Comparison of wear on articular cartilage by titanium alloy, ultra-high-molecular-weight polyethylene, and carbon fibre reinforced polyether-ether-ketone: A pilot study.

Artificial implant materials may articulate against native articular cartilage in certain clinical scenarios and the selection of an implant material that results in the least wear on articular cartilage is preferred to maintain normal joint architecture and function. This project compared the wear on porcine femoral condyles induced by articulation against porcine patellae, titanium alloy (Ti6Al4V), ultra high molecular weight polyethylene (UHMWPE), and carbon fibre reinforced polyether-ether-ketone (CFR-PEEK) through an ex vivo experimental setup. A sinusoidal compressive load of 30-160 N, representing an approximate joint pressure of 0.19-1 MPa at a frequency of 3 Hz coupled with a rotational displacement of +/- 10⁰ at 3 Hz was used to simulate physiological joint motion. Wear was characterized via gross examination and histologically using the OARSI scoring system after 43,200 cycles. CFR-PEEK resulted in the most significant wear on articular cartilage compared to titanium alloy and UHMWPE whereas titanium alloy and UHMWPE resulted in similar levels of wear. All materials caused more wear compared to cartilage-on-cartilage testing. The wear mechanism was characterized by progressive loss of proteoglycan content in cartilage in histology samples.