1. Department of Neurological Surgery, Weill Cornell Medical College, New York, New York;
2. Department of Neurosurgery, Tufts Medical Center and Floating Hospital for Children, Boston, Massachusetts;
3. Shriners Hospitals for Children—Philadelphia;
4. Department of Neurosurgery, University of Pennsylvania; and
5. Department of Orthopaedic Surgery, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania