1. Department of Obstetrics and Gynaecology, North Manchester General Hospital, Manchester, UK
2. Department of Trauma and Orthopaedics, Rotorua Hospital, Rotorua, New Zealand
3. Department of Trauma and Orthopaedics, Whipps Cross University Hospital NHS Trust, London, UK
4. Department of Trauma and Orthopaedics, Barts Health NHS Trust, The Royal Hospital, London, UK