1. Sports Medicine Department, Beijing Key Laboratory of Sports Injuries, Peking University Third Hospital, Beijing, China.
2. Institute of Sports Medicine of Peking University, Beijing, China.
3. Department of Orthopedic Surgery, Sports Medicine and Arthroscopy, University of California, Davis, Sacramento, California, USA.
4. Peking University First Hospital, Beijing, China.
5. Research Center of Clinical Epidemiology, Peking University Third Hospital, Beijing, China.