BACKGROUND:In 2019,the modified cortical bone trajectory technique was proposed by our team,significantly improving traditional methods.Previous studies have highlighted its superior biomechanical properties for segment fixation.However,a comprehensive systematic analysis of its specific biomechanical effects on adjacent segment degeneration is lacking,particularly regarding its influence on range of motion and intervertebral disc stress in posterior lumbar interbody fusion and transforaminal lumbar interbody fusion techniques.OBJECTIVE:To investigate the biomechanical effects of modified cortical bone trajectory screw techniques on adjacent segment degeneration in posterior lumbar interbody fusion and transforaminal lumbar interbody fusion.METHODS:CT scans were performed on three human cadaver specimens to establish and validate three-dimensional intact finite element models of the L1-S1 segment.For each of these,the posterior lumbar interbody fusion or transforaminal lumbar interbody fusion with three different fixation techniques was reconstructed at the L4-L5 segment.The L4-L5 segment was fixed using three different internal fixation techniques(modified cortical bone trajectory,cortical bone trajectory,and traditional pedicle screws).The range of motion and von Mises stress of the intervertebral disc of the L3-L4 and L5-S1 segments were recorded with a 400 N compressive load and 7.5 N moments in flexion,extension,left-right bending,and left-right rotation.The impacts of the three internal fixation techniques on adjacent segment degeneration in the two kinds of fusion were compared and analyzed.RESULTS AND CONCLUSION:(1)In the posterior lumbar interbody fusion model,the modified cortical bone trajectory screw group showed a reduced range of motion on adjacent segments(L3-L4,L5-S1)under six loading conditions compared to both the cortical bone trajectory screw group and traditional bone trajectory screw group.Specifically,the modified cortical bone trajectory screw group significantly reduced the maximum stress on the intervertebral disc in the superior adjacent segment(L3-L4)during extension compared to the traditional bone trajectory screw group(P=0.005),while the stress on the intervertebral disc in the inferior adjacent segment(L5-S1)exhibited greater dispersion.Similarly,the cortical bone trajectory screw group also significantly reduced the maximum stress on the intervertebral disc in the superior adjacent segment(L3-L4)during extension compared with the traditional bone trajectory screw group(P=0.03).(2)Compared with transforaminal lumbar interbody fusion,the three internal fixation techniques(modified cortical bone trajectory,cortical bone trajectory,and traditional pedicle screws)showed a trend of reduced range of motion in the inferior adjacent segment(L5-S1)under six loading conditions.In contrast,the maximum stress on the intervertebral discs in both the superior and inferior adjacent segments(L3-L4,L5-S1)exhibited an increasing trend in the posterior lumbar interbody fusion model.(3)It is concluded that in the posterior lumbar interbody fusion model,the modified cortical bone trajectory screw exhibited superior biomechanical properties in reducing the range of motion at adjacent segments,which may have a beneficial effect on reducing the risk of adjacent segment degeneration.

BACKGROUND:In 2019,the modified cortical bone trajectory technique was proposed by our team,significantly improving traditional methods.Previous studies have highlighted its superior biomechanical properties for segment fixation.However,a comprehensive systematic analysis of its specific biomechanical effects on adjacent segment degeneration is lacking,particularly regarding its influence on range of motion and intervertebral disc stress in posterior lumbar interbody fusion and transforaminal lumbar interbody fusion techniques.OBJECTIVE:To investigate the biomechanical effects of modified cortical bone trajectory screw techniques on adjacent segment degeneration in posterior lumbar interbody fusion and transforaminal lumbar interbody fusion.METHODS:CT scans were performed on three human cadaver specimens to establish and validate three-dimensional intact finite element models of the L1-S1 segment.For each of these,the posterior lumbar interbody fusion or transforaminal lumbar interbody fusion with three different fixation techniques was reconstructed at the L4-L5 segment.The L4-L5 segment was fixed using three different internal fixation techniques(modified cortical bone trajectory,cortical bone trajectory,and traditional pedicle screws).The range of motion and von Mises