1. Department of Orthopaedics, Blackpool Victoria Hospital, Whinney Heys Road, Blackpool, Lancashire, FY3 8NR, UK
2. Department of Radiology, Blackpool Victoria Hospital, Whinney Heys Road, Blackpool, Lancashire, FY3 8NR, UK
3. Gateshead Health NHS Foundation Trust, Queen Elizabeth Avenue, Gateshead, NE9 6SX, UK
4. School of Medicine, University of Central Lancashire, Fylde Road, Preston, Lancashire, PR1 2HE, UK