1. Departments of Orthopedic and Neurological Surgery, NYU Langone Orthopedic Hospital, New York Spine Institute, New York, New York;
2. Departments of Orthopedics and Physical Rehabilitation, University of Massachusetts Chan Medical School, Worcester, Massachusetts;
3. Department of Neurological Surgery, Washington University, St. Louis, Missouri; and
4. Department of Neurological Surgery, Hoag Hospital Memorial Presbyterian, Newport Beach, California