Lower Limb Chronic Exertional Compartment Syndrome: Procedural Data and Patient Demographics

1. INTRODUCTION

Chronic exertional compartment syndrome (CECS) is a functional musculoskeletal disorder characterized by exercise-induced increases in intracompartmental pressure within a closed fascial compartment, leading to impaired tissue perfusion, pain, and neurological symptoms during physical activity. CECS most commonly affects the lower limb and represents an important cause of exercise-induced leg pain (EILP), particularly in physically active individuals and athletes participating in repetitive high-impact activities such as running, marching, and jumping.^1,2 Symptoms are typically reproducible with exertion and resolve following cessation of activity, although prolonged disease duration may significantly impair athletic performance and quality of life.^2,3

The pathophysiology of CECS is thought to involve transient increases in intracompartmental pressure during exercise, resulting in compromised capillary blood flow and local tissue ischemia.⁴ Patients commonly report aching, cramping, tightness, or burning sensations within the affected compartment after a predictable duration or intensity of exercise.⁵ As symptoms progress, patients are often forced to stop exercising due to escalating pain or neurological dysfunction, including paresthesia and weakness.⁵ These recurrent limitations may contribute not only to physical impairment but also to psychological distress and reduced participation in sport or occupational activities.⁶

Despite increasing recognition in sports medicine and orthopedic practice, CECS remains an underdiagnosed condition due to its non-specific presentation and the broad differential diagnosis of EILP.⁷ Clinical examination is frequently unremarkable at rest, and symptoms may overlap with conditions such as medial tibial stress syndrome, stress fractures, popliteal artery entrapment syndrome, and peripheral nerve entrapment.⁸ Consequently, many patients experience prolonged delays in diagnosis and management, often undergoing multiple investigations and unsuccessful conservative treatments prior to specialist referral.^7,9

Intra-compartmental pressure testing (CPT) remains the current gold-standard diagnostic investigation for CECS.^1,7 CPT involves invasive measurement of resting and post- exercise compartment pressures using a pressure-monitoring device following symptom reproduction.¹⁰ Although several diagnostic criteria have been proposed, interpretation of CPT findings remains controversial, and abnormal pressures do not always correlate perfectly with clinical symptoms.^10,11 Owing to its invasive nature, CPT is generally reserved for patients with a high clinical suspicion of CECS following detailed clinical assessment and exclusion of alternative pathology.⁷

Management of CECS typically begins with conservative strategies, including activity modification, physiotherapy, gait retraining, and non-steroidal anti-inflammatory medications.¹² However, conservative management frequently provides only temporary symptom relief in patients with established disease.¹² Surgical fasciotomy remains the definitive treatment for patients with persistent symptoms and confirmed CECS, with previous studies demonstrating favorable improvements in pain, return to sport, and patient satisfaction following operative intervention.^3,13,14

Although CECS has been increasingly studied in athletic populations, there remains limited UK-based data describing patient demographics, referral pathways, diagnostic yield of CPT, and factors associated with positive diagnostic testing within specialist musculoskeletal centers. Improved understanding of these factors may enhance clinician awareness, optimize patient selection for invasive testing, and reduce delays to definitive management. Therefore, the aim of this study was to characterize the demographics, clinical presentation, diagnostic pathways, and management outcomes of patients referred to for suspected lower limb CECS at a UK specialist national health service (NHS) center, while additionally exploring clinical predictors associated with positive CPT.

2. MATERIAL AND METHODS

3. RESULTS

3.1 Patient demographics

A total of 52 patients were included, with a slightly higher proportion of males (n = 28, 53.8%) than females (n = 24, 46.2%), as shown in Figure 1. The mean age of the cohort was 34.7 ± 12.5 years, reflecting a predominantly young- to-middle-aged, physically active population. Most patients reported bilateral (EILP; n = 41, 78.8%), while 11 patients (21.2%) experienced unilateral symptoms.

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Figure 1: Distribution of patients by gender.

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The majority of patients were male (53.8%), while females accounted for 46.2% of the total sample. This indicates a slightly higher rate among males compared to females, reflecting a relatively balanced gender distribution within the sample.

3.2 Referral sources

Referral patterns prior to CPT are illustrated in Figure 2. The majority of patients were referred by surgeons (n = 33, 62.3%), followed by general practitioners (n = 9, 17.0%), extended scope physiotherapists in musculoskeletal clinics (n = 8, 15.1%), pediatric surgeons (n = 1, 1.9%), and podiatrists (n = 1, 1.9%). This distribution highlights the complexity of the diagnostic pathway for CECS and the reliance on specialist input before invasive testing.

