ObjectiveTo explore the effects of Jingui Shenqiwan （JSW） and Liuwei Dihuangwan （LDW） on the reproductive ability and brain function of normal mice and compare the actions of the two medications. MethodsSeven groups of female and male mice were divided at a ratio of 2∶1. Except for the control group， the other six groups were as follows： a group of both males and females receiving JSW （3.0 g·kg^-1）， a group of both males and females receiving LDW （4.5 g·kg^-1）， a group of males receiving water and females receiving JSW， a group of males receiving water while females receiving LDW， a group of females receiving water while males receiving JSW， and a group of females receiving water while males receiving LDW. Each group was administered the drug for 14 days and then caged together at a 2∶1 （female∶male） ratio to detect the number of pregnant mice and calculate the pregnancy rate. Pregnant mice continued receiving the drug until they naturally gave birth， which was followed by the observation of newborn mice， calculation of their average number， and the measurement of the offspring's preference for sugar water and neonatal recognition index. At the end of the experiment， the weights of the thymus and spleen were measured to calculate the organ coefficients， and mRNA or protein expression was analyzed in the brain and testes or ovaries. A 1% sucrose solution was used to examine the euphoria of their brain reward systems， while novel object recognition test （NOR） was applied to assess their memory capabilities. mRNA expression was detected using real-time quantitative polymerase chain reaction （Real-time PCR） assay， and protein expression was analyzed with Western blot. ResultsCompared with the control group， oral administration of JSW to both male and female mice for 14 days significantly increased the pregnancy rate of female mice on day 2 after being caged together （P<0.05）， while LDW showed a trend but no statistical significance. Additionally， compared with the control group， JSW could upregulate the gene expression of gonadotropin-releasing hormone （GnRH） in the thalamus， as well as reproductive stem cell factor （SCF） and tyrosine kinase receptor （c-Kit） in the testes and reproductive stem cell marker mouse vasa homologue （MVH） in the ovaries， upregulate the expression of proteins influencing neuronal functional activity， such as brain-derived neurotrophic factor （BDNF）， in hippocampal neurons （P<0.05）， and enhance sucrose preference in male mice （P<0.05）. Compared with the control group， JSW significantly increased sucrose preference and novel object recognition index in offspring mice （P<0.05）， which was related to the upregulation of hippocampal dopamine D1 receptor （D1R） and N-methyl-D-aspartate receptor （Nmdar） gene expression. Compared with the control group， both JSW and LDW could upregulate the protein expression of glucocorticoid receptor （GR）， BDNF， and tyrosine kinase receptor B （TrkB） in the hippocampus of offspring mice （P<0.05）. ConclusionJSW significantly enhances the reproductive ability of normal mice， which is not only related to the release of gonadotropin but also associated with its regulation of brain function. Additionally， JSW has a certain regulatory effect on the brain function of the offspring mice.

ObjectiveTo systematically compare the differential regulation of the maternal-fetal interface cell lineages and communication networks in the CBA/J×DBA/2 mouse model of recurrent pregnancy loss （RPL） by the two classic therapeutic methods-tonifying the kidney to stabilize the fetus and invigorating the spleen to stabilize the fetus （Shoutai Wan， Juyuan Jian）-of traditional Chinese medicine （TCM） at the single-cell resolution and clarify their modern scientific connotations. MethodsFemale non-pregnant CBA/J mice were caged with male BALB/c （blank group） and DBA/2 （modeling group） mice separately. Pregnant mice in the modeling group were randomly grouped as follows： high/low-dose Shoutai Wan， high/low-dose Juyuan Jian， model （RPL）， and positive control （dydrogesterone）， with 10 mice in each group. Starting from the day after the detection of the vaginal plug， mice were administrated with drugs or an equal volume of normal saline by gavage for 10 consecutive days. After the intervention， the following indicators were measured. ① Macroscopic evaluation： general conditions， uterine wet weight， embryo loss rate， four coagulation parameters ［prothrombin time （PT）， activated partial thromboplastin time （APTT）， fibrinogen （FIB）， and thrombin time （TT）］， and peripheral blood estradiol （E₂） and progesterone （Pg） levels. The decidua with embryos was stained with