1. Department of Neurological Surgery, Columbia University, The Och Spine Hospital at NewYork-Presbyterian, New York, New York;
2. Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota;
3. Department of Neurological Surgery, University of Utah, Salt Lake City, Utah;
4. Orthopedic Surgery, Norton Leatherman Spine Center, Louisville, Kentucky;
5. Department of Neurological Surgery, University of Tennessee, Semmes-Murphey Neurologic and Spine Institute, Memphis, Tennessee;
6. Departments of Neurosurgery and Orthopedic Surgery, Duke University, Durham, North Carolina;
7. Neurosurgery, Goodman Campbell Brain and Spine, Indianapolis, Indianapolis;
8. Department of Neurological Surgery, University of Virginia, Charlottesville, Virginia;
9. Neurosurgery, Neuroscience Institute, Carolinas Healthcare System and Carolina Neurosurgery & Spine Associates, Charlotte, North Carolina;
10. Neurosurgery, Atlantic Neurosurgical Specialists, Morristown, New Jersey;
11. Department of Neurological Surgery, University of Miami, Florida;
12. Department of Neurological Surgery, Weill Cornell Medical Center, New York, New York;
13. Neurosurgery, Geisinger Neuroscience Institute, Danville, Pennsylvania;
14. Neurosurgery, Atlanta Brain and Spine Care, Atlanta, Georgia;
15. Department of Neurological Surgery, University of California, San Francisco, California; and
16. Duke University School of Medicine, Durham, North Carolina