1. Departmant of Orthopaedics, Duke University, Durham, North Carolina
2. Department of Population Health Sciences, Durham, North Carolina
3. Duke Clinical Research Institute, Durham, North Carolina
4. Tripler Army Medical Center, Oahu, Hawaii
5. Department of Orthopaedic Surgery, Brooke Army Medical Center, San Antonio, TX
6. Naval Medical Center San Diego, San Diego, CA
7. Department of Rehabilitation Medicine, Brooke Army Medical Center, San Antonio, TX