Chronic exertional compartment syndrome is frequently diagnosed through static compartment pressure measurements and managed with fasciotomy: A systematic review

Objectives: Chronic exertional compartment syndrome (CECS) can be diagnosed either clinically or with intra-compartmental pressure monitor measurements and can be treated surgically or conservatively. Methods: A systematic review was performed on diagnostic and treatment modalities for CECS. Included studies were those that reported both their speci ﬁ c diagnostic modality and treatment regimens. Both surgical and conservative treatment strategies were considered. Demographic variables, diagnostic modalities, patient satisfaction and return to sport, the number of surgical incisions used for the anterior compartment fasciotomy, and the speci ﬁ c conservative treatment regimens were also recorded. Diagnostic modalities were grouped into one of three groups: 1) static compartment pressure monitor, 2) dynamic pressure monitoring, and 3) strictly clinical diagnosis. Results: The literature search identi ﬁ ed 373 studies, of which 29 were included for ﬁ nal analysis. In total, there were 1270 total patients. Twenty-four studies used static compartment pressure monitors, 5 studies used dynamic pressure monitors and 2 studies used a strictly clinical diagnosis. Surgical management with fasciotomy was performed in 25 studies with a total of 1018 patients, while conservative management was used in 252 patients in 9 studies (5 studies included surgical and conservative treatments). Among surgical studies, 15 used a single-incision technique for anterior compartment fasciotomy, while 6 used a 2-incision technique. The reported satisfaction after fasciotomy was 42 – 94% while the return to sport was 26 – 100%. The reported return to sport in conservative management studies was 25 – 35%. Conclusion: This systematic review found that the majority of clinical reports utilize static compartment pressure measurements to diagnose CECS, with


Introduction
Chronic exertional compartment syndrome (CECS) is a complex pathology associated with overuse in young and athletic populations [1].It can affect both the upper and lower extremities and is characterized by an exercise-induced sensation of tightness, cramping, weakness, paresthesias, and pain [2].Previous studies have reported that CECS is a common cause of chronic leg pain in the athlete, with a reported incidence of 27-33% [3,4].
The exact pathophysiology underlying CECS is not well understood.However, the most commonly accepted theory suggests that there is an exercise-induced increase in blood flow to a muscle, causing it to expand beyond the elastic capacity of the local osteo-fascial compartment.As the intramural pressure rises, it causes compression of the local vessels and nerves, leading to the aforementioned symptoms [2].The most commonly affected location in the lower extremity is the anterior and lateral compartments (>95%), followed, less frequently, by the deep posterior compartment and superficial posterior compartments [5,6].While the diagnosis is frequently made based on clinical symptoms, the gold standard diagnostic modality remains intra-compartment pressure measurements, despite its invasive nature [7,8].
The treatment for CECS typically begins with a course of nonoperative management, including gait re-training focused on a forefoot running protocol, deep tissue massage, and activity modification focused on limiting inciting or symptom-inducing activities [9].However, when symptoms persist, surgical management with fasciotomy can be performed with an open, minimally invasive, or endoscopic technique [10].
The current study sought to perform a systematic review of the literature on CECS and report the most commonly utilized diagnostic modalities and treatment options.The authors hypothesized that intracompartmental pressure measurements would be the most commonly utilized diagnostic tool and that fasciotomy would be the most commonly utilized treatment modality.

Methods
A systematic review of articles was completed using PRISMA (Preferred Reporting Item for Systematic Reviews and Meta-Analyses) guidelines on the diagnosis and treatment of CECS of the lower extremity.The databases used were PubMed and the Cochrane Library.The query was performed in August 2022.The search terms used were "Exertional compartment syndrome" AND "Diagnosis" OR "Management" OR "Treatment" OR "Surgery".
The inclusion criteria consisted of English-language studies on CECS of the lower extremity.Only studies that reported both the specific diagnostic criteria for CECS and the treatment modality used once the diagnosis was made/confirmed were included.Additionally, studies were required to provide the specific diagnostic modalities used (i.e.method for compartment pressure measurements and threshold pressures used to confirm a positive test).Studies that included surgical, conservative, or both types of treatments were included in the final analysis if the specific treatment modality or protocol was described.Exclusion criteria were studies published before 2000, failure to describe the specific CECS diagnostic criteria used, failure to describe the ultimate treatment modality used, revision surgery for CECS, and CECS of the forearm/upper extremity.Additionally, systematic reviews, course lectures, case reports (level V evidence), and review articles were also excluded.Two investigators (initials blinded for review) independently reviewed the abstracts from all identified articles.When necessary, fulltext articles were obtained to allow further application of the inclusion and exclusion criteria.Additionally, reference lists from the included studies were reviewed to verify that all eligible studies were appropriately considered.

