Viewpoint: Yes, the research emphasis on the wear of ultra-high molecular weight polyethylene bearing components in joint replacements is warranted: not only is physical wear the most important factor in the aging and malfunctioning of joint replacements, but it is closely tied with chemical and biological factors.

Viewpoint: No, the current research emphasis on the wear of polyethylene bearing components in joint replacements is unwarranted, given that alternative materials are available that can provide not only greater longevity but biological tolerance as well.

Prosthesis is the development of...