BACKGROUND:Lumbar degenerative disease is a disease of the musculoskeletal system that primarily affects the intervertebral structures,and the disease is treated with lumbar fusion and disc replacement.OBJECTIVE:To conduct comparative analysis of the differences between lumbar fusion,mechanical lumbar disc prosthesis replacement,and viscoelastic lumbar disc prosthesis replacement.METHODS:The computerized tomography images of a healthy adult were used to construct a finite element model of the L2-L5 normal lumbar spine with Mimic,Geomagic,and Ansys software.The equipment required for lumbar fusion and lumbar spine replacement was constructed using modeling software,and the L3-L4 segment of the lumbar spine was processed according to the surgical requirements for lumbar fusion and intervertebral disc replacement,creating the corresponding finite element model.Specific boundary conditions were applied to extract the mobility of each lumbar spine segment,the stresses on the neighboring intervertebral discs,and the stresses on the prosthesis lining.RESULTS AND CONCLUSION:(1)Compared with the preoperative period,the maximum stress in the upper neighboring discs increased by 64.09％and 39.79％in the forward flexion and lateral bending states if the original mobility was maintained after lumbar fusion surgery.The maximum stress in the lower neighboring discs increased by 24.39％and 20.98％in forward flexion and lateral bending.This suggested that the upper adjacent discs would suffer greater stress changes than the lower adjacent discs during heavy physical labor.(2)Disc replacement did not show significant changes in adjacent disc stress,with mechanical prosthesis replacement slightly reducing adjacent disc stress,while viscoelastic prosthesis replacement was more in line with the biological properties of the disc,with maximum adjacent disc stress similar to that of the preoperative period.(3)In terms of stability,the mechanical prosthesis replacement segment showed a 51.67％increase in range of motion in the lateral bending state and a 53.27％increase in range of motion in the posterior extension state,whereas the viscoelastic prosthesis was better able to maintain mobility in the replacement segment.(4)In addition,the stresses in the liner of the mechanical prosthesis were mainly concentrated in the edge region,and this stress distribution may lead to edge wear and thus affect the service life of the prosthesis.

BACKGROUND:Arthroscopic anchor repair has become the main treatment method for rotator cuff tears at present.Among them,the insertion status of the anchor is a key factor in the success or failure of the operation.However,currently,the impact of the insertion depth of the anchor on the stress of the bone tunnel and the anchor under different bone density conditions remains unclear.OBJECTIVE:To explore the stress distribution of the bone tunnel and the anchor when the insertion depth of the anchor varies under different bone density conditions by using three-dimensional finite element analysis technology.METHODS:The CT image data of the humerus of volunteers were collected,and the models of the humerus and the anchor were constructed by using Mimics,3-Matic,and Solidworks software.In 3-Matic,holes with distances of 0,2,4,6,and 8 mm from the surface of the humerus were respectively created at the same position of the humerus and assembled with the anchor.In Mimics,values were assigned based on the CT gray value to obtain a model with normal bone mass(T value ≥-1.0).The parameters were changed to construct models with reduced bone mass(-2.5＜T value＜-1.0)and osteoporosis(T value＜-2.5).In each model,a 70 N pulling force was applied to the anchor along the direction tangent to the inner edge of the bone tunnel.The stress distribution and magnitude of the bone tunnel and the anchor when inserted at different depths under different bone density conditions were observed.RESULTS AND CONCLUSION:(1)When the insertion depth was the same,as the bone density decreased,the maximum equivalent stress of the anchor increased,while the maximum equivalent stress of the bone tunnel decreased.(2)When the bone density was the same,as the insertion depth of the anchor increased,the maximum equivalent stress of the anchor decreased.When the insertion depth was 4 mm,the stress of the bone tunnel was the smallest and the distribution was relatively uniform.The stress of the anchor was mainly distributed around the lower anchor hole and the proximal thread,and the stress of the bone tunnel was mainly at the part in contact with the proximal thread.The increase in the insertion depth would change the uniformity and pattern of the stress distribution,while the bone density had a relatively small impact on the stress distribution pattern.(3)It is concluded that the bone density of the humerus is crucial for the anchor repair of rotator cuff tears.It is recommended that clinicians measure the bone density of the greater tuberosity of the humerus before the operation.Excessive insertion depth of the anchor does not significantly increase its stability.Clinicians can conduct personalized preoperative assessments by using the finite element analysis method in combination with the actual situation of patients to achieve the best surgical results.

