[1] St Josephs Hosp, Barrow Neurol Inst, Dept Neurosurg, Phoenix, AZ 85013 USA
[2] Univ Miami, Miami Hosp, Dept Neurosurg, Miami, FL USA
[3] Scripps Clin, Div Orthopaed Surg, La Jolla, CA 92037 USA
[4] Univ Pittsburgh, Dept Neurol Surg, Med Ctr, Pittsburgh, PA USA
[5] Cedars Sinai Med Ctr, Dept Neurosurg, Los Angeles, CA 90048 USA
[6] Univ Michigan, Dept Neurosurg, Ann Arbor, MI 48109 USA
[7] Univ Virginia, Med Ctr, Dept Neurosurg, Charlottesville, VA USA
[8] Univ Kansas, Med Ctr, Dept Orthoped Surg, Kansas City, KS 66103 USA
[9] Univ Calif San Francisco, Dept Neurosurg, San Francisco, CA USA
[10] Rady Childrens Hosp San Diego, Div Orthoped & Scoliosis, San Diego, CA USA
[11] Hosp Special Surg, Dept Orthoped, 535 E 70th St, New York, NY 10021 USA
[12] Denver Int Spine Ctr, Denver, CO USA
[13] Duke Univ, Dept Neurosurg, Durham, NC USA
[14] Columbia Univ, Spine Hosp, Dept Orthoped Surg, New York, NY USA