Quantification of third-body damage and its effect on UHMWPE wear with different types of femoral head

We examined stainless-steel, cobalt-chrome, titanium and alumina and zircon ia ceramic femoral heads retrieved at revision surgery. All the heads had a rticulated against ultra-high-molecular-weight-polyethylene (UHMWPE) acetab ular cups. We studied the simulation of third-body damage and the wear of U HMWPE against the various materials used for the heads. The surfaces of the retrieved heads were analysed using a two-dimensional contacting profilome ter. Third-body damage was characterised by the mean height of the scratche s above the mean line (R-pm). The alumina ceramic and zirconia ceramic retrieved heads were found to have significantly less damage. In laboratory studies the ceramics were also mo re resistant to simulated third-body damage than the metal alloys. We studi ed the wear of UHMWPE against the damaged counterfaces in simple configurat ion tests. The damaged ceramics produced less polyethylene wear than the da maged metal counterfaces. The wear factor of UHMWPE against the damaged mat erials was dependent on the amount of damage to the counterface (R-p). Our study has shown the benefit of using the harder and more damage-resistant c eramic materials for femoral heads.