POLYETHYLENE IN TOTAL JOINT ARTHROPLASTY - A DEAD-END FOR PERMANENT IMPLANTS

Faced with a growing number of younger patients in need of total joint arthroplasty, orthopaedic surgeons are demanding long-term implants f or total joint replacement. An assessment of the long-term mechanical behaviour in vivo of all biomaterials in common use in prostheses is i n progress. In the present paper, we discuss the long-term reliability of polyethylene (UHMWPE) in joint replacement in terms of tribology a nd the different biomechanical situation in various human joints. Long -term failure mechanisms for polyethylene in total hip arthoplasty (TH A) differ from those seen in total knee arthroplasty (TKA) although th e same materials are used. It is thus questionable whether improvement s in wear rates of polyethylene in THA would be helpful in TKA.