1. Department of Orthopaedics, University College London Hospitals, London, UK
2. Barcelona Graduate School of Economics, Barcelona, Spain
3. Department of Nursing, Midwifery and Health, Northumbria University, Northumbria, UK
4. Department of Orthopaedics, Royal Infirmary of Edinburgh, Edinburgh, UK
5. Department of Orthopaedics, Freeman Hospital, Newcastle, UK