta: −24.1°; P < 0.001) in MAA, with a subsequent significant increase after LTT (Delta: 13.1°; P < 0.001) and LDT (Delta: 8.9°; P < 0.001). LTT achieved a significantly greater MAA than LDT (Delta: 4.2°; P = 0.004). Regarding SHM, both LTT (Delta: −9.4 mm; P < 0.001) and LDT (Delta: −5.0 mm; P = 0.008) demonstrated a significant decrease when compared to the PSRCT state. LTT also achieved significantly less SHM compared to the LDT (Delta: −4.4 mm; P = 0.011). Further, only the LTT resulted in a significant decrease in CDF when compared to the PSRCT state (Delta: −21.3N; P = 0.048), while LTT and LDT showed similar CDF (Delta: -11.3N; P = 0.346). However, none of the techniques was able to restore MAA, SHM, and CDF of the native shoulder (P < 0.001, respectively).
Conclusion
LTT and LDT achieved a significant increase in maximum abduction angle along with significantly less superior humeral head migration compared to the PSRCT state. While LTT required significantly less cumulative deltoid forces compared to the PSRCT state, this was not observed for LDT. Further, LTT prevented loss of abduction motion and superior head migration more sufficiently when compared to LDT. In the challenging treatment of irreparable PSRCTs, transfer of the lower trapezius may restore native glenohumeral kinematics more sufficiently, potentially leading to improved postoperative functional outcomes.
Shoulder
Allograft
Glenohumeral
Tears
Biomechanics
Infraespinatus Tendon Injury
Repair/Reconstruction
Supraespinoatus Tendon Injury
Tendon

### 19922 Reverse shoulder arthroplasty humeral and glenoid variations influence on range of motion: a standardized computer model study

Antonio Arenas-Miquelez1
Richard James Murphy2
Andrea Rosa3
Davide Caironi4
Matthias A Zumstein3
1Australia
2UK
3Switzerland
4Italy
Summary
The semi-inlay 145° stem combined with 4 mm lateralization and 2 mm inferior eccentricity glenosphere is the middle ground for the most all-purpose approach in RTSA.
Data
Background
There have been multiple modifications to the initial reverse total shoulder arthroplasty (RTSA) designed by Grammont to improve range of motion (ROM) and avoid notching. The effect of these changes in shoulder kinematics and the best compromise for ROM is still under debate.
Purpose
To evaluate on a computer model scenario the influence of humeral design, humeral neck-shaft angle (NSA), glenoid lateralization, and glenoid eccentricity on ROM of RTSA. Methods We created a 3-dimensional computer model from computed tomography scans of 13 patients with primary osteoarthritis simulating implantation of a standardized reverse shoulder arthroplasty. We created 7 different stem and 7 different glenoshere configurations to analyze the effect of 4 different variables on impingement-free ROM: humeral design (inlay vs. semi-inlay vs. onlay), humeral NSA (135° vs. 145° vs. 155°), glenoid lateralization, and glenoid eccentricity on ROM. Statistical analysis was performed using Kruskal-Wallis analysis to compare ROMs and applied a Dunn correction for multiple inter-group comparisons. Results The use of different humeral stem designs did not have a significant effect on total global ROM. Reducing NSA demonstrated a significant increase in adduction, and external and internal rotation in adduction, whereas a decrease in abduction and external rotation in abduction. Glenosphere lateralization was the most effective method for increasing total global ROM (P < .0001); however, extreme lateralization (+12 mm) did not show significant benefit compared with moderate lateralization (+4 mm). Glenosphere eccentricity increased only adduction and internal rotation in adduction.
Conclusion
Only glenoid lateralization has a significant effect on increasing total global ROM in RTSA. The use of the semi-inlay 145° model combined with 4 mm lateralization and 2 mm inferior eccentricity represents the middle ground and the most universal approach in RTSA.
Shoulder
Glenohumeral
Osteoarthritis
Total Joint Replacement
Arthroplasty
Basic Science
Bones
CT-Scan

### 19805 What is the most reliable method of measuring glenoid bone loss in anterior glenohumeral instability? A cadaveric study comparing different measurement techniques for glenoid bone loss

