1. South West London Elective Orthopaedic Centre, Epsom General Hospital, Dorking Road, Epsom, Surrey KT18 7EG, UK.
2. Oxford Rotation, Nuffield Orthopaedic Centre, Windmill Road, Headington, Oxford OX3 7LD, UK.
3. Orthopaedic Research Unit, St Helier Hospital, Epsom and St Helier University Hospitals NHS Trust, Wrythe Lane, Carshalton, Surrey SM5 1AA, UK.