Atlanto-axial complex is the most important functional unit of the cervical spine.Atlanto-axial instability or dislocation,one of the most serious pathologies in spinal surgery,is often managed by posterior atlantoaxial fixation and fusion.Several posterior fixation techniques have been used to stabilize the atlanto-axial complex,including wire/cable-bone fixation,Halifax clamps,transarticular screw fixation,screw-plate fixation and screw-rod fixation.For atlanto-axial dislocation that cannot be reduced with skull traction before operation,intraoperative reduction is often needed.Current intraoperative reduction techniques can be classified into transoropharyngeal surgical release followed by posterior reduction and fixation,transoropharyngeal reduction and fixation,and posterior reduction and fixation using screw-rod system according to approaches.Furthermore,posterior reduction can be performed using elevating-pull,leverages,and cantilever techniques.This study reviews the intraoperative reduction and fixation techniques mentioned above.

Objective: To investigate of e-cigarette use among middle school students in Hainan Province, so as to provide insights into tobacco control among adolescents. Methods: Students were randomly sampled using a multistage stratified cluster random sampling method from three junior high schools, two high schools and one vocational high school in Hainan Province from July to October, 2021. Participants' basic features, use of e-cigarettes, e-cigarette advertising exposure were collected using the Questionnaire on Tobacco and Alcohol Prevalence among Chinese Adolescents in 2021 prepared by Chinese Center for Disease Control and Prevention. Following data weighting, students' use of e-cigarettes and exposure to e-cigarette advertisements were descriptively analyzed, and factors affecting current use of e-cigarettes were identified using a multivariable logistic regression model. Results: A total of 8 561 questionnaires were allocated, and 8 538 valid questionnaires were recovered, with an effective recovery rate of 99.73%. The respondents included 4 470 boys (52.35%) and 4 068 girls (47.65%), and there 4 367 junior high school students (51.15%), 3 482 high school students (40.78%), and 689 vocational high school students (8.07%). The rate of e-cigarette use was 25.01% and the rate of current e-cigarette use was 4.68%. There were 2 728 respondents with exposure to e-cigarette advertising during the past 30 days, and the number of weighted individuals were 210 932 (32.60%). The route of e-cigarette advertising exposure mainly included point-of-sale (21.59%), stores (13.61%), and shopping websites (9.01%). Multivariable logistic regression analysis identified region (OR=0.610, 95%CI: 0.482-0.772), males (OR=1.332, 95%CI: 1.062-1.669), high school students (OR=0.376, 95%CI: 0.259-0.545), companion smoking (OR=6.645, 95%CI: 4.935-8.948) and advertising exposure (OR=3.229, 95%CI: 2.581-4.040) as factors affecting current use of e-cigarettes. Conclusions The use of e-cigarettes among middle school students is higher in Hainan Province than the national level, and exposure to e-cigarette advertisements may facilitate use of e-cigarettes. It is necessary to strengthen the supervision of e-cigarettes, strictly restrict e-cigarettes advertisements and promotions.