PLANTARIS MUSCLE INJURY - EVALUATION WITH MR-IMAGING

PURPOSE: To determine the MR imaging appearance of injury to the plant aris muscle. MATERIALS AND METHODS: Fifteen patients with sports-relat ed injuries to the lower leg underwent magnetic resonance (MR) imaging with T1- and T2-weighted, gradient-echo T2-weighted, short inversion time inversion-recovery, and fast spin-echo sequences. The plantaris muscle and tendon, as well as the surrounding structures, were retrosp ectively examined for abnormalities. RESULTS: All 15 patients had rupt ure of the plantaris muscle or strain. An associated torn anterior cru ciate ligament (ACL) was found in 10 of 15 patients. Five injuries wer e isolated or associated with partial tears of the gastrocnemius or po pliteus muscle. At initial presentation, three patients had large, foc al elongated fluid collections between the medial head of the gastrocn emius muscle and the soleus muscle. CONCLUSION: Rupture of the plantar is muscle may occur at the myotendinous junction with or without an as sociated hematoma or partial tear of the medial head of the gastrocnem ius muscle. A strain of the more proximal plantaris muscle may also oc cur as an isolated injury or in conjunction with injury to the ACL.