The wear of metal-on-metal total hip prostheses measured in a hip simulator.
New generation metal-on-metal prostheses have been introduced to try and overcome the problem of osteolysis often attributed to the wear particles of the polyethylene component of conventional metal-on-ultra-high molecular weight polyethylene (UHMWPE) joints. The wear rates of four metal-on-metal joints (two different clearances) were assessed along with that of a conventional metal-on-UHMWPE joint. Friction measurements of the metal-on-metal joints were taken before and after the wear test and compared. Two distinct wear phases were discernible for all the metal-on-metal joints: an initial wear phase up to 0.5 x 10(6) cycles and then a lower steady state wear phase. The steady state wear rate of the 22 microm radial clearance metal-on-metal joint was lower than that for the 40 microm radial clearance joint, although this difference was not found to be significant (p > 0.15). The wear rates for all the joints tested were consistent with other simulator studies. The friction factors produced by each joint were found to decrease significantly after wear testing (p < 0.05).
Scholes
S C
SC
Centre for Biomedical Engineering, School of Engineering, University of Durham, UK.
Green
S M
SM
Unsworth
A
A
D001672:Biocompatible Materials; D019544:Equipment Failure Analysis; D017276:Friction; D006622:Hip Prosthesis; D006801:Humans; D008153:Lubrication; D008422:Materials Testing; D008670:Metals; D010014:Osteolysis / Q000209:etiology / Q000517:prevention & control; D011095:Polyethylenes; D011475:Prosthesis Failure; D013314:Stress, Mechanical; D006113:United Kingdom; D014800:Vitallium
D001672:Biocompatible Materials; D008670:Metals; D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene; D014800:Vitallium