Antonio Arenas-Miquelez1
Danè Dabirrahmani1
Gaurav Mahesh Sharma2
Petra Graham1
Richard Appleyard1
Desmond John Bokor1
Kalman John Piper1
Sumit Raniga1
1Australia
2India
Summary
Glenoid bone loss calculation presents variability depending on the measurement technique, with different consistencies and accuracies. The Barchilon method, based on area measurement, should be used in the surgical decision making process as it presented the best combined consistency and accuracy.
Data
Background
Preoperative quantification of bone loss has a significant impact on surgical decision making and patient outcomes. Various measurement techniques for calculating glenoid bone loss have been proposed in the literature. To date, no studies have directly compared measurement techniques in order to determine which techniques, if any, is the most reliable. The aim of this investigation was to identify the most consistent and accurate measurement technique(s) for measuring glenoid bone loss in anterior glenohumeral instability.
Methods
Six fresh-frozen human shoulders with 3 incremental bone defects were sequentially created resulting in a total of 18 glenoid bone defect samples. Two- and three-dimensional representative CT scan en face images were used for analysis. Six observers (three experienced and three with less experience) measured the bone defect of all the samples with HOROS imaging software using 5 commonly employed methods. The methods included 2 linear techniques (Shaha, Griffith), 2 surface techniques (Barchilon, PICO) and one statistical shape model formula (Giles). Intraclass correlation (ICC) using a consistency model was used to determine consistency between surgeons for each of the measurement methods. Paired t-tests were used to calculate the accuracy of each measurement technique relative to physical measurement.
Results
For more experienced observers, all methods indicated good consistency (ICC>0.75), except the Shaha method which indicated moderate consistency (0.65<ICC<0.75). Estimated consistency among the experienced observers was better for 2D than 3D images though the differences were not significant (intervals contained 0). For less experienced observers the Giles method in 2D had the highest estimated consistency (ICC: 0.88, 95%CI: 0.76, 0.95), though Giles, Barchilon, Griffith and PICO were not significantly different. Among less experienced observers the 2D images using Barchilon and Giles methods had significantly higher consistency than the 3D images. Regarding accuracy, most of the methods significantly overestimated the actual physical measurements by a small (mean within 5%) amount. The smallest bias was observed for the 2D Barchilon measurements and the largest differences were observed for Giles and Griffith methods for both observer types.
Conclusion
Glenoid bone loss calculation presents variability depending on the measurement technique, with different consistencies and accuracies. We recommend the use of the Barchilon method by surgeons who frequently measure glenoid bone loss because it presents the best combined consistency and accuracy. However, if glenoid bone loss is measured occasionally, the most consistent method is Giles method, although an adjustment for the overestimation bias may be required.
Shoulder
Glenohumeral
Instability
Basic Science
Bones
CT-Scan
Dislocation
Glenoid Fracture

### 19886 Same knee, different goals: patients and surgeons have different priorities related to ACL reconstructions and surgeons are resistant to changing clinical practice

Hana Marmura1
Dianne M Bryant1
Trevor B Birmingham1
Kurt P Spindler2
Christopher C Kaeding2
Tim Spalding3
Alan Getgood1
2USA
3UK
Summary
An exploration of patients’ and surgeons’ priorities related to anterior cruciate ligament reconstructions, and the magnitude of treatment effects in evidence that may influence surgical practice change.
Data
Background
The priorities of patients should be shared by those treating them. Patients and surgeons are likely to have different priorities surrounding anterior cruciate ligament reconstruction (ACLR), with implications for shared decision-making and patient education. The optimal surgical approach for ACLR is constantly evolving, and the magnitude of treatment effect necessary for evidence to change surgical practice is unknown.
Purpose
The aim of this study was to determine (1) the priorities of surgeons and patients when making decisions regarding ACLR and (2) the magnitude of reduction in ACLR graft failure risk that orthopaedic surgeons require before changing practice.
Methods
This study followed a cross-sectional survey design. Three distinct electronic surveys were administered to pre-operative ACLR patients, post-operative ACLR patients, and orthopaedic surgeons in the ACL Study Group. Patients and surgeons were asked about the importance of various outcomes and considerations pertaining to ACLR. Surgeons were asked scenario-based questions regarding changing practice for ACLR based on new research.
Results
Surgeons were more likely to prioritize outcomes related to the surgical knee itself, whereas patients were more likely to prioritize outcomes related to their daily lifestyle and activities. Knee instability and risk of re-injury were unanimous top priorities among all three groups. A mean relative risk reduction in ACLR graft failure of about 50% was required by orthopaedic surgeons to change practice regardless of the type of change, or patient risk profile.
Conclusion
There are discrepancies between the priorities of surgeons and patients, and orthopaedic surgeons appear resistant to changing practice for ACLR.
Knee
ACL
Ligaments
Repair/Reconstruction
Tears
Allograft
Anterolateral Ligament
Autograft
Double Bundle
Evidence Based Medicine
Instability
Osteoarthritis
Practice Management
Single Bundle

