Optimization of in-brace corrective force in adolescents with Lenke type 5 curve using finite element model.

BACKGROUND: Pelvic parameters have been taken into consideration for the evaluation of the outcomes of bracing in AIS. To discuss the stress required to correct the pelvic deformity related to Lenke5 adolescent idiopathic scoliosis (AIS) by finite element analysis, and provide a reference for the shaping of the pelvic region of the brace. METHODS: An three-dimensional (3D) corrective force on the pelvic area was defined. Computed tomography images were used to reconstruct a 3D model of Lenke5 AIS. Computer-aided engineering software Abaqus was used to implement finite element analysis. By adjusting the magnitude and position of corrective forces, coronal pelvic coronal plane rotation (PCPR) and Cobb angle (CA) of lumbar curve in the coronal plane, horizontal pelvic axial plane rotation, and apical vertebra rotation (AVR) were minimized to achieve the best effect on the spine and pelvic deformity correction. The proposed corrective conditions were divided into three groups: (1) forces applied on X-axis; (2) forces applied both in the X- and Y-axis; and (3) forces applied along the X-, Y-, and Z-axis at the same time. RESULTS: In three groups, CA correction reduced by 31.5%, 42.5%, and 59.8%, and the PCPR changed to 12°, 13°, and 1° from 6.5°, respectively. The best groups of correction forces should simultaneously locate on the sagittal, transverse, and coronal planes of the pelvis. CONCLUSIONS: For Lenke5 AIS, 3D correction forces can sufficiently reduce scoliosis and pelvic asymmetrical state. Force applied along the Z-axis is vital to correct the pelvic coronal pelvic tilt associated with Lenke5 AIS.

Neutrophil-lymphocyte ratio as a risk factor for osteoporotic vertebrae fractures and femoral neck fractures.

Fracture is associated with osteopenia after osteoporosis. Neutrophil-lymphocyte ratio (NLR) is common in inflammatory diseases. NLR can be used as an effective clinical tool to assess postmenopausal osteoporosis. The aim of this study is to further explore the relationship between elevated NLR and the severity of osteoporotic vertebrae fractures and femoral neck fracture based on magnetic resonance imaging (MRI). A total of 80 patients with osteoporotic vertebrae fractures, osteoporotic femoral neck fracture in Baoding Second Central Hospital from 2017 to 2020 were selected as the research objects. This study included a series of pretreatment factors, mainly including white blood cell count, red blood cell count, hemoglobin, and the general condition of the patients. Statistical methods included Pearson chi-square test, Spearman correlation test, logistic regression analysis and receiver operator characteristic (ROC) curve. According to Pearson chi-square test, Spearman correlation test, univariate/multivariate logistic regression analysis, the severity of osteoporotic vertebrae fractures, osteoporotic femoral neck fracture was significantly correlated with NLR (P < .001). NLR (odds ratio [OR] = 13.229, 95% CI: 4.167-41.998, P < .001) was a significant independent risk factor for osteoporotic vertebrae fractures, osteoporotic femoral neck fracture. receiver operator characteristic (ROC) curve was used to detect the specificity and sensitivity. The level of NLR has an important influence on the severity of osteoporotic vertebrae fractures and femoral neck fracture. The higher the level of NLR, the more serious the osteoporotic vertebrae fractures and femoral neck fracture.

Freehand Regional Techniques for Subaxial Cervical Pedicle Screw Placement.

BACKGROUND: Although various subaxial cervical pedicle screw implantation techniques have been proposed, clinical operators have been unable to exactly determine the entry points and trajectory . The objective of this article is to propose freehand regional techniques (FRT) for subaxial cervical pedicle screw placements and to investigate the clinical effectiveness of FRT. METHODS: A total of 80 consecutive patients who underwent open subaxial cervical pedicle screw fixation using FRT from January 2015 to December 2020 were retrospectively reviewed, and preoperative cervical computed tomography (CT) images were used to observe the entry point and screw trajectory. The horizontal and vertical lines at the center of the cervical lateral mass was marked, and the entry point was chosen at the outer upper quadrant of the lateral mass. Both sagittal and axial trajectories were determined by CT images, generally perpendicular to the cervical laminae. Screw implantation accuracy was assessed using postoperative CT. RESULTS: After virtually inserting pedicle screws by FRT on preoperative cervical CT images, all of the entry points were located in the outer upper quadrant of the lateral mass and the trajectory perpendicular to the cervical laminae was just parallel to the pedicle's axis. A total of 694 pedicle screws were placed by FRT clinically, with a 96% accuracy rate. CONCLUSIONS: Pedicle screw implantation by FRT for subaxial cervical spine can be performed with acceptable safety and accuracy.

