1Department of Radiology, The Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex, HA7 4LP, UK
2Department of Orthopaedic Surgery, The Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex, HA7 4LP, UK
3Institute of Orthopaedics & Musculoskeletal Sciences, The Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex, HA7 4LP, UK