### 19888 Validation of a risk calculator to personalize graft choice and reduce rupture rates for anterior cruciate ligament reconstruction

Hana Marmura1
Alan Getgood1
Kurt P Spindler1
Michael W Kattan1
Isaac Briskin2
Dianne M Bryant1
2USA
Summary
Validation of an ACL autograft risk calculator appropriate for shared decision making and clinical practice.
Data
Background
Anterior cruciate ligament reconstructions (ACLR) fail at an alarmingly high rate in young active individuals. The Multicenter Orthopaedic Outcomes Network (MOON) knee group has developed an autograft risk calculator that uses characteristics of the patient and their lifestyle to predict the probability of graft rupture if the surgeon uses a hamstring tendon (HT) or a bone patellar tendon bone (BPTB) graft to reconstruct the ligament. If validated, this risk calculator can be used during the shared decision-making process to make optimal ACLR autograft choices and reduce rupture rates. The STABILITY 1 randomized clinical trial offers a large, rigorously collected dataset of similar young active patients, who received HT autograft with or without lateral extra-articular tenodesis (LET) for ACLR for validation.
Purpose
To validate the ACLR graft rupture risk calculator in a large external dataset, and to investigate the utility of both BPTB and LET for ACLR.
Methods
The model predictors for the risk calculator include age, sex, body mass index, sport played at the time of injury, Marx activity score, pre-operative knee laxity, and graft type. The STABILITY 1 trial dataset was used for external validation. Discriminative ability, calibration, and diagnostic test validity of the model were assessed. Finally, predictor strength in the initial and validation samples were compared.
Results
The model showed acceptable discriminative ability (AUC = 0.73), calibration (Brier score = 0.07), and specificity (85.3%) to detect patients who will suffer a graft rupture. Age, high-grade pre-operative knee laxity and graft type are significant predictors of graft rupture in young active patients. Both BPTB and the addition of LET to HT are protective against graft rupture versus HT autograft alone.
Conclusion
The MOON risk calculator is a valid predictor of ACLR graft rupture appropriate for clinical practice. This study provides further evidence supporting the idea that isolated HT autografts should be avoided for young active patients undergoing ACLR.
Knee
ACL
Autograft
Ligaments
Tears
Failed
Female Athletes
Instability
Outcome Studies
Preventative Sports Medicine
Repair/Reconstruction
Sport Specific Population

### 19889 Meniscal repair at the time of primary ACLR does not negatively influence short term knee stability, graft rupture rates, or patient reported outcome measures: the stability experience