hematoxylin-eosin （HE） and evaluated by transmission electron microscopy （TEM）. The expression of B-cell lymphoma-2 （Bcl-2）， vascular endothelial growth factor （VEGF）， angiotensin Ⅱ （AngⅡ）， matrix metalloproteinase-2 （MMP-2）， interleukin-6 （IL-6）， leukemia inhibitory factor （LIF）， CXC chemokine ligand 12 （CXCL12）， and microtubule-associated protein 1 light chain 3 homolog （LC3）Ⅰ/Ⅱ was quantified by Western blot. ② Mechanism analysis at the single-cell level： The decidua with embryos from the blank， model， high-dose Shoutai Wan， and high-dose Juyuan Jian groups （6 mice per group， with 3 single-cell samples per group， totaling 24 mice） were analyzed by the BD Rhapsody™ platform， and the whole-cell atlas was drawn by uniform manifold approximation and projection （UMAP） dimensionality reduction clustering combined with the single-cell mouse cell atlas （scMCA）. The differentially expressed genes （DEGs） and cell interaction networks were analyzed via Gene Ontology （GO）， Kyoto Encyclopedia of Genes and Genomes （KEGG）， and CellChat， and the protein-protein interaction （PPI） map of subtype cells was constructed. The CytoTRACE pseudo-temporal analysis was performed to explore the developmental trajectories of core immune cells （natural killer cells， NK cells） from maternal and fetal sources. Results① Pathological and Western blot results indicated that compared with the blank group， the RPL group showed an increase in the embryo loss rate （P<0.01）， down-regulated expression of Bcl-2， LIF， MMP-2， and Vegf in the decidua with embryos （P<0.05）， up-regulated protein levels of CXCL-12， AngⅡ， and IL-6 （P<0.05）， blocked angiogenesis， apoptosis-inflammation imbalance， and coagulation dysfunction. Both prescriptions dose-dependently reduced the abortion rate and restored the angiogenesis-inflammation balance， and Shoutai pill showed superior performance in restoring the E₂ level to the Pg level （P<0.05）. ② Single-cell transcriptome analysis indicated that compared with the blank group， the RPL group showed differences in multiple key cell populations such as decidual cells， trophoblast cells， endothelial cells， erythroblasts， NK cells， and macrophages at the maternal-fetal interface. Immunity and angiogenesis were the key links in RPL. Compared with the RPL group， high-dose Shoutai Wan reversed the changes of NK cells in the embryonic layer （upregulating the mRNA levels of 17 genes and downregulating the mRNA levels of 29 genes） and macrophages （upregulating the mRNA levels of 117 genes and downregulating the mRNA levels of 53 genes） through the regulation of gene expression. High-dose Shoutai pill regulated the immune cells to affect unfolded proteins， cell adhesion， and programmed cell death， thereby promoting decidualization and angiogenesis and modulating embryo-membrane development. High-dose Juyuan Jian regulated the key subgroups of NK cells （up-regulating the mRNA levels of 9 genes and down-regulating the mRNA levels of 17 genes） and macrophages （up-regulating the mRNA levels of 110 genes and down-regulating the mRNA levels of 81 genes）， which affected decidual inflammation and apoptosis and intervened in glycolysis. ③ The pseudo-temporal analysis and communication network indicated that the communication frequency of the RPL group decreased. High-dose Shoutai Wan restored maternal-fetal tolerance through pathways such as NKG2D， CDH5， GDF， and FASLG. High-dose Juyuan Jian enhanced the IL-6/LIFR/JAK/signal transducer and activator of transcription 3 （STAT3） and desmosome/SEMA6/tumor necrosis factor-like weak inducer of apoptosis （TWEAK） signaling to improve endometrial receptivity. The RPL group showed an increased proportion of toxic dNK7， a decreased proportion of reparative dNK4， and blocked embryo fNK1. High-dose Shoutai Wan down-regulated dNK7 and up-regulated dNK4. High-dose Juyuan Jian inhibited the terminal differentiation of dNK7 and up-regulated LILRB1， thus restoring the balance of cytotoxicity and repair. ConclusionBoth the kidney-tonifying and spleen-invigorating methods are effective in treating RPL. NK and macrophages are the key immune cells in the interaction between the embryo and the membrane. The kidney-tonifying method （Shoutai Wan） has an advantage in regulating the phenotypes of unfolded protein， cell adhesion， and programmed cell death， and shows expression characteristics closer to the physiological state in the regulation of NKG2D and CDH5 signals. The spleen-invigorating method （Juyuan Jian） has an advantage in regulating epithelial-mesenchymal transition （EMT）， angiogenesis， and glycolysis and shows higher communication intensity in the IL-6 and LIFR pathways.

