Lower extremity compartment syndrome. When to suspect acute or chronic pressure buildup.

Acute compartment syndrome is a surgical emergency. A high index of suspicion is needed in cases of severe contusion, especially if patient complaints seem to outweigh physical findings. Acute surgical fasciotomy is an effective treatment and should be carried out expeditiously if compartment pressures are elevated over 70 mm Hg in order to avoid complications such as chronic disability due to contractures or rhabdomyolysis with acute renal failure. Chronic exertional compartment syndrome most often occurs in the anterior or the lateral compartment. Patients have only exercise-related symptoms and recover quickly after resting from the inciting activity. Diagnosis is difficult, but the anterior compartment pressure may be checked fairly readily with a handheld pressure catheter. Deep posterior compartment problems are harder to check because of the difficulty in reaching this area. Thallium stress testing appears promising for diagnosing both anterior and posterior problems and may augment, or even replace, the catheter measurement in the deep posterior and perhaps even the anterior compartment. Thallium stress testing is noninvasive and may be a more physiologic measurement. Fasciotomy may be indicated if conservative treatment lacks efficacy. For unknown reasons, the deep posterior compartment does not respond as quickly, or as well, to fasciotomy as the anterior compartment.