Andrew Firth1
Hana Marmura1
Lachlan Batty2
Dianne M Bryant1
Alan Getgood1
Stability Study Group1
2Australia
Summary
The reduction in patient reported outcome scores associated with medial meniscal repair at the time of primary ACL reconstruction are not clinically significant.
Data
Background
Concomitant meniscal injury is frequently seen in the anterior cruciate ligament (ACL) deficient or injured knee. Higher rates of osteoarthritis have been demonstrated in ACL injured knees when concomitant meniscal injury is present and higher rates of ACL graft failure have been seen in meniscal deficient knees. In this context, there has been significant interest in meniscal repair at the time of ACL reconstruction.
Purpose
To assess how meniscal repair and excision impact patient reported outcome measures (PROMs), knee stability, and early graft rupture rates following primary hamstring anterior cruciate ligament reconstruction (ACLR) in a group of young active patients where meniscal repair is commonly advocated.
Methods
Six hundred and eighteen patients under 25 years of age at high-risk of graft failure following ACLR were recruited to the Stability 1 study. Multivariable regression models were developed to identify surgical and demographic predictors of Knee Osteoarthritis Outcomes Survey (KOOS), International Knee Documentation Committee Subjective Knee Form (IKDC), ACL Quality of Life Questionnaire (ACL-QOL) and Marx Activity Rating Scale (MARS) scores. Chi Square tests of independence were used to explore the association between meniscal treatment, graft rupture, and rotatory knee laxity.
Results
Medial meniscus repair was associated with worse outcomes on the KOOS (B = −1.32, 95% CI: −1.57 to −1.10, p = 0.003), IKDC (B = −1.66, 95% CI: −1.53 to −1.02, p = 0.031) and ACL-QOL (B = −1.25, 95% CI: −1.61 to 1.02, p = 0.087). Other important predictors of post-operative PROMs include age, sex, and baseline scores. The associations between medial meniscal treatment and outcome scores indicated small, clinically insignificant changes based on reported minimal important differences. There was no significant association between meniscal treatment and graft rupture or rotatory knee laxity.
Conclusion
While repairing the medial meniscus may result in a small reduction in PROM scores at two-year follow up, these differences are not likely to be important to patients or clinicians. Any surgical morbidity associated with meniscal repair appears negligible in terms of PROMs. Meniscal repair does not affect rotatory laxity or graft failure rates in the short term.
Knee
Meniscus
Repair/Reconstruction
Tears
ACL
Arthroscopy
Autograft
Cartilage
Instability
Lateral
Ligaments
Medial

### 19802 The “Bankart knee”: Biomechanical consequences of a posterolateral tibia plateau impression fracture as concomitant injury of ACL rupture

Christoph Kittl1
Elmar Herbst1
Christian Fink2
Robert Smigielski3
Friedrich Greis1
Michael J Raschke1
Mirco Herbort1
1Germany
2Austria
3Poland
Summary
The results of this biomechanical study show that the high-grade impression fractures of the posterolater aspect of the tibial plateau increase the anterolateral instability in ACL-deficient knees.
Data
Introduction
Posterolateral impression fractures of the tibial plateau seen as depression of the articular surface with breach of the cortical bone are common concomitant injuries of an ACL rupture. They are caused by the mechanism of high-energy pivot-shift trauma, in which the lateral tibial plateau subluxate anteriorly, resulting in a violent collision of the anterolateral aspect of the lateral femoral condyle and posterolateral area of the tibial plateau. Aim: The aim of this biomechanical cadaver study was to evaluate the destabilizing effect of high-grade posterolateral tibia plateau fractures on kinematics of the ACL-deficient joint.
Material and Methods
8 human fresh-frozen cadaveric knees were tested using a six-degree of freedom robotic setup (KR 125, KUKA Robotics, Augsburg, Germany) with an attached optical tracking system (Optotrack Certus Motion Capture, Northern Digital, Ontario, Canada). After the passive path from 0–90° was established, simulated Lachman test and pivot-shift test as well external rotation (ER, 4Nm) and internal rotation (IR, 4Nm) were applied at 0°, 30°, 60°, and 90° of joint flexion under constant 200 N axial loading. All the parameters were initially tested in the intact and the ACL-deficient state, followed by 2 different types of posterolateral impression fractures in the ACL-deficient knees. The dislocation height was 10 mm and the width 15 mm constantly in both groups. The intraarticular depth of the fracture corresponded to the half of the width of the posterior horn of the lateral meniscus in the first group (Bankart 1), and 100% of the meniscus width in the second group, marked Bankart 2. A two-way repeated measures ANOVA with post-hoc Bonferroni corrections for multiple comparisons was performed to evaluate the effect of different states over different angles on tibial translation. The significance level was set to 0.05.
Results
There was a significant decrease in knee stability after both types of additional posterolateral tibial plateau fractures in the ACL-deficient specimens with increased anterior translation following the simulated Lachman test in up to 30° of knee flexion (p < 0.05). The same effect was recorded in regards to the anterolateral rotational (ALR) instability. Simulated Pivot shift test in near extension position (0° and 30°), as well as IR test (0° to 30°), showed significantly increased instability in both types of additional fractures in ACL-deprived state (p < 0.05). Following ER and posterior drawer test, ACL deficiency and concomitant fractures did not influence knee kinematics.
Conclusion
The results of this study demonstrate that high-grade impression fractures of the posterolateral aspect of the tibial plateau increase the instability of the ACL-deficient knees and result in a considerable increase in translational and ALR instability. Comparably to the shoulder with its integrity of the labrum and the glenoid as his bony ground, the posterolateral tibia plateau impression fracture seems to work like a bony Bankart lesion which results in instability of the joint by destabilizing the posterior horn of the lateral meniscus. Considering their potential effects on the kinematics of the ACL-deprived knees, these fractures should be taken into consideration in the overall treatment decision-making process.
Knee
Bones
Instability
Meniscus
ACL
Biomechanics
Capsuloligamentous Complex
Lateral
Ligaments
Tibial Plateau Fracture

