Affiliation

• ¹ *Departments of Orthopaedic Surgery and Neurological Surgery, Thomas Jefferson University and The Rothman Institute, Philadelphia, PA †Division of Spine, Department of Orthopaedics, University of British Columbia, Vancouver, British Columbia, Canada ‡Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT §Department of Orthopaedic Surgery and Rehabilitation, Northwestern University School of Medicine, Chicago, IL ¶Departments of Surgery and Clinical Neurosciences, University of Calgary, Alberta, Canada ‖British Columbia Children's Hospital, Vancouver, British Columbia, Canada **Department of Neurological Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and ††Departments of Neurological Surgery and Orthopaedic Surgery, Thomas Jefferson University, Philadelphia, PA.