1. Kent & Sussex Hospital, 63 Mount Sion, Tunbridge Wells, Kent TN1 1TN, UK.
2. Department of Orthopaedics, Bristol Royal Infirmary, Bristol BS2 8HW, UK.
3. Department of Orthopaedics Salisbury District Hospital, Salisbury, Wiltshire SP2 8BJ, UK.
4. Department of Orthopaedics, St Mary’s Hospital, Praed Street, Paddington, London W2 1NY, UK.
5. Conquest Hospital, The Ridge, St, Leonards-on-Sea, East Sussex TN37 7RD, UK.
6. Spinal Unit, Ipswich Hospital, Heath Road, Ipswich IP4 5PD, UK.
7. Department of Trauma and Orthopaedics Kent and Sussex Hospital, Tunbridge Wells, Kent TN4 8AT, UK.