Posteromedial dislocation of the ankle without fracture

We report the results of treatment in eight patients who had posteromedial dislocation of the ankle without fracture. The ages of seven of the eight patients ranged from twenty-three to thirty-six years. Four patients had increased generalized ligamentous laxity. One-half of the injuries were sustained during athletic competition. The mechanism of injury appeared to be forced inversion of the foot when it was maximally plantar flexed and axially loaded. Five of the eight patients had an open injury, and four of the five patients had an associated injury to the anterolateral neurovascular structures. No patient had an injury to the distal tibiofibular ligaments or to the syndesmosis. The three patients who had a closed dislocation achieved good long-term functional and roentgenographic results after closed reduction and immobilization. The patients who had an open injury that was treated by anatomical repair of the disrupted lateral ligaments at the time of initial débridement also achieved good long-term functional and roentgenographic results. It does not appear to be necessary to repair the deltoid ligament. In one patient who had an open dislocation and in whom the lateral ligaments were not repaired, moderate instability of the ankle resulted and degenerative changes developed in the joint.