Traumatic dislocations of the peroneal tendons.

Traumatic dislocation of the peroneal tendons is an often unrecognized injury which has been reported to occur most commonly during snow skiing. The strength of the peroneal retinaculum is exceeded during resistance to violent passive dorsiflexion or to inversion stress. Pain, swelling, and ecchymosis may hinder early diagnosis; however, intense retromalleolar pain on active eversion is a specific, highly suggestive finding. Fracture of a thin shell of the lateral malleolar cortex is diagnostic. In chronic cases, marked dislocation of the tendons is frequently demonstrable, with more than the usual degree of snapping. Surgical repair is advocated, using one of several procedures available. Most acute cases can be treated by simple repair of the torn or fractured structures. In chronic cases, or in acute cases with deficient structures predisposing to dislocation, it is necessary to reconstruct the peroneal retinaculum and/or deepen the peroneal groove. Longitudinal splitting of the peroneus brevis tendon was a new finding in this series.