1. Department of Orthopedic Surgery, Vanderbilt University Medical Center, Nashville, TN
2. Center for Musculoskeletal Research, Vanderbilt University Medical Center, Nashville, TN
3. Department of Neurosurgery, Vanderbilt University Medical Center, Nashville, TN
4. Neuroscience Institute, Atrium Health and Department of Neurosurgery, Carolinas Medical Center, Charlotte, North Carolina; Carolina Neurosurgery and Spine Associates, Charlotte, NC