stress of the intervertebral disc of the L3-L4 and L5-S1 segments were recorded with a 400 N compressive load and 7.5 N moments in flexion,extension,left-right bending,and left-right rotation.The impacts of the three internal fixation techniques on adjacent segment degeneration in the two kinds of fusion were compared and analyzed.RESULTS AND CONCLUSION:(1)In the posterior lumbar interbody fusion model,the modified cortical bone trajectory screw group showed a reduced range of motion on adjacent segments(L3-L4,L5-S1)under six loading conditions compared to both the cortical bone trajectory screw group and traditional bone trajectory screw group.Specifically,the modified cortical bone trajectory screw group significantly reduced the maximum stress on the intervertebral disc in the superior adjacent segment(L3-L4)during extension compared to the traditional bone trajectory screw group(P=0.005),while the stress on the intervertebral disc in the inferior adjacent segment(L5-S1)exhibited greater dispersion.Similarly,the cortical bone trajectory screw group also significantly reduced the maximum stress on the intervertebral disc in the superior adjacent segment(L3-L4)during extension compared with the traditional bone trajectory screw group(P=0.03).(2)Compared with transforaminal lumbar interbody fusion,the three internal fixation techniques(modified cortical bone trajectory,cortical bone trajectory,and traditional pedicle screws)showed a trend of reduced range of motion in the inferior adjacent segment(L5-S1)under six loading conditions.In contrast,the maximum stress on the intervertebral discs in both the superior and inferior adjacent segments(L3-L4,L5-S1)exhibited an increasing trend in the posterior lumbar interbody fusion model.(3)It is concluded that in the posterior lumbar interbody fusion model,the modified cortical bone trajectory screw exhibited superior biomechanical properties in reducing the range of motion at adjacent segments,which may have a beneficial effect on reducing the risk of adjacent segment degeneration.

The frequent challenges encountered in spinal surgeries utilizing pedicle screws for osteoporotic patients include inadequate fixation strength and postoperative screw loosening or displacement, often requiring reinforcement or surgical revision. The bone cement-augmented technique, without altering the diameter, length, or material of the screws, can solidly enhance the stability of internal fixation and improve surgical efficacy. The bone cement types that are widely applied in clinical practice encompass Polymethyl Methacrylate (PMMA), Calcium Phosphate Cement (CPC), and their composite series.The bone cement reinforcement techniques are mainly divided into two categories: bone cement augmentation within pedicle screw pathway and hollow lateral-hole screw reinforcement. The technique of pedicle screw pathway bone cement augmentation significantly enhances the stability of internal fixation by pre-injecting bone cement into the pedicle screw pathway before inserting the screw. However, it poses potential risks such as difficulty in precisely controlling the distribution of bone cement and susceptibility to leakage. In comparison, hollow lateral-hole screw augmentation, through the optimization of bone cement injection techniques and screw design, not only augments screw stability but also effectively decreases the incidence of complications such as bone cement leakage, especially exhibiting outstanding performance in both primary and revision surgeries. For patients with severe osteoporosis or those requiring revision surgery due to compromised pedicle screw tracts, the bone cement-augmented cortical bone trajectory (CBT) exhibits favorable mechanical properties. By adjusting the screw placement pathway, it may potentially avoid the central venous sinus of the vertebra, thereby reducing the risk of bone cement leakage and embolism. However, further research is needed to confirm these findings. With the rapid development of robot-assisted pedicle screw placement technology, the precision and safety of spinal screws augmented with bone cement have been significantly enhanced, effectively minimizing surgical trauma and reducing the risk of complications. In the future, clinicians will make more scientific and objective selections of appropriate screw types and method of screw placement based on patients' bone quality, further reducing complications and adhering to the principle of personalized treatment. This will continuously enhance patient outcomes and prognosis, ultimately providing safer and more effective treatment options for patients.

