1. Thomas Jefferson University, Philadelphia, PA, USA
2. Indiana University, Indianapolis, IN, USA
3. Indiana Spine Group, Indianapolis, IN, USA
4. Boston University Medical Center, Boston, MA, USA
5. Northwestern University, Feinberg School of Medicine, Chicago, IL, USA
6. Kansas University Medical Center, Kansas City, KS, USA
7. Toronto Western Hospital, Toronto, Ontario, Canada
8. Cleveland Clinic, Cleveland, OH, USA
9. Boston University, Boston, MA, USA
10. Springfield Clinic, LLC, Springfield, IL, USA
11. Southern Illinois University, Springfield, IL, USA
12. Columbia University, New York, NY, USA
13. New York-Presbyterian/The Allen Hospital, New York, NY, USA