[1] Columbia Univ Irving Med Ctr, Div Pediat Orthopaed Surg, Dept Orthopaed Surg, New York, NY USA
[2] New York Presbyterian Morgan Stanley Childrens Ho, Dept Pediat Orthopaed Surg, New York, NY USA
[3] Columbia Univ, Mailman Sch Publ Hlth, Dept Epidemiol, New York, NY USA
[4] Boston Childrens Hosp, Dept Orthoped Surg, Boston, MA USA
[5] Johns Hopkins Univ Hosp, Dept Orthopaed Surg, Baltimore, MD USA
[6] Prince Childrens Hosp, Dept Orthopaed Surg, Salt Lake City, UT USA
[7] Rainbow Babies & Childrens Hosp, Dept Orthopaed Surg, Cleveland, OH USA
[8] Seattle Childrens Hosp, Dept Orthoped & Sports Med, Seattle, WA USA