Talar neck fracture associated with talonavicular dislocation and fracture of posteromedial process of talus.

Canale and Kelly modified the Hawkins classification of talar neck fractures by adding a type IV fracture dislocation to the original 3 types described. Type IV injury occurs rarely and is the only type involving dislocation of the talonavicular joint. To our knowledge, only 2 unusual cases have been described in published studies in which a fracture of neck of the talus occurred in association with talonavicular dislocation but the ankle and subtalar joints remained intact. We describe a very unusual case of an adult male with a fracture of the neck of the talus with talonavicular dislocation, subtalar subluxation, an intact ankle joint, and a fracture of the posteromedial tubercle of talus. Open reduction and internal fixation of the talar neck and posteromedial tubercle was undertaken. The talar neck fracture united without any evidence of avascular necrosis, but the posteromedial tubercle remained un-united. Such an injury is unusual, and the injury pattern is unique and cannot be classified using existing systems.