[1] NYU Langone Med Ctr, Dept Orthopaed, Orthopaed Hosp, New York, NY USA
[2] Hosp Special Surg, Dept Orthopaed Surg, 535 E 70th St, New York, NY 10021 USA
[3] Univ Virginia Hlth Syst, Dept Neurosurg, Charlottesville, VA USA
[4] Presbyterian St Lukes Med Ctr, Denver Int Spine Ctr, Denver, CO USA
[5] Rocky Mt Hosp Children, Denver, CO USA
[6] Cedars Sinai Med Ctr, Dept Orthopaed Surg, Los Angeles, CA 90048 USA
[7] Univ Illinois, Dept Neurosurg, Chicago, IL 60680 USA
[8] Scripps Hlth, Dept Orthopaed Surg, La Jolla, CA USA
[9] Univ Calif San Francisco, Dept Orthopaed Surg, San Francisco, CA USA
[10] Brown Univ, Dept Orthopaed Surg, Med Ctr, Providence, RI 02912 USA
[11] Univ Michigan, Dept Neurosurg, Ann Arbor, MI 48109 USA
[12] Spine Inst Louisiana, Dept Orthoped Surg, Shreveport, LA USA
[13] Univ Calif Davis, Dept Orthoped Surg, Sacramento, CA 95817 USA
[14] Univ Kansas, Med Ctr, Dept Orthopaed Surg, Kansas City, KS 66103 USA
[15] Swedish Neurosci Inst, Dept Orthopaed Surg, Seattle, WA USA
[16] Univ Calif San Francisco, Dept Neurol Surg, San Francisco, CA USA