1. Royal Orthopaedic Hospital, Birmingham B31 2AP, UK
2. Nuffield Orthopaedic Centre, Oxford OX3 7LD, UK
3. Freeman Hospital, Newcastle-upon-Tyne NE7 7DN, UK
4. The Royal Marsden, Sutton SM2 5PT, UK
5. Leeds Teaching Hospitals, LS9 7TF, UK
6. Birmingham Children’s Hospital, B4 6NH, UK
7. Queen Elizabeth Hospital, Birmingham B15 2TH, UK
8. University College Hospital, London NW1 2BU, UK