Tribological evaluation of oxidized zirconium using an articular cartilage counterface: a novel material for potential use in hemiarthroplasty.

Problems with total joint replacement that have surfaced in recent years have made reconsideration of more conservative hip reconstructive procedures compelling. Moreover, procedures such as hemiarthroplasty might benefit from newly developed materials that could provide more favourable tribological performance when employed as a counterface for articulation with articular cartilage. The objective of this study was to evaluate the tribology of a new biomaterial, oxidized zirconium, with articular cartilage in a laboratory test apparatus. Oxidized zirconium components are produced by oxidizing the zirconium alloy to form a relatively thick (7 microns), adherent, abrasion-resistant ceramic surface. We found that the coefficient of friction of bovine articular cartilage rubbed against oxidized zirconium was lower than with cobalt-chromium alloy control surfaces, and that there was a trend toward less wear with oxidized zirconium. A defined layer of degraded tissue was found on the surface of the articular cartilage specimens, providing some indication of the mechanism of wear. Results of this study warrant further investigation of oxidized zirconium as the bearing surface for hemiarthroplasty.