Predictors of Improvement After Fasciotomy for Treatment of Chronic Exertional Compartment Syndrome of the Lower Extremity

Abstract

Background:

Previous studies have demonstrated the effectiveness of lower extremity fasciotomies in treating chronic exertional compartment syndrome (CECS). However, not all patients have demonstrated the same level of symptom improvement.

Hypothesis:

Specific patient variables will lead to enhanced functional improvement after fasciotomy for CECS of the lower extremity.

Study Design:

Case series.

Level of Evidence:

Level 4.

Methods:

A review of patients undergoing fasciotomy of the lower extremity for treatment of CECS by a single surgeon from 2009 to 2017 was performed. Pre- and postoperative measures of Foot and Ankle Ability Measure–Sports subscale (FAAM–Sports), FAAM–Sports Single Assessment Numeric Evaluation (SANE), and visual analog scale (VAS) for pain during sporting activities were collected at a minimum of 12 months postoperatively. The primary outcomes of change in FAAM-Sports, FAAM-Sports SANE, and VAS during sporting activities were calculated by taking the difference of post- and preoperative scores. Generalized multiple linear regression analyses was performed to determine independent predictors of functional and pain improvement.

Results:

A total of 61 patients (58% response rate) who underwent 65 procedures were included in this study, with postoperative outcome measures obtained at mean duration of 57.9 months (range, 12-115 months) after surgery. Patients had a mean ± SD improvement in FAAM-Sports of 40.4 ± 22.3 points (P < 0.001), improvement in FAAM-Sports SANE of 57.3 ± 31.6 points (P < 0.001), and reduction of VAS pain of 56.4 ± 31.8 points (P < 0.001). Multiple linear regression analysis revealed deep posterior compartment involvement, younger age, a history of depression, and male sex to be significant independent predictors of enhanced improvement after fasciotomy.

Conclusion:

Fasciotomy is an effective treatment of CECS, with our study identifying certain patient variables leading to greater functional improvement.

Clinical Relevance:

Male patients, younger patients, patients with depression, and patients with deep posterior compartment involvement may serve to benefit more with fasciotomies for treatment of CECS.

Chronic exertional compartment syndrome (CECS) is a cause of exertional pain in many active individuals.^1,2 Exertional leg pain in athletes presents with a wide differential diagnosis, including stress fractures, nerve entrapments, medial tibial stress syndrome, and popliteal artery entrapment, but CECS may cause up to one-third of exertional leg pain in athletes and military personnel.^1,2 The pathogenesis of CECS is caused by a pathologic rise in pressure within a myofascial compartment that occurs as muscle volume increases during activity.^10,11 Commonly, patients will report symptoms of pain during activity that quickly subsides once exercise ends. In addition to pain, patients may report neurologic symptoms such as numbness and tingling.^10,11 Recent studies have identified that the incidence of CECS is increasing in the population, making the understanding of the diagnosis, treatment, and outcomes paramount. ¹⁷

The diagnosis of CECS relies on a thorough history and physical examination. A patient’s history will indicate the timeline of symptom onset and resolution in relation to his or her activities. A strong clinical suspicion typically leads to the diagnosis of CECS. However, as a confirmatory test, pre- and postexercise compartment pressures may be measured. ² However, because of the invasive nature of compartment pressure testing, many patients may choose to pursue activity modification and other noninvasive treatments before undergoing compartment pressure testing. ²

Treatment of CECS involves operative as well nonoperative modalities. Patients typically undergo physical therapy and activity modification prior to surgical intervention. Patients who fail nonoperative treatment may elect to undergo surgical treatment, typically in the form of fasciotomies or other described surgical procedures. Multiple studies have successful outcomes in patients undergoing fasciotomies.^3,6,9 Additionally, recent studies have a high rate of return to athletic endeavors after fasciotomy for CECS. ⁶ However, there is a subset of patients who do not achieve optimal outcomes.^3,6,9 It is unclear what preoperative characteristics are predictive of failure to return to sport or clinically improve.

CECS poses a challenging problem for many patients and surgeons. Many patients are symptomatic and undergo nonoperative treatment for an extended period prior to undergoing surgical intervention. Davis et al ² have reported that it can take more than 2 years for patients to undergo surgical intervention from the onset of symptoms. During this time, patients can see a decline in their physical function and become disgruntled throughout the process. Surgical intervention may be successful in many patients; however, there is a lack of evidence regarding which factors are associated with a successful outcome. The purpose of this study was to identify patient factors that affect the degree of functional improvement in patients undergoing fasciotomies for treatment of CECS.

