1.A single repetition time quantitative magnetic susceptibility imaging method for the lumbar spine using bipolar readout gradient.
Zhenxiang DONG ; Yihao GUO ; Qiang LIU ; Yizhe ZHANG ; Qianyi QIU ; Xiaodong ZHANG ; Yanqiu FENG
Journal of Southern Medical University 2025;45(6):1336-1342
OBJECTIVES:
To propose a single repetition time (TR) quantitative magnetic susceptibility imaging method for the lumbar spine using bipolar readout gradient, and compare the quantitative magnetic susceptibility measurement using single TR and dual TR methods for the lumbar spine with different bone densities.
METHODS:
A translation correction method was proposed to correct spatial misalignment along the frequency encoding direction between positive and negative gradient readout images, and the phase difference between the images was eliminated using a phase correction method. The data of lumbar vertebrae L1-L5 were collected using single TR and dual TR methods from 6 normal individuals, 2 patients with osteopenia, and 2 patients with osteoporosis. The magnetic susceptibility map was reconstructed, the quantitative results of single TR before and after correction were compared with those of the dual TR method.
RESULTS:
The linear regression result of the lumbar spine magnetic susceptibility values obtained by the single TR method before calibration and the dual TR method is Y=0.64*X-11.61. The linear regression result of the lumbar spine magnetic susceptibility values corrected by the single TR method and the dual TR method is Y=1.03*X+0.25. The results of the corrected single TR method were highly consistent with those of the dual TR method, and the calibrated single TR method could effectively distinguish osteopenia and osteoporosis patients from normal individuals.
CONCLUSIONS
The calibrated single TR bipolar readout gradient method can generate artifact-free lumbar spine quantitative magnetic susceptibility distribution maps and reduce data acquisition time by 50%.
Humans
;
Lumbar Vertebrae/pathology*
;
Magnetic Resonance Imaging/methods*
;
Female
;
Middle Aged
;
Male
;
Osteoporosis/diagnosis*
;
Adult
;
Bone Density
;
Aged
;
Bone Diseases, Metabolic/diagnosis*
2.Correlation between serum CA72-4 level and pathological differentiation degree of gastric cancer and its clinical significance
Xiao ZHANG ; Yizhe DIAO ; Tao DING ; Weilang XU ; Xiao QI ; Peiqiang CHEN ; Zhenyuan QIAN ; Zaiyuan YE
Journal of Chinese Physician 2025;27(10):1451-1454
Objective:To explore the correlation between serum carbohydrate antigen 72-4 (CA72-4) level and pathological differentiation degree of gastric cancer, and to provide reference for early diagnosis, prognosis evaluation and efficacy monitoring of gastric cancer.Methods:A retrospective study was conducted on 136 patients with gastric cancer admitted to Zhejiang Provincial People′s Hospital from April 2022 to December 2024. According to postoperative pathological diagnosis, patients were divided into well-differentiated group ( n=9), moderately differentiated group ( n=36) and poorly/undifferentiated group ( n=91). Preoperative CA72-4 levels and clinical characteristics of patients were collected to analyze the relationship between differentiation degree and CA72-4 level, and to compare the changes of CA72-4 before and after surgery in gastric cancer patients with different differentiation degrees. Results:The preoperative CA72-4 level in the poorly/undifferentiated group was significantly higher than that in the well-differentiated group and moderately differentiated group (all P<0.001). Preoperative CA72-4 level in gastric cancer patients was weakly negatively correlated with differentiation degree ( R=-0.341). After surgery, the CA72-4 level in the poorly/undifferentiated group decreased significantly compared with that before surgery ( P=0.043), while the changes in the well-differentiated group and moderately differentiated group were not significant. Conclusions:There are significant differences in CA72-4 levels among gastric cancer groups with different differentiation degrees. Preoperative CA72-4, as a tumor marker, is of great significance for early diagnosis, prognosis evaluation and postoperative monitoring of gastric cancer. Especially in patients with poorly/undifferentiated gastric cancer, the CA72-4 level is relatively high, which can be used for auxiliary diagnosis and formulation of treatment plans.
