Impact of the Processing History on the Wear Performance of a PEEK-on-PEEK Bearing for Cervical Total Disc Replacement

摘要

In the present study the wear performance of an all PEEK ball-and-socket concept for cervical total disc replacement (TDR) was assessed by in vitro wear tests. The study focused on the effect of different processing histories - in particular milling versus injection molding - on the wear performance. The bearing surfaces were assessed and the retained wear particles were analyzed for their size and morphology. The obtained wear rates for milled parts and molded parts were found to be similar. Annealing of the molded parts did not alter the wear behaviour significantly. All investgated bearing surfaces showed deterioration with severe signs of wear damage. The study revealed that - independent of the processing history - an all PEEK cervical TDR concept does not seem to offer substantial benefits in terms of wear rates if compared to the well established solutions based on UHMWPE-on-CoCr. Therefore, the use of PEEK as a bearing material for cervical TDR must be critically reviewed.