Long-term Survivorship of Transfibular Trabecular Metal Total Ankle Arthroplasty: 10-Year Minimum Clinical and Radiographic Follow-up

BACKGROUND: Total ankle arthroplasty (TAA) utilization has rapidly increased over the last decade despite relatively unknown long-term survivorship of fourth-generation implants. The purpose of this study was to determine the long-term survivorship of the trabecular metal (TM) transfibular TAA and report relevant interval changes. METHODS: Retrospective review was performed of prospectively followed patients who underwent primary transfibular TAA by a single surgeon from October 2012 to February 2016, including patients with minimum 10-year clinical and radiographic follow-up. Patient-reported outcomes measures (PROMs) included 12-item Short Form Health Survey physical (SF-12 PCS) and mental (SF-12 MCS) component summary scores, Ankle Osteoarthritis Scale (AOS), and visual analog scale (VAS). Radiographic outcomes included alignment, motion, presence of periprosthetic lucencies. Adverse events and reoperations were reported using the Canadian Orthopaedic Foot and Ankle Society (COFAS) Reoperation Coding System (CROCS). RESULTS: Seventy-one ankles (68 patients) were included out of 79 TAAs (89.9%) with mean age of 61 (range, 28-80) years. Mean follow-up was 11.0 years (IQR, 1.5). There was 1 metal component revision (MCR) for periprosthetic joint infection requiring below-knee amputation (CROCS 11). Twenty-nine (40.8%) ankles underwent reoperations, with no ankles requiring more than 3 reoperations. The most common indication for reoperation was gutter debridement (n = 12; CROCS 4). Five cysts were detected in 4 ankles (7%) at final follow-up. Postoperative PROMs, radiographic alignment and motion were stable between 5- and ≥10-year time points. CONCLUSION: This single surgeon cohort demonstrated 98.6% implant survivorship of the TM transfibular TAA at a mean 11-year follow-up. Radiographic evaluation showed stable alignment and range of motion between midterm and long-term follow-up, and low rates of periprosthetic lucencies with minimal interval osteolysis between 5- and 10-year evaluations. Overall, these results support transfibular TAA as a durable long-term treatment for ankle arthritis. LEVEL OF EVIDENCE: Level IV, case series.