Computational Wear Prediction of UHMWPE in Knee Replacements

A multibody dynamic contact model predicted the damage sustained by two tibial inserts tested under different conditions on an AMTI knee simulator machine. The model required a wear factor of 7.7×10^-7 mm³/Nm to match the wear volume measured from the first insert after 0.86 million cycles of simulated gait. The model matched the medial and lateral damage depths measured from the second insert to within 0.3 mm after 5 million cycles of simulated gait and stair (10:1 ratio). Computational models may be valuable for screening new knee implant designs rapidly and performing sensitivity studies of component positioning issues.