3.Expression of PTPRN in lung adenocarcinoma and its mechanism of promoting tumor metastasis
Lei WU ; Fenglin DU ; Mingna ZHAO ; Yizhe REN ; Xianzhou ZHANG ; Jiatao LOU
Journal of Shanghai Jiaotong University(Medical Science) 2025;45(7):846-857
Objective·To investigate the expression of protein tyrosine phosphatase receptor type N(PTPRN)in lung adenocarcinoma and its potential molecular mechanisms in promoting lung adenocarcinoma metastasis.Methods·A highly bone-metastatic A549-BM cell line was established through multiple rounds of intracardiac injection.RNA sequencing(RNA-seq),combined with Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analyses,was performed to identify PTPRN as a key metastasis-related gene.Subsequently,The Cancer Genome Atlas(TCGA)database was utilized to evaluate PTPRN expression in patients with lung adenocarcinoma and its correlation with clinical prognosis.Co-expression analysis based on TCGA data was conducted to identify and analyze key genes co-expressed with PTPRN.Small interfering RNA(siRNA)targeting PTPRN(siPTPRN)was transfected into A549-BM cells,and Transwell assays were performed to assess its effects on cell migration and invasion.Western blotting was used to detect the expression of epithelial-mesenchymal transition(EMT)-related proteins and the activation of the PI3K-AKT signaling pathway.siPTPRN-transfected A549-BM cells were injected into a mouse model via intracardiac injection,and in vivo metastasis was assessed.Additionally,multiple database analyses were integrated to predict BCL6 as an upstream transcription factor of PTPRN,and siBCL6 transfection experiments were performed to validate the regulatory effect of BCL6 on PTPRN expression.Results·RNA-seq and GO/KEGG enrichment analyses demonstrated that PTPRN was significantly upregulated in highly metastatic A549-BM cells and enriched in metastasis-associated pathways,including the PI3K-AKT signaling pathway and extracellular matrix(ECM)-receptor interactions.Analysis of the TCGA database further confirmed that PTPRN was highly expressed in lung adenocarcinoma patients and significantly associated with poor prognosis.Co-expression analysis based on TCGA data,combined with GO/KEGG enrichment analyses,revealed that PTPRN-associated genes were mainly enriched in biological processes such as neural signaling,endocrine regulation,cell communication,and ECM-receptor interactions.In vitro experiments demonstrated that siPTPRN transfection significantly inhibited the migration and invasion of A549-BM cells,accompanied by downregulation of EMT-related proteins and reduced activation of the PI3K-AKT signaling pathway.In vivo experiments further showed that PTPRN knockdown markedly suppressed the metastatic potential of A549-BM cells,confirming its pro-metastatic role.Additionally,siBCL6 transfection experiments demonstrated that BCL6 knockdown upregulated PTPRN expression.Conclusion·PTPRN is highly expressed in lung adenocarcinoma tissues and promotes tumor cell migration and metastasis by enhancing EMT and activating the PI3K-AKT signaling pathway.High PTPRN expression is significantly correlated with poor prognosis in lung adenocarcinoma patients,while PTPRN enhances lung adenocarcinoma cell invasiveness and metastatic potential.BCL6 may act as an upstream transcriptional regulator of PTPRN,influencing its expression levels.
4.Expression of PTPRN in lung adenocarcinoma and its mechanism of promoting tumor metastasis
Lei WU ; Fenglin DU ; Mingna ZHAO ; Yizhe REN ; Xianzhou ZHANG ; Jiatao LOU
Journal of Shanghai Jiaotong University(Medical Science) 2025;45(7):846-857
Objective·To investigate the expression of protein tyrosine phosphatase receptor type N(PTPRN)in lung adenocarcinoma and its potential molecular mechanisms in promoting lung adenocarcinoma metastasis.Methods·A highly bone-metastatic A549-BM cell line was established through multiple rounds of intracardiac injection.RNA sequencing(RNA-seq),combined with Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analyses,was performed to identify PTPRN as a key metastasis-related gene.Subsequently,The Cancer Genome Atlas(TCGA)database was utilized to evaluate PTPRN expression in patients with lung adenocarcinoma and its correlation with clinical prognosis.Co-expression analysis based on TCGA data was conducted