Comparison of Dynamic Versus Static Locked Retrograde Tibiotalocalcaneal Arthrodesis With Intramedullary Nail Fixation: Evaluation of the RAIN Database.

Hindfoot osteoarthritis (OA) or deformity involving the ankle and subtalar joint is a disabling condition. Tibiotalocalcaneal (TTC) fusion is an effective salvage option in pathologies where total ankle replacement is contraindicated. The purpose of this study is to compare the union rate of the ankle joint in proximal static versus dynamically locked retrograde intramedullary nail fixation for tibiotalocalcaneal arthrodesis. An institutional review board-approved comprehensive chart and radiographic review was performed. TTC arthrodesis performed in patients with OA, post-traumatic arthritis, or deformity corrected by retrograde nail were included. Patients with Charcot arthropathy, failed joint replacement, neuropathy, or avascular necrosis were excluded. The primary outcome was ankle joint union with secondary measure of mean time to fusion. A total of 60 patients met inclusion criteria with 30 in the static group (SG) and 30 in the dynamic group (DG). The average age of the static group (SG) and dynamic group (DG) was 56.9 and 54.1 years, respectively. Mean body mass index was 34.03 kg/m for SG and 33.43 kg/m for DG. The union rate of the ankle joint was slightly higher in the DG but not statistically significant [SG 83.3%, DG 86.6%, p > .05 (p = .83)]. Time to fusion (TTF) in SG was 111.6 days compared to 97.2 days in DG. Dynamically locked intramedullary nails allow continued compression across the arthrodesis site as fusions remodel. Time to union and union rate of the ankle joint was superior in the dynamic group but this was not statistically significant. In this cohort, union rates were excellent in both groups, and no statistically significant difference was seen in the number of nonunions.