1. Spine Service, Department of Orthopaedic Surgery, St. George & Sutherland Clinical School University of New South Wales Sydney New South Wales Australia
2. Raymond Purves Bone and Joint Research Laboratory Kolling Institute, Sydney University Faculty of Medicine and Health, Northern Sydney Area Health District, Royal North Shore Hospital Sydney New South Wales Australia
3. Graduate School of Biomedical Engineering The University of New South Wales Sydney New South Wales Australia