Methods

We performed an institutional review board–approved retrospective review of patients undergoing fasciotomy of the lower extremity for treatment of CECS by a single fellowship-trained foot and ankle orthopaedic surgeon from 2009 to 2017. Exclusion criteria included patients undergoing revision fasciotomy procedures, patients with concomitant lower extremity conditions requiring surgical intervention at time of prior fasciotomy, and patients undergoing fasciotomy for treatment of acute compartment syndrome. Patient demographic information, including age, sex, body mass index (BMI), duration of symptoms prior to surgery, tobacco use status, comorbidities (diabetes mellitus, depression), type of sport, and level of sport competition was collected via electronic chart review. Preoperative measures of Foot and Ankle Ability Measure–Sports subscale (FAAM-Sports) (range, 0-100), FAAM-Sports Single Assessment Numeric Evaluation (SANE) (range, 0-100), and visual analog scale (VAS) for pain (range, 0-100) during sporting activities were also collected. ⁷

CECS diagnosis was based on a detailed history, clinical examination, and radiographic evaluation, including plain radiographs of the tibia for exclusion of periostitis and stress fractures, followed by preoperative compartmental testing of the anterior, lateral, and deep posterior compartments by 2 experienced nonoperative sports medicine physicians using an intracompartmental pressure monitor (Stryker). Local anesthetic was utilized in the skin, superficial to the fascia, to decrease pain from the pressure testing. Patients underwent preexercise compartmental testing and then were instructed to run on a treadmill for at least 20 minutes, or until the onset of pain, at which point pressures in the 3 compartments were retested to determine postexercise pressures. The superficial posterior compartment was not routinely tested.

For anterior compartment testing, with the patient supine, the anterior border of the tibia was palpated at the level of the junction of the proximal and middle thirds of the lower leg. The needle entry point was 1 cm lateral to the anterior border of the tibia. The needle was oriented so that it was perpendicular to the skin and inserted to a depth of 1 to 3 cm. For the deep posterior compartment, the medial border of the tibia was palpated at the level of the junction of the proximal and middle thirds of the lower leg. The needle entry point was just posterior to the medial border of the tibia. The needle was directed toward the posterior fibular border, while keeping it perpendicular to the skin. The needle was advanced to a depth of 2 to 4 cm, depending on the amount of subcutaneous fat. For the lateral compartment, the posterior border of the fibula was palpated at the level of the junction of the proximal and middle thirds of the lower leg. The needle entry point was just anterior to the posterior border of the fibula. While keeping the needle perpendicular to the skin, it was advanced toward the fibula to a depth of 1 to 1.5 cm.

The Pedowitz criteria were utilized for final diagnosis (Table 1) because of their high sensitivity and positive predictive value, ¹⁰ with diagnosis for CECS being made with appropriate clinical findings in addition to a preexercise compartment pressure of 15 mm Hg or greater, and/or a 1-minute postexercise compartment pressure of 30 mm Hg or greater. ¹¹ Patients underwent either 2- or 4-compartment fasciotomy based on compartmental pressure testing. Those with bilateral symptoms had procedures performed concomitantly or in a staged manner, depending on patient symptoms and/or preference. Procedural variables were confirmed by review of operative reports.

Table 1.

Pedowitz criteria for diagnosis of chronic exertional compartment syndrome

Activity Level	Pressure, mm Hg
Pre-exercise	≥15
1-minute postexercise	≥30
5-minute postexercise	≥20

Fasciotomy was performed utilizing a 2-incision technique to release the anterior and lateral compartments, with 2- to 2.5-cm incisions over the intermuscular septum of the lateral leg. ¹² One incision was performed 10 cm below the knee joint and the other incision was performed 10 cm above the ankle joint, where the superficial peroneal nerve exits the anterior crural hiatus. For the release of posterior compartments, a single 5-cm medial incision was performed in the middle of the tibia and approximately 1 cm posterior to the medial tibial crest. ¹²

Postoperatively, patients were placed in a controlled ankle movement (CAM) boot with instructions to limit their ambulation and use crutches for assistance during the first 2 weeks. Patients were allowed to ambulate in the CAM boot without assistance as well as perform range of motion and stretching exercises at home without the CAM boot from 2 to 4 weeks. At 4 weeks, patients no longer needed to wear the CAM boot at home and were allowed to use an elliptical machine, if available. After 6 weeks, patients were instructed to completely discontinue the CAM boot, with a gradual allowance of higher-level activity, including running.

