Comparison of the Wear Performance of the New Vitamin-E Doped Insert under Standard Gait and Stair Climbing

To study the friction and wear of artificial knee joint prosthesis under ISO standard gait and stair climbing. Based on the research and analysis of daily activity frequency, dynamics and kinematics, using artificial knee joint wear test machine, a new Vitamin E type artificial knee joint was underwent 5 000 000 standard gait wear test and 2 000 000 stair climbing wear test. The wear rate in the normal gait phase was 4.34 mg/mc and the wear rate in the stair climbing phase was 5.95 mg/mc. Compared with the standard gait, the movement of the stair climbing has a greater impact on the wear of the insert. The surface morphology of the insert has also changed significantly compared with the standard gait after wearing, and a striped pattern appears and pitting, this surface morphology result is closer to the surface of clinical insert extractions. At present, the standard wear test method for artificial knee joint prostheses is not comprehensive enough, and it needs to be improved to reflect the significance of in vitro wear testing better.