Influence of Loading Modes and Parameters on Wear Testing of Unicompartmental Knee Prosthesis

Loading modes and parameters on wear testing of unicompartmental knee prostheses are important. The difference in wear assessments of unicompartmental knee prosthesis under total knee loading mode and unicompartmental loading mode was investigated via computational simulation. The ISO standard testing protocol and the measured personalised load and kinematic data were further used to reveal the influence of the testing parameters on wear assessments. Compared with the total knee loading mode, the unicompartmental loading mode produced a larger peak contact pressure of the tibial insert throughout the wear cycle. Under ISO 14243-3 and Stan’s CAMS testing parameters, the predicted volumetric wear of tibial inserts of the unicompartmental loading mode increased by 28.21% and 15.18%, respectively, compared with the total loading mode. Compared with ISO 14243-3, volumetric wear increased by 42.64% for total knee loading mode and 28.14% for unicompartmental loading mode under Stan’s CAMS loading conditions. Both loading mode and parameters played an important role in the wear of unicompartmental knee arthroplasty simulation. Therefore, wear testing and computational simulation of wear predictions for unicompartmental knee prostheses should be performed in a unicompartmental loading mode, and it is more reasonable to use the patient’s in vivo measurement data.