1. Department of Trauma and Orthopaedic Surgery, Lister Hospital, Stevenage, UK
2. Department of Trauma and Orthopaedic Surgery, The Royal London Hospital, London, UK
3. Department of Trauma and Orthopaedic Surgery, Sandwell and West Birmingham Hospitals, West Bromwich, West Midlands, UK
4. Department of Trauma and Orthopaedic Surgery, The Royal Orthopaedic Hospital, Birmingham, UK