1. Huddersfield Royal Infirmary, Acre Mill, Lindley, Huddersfield HD3 3EA, UK.
2. Health Services Research, School of Medicine University of Wales, Singleton Park, Swansea SA2 8PP, UK.
3. Department of Trauma and Orthopaedics, Ngwelezane Hospital, Private Bag X20021, Empangeni 3880, Kwa-Zulu-Natal, South Africa.