Post-Exertional MRI Is Useful as a Tool for Diagnosis and Treatment Evaluation for Chronic Exertional Compartment Syndrome of Forearms.

Chronic exertional compartment syndrome (CECS) is a rare condition, which generally occurs in athletes. Few tools are available for diagnosis and treatment evaluation. We examined pre- and post- exertional forearm magnetic resonance imaging (MRI) before and after fasciotomy since 2013. The purpose of this study was to evaluate the efficacy of pre- and post-exertional MRI before and after fasciotomy. We treated 8 forearms of 5 patients diagnosed with CECS of the forearms since 2013, including 6 forearms of 3 motocross racers, 1 forearm of 1 baseball pitcher, 1 forearm of 1 manual laborer with a history of muscle contusion. We obtained pre- and post-exertional MRI before and after fasciotomy in all cases. Pre-exertional MRI was obtained when the patient was at rest without any symptom. Post-exertional MRI was obtained after the patients repeated "grip and release" using a hand gripper with maximum effort for approximately 10 minutes until symptoms occurred. We compared MRI findings before and after fasciotomy and evaluated the correlation with clinical outcome. Symptoms disappeared completely in all 3 motocross racers after fasciotomy. MRI at rest showed no abnormal high signals in all cases both before and after fasciotomy. On post-exertional MRI, T2 high area presented mainly in flexor digitorum profundus (FDP) and brachioradialis (BR) and disappeared completely after surgery. Symptoms persisted in the pitcher and the laborer after fasciotomy. T2 high area presented mainly in FDP on post-exertional MRI before fasciotomy and remained on post-exertional MRI after fasciotomy in these two patients. These intensity changes correlated strongly with their symptoms. We performed pre- and post-exertional MRI before and after fasciotomy. The intensity change in T2-weighted images on post-exertional MRI correlated strongly with their symptoms. Post-exertional MRI is useful for diagnosis and treatment evaluation in CECS.