1. Wallace Clinical Trials Center, Greenwich, Connecticut
2. Connecticut Spine Institute, Greenwich, Connecticut
3. Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut
4. Dartmouth College, Hanover, New Hampshire
5. The Center for Spine Health and Department of Neurosurgery, Cleveland Clinic Foundation, Cleveland, Ohio
6. Yale Center for Clinical Investigation, Yale University School of Medicine, New Haven, Connecticut
7. Department of Neurosurgery, Lahey Clinic, Burlington, Massachusetts
8. Department of Neurosurgery, University of Utah Health Sciences Center, Salt Lake City, Utah
9. Department of Neurosurgery, Danbury Hospital, Danbury, Connecticut
10. Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts
11. Department of Neurosurgery, Mt. Sinai Hospital, New York, New York
12. Section of Neurosurgery, VA Connecticut Healthcare System, West Haven, Connecticut
13. Department of Neurosurgery, University of Medicine and Dentistry of New Jersey–New Jersey Medical School, Newark, New Jersey