Patients at least 12 months removed from surgery were contacted via the Research Electronic Data Capture (REDCap) system to complete the FAAM-Sports, FAAM-Sports SANE, and VAS for pain during sporting activity.^4,5 In total, 61 patients undergoing 65 procedures were able to be contacted to complete postoperative outcome measures at mean duration of 57.9 months (range, 12-115 months) after surgery. From 2009 to 2017, 105 patients underwent fasciotomies for CECS, generating a response rate of 58% (61/105).

Statistical Analysis

All statistical analyses were performed using IBM SPSS Statistics for Windows, Version 26 (IBM Corp). The primary outcomes of change (delta, Δ) in FAAM-Sports, FAAM-Sports SANE, and VAS during sporting activities were calculated by taking the difference of post- and preoperative scores. Descriptive statistics were calculated for patient variables and outcome measures. Mann-Whitney U tests were utilized to compare pre- and postoperative score improvement in the entire cohort. Kruskal-Wallis tests were performed for univariate analysis to determine associations between patient variables and change in outcome scores. To determine significant predictors of outcome improvement, a generalized multiple linear regression model with patient variables was created to determine independent predictors of functional and pain improvement. Based on univariate analysis and clinical experience, a regression model of patient variables was developed that included (1) CECS of the deep posterior compartment, as determined by the Pedowitz criteria; (2) duration of symptoms prior to surgery (months); (3) age (years); (4) BMI (kg/m²); (5) sex; and (6) history of depression. Regression coefficients (B) with 95% CI and P values were reported for significant findings. Statistical significance was set at P ≤ 0.05.

Results

Of the 61 patients undergoing fasciotomy for treatment of CECS, 36 (59.0%) were women. The median age was 22 years (interquartile range [IQR], 19-31 years) and the median BMI was 24.4 kg/m² (IQR, 22-30 kg/m²) (Table 2). Our cohort additionally included 2 (3.3%) current smokers and 5 patients (8.2%) with depression. Of the total, 33 (54.1%) patients were considered recreational athletes, while 25 (41.0%) were competitive athletes, participating in high school (n = 9), collegiate (n = 12), or professional level (n = 4) athletics. Three patients (4.9%) were active-duty military personnel. Patients reported a median duration of symptoms prior to surgery of 24 months (IQR, 8-48 months). A summary of preoperative pressure measurements meeting the Pedowitz criteria are listed in Table 3.

Table 2.

Patient demographic variables

Demographic	n (%)
Female patients	36 (59)
Active smokers	2 (3)
Depression	5 (8)
	Median (IQR)
Age, y	22 (19-31)
BMI, kg/m2	24 (22-30)
Preoperative symptom duration, mo	24 (8-48)

BMI, body mass index; IQR, interquartile range.

Table 3.

Pre- and postexercise compartment pressure testing in patients meeting Pedowitz criteria and undergoing fasciotomy ^a

	Preexercise, mm Hg	1-Minute Postexercise, mm Hg
Anterior	21 (18-26)	42 (34-56)
Lateral	19 (16-24)	41 (33-60)
Deep posterior	22 (18-26.5)	38.5 (32-50)

^aValues displayed as median (interquartile range).

Of the 65 procedures, 40 (61.5%) were simultaneous bilateral fasciotomies, 6 procedures (9.2%) performed on 3 patients were staged bilateral fasciotomies, and 17 (26.2%) were unilateral fasciotomies. One patient who was initially unilaterally symptomatic eventually developed symptoms of the opposite side and then underwent a release of the opposite side. Four-compartment fasciotomy was performed 16 times (24.6%), while 49 fasciotomies (75.4%) involved 2 compartments. Twenty patients (22 procedures) involved deep posterior compartment pressures meeting the Pedowitz criteria. There were a total of 5 minor postoperative complications, all of which resolved without additional surgery: 1 incision drainage treated with topical antibiotics, 1 cellulitis treated with antibiotics, 1 deep fascial scar band, 1 common peroneal nerve impingement, and 1 anterior compartment herniation.

Pre- and postoperative functional scores are displayed in Table 4. Patients had a mean improvement in FAAM-Sports 40.4 ± 22.3 points (P < 0.001), improvement in FAAM-Sports SANE of 57.3 ± 31.6 points (P < 0.001), and reduction of VAS pain of 56.4 ± 31.8 points (P < 0.001). Additionally, patients with depression demonstrated a lower median postoperative VAS pain (5.5 vs 15; P = 0.36) and increased median postoperative SANE (98 vs 85; P = 0.30).