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Figure 2: Referral sources for CECS patients. CECS: Chronic exertional compartment syndrome, GP: General practitioners

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Most referrals originated from surgeons (62.3%), followed by general practitioners (17.0%), and musculoskeletal (MSK) clinics led by extended scope physiotherapists (15.1%). This distribution suggests that patients with CECS are typically referred after multiple assessments, underscoring the diagnostic challenge at the primary care level.

3.4 Imaging and diagnostic findings

Prior to CPT, 75% of patients (n = 39) underwent magnetic resonance imaging (MRI), with a smaller proportion receiving ultrasound (n = 6, 11.5%) or radiographs (n = 7, 13.5%). Following CPT, 43 patients (82.7%) were confirmed to have CECS, while 9 patients (17.3%) had normal compartment pressures and were classified as non-CECS, see Figure 3. This high confirmation rate reflects careful pre-procedural clinical selection.

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Figure 3: CECS diagnosis distribution among patients (n=52). CECS: Chronic exertional compartment syndrome

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82.7% of the total cohort received a confirmed diagnosis of CECS, while 17.3% did not meet the diagnostic criteria. These patients had been pre-screened and pre-selected for CPT via a clinic visit beforehand, where a thorough history and examination were undertaken. The high proportion of confirmed cases highlights the strong clinical suspicion and accurate referral patterns among healthcare providers evaluating EILP.

4. DISCUSSION

This retrospective study provides contemporary insight into the demographics, clinical presentation, diagnostic pathways, and management of patients referred for suspected CECS within a specialist UK musculoskeletal center. The findings demonstrate a high diagnostic yield of CPT, prolonged symptom duration prior to diagnosis, and clinically relevant predictors associated with positive CPT-confirmed CECS, particularly increasing pain severity and bilateral symptom presentation.

CECS remains an important but frequently under- recognized cause of EILP, particularly among physically active individuals and athletes.^1,2 The mean age of patients in the present cohort was consistent with previous studies reporting CECS predominantly in young and middle-aged athletic populations.^2,8 Historically, CECS has often been described as more prevalent in males, particularly within military cohorts and endurance athletes.⁹ However, our findings demonstrated a relatively balanced sex distribution, and male sex was not significantly associated with positive CPT-confirmed CECS. Similar trends have been increasingly recognized in more contemporary literature, suggesting that CECS likely affects both sexes more equally than previously appreciated, particularly in specialist referral settings.^1,2

One of the most important findings of this study was the prolonged delay between symptom onset and definitive specialist assessment, with patients experiencing symptoms for a mean duration approaching five years prior to diagnosis. Delayed diagnosis has consistently been reported within the CECS literature and likely reflects the diagnostic challenges associated with EILP.^5,8 Clinical examination is frequently normal at rest, while symptoms may overlap substantially with stress fractures, medial tibial stress syndrome, vascular entrapment syndromes, peripheral nerve entrapment, and other overuse pathologies.^5,7 As a consequence, patients often undergo multiple investigations and unsuccessful conservative treatments before referral for specialist assessment and invasive testing. Such delays may contribute to prolonged physical limitation, reduced athletic participation, psychological distress, and diminished quality of life.⁶

The anterior compartment represented the most frequently involved compartment within this cohort, consistent with previous biomechanical and physiological studies of CECS.^4,8 Qvarfordt et al. demonstrated that elevated intracompartmental pressures are associated with impaired tissue perfusion and altered skeletal muscle metabolism during exercise, supporting the pathophysiological basis for exertional pain and neurological symptoms in CECS.⁴ Bilateral symptoms were also highly prevalent and emerged as a significant predictor of positive CPT-confirmed CECS in our exploratory regression analysis. Patients with bilateral symptoms demonstrated approximately 3.8-fold greater odds of positive CPT compared with those presenting unilaterally. This finding is clinically relevant, as bilateral exertional symptoms may increase the pre-test probability of CECS and help guide referral decisions for invasive diagnostic testing.

Increasing pain severity was similarly associated with significantly greater odds of positive CPT-confirmed CECS. Each one-point increase in pain NRS was associated with an approximately 2.7-fold increase in the likelihood of positive diagnostic testing. This observation aligns with the established pathophysiology of CECS, whereby elevated intracompartmental pressures during exercise compromise capillary perfusion and provoke ischemic pain.⁴ While pain severity alone should not be considered diagnostic, these findings suggest that symptom burden may assist clinicians in identifying patients most likely to benefit from further specialist investigation.

