1. Department of Orthopaedics Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang 050000, China
2. Basic Medical College, Hebei Medical University, Shijiazhuang 050017, China
3. Obstetrics and Gynecology Department, North China University of Science and Technology Affiliated Hospital, Tangshan 063000, China
4. Orthopaedic Institute of Hebei Province, Shijiazhuang 050000, China
5. Key Laboratory of Biomechanics of Hebei Province, Shijiazhuang 050000, China