1. Department of Orthopaedics, University of British Columbia, Vancouver, British Columbia, Canada
2. Clinical Prevention Services, BC Centre for Disease Control, Vancouver, British Columbia, Canada
3. Department of Orthopaedic Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA
4. Department of Surgery, University of Toronto, Toronto, Ontario, Canada
5. Department of Orthopedic Surgery, Dalhousie University, Halifax, Nova Scotia, Canada
6. Division of Orthopaedic Surgery, Vancouver Island Health Authority, Victoria, British Columbia, Canada
7. Centre for Health Services and Policy Research, School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada