Pure dislocation of the ankle: three case reports and literature review.

Ankle dislocation without fracture is an extremely rare injury. The results of treatment are reported for three patients who had a posteromedial open dislocation, a lateral open dislocation, and a posterior closed dislocation of the ankle. Management consisted of immediate reduction, debridement and capsular suture in the open dislocations, and immobilization with a short leg cast in all patients. At followup no patient had tibiotalar joint instability; a 10 degrees to 15 degrees loss in the range of dorsiflexion was observed in two patients. One patient reported paresthesia in the area of the superficial peroneal nerve. The three patients achieved good long-term functional and radiographic results. Predisposing factors that contribute to the pathogenesis of this lesion are internal malleolus hypoplasia, ligamentous laxity, weakness of the peroneal muscles, and previous ankle sprains. Among the three patients, medial malleolus hypoplasia was present in one patient and previous sprains were seen in the clinical history of another patient.