1 Edinburgh Orthopaedics, Royal Infirmary of Edinburgh, Edinburgh, UK.
2 Department of Orthopaedics, Royal National Orthopaedic Hospital NHS Trust, London, UK.
3 Department of Orthopaedics, University College London Hospitals, The Princess Grace Hospital, and The NIHR Biomedical Research Centre at UCLH, London, UK.
4 The Bone & Joint Journal , London, UK.
5 Department of Orthopaedics and Trauma, University of Edinburgh, Edinburgh, UK.