1. Department of Neurosurgery, The Johns Hopkins Hospital, Baltimore, Maryland, USA;
2. Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA;
3. Neurosurgery, University of Kansas Medical Center, Kansas City, Kansas, USA;
4. Department of Neurosurgery, Rush University Medical Center, Chicago, Illinois, USA;
5. Current Affiliation: Orange County Neurosurgical Associates, Laguna Hills, California, USA
6. Department of Neurological Surgery, Thomas Jefferson University Hospitals, Philadelphia, Pennsylvania, USA;
7. Musculoskeletal Education and Research Center, A Division of Globus Medical, Inc., Audubon, Pennsylvania, USA;
8. School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, Pennsylvania, USA;