The diagnostic yield of CPT within this study was notably high, with over 80% of patients demonstrating findings consistent with CECS. This likely reflects careful patient selection within a specialist tertiary referral pathway. Although CPT remains the current reference standard investigation for CECS, controversy persists regarding optimal diagnostic thresholds and the reproducibility of pressure measurements.¹⁰ The Pedowitz criteria remain among the most widely cited diagnostic thresholds; however, variation in methodology and interpretation across studies continues to present challenges.¹⁵ Recent systematic reviews have highlighted growing interest in alternative and adjunctive diagnostic modalities, including dynamic magnetic resonance imaging (MRI), near- infrared spectroscopy, and ultrasound-based techniques.¹⁰ Nevertheless, none have yet demonstrated sufficient evidence to replace CPT as the accepted diagnostic standard.

MRI was commonly utilized prior to CPT in the present cohort. Although MRI is not diagnostic for CECS itself, it remains valuable for excluding alternative causes of EILP, including stress injuries and soft tissue pathology.² The extensive use of imaging prior to CPT likely reflects both the broad differential diagnosis associated with exertional leg pain and the invasive nature of pressure testing. Management strategies in this study were also broadly consistent with current literature. Most patients with positive CPT-confirmed CECS had previously undergone unsuccessful conservative management prior to consideration for fasciotomy. Conservative approaches, including activity modification, physiotherapy, gait retraining, and biomechanical interventions, may provide symptom improvement in selected patients, although success rates remain variable.¹² Surgical fasciotomy, therefore, remains the definitive treatment for patients with persistent symptoms and objective diagnostic confirmation.^2,13

Previous outcome studies have demonstrated favorable functional results following fasciotomy, including improved pain, return-to-sport rates, and patient satisfaction.^3,13,14 Packer et al. reported high levels of postoperative satisfaction following fasciotomy in athletic populations, while more recent systematic reviews and long-term follow-up studies have similarly demonstrated sustained symptom improvement in appropriately selected patients.^3,13,14 Nonetheless, recurrence, residual symptoms, and incomplete return to sport remain recognized challenges following surgery, highlighting the need for careful patient counseling and continued refinement of treatment strategies.^13,14

5. LIMITATIONS

This study has several limitations. First, the retrospective single-center design introduces potential selection and information bias. Second, the relatively small cohort size, particularly the limited number of CPT-negative patients, restricts statistical power and increases the risk of sparse- data bias within regression analyses. Consequently, the exploratory predictive findings should be interpreted cautiously. Third, postoperative functional outcomes, patient-reported outcome measures, and long-term recurrence data were not available for analysis. Finally, despite CPT remaining the accepted diagnostic reference standard, the absence of universally accepted diagnostic thresholds limits comparability across studies and may affect external generalizability. Despite these limitations, this study represents one of the few contemporary UK specialist- center analyses examining diagnostic pathways and predictors of positive CPT-confirmed CECS. The findings highlight the considerable delays patients experience before definitive diagnosis and suggest that bilateral symptom presentation and increasing pain severity may represent clinically useful indicators of true CECS. Improved awareness of these features may help optimize referral pathways, reduce diagnostic delays, and improve patient selection for invasive diagnostic testing and definitive surgical management.

6. CONCLUSION

CECS remains a challenging and frequently delayed diagnosis within patients presenting with EILP. This study demonstrates that specialist clinical assessment combined with CPT provides a high diagnostic yield in appropriately selected patients. Individuals presenting with more severe exertional pain and bilateral symptoms were significantly more likely to demonstrate positive CPT-confirmed CECS, suggesting that these features may represent clinically useful indicators when considering referral for invasive diagnostic investigation. Despite advances in awareness and diagnostic strategies, patients within this cohort experienced prolonged symptom duration prior to definitive diagnosis and management, highlighting the ongoing challenges associated with recognizing CECS in routine clinical practice. Improved clinician awareness, earlier specialist referral, and refined patient selection pathways may help reduce diagnostic delay and facilitate more timely intervention.

Most patients with confirmed CECS proceeded toward surgical management following unsuccessful conservative treatment, reflecting current evidence supporting fasciotomy as the definitive treatment for persistent symptomatic disease. Further prospective multicenter studies incorporating long- term functional outcomes and patient-reported measures are required to optimize diagnostic pathways, refine selection criteria for CPT, and improve overall management strategies for CECS.