easuring the wear of a new, all-polymer PEEK-OPTIMA femoral knee component for total knee replacement

One in 5 total knee replacement patients receiving a conventional metal-on-polyethylene implant report dissatisfaction with their prosthesis. One potential reason for this dissatisfaction relates to the materials from which the joint is manufactured. The cobalt chrome femoral component is heavy, has a high modulus, low thermal conductivity and the potential to release metal ions. To address these issues, Invibio Limited have developed a novel all polymer knee replacement solution, comprising PEEK-OPTIMA femoral component coupled with an all-polyethylene tibial component. The advancement of such musculoskeletal interventions such as joint replacements is essential to the ageing population and aims to provide better quality of life, bring high standard affordable healthcare to a larger market whilst tackling national and global healthcare issues.

Prior to clinical adoption of new medical devices, the functional performance under a wide envelope of clinically relevant conditions replicating those the knee will be subjected to in the body should be investigated. In particular, understanding the tribology of the knee replacement is important to predict its longevity in vivo. In this material combination, it can no longer be assumed that wear will be constrained to the UHMWPE tibial insert, and it will be critical to understand whether wear of the femoral PEEK component will occur. Currently, methods to assess the wear of the femoral component are limited, and compounded by material considerations in this case such as moisture uptake by the PEEK material. The focus of this PhD research will therefore be the development and validation of new measurement methods to determine the wear of the PEEK femoral component.