Long-term compressive property durability of carbon fibre-reinforced polyetheretherketone composite in physiological saline

In total hip arthroplasty, concerns such as corrosion and stress shielding associated with stiff metallic femoral components have led to the development of low stiffness advanced fibre-reinforced polymer (FRP) composite femoral components. Carbon fibre-reinforced polyetheretherketone (CF/PEEK) composite material is now one of the primary material systems being considered for composite hip stem development. As a hip stem, a composite material must be able to support a complex state of stress in the in vivo environment without failure. Considering the loading conditions of a hip stem (superimposed compression and bending), and the fact that FRP composites typically possess lower compressive than tensile strength, the compressive behaviour of FRP composite becomes very important for femoral component design. This paper presents an investigation of the long-term durability of 0 degrees and 90 degrees compressive strengths of CF/PEEK composite following physiological saline saturation. 0 degrees and 90 degrees compressive moduli and Poisson ratio (nu(12)) properties are also reported. Samples were tested following conditioning in physiological saline at 37, 65 and 95 degrees C for time periods from 0 to 5000 h. Dry samples were tested as controls. Results show no significant loss in compressive property values of the saline-saturated or the dry control samples as a function of conditioning time or temperature.