ObjectiveTo elucidate the efficacy connotation of Shudi Qiangjin pills （SQP） against liver and kidney deficiency in steroid-induced osteonecrosis of femoral head （SONFH） from the perspective of the "disease-syndrome-formula" association and to clarify the underlying mechanisms based on in vivo and in vitro experiment validation. MethodsThe chemical components and the corresponding putative targets of SQP were collected from the Integrative Pharmacology-based Research Platform of Traditional Chinese Medicine （TCMIP） v2.0， the Encyclopedia of Traditional Chinese Medicine （ETCM） v2.0， and HERB databases. The SONFH-related genes were identified based on the differential expression profiles of peripheral blood of patients with SONFH compared to the healthy volunteers， and the disease phenotype-related targets were collected from the TCMIP v2.0 database. Then， the interaction network of "SONFH-related genes and candidate targets of SQP" was constructed based on "gene-gene interaction information"， and the major network targets were screened by calculating the topological characteristic values of the network followed by the functional mining according to the Kyoto Encyclopedia of Genes and Genomes （KEGG） database and the SoFDA database. After that， the SONFH rat model was prepared by lipopolysaccharide combined with methylprednisolone injection， and 2.5， 5， 7.5 g·kg^-1 SQP （once per day， equivalent to 1， 2， and 3 times the clinical equivalent dose， respectively） or 7.3×10^-3 g·kg^-1 of alendronate sodium （ALS， once per week， equivalent to the clinical equivalent dose） was given for 8 weeks. The effect characteristics of SQP and ALS in the treatment of SONFH were evaluated by micro-computed tomography scanning， hematoxylin and eosin staining， alkaline phosphatase （ALP） staining， immunohistochemical staining， enzyme-linked immunosorbent assay， and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling（TUNEL）staining， and a comparative efficacy analysis was conducted with ALS. In addition， SONFH cell models were prepared by dexamethasone stimulation of osteoblasts， and the intervention was carried out with the medicated serum of SQP at the aforementioned three doses. Cell counting kit-8， ALP staining， ALP activity assay， alizarin red staining， and flow cytometry were employed to investigate the regulatory effect of SQP on osteoblasts. The expression levels of osteogenesis-related proteins and key factors of the target signaling axis were detected by quantitative real-time polymerase chain reaction and Western blot. ResultsThe network analysis results demonstrated that the candidate targets of SQP primarily exerted their therapeutic effects through key signaling pathways， including phosphoinositide 3-kinase（PI3K）/protein kinase B（Akt）， lipid metabolism and atherosclerosis， prolactin， chemokines， and neurotrophic factors pathways. These pathways were significantly involved in critical biological processes such as muscle and bone metabolism and the regulation of the "neuro-endocrine-immune" network， thereby addressing both modern medical symptoms （e.g.， delayed skeletal maturation and recurrent fractures） and traditional Chinese medicine （TCM） symptoms （e.g.， fatigue， aversion to cold， cold limbs， and pain in the limbs and joints in patients with SONFH characterized by liver and kidney deficiency syndrome. Among these pathways， the PI3K/Akt signaling pathway exhibited the highest degree of enrichment. The in vivo experimental results demonstrated that starting from the 4^th week after modeling， the modeling group exhibited a significant reduction in body weight compared to the control group （P<0.05）. After six weeks of treatment， all dosage groups of SQP showed significantly higher body weights compared to the model group （P<0.01）. Compared with the normal group， the model group exhibited significant decreases in bone mineral density （BMD）， bone volume fraction （BV/TV）， trabecular number （Tb.N）， osteocalcin （OCN）， alkaline phosphatase （ALP） levels in femoral head tissue， and serum bone-specific alkaline phosphatase （BALP） （P<0.01）， along with significant increases in trabecular separation （Tb.Sp）， empty lacunae rate in tissue， and apoptosis rate （P<0.01）. In comparison to the model group， the SQP intervention groups showed significant improvements in BMD， BV/TV and Tb.N （P<0.01）， significant reductions in Tb.Sp， empty lacunae rate and apoptosis rate （P<0.05）， and significant increases in protein levels of OCN and ALP as well as BALP