1. Botnar Research Centre (R.C.P., A.J.C., P.A.H.), Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Science, University of Oxford, Oxford OX3 7LD, United Kingdom
2. National Institute of Health Research Biomedical Research Unit (A.J.C., P.A.H.), Oxford, OX3 7LD, United Kingdom