1. Department of Neurosurgery, Montefiore Medical Center, New York, New York;
2. Departments of Neurosurgery and
3. Orthopedic Surgery, Spine Division, Duke University Medical Center, Durham, North Carolina;
4. Premier Health Orthopedics, Centerville, Ohio;
5. Department of Neurosurgery, Johns Hopkins School of Medicine, Baltimore, Maryland; and
6. Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts