*Department of Anesthesia†Department of Clinical Epidemiology and Biostatistics‡Department of Family Medicine§Faculty of Health Sciences¶Department of Oncology[BULLET OPERATOR]Department of Surgery, McMaster University, Hamilton, Ontario, Canada**Department of Orthopaedics, University of British Columbia, Combined Neurosurgical and Orthopaedic Spine Program, Vancouver Hospital and Health Sciences Centre, Vancouver, British Columbia, Canada††Ottawa Hospital, Ottawa, Ontario, Canada‡‡Ontario Chiropractic Association, Toronto, Ontario, Canada§§School of Population and Public Health, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada¶¶International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada[BULLET OPERATOR][BULLET OPERATOR]Department of Surgery, Divisions of Orthopedic Surgery and Neurosurgery, University of Toronto, Toronto, Ontario, Canada.