### 19900 The body mass index and the J-sign determine the quality of life in patients with lateral patellar instability

Isidora Jovandic
Felix Zimmermann
Peter Balcarek
Germany
Summary
The results of this cross-sectional study show that among various demographic, clinical, and pathoanatomic factors, increased BMI and presence of high-grade J-sign have a significant impact on subjective disease-specific QOL in patients with LPD.
Data
Background
Although the prevalence and combined prevalence of pathoanatomic risk factors for lateral patellar dislocation (LPD) and their impact on postoperative outcome scores have been described, there is still limited evidence regarding their influence on patients’ disease-specific quality of life (QOL).
Purpose
The goal of this study was to determine whether and to what degree certain demographic, clinical, and pathoanatomic factors impact subjective disease-specific QOL in patients with LPD.
Methods
A total of 182 consecutive patients (male/female 70/112; mean age 23.6 ± 7.3 years) with a history of LPD were prospectively enrolled in this study. Patient age, body mass index (BMI), number of dislocations, reversed-dynamic patellar apprehension test (ReDPAT), and J-sign severity were assessed. In addition, evaluation of pathoanatomic risk factors included assessment of trochlear dysplasia, tibial tubercle-trochlear groove (TT-TG) distance, tibial tubercle-posterior cruciate ligament (TT-PCL) distance, Caton-Deschamps (CD) index, and valgus/valgus malalignment. The statistical analysis evaluated the relationships among those variables and determined their ability to predict the Banff Patellofemoral Instability Instrument 2.0 (BPII 2.0) as a disease-specific QOL measure. Using Spearman correlation, ANOVA and Fisher’s exact test, all variables with ANOVA p = 0.1 or Spearman’s abs (rho) > 0.1 were entered into a multivariate linear model using backwards stepwise selection.
Results
Analysis of the individual variables’ ability to predict BPII 2.0 score values revealed ‘age’, ‘BMI’, ‘ReDPAT’, ‘high grade of trochlear dysplasia’ (Dejour B-D), and ‘high-grade J-Sign’ (Grade II and III) as possible relevant variables (one-way ANOVA (p = 0.1); Spearman’s correlation (abs(rho) > 0.1)). Backward-stepwise multivariate regression analysis yielded a final parsimonious model that included the factors ‘BMI’ and ‘J-Sign (Grade II and III)’ as the most relevant parameters influencing BPII 2.0 score values (adjusted R2 = 0.418; p < 0.001)), with a cutoff value for BMI found at 28 kg/m2 (Tukey test; p=0.01).
Conclusion
The main results of this study indicate that the presence of a high-grade J-sign and an increased BMI contribute significantly to inferior QOL score values in patients with recurrent LPD when evaluated with the BPII 2.0. Because BMI is a modifiable factor, this information might be helpful for the clinical decision-making process.
Knee
Instability
Patellofemoral
Outcome Studies
Recurrent Subluxation and Dislocation

### 19828 Increased retear risk after arthroscopic supraspinatus tendon repair in patients with a higher csa and ai: long-term follow up

