In order to investigate the mechanical response of lumbar vertebrae during gait cycle in adolescents with idiopathic scoliosis (AIS), the present study was based on computed tomography (CT) data of AIS patients to construct model of the left support phase (ML) and model of the right support phase (MR), respectively. Firstly, material properties, boundary conditions and load loading were set to simulate the lumbar vertebra-pelvis model. Then, the difference of stress and displacement in the lumbar spine between ML and MR was compared based on the stress and displacement cloud map. The results showed that in ML, the lumbar stress was mostly distributed on the convex side, while in MR, it was mostly distributed on the concave side. The stress of the two types of stress mainly gathered near the vertebral arch plate, and the stress of the vertebral arch plate was transmitted to the vertebral body through the pedicle with the progress of gait. The average stress of the intervertebral tissue in MR was greater than that in ML, and the difference of stress on the convex and convex side was greater. The displacement of lumbar vertebrae in ML decreased gradually from L1 to L5. The opposite is true in MR. In conclusion, this study can accurately quantify the stress on the lumbar spine during gait, and may provide guidance for brace design and clinical decision making.
Humans ; Lumbar Vertebrae/diagnostic imaging* ; Scoliosis/diagnostic imaging* ; Adolescent ; Gait/physiology* ; Biomechanical Phenomena ; Tomography, X-Ray Computed ; Stress, Mechanical ; Female ; Male

Objective To investigate the prevalence of scoliosis and congenital heart disease(CHD)and their correlation among children and adolescents of Drung nationality in Yunnan Province.Methods A cross-sectional survey was conducted in November 2022 among all Drung school-aged children and adolescents aged 5-18 years in Gongshan Drung and Nu Autonomous County,Yunnan Province.Visual inspection,Adams for-ward flexion test,and trunk rotation angle(ATR)measurement were comprehensively used for school prelim-inary screening of scoliosis.Individuals who tested positive in the school preliminary screening underwent fur-ther X-ray examination for auxiliary diagnosis.Cardiac auscultation and echocardiography were used for school preliminary screening of CHD.The personal information of the screening subjects,the screening results,etc.were recorded.The prevalence of scoliosis and CHD among children and adolescents of the Drung nationality and the relationship between the two diseases were statistically analyzed,and the positive predictive value of school-based scoliosis screening and its influencing factors were also analyzed.Results A total of 1 036 chil-dren and adolescents of Drung nationality were enrolled,with a mean age of(10.72±3.75)years,icluding 542 males and 494 females.A total of 45 subjects tested positive for scoliosis in the school preliminary screening,with a preliminary positive rate of 4.34%.A total of 22 cases were finally diagnosed with scoliosis,with a prevalence rate of 2.12%.Among them,21 cases were idiopathic scoliosis(accounting for 95.45%),and 1 case was congenital scoliosis(accounting for 4.55%).The prevalence rate was higher in females(2.83%)than that in males(1.48%),higher in the 10 to 18-year-old group(2.30%)than that in the 5 to<10-year-old group(1.87%),and higher in the secondary school group(2.78%)than that in the primary school group(1.78%),hut there were no statistically significant differences(P>0.05).Most idiopathic scoliosis cases were mild(Cobb angle 10° to<20°,90.48%)and classified as Lenke type Ⅴ(57.14%).Two cases of CHD were confirmed,both of which were atrial septal defects,with a prevalence rate of 0.19%.The co-occurrence rate of idiopathic scoliosis and CHD was 4.76%(1/21).The positive predictive value of school-based scoliosis pre-liminary screening was only 48.89%.When the BMI was<18.5 kg/m2,the positive predictive value was sig-nificantly higher than that for BMI≥18.5 kg/m2(P<0.05).Conclusion The prevalence rate of scoliosis a-mong adolescents of the Drung ethnic group in Yunnan Province is 2.12%,predominantly idiopathic scoliosis,with Lenke type V being the most common classification.The prevalence rate of congenital heart disease is 0.19%.BMI is a significant influencing factor for the positive predictive value of school-based scoliosis prelimi-nary screening.

Objective To study the changes and mechanism of skin stem cells in microgravity.Methods The skin stem cells of SD rats were used to establish a suspension culture system and compare the proliferation of skin stem cells with 1G gravity.Results The simulated microgravity significantly affected the velocity of skin stem cell sphere proliferation in suspension culture,which was about 12%higher than the 1G gravity group.Transcriptome sequencing showed that 1673 genes were up-regulated and 1409 genes were downregulated;Calcium signaling;cytokine-cytokine receptor interaction and PPAR pathway were different in the two environments.Conclusion Simulation of microgravity can affect the proliferation behavior of skin stem cells in suspension culture by regulating the expression of key signaling pathways,which provides an experimental basis for further research in spatial microgravity environ ment.