Application of dual-trajectory screws in revision surgery for lumbar adjacent segment disease: a finite element study.

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.

Effects of bracing on pelvic parameters in adolescent idiopathic scoliosis: A retrospective study.

To evaluate the effects of Chêneau bracing on Cobb's angle (CA) and spinopelvic parameters in adolescent idiopathic scoliosis (AIS) patients. In this retrospective study, we evaluated 51 AIS patients who received Chêneau bracing treatment between January 2020 and August 2021. The prebracing and in-bracing radiographs were analyzed about the spinopelvic parameters. The CA, pelvic coronal obliquity angle, thoracolumbar kyphosis (TLK), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), sagittal vertical angle, and coronal vertical angle were measured. Paired t-test was used to compare prebracing and in-bracing spinopelvic parameters. The Pearson correlation analysis was used to identify the relationships between the variations in the spinopelvic parameters. The mean age at the initiation of bracing was 13.6 ± 1.5 years. The mean prebracing CA was 24.0° ± 6.3°. There were no statistically significant differences between prebracing and in-bracing measurements of sagittal and coronal vertical angles. However, there were statistically significant differences between the prebracing and in-bracing measurements of the CA, pelvic coronal obliquity angle, TLK, LL, PT, and SS. A significant correlation was observed between PT and thoracolumbar kyphosis variations in the sagittal plane. The pelvic coronal obliquity angle variation was correlated to the prebracing pelvic coronal obliquity angle in the coronal plane. Chêneau's bracing effects of AIS can be extended to the pelvis. Affected by the Chêneau brace, the pelvis should be retro-rotated correspondingly to TLK hyperkyphosis on the sagittal plane, whereas in the coronal plane, pelvic obliquity was improved independently. The effect of Chêneau braces on the pelvic parameters should be fully considered before bracing treatment.

3D kinematic characteristics of lumbar facet joints in sitting position.

BACKGROUND: Recognizing the kinematic characteristics of lumbar facet joints is important for the prevention and treatment of lumbar degenerative diseases. Previous studies have been conducted in either the supine or standing position, and there are no measurements regarding the kinematic characteristics of the lumbar facet joints while sitting. The aim of this study was to measure and analyze lumbar facet joint motion characteristics while sitting. METHODS: Ten subjects (5 males and 5 females) performed the movements of flexion-extension, left bending-right bending, and left rotation-right rotation in a sitting position. Dual Fluoroscopic Image System and computed tomography technique were used to measure the displacement and rotation angle of the lumbar facet joints of the subjects for analysis. The movement characteristics of L3-S1 were measured. RESULTS: When the subjects were in sitting position, the lumbar vertebra mainly changed in Z-axis and α, ß angle when they performed flexion-extension activities. The displacement of the left facet joint was 4.65 ± 1.99 mm at L3-4, 1.89 ± 2.99 mm at L4-5, and 0.80 ± 2.27 mm at L5-S1 in the Z-axis, and the displacement of the right facet joint was 3.20 ± 2.61 mm at L3-4, 1.71 ± 3.00 mm at L4-5, and 0.31 ± 1.69 mm at L5-S1 in the Z-axis. The rotation in the α angle was 6.00 ± 4.49° at L3-4, 3.51 ± 5.24° at L4-5, and 0.97 ± 4.13° at L5-S1, which was significant different. The rotation in the ß angle was 2.30 ± 2.94°at L3-4, 0.16 ± 2.06° at L4-5, and 0.35 ± 1.74°at L5-S1, which was significant different. When the lumbar spine performed the activity of left bending-right bending, there were changes in rotation mainly in the Z-axis and ß angle. The displacement of left facet joint in the Z-axis was 1.34 ± 2.84 mm at L3-4, 2.11 ± 0.88 mm at L4-5, and 0.72 ± 0.81 mm at L5-S1; the rotation in the ß angle was 5.66 ± 2.70°at L3-4, 7.89 ± 2.59° at L4-5, and 1.28 ± 2.07° at L5-S1; when the lumbar spine performed the activity of left rotation-right rotation, there were changes in the ß angle. The rotation of ß angle was 4.09 ± 2.86° at L3-4, 2.14 ± 3.38° at L4-5, and 0.63 ± 1.85° at L5-S1. CONCLUSION: The lumbar facet joint motion in sitting position is different in each mode of motion. The horizontal displacement and rotation are predominant during flexion and extension activities, while there are different rotation in bending and rotation. The study shows the coupled motion of the lumbar facet joints while sitting, providing a new perspective on the kinematics of the lumbar spine and the etiology of lumbar degenerative diseases.