Objective:To develop a deep learning model based on super-resolution endorectal ultrasound（ERUS）images for the preoperative prediction of perineural invasion（PNI）in patients with rectal cancer，thereby providing a reference for risk stratification and individualized treatment planning.Methods:A retrospective analysis was conducted on 382 patients with rectal cancer who underwent total mesorectal excision at Fujian Medical University Union Hospital between June 2019 and February 2024. Patients were randomly divided into a training set（ n=305）and a test set（ n=77）at a ratio of 8∶2，and further grouped into PNI-negative group and PNI-positive group subgroups based on pathological results. Super-resolution ultrasound images were generated from original ERUS images using a generative adversarial network（GAN）. Deep convolutional neural networks were developed based on features from intratumoral and peritumoral regions to identify the optimal region of interest（ROI）. The dSR5_ResNet18 and dSR5_ResNet50 models were constructed using the super-resolution images with a 5-pixel peritumoral extension. Representative clinical features were selected for subgroup analysis based on sample size and intergroup statistical differences between PNI-positive and PNI-negative patients. Forest plots were used to evaluate model applicability and robustness across subgroups. Results:The dSR5_ResNet18 model，built using super-resolution images of the tumor combined with a 5-pixel peritumoral region，achieved the best predictive performance，with an AUC of 0.867（95% CI=0.782 - 0.952）in the test set. Decision curve analysis demonstrated that the dSR5_ResNet18 model provided the greatest net clinical benefit. Forest plot analysis indicated strong generalizability of the models across subgroups such as pathological N stage，maximum lesion length，and lymph node enlargement，though relatively weaker performance was observed in the carcinoembryonic antigen（CEA）subgroup. Among all models，dSR5_ResNet18 exhibited the most consistent performance across subgroups，with the narrowest confidence intervals and highest robustness. Conclusions:The deep learning model incorporating ERUS-based super-resolution reconstruction demonstrated excellent performance in the preoperative prediction of PNI in rectal cancer. It offers significant advantages in image quality and generalizability，and may serve as a valuable tool to assist clinicians in formulating personalized treatment strategies.

Objective Exploring the clinical diagnosis and treatment status of epilepsy patients at the epilepsy specialty clinic in a single-center comprehensive hospital in the Lhasa area of the Tibetan Plateau.Methods Epilepsy patients who visited the epilepsy specialty clinic of the Department of Neurology at the Tibet Autonomous Region People's Hospital from September 2021 to June 2023 were continuously enrolled.Data such as clinical characteristics and diagnosis and treatment conditions of the enrolled patients was analyzed.Results A total of 121 patients were enrolled in this study,with 33.9%(41/121 cases)being new patients at our hospital and 6.6%(8/121 cases)being referred to our hospital.Non-adherence to treatment,with patients self-reducing or stopping medication without medical advice,accounted for 8.3%(10/121 cases)of the cases.The majority of epilepsy patients were in the young and middle-aged group,with 51.2%(62/121 cases)being between 18 and 44 years old.There were significant differences in the distribution of epilepsy patients across different age groups(P<0.001),while there was no significant difference in gender distribution(49.6%male vs.50.4%female,P>0.05).Generalized seizures were the predominant type of seizure(75.2%,91/121 cases),and 73.6%(89/121 cases)of the patients had an unknown etiology for their epilepsy,with symptomatic epilepsy accounting for 26.4%(32/121 cases)and structural causes being the most common at 24.8%(30/121 cases).Monotherapy was the main treatment for epilepsy(55.4%,67/121 cases),with sodium valproate being the most frequently prescribed drug for monotherapy at 22.3%(27/121 cases).Conclusion In the epilepsy specialty clinic in the plateau region,newly diagnosed patients account for about one-third,and over one-tenth of revisiting patients have not been receiving standardized treatment.The majority of our epilepsy patients are young to middle-aged adults.Generalized seizures are the predominant type.The etiology is unknown in the majority of cases,with structural causes being a common etiology in symptomatic epilepsy.Sodium valproate is the most frequently used antiseizure medication(ASM)in monotherapy in the plateau area.

