Wear Performance Assessment of Total Ankle Replacement Prostheses: An ISO-Based Comparative Study

Abstract

Abstract. 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 two commercial prostheses, and one anatomical-design implant 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. Specifically, it reduces wear-rates by 27.19% compared to one of the commercial designs, though it exhibits comparable wear performance to the other commercial design. Notably, the latter commercial design itself shows 30.50% lower wear than the former under identical conditions. The wear model applied to the ankle prosthesis has high effectiveness, and the prediction results show that the anatomical-design prosthesis has a more reasonable contact pressure distribution and a lower wear-rate. This validated wear model provides an efficient instrument for the preclinical evaluation of the wear performance of the ankle prostheses and also provides the theoretical basis for the selection of the three ankle prostheses.