Subtalar dislocation of the foot

We studied a series of seventeen cases of subthalar dislocation of the foot. There were one anterior, twelve medial, and four lateral dislocations. Of the seventeen dislocations, fourteen were closed and three, open. Two of the four lateral dislocations were open. Associated fractures involving the talocalcaneal or talonavicular joints were noted in eight feet, including three of the four with a lateral dislocation. In two feet these fractures were noted only on post-reduction polytomography. Associated factures of the ankle mortise and of the metastarsals were present in seven feet. Associated fractures involving the subtalar or talonavicular joints, open dislocations, and associated injuries requiring immobilization of the foot for more than three weeks produced poor results due to pain and limitation of subtalar motion. Lateral dislocations were particularly prone to poor results, due to the frequency of open injuries and associated fractures. Cast immobilization for three weeks and early range-of-motion exercises of the subtalar joint are recommended for the best results.