Recurrent dislocation of the peroneal longus tendon as a complication of multiple osteochondromatosis

This is a report of recurrent dislocation of the peroneal tendon in a patient with multiple osteochondromatosis. The distorted anatomy at the ankle from the osteochondromas was the source of the tendon's recurrent dislocations. There were two areas in the ankle in which the retinacula supporting the tendons failed because of the osteochondromas. At the lateral site of fibula, the origin of the supporting retinacula was attenuated by the presence of an osteochondromas. At the medial site of fibula, a large osteochondroma distorted and widened the tibiofibular joint. The widening of the distal tibiofibular joint by this osteochondromas also attenuated the retinacula of the peroneal tendons, permitting their dislocation.