1. Scripps Clinic Medical Group, San Diego, CA 92037, USA
2. Aichi Spine Hospital, Aichi, Inuyama 484-0066, Japan
3. Mayo Clinic College of Medicine and Science, Rochester, NY 55905, USA
4. San Diego Department of Orthopaedic Surgery, University of California, La Jolla, CA 92093, USA
5. San Diego Spine Foundation, San Diego, CA 92121, USA
6. Barrow Neurological Institute, Phoenix, AZ 85013, USA