Pure subtalar dislocations: About 7 cases and a review of the literature

Isolated acute traumatic subtalar dislocations are fairly rare. They correspond to the talar luxation, including the talonavicular and subtalar joints. The aim of this study was to evaluate the functional and radiological outcomes of conservative treatment after pure subtalar dislocation. The current retrospective study included 7 patients who had an isolated subtalar dislocation over a 5-year period. Of the 7 cases, 6 (85.7 %) had medial dislocations and 1 (14.28 %) had lateral dislocations. All patients underwent immediate closure reduction under anesthesia, followed by immobilization. No open reduction was needed. The mean follow-up was 38.2 months (range 23–53 months). The American Orthopedic Foot and Ankle Society ankle hindfoot mean score was 83 out of 100 points (range 71–91 points). Subtalar mobility was decreased in 3 patients (42.8 %). Subtalar osteoarthritis was seen in 1 case (14.28 %). There were no cases of avascular necrosis of the talus. Published data show that the prognosis for isolated acute traumatic subtalar dislocation is favorable. Medial dislocations are more common than lateral dislocations. Emergent closure reduction allows the removal of soft tissue injuries. The risk of posttraumatic subtalar osteoarthritis is significant, even in the absence of an initial subtalar lesion. Computed tomography after reduction allows the diagnosis of osteochondral lesions.