BACKGROUND:Upper lumbar spinal stenosis is a multifactorial degenerative disorder of the spine.For narrowing of the spinal canal in the upper lumbar region(L1-L4),surgical decision-making is particularly complex.Existing minimally invasive surgeries each have their own advantages and limitations.Currently,there are few reports on biomechanical comparison and finite element analysis of different surgical methods for the treatment of high lumbar spinal stenosis.OBJECTIVE:To analyze the biomechanical impact of endoscopic unilateral laminotomy for bilateral decompression,transforaminal endoscopic lumbar decompression,and cross-overtop decompression in the treatment of upper lumbar spinal stenosis using endoscopy,and to verify the reliability and effectiveness of these three surgical techniques in treating upper lumbar spinal stenosis,providing a biomechanical basis for clinical decision-making.METHODS:The CT images of the lumbar spine of a healthy volunteer were selected,and the finite element model M0 of the normal lumbar L1-L5 segments was established using Mimics,Geomagic,Solid works,and Ansys software.The L2-L3 segment,representing upper lumbar characteristics,was chosen.Based on this model,the surgical models for endoscopic unilateral laminotomy for bilateral decompression(M1),transforaminal endoscopic lumbar decompression(M2),and cross-overtop decompression(M3)were established.Using software,the changes in the range of motion of the entire lumbar segment and the maximum Von Mises stress of the intervertebral discs were simulated and evaluated for each group of models under six loading conditions:flexion,extension,left lateral bending,right lateral bending,left rotation,and right rotation.RESULTS AND CONCLUSION:(1)Compared with model MO,the range of motion in M1,M2,and M3 increased under all six conditions,with M1 showing a greater increase.(2)M1 and M2 demonstrated significant increases in range of motion under forward bending,extension,and right rotation,while the increase under other conditions remained below 7％.(3)Compared with model M3,model M1 exhibited slightly increased overall joint range of motion during extension and left bending,while no significant changes were observed in other aspects,and the L1-L5 lumbar segments did not reach an unstable state.(4)In model M1,the maximum Von Mises stress of the intervertebral discs increased most significantly under flexion and extension loading conditions.However,under left lateral bending,right lateral bending,left rotation,and right rotation loading conditions,the increase did not exceed 5％.(5)These findings suggest that due to the sagittal anatomical characteristics of the facet joints,the unilateral laminotomy for bilateral decompression technique,while decompressing,involves resection of more facet joints,which impacts overall segmental stability.The transforaminal endoscopic lumbar decompression technique is suitable for patients with foraminal stenosis but cannot achieve complete decompression for those with severe ventral central stenosis.The Cross-Overtop technique effectively enlarges the volume of the central canal and lateral recess,optimizing decompression,and shows unique advantages in treating upper lumbar spinal stenosis.

