[1] Univ British Columbia, Dept Orthoped Surg, Combined Neurosurg & Orthoped Spine Program, Vancouver, BC, Canada
[2] Canadian Spine Soc, Markdale, ON, Canada
[3] Univ Alberta, Div Neurosurg, Edmonton, AB, Canada
[4] Dalhousie Univ, Dept Surg, Halifax, NS, Canada
[5] Univ Toronto, Sunnybrook Hlth Sci Ctr, Dept Surg, Spine Program, Toronto, ON, Canada
[6] Univ Ottawa, Div Orthopaed Surg, Ottawa, ON, Canada
[7] Univ Montreal, Dept Orthoped Surg, Hlth Ctr, Montreal, PQ, Canada
[8] Western Univ, London Hlth Sci Ctr Combined Orthopaed, Schulich Sch Med, London, ON, Canada
[9] Western Univ, Schulich Sch Med, Neurosurg Spine Program, London, ON, Canada
[10] Canada East Spine Ctr, Div Orthopaed, St John, NB, Canada
[11] Univ Laval, Ctr Rech CHU Quebec, CHU Quebec, Quebec City, PQ, Canada
[12] Univ Toronto, Univ Hlth Network, Schroeder Arthrit Inst, Orthopaed,Dept Surg,Div Orthopaed Surg,Krembil Res, Toronto, ON, Canada