1. Spine Tumor Center, Department of Orthopedic Oncology, Changzheng Hospital, Second Military Medical University, Shanghai 200003, P.R. China
2. Department of Orthopedics, Hai'an People's Hospital, Jiangsu, Hai'an 226600, P.R. China
3. Department of Orthopedics, Taizhou People's Hospital, Jiangsu, Taizhou 225300, P.R. China