Wear Prediction for Zr-Nb-on-Zr-Nb Hip Prostheses under Real Gait Conditions

Wear remains a significant challenge in total hip arthroplasty (THA) for treating advanced degenerative hip diseases. To investigate the wear behaviour of hip prostheses under real gait conditions, this study proposes a wear prediction scheme for Zr-Nb-on-Zr-Nb hip prostheses. The aim is to evaluate their wear performance under physiological loading gait cycle and optimise the radial clearance design. The scheme calculates the proportional relationship of the wear coefficient between Zr-Nb alloy and CoCrMo alloy using pin-on-disk wear tests and finite element analysis (FEA), thereby accurately quantifying the wear coefficient of Zr-Nb-on-Zr-Nb hip prostheses. Integrating the Archard wear model with dynamic contact mechanics enables the wear of hip prostheses to be predicted. Results show that Zr-Nb-on-Zr-Nb hip prostheses wear coefficients during the running-in and steady-state phases are 8.7826 × 10-10 and 2.6348×10-10 mm3N-1m-1. Compared with CoCrMo-on-CoCrMo hip prostheses, the linear and volumetric wear rates are reduced by 82.73% and 82.12%, and peak contact pressure decreases by 39.09%. Radial clearance analysis shows that increasing radial clearance leads to higher peak contact pressure and volumetric wear. This study demonstrates that Zr-Nb-on-Zr-Nb hip prostheses exhibit excellent wear resistance and biomechanical properties, providing a solid theoretical basis for prostheses design and lifespan prediction.