Publications

Abstract

Although there are several material combinations available for use in orthopaedic devices (such as metal-on-polymer, metal-on-metal and ceramic-onceramic) a number of ‘new’ materials such as
polyetheretherketone (PEEK-OPTIMA), carbon fibre reinforced PEEK-OPTIMA (CFR-PEEK) and an alternative nonreinforced high molecular weight polyetherketone (PEK) may provide viable alternatives in some applications. All polymeric wear couples have had limited investigation for use in orthopaedic implants but may provide engineers with new approaches for the design of medical devices such as in spinal arthroplasty. Four station pin-on-plate wear machines were used. Multi-directional motion included reciprocation and rotation (1 Hz). 40 N load was applied in 25% bovine serum (protein content 15 gl-1) at 37°C. Specimens were tested to 2-5 million cycles. Standard PEEK-OPTIMA against itself gave the highest wear. Although PEK/PEK gave lower wear factors than PEEKOPTIMA/PEEK-OPTIMA, CFR-PEEK-OPTIMA (both Pitch and PAN-based) gave even lower wear. Both the CFR-PEEK-OPTIMA articulating against CFR-PEEK-OPTIMA and the PEK bearing against PEK provided lower wear than standard PEEK-OPTIMA/PEEK-OPTIMA samples. Standard PEEK-OPTIMA against itself is currently used
in a disc arthroplasty system which is undergoing clinical trials. These material combinations may perform well in other applications such as prosthetic joints.