FEASIBILITY OF NEAR-INFRARED-SPECTROSCOPY IN THE DIAGNOSIS CHRONIC ANTERIOR COMPARTMENT SYNDROME

Patients with chronic compartment syndrome (CCS) experience pain during exercise. At cessation of exercise, pain subsides within minutes. Supposed aetiology is that exercise causes abnormal increase in intramuscular pressure, impairing local tissue perfusion, resulting in ischemia and pain. Besides clinical findings, diagnosis is confirmed through intra-compartmental pressure (ICP) post-exercise. With near infrared spectroscopy (NIRS) tissue oxygen saturation (StO2) can be measured in a noninvasive manner. Patients with chronic exertional compartment syndrome have shown greater deoxygenation. PURPOSE To determine a difference in StO2 between healthy volunteers and military men with suspected CCS. METHODS Those who met criteria for CCS at a first visit (ICP ≥ 35 mmHg post-exercise), completed a second visit after fasciotomy, volunteers had just one visit. Subjects performed a standardized exercise protocol at each visit. StO2 was monitored continuously in the tibialis anterior muscle of both legs throughout the exercise. StO2 data were compared between patients and volunteers. Pre- and post-fasciotomy StO2 was compared for patients RESULTS A significant difference between StO2 of volunteers compared with CCS was found for: peak exercise value (p = 0.0002), absolute (p = 0.0050) and percent change (p = 0.0011) between baseline and peak exercise StO2, and recovery StO2 as a percent of baseline (p = 0.0211). Average peak exercise value for volunteers was higher than for those with CCS. Healthy volunteers showed less change between baseline and peak exercise. The StO2 values in legs with confirmed CCS returned to the normal range post-fasciotomy. All changes differed significantly with pre-operative values. CONCLUSION StO2 was comparable to ICP in distinguishing healthy from diseased legs. This study provides compelling evidence supporting NIRS as a non-invasive, painless alternative in the diagnosis of CCS. Supported by Hutchinson Technology Inc. BioMeasurement Div., Hutchinson, MN USA