Surgical Treatment and Management for Chronic Dislocated Subtalar Joint.

Lateral dislocation of the subtalar joint is a relatively uncommon pathology. It has previously been described in the literature secondary to acute trauma. This form of dislocation can also be acquired and seen in severe long-standing cases of flatfoot and Charcot neuroarthropathy. This study aims to describe this "sidecar" deformity, etiologies of the deformity, and the surgical options for correction. This study was performed by reviewing medical records of a single foot and ankle surgeon for patients who met inclusion criteria and underwent surgical correction. The study period was from October 2010 to July 2017. Statistical analysis was performed using chart-review information to examine variables affecting selected outcome measures. The outcome measures evaluated were minor and major complications, as well as functional limb status. A total of 16 patients were included in the study. Etiology included 10 severe flatfoot deformities and 6 Charcot deformities. Seven patients underwent staged reconstruction, and 9 underwent a single-stage reconstruction. Seven patients (44%) had complications; all were major and required unplanned reoperation. In all 16 patients (100%), limb salvage and a functional limb resulted. We conclude that patients with a limb-threatening sidecar deformity can be successfully treated with reconstruction. This is challenging and associated with a high complication rate. Patients with a history of infection should be counseled on the possibility of requiring a staged reconstruction with multiple surgeries as well as the possibility of amputation.