1. The Southern California Orthopedic Institute, Van Nuys, California
2. Division of Sports Medicine, Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois
3. Orthopaedic Specialty Institute, Orange, California
4. Division of Sports Medicine, Department of Orthopedic Surgery, Missouri Orthopaedic Institute, University of Missouri, Columbia, Missouri
5. Division of Sports Surgery, Naval Medical Center San Diego, San Diego, California