Data collection
The variables of interest that were extracted from each study included the number of patients diagnosed with CECS, the number of patients with bilateral CECS, patient age, specific compartments diagnosed with CECS, the diagnostic modality used, and the treatment modality.Diagnostic modalities were grouped into one of three groups: 1) static compartment pressure monitor, 2) dynamic pressure monitoring, and 3) strictly clinical diagnosis.Additionally, the exercises used to work up CECS and the pressure thresholds used to confirm a diagnosis of CECS were recorded.The number of patients considered a failure after a given intervention was recorded as well as the average patient satisfaction and rate of patient return to sport for each study, when available.Finally, the number of surgical incisions used for the anterior compartment fasciotomy and the specific conservative treatment regimens were also recorded.Because the anterior compartment is the most commonly affected compartment and the variability in the number of incisions used during fasciotomies, this was the only compartment that was considered in the surgical technique, number of surgical incisions, portion of the review (Fig. 1) [5,6].
Microsoft Excel was utilized for all statistical analysis.The number of studies that utilized each diagnostic modality and treatment technique was the primary strategy used to test the hypothesis.Risk of Bias.
The risk of bias was also assessed using the Methodological Index for Non-Randomized Studies (MINORS).This tool includes 12 questions to assess quality, 4 of which are only applicable for those studies that are comparative.Each of the 12 items was scored 0 to 2; 0, not reported; 1, was reported but reported or performed poorly or inadequately; 2, reported accurately and well described.Higher scores are associated with a lower risk of bias.Scores !75% were considered high quality with low risk for bias; scores between 50 and 75% were considered medium risk for bias; scores with 50% were considered high risk for bias.For noncomparative studies, the maximum score was 16, while the maximum score for comparative studies was 24.

Results
The systematic review of literature identified 373 studies, of which 29 were included in the final analysis (Table 1; Fig. 2).The average age ranged from 19 23 -36 16 .All but 4 studies [11,12,13,14] reported the specific compartments diagnosed with CECS; there were a total of 578 patients with anterior CECS, 160 with lateral compartment CECS, 110 with deep posterior CECS, and 37 with superficial posterior CECS.

What are the new findings?
This study provides a comprehensive review of literature on chronic exertional compartment syndrome.It reports that the majority of studies use intra-compartmental pressure measurements and surgical treatment strategies.This review can help clinicians understand the process of diagnosis and management of this often-missed pathology.
What is already known?Chronic exertional compartment syndrome is an often-missed diagnosis with a variety of different diagnostic and treatment modalities.Some clinicians argue that it is a strictly clinical diagnosis while others advocate for an objective diagnosis based on intracompartmental pressure measurements.Additionally, this pathology has previously been managed either surgically or conservatively.
The most common diagnostic modalities used were static measurement compartment pressure monitors which were used in 24 studies.Five studies [33,19,13,21,30] used dynamic pressure monitors during exercise regimens.Two studies [27,28] used strictly clinical diagnosis based on history and clinical exam.Among studies that measured compartment pressures, the most commonly utilized diagnostic intra-compartmental pressure thresholds were those described by Pedowitz et al. [8] (n ¼ 14, 54%).These thresholds are >15 mmHg resting, >30 mmHg 1 min after exercise, or >20 mmHg 5 min after exercise.Twenty-six studies reported their specific exercise regimen used to induce a diagnosis of CECS.Twenty-one studies required their patients to complete some form of strictly running or inclined walking regimen (17 were treadmill-based routines), while 4 studies [16,23,12,27,20] obtained measurements/diagnosis after participating in sports.

