Chronic Exertional Compartment Syndrome

Introduction

Chronic exertional compartment syndrome (CECS) most commonly affects the young, military, and athletic populations and can be debilitating for active individuals. Typical symptoms include pain, paresthesias, muscle weakness, and discomfort described as squeezing or cramping that occur during exercise and intensify as exertion continues, but disappears when activity stops. Although the specific source of pain in CECS is not entirely understood, the condition is caused by a rise in intracompartmental pressure within an osteofascial space likely related to increased blood flow to muscles during exercise. CECS primarily affects the lower limb, but it can also occur in the thigh, hand, and forearm compartments. Originally thought to be a diagnosis of exclusion, CECS is now thought to be underdiagnosed, and thus increased understanding and awareness of this condition are critical. The symptoms can often be nonspecific, and the broad differential for lower leg pain can interfere with diagnostic clarity.

Owing to the difficulty and delay in diagnosis, the true epidemiology of lower leg CECS in the general population remains unclear. However, incidence rates among athletes and military members have been provided by individual studies, giving an idea of the prevalence of CECS within at-risk populations. In a large population of active military members, Waterman et al. reported an overall incidence rate of 0.49 cases per 1000 person-years. In a different cohort of recreational runners and military members, patients presenting with lower leg pain were evaluated and CECS was diagnosed in 27%–33% of all cases of lower leg pain. Davis et al. confirmed CECS diagnosis in 153 of 226 patients (67.7%; 250 of 393 legs) who presented with the appropriate symptoms and were suspected to have CECS. Among the group with confirmed CECS, 92.2% were active athletes. ^, Worth noting, and discussed by de Bruijn et al. who analyzed CECS in a large, mixed population, CECS is not completely limited to the athletic patient population and can also be found in less active individuals and diabetics.

Anatomy

Compartments are fascia-surrounded groupings of muscles, blood vessels, and nerves categorized by specific anatomic areas in the extremities. The fascia is relatively inelastic, keeping these structures in place and inhibiting stretching and expansion of the compartment space. The lower leg is divided into four compartments: anterior, lateral, superficial posterior, and deep posterior. The anterior compartment consists of the tibialis anterior, extensor hallucis longus, extensor digitorum longus, and peroneus tertius muscles, as well as the deep peroneal nerve and anterior tibial artery and vein. The main functions of the muscles in this compartment are dorsiflexion of the foot and ankle and extension of the toes, as well as inversion and weak eversion of the foot. The lateral compartment includes the peroneus longus and peroneus brevis muscles and the superficial peroneal nerve. These muscles primarily function in eversion of the foot and ankle and secondarily in plantar flexion of the ankle. The superficial posterior compartment comprises the gastrocnemius, soleus, and plantaris muscles and the sural nerve. Finally, the deep posterior compartment consists of the tibialis posterior, popliteus, flexor hallucis longus, and flexor digitorum longus muscles, as well as the posterior tibial artery, peroneal artery, and tibial nerve. The musculature of the combined posterior compartments function in plantar flexion and inversion of the foot.