1. School of Medicine, Shandong University, Ji’nan, China;
2. Department of Orthopedics, Qilu Hospital, Shandong University, Ji’nan, China;
3. Department of Orthopedics, East Hospital of Shouguang People's Hospital, Weifang, China;
4. Department of Orthopedics, Shandong Tai'an Coal Mine Hospital, Tai'an, China;
5. Department of Spine Surgery, Tengzhou Central People’s Hospital, Tengzhou, China;
6. College of Physics and Electronic Sciences, Shandong Normal University, Ji’nan, China