[1] Alfred I duPont Hosp Children, Dept Med Imaging, Nemours Childrens Clin, Wilmington, DE 19899 USA
[2] Alfred I duPont Hosp Children, Dept Pediat, Nemours Childrens Clin, Wilmington, DE 19899 USA
[3] Alfred I duPont Hosp Children, Nemours Biomed Res, Nemours Childrens Clin, Wilmington, DE 19899 USA
[4] Alfred I duPont Hosp Children, Dept Orthopaed, Nemours Childrens Clin, Wilmington, DE 19899 USA
[5] Univ N Carolina, Dept Pediat, Chapel Hill, NC USA
[6] Univ N Carolina, Dept Orthoped, Chapel Hill, NC USA