[1] Univ Sydney, Fac Med & Hlth, Charles Perkins Ctr, Sydney Musculoskeletal Hlth,Sch Hlth Sci, Sydney, NSW 2050, Australia
[2] Univ Sydney, Sydney Musculoskeletal Hlth, St Leonards, NSW 2065, Australia
[3] Northern Sydney Local Hlth Dist, Kolling Inst, Fac Med & Hlth, Sch Hlth Sci, St Leonards, NSW 2065, Australia
[4] NeuroSpine Surg Res Grp NSURG, Sydney, NSW 2031, Australia
[5] Prince Wales Hosp, Barker St, Randwick, NSW 2031, Australia
[6] Univ New South Wales, Sch Med Sci, Sydney, NSW, Australia
[7] Concord Repatriat Gen Hosp, Dept Neurosurg, ConcordConcord, NSW 2139, Australia
[8] Sydney Spine Inst, Burwood, NSW 2134, Australia
[9] Univ New South Wales, Sch Clin Med, South West Sydney Clin Campuses, UNSW Med & Hlth, Sydney, NSW 2170, Australia
[10] Cabrini & Austin Hosp, Neurosurg, Melbourne, Vic 3800, Australia
[11] Univ Sydney, Fac Med & Hlth, NHMRC CTC, Sydney, Australia
[12] Univ Sydney, Sydney Musculoskeletal Hlth, Sydney, NSW 2050, Australia
[13] Univ Sydney, Fac Med & Hlth, Sch Hlth Sci, Sydney, NSW 2050, Australia
[14] Monash Univ, Sch Publ Hlth & Prevent Med, Melbourne, Vic 3800, Australia
[15] Monash Univ, Sch Publ Hlth & Prevent Med, Musculoskeletal Hlth & Wiser Hlth Care Units, Melbourne, Vic 3004, Australia