15-YEAR SURVIVORSHIP OF PRIMARY TOTAL ANKLE ARTHROPLASTY: A NATIONAL REGISTRY STUDY

Total Ankle Arthroplasty (TAA) is a definitive treatment for end-stage ankle arthritis. Its use has become increasingly popular, however, there is limited long-term evidence on implant survivorship. The aims of this study were to determine fifteen-year survivorship of primary TAA in Scotland, compare different implants, and assess patient characteristics associated with failure. This study comprised multicentre data from the Scottish Arthroplasty Project between 2000 and 2023, linked with national morbidity and mortality national records. Survivorship was defined as retention of all primary components without removal, exchange, or conversion to arthrodesis. Life tables and Kaplan-Meier survival curves were generated, and Cox proportional hazards regression models were fitted to identify independent associations with failure. There were 1,262 primary TAAs. Overall survivorship was 98.9% (95% CI 98.4–99.5) at one year, 96.5% at five years (95% CI 95.3–97.6), 90.9% at ten years (95% CI 88.5–93.4), and 81.9% at fifteen years (95% 77.5-86.5). Survivorship differed significantly between implant designs, with Mobility demonstrating higher failure rates (19%) compared with Infinity (7%) and STAR (7%). Median length of stay decreased over the study period (2 days, (IQR 1-4). There were no differences in outcomes by age, sex, or socioeconomic deprivation. Total ankle arthroplasty in Scotland demonstrates good long-term survivorship, with over 80% of implants surviving at fifteen years. Implant design was the principal determinant of failure, underscoring the importance of ongoing evaluation of implant performance in national registries.