Network meta-analysis of short-term effects of different strategies in the conservative treatment of AIS.

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.

Evaluation of the efficiency of corticosteroids in treating adult with sepsis: A protocol for systematic review and meta-analysis.

BACKGROUND: Sepsis is a worldwide health problem that is a leading cause of mortality due to infection. Sepsis is prevalent in infections that are complicated with organ failure. Generally, sepsis is intricate and impaired corticosteroid metabolism leads to complex outcomes. Therefore, the provision of corticosteroids could lead to improved clinical outcomes. The effect of corticosteroids therapy in adult patients with sepsis is not well studied. Therefore, this study is an attempt to evaluate the efficacy of corticosteroids for treating adult cases of sepsis. METHODS: We will systematically search the randomized controlled trials for potential eligible studies from online databases, which includes 5 English databases (PubMed, EMBASE, Web of Science, PsycINFO, and Cochrane Library) and 4 Chinese databases (China National Knowledge Infrastructure, WanFang Database, VIP information database, and China Biomedical Database) from their origin to March 2021. Languages were restricted to English and Chinese. Two independent authors will be screening the literature, collect, and perform data extraction and quality assessment. Data will be synthesized using appropriate statistical methods. RESULTS: This study will summarize present evidence to evaluate the efficacy of corticosteroids for the treatment of adult cases of sepsis. CONCLUSION: The results of the present study will provide the latest, reliable, superior quality evidence for the clinical application of corticosteroids for treating sepsis patients. ETHICS AND DISSEMINATION: The present study will use published data and does not require ethics approval. PROTOCOL REGISTRATION NUMBER: March 28, 2021.osf.io/tm6sw. (https://osf.io/tm6sw/).

Kinematic Characteristics and Biomechanical Changes of Lower Lumbar Facet Joints Under Different Loads.

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.

Biomechanical finite element analysis of vertebral column resection and posterior unilateral vertebral resection and reconstruction osteotomy.

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.

Pelvic rotation parameters related to in-brace correction in patients with idiopathic scoliosis.

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.

Multiple cardiac arrests induced by pulmonary embolism in a traumatically injured patient: A case report and review of the literature.

RATIONALE: Pulmonary embolism-induced cardiac arrest should not be given up arbitrarily, knowing that the etiology of pulmonary embolism is reversible in most cases. PATIENT CONCERNS: We present a case of continuous resuscitation lasting approximately 4 hours, during which 21 episodes of cardiac arrest occurred in a 46-year-old man who sustained high-level paraplegia after a road traffic accident. DIAGNOSES: Multiple cardiac arrests induced by pulmonary embolism. INTERVENTIONS: The patient received cardiopulmonary resuscitation and thrombolytic therapy. OUTCOMES: The patient was discharged in 2 weeks when his condition turned for the better. LESSONS: Cardiopulmonary resuscitation of patients with pulmonary embolism-induced cardiac arrest should not be given up arbitrarily, knowing that the etiology of pulmonary embolism is reversible in most cases. Effective external cardiac compression can not only save the patient's life but also attenuate neurological sequelae. Thrombolytic therapy is the key to the final success of resuscitation.

Investigating the permeability of fractured rock masses and the origin of water in a mine tunnel in Shandong Province, China.

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.

Phycocyanin may suppress D-galactose-induced human lens epithelial cell apoptosis through mitochondrial and unfolded protein response pathways.

Apoptosis of lens epithelial cell (LEC) plays an important role in cataract formation, and its prevention may be one of the therapeutic strategies in treating cataract. This study used human lens epithelial cell (hLEC) line SRA01/04 to investigate the protective effect and mechanism of phycocyanin on glactose-induced apoptosis in hLEC. hLECs were cultured in D/F(12)-10% FBS medium containing 125mM d-galactose with or without phycocyanin. Cell viability was assessed by methylthiazol tetrazolium (MTT) assay. Cell apoptosis was elevated with Wright-Giemsa staining, AO/EB double staining, and DNA fragmentation assay. Mitochondrial apoptosis-associated molecules and unfolded protein response-associated molecules from cultured SRA01/04 cells were quantified using protein blot analysis. The results demonstrated that phycocyanin suppressed SRA01/04 cells' morphologic changes and apoptosis induced by d-galactose, inhibited the expression and activation of caspase 3, alternated the Bax/Bcl-2 ratio, and down-regulated the level of p53, GRP78, and CHOP in d-galactose-treated SRA01/04 cells. These results suggest that phycocyanin might suppress d-galactose-induced hLEC apoptosis through two pathways: mitochondrial pathway, involving p53 and Bcl-2 family protein expression, and unfolded protein response pathway, involving GRP78 and CHOP expression.