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