A tribological assessment of a PEEK based self-mating total cervical disc replacement

This paper presents an in-vitro tribological investigation of the PEEK (Poly-ether-ether-ketone) based self-mating articulation of the NuNec cervical disc replacement. All tests were undertaken using Bose spine simulator. Discs were subjected to wear tests and this involved applying the load and motions given in ISO 18192-1. Wear was determined from the mass loss from the specimens. Testing continued until 5 million cycles had been completed. Disc were subjected to friction tests, before and after the wear testing; each specimen was tested under a constant axial compressive and then subjected to the motions given in ISO 18192-1. Stribeck analysis was used to determine the lubrication regime. The wear rates for the initial phase (0-2 million cycles) and the steady stage (2-5 million cycles) were 4.8±1.5mg/million cycles and 1.0±0.9mg/million cycles, respectively. Over the entire test period, the total mass loss was 12.5±0.4mg. The Stribeck analysis showed that this cervical disc will operate under boundary or mixed lubrication.