1. Department of Orthopaedic Surgery, New York University/Hospital for Joint Diseases;
2. NuVasive, Inc., San Diego, California;
3. Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, New York;
4. Department of Neurosurgery, University of Virginia Medical Center, Charlottesville, Virginia; and
5. Atlanta Brain and Spine Care, Atlanta, Georgia