A multi‐directional wear screening device and preliminary results of UHMWPE articulating against stainless steel

Abstract

This paper describes the design of a pin on plate rig which has been modified to give multi‐directional motion to the test pins, resulting in elliptical and quasi‐elliptical wear paths. Such paths are closer to those seen in vivo by a femoral head articulating against an acetabular cup. The description of the rig is augmented by the results of a test of ultra high molecular weight polyethylene pins rubbing against stainless steel plates, with dilute bovine serum at 37^○C being used as the lubricant. With standard reciprocating motion, a mean wear factor of 0.085 × 10⁻⁶ mm³/N m was found, but with multi‐directional motion, the mean wear factor increased to 1.10 × 10⁻⁶ mm³/N m, which is very similar to in vivo wear factors.