1. Department of Orthopaedics, Duke University, Durham, North Carolina;
2. Duke Clinical Research Institute, Duke University, Durham, North Carolina;
3. Department of Population Health Sciences, Durham, North Carolina;
4. Department of Neurosurgery, Carolina Neurosurgery and Spine Associates and Neuroscience Institute, Carolinas HealthCare System, Charlotte, North Carolina;
5. Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah;
6. Department of Neurosurgery, University of Virginia Health System, Charlottesville, Virginia;
7. Department of Neurologic Surgery, Mayo Clinic, Rochester, Minnesota;
8. Department of Neurological Surgery, University of California, San Francisco, California;
9. PPG Atlanta Brain and Spine Care, Atlanta, Georgia;
10. Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan;
11. Department of Neurosurgery, Duke University School of Medicine, Durham, North Carolina;
12. Barrow Neurological Institute, Phoenix, Arizona; and
13. Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida