1. Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, USA
2. Department of Orthopaedic Surgery, San Antonio Military Medical Center, San Antonio, Texas, USA
3. Department of Orthopedics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
4. Department of Orthopaedic Surgery, Duke University, Durham, North Carolina, USA
5. Department of Orthopaedic Surgery, 10th Medical Group, US Air Force Academy, Colorado Springs, Colorado, USA