[1] Univ Oxford, Nuffield Dept Orthopaed Rheumatol & Musculoskelet, Oxford, England
[2] UCL, London, England
[3] Univ Cambridge, Addenbrookes Hosp, Cambridge CB2 2QQ, England
[4] Kings Coll London, London WC2R 2LS, England
[5] Univ Aberdeen, Aberdeen, Scotland
[6] Cork Univ Hosp, Cork, Ireland
[7] Manchester Royal Infirm, Manchester M13 9WL, Lancs, England
[8] Nottingham Univ Hosp NHS Trust, Nottingham, England
[9] Univ Hosp Aintree Liverpool, Liverpool, Merseyside, England
[10] Trinity Coll Dublin, Dublin, Ireland
[11] Ipswich Hosp NHS Trust, Ipswich, Suffolk, England
[12] Oxford NIHR Musculoskeletal Biomed Res Unit, Oxford, England