INVESTIGATING HOW BONE HEALTH INFLUENCES OUTCOME FOLLOWING CELL THERAPY FOR CARTILAGE DEFECTS IN THE KNEE

Helen McCarthy, Berhard Tins, Paul Jermin, Martyn Snow, Chadi Rakieh, Jan Herman Kuiper and Karina Wright

Funded by the Orthopaedic Institute and the Michael Davie Research Foundation

Osteoarthritis (OA) is a common condition characterised by pain and loss of joint function and has led to the development of cell-based therapies aimed at reducing symptoms and delaying the need for a joint replacement when used early enough. Frequently referred to as a “cartilage problem”, OA is in fact a degenerative condition of the whole joint and therefore impacts many different tissue types/structures, such as the bone beneath the cartilage (see picture insert). Some areas of bone show damage to its structure; this can be detected on MRI scans and has been found to be associated with pain and joint degeneration. These damaged areas of bone are called bone marrow lesions (BMLs) and recently they have been identified as a potential marker of OA severity. Changes in biomarkers associated with bone health have also been found in patients with either BMLs and/or OA pathology. Given that the bone in joints is required to support the health of the cartilage, one must question how the health of the underlying bone affects the success of cell-based therapies for cartilage repair.

This retrospective study aims to identify the presence and severity of BMLs and levels of bone-related biomarkers in patients who have previously received cell therapy treatment for cartilage defects in their knee and measure whether they relate to the success of their treatment. We are using patients’ scans, questionnaires, tissue/fluid samples and data previously consented for research, collected from the aforementioned patient cohort for this project. This project has the potential not only to indicate which patients are suitable for such cell therapy and more likely to have a good outcome but also indicate those patients that may benefit from an additional treatment to treat their BMLs. In terms of patient impact, if an association is observed between BML presence and severity and the success of the cell therapy treatment, then clinicians may be able to identify which patients are most suited for cell-based therapies at an earlier stage in their treatment. This could ultimately lead to better patient treatment outcomes, less patient risk/burden, and potentially cheaper costs for the NHS. In addition, future treatments can be better tailored to target BMLs at the time of cell therapy, improving overall outcomes for patients and perhaps the progression of osteoarthritis and its symptoms, particularly the pain associated with these areas of bone damage.