1. S. Namdari, MD, is Orthopaedic Surgery Resident, Department of Orthopaedic Surgery, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
2. S.G. Pill, PT, MD, MSPT, is Orthopaedic Surgery Resident, Department of Orthopaedic Surgery, Hospital of the University of Pennsylvania.
3. A. Makani, MD, is Orthopaedic Surgery Resident, Department of Orthopaedic Surgery, Hospital of the University of Pennsylvania.
4. M.A. Keenan, MD, is Chief, Neuro-Orthopaedics Program, and Professor and Vice Chair for Graduate Medical Education, Department of Orthopaedic Surgery, Hospital of the University of Pennsylvania, 3400 Spruce St, 2 Silverstein, Philadelphia, PA 19104 (USA).