1. Department of Orthopedics, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei, P. R. China
2. Department of Gynecology, Hebei Medical University Second Affiliated Hospital, Shijiazhuang, Hebei, P. R. China
3. Department of Orthopedics, The First Hospital of Shijiazhuang, Shijiazhuang, Hebei, P. R. China
4. Department of Pathology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei, P. R. China