1. Department of Orthopedic Surgery, Georgetown University Medical Center, Washington, DC, USA
2. Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
3. Department of Orthopedic Surgery, MedStar Union Memorial Hospital, Baltimore, MD, USA
4. Orthopedic and Neurosurgery Specialists Foundation, Greenwich, CT, USA
5. Washington Circle Orthopaedic Associates, Washington, DC, USA
6. Anderson Orthopedic Clinic, Arlington, VA, USA