Table 4.

Comparison of pre- and postoperative functional measurement scores ^a

	Preoperative	Postoperative	Δ	P
FAAM-Sports	48.7 ± 18.8	89.7 ± 14.8	40.4 ± 22.3	<0.001*
FAAM-Sports SANE	24.0 ± 24.0	82.7 ± 21.7	57.3 ± 31.6	<0.001*
VAS Pain (/100)	78.1 ± 20.7	21.3 ± 24.7	56.4 ± 31.8	<0.001*

FAAM, Foot and Ankle Ability Measure; SANE, Single Assessment Numeric Evaluation; VAS, visual analog scale.

^aValues displayed as mean ± SD.

^*Indicates statistical significance (P ≤ 0.05).

Application of our model on improvement in FAAM-Sports demonstrated that patients with deep posterior compartment pressure meeting the Pedowitz criteria was an independent predictor of increased improvement in FAAM-Sports (14.09 [0.33, 27.86]; P = 0.045) (Table 5). For predictors of improvement in FAAM-Sports SANE, our model demonstrated that patient age (−1.18 [−2.29, −0.07]; P = 0.038), history of depression (39.39 [9.51, 69.28]; P = 0.01), and sex (−26.58 [−47.92, −5.25]; P = 0.02) were independent predictors of improvement, with younger age, history of depression, and male sex all leading to greater improvement in FAAM-Sports SANE after surgery (Table 5). Preoperative duration of symptoms was a marginal predictor (0.14 [−0.00, 0.29]; P = 0.05) of Sports SANE improvement (Table 5). Finally, our model demonstrated history of depression (31.53 [1.71, 61.36]; P = 0.04) to be an independent predictor of greater VAS pain reduction after fasciotomy (Table 5).

Table 5.

Generalized multivariate linear regression of patient variables ^{a , b}

	Δ FAAM-Sports	P	Δ FAAM-Sports SANE	P	Δ VAS Pain	P
Deep posterior compartment involvement	14.09 [0.33, 27.86]	0.05	12.27 [–6.00, 30.53]	0.18	0.23 [–18.29, 18.75]	0.98
Preoperative duration of symptoms	0.08 [–0.03, 0.19]	0.14	0.14 [–0.00, 0.29]	0.05	0.11 [–0.04, 0.27]	0.15
Age	0.02 [–0.82, 0.85]	0.97	–1.18 [–2.29, –0.07]	0.04	−0.50 [–1.59, 0.59]	0.36
BMI	−1.13 [–2.69, 0.42]	0.15	−0.83 [–2.90, 1.23]	0.42	0.22 [–1.77, 2.20]	0.83
Female	−6.64 [–22.72, 9.44]	0.41	–26.58 [–47.92, –5.25]	0.02	12.95 [–6.65, 32.55]	0.19
Depression	16.24 [–5.65, 38.13]	0.15	39.39 [9.51, 69.28]	0.01	31.53 [1.71, 61.36]	0.04

BMI, body mass index; FAAM, Foot and Ankle Ability Measure; SANE, Single Assessment Numeric Evaluation; VAS, visual analog scale.

^aValues reported as regression coefficient [95% CI].

^bSignificant factors for each outcome are in boldface.

Discussion

Symptomatic CECS that is recalcitrant to nonoperative management can be successfully treated by surgical intervention in a large number of patients.^3,6,9 Additionally, patients are able to return to athletic sport at a high level. ⁶ Despite the large number of patients that see significant improvement after surgery, there is a lack of evidence identifying which factors are associated with patient outcomes after fasciotomies for CECS. This investigation identified several factors as predictive of improvement after surgery as identified by the FAAM- Sports, FAAM-Sports SANE, and VAS pain scales.

In this cohort, patients saw significant postoperative improvements in the mean FAAM-Sports, FAAM-Sports SANE and VAS scores from their preoperative baseline. Additionally, using multivariate linear regression, several factors were identified as being independent predictors of a positive outcome. Using the FAAM-Sports SANE after surgery, this study found that a younger age, history of depression, and male sex were all independent predictors of larger score improvement. A history of depression was an independent predictor of greater VAS pain reduction after fasciotomy. A preoperative pressure in the deep posterior compartment consistent with CECS in patients subsequently undergoing fasciotomy including that compartment, was found to be an independent predictor for improved outcome in the FAAM-sports subscore.

