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Purpose To evaluate the short-term effects of different conservative treatments on in adolescent idiopathic scoliosis. Methods By searching the relevant literature of adolescent idiopathic scoliosis, the curative effects of the three regimens of bracing therapy combined with scoliosis-specific exercises, simple treatment with brace and simple scoliosis-specific exercises were compared. Review manager 5.3, Stata MP16 and Network software packages were used for Reticular Meta-analysis of Cobb’s angles before and after treatment. Results A total of 364 patients were included in four clinical studies. Reticular meta-analysis showed that the short-term effect of bracing treatment combined with scoliosis-specific exercises was better than that of treatment with brace and scoliosis-specific exercises, with effects of 2.71(95% CI 0.83–4.58) and 3.67(95% CI 1.21–6.14), respectively. There was no statistical difference between simple bracing therapy and scoliosis-specific exercises. Conclusion Among the three common conservative treatments of adolescent idiopathic scoliosis, the short-term effect of bracing treatment combined with scoliosis-specific exercises is better than that of bracing treatment or scoliosis-specific exercises.

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Background To identify the pelvic parameters affecting in-brace correction (IBC) in patients with idiopathic scoliosis (IS). Methods Patients with IS receiving Chêneau brace treatment in our scoliosis center from January 2019 to November 2019 were retrospectively analyzed. Pelvic rotation parameters, including pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), L/R ratio, were collected. Other radiographic data, such as Risser sign, coronal and sagittal balance, curve location, kyphosis, lordosis of each patient were also recorded to analyze their correlations with IBC. Correlation analyses were performed to identify the classified variables influencing IBC. The principal component analysis was used to extract common factors of radiographic parameters to eliminate interaction effects. The linear regression equation was established using principal components, the variables influencing IBC were identified. Results A cohort of 44 patients with IS (36 girls and 8 boys) were included in the present study. The mean IBC was 49.87% (range, 3%–100%). IBC of lumbar IS was negatively correlated with apical rotate factor (ARF, B = –0.385), mainly consisted of pelvic coronal plane rotation (PCPR, 0.449), Cobb angle (CA, 0.575), apical vertebral rotation (AVR, 0.918), and pelvic rotate factor (PRF, B = –0.387), mainly consisted of PT (0.861), PI (0.728), PCPR (–0.570). The regression equation of lumbar IS had statistical significance (F = 6.500, P = 0.005, R2 = 0.317), whereas statistically significance was not found in the regression equation of thoracic IS (F = 2.913, P = 0.106). The remaining parameters were not related to IBC. Conclusions For lumbar IS, ARF and PRF have negative effects on IBC, coronal and sagittal rotation of the pelvis is related to IBC.

Background Advancements in medicine and the popularity of lumbar fusion surgery have made lumbar adjacent segment disease (ASDz) increasingly common, but there is no mature plan for guiding its surgical treatment. Therefore, in this study, four different finite element (FE) ASDz models were designed and their biomechanical characteristics were analysed to provide a theoretical basis for clinical workers to choose the most appropriate revision scheme for ASDz. Methods According to whether internal fixation was retained, different FE models were created to simulate ASDz revision surgery, and flexion, extension, axial rotation and lateral bending were simulated by loading. The biomechanical characteristics of the adjacent segments of the intervertebral disc and the internal fixation system and the range of motion (ROM) of the lumbar vertebrae were analysed. Results The difference in the ROM of the fixed segment between FE models that did or did not retain the original internal fixation was less than 0.1°, and the difference was not significant. However, the stress of the screw–rod system when the original internal fixation was retained and prolonged fixation was performed with dual-trajectory screws was less than that when the original internal fixation was removed and prolonged fixation was performed with a long bar. Especially in axial rotation, the difference between models A and B is the largest, and the difference in peak stress reached 30 MPa. However, for the ASDz revision surgery segment, the endplate stress between the two models was the lowest, and the intradiscal pressure (IDP) of the adjacent segment was not significantly different between different models. Conclusion Although ASDz revision surgery by retaining the original internal fixation and prolonging fixation with dual-trajectory screws led to an increase in stress in the fusion segment endplate, it provides stability similar to ASDz revision surgery by removing the original internal fixation and prolonging fixation with a long bar and does not lead to a significant change in the IDP of the adjacent segment while avoiding a greater risk of rod fracture.

