Long term (>2 years) failure of UHMWPE components in-vivo is predominantly caused by wear of the UHMWPE component. The surface properties of UHMWPE greatly influence the adhesive and abrasive mechanisms of wear that occur in the hip. However, there is not a clear understanding of how in-vivo wear mechanisms influence surface mechanical properties of UHMWPE. In addition, previous researchers have reported wear rates for Charnley UHMWPE acetabular components that vary considerably between patients. It is conceivable that these variations in wear are a result of variations in the surface mechanical properties of UHMWPE. This study used a combination of instrumented indentation testing and Ff-IR imaging to assess the depth dependent micromechanical and chemical properties of 32 retrieved UHMWPE acetabular components. Significant variations in the mechanical and chemical properties of samples taken from worn and unworn regions of retrieved UHMWPE acetabular components were found. In unworn regions, these variations were principally caused by post-irradiation ageing. However, in worn regions, the variation in properties was primarily caused by the wear process.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:508154 |
| Date | January 2009 |
| Creators | Kipping, Michael |
| Publisher | University of Nottingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://eprints.nottingham.ac.uk/14468/ |
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