1. Department of Orthopaedics, Royal National Orthopaedic NHS Trust, London, UK
2. Department of Orthopaedics, Royal Free London NHS Trust, London, UK
3. Barts Heart Centre, Barts Health NHS Trust, London, UK
4. Department of Orthopaedics, Mid and South Essex NHS Trust, Basildon, UK
5. Department of Orthopaedics, Barts Health NHS Trust, London, UK