BACKGROUND:Steroid-induced osteonecrosis of the femoral head(SANFH)is a severe orthopedic disease characterized by interruption of the blood supply to the femoral head and necrosis of subchondral bone,leading to joint dysfunction.Long-term use of glucocorticoids is the main cause of SANFH,and its pathogenesis involves multiple factors,including intravascular coagulation and osteocyte apoptosis.Vascular endothelial growth factor A(VEGF-A),as a key angiogenic factor,has potential value in the treatment of SANFH.OBJECTIVE:To summarize the mechanisms of action of VEGF-A in SANFH,including its progress in promoting angiogenesis,anti-apoptosis,and lipid metabolism regulation,and to discuss the prospects for clinical application of VEGF-A targeted therapy.METHODS:Literature related to VEGF-A targeted regulation of angiogenesis in the treatment of SANFH was identified through searches of PubMed,Web of Science,CNKI,and WanFang databases from database inception to November 2024.After quality assessment,71 articles were selected,data were extracted by independent researchers,and disagreements were resolved through group discussions.RESULTS AND CONCLUSION:(1)VEGF-A binds to its receptors VEGFR-1 and VEGFR-2,activating downstream signaling pathways that promote the proliferation,migration,and angiogenesis of endothelial cells.Therefore,it can promote the formation of collateral circulation and improve blood supply to the area of bone necrosis.(2)Reduced expression of VEGF-A may lead to a decrease in the number of blood vessels within bone tissue,exacerbating the ischemic state of the femoral head.Furthermore,VEGF-A has anti-apoptotic effects and reduce apoptosis in osteocytes and bone marrow cells,thus protecting bone tissue.(3)The role of VEGF-A in regulating lipid metabolism and inflammatory responses,as well as promoting the osteogenic differentiation of bone marrow mesenchymal stem cells,provides a new perspective for the treatment of SANFH.(4)The development of VEGF-A protein delivery systems,such as lipid nanoparticles and exosome-based delivery systems,offers new possibilities for the clinical application of VEGF-A.(5)The research progress of VEGF-A in SANFH treatment has laid a solid foundation for the development of new treatment strategies and has opened up new avenues for future research directions and clinical applications.(6)With further clarification of the mechanisms of action of VEGF-A and continuous advancements in delivery technologies,more effective treatments will be provided for SANFH patients,improving their prognosis.

OBJECTIVE:Postoperative recurrence is a common complication of percutaneous endoscopic lumbar discectomy for lumbar disc herniation,which can significantly increase the risk of reoperation.A well-performing risk prediction model can help identify high-risk groups early and prevent postoperative recurrence.This study systematically evaluated the risk prediction model for postoperative recurrence after percutaneous endoscopic lumbar discectomy to provide a reference for surgical decision-making.METHODS:The PubMed,Embase,Web of Science,CNKI,WanFang Data,VIP,and CBM were electronically searched to collect studies on the recurrence risk prediction models after percutaneous endoscopic lumbar discectomy from inception to July 1,2024.Two reviewers independently screened the literature and extracted data.The models' risk of bias,applicability,and report quality were assessed using prediction model risk of bias assessment tool(PROBAST)and Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis(TRIPOD)tools,respectively.Meta-analysis of postoperative recurrence rate of percutaneous endoscopic lumbar discectomy and related predictors was performed using Revman 5.4 software.RESULTS:(1)A total of 15 studies were included,all of which were retrospective studies,including 24 models for predicting the risk of recurrence after percutaneous endoscopic lumbar discectomy.(2)The PROBAST evaluation results indicated that all 15 studies exhibited a high risk of bias.Regarding applicability,two studies demonstrated a low risk,while 13 presented a high risk.(3)Regarding the TRIPOD reporting quality,the overall quality across the 15 studies was low.The primary reasons for this low compliance included the failure to report blinding,a lack of explanation for the sample size calculation method,lack of detailed description of missing data processing methods,and lack of information such as introduction to the model used.(4)Furthermore,the area under the receiver operating characteristic curve for the model ranged from 0.684 to 0.972,with the number of potential predictor variables varying from 15 to 28.(5)The results of meta-analysis showed that the postoperative recurrence rate of lumbar disc herniation patients treated with percutaneous endoscopic lumbar discectomy was 12％(95％CI=9.0％-15.0％),Modic changes(OR=6.72,95％CI=3.90-11.59),body mass index(OR=1.28,95％CI=1.10-1.49),work intensity(OR=3.22,95％CI=1.85-5.59),age(OR=2.28,95％CI=1.50-3.48),and smoking history(OR=2.65,95％CI=1.75-4.00)were independent influencing factors for postoperative recurrence of percutaneous endoscopic lumbar discectomy(all P＜0.05).CONCLUSION:The overall predictive performance of the recurrence risk prediction models after percutaneous endoscopic lumbar discectomy is satisfactory;however,the model exhibits a high overall risk of bias and applicability,coupled with low reporting quality.Additionally,there is a lack of prospective research and external validation.Future,risk prediction models should consider factors such as Modic changes,body mass index,work intensity,age,and smoking history as potential predictors.