Discussion
The primary finding of the current study was that the majority of studies used either static or dynamic intra-compartment pressure monitors to diagnose CECS.Additionally, this study shows that surgical fasciotomy using a single-incision approach for the anterior compartment was the most common treatment modality utilized by the included studies.These findings offer sports surgeons crucial insights into the most common diagnostic and treatment modalities for CECS, a historically poorly understood pathology that is commonly misdiagnosed on initial presentation.
Static compartment pressure monitors were the most utilized diagnostic modality while dynamic pressure monitoring systems were the second most commonly used.Static monitoring systems take measurements at single instances in time.This technique may not accurately reflect peak or true compartment pressures and typically requires multiple needle insertions, each associated with its own morbidities [39].Conversely, dynamic monitors allow clinicians to track pressures in a continuous fashion with only one needle insertion per compartment during diagnostic testing.Furthermore, historical studies have demonstrated that changes in pressure may only come about when certain activities are performed and that adherence to certain protocols may not cause pressure changes [40].For these reasons, dynamic pressure monitoring using previously established protocols is considered the gold standard for diagnosing CECS, while static intra-compartmental testing is considered a capable, yet cheaper, alternative diagnostic modality [41,42].
A recent pre-clinical study reported that 40% of compartment measurements using a static measurement technique were greater than 5 mmHg different than the true pressure reported in a cadaveric model [43].Additionally, a study from Merile et al. found that the dynamic pressure monitor MY01 was 600% more accurate than commonly used static monitors in a rat model on acute abdominal compartment syndrome [39].Conversely, a recent study by Vogels et al. reported no difference in accuracy between 4 commonly utilized static and dynamic techniques [44].Beyond clinical diagnosis, the literature review identified several modalities that were not included in the final analysis, such as magnetic radiographic imaging [45], near-infrared spectroscopy [14], and a wireless sensor system with finite element analysis [46].With respect to clinical diagnosis, it can be challenging to negate the inherent subjectivity and variability of the diagnosis as each patient has a unique sensitivity to pain and the ability to obtain specific ankle positions that are known to increase compartment pressures [47,48].While the potential utility of these modalities is intriguing, the accuracy and reproducibility of these techniques are yet to be elucidated in the literature.As such, the current authors would advocate against their clinical use and would support dynamic pressure monitoring as the definitive diagnostic tool when possible.
The majority of studies included in the final analysis performed fasciotomies of the affected compartments in all patients, while the remaining studies utilized conservative management including botulism toxin, microdialysis, and a controlled running program.Within the surgical studies included there was a dichotomy between studies that performed single-incision fasciotomies and those that performed double-incision fasciotomies for the anterior compartment [5,6].This was identified as an important differentiation because the anterior compartment is the most frequently involved compartment [49].An additional factor to consider when choosing a single-incision technique is the use of an endoscope which can help provide direct visualization of a complete fascial release through a minimal incision [50].While the current authors were unable to compare these techniques in this systematic review, both single and double-incision fasciotomy have reported successful outcomes with effective and complete compartmental release [51,33,52].The two techniques are associated with similar complications of inadequate fascial release, persistent pain and symptoms, recurrent fibrosis, and iatrogenic nerve damage [1].Post-operative recurrence can be complex problem which can be managed with partial fasciectomy (1 cm segmental resection), nerve decompression, in addition to possible revision fasciotomy; however, outcomes following these procedures are rarely reported in the literature [53,54].As such, the current study and the level V study from Scully et al. call for future comparative studies designed to compare single vs double-incision techniques and those techniques that use endoscopy to aid in the fascial release [55].
Finally, four studies utilized both operative and conservative treatments [17,24,32,9], with three of these studies comparing these two management approaches [24,32,9].Packer et al. offered patients the choice of conservative vs operative management with fasciotomy and reported higher satisfaction and a greater percentage of patients considered to have a successful outcome with surgical management [24].Similarly, Vogels et al. and Thien et al. reported decreased patient-reported pain and improved patient-reported outcome scores with surgical management [56,32,9].A previous systematic review by Vogels et al. reported higher rates of return to activity and satisfaction with surgical management of CECS.Other studies advocate for conservative treatment of CECS prior to surgical intervention [57,58].Zimmermann et al. reported that nearly two-thirds of soldiers were able to return to active duty with conservative management with gait re-training [58].As such, there appears to be sufficient evidence to justify a full course of conservative management prior to surgical intervention.However, should conservative management fail, the literature provides encouraging outcomes following fasciotomy.
Despite the success of the current systematic review, it is not without limitations.The first limitation is that evaluation of patient outcomes was not a primary consideration in this review, which made it difficult to compare the various treatment modalities.For example, we were unable to demonstrate the superiority of surgical management over conservative modalities.However, this was not the primary aim of the current analysis.Additionally, the specific fasciotomy techniques varied across studies making it difficult to succinctly describe the surgical technique.As such, the current authors deemed it most pertinent to report the number of incisions for the anterior compartment fasciotomy because it was the most commonly involved compartment.Finally, because of the nature of systematic reviews, we were unable to control for confounding variables including, measurement and sampling bias.

Conclusion
This systematic review found that the majority of clinical reports utilize static compartment pressure measurements to diagnose CECS, with fewer studies using dynamic intra-compartment pressure monitors.Additionally, surgical fasciotomy using a single-incision technique was the most common treatment strategy for anterior compartment CECC, with some studies reporting success with the two-incision technique.

Declaration of competing interest
The authors declare the following financial interests/personal relationships which may be considered as potential competing interests.Brian Waterman reports a relationship with American Academy of Orthopaedic Surgeons that includes: board membership.Brian Waterman reports a relationship with American Orthopaedic Society for Sports Medicine that includes: board membership.Brian Waterman reports a relationship with American Shoulder and Elbow Surgeons that includes: board membership.Brian Waterman reports a relationship with Arthrex Inc that includes: consulting or advisory, funding grants, and speaking and lecture fees.Brian Waterman reports a relationship with Arthroscopy Association of North America that includes: board membership.Brian

Fig. 1 .
Fig.1.This image depicts the 2-incision technique used for an anterior and lateral compartment release for chronic exertional compartment syndrome.The distal incision is made 8-12 cm proximal to the tip of the fibula in order to identify the superficial peroneal nerve.An additional incision is made near the proximal tibia-fibula joint to help ensure a complete fascial release.

Fig. 2 .
Fig. 2.This image shows the PRISMA (Preferred Reporting Item for Systematic Reviews and Meta-Analyses) flow chart for the current systematic review.

Table 1
This table describes the demographic information and variables of interest among studies included in the systematic review.

Table 2
This table shows the specific patient outcomes reported for each study.

Table 3
Quality assessment using methodological Index for Non-randomized Studies (MINORS).