Objective:To investigate the effect of DEAD-box helicase (DDX) 21 on myocardial ischemia-reperfusion (I/R) injury and its potential mechanisms.Methods:In vivo, adult male Bama pigs and C57BL/6J mice were used to establish a myocardial I/R injury model by ligating the left anterior descending coronary artery, with sham-operated groups set as controls. The expression of DDX21 in myocardium after I/R injury was assessed by quantitative real-time PCR (qRT-PCR), Western blot, and immunofluorescence staining. Following the establishment of the myocardial I/R injury model in mice, AAV9 vectors with cardiac-specific expression were injected in situ into the peri-infarct region (The I/R+DDX21 group, I/R+negative control (NC) group, I/R+sh-NC group and I/R+sh-DDX21 group were injected with AAV9:cTnT-DDX21, AAV9:cTnT-NC, AAV9:cTnT-sh-NC and AAV9:cTnT-sh-DDX21, respectively). Additionally, the I/R+A-485 group received intraperitoneal injections of the cAMP response element-binding protein (CREB) binding protein inhibitor A-485, while the I/R+PBS group was injected with an equivalent volume of phosphate-buffered saline (PBS) as the control. Echocardiography was performed on postoperative days 1 and 28 to evaluate cardiac function (left ventricular ejection fraction and fractional shortening). At 28 days post-surgery, mice were euthanized and heart tissues were harvested for histological sectioning. Myocardial fibrosis was evaluated using Masson′s trichrome staining. In vitro, primary cardiomyocytes were isolated from neonatal day 1 C57BL/6J mice using enzymatic digestion method. Cardiomyocytes were transfected with plasmids or small interfering RNA (siRNA). The cardiomyocytes transfected with DDX21-siRNA were assigned to the siDDX21 group, those transfected with the DDX21 plasmid were assigned to the DDX21 group, and those transfected with the corresponding empty plasmid or siRNA were assigned to the NC group. Additionally, cardiomyocytes were treated with A-485 (A-485 group) or PBS (PBS group). An oxygen-glucose deprivation/reoxygenation (OGD/R) model was used to simulate cellular injury. Transcriptome sequencing was performed to identify downstream mechanisms of DDX21. Differential gene expression analysis was conducted using software such as DESeq2, and alternative splicing events in the mRNA transcriptome were analyzed using rMATS software. Mitochondrial superoxide, mitochondrial membrane potential, ATP content, and mitochondrial respiratory chain complex enzyme activity in cardiomyocytes were detected using immunofluorescence staining and commercial assay kits. The oxidative phosphorylation level of the cells was assessed by the Seahorse extracellular flux analyzer. Acetylated DDX21 levels were measured using co-immunoprecipitation and Western blot assays.Results:The expression levels of DDX21 in myocardium from the Bama pigs and mice in the I/R injury model were significantly higher than those in the sham group (all P<0.001). Echocardiographic results showed that at 28 days post-surgery, compared to the I/R+NC group, the I/R+DDX21 group exhibited higher left ventricular ejection fraction and fractional shortening, while the I/R+sh-DDX21 group showed lower values; Masson staining results demonstrated that, compared to the I/R+NC group, the myocardial fibrosis area in the I/R+DDX21 group was significantly reduced, whereas it was significantly increased in the I/R+sh-DDX21 group (all P<0.001). Transcriptomic sequencing results suggested that DDX21 may influence myocardial injury by regulating mitochondrial metabolic activity. In vitro, compared to the OGD/R+NC group, the OGD/R+DDX21 group exhibited lower mitochondrial superoxide levels, higher polymer/monomer ratio, maximal oxygen consumption, reserve capacity, and ATP content. In contrast, the OGD/R+siDDX21 group showed the opposite results, with reduced activity of mitochondrial respiratory chain complex V (all P<0.05). Mechanistically, rMATS software and other analyses indicated that knockdown of DDX21 affected the alternative 3′ splicing sites of ATP5J precursor mRNA, inhibiting the splicing of certain exonic sequences. Overexpression of DDX21 upregulated both mRNA and protein levels of ATP5J. Co-immunoprecipitation experiments showed that, compared to the PBS group, acetylated DDX21 levels were reduced in the A-485 group. Further in vivo experiments showed that, compared to the I/R+PBS group, the I/R+A-485 group exhibited higher left ventricular ejection fraction and fractional shortening, and a lower proportion of left ventricular fibrosis (all P<0.001). Conclusions:DDX21 improves cardiomyocyte energy metabolism and alleviates I/R injury by regulating the alternative splicing of ATP5J. A-485 holds potential as a novel small molecule candidate for the treatment of myocardial injury.