BACKGROUND:In China,the patient population with osteonecrosis is large,and there is an urgent need to find new preventive targets to develop more effective treatment strategies.Metabolomics studies have shown that there is an association between human metabolites and osteonecrosis,but the causal relationship between blood metabolites and osteonecrosis has not yet been clarified.OBJECTIVE:To investigate the causal relationship between blood metabolites and osteonecrosis through two-sample Mendelian randomization analysis.METHODS:The public data of 486 blood metabolites(exposure factors)and osteonecrosis(outcome factors)were collected.Data of 486 blood metabolites were derived from a genome-wide association estimate for blood metabolites published in Nature Genetics in 2014,which covered 7 824 European adults.The single nucleotide polymorphism data for osteonecrosis were obtained from the FinnGen public database R11 dataset,containing information on a total of 431 614 samples and 21 306 430 single nucleotide polymorphism loci,with 1 788 cases of osteonecrosis and 429 826 controls,with all participants being of European descent.Mendelian randomization analysis(inverse variance weighting method,MR-Egger method,and weighted median method)was performed by Rstudio software,and then the heterogeneity test,horizontal pleiotropy test and Steiger directionality test were performed to ensure the robustness and reliability of the results.RESULTS AND CONCLUSION:(1)Sixteen blood metabolites were identified as having a significant causal relationship with osteonecrosis(Pinverse variance weighting＜Pfalse discovery rate＜0.05).(2)Eight blood metabolites increased the risk of osteonecrosis(including four known metabolites and four unknown metabolites),specifically pantothenate,beta-hydroxyisovalerate,hippurate,salicyluric glucuronide,X-08766,X-11452,X-12776 and X-14662.(3)Eight blood metabolites could reduce the risk of osteonecrosis(six known metabolites and two unknown metabolites),including cortisol,1-palmitoylglycerol(1-monopalmitin),pyroglutamyl glycine,2-stearoylglycerophosphocholine,p-cresol sulfate,ergothioneine,X-06307,X-12092.(4)The above results suggest that there is a causal relationship between 16 blood metabolites and osteonecrosis,which is expected to be a potential target for intervention in the occurrence and treatment of osteonecrosis in the future.(5)Despite the lack of relevant data from large-scale Asian populations at present,this study provides important reference value for the field of osteonecrosis in China based on European population data.In the future,domestic medical workers may be able to achieve precise intervention for osteonecrosis by regulating metabolite levels.In addition,based on the results of this study,relevant researchers can further explore the mechanism of action of metabolites in the treatment of osteonecrosis with traditional Chinese medicine,which not only helps to deepen the understanding of traditional Chinese medical therapies but also promotes the progress of integrated traditional Chinese and Western medicine research,driving the development of personalized treatment plans that are more suitable for the characteristics of the Chinese population.