content （P<0.05）. The in vitro experimental results revealed that all dosage groups of SQP medicated serum showed no toxic effects on osteoblast. Compared with the normal group， the model group displayed significant suppression of osteoblast proliferation activity， ALP activity， and calcified nodule formation rate （P<0.01）， significant decreases in mRNA transcription levels of OCN and Runt-related transcription factor 2 （RUNX2） （P<0.01）， significant reductions in protein content of osteopontin （OPN）， typeⅠ collagen （ColⅠ）A1， B-cell lymphoma-2 （Bcl-2）， PI3K， and phosphorylated （p）-Akt （P<0.01）， and a significant increase in apoptosis rate （P<0.01）. Compared with the model group， the SQP medicated serum intervention groups exhibited significant increases in proliferation activity， ALP activity， calcified nodule formation rate， mRNA transcription levels of OCN and RUNX2， and protein content of OPN， ColⅠA1， Bcl-2， PI3K， and p-Akt （P<0.05）， along with a significant decrease in apoptosis rate （P<0.01）. ConclusionSQP can effectively reduce the disease severity of SONFH with liver and kidney deficiency syndrome and improve bone microstructure， with the therapeutic effects exhibiting a dose-dependent manner. The mechanism may be related to its regulation of key processes such as muscle and bone metabolism and the correction of imbalances in the "neuro-endocrine-immune" network， thereby promoting osteoblast differentiation and inhibiting osteoblast apoptosis. The PI3K/Akt signaling axis is likely one of the key pathways through which this formula exerts its effects.

Diabetes mellitus（DM） is a globally prevalent chronic metabolic disease， and its hyperglycemia can lead to a series of serious complications. Although current DM treatments are effective， they still have side effects and limitations. Therefore， discovering new drugs has become a key approach to improving DM management. As a traditional Chinese medicine， Dendrobii Caulis has garnered significant attention due to its rich phytochemical properties， which may offer a natural approach to mitigate the harmful effects of DM. Studies have demonstrated that Dendrobii Caulis can significantly reduce blood glucose levels in diabetic animal models and improve insulin resistance. Modern pharmacological studies have shown that the hypoglycemic effect of Dendrobii Caulis is primarily based on multiple mechanisms， including improving insulin sensitivity， inhibiting liver glycogen breakdown， promoting liver glycogen synthesis， and reducing oxidative stress. In addition， polysaccharides in Dendrobii Caulis have been found to increase the serum level of glucagon-like peptide-1 （GLP-1）， which promotes insulin secretion and inhibits glucagon release， thereby improving the symptoms of DM and its complications. Given its potential hypoglycemic effect， Dendrobii Caulis is expected to be developed as a new hypoglycemic agent or health food with promising prospects for treating DM and its complications. With further basic and clinical research， Dendrobii Caulis is expected to become an important adjunct in DM treatment.

AIM: To compare the preoperative ocular biometry between Pentacam AXL and IOL Master 700 in cataract patients.METHODS:Prospective study. A total of 150 patients(150 eyes)with cataracts who were treated in our hospital from May to December 2024 were selected. The IOL Master 700 and Pentacam AXL were preoperatively used to measure axial length(AL), corneal curvature(K1, K2 and Km), anterior chamber depth(ACD), and white-to-white(WTW). The difference and consistency of the results of the two instruments were compared.RESULTS: There was no significant difference between the two instruments in the AL, K1, K2, Km, ACD, and WTW(all P>0.05). The Spearman correlation analysis showed that the two instruments positively correlated with the AL, K1, K2, Km, ACD and WTW of the operated eye(all P<0.001). The Bland-Altman analysis showed that for the Pentacam AXL and IOL Master 700, there were 5/150(3.3%), 7/150(4.7%), 4/150(2.7%), 5/150(3.3%), and 0 points outside the 95%LoA for the AL, K1, K2, Km, ACD, and WTW of the examined eyes, respectively, with all of these values less than 5%, indicating good consistency.CONCLUSION:The AL, K1, K2, Km, ACD and WTW of Pentacam AXL and IOL Master 700 in cataract patients before cataract phacoemulsification combined with IOL implantation show no significant differences, and have good correlation and consistency. The two instruments can be used interchangeably.

