1. Institute of Orthopaedics and Musculoskeletal
Science, Division of Surgery and Interventional
Science, University College London, and
Royal National Orthopaedic Hospital Brockley Hill, Stanmore, Middlesex
HA7 4LP, UK.
2. University College London Hospitals, 235
Euston Road, London, NW1
2BU, UK and NIHR University College London
Hospitals Biomedical Research Centre, UK.