1. Departments of Orthopedic Surgery and Anesthesiology, University of Maryland School of Medicine, Baltimore, MD, United States
2. Departments of Anesthesiology, Neurology, Physical Medicine & Rehabilitation, Psychiatry and Neurosurgery, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
3. Departments of Anesthesiology and Physical Medicine & Rehabilitation, Walter Reed National Military Medical Center, Uniformed Services University of the Health Sciences, Bethesda, MD, United States