1. Department of Orthopaedics and Trauma, Cheltenham General Hospital, Sandford Road, Cheltenham GL53 7AN, UK.
2. Department of Orthopaedics and Trauma, Frenchay Hospital, Beckspool Road, Frenchay, Bristol BS16 1JE, UK.
3. Southmead Hospital, Southmead, Bristol BS10 5NB, UK.