Mechanical Interaction between Vitamin E-Containing Ultrahigh Molecular Weight Polyethylene and Co-28Cr-6Mo Alloy in Water

Abstract

The mechanical interaction between ultrahigh molecular weight polyethylene (UHMWPE) and a Co-28Cr-6Mo alloy in water was examined in order to clarify the wear resistance mechanism of vitamin E-containing UHMWPE in knee prostheses. The sample UHMWPE was pressed and rubbed against the surface of the Co-28Cr-6Mo alloy in water by using a computer-controlled pin-on-disk wear test apparatus. The formation of a UHMWPE transfer film on the surface of the Co-28Cr-6Mo alloy was reduced by the addition of vitamin E to UHMWPE. The pull-away force between UHMWPE and the Co-28Cr-6Mo alloy was also reduced by the addition of vitamin E. These results suggest that vitamin E reduces the attraction between UHMWPE and the surface of the Co-28Cr-6Mo alloy.