Title: Tribological characteristics of polyethylene bearings of knee prostheses

Authors: Francis E. Kennedy, Douglas W. Van Citters, John P. Collier

Addresses: Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA. ' Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA. ' Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA

Abstract: This paper deals with the problem of tribological failure of artificial knee prostheses. The clinical problem is introduced by analysis of worn knee bearings made of ultra-high molecular weight polyethylene. Three different failure mechanisms are described: subsurface-originated contact fatigue failure, surface-originated wear of the articulating surface, and surface-originated wear of the back (non-articulating) surface. The wear processes were simulated in a rolling/sliding wear tester built for this specific purpose. The influence of gamma-irradiation dose on wear and contact fatigue was determined. Wear was greatest at the portion of the wear track where the lubricating fluid film was thinnest and a boundary or mixed lubrication regime prevailed.

Keywords: knee prostheses; UHMWPE; ultra-high molecular weight polyethylene; rolling wear; sliding wear; lubrication; tribology; tribological failure; artificial knees; contact fatigue; gamma irradiation; radiation dose; polyethylene bearings; total knee arthroplasty; TKA.

DOI: 10.1504/IJSURFSE.2010.030487

International Journal of Surface Science and Engineering, 2010 Vol.4 No.2, pp.166 - 174

Published online: 18 Dec 2009 *

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