Understanding the biomechanics and wear of a novel modular tray for an all-polymer total knee replacement

25% of patients who receive a conventional metal-on-polyethylene Total Knee Replacement report problems during the first year after their operation, and rising demand for improved performance coming from younger more active patients presents a major challenge. A novel all-polymer knee replacement, comprising PEEK-OPTIMA-on-polyethylene, has been developed by Invibio Limited to address these challenges.

It is expected products such as this will deliver the innovation needed to treat musculoskeletal diseases, provide better quality of life, ensure higher standards of affordable healthcare, and drive economic growth by bringing new orthopaedic products to market that help tackle national and global health challenges.

To date, the all-polymer knee replacement has used an all-polyethylene tibial component. However, clinical preference is for a modular design, where a polyethylene insert would clip into a PEEK tray. The implications of a modular PEEK tibial tray in terms of joint biomechanics and wear are unknown, and the aim of this research is to explore the biomechanical and tribological implications at the articulating surface and interface of the tibial tray.

The project is based in the Institute of Medical and Biological Engineering (www.imbe.leeds.ac.uk), a leading global centre of excellence in medical and biological engineering.

This research project is directly aligned with the EPSRC health technologies strategy, detailed within the EPSRC strategic delivery plan 2022 to 2025. Transforming health and healthcare is one of the four mission-inspired research priorities of the EPSRC, with EPSRC committing to transforming healthcare through leading the design and development of future and affordable healthcare technologies.

The fit of our strategic collaboration with Invibio to develop affordable medical technology has already been recognised by EPSRC with the recent award of a Prosperity Partnership. This project is also aligned with the Government's UK Innovation Strategy, which recognises that to become an international leader in innovation we must create products and services that are successful in international markets, and which provide solutions to the great challenges (for example ageing society) the world faces.

Also detailed in the Strategy are seven technology families of UK strength and opportunity, one of which is advanced materials and manufacturing. This research project will deliver fundamental methods, understanding and implications of advanced materials in a unique tribological configuration.

The strategy of the Institute of Medical & Biological Engineering is to engineer 50 active years after 50 through multi-disciplinary research, innovation, knowledge creation and translation. One of the strategic research themes is to develop systems for research, design, development and pre-clinical evaluation of joint replacements. This proposed PhD project fits within this specific theme.

Our Institute has the largest academic facility in the world for experimental simulation of joint replacements, in which the School and EPSRC have strategically invested, and this project will use a new electro-mechanical knee simulator (expected delivery July 2024). This project is aligned with the University 2020-30 strategy of performing high-quality, challenge-led, interdisciplinary research, underpinned by our fundamental research strengths.

The student will use capability and infrastructure within the Institute of Medical and Biological Engineering built up over >25-years, including state of the art simulators for analysing wear of total joint replacements. In addition, facilities within the Faculty of Engineering and Physical Sciences will be used including those in the Bragg Centre for Materials Research such as the electron microscopes in LEMAS for high magnification analysis of the surfaces.