1. Department of Traumatic Orthopaedics, Weifang People's Hospital, Weifang, Shandong 261000, P.R. China
2. Department of Internal Medicine, Zhucheng BaiChiHe Hospital, Zhucheng, Shandong 262217, P.R. China
3. Department of Anesthesiology, Weifang People's Hospital, Weifang, Shandong 261000, P.R. China