to identify and analyze key genes co-expressed with PTPRN.Small interfering RNA(siRNA)targeting PTPRN(siPTPRN)was transfected into A549-BM cells,and Transwell assays were performed to assess its effects on cell migration and invasion.Western blotting was used to detect the expression of epithelial-mesenchymal transition(EMT)-related proteins and the activation of the PI3K-AKT signaling pathway.siPTPRN-transfected A549-BM cells were injected into a mouse model via intracardiac injection,and in vivo metastasis was assessed.Additionally,multiple database analyses were integrated to predict BCL6 as an upstream transcription factor of PTPRN,and siBCL6 transfection experiments were performed to validate the regulatory effect of BCL6 on PTPRN expression.Results·RNA-seq and GO/KEGG enrichment analyses demonstrated that PTPRN was significantly upregulated in highly metastatic A549-BM cells and enriched in metastasis-associated pathways,including the PI3K-AKT signaling pathway and extracellular matrix(ECM)-receptor interactions.Analysis of the TCGA database further confirmed that PTPRN was highly expressed in lung adenocarcinoma patients and significantly associated with poor prognosis.Co-expression analysis based on TCGA data,combined with GO/KEGG enrichment analyses,revealed that PTPRN-associated genes were mainly enriched in biological processes such as neural signaling,endocrine regulation,cell communication,and ECM-receptor interactions.In vitro experiments demonstrated that siPTPRN transfection significantly inhibited the migration and invasion of A549-BM cells,accompanied by downregulation of EMT-related proteins and reduced activation of the PI3K-AKT signaling pathway.In vivo experiments further showed that PTPRN knockdown markedly suppressed the metastatic potential of A549-BM cells,confirming its pro-metastatic role.Additionally,siBCL6 transfection experiments demonstrated that BCL6 knockdown upregulated PTPRN expression.Conclusion·PTPRN is highly expressed in lung adenocarcinoma tissues and promotes tumor cell migration and metastasis by enhancing EMT and activating the PI3K-AKT signaling pathway.High PTPRN expression is significantly correlated with poor prognosis in lung adenocarcinoma patients,while PTPRN enhances lung adenocarcinoma cell invasiveness and metastatic potential.BCL6 may act as an upstream transcriptional regulator of PTPRN,influencing its expression levels.
5.Effect of BML-284 Activating the Wnt/β-catenin Signaling Pathway on Aluminum-induced Ferroptosis in PC12 Cells
Yizhe YANG ; Jiafen ZHANG ; Ting ZHOU
Journal of Medical Research 2025;54(10):93-98
Objective To investigate the possible mechanism by which CID11210285hydrochloride(Wnt agonist 1,AMBMP,BML-284)regulates aluminum-induced neuronal ferroptosis through the Wnt/β-catenin pathway,providing a theoretical basis for fur-ther research on the mechanisms of aluminum-induced neuronal death.Methods Taking rat adrenal pheochromocytoma PC12 cells as the research object,determined exposure concentrations of Al(mal)3 and BML-284 via CCK-8 assay and divided into four groups:con-trol group,Al(mal)3group,BML-284group,and Al(mal)3+BML-284group.The contents of iron,glutathione(GSH),reactive oxy-gen species(ROS),and malondialdehyde(MDA)in PC12 cells were detected by using the kit.The protein expression of glutathione peroxidase 4(GPX4),solute carrier family 7member 11(SLC7A11),glycogen synthase kinase 3β(GSK3β),β-catenin,and tran-scription factor 4(TCF4)was analyzed by Western blot.The mRNA expression of GPX4 and SLC7A11 was determined by real-time flu-orescence quantitative polymerase chain reaction(RT-qPCR).Results Compared with the control group,the iron ion concentration in PC12 cells of the Al(mal)3group increased,while the expression of GPX4 protein decreased.Compared with the Al(mal)3group,the iron ion concentration in PC12 cells of the Al(mal)3+BML-284 group increased(P<0.05),and the expression of GPX4 protein and mR-NA increased(P<0.05).Conclusion BML-284 activates the Wnt/β-catenin pathway by promoting the stability and intranuclear accumulation of β-catenin and enhancing the formation of the β-catenin/TCF complex,in which TCF4 serves as a key transcription fac-tor,and the β-catenin/TCF4 complex directly binds to GPX4,which effectively alleviates the Al(mal)3-induced ferroptosis.
