Wear of Ti-6A1-4V Implant Alloy and Ultrahigh Molecular Weight Polyethylene Combinations

Abstract

In view of published comments that the wear resistance of Ti-6Al-4V alloy bearing against ultrahigh molecular weight polyethylene (UHMWPE) was not adequate for total joint replacements, the literature was reviewed and compared with ongoing hip simulator studies. Two types of laboratory tests were contrasted: those run under “clean” conditions and those run with intentional contamination by acrylic cement particles. Wear-screening devices as well as hip simulators were involved in both types of studies, and both produced a dichotomy of viewpoints on the suitability of the Ti-6Al-4V/UHMWPE combination. However, the two most recent studies with hip simulators indicated that the Ti-6Al-4V-UHMWPE combination performed acceptably well. The published data from a major series of Ti-6Al-4V hip replacements have established excellent clinical and radiographic results. In seven surgical revisitations, the Ti-6Al-4V/UHMWPE combinations showed no sign of adverse wear phenomena. Thus, the clinical observations are supportive of the results of the two most recent hip simulator studies. It may well be that the laboratory models produced a variety of severe test conditions that compromised the performance of the Ti-6Al-4V and resulted in contradictory data. The hip simulator studies are being continued to establish the limits of the laboratory models and their validity with respect to the clinical situation.

Wear of the polyethylene acetabular cup: Metallic and ceramic heads compared in a hip simulator

“…The literature contains contradictory viewpoints on the suitability of the material (Clarke et al 1983, Nasser et al 1990, Davidson 1992). In our simulator the performance of ion-implanted sample Biomet heads was, perhaps somewhat surprisingly, quite satisfactory considering the very low wear rate of the cups, despite the considerable roughening of the titanium articular surfaces during the tests.…”

Nanoscale characterization of anodic oxide films on Ti-6Al-4V alloy

“…Ti-6Al-4V is widely used for biomedical applications, as the introduction of alloying elements enhances the mechanical properties. This is in spite of the fact that Ti-6Al-4V seems to exhibit a poor wear resistance [3][4][5], which can cause significant release of Al and V. The release of Al and V from the implant into body is most undesirable due to the element's toxic effects [6].…”

Osseointegration of Ti6Al4V alloy implants coated with titanium nitride by a new method

“…Experimental tests have shown the influence of the stiffness of the stem on cement stress 21,22 and numerical studies have indicated that stiffer stems induce higher distal stress [23][24][25] and unload the proximal femoral bone, leading to stress shielding. 22,26 Conversely, in vitro 27 and in vivo, 28 studies have concluded that stems with lower stiffness are susceptible to wear, which may lead to the generation of particulate metallic debris. [28][29][30] The influence of material stiffness on long-term behaviour remains unclear.…”