Many endoprosthetic joint replacements currently implanted in patients include a highly polished metal or ceramic component articulating on an ultra high molecular weight polyethylene (UHMWPE) material.  Wear and abrasion resistance, coefficient of friction, impact strength, toughness, density, biocompatibility and biostability are some of the properties that make UHMWPE a suitable material for such implants.  Although UHMWPE has been used in implants for many years, there is continuing interest in the wear and durability characteristics of implants incorporating UHMWPE.