1. Department of Spine Surgery, Second Military Medical University, Changzheng Hospital, Shanghai, China
2. Department of Spine Surgery, Hebei Medical University, The Third Hospital, Shijiazhuang, China
3. Department of Spine Surgery, Xi’an Jiaotong University and Xi’an Medical College, Xi’an Honghui Hospital, Xi ‘an, China
4. Department of Spine Surgery, Shanghai Jiaotong University, Renji Hospital, Shanghai, China
5. Department of Spine Surgery, Jilin University, The First Bethune Hospital, Changchun, China