Tribocorrosion at the taper junctions of femoral components in total hip arthroplasty is a complex mechanism and a source of metal release in the body. Understanding the various modes and mechanisms of in-vivo corrosion and the pathogenesis of the body’s biological response that results in implant failure is of significant clinical importance. This thesis focused on the forensic analysis, using both metrology methods and synchrotron radiation, of a class of modular orthopaedic implants - dual-taper hip arthroplasty, retrieved from patients whose hip replacements were revised secondary to adverse reaction to metal debris (ARMD). Emphasis was placed on the forensic investigation of the neck/stem junction of contemporary designs and the recalled Rejuvenate modular femoral stem. All the retrieved implants in the CoCr/Ti combination group showed moderate to severe corrosive attack. The severity of taper degradation was found to increase with implant time in situ and to be associated with a greater Co to Cr ion ratio in the blood. Metal species identified in periprosthetic tissue from these corroded implants, were analysed for metal distribution and oxidation state by means of synchrotron radiation. For the first time, Ti was found in an amorphous dioxide form and Cr in Cr2O3. The metal species showed preferential affinity between each other and were often co-localized. This suggests that the complexity (in morphology and chemistry) of the debris may play an active role in eliciting a pathologic response in periprosthetic tissues. The findings from this body of research will inform future toxicological studies and may provide useful information helping to better design future pre-marketing tests of orthopaedic implants and more broadly the understanding of the metal/metal and metal/body interactions.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:747474 |
| Date | January 2018 |
| Creators | Di Laura, Anna |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/10045267/ |
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