1. Orthopaedic Department, Frenchay Hospital, Frenchay Park Road, Bristol BS16 1LE, UK.
2. Trauma and Orthopaedic Department, Royal Orthopaedic Hospital, Northfield, Birmingham B31 2AP, UK.
3. Department of Orthopaedic Surgery, Nuffield Orthopaedic Centre, Windmill Road, Oxford OX3 7LD, UK.
4. Ngwelezane Hospital, P/Bag X20021, Empangeni 3880, KwaZulu-Natal, South Africa.