Gert-Jan Opsomer
Lotte Verstuyft
Stijn Muermans
Belgium
Summary
Also at long-term follow-up, a higher Critical Shoulder Angle and Acromion Index significantly increased the retear risk after arthroscopic supraspinatus tendon repair.
Data
Aim
To evaluate the long-term effect of the critical shoulder angle (CSA) and acromion index (AI) on the postoperative healing rate after arthroscopic supraspinatus tendon repair.
Background
The negative effect of a high CSA and AI on the short-term healing rate after arthroscopic repair of the supraspinatus tendons is already known. No studies with a long-term follow-up are yet published.
Methods
Patients with a symptomatic, single-tendon, full-thickness supraspinatus tear in whom non-operative management had failed were treated with an arthroscopic repair. Preoperative radiographs were used to measure CSA and AI. Eight years postoperatively MRI-studies were performed and evaluated on repair integrity. Patient Reported Outcome Measurements (PROMs) were collected pre- and postoperative.
Results
Thirty-one patients were evaluated 8 years postoperatively. The mean age at time of the surgery was 61 ± 9 years. MRI evaluation showed that 20 (65%) patients had an intact repair and 11 (35%) had a full-thickness retear. No significant differences were found between the intact and retear groups regarding to age (P = 0.605), initial tear size (P = 0.485), retraction grade (P = 0.439) and all PROMs. The mean CSA for the intact group (33° ± 1°) was significantly lower than the CSA in the retear group (38° ± 1°; P = 0.004). The odds ratio of having a retear is 5.50 if the CSA = 35° (P = 0.059). The mean AI for the intact group (0.72± 0.11) was significantly lower than the AI in the retear group (0.81 ± 0.08; P = 0.021). If the AI was = 0.75, the odds ratio of having a retear was 6.19 (P = 0.045).
Conclusion
Also at long-term follow-up, a higher CSA and AI significantly increased the retear risk after arthroscopic supraspinatus tendon repair. A CSA =35° leads to an 5,5-fold increased risk of retear. An AI =0.75 leads to a 6-fold increase in risk of retear after arthroscopic supraspinatus tendon repair.
Shoulder
Glenohumeral
Repair/Reconstruction
Tears
MRI
Outcome Studies
Rehabilition/Physical Therapy
Supraespinoatus Tendon Injury
Tendon
X-ray

### 19852 Arthroscopic posterior tibial nerve neurolysis

Nicolas Baudrier
Alexandre Hardy
Thomas Bauer
France
Summary
Arthroscopic posterior tibial nerve neurolysis
Data
Arthroscopic Posterior Tibial Nerve Neurolysis A. GHABCHA, N. BAUDRIER, A. HARDY, T. BAUER
Introduction
The indications for an ankle arthroscopy is expanding, neuropathy of the tibial nerve could be one of them, the purpose of our study is to discuss the safety and feasibility of the arthroscopic neurolysis of the posterior tibial nerve proximal to the tarsal tunnel.
Materials and Methods
Fourteen lower limbs of seven fresh frozen cadavers were dissected. Posterior tibial nerve neurolysis was done arthroscopically starting 5cm proximal to the medial malleolus until 2cm distal to the medial malleolus (proximal border of the tarsal tunnel) using standards posteromedial and posterolateral arthroscopic portals, then open dissection was done at the same level of the neurolysis to identify any iatrogenic nerve injury, vascular injury or tendon injury. The main judgment criteria were the achievement of the neurolysis of the posterior tibial nerve, the secondary criteria were the presence of any nerve lesion, vascular lesion, flexor hallucis longus lesion.
Results
The Neurolysis of the Posterior Tibial Nerve was successful in 14 ankles, no nerve lesion was noted, we had 1 arterial lesions in 14 ankles (7%), no flexor hallucis longus lesion was observed.
Conclusion
The neurolysis of the posterior tibial nerve proximal to the Tarsal Tunnel can be done Arthroscopically, the risk of the vascular lesion remains high, the procedure should be done by experienced surgeon familiar with ankle anatomy and arthroscopy to minimize this rate. Key Words: Arthroscopic Neurolysis, Posterior Tibial Nerve, Ankle
Ankle/Foot/Calf
Arthroscopy
Nerve
Posterior Tibial Nerves

### 20095 Meniscal procedures are not increased with delayed ACL reconstruction and rehabilitation: results from a randomized controlled trial

