Poly-ether-ether-ketone (PEEK) is a high performance aromatic thermoplastic with proven biocompatibility. Recently, it has been proposed as a promising bearing material for cervical total disc replacement (TDR). A new bearing combination of PEEK-on-PEEK based self-mating articulation has been used, which may overcome current bearing materials related complications. For ball-on-socket based cervical TDR designs, PEEK based bearing articulation is expected to operate under a boundary lubrication regime regardless of the radial clearance used. The contact stress encountered by the bearing surfaces is insufficient to result in either material yield or fatigue failure. High-cycle fatigue tests were performed on PEEK 450G specimens via three-point flexural bending. The obtained fatigue results (104.1 ± 5.8 MPa) show superiority over the historical polymeric bearing material UHMWPE (31 MPa). Moreover, it demonstrates a good resistance to sterilisation and thermal ageing. Laboratory wear simulation was also conducted, using spine simulators and following ISO 18192-1 standard. For PEEK-on-PEEK self-mating articulation, a steady state wear rate of 1.0 ± 0.9 mg/million cycles is obtained, which is comparable as the historical bearing combination (UHMWPE against CoCrMo). The results of this work suggest that PEEK-on-PEEK based articulation is a possible alternative for future cervical TDR designs.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:600250 |
| Date | January 2014 |
| Creators | Xin, Hua |
| Publisher | University of Birmingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://etheses.bham.ac.uk//id/eprint/4378/ |
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