BACKGROUND:The stress effect of autophagy on epithelial cells,fibroblasts and myofibroblasts is closely related to the formation process of pulmonary fibrosis.OBJECTIVE:To screen the genes related to autophagy in patients with pulmonary fibrosis,and explore their correlation with the prognosis of patients with pulmonary fibrosis,in order to provide a new target for clinical intervention in pulmonary fibrosis.METHODS:The gene expression profiling dataset downloaded from GSE70866 was used as a training set,differentially expressed genes between pulmonary fibrosis patients and normal healthy individuals was analyzed using the R language and intersected with autophagy-related genes to identify the differentially expressed genes with the most significant changes.Multiple analysis methods were used to identify key prognostic genes and construct genetic prognostic models.Patients with pulmonary fibrosis were divided into high-risk and low-risk groups according to their risk scores,and the validity of the prognostic model was verified using the Siena cohort and Leuven cohort validation sets.A cell model of pulmonary fibrosis was established by inducing HFL-1 cells(human embryonic lung fibroblasts)with transforming growth factor-β1,and an animal model of pulmonary fibrosis was established in mice by tracheal instillation of bleomycin to validate the expressions of prognostic genes.RESULTS AND CONCLUSION:(1)There were 2 650 differentially expressed genes between fibrotic tissue and normal tissue.Among them,34 genes related to autophagy showed significant expression changes.(2)Kaplan-Meier survival analysis curves for the Siena cohort and Leuven cohort validation sets showed significantly lower survival in the high-risk group than in the low-risk group.(3)Three autophagy genes related to prognosis were screened out:myelocytomatosis viral oncogene(MYC),C-C motif chemokine ligand 2(CCL2),and GABA type a receptor associated protein like 1(GABARAPL1).(4)Both in vivo and in vitro studies showed that compared with the control group,the expression levels of myelocytomatosis viral oncogene and C-C motif chemokine ligand 2 mRNA and protein were significantly higher in the lung fibrosis model group(P＜0.01,P＜0.05),while the expression levels of GABA type a receptor associated protein like 1 mRNA and protein were lower(P＜0.001).To conclude,bioinformatics methods are used to analyze the expression of three autophagy-related genes in pulmonary fibrosis and their correlation with the prognosis of patients with pulmonary fibrosis.The constructed prognostic model has good predictive ability for the 1-,2-,and 3-year survival rates of patients with pulmonary fibrosis.Moreover,in vivo and in vitro models have been used to verify that myelocytomatosis viral oncogene and C-C motif chemokine ligand 2 are highly expressed in lung fibroblasts and tissues,and that GABA type a receptor associated protein like 1 is lowly expressed.

BACKGROUND:Autophagy,as a key regulatory mechanism of cell development,plays an important role in different stages of embryonic development.The mechanism of how autophagy regulates embryonic development through histone modifications is currently unclear.OBJECTIVE:To investigate the effect of autophagy on trimethylation of lysine 4 on histone H3(H3K4me3)modification in embryos and its effect on embryonic development.METHODS:Mouse fertilized eggs were divided into control and autophagy inhibitor-treated groups(chloroquine phosphate-treated group and 3-methyladenine-treated group),and cultured in vitro to different periods of time,and were then classified as early 2-cell embryos,middle 2-cell embryos,late 2-cell embryos,4-cell embryos,8-cell embryos,morula stage,and blastocyst stage.Levels of reactive oxygen species,autophagy marker proteins LC3B and P62,DNA loss marker γH2AX,and H3K4me3 were analyzed by immunofluorescence assay in late 2-cell embryos of each group.Changes in H3K4me3 modification in late 2-cell embryos of each group were detected by CUT&Tag.RESULTS AND CONCLUSION:(1)Autophagy inhibition caused embryo development arrest.(2)There was no significant difference in reactive oxygen species and γH2AX between the autophagy inhibitor-treated groups and control group.(3)H3K4me3 levels were significantly elevated in the autophagy inhibitor-treated group compared with the control group.(4)CUT&Tag results showed a significantly increased H3K4me3 peaks on the proximal promoter region of the genes after autophagy inhibition and an increase of H3K4me3-specific modification genes.These findings suggest that autophagy may affect embryonic development by regulating the level of H3K4me3 modification.

