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