Plafond Malreduction and Talar Dome Impaction Accelerates Arthrosis After Supination-Adduction Ankle Fracture

Background: Supination-adduction (SAD) type II ankle fractures can have medial tibial plafond and talar body impaction. Factors associated with the development of posttraumatic arthritis can be intrinsic to the injury pattern or mitigated by the surgeon. We hypothesize that plafond malreducton and talar body impaction is associated with early posttraumatic arthrosis. Methods: A retrospective cohort of skeletally mature patients with SAD ankle fractures at 2 level 1 academic trauma centers who underwent operative fixation were identified. Patients with a minimum of 1-year follow-up were included. The presence of articular impaction identified on CT scan was recorded and the quality of reduction on final intraoperative radiographs was assessed. The primary outcome was radiographic ankle arthrosis (Kellgren-Lawrence 3 or 4), and postoperative complications were documented. Results: A total of 175 SAD ankle fractures were identified during a 10-year period; 79 patients with 1-year follow-up met inclusion criteria. The majority of injuries resulted from a high-energy mechanism. Articular impaction was present in 73% of injuries, and 23% of all patients had radiographic arthrosis (Kellgren-Lawrence 3 or 4) at final follow-up. Articular malreduction, defined by either a gap or step >2 mm, was significantly associated with development of arthrosis. Early treatment failure, infection, and nonunion was rare in this series. Conclusion: Malreduction of articular impaction in SAD ankle fractures is associated with early posttraumatic arthrosis. Recognition and anatomic restoration with stable fixation of articular impaction appears to mitigate risk of posttraumatic arthrosis. Investigations correlating postoperative and long-term radiographic findings to patient-reported outcomes after operative treatment of SAD ankle fractures are warranted.