1. Department of Pain Medicine, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830054, P.R. China
2. Department of Gynecology, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830054, P.R. China
3. Department of Orthopaedics, Yili Friendship Hospital, Yining, Xinjiang 835000, P.R. China