Wear performance assessment of total ankle replacement prostheses: An ISO-based comparative study

Despite advancements in wear models for joint implants, comprehensive prediction of ankle implant wear remains challenging, and quantifying implant wear properties, crucial for preclinical evaluations, remains understudied. This study aims to develop a comprehensive ankle implant wear model based on ISO 22622, and subsequently evaluate ankle implant wear properties of the commercial prostheses and anatomical-design prosthesis. A cross-shear contact-pressure dependent wear model for ankle implants based on ISO 22622 is established and validated, and the contact stress, contact area and wear properties of INBONE II, INFINITY, and anatomical-design implants were quantified. The developed wear model has been validated to be able to predict the wear characteristics of ankle prostheses. The anatomical-design prosthesis demonstrates superior contact stress distribution versus commercial designs (INBONE II/INFINITY). Specifically, it reduces wear rates by 27.19% compared to INBONE II, though exhibits comparable wear performance to INFINITY. Notably, INFINITY itself shows 30.50% lower wear than INBONE II under identical conditions. The wear model applied on ankle prosthesis has high effectiveness, and the prediction results show that the anatomical-design prosthesis has more reasonable contact pressure distribution and lower wear rate. This validated wear model provides the efficient instrument to the preclinical evaluation of the wear performance of the ankle prostheses, and also provides the theoretical basis of the select of the three ankle prostheses.