1. Salisbury District Hospital, Odstock Road, Salisbury, Wiltshire SP2 8BJ, UK.
2. Institute of Health and Biomedical Innovation, Queensland University of Technology, The Prince Charles Hospital, Brisbane, Queensland, Australia.
3. Exeter Hip Unit, Princess Elizabeth Orthopaedic Centre, Royal Devon & Exeter Hospital, Barrack Road, Exeter EX2 5DW, UK.