1. George Washington University School of Medicine, Washington, DC
2. Department of Orthopaedic Surgery, William Beaumont Army Medical Center, El Paso, Texas, USA
3. Department of Orthopaedic Surgery, Carthage Area Hospital, Carthage, New York, USA
4. Department of Orthopaedic Surgery, Claxton-Hepburn Medical Center, Ogdensburg, New York, USA