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