Enabling Individualised Surgical Treatment of Osteoarthritis

Osteoarthritis affects over eight million people in the UK alone, with nearly three quarters of patients reporting some form of constant pain. Treatment for arthritis is estimated to cost the UK healthcare system over £10 billion per year, with significant additional societal costs for lost working hours and welfare payments. Although hip and knee replacement surgeries are considered successful, these treatments are not suitable for all patients and some devices fail early, requiring costly and less successful revision surgery. There are over 15,000 revision surgeries performed in the UK alone each year. Younger and more active patients, as well as rising numbers with obesity, are placing greater demands on these treatments: implants need to last for longer and withstand more extreme loading than ever before. There is evidence that both individual patient biomechanics and surgical choices influence the outcomes of these treatments. Improved outcomes, particularly for more challenging patient groups, can only be achieved by better matching the treatment to the functional requirements of the individual patient. This proposal will bring together complementary research expertise from two of the world's leading research institutes in the field to build the evidence needed to enable treatments for osteoarthritis to be better tailored to individual patient needs. The Institute of Medical and Biological Engineering at the University of Leeds has developed unique capability and expertise to evaluate artificial and natural joints. These include the world's largest academic facility for experimentally testing joint replacements, as well as computational modelling methods to simulate how implants perform in the body. These capabilities enable the mechanical performance of implants to be evaluated under a range of different conditions, for example to study how the implant wears over time or becomes damaged with usage. The Center for Orthopaedic Biomechanics at the University of Denver has developed world-leading capability in measuring patient joint mechanics in vivo, including methods of imaging patient joints as they undertake different activities, and parallel computational methods for deriving biomechanical information. These methods enable the forces and motions on an individual patient's hip or knee joints to be derived and, by collecting data on many patients, examine how these differ from one individual to another. By combining the expertise across both groups, this Centre-to-Centre Research Collaboration will enable relationships to be developed between an individual patient's characteristics (e.g. their anatomy and how they load their joints) and the mechanical performance of the implant. Specifically, in the hip we will combine methodologies developed at the two centres to evaluate how patient and surgical factors affect the risk of early failure in hip replacements due to the device components pushing into each other or the surrounding bone (impingement), or the way the components are aligned. We will also examine how different choices of implant can influence the outcomes. In the knee, we will combine methodologies to identify how patient factors (such as the anatomy of the knee and the way it is loaded during different activities) affect early-stage treatments for knee osteoarthritis. We will also examine the effects of a greater range of activities, such as squatting and stair climbing, on the outcomes of knee replacements. These studies will bring together different methodologies and build new pathways for acquiring and sharing data that can be adopted more widely and applied to other musculoskeletal systems in the future. The work will build the evidence needed to improve hip and knee implant design, inform clinical decision-making, enhance patient quality of life and reduce early complications.