[1] NYU, Langone Med Ctr, Dept Neurosurg, New York, NY USA
[2] Shriners Childrens Philadelphia, 3551 N Broad St, Philadelphia, PA 19140 USA
[3] British Columbia Childrens Hosp, Dept Orthopaed, Vancouver, BC, Canada
[4] Nemours Alfred I DuPont Hosp Children, Wilmington, DE USA
[5] Mt Sinai Beth Israel Med Ctr, Dept Orthopaed Surg, New York, NY USA
[6] Johns Hopkins Childrens Ctr, Dept Orthopaed, Baltimore, MD USA
[7] Rady Childrens Hosp, San Diego, CA USA