REVISION RATES OF NEW TOTAL ANKLE ARTHROPLASTY VERSUS OLD TOTAL ANKLE ARTHROPLASTY: A COMPREHENSIVE COHORT STUDY

In recent years, total ankle prosthesis (TAR) implants have improved, as demonstrated by various studies. Additionally, there has been an exponential increase in the number of patients undergoing this surgery. While there are national registries that have compared different types of total ankle prostheses, there is limited literature where the same group of surgeons compares their results of previously implanted prostheses with those achieved using newer prostheses, thereby enhancing the internal validity of the conducted analysis. This is a retrospective cohort study of all total ankle prostheses implanted in a single tertiary center by five specialized foot and ankle surgeons. All total ankle prostheses performed between 2003 and 2023 were analyzed, excluding revision prostheses and patients who declined to be part of the registry. The follow-up for each prosthesis began at the time of the initial surgery, with prosthesis revision considered a treatment failure. Revision was defined as the replacement of a metallic component, amputation, or arthrodesis. The Agility, Hintegra, STAR, and Mobility prostheses were grouped as ‘old prostheses,’ while the Infinity, InBone II, and Zimmer Biomet prostheses were considered ‘new prostheses.’ Patient age at the time of surgery, histories of diabetes, and the different etiologies of ankle osteoarthritis were compared between the two groups. A Kaplan-Meier curve was generated to determine differences in revision rates between the groups. A total of 447 total ankle replacements were included in the study, which showed that there were no statistically significant differences between the two groups regarding diabetes (p = 0.15). However, there were differences in the age at the time of surgery, with it being higher in the new prostheses group (p The average follow-up period for the old prostheses was 12.5 years [0.01 - 21.75], while for the new prostheses, it was 5.8 years [0.14 - 15.25]. This difference was statistically significant (p The Kaplan-Meier curve showed a 15-year revision rate of 11.4% (CI: 0.078 - 0.166) for new prostheses and 30.7% (CI: 0.251 - 0.372) or old prostheses over the same period (fig. 1). Up to 15 years of follow-up, our cohort found that newer TAR designs provide greater survivorship compared to previous TAR designs. For any figures or tables, please contact the authors directly.