BACKGROUND:Obesity is not only related to metabolic diseases such as diabetes and cardiovascular disease,but also closely related to the increased risk of cognitive decline,dementia and other neurodegenerative diseases.Studies have found that aerobic exercise and resistance exercise can help improve obesity-related cognitive impairment,but their therapeutic effects and related mechanisms of action are still unclear.OBJECTIVE:To explore the protective effects of aerobic and resistance exercises on the nervous center of obesity-related cognitive impairment mice.METHODS:Forty-eight 8-week-old C57BL/6J wild-type male mice were randomly divided into four groups:a control group was fed normally for 20 weeks;a high fat group was fed with high fat diet(60％fat energy)for 20 weeks;an aerobic exercise group was fed with 12 weeks of high-fat diet followed by 8 weeks of aerobic exercise;and a resistance exercise group was fed with 12 weeks of high-fat diet followed by 8 weeks of resistance exercise.After the exercise intervention,body mass was weighed,insulin tolerance and glucose tolerance were tested to evaluate insulin resistance,and cognitive function of mice in each group was detected by new object recognition experiment and Y-maze experiment.The morphology of hippocampal and cortical tissue cells was observed by hematoxylin-eosin staining.The mRNA relative expression levels of tumor necrosis factor-α and interleukin-6 were detected by real-time fluorescence quantitative PCR,and the protein expressions of Bax,Bcl-2,nuclear factor-κB,Cleaved Caspase-1,Caspase-3,synapsin 1 and brain-derived neurotrophic factor were detected by western blot.RESULTS AND CONCLUSION:(1)Compared with the control group,the body mass of mice increased in the high-fat group(P＜0.05),accompanied by insulin resistance and cognitive dysfunction,the expression levels of nuclear factor-κB,Bax,Caspase-3,Cleaved Caspase-1 in the hippocampus were significantly increased(P＜0.05),the expression levels of brain-derived neurotrophic factor,synapsin 1and Bcl-2 proteins were significantly decreased(P＜0.05),Bcl-2/Bax ratio was significantly decreased(P＜0.05),and the mRNA levels of inflammatory cytokines,tumor necrosis factor-α and interleukin-6,were significantly up-regulated(P＜0.05).(2)Compared with the high-fat group,the above indexes were significantly improved in the aerobic exercise group(P＜0.05),while in the resistance exercise group,the body mass of mice was significantly decreased,the levels of inflammatory cytokines tumor necrosis factor-α and interleukin-6 mRNA were significantly decreased(P＜0.05),the protein expression of Caspase-3 was significantly decreased(P＜0.05),and the protein expression of brain-derived neurotrophic factor was significantly up-regulated(P＜0.05),but no significant changes were observed in the other indexes(P＞0.05).In conclusion,long-term exercise can reduce insulin resistance,down-regulate the expression of nuclear factor-κB pathway,weaken inflammatory response,inhibit neuronal apoptosis and improve synaptic plasticity,resulting in neuroprotective effects,and effectively alleviate obesity-related cognitive dysfunction in obese mice.The therapeutic effect of aerobic exercise is superior to that of resistance exercise.

BACKGROUND:The pathogenesis of steroid-induced osteonecrosis of the femoral head is complex,involving vascular endothelial injury,osteocyte apoptosis,inflammatory responses,and bone metabolism disorders.MicroRNAs(miRNAs),as key regulators of gene expression,play an important role in steroid-induced osteonecrosis of the femoral head.OBJECTIVE:To comprehensively analyze the regulatory role of miRNAs in steroid-induced osteonecrosis of the femoral head and to evaluate their potential as biomarkers and therapeutic tools.METHODS:Relevant literature was retrieved from PubMed,Web of Science,CNKI,and WanFang databases using specific keywords,and articles were selected based on the inclusion and exclusion criteria.By reading titles,abstracts,or full texts,articles with poor relevance or repetitive content were excluded,and 76 articles were finally included for analysis.RESULTS AND CONCLUSION:miRNAs regulate gene expression by binding to the 3'untranslated region of target mRNAs,affecting cell differentiation,proliferation,apoptosis,and stress responses.Specific miRNAs such as miR-33-5p,miR-99a,miR-106b-5p,miR-155,miR-146a,and miR-21 play a central regulatory role in vascular injury,inflammatory responses,osteocyte differentiation,and apoptosis in steroid-induced osteonecrosis of the femoral head.Additionally,the expression patterns of miRNAs are closely related to the pathogenesis of steroid-induced osteonecrosis of the femoral head,showing potential as biomarkers.Although miRNAs shows great potential as biomarkers in therapeutic strategies,the current limitation of sample size and lack of multi-population validation restrict the universality and reliability of the results.Moreover,the efficacy and safety of miRNA therapeutic strategies(including off-target effects and delivery issues)remain major challenges in realizing clinical applications.