1. Department of Orthopedic Surgery, Stanford University, Stanford, California, USA.
2. Veterans Administration Hospital–Palo Alto, Palo Alto, California, USA.
3. Houston Methodist Orthopedics and Sports Medicine, Houston, Texas, USA.
4. Florida Orthopedic Institute, Tampa, Florida, USA.
5. Orthopedic Institute, Holy Cross Hospital, Fort Lauderdale, Florida, USA.
6. Department of Orthopedic Surgery, Rush University, Chicago, Illinois, USA.