A dislocation of the talus can be a total dislocation or a subtalar dislocation. There are two different main types of dislocations, total and subtalar. Subtalar dislocations are further categorized into lateral and medial dislocations.
A total dislocation of the talus that is not accompanied by a fracture is a very rare injury. Most of the injuries are open and urgent care is necessary in order to avoid any soft tissue complications. There is a high risk of avascular necrosis of the talus, as well as arthritis and soft tissue infection.
Subtalar dislocations of the talus are rare injuries that result from either excessive supination or from excessive pronation. It involves a simultaneous dislocation of the distal articulations of the talus at the talocalcaneal and talonavicular joints. A lateral subtalar dislocation is often the result of a high energy trauma. These dislocations have a worse long-term prognosis. Irreducible lateral dislocation due to interposed tibialis posterior tendon. Lateral subtalar dislocations can be unstable and may sublux. The physician may need a CT scan to check for fractures. 85% of the dislocations are medial and often result from low energy trauma. Irreducible medial dislocations can be due to the interposed extensor digitorum brevis or extensor retinaculum. The direction of subtalar dislocation has important effects with respect to management and outcome. Complications of subtalar dislocations may include stiffness and subtalar arthritis.
Stable dislocations will be treated with a closed reduction. The patient should have 3-4 weeks of immobilization, followed by physical therapy. Unstable fractures will require a closed reduction; an internal fixation may be required. An anteromedial incision is used for medial dislocations and a lateral approach is used for lateral dislocations.