Plantaris muscle injury: evaluation with MR imaging.
OBJECTIVE
To determine the MR imaging appearance of injury to the plantaris muscle.


METHODS
Fifteen patients with sports-related 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 retrospectively examined for abnormalities.


RESULTS
All 15 patients had rupture of the plantaris muscle or strain. An associated torn anterior cruciate ligament (ACL) was found in 10 of 15 patients. Five injuries were isolated or associated with partial tears of the gastrocnemius or popliteus muscle. At initial presentation, three patients had large, focal elongated fluid collections between the medial head of the gastrocnemius muscle and the soleus muscle.


CONCLUSIONS
Rupture of the plantaris muscle may occur at the myotendinous junction with or without an associated hematoma or partial tear of the medial head of the gastrocnemius muscle. A strain of the more proximal plantaris muscle may also occur as an isolated injury or in conjunction with injury to the ACL.
Helms
C A
CA
Department of Radiology, University of California, San Francisco, School of Medicine 94143.
Fritz
R C
RC
Garvin
G J
GJ
D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries; D001265:Athletic Injuries / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000175:diagnosis*; D007869:Leg Injuries / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000293:injuries*; D012189:Retrospective Studies; D012421:Rupture; D013180:Sprains and Strains / Q000175:diagnosis; D013708:Tendon Injuries / Q000175:diagnosis