Sabine van der Graaff
Max Reijman
Eline van Es
Sita Bierma-Zeinstra
Jan Verhaar
Duncan E Meuffels
Netherlands
Summary
We assessed whether non-operative treatment of anterior cruciate ligament ruptures leads to more meniscal procedures compared to early ACL reconstruction. We found that initial non-operative treatment does not lead to more meniscal procedures compared to early ACL reconstruction over a two-year follow-up period.
Data
Objective
To assess whether initial non-operative treatment of anterior cruciate ligament (ACL) ruptures leads to more meniscal procedures compared to early ACL reconstruction.
Methods
We compared the number of meniscal procedures of 167 patients with an ACL rupture, who either received early ACL reconstruction (n=85) or rehabilitation therapy plus optional delayed ACL reconstruction (n=82), participating in the COMPARE trial. We evaluated the presence and location of meniscal tears by baseline MRI. Meniscal surgical procedures were described per time period: before ACL reconstruction, during ACL reconstruction and after ACL reconstruction till end of follow-up (two years). When no ACL reconstruction was performed, we described all meniscal procedures during the follow-up period.
Results
At baseline 41% of the entire study population (n=167) had a meniscal tear on MRI. During the two-year follow-up 28 meniscal procedures were performed in 25 patients randomized to early ACL reconstruction (29%, 25/85 patients) and 20 procedures in 17 patients randomized to rehabilitation plus optional delayed reconstruction (21%, 17/82 patients) (between group difference 9% with 95% confidence interval −4% to 22%). In patients who received early ACL reconstruction (n = 82) and patients who received delayed ACL reconstruction (n = 41), 5% of the patients had an additional meniscal procedure after ACL reconstruction. In patients who received no ACL reconstruction (n=41), 10% (n=4) had a surgical procedure for a meniscal tear during the two-year follow-up period.
Conclusion
The results of this study suggest that initial non-surgical treatment of ACL ruptures does not lead to a higher number of meniscal procedures compared to early ACL reconstruction over a two-year follow-up period.
Knee
Arthroscopy
Meniscus
Tears
ACL
Instability
Lateral
Ligaments
Medial
Rehabilition/Physical Therapy
Repair/Reconstruction

### 20081 Why, when and who fails non-operative treatment of anterior cruciate ligament injury – an exploratory analysis of the compare trial

Sabine van der Graaff
Duncan E Meuffels
Sita Bierma-Zeinstra
Eline van Es
Jan Verhaar
Vincent Eggerding
Max Reijman
Netherlands
Summary
We investigated why, when and which patients with an anterior cruciate ligament rupture who initially started with rehabilitation therapy eventually required reconstructive surgery. Patients who experienced instability complaints, pain during activity and had a low perception of their knee function were unsuccessful with non-operative treatment.
Data
Objective
To investigate why, when and which patients with an anterior cruciate ligament (ACL) rupture who initially started with rehabilitation therapy required reconstructive surgery.
Methods
In the COMPARE trial, 167 patients with an ACL rupture were randomized to early ACL reconstruction or rehabilitation therapy plus optional delayed ACL reconstruction. We conducted an exploratory analysis of a subgroup of 82 patients from this trial, who were randomized to rehabilitation therapy plus optional delayed ACL reconstruction. The reasons for surgery were registered for the patients who underwent a delayed ACL reconstruction. For these patients we determined International Knee Documentation Committee (IKDC), numeric rating scale (NRS) pain and instability question from the Lysholm questionnaire before surgery. To determine between group differences between the non-operative treatment and delayed ACL reconstruction group, IKDC and pain scores during follow-up were determined using mixed models and adjusted for sex, age and BMI.
Results
During two-year follow-up of the trial 41 of the 82 patients received a delayed ACL reconstruction after a median time of 6.4 months after inclusion (IQR 3.9–10.3). Most reconstructions occurred between three and six months after inclusion (n=17, 41.5%). Ninety percent of the patients (n=37) reported knee instability complaints as reason for surgery at the moment of planning surgery. Of these patients, 18 had an IKDC score below 60, 29 had a pain score of 3 or higher and 33 patients had knee instability complaints according to the Lysholm questionnaire. During follow-up, IKDC scores were lower and pain scores were higher in the delayed reconstruction group compared to the non-operative treatment group. At baseline, patients in the delayed reconstruction group had a significant lower age (27.4 versus 35.3 years, p=0.001) and higher pre-injury activity level compared to patients in the non-operative treatment group.
Conclusion
Patients who experienced instability complaints, pain during activity and had a low perception of their knee function were unsuccessful with non-operative treatment. Most patients received a delayed ACL reconstruction after 3 to 6 months of rehabilitation therapy. At baseline, patients that required reconstructive surgery had a lower age and higher pre-injury activity level compared to patients that were not reconstructed.
Knee
ACL
Failed
Instability
Ligaments