BACKGROUND:Sarcopenia is an age-related systemic skeletal muscle disease,which is associated with a variety of adverse outcomes such as falls,functional decline,frailty,and death.Postmenopausal women are one of the high-risk groups for sarcopenia.OBJECTIVE:To develop a predictive model for assessing the risk of sarcopenia in Chinese postmenopausal women based on high-quality database.METHODS:Data for this study were derived from 2 370 postmenopausal women from the China Health and Retirement Longitudinal Study(CHARLS),and sarcopenia was assessed using the Asian Working Group on Sarcopenia 2019(AWGS2019)recommended metrics.The study cohort was randomized into a training set(70％)and a validation set(30％).Risk factors for sarcopenia in postmenopausal women were screened using the least absolute shrinkage and selection operator,ten-fold cross-validation,and logistic regression.Nomogram predicting the risk of sarcopenia in postmenopausal women was constructed based on the risk factors,and the model efficacy was evaluated by the receiver operating characteristic curve and area under the curve(AUC),calibration curve,and decision curve analysis.RESULTS AND CONCLUSION:The prevalence of sarcopenia in this study was 23.50％and age,place of residence,sleep quality,cognitive function,depression,and the number of chronic diseases were selected as predictors of sarcopenia in postmenopausal women.The nomogram model showed good discrimination between the training and validation sets,with an AUC value of 0.751(95％confidence interval=0.724-0.778,P＜0.001),a specificity of 72.2％,and a sensitivity of 63.2％in the training set,and an AUC value of 0.763(95％confidence interval=0.721-0.805,P＜0.001),with a specificity of 69.6％and a sensitivity of 70.8％.The calibration curve showed a relatively significant agreement between the nomogram model and the actual observations,and the decision curve analysis demonstrated broad and good clinical utility.To conclude,the nomogram to assess the risk of sarcopenia constructed based on age,place of residence,sleep quality,cognitive function,depression,and number of chronic diseases,provides an effective tool for identifying and eliminating risk factors for sarcopenia in Chinese postmenopausal women,and helps to reduce the incidence of sarcopenia.

BACKGROUND:Hippocampal injury caused by aortic coarctation has been poorly studied,and combined detection of tumor necrosis factor α,nuclear factor κB and ionized calcium binding adaptor molecule-1 expression in aortic dissection has not been reported.OBJECTIVE:To observe histomorphologic changes in the hippocampus of a mouse model of aortic dissection and investigate the expression and significance of tumor necrosis factor alpha,nuclear factor kappaB and ionized calcium binding adaptor molecule-1 in the hippocampus of aortic dissection mice.METHODS:Sixteen healthy 3-week-old male C57BL/6 mice were randomly divided into two groups:control group and aortic dissection group,with eight mice in each group.In the aortic dissection group,mice were given β-aminopropionitrile monofumarate as drinking water for 4 weeks,and the angiotensin Ⅱ microinfiltration pump was then implanted to establish an animal model of aortic dissection.Mice in the control group were given normal diet and water.After the model was established,the maximum diameter of the ascending aorta was measured,hematoxylin-eosin staining and EVG staining were performed to evaluate the model formation rate,and the levels of inflammatory factors tumor necrosis factor α and interleukin 6 in serum were detected by enzyme-linked immunosorbent assay.The hippocampus was dissected and stained with hematoxylin-eosin to observe the pathological changes of the hippocampus in brain sections.The protein expression of tumor necrosis factor α,nuclear factor κB and ionized calcium binding adaptor molecule-1 was detected by western blot analysis.RESULTS AND CONCLUSION:(1)Compared with the control group,the maximum diameter of the ascending aorta in the aortic dissection group was significantly enlarged.(2)Hematoxylin-eosin staining of the aorta showed obvious thickening of the middle aorta and destruction and disorder of the aortic wall structure in mice.Neurons in the CA1 and CA3 regions of mice were sparsely arranged,reduced in size,and showed pyknosis with deeply stained nuclei.(3)Serum levels of inflammatory factors tumor necrosis factor α and interleukin 6 were increased in the aortic dissection group compared with the control group(P＜0.01).(4)The expression levels of tumor necrosis factor α,nuclear factor κB,phosphorylated nuclear factor κB,and ionized calcium binding adaptor molecule-1 in the hippocampus were increased in the aortic dissection group compared with the control group(P＜0.05).To conclude,microglial activation and increased expression of tumor necrosis factor α and nuclear factor κB may be involved in hippocampal neuron injury in aortic dissection mice.

