[1] Univ British Columbia, Combined Neurosurg & Orthopaed Spine Program, Vancouver, BC, Canada
[2] Canadian Spine Soc, Toronto, ON, Canada
[3] Univ Calgary, Dept Clin Neurosci, Calgary, AB, Canada
[4] Univ Manitoba, Dept Surg, Sect Orthopaed & Neurosurg, Winnipeg, MB, Canada
[5] Western Univ, Dept Surg, London, ON, Canada
[6] Dalhousie Univ, Div Neurosurg, Halifax, NS, Canada
[7] Ctr Hosp Univ Quebec, Dept Orthopaed, Quebec City, PQ, Canada
[8] Univ Alberta, Fac Med & Dent, Div Neurosurg, Edmonton, AB, Canada
[9] Univ Toronto, Dept Surg, Div Neurosurg, Toronto, ON, Canada
[10] St Johns Hosp, Canada East Spine Ctr, New Brunswick, NJ USA
[11] Univ Toronto, Dept Surg, Toronto, ON, Canada
[12] Univ Toronto, Dept Surg, Div Orthopaed Surg & Neurosurg, Toronto, ON, Canada