1. Department of Orthopaedic Surgery, University of Edinburgh, Royal Infirmary of Edinburgh, Little France, Edinburgh EH16 4SU, UK.
2. Orthopaedic Department, 307 Hospital of the Peoples’ Liberation Army, 8 Dongdajie, Beijing, 10071, China.
3. 47 Braemar Place, Aberdeen AB10 6EN, UK.
4. University of Edinburgh, Old College, South Bridge, Edinburgh EH8 9YL, UK.