BACKGROUND:Mitochondrial dysfunction is a key mechanism underlying the pathogenesis and progression of diabetic cystopathy.Recent studies have suggested that drugs targeting mitochondrial metabolism,oxidative stress,and apoptosis pathways can inhibit bladder tissue degeneration,offering novel therapeutic directions for diabetic cystopathy.OBJECTIVE:To explore the association between mitochondrial abnormalities and diabetic cystopathy and to summarize the mechanisms of pharmacological interventions targeting mitochondrial function.METHODS:The key words are"mitochondria,diabetes,diabetic cystopathy,diabetic bladder dysfunction,detrusor,urothelium,neuron,peripheral nerves"in Chinese and English.Relevant literature was retrieved from CNKI,WanFang,PubMed,and Web of Science.Selected articles were systematically screened and analyzed.RESULTS AND CONCLUSION:During the progression of diabetic cystopathy,mitochondria in detrusor muscle,urothelium,and peripheral nerve cells exhibit alterations in characterization,activity,function,and behavior.Under diabetic conditions,mitochondrial damage leads to increased reactive oxygen species production,increased cytochrome C release,reduced Bcl-2/Bax ratio,enhanced nuclear translocation of apoptosis-inducing factors,and activation of the poly(ADP-ribose)polymerase/c-Jun N-terminal kinase/mitochondrial apoptosis pathway.Mitochondria also act as damage-associated molecular patterns to regulate NLRP3,triggering inflammatory responses.Disrupted mitochondrial energy metabolism involves AMP-activated protein kinase/peroxisome proliferator-activated receptor gamma coactivator-1α signaling axis-mediated phenotypic changes,decreased levels of respiratory chain complexes Ⅰ,Ⅱ,andⅣ,impaired oxidative phosphorylation,inhibited tricarboxylic acid cycle,and reduced mitochondrial spare respiratory capacity.Novel therapeutic agents or formulations can ameliorate diabetic cystopathy by alleviating oxidative stress,exerting anti-inflammatory effects,and modulating energy-sensing pathways to restore mitochondrial function.Although mitochondrial roles in other diabetic complications have been extensively studied,research on their involvement in diabetic cystopathy remains insufficient and warrants further exploration.

BACKGROUND:Abutment screw loosening is one of the most common mechanical complications in implant restoration.Mechanical wear,as a potential cause of thread loosening,warrants attention due to its impact on mechanical performance and long-term stability.However,studies on the mechanical effects of thread wear in abutment screws remain limited,and no definitive conclusions have been reached.OBJECTIVE:To investigate the effect of different degrees of mechanical wear on the spatial stress distribution of the Morse taper connection implant system,with a view to providing a theoretical basis for the clinical assessment of the long-term stability of dental implants.METHODS:Three-dimensional finite element models of Morse taper implants with central screw thread wear levels of 0,0.1,1,10,and 100 μm were established using SolidWorks software,and simulation analysis with Ansys Workbench software was performed.The implant models were inserted into artificial bone blocks(simulating type Ⅱ bone,with a cortical bone thickness of 2 mm on the outer layer and cancellous bone inside).An alternating load of 300 N in the buccolingual direction was applied at the centroid of the abutment(forming an angle of 30° with the long axis of the implant).The von Mises stress,principal stress,displacement,and fatigue life of the abutment,central screw,implant,and bone tissue in the five groups of models were analyzed.RESULTS AND CONCLUSION:(1)As the degree of mechanical wear on the central screw thread increased,the von Mises stress,principal stress,and strain in the implant and abutment also increased.The stress in the model was concentrated at the top of the implant,at the shoulder level of the implant,at the neck of the abutment,and at the bottom edge of the abutment.(2)Under moderate wear conditions(≥ 10 μm),the fatigue life of the implant system decreased by 30％,and the maximum von Mises stress of the central screw decreased by 37％,with the stress still primarily concentrated at the transition area between the head and the body of the central screw.(3)Under significant wear conditions(≥ 100 μm),the von Mises stress of the central screw decreased by 98％,with the stress concentrated at the screw head,and the fatigue life of the implant system decreased by 63％.Therefore,when the wear level of the central screw thread reaches ≥ 10 μm,the risk of screw loosening is significantly increased,and the fatigue life of the implant system is markedly reduced,warranting clinical attention.

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.