Outcome evaluation after fasciotomy has centered around return to sport, military duty, and exercise. In a recent study of 59 patients who underwent fasciotomies for CECS, 93% returned to sport and 76% returned at the same level of competition. ⁶ Packer et al ⁹ evaluated the outcomes of 100 patients that either underwent operative or nonoperative treatment of CECS. In their analysis, a successful outcome was based on each patient’s subjective self-reported satisfaction. Patients had a more successful outcome after surgical intervention compared with patients treated nonoperatively. Additionally, college and high school athletes reported more satisfaction than patients treated after. However, patient-reported outcome scores were not used to objectively compare outcomes. Despite multiple studies showing the efficacy of fasciotomies for treating CECS, not all studies have successful results. Slimmon et al ¹⁴ evaluated the results of 62 patients that underwent partial fasciotomy for CECS at an average follow-up of 51 months. A total of 58% of athletes returned to a lower level of sport and 13% had recurrence of their symptoms.

With depression being predictive of greater improvement, it could be theorized that depression among some patients in our study could have been caused in part by their inability to participate in their desired activities. A return to desired activities may have provided a perceived greater functional and pain improvement in these individuals, causing depressive symptoms to be a positive predictor of SANE improvement after fasciotomy. However, the association of improvement in patients with depressive symptoms may be likely due to the small portion of our cohort with a history of depression, which is a limitation of this study.

Previous studies have evaluated the outcomes of fasciotomies for CECS involving the deep posterior compartment. Rorabeck et al ¹³ compared patients who had CECS of the anterior compartment versus those with isolated deep posterior compartment exertional compartment syndrome. Patients with isolated deep posterior compartment exertional compartment syndrome had significant improvement in symptoms and activity. Winkes et al ¹⁹ evaluated 44 patients that had isolated deep posterior compartment exertional compartment syndrome that underwent fasciotomy, and 47% of patients had good to excellent results based on activity and pain levels at a median follow-up of 27 months. Despite their findings, 76% of their patients reported some relief and said they would have surgery again. Our current study identified that deep posterior compartment involvement and subsequent release was an independent predictor of significant postoperative improvement. This may be due to the high rate of misdiagnosis of deep posterior compartment syndrome, which previous studies have identified may take up to 3 years to properly diagnose. ¹⁸

Military personnel are among groups that are more commonly affected by CECS. Meulekamp et al ⁸ evaluated the success of nonoperative treatment for active military personnel. They identified that 20 out of 45 patients failed nonoperative management, which they defined by improvement in the patients’ overall pain scale rating and running capability. Additionally, no baseline demographics or characteristics were identified as independent predictors of failure of nonoperative management. ⁸ Waterman et al ¹⁷ reported that the incidence of CECS was increasing in the military population. Older military patients, female sex, White race, junior ranking, and service in the U.S. Army were correlated with increased risk of CECS diagnosis. In a follow-up study of 611 patients, perioperative complications, activity limitations, and persistence of preoperative symptoms were predictive of surgical failure. ¹⁶ Furthermore, in the military population 1 out of 5 patients experienced surgical failure.

There are several strengths of this study, including a high-volume tertiary academic medical center. All pre- and postexercise compartment pressure testing was done by 1 of 2 board-certified sports medicine physicians. Additionally, this is among the largest cohorts with an average follow-up of 58 months. However, there are several limitations of this study, including that it is retrospective in nature dependent on preoperative scoring and information based in the medical record. The range of follow-up among patients may have affected their reported outcomes based on changes in functional demands and activities. Though a large number of patients were included in the current study, our follow-up response rate was 58%. It is possible that many of those lost to follow-up had unsatisfactory functional outcomes, which would skew our current results. Additionally, all patients in this study were diagnosed using the Pedowitz criteria for pre- and postexercise testing. Previous studies have identified alternative means for diagnosis that may lead to differences in outcomes from this cohort. ¹⁵ Last, it should be noted that our study includes a large number of patients treated in a short period of time by a single surgeon specializing in surgical treatment of CECS, which may not be representative of the true frequency that surgeons and other providers may encounter this diagnosis. All clinicians must rely on a detailed history, radiographic evaluation, and clinical examination to achieve a high level of clinical suspicion for this diagnosis.

In conclusion, CECS remains a challenge for patients and physicians as it is among the causes of exertional leg pain in young athletes and military personnel. However, the majority of patients who require surgical intervention after failing nonoperative treatment see postoperative improvement. Deep posterior compartment involvement, younger age, a history of depression, and male sex were independent predictors of enhanced improvement after fasciotomy in this analysis, and clinicians should consider these factors when counseling patients regarding postoperative expectations after fasciotomy for CECS.