Tribological testing of articular cartilage of the medial compartment of the knee using a friction simulator

The aim of this study was to develop a tribological simulation of a unicondylar natural knee, to measure the friction and wear of articular cartilage (AC) against itself (AC-vs-AC) and against stainless steel (SS) simulating a hemiarthroplasty (AC-vs-SS). AC-vs-AC produced low levels of friction and no wear was found. AC-vs-SS showed higher levels of friction and significant AC wear. Using AC-vs-SS with elevated loading, the wear of AC was accelerated and through to bone. This study demonstrated the importance of contact stress in the design of a spacer hemiarthroplasty for the medial compartmental knee. Initial results showed the importance of contact mechanics, stress and biomaterial type in determining short-term tribological function and long-term clinical outcome of hemiarthroplasty.