The total knee replacement systems (TKRS) are used for the treatment of osteoarthritis and rheumatoid arthritis. Excessive wear can substantially shorten their life span.

Two tests were performed to examine the wear characteristics of tibial bearings used in TKRS. Each test consisted of six sets of Anterior/Posterior Glide Tibial Bearings each with a conical control arm. The tibial bearings were all made by UHMWPE. Three of these bearings were mounted onto a Co-Cr alloy tibial platform and Co-Cr alloy LCS® femoral component. Another three sets of bearings were mounted onto a TiN tibial platform and TiN LCS® femoral component. They were put into New Jersey Mark III Knee Simulator System. The simulator was configured to produce flexion-extension and axial rotation to simulate the normal walking gait. The tests were run at L6 Hz. Distilled water was used as lubrication fluid.

The test results show that the loading conditions and femoral component geometry play very critical roles. However, due to the machine problems, contamination of cooling-lubricating system, other factors related to loading conditions and femoral component geometry, the wear characteristics of the tested systems cannot be determined. In light of this test, the New Jersey Mark III Knee Simulator mechanical design and control systems need to be reviewed and corrected.