Also consider claudication with older patients, particularly those who have risk factors for peripheral vascular disease.
Peripheral neuropathy and gastrocnemius/soleus strain are other common diagnoses that are part of the differential. Uncommon yet important diagnoses to consider include osteomyelitis and tumor.
Rare disorders
Though much less common than the above diagnoses, popliteal artery entrapment syndrome (PAES) and peroneal nerve entrapments are important to discuss since their presentations can be almost identical to CCS.
PAES can mimic posterior CCS in presentation and should be part of the differential for any young patient complaining of exertional calf pain. PAES is a rare condition in which the popliteal artery becomes compressed from strenuous exercise, resulting in ischemia. The underlying anatomic anomaly is the relationship of the popliteal artery to the adjacent musculotendinous structures.9 If you suspect PAES, evaluate for a diminished dorsalis pedis pulse with either passive plantar flexion or active dorsiflexion. Patients with exertional calf pain and a positive test result require imaging. These patients should undergo Doppler imaging at rest, with passive plantar flexion, and with active dorsiflexion. Equivocal or incomplete studies require arteriography.10
Similarly, peroneal nerve entrapments can masquerade as anterior/lateral compartment syndromes. While the common, deep, and superficial peroneal nerves can all be entrapped, the superficial branch is most frequently involved.11 The superficial branch exits the lateral compartment approximately 10 cm proximal to the lateral malleolus. Tenderness at this site upon active dorsiflexion, a positive tinel sign at this site, or lateral leg pain upon plantar flexion and inversion all suggest superficial peroneal entrapment.11 Electromyography, oftentimes performed after compartment pressures are found to be normal, is necessary to confirm the diagnosis.
A profile of chronic compartment syndrome
Chronic compartment syndrome was first identified by Mavor in 1956,12 but it was not until 1975 that the disorder’s clinical manifestations and basic pathophysiology were described.13 CCS is an uncommon condition and no published data exist regarding its incidence or prevalence. However, because more physicians are becoming aware of it, CCS is being increasingly recognized. At the University of Wisconsin, the number of patients diagnosed with CCS has more than tripled in each of the last 2 decades.1,2
Athletes most affected. CCS, also known as exertional compartment syndrome or effort-related compartment syndrome, affects primarily young athletes. The mean age of afflicted persons at the time of diagnosis is mid to late twenties. The average duration of symptoms before diagnosis is 2 years.1 The syndrome most commonly affects runners and soccer players, but other sports linked to the development of CCS are cycling, football, gymnastics, and tennis.1,2,3,7 Although the syndrome most commonly affects the lower extremities, many reported cases of CCS have occurred in the forearms and hands.
Young women may be most at risk. Early studies from the United States in the mid-1980s showed that the male to female ratio of affected patients was approximately 1:1.2,8 However, a large, more recent study showed a female-to-male ratio greater than 2:1.1 This likely reflects the increase in female sports participation over the last 2 decades and suggests that females may be at a greater risk of developing the syndrome.
Direct pressure measurement best evaluation
Despite attempts to develop noninvasive testing for CCS, the gold standard remains the direct measurement of intracompartmental pressures. There is some controversy regarding the upper limit of normal, but most authors agree that a resting pressure >15 mm Hg is abnormally elevated.1,2,5 Other cutoffs cited in the literature include a 1-minute post-exercise value greater than 30 mm Hg, and a 5-minute post-exercise reading >25 mm Hg.5 Turnipseed and colleagues recommend checking post-exercise values in patients with modestly elevated resting pressures of 16 to 24 mm Hg to confirm the diagnosis. Because of the pathophysiology of the syndrome, it seems appropriate to also check 5- or 10-minute post-exercise pressures in patients with typical clinical presentations and normal resting pressures.
Orthopedic, vascular, and general surgeons receive training in compartmental pressure measurement. There are 4 techniques for measurement: the simple needle, the Whitesides infusion, the wick catheter, and the slit catheter. Simple needle devices (such as the Stryker stic, FIGURE 2) have increased in popularity because they are handheld, portable, contain a scale within the device for direct measurement, and are easily operated in a clinic setting.14
Diagnostic tools that may yet prove useful
Many other diagnostic modalities have been studied in the last 10 years and may eventually prove helpful. Near infrared spectroscopy has demonstrated a relative deoxygenation during exercise in CCS patients and a delayed reoxygenation in the immediate post-exercise period.15