Treatment of Atraumatic Subtalar Dislocations in Adult Acquired Flatfoot Deformity

Abstract

Category: Hindfoot Introduction/Purpose: There is a subset of patients with adult acquired flatfoot deformity (AAFD) in which the deformity has progressed so much that the subtalar joint is dislocated, causing subfibular impingement. These patients can be technically difficult to treat operatively given the loss of soft tissue and articular constraints. Additionally, they tend to have increased rates of reoperation. We sought to describe the common patient characteristics and the reasons for reoperation in this population through our case series of 23 patients. Methods: A retrospective chart review was done of all patients who underwent surgical correction of AAFD with subtalar, double, triple, or pantalar arthrodesis based on the treating surgeon’s discretion. This review then used radiographic criteria to identify those patients who qualified as having subtalar dislocation on presentation. The charts of qualifying patients were then evaluated for demographic data, comorbidities, complications, and the need for reoperation. Results: We found that the average BMI for patients with this disorder was 34kg/m2 and that of our 23 patients who qualified for the study, 30.4% required reoperation for infection, nonunion, or symptomatic hardware. Conclusion: AAFD is a very common problem seen by foot and ankle surgeons and phyisicans should be aware of the challenges presented in treating the subset of patients who have atraumatic dislocation of the subtalar joint. Patients should also be counseled about the high rate of reoperation with surgical treatment of their AAFD if they fall into this category.