1. Department of Neurosurgery, Wessex Neurological Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK;
2. Division of Clinical Neurosciences, School of Medicine, University of Southampton, Southampton, UK;
3. Department of Orthopaedic Surgery, University Hospital Southampton NHS Foundation Trust, Southampton, UK;
4. Department of Musculoskeletal Radiology, University Hospital Southampton NHS Foundation Trust, Southampton, UK