Calcaneal Apophyseal Fracture Followed by Subtalar Joint Instability in a Young Female: A Case Report

Calcaneal apophyseal fractures are usually considered sport-related injuries. Previous repetitive microtrauma has been proposed as a predisposing factor for such injuries. However, unlike previously reported cases, in our patient, the fracture resulted from acute trauma after stepping on uneven ground. Although the first treatment option for such cases is closed reduction, most cases will require surgical treatment. Furthermore, lesions accompanying this injury have not been sufficiently considered. We report the case of a 9-year-old female with a calcaneal apophyseal fracture treated by fixation of the avulsed proximal part of the apophysis using Kirschner wires and a cerclage wire. However, subsequently, instability developed in the subtalar joint. Fifteen months after the first osteosynthesis, surgery was performed to fixate the subtalar joint and secure the insertion region of the tendo calcaneus. After the first surgery, subtalar joint instability might have developed because of simultaneous disruption of the subtalar ligaments at the initial injury. Subsequently, the instability could have caused failure of the first fixation. Debridement and fixation of the subtalar joint in the second surgery provided a stable subtalar joint. A calcaneal apophyseal fracture might be associated with additional injuries at the hindfoot. Before treating these cases, other injuries that might be obscured by the more apparent injuries should be considered. Accompanying soft tissue injuries, such as subtalar joint ligament lesions, can be revealed with magnetic resonance imaging evaluation. To the best of our knowledge, this is the first report of an apophyseal fracture of the calcaneus followed by subtalar joint instability.