Objective:To investigate the biological role and molecular mechanism of checkpoint kinase 1 (CHK1) in delaying cardiac aging in mice.Methods:In vitro, a senescence model of H9C2 cells (a cardiomyocyte line) was induced using H 2O 2. A control group (without H 2O 2 treatment) and three H 2O 2-treated groups (at concentrations of 10, 30, and 50 μmol/L) were set up. The CCK-8 assay was used to evaluate the proliferative activity of cells in each group; Western blot analysis was employed to detect the expression level of CHK1; and quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to determine the messenger RNA (mRNA) expression levels of P16 and interleukin-1β (IL-1β). In vivo, C57BL/6 wild-type mice aged 2 months ( n=15) and 24 months ( n=40), as well as myocardial-specific CHK1-overexpressing (CHK1-TG) mice aged 2 months ( n=15) and 24 months ( n=40), were selected. The mice were divided into four groups based on age and genotype: 2-month-old wild-type (WT-2M), 24-month-old wild-type (WT-24M), 2-month-old CHK1-TG (CHK1-TG-2M), and 24-month-old CHK1-TG (CHK1-TG-24M). Echocardiography was used to evaluate cardiac function of mice in the WT-24M and CHK1-TG-24M groups. Western blot analysis was conducted to measure the protein expression levels of CHK1, total Ras-related protein 1 (Rap1), NADPH oxidase 4 (Nox4), and Rap1-guanosine triphosphate (Rap1-GTP, the active form of Rap1) in the cardiac tissue of mice in each group. qRT-PCR was used to detect the messenger RNA (mRNA) expression levels of CHK1, collagen type Ⅰ (Coll1), matrix metalloproteinase-2 (Mmp2), alpha-smooth muscle actin (α-SMA), P53, P21, P16, thioredoxin 1 (Trx1), thioredoxin reductase (TrxR), glutathione recluctase (GR), Rap1, and Nox4. Immunofluorescence staining was employed to determine the protein expression levels of P53, P21, and P16, as well as the proportion of histone H2AX phosphorylation-positive cells. Dihydroethidium (DHE) staining was used to detect the relative intensity of DHE. Wheat germ agglutinin staining, HE staining, Masson staining and Sirius red staining were applied to measure the cross-sectional area of cardiomyocytes, cardiac morphology, and myocardial fibrosis area. Mice in the WT-24M and CHK1-TG-24M groups were intraperitoneally injected with the Rap1 activity inhibitor GGTI298 (25 μmol/kg). After injection, the oxidative stress damage in the cardiac tissue of the mice was detected, along with the mRNA expression levels of fibrosis-related indicators (Coll1, Mmp2, and α-SMA) and cell cycle inhibitory proteins (P16, P21, and P53). Results:A concentration of 30 μmol/L was determined as the optimal concentration for establishing an H 2O 2-induced senescence model of myocardial cells in vitro. The expression level of CHK1 in H9C2 cells of the 30 μmol/L H 2O 2 group was lower than that in the control group ( P<0.05). Echocardiographic examination showed that the left ventricular ejection fraction ((61.08±1.13)% vs. (52.55±2.02)%) and fractional shortening ((31.80±1.27)% vs. (25.18±1.59)%) of mice in the CHK1-TG-24M group were higher than those in the WT-24M group (both P<0.05). qRT-PCR and Western blot analysis revealed that, compared with the WT-24M group, mice in CHK1-TG-24M group had higher expression levels of CHK1 and its mRNA, lower expression levels of Nox4 and its mRNA, and higher expression level of Rap1-guanosine triphosphate (Rap1-GTP) (all P<0.05). However, there were no statistically significant differences in the total expression level of Rap1 and its mRNA between the two groups (both P>0.05). In addition, the mRNA expression levels of Coll1, Mmp2, and α-SMA in myocardial tissue of mice in the CHK1-TG-24M group were lower than those in the WT-24M group (all P<0.05). Immunofluorescence staining results showed that the expression levels of P53, P21, and P16 proteins, as well as the proportion of phosphorylated histone H2AX-positive cells in myocardial tissue of mice in the WT-24M group were higher than those in the CHK1-TG-24M group (all P<0.05). qRT-PCR further confirmed that the mRNA expression levels of the above-mentioned proteins in cardiac tissue of mice in the WT-24M group were higher than those in the CHK1-TG-24M group (all P<0.05). DHE staining results indicated that the relative intensity of DHE in cardiac tissue of mice in the CHK1-TG-24M group was lower than that in the WT-24M group ( P<0.05). Meanwhile, the left ventricular internal diameter, cross-sectional area of cardiomyocytes, and myocardial fibrosis area of mice in the CHK1-TG-24M group were all smaller than those in the WT-24M group (all P<0.05). Furthermore, the degree of DNA damage in cardiac tissue as well as the mRNA levels of fibrosis-related indicators (Coll1, Mmp2, and α-SMA) and cell cycle inhibitory proteins (P53, P21, P16) in mice of the WT-24M+GGTI298 group were higher than those in the WT-24M group and the CHK1-TG-24M+GGTI298 group (all P<0.05). Conclusion:CHK1 alleviates oxidative stress-induced damage in mouse cardiomyocytes by activating the Rap1/Nox4 signaling pathway, thereby delaying cardiac aging in mice.

