1 NIHR-Leeds Musculoskeletal and Biomedical Research Center, Chapel Allerton Hospital, Leeds Teaching Hospital NHS Trust, Leeds, LS7 4SA, UK; Academic Department of Trauma and Orthopaedics, School of Medicine, University of Leeds, Leeds, LS1 3EX, UK. Electronic address: anthonyjhoward@aol.com.
2 Academic Department of Trauma and Orthopaedics, School of Medicine, University of Leeds, Leeds, LS1 3EX, UK.
3 NIHR-Leeds Musculoskeletal and Biomedical Research Center, Chapel Allerton Hospital, Leeds Teaching Hospital NHS Trust, Leeds, LS7 4SA, UK; Academic Department of Trauma and Orthopaedics, School of Medicine, University of Leeds, Leeds, LS1 3EX, UK.