Near infrared spectroscopy in the diagnosis of chronic exertional compartment syndrome

Background: Patients with chronic exertional compartment syndrome (CECS) experience pain during exercise. An abnormal increase in intracompartmental pressure (ICP) leads to impaired local tissue perfusion resulting in ischemia and pain. At cessation of exercise, pain subsides. Diagnosis is confirmed through postexercise ICP. Near infrared spectroscopy (NIRS) can measure tissue oxygen saturation (StO(2)) noninvasively. Hypothesis: NIRS can diagnose CECS by showing tissue deoxygenation. Study Design: Prospective, nonrandomized clinical trial. Method: Volunteers completed a standardized exercise protocol. Those suspected of CECS did so preoperatively and postoperatively. StO(2) and ICP were monitored. Data were compared between volunteers and patients and prefasciotomy and postfasciotomy. Results: Significant differences between the StO(2) values of volunteers and patients with CECS were found. Average peak exercise StO(2) value for those with CECS was lower than for the healthy (27 versus 56, P < .05). Patients showed more absolute and percentage change between baseline and peak exercise StO(2) (absolute: 60 versus 35, P < .05; percentage: 67 versus 38, P < .05). StO(2) values in legs with confirmed CECS returned to normal range postfasciotomy. All changes differed significantly with preoperative values. Conclusion: StO(2) can distinguish healthy from diseased legs. This study provides evidence supporting NIRS as a noninvasive, painless alternative to ICP in the diagnosis of CECS.