Objective:To investigate the epidemiological characteristics and influencing factors of scoliosis among primary and middle school students in Dali Bai autonomous prefecture.Methods:A total of 176,729 students aged 6-18 years from 380 primary and secondary schools in eight counties of Dali Bai Autonomous Prefecture were screened for spinal health by visual method, Adams forward bend test and scoliometer measuring the angle of trunk rotation from September to November 2021. The angle of trunk rotation ≥5° or visual method retest positive was used as a positive standard to confirm suspected scoliosis population. Demographic data of the screening population including name, gender, age and ethnicity were collected. The average altitude of the community or village committee in the screening area was recorded. Binary logistic regression analysis was used to screen the influencing factors of scoliosis.Results:There were 176,729 people planned to complete the screening. A total of 140,026 people were actually completed screening with completion rate 79.23%. A total of 3,190 (2.28%) suspected scoliosis positive people were detected. The detection rate of female was 2.52%, which was higher than that of male 2.03% (χ 2=37.18, P<0.001). The detection rate of 10-18 years old group was 2.90%, which was higher than that of 6-9 years old group 0.70% (χ 2=620.79, P<0.001). There was a significant difference in the detection rate among different age groups from 6 to 18 years old (χ 2=1,451.00, P<0.001). The detection rate of Han population was 2.67%, which was higher than that of non-Han population 2.15% (χ 2=31.06, P<0.001). In non-Han population, the detection rate of Bai population was 2.07%, which was lower than that of non-Bai population 2.26% (χ 2=4.02, P=0.045). Trend chi-square test showed significant difference in the detection rate of scoliosis among the general population, 10-18 years old population and 6-9 years old population in the altitude <1,500 m, 1,500-1,599 m, 1,600-1,699 m, 1,700-1,799 m, 1,800-1,899 m, 1,900-1,999 m, 2,000-2,099 m, 2,100-2,199 m, 2,200-2,299 m and ≥2,300 m groups (χ 2=249.02, 195.64, 24.46, P<0.05). Binary logistic regression analysis showed that the risk of scoliosis was lower in males than that in females ( OR=0.82, P<0.001). The risk of scoliosis was increased in 10-18 years old compared with that in 6-9 years old ( OR=0.12, P<0.001). The risk of scoliosis was low in Bai population compared with that in Han populations ( OR=0.75, P<0.001). The altitude ≥2,000 m was a risk factor ( OR=1.52, P<0.001). Conclusion:The detection rate of suspected scoliosis in primary and middle school students in Dali Bai Autonomous Prefecture was 2.28%. Female, aged 10-18 years, Han populations, and residence in altitude ≥2,000 m might be the risk factors for scoliosis.

ObjectiveTo analyze the risk factors related to perforation of lateral wall by lower cervical pedicle screw instrumentation in the treatment of cervical spinal disorders. MethodsA retrospective review was made to analyze 214 cervical vertebral injury patients ( 1 024 pedicle screws were used) treated with pedicle screw instrumentation at C3-7 from July 2004 to July 2009. Lateral walls of 18 patients were perforated (a total of 28 pedicle screws). The surgeons assessed the position and the angle of the screw in the pedicle, and the relation and the distance between the screw and the pedicle walls by carefully probing intraoperative walls of cervical pedicles and studying postoperative thin-slice computed tomography (CT) scan of the fixed vertebral segments of the cervical spine. The data of patients with lateral wall perforation was recorded and analyzed statistically. ResultsPerforation of the lateral wall occurred in 18 patients (28 pedicle screws). Backward step by step Logistic regression analysis was used and two variables were selected in the end. ConclusionsRatio variance between inner and lateral wall is the risk factor of perforation in the lateral wall associated with lower cervical pedicle screw instrumentation, while the angle variance between implanted screws and CT measurements is the protection factor of perforation in the lateral wall.

Objective To analyze the complications of lower cervical pedicle screw fixation in treatment of the cervical spine disorders and discuss the operative technique. Methods A retrospective study was made in 104 patients with different cervical injuries treated by C3-7 pedicle screw fixation (total use of 624 screws) from July 2004 to March 2008. One stage posterior reduction and fixation using lower cervical pedicle screw-rod system or screw-plat system were performed in 66 traumatic patients and the nerve condition was evaluated by Frankel criteria system. For 46 non-traumatic patients, laminoplasty or laminectomy was performed for decompression, and cervical pedicle screw-rod system or screw-plat system were used in deformity correction and stability reconstruction. Based on exploration to quadric walls of vertebral pedicle during operation, postoperative thin-slice CT scan along operative vertebra segments' pedicle and bilateral oblique position X-ray of cervical spine in all patients, we evaluated screw location, screw angle as well as the distance and the relation between the screws and the internal pedicle wall or lateral wall. Results In this study, the lower cervical pedicles of 104 patients were fixated with 624 screws including 77 screws (12.34% ) for pedicle wall damage, 68 screws (10.8% ) for the lateral wall injury, 56 screws (8.97% ) for grade Ⅰ violation of pedicles, 12 screws (1.92% ) for grade II violation of pedicles Ⅱ violation of pedicles and 9 screws (1.44% ) for inferior wall injury of cervical pedicle. The follow-up lasted for 3-24 months (average 9. 8 months), which showed breakage of two screws (0.32% ) and loosening of one screw (0.16% ). Conclusions Lower cervical pedicle screw fixation has relatively low incidence of complications and is a safe operation. The complications can be minimized by sufficient preoperative imaging studies of the pedicles, familiar with the feature of opography and reasonable surgery technique.