TRIBOLOGICAL INVESTIGATIONS OF THE WEAR COUPLE ALUMINA-CFRP FOR TOTALHIP-REPLACEMENT

Wear debris is the main reason for aseptic loosening in total hip. Mos t troublesome is the wear of polyethylene cups. Ceramic femoral heads were introduced about 20 years ago. The combination ceramic-on-polyeth ylene reduces the wear rate and the loosening rate. But cups of polyet hylene are still the weakest link in a hip prosthesis. Carbon fibre re inforced plastic (CFRP) was proposed as an alternative for polyethylen e. Various test were performed to study the combination metal-on-CFRP, zirconia-on-CFRP, and alumina-an-CFRP. The simulator tests showed tha t the wear rate of alumina-on-CFRP is in the order of 1-3 mu m per yea r. Based on investigation of retrieved implants the wear rate is 6.3 m u m per year. Based on these results the combination alumina femoral h eads (Biolox(R)-forte) and CFRP cups (Caproman(R)) could be approved f or total hip replacement. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.