The frequent challenges encountered in spinal surgeries utilizing pedicle screws for osteoporotic patients include inadequate fixation strength and postoperative screw loosening or displacement, often requiring reinforcement or surgical revision. The bone cement-augmented technique, without altering the diameter, length, or material of the screws, can solidly enhance the stability of internal fixation and improve surgical efficacy. The bone cement types that are widely applied in clinical practice encompass Polymethyl Methacrylate (PMMA), Calcium Phosphate Cement (CPC), and their composite series.The bone cement reinforcement techniques are mainly divided into two categories: bone cement augmentation within pedicle screw pathway and hollow lateral-hole screw reinforcement. The technique of pedicle screw pathway bone cement augmentation significantly enhances the stability of internal fixation by pre-injecting bone cement into the pedicle screw pathway before inserting the screw. However, it poses potential risks such as difficulty in precisely controlling the distribution of bone cement and susceptibility to leakage. In comparison, hollow lateral-hole screw augmentation, through the optimization of bone cement injection techniques and screw design, not only augments screw stability but also effectively decreases the incidence of complications such as bone cement leakage, especially exhibiting outstanding performance in both primary and revision surgeries. For patients with severe osteoporosis or those requiring revision surgery due to compromised pedicle screw tracts, the bone cement-augmented cortical bone trajectory (CBT) exhibits favorable mechanical properties. By adjusting the screw placement pathway, it may potentially avoid the central venous sinus of the vertebra, thereby reducing the risk of bone cement leakage and embolism. However, further research is needed to confirm these findings. With the rapid development of robot-assisted pedicle screw placement technology, the precision and safety of spinal screws augmented with bone cement have been significantly enhanced, effectively minimizing surgical trauma and reducing the risk of complications. In the future, clinicians will make more scientific and objective selections of appropriate screw types and method of screw placement based on patients' bone quality, further reducing complications and adhering to the principle of personalized treatment. This will continuously enhance patient outcomes and prognosis, ultimately providing safer and more effective treatment options for patients.

BACKGROUND:Osteoporotic trabecular structures are insufficient to maintain screw holding force,often leading to spinal fixation failure.Currently,the following four aspects are mainly used to solve this problem:(1)screw material;(2)surface coating treatment;(3)screw channel solidification strategy;(4)screw shape.The screw channel of the modified cortical bone trajectory screw placement technique has been proven to have a good fixation effect,but there is an urgent need to develop matching screws.OBJECTIVE:To compare the biomechanical performance differences of various types of spinal cortical bone thread screws in the modified cortical bone trajectory fixation of lumbar vertebrae using the finite element method.METHODS:The L4 vertebral models were constructed based on the CT data of three adult wet lumbar specimens(two males and one female)and subjected to finite element analysis.In the modified cortical bone trajectory fixation technique,fully cortical bone thread screws(single thread screws)with lengths of 45 mm and diameters of 5.5 mm and 4.5 mm were used and considered as groups A and B,which were compared with those of the traditional pedicle screw technique group(group C,6.0 mm diameter,45 mm length,double-threaded screw)and the cortical bone trajectory screw group(group D,4.5 mm diameter,45 mm length,double-threaded screw).Axial pull-out force,screw stability(determined by the displacement ratio of upper,lower,left,and right loads),and anti-spin-out torque were measured to compare fixation strength of each group of screws.RESULTS AND CONCLUSION:(1)Axial pull-out force:Group A＞group B(P=0.003),and both group A and group B were greater than the group C(P＜0.001,P=0.003)and group D(all P＜0.001).(2)Screw stability:When load was applied in the upward and downward directions on the screw,the load displacement ratio of the four screw double threads was greater in group A than in group B(P＞0.05);both group A and group B were greater than the group C(all P＜0.001)and the group D(all P＜0.001).(3)Anti-spin-out torque:Group A＞group B(P=0.008),and both group A and group B were greater than the group C(P=0.008,P=0.131).(4)It is indicated that during modified cortical bone trajectory fixation of lumbar vertebrae,the novel spinal cortical bone thread screw demonstrates superior biomechanical performance compared to double thread screws applied in the clinically classic pedicle screw trajectory and cortical bone trajectory.Additionally,the novel spinal cortical bone thread screw(D=5.5 mm,L=45 mm)becomes the optimal adaptation for the modified cortical bone trajectory screw path.

To investigate the detection status of human papillomavirus (HPV) among adult women in high-altitude regions of Xizang.