Implant failure after ankle arthrodesis versus total ankle arthroplasty: a matched- cohort study

Objective: To compare the risk of implant failure between ankle arthrodesis and total ankle arthroplasty using propensity score matching and time-to-event analysis. Methods: This multicenter retrospective cohort study used data from the TriNetX Global Collaborative Network. Adult patients aged 18-100 years with ankle osteoarthritis who underwent ankle arthrodesis or total ankle arthroplasty between 2012 and 2023 were included. Propensity score matching (1:1) was performed to balance demographic and clinical covariates. Implant failure was the primary outcome. Survival analyses were conducted using Kaplan-Meier methods and Cox proportional hazards regression, with follow-up censored at implant failure, death, loss to follow-up, or three years after the index date. Results: Among 7,973 eligible patients, 2,745 matched pairs were analyzed. Implant failure was more frequent after ankle arthrodesis than after total ankle arthroplasty (17.4% vs 12.0%; p < 0.001). Arthrodesis was associated with a higher hazard of implant failure (HR 1.94; 95% CI, 1.75-2.15). Elevated hemoglobin A1c independently increased the risk of failure, whereas body mass index and serum albumin did not. Conclusion: Ankle arthrodesis was associated with a significantly higher risk of implant failure compared with total ankle arthroplasty. Metabolic optimization, particularly glycemic control, should be considered in surgical decision-making. Level evidence III; Retrospective Comparative Study