1. Department of Spinal Surgery, Affiliated Hospital of Jining Medical University, Jining, Shandong 272029, P.R. China
2. Department of Spine Surgery, People's Hospital of Rizhao, Rizhao, Shandong 276800, P.R. China
3. Imaging Department, Affiliated Hospital of Jining Medical University, Jining, Shandong 272029, P.R. China