Comminuted fracture of the calcaneus associated with subluxation of the talus.

Two cases of complex fracture dislocation of the calcaneus having an unusual pattern of injury are described. The cases exhibit the following special characteristics: (1) fracture dislocation of the calcaneus where the primary fracture line separates the calcaneus into an anteromedial fragment that maintains its normal relationship to the talus and a posterolateral fragment that is dislocated from the subtalar joint. This posterolateral fragment moves laterally and lies adjacent to the fibula; (2) a secondary fracture line separating the lateral portion of the posterior facet from the tuberosity of the calcaneus. Both fragments are dislocated from their normal anatomical position; (3) talar tilt as shown on AP view of the ankle caused by inversion of the talus due to rupture of the lateral collateral ligament. Also, the posterolateral fragments impinging on the fibula pushes the heel downward and contributes to the talar tilt; (4) involvement of the calcaneocuboid joint; (5) dislocation of the peroneal tendons. This fracture pattern is unusual and has not been described before. Recognition of this unusual injury with subsequent and proper management may prevent major disability to the patient. Conservative treatment by casting or early range of motion is contraindicated. Closed reduction should be attempted immediately, and if not successful, a lateral approach with open reduction and internal fixation is the treatment of choice for this complex injury.