Objective To explore the kinematic biomechanical changes and symmetry in the left and right sides of the facet joints of lumbar spine segments under different functional loads. Methods Participants (n = 10) performing standing flexion and extension movements were scanned using computed tomography (CT) and dual fluoroscopy imagine system. Instantaneous images of the L3–S1 vertebrae were captured, and by matching a three‐dimensional CT model with contours from dual fluoroscopy images, in vivo facet joint movements were reproduced and analyzed. Translations and rotations of lumbar vertebral (L3 and L4) facet joints of data were compared for different loads (0, 5, 10 kg). The participants performed flexion and extension movements in different weight‐bearing states, the translations and angles changes were calculated respectively. Results From standing to extension, there were no statistical differences in rotation angles for the facet joint processes of different vertebral segment levels under different weight loads (P > 0.05). Mediolateral axis and cranio‐caudal translations under different weight loads were not statistically different for vertebral segment levels (P > 0.05). Anteroposterior translations for L3 (1.4 ± 0.1 mm) were greater than those for L4 (1.0 ± 0.1 mm) under the different load conditions (P = 0.04). Bilaterally, mediolateral, anteroposterior, and cranio‐caudal translations of the facet joints under different weights (0, 10 kg) for each segment level (L3 and L4) were symmetric (P > 0.05). From flexion to standing, there were no statistical differences in rotation angles for different weights (0, 5, 10 kg) for each level (L3 and L4) (P > 0.05). There were no statistical differences between mediolateral, anteroposterior, and cranio‐caudal translations at each segment level (L3 and L4) under different loads (P > 0.05). Under the condition of no weight (0 kg), L3 mediolateral translations on the left side (1.7 ± 1.6 mm) were significantly greater (P = 0.03) than those on the right side (1.6 ± 1.6 mm). Left side (1.0 ± 0.7 mm) L4 mediolateral translations were significantly smaller (P = 0.03) than those on the right side (1.1 ± 0.7 mm). There were no statistical differences between different weights for either anteroposterior and cranio‐caudal translations (P > 0.05). There were no statistical differences for mediolateral, anteroposterior, and cranio‐caudal translations for 10 kg (P > 0.05). Conclusion Lumbar spine facet joint kinematics did not change significantly with increased loads. Anteroposterior translations for L3 were greater than those for L4 of the vertebral segments are related to the coronal facet joint surface. Changes in facet surface symmetry indicates that the biomechanical pattern between facet joints may change.

Background Regarding the repair of vertebral compression fractures, there is a lack of adequate biomechanical verification as to whether only half of the vertebral body and the upper and lower intervertebral discs affect spinal biomechanics; there also remains debate as to the appropriate length of fixation. Methods A model of old vertebral compression fractures with kyphosis was established based on CT data. Vertebral column resection (VCR) and posterior unilateral vertebral resection and reconstruction (PUVCR) were performed at T12; long- and short-segment fixation methods were applied, and we analyzed biomechanical changes after surgery. Results Range of motion (ROM) decreased in all fixed models, with lumbar VCR decreasing the most and short posterior unilateral vertebral resection and reconstruction (SPUVCR) decreasing the least; in the long posterior unilateral vertebral resection and reconstruction (LPUVCR) model, the internal fixation system produced the maximum VMS stress of 213.25 mPa in a lateral bending motion and minimum stress of 40.22 mPa in a lateral bending motion in the SVCR. Conclusion There was little difference in thoracolumbar ROM between PUVCR and VCR models, while thoracolumbar ROM was smaller in long-segment fixation than in short-segment fixation. In all models, the VMS was most significant at the screw-rod junction and greatest at the ribcage–vertebral body interface, partly explaining the high probability of internal fixation failure and prosthesis migration in these two positions.

The coastal Sanshandao mine is threatened by the overlying Quaternary water and seawater. Following an introduction to the geology and hydrogeological conditions in the mine area, a detailed hydrogeological survey and sampling were conducted and hydrochemical and stable isotopic (δ2H and δ18O) tests on various waters were carried out to characterize the origin of water in the mine tunnels. Investigation and statistical analysis indicated that the northwest-trending fractures with large dip angles and long trace lengths are well developed in the northeast compared with those in the southwest of the mine. The permeability coefficients of the rock masses are in the range 4.19×10(-8)-2.25×10(-5) m/s, indicating that the fractured rock masses have generally low permeability. The seepage water had higher values of EC, total dissolved solids, and concentrations of most elements than the seawater and saline groundwater. Besides, the isotope composition of the waters indicated that the seepage water was more isotopically enriched than seawater but less than brine. The proportions of the three different sources were calculated based on hydrochemical and isotopic analyses. Overall, the mine water was composed of 72% seawater, 14.8% brine, and 13.2% atmospheric precipitation, respectively. Therefore, some preventive measures are essential to avoid the probability of seawater inrush.