6.Mechanistic study of OGT-promoted non-small cell lung cancer proliferation via the ERK signaling pathway
Xianzhou ZHANG ; Fenglin DU ; Lei WU ; Yizhe REN ; Mingna ZHAO ; Jiatao LOU
Journal of Shanghai Jiaotong University(Medical Science) 2025;45(10):1288-1297
Objective·To investigate the expression level of O-GlcNAc transferase(OGT)in non-small cell lung cancer(NSCLC)and its impact on lung cancer proliferation,as well as to explore the underlying mechanisms.Methods·The expression of OGT in NSCLC tumors and adjacent normal tissues was detected by immunohistochemistry(IHC).The dataset(GSE31210)from the GEO database was analyzed to assess the correlation between OGT expression and NSCLC patient prognosis.siRNA transfection was performed to knock down OGT expression in H460 and H1299 cells,followed by total RNA extraction and transcriptome sequencing.Pathway enrichment analysis was conducted on differentially downregulated genes in the knockdown group compared with the control group,and Western blotting was used to validate the enrichment results.The effects of OGT knockdown on cell proliferation and colony formation in H460 and H1299 cells were evaluated using the cell counting kit-8(CCK-8)assay and colony formation assay,respectively.The impact of overexpressing downstream genes was also examined.Stable OGT-knockdown cell lines were generated using shRNA and subcutaneously inoculated into nude mice to monitor tumor growth.Results·IHC revealed that OGT expression was significantly upregulated in NSCLC tumor tissues compared to adjacent normal tissues.Patients with high OGT expression exhibited shorter survival times and poorer prognoses than those with low expression.Transcriptome sequencing demonstrated that genes downregulated after OGT knockdown were primarily enriched in the mitogen-activated protein kinase(MAPK)signaling pathway.Western blotting showed that total extracellular regulated protein kinase 1/2(ERK1/2)levels remained unchanged in H460 and H1299 cells after OGT knockdown,while phosphorylated ERK1/2(p-ERK1/2)and its downstream proto-oncogene JUNB protein were markedly reduced.Suppression of OGT expression attenuated the proliferation rate and colony formation capacity of H460 and H1299 cells,whereas JUNB overexpression rescued the proliferation defects induced by OGT knockdown.Notably,H460 cells with stable OGT knockdown formed significantly smaller tumors in nude mice.Conclusion·OGT is highly expressed in NSCLC and correlates with poor prognosis.Knockdown of OGT inhibits NSCLC cell proliferation and clonogenicity in vitro,and tumor growth in vivo.Mechanistically,OGT appears to promote NSCLC progression by activating the ERK/JUNB signaling axis.
7.Mechanistic study of OGT-promoted non-small cell lung cancer proliferation via the ERK signaling pathway
Xianzhou ZHANG ; Fenglin DU ; Lei WU ; Yizhe REN ; Mingna ZHAO ; Jiatao LOU
Journal of Shanghai Jiaotong University(Medical Science) 2025;45(10):1288-1297
Objective·To investigate the expression level of O-GlcNAc transferase(OGT)in non-small cell lung cancer(NSCLC)and its impact on lung cancer proliferation,as well as to explore the underlying mechanisms.Methods·The expression of OGT in NSCLC tumors and adjacent normal tissues was detected by immunohistochemistry(IHC).The dataset(GSE31210)from the GEO database was analyzed to assess the correlation between OGT expression and NSCLC patient prognosis.siRNA transfection was performed to knock down OGT expression in H460 and H1299 cells,followed by total RNA extraction and transcriptome sequencing.Pathway enrichment analysis was conducted on differentially downregulated genes in the knockdown group compared with the control group,and Western blotting was used to validate the enrichment results.The effects of OGT knockdown on cell proliferation and colony formation in H460 and H1299 cells were evaluated using the cell counting kit-8(CCK-8)assay and colony formation assay,respectively.The impact of overexpressing downstream genes was also examined.Stable OGT-knockdown cell lines were generated using shRNA and subcutaneously inoculated into nude mice to monitor tumor growth.Results·IHC revealed that OGT expression was significantly upregulated in NSCLC tumor tissues compared to adjacent normal tissues.Patients with high OGT expression exhibited shorter survival times and poorer prognoses than those with low expression.Transcriptome sequencing demonstrated that genes downregulated after OGT knockdown were primarily enriched in the mitogen-activated protein kinase(MAPK)signaling pathway.Western blotting showed that total extracellular regulated protein kinase 1/2(ERK1/2)levels remained unchanged in H460 and H1299 cells after OGT knockdown,while phosphorylated ERK1/2(p-ERK1/2)and its downstream proto-oncogene JUNB protein were markedly reduced.Suppression of OGT expression attenuated the proliferation rate and colony formation capacity of H460 and H1299 cells,whereas JUNB overexpression rescued the proliferation defects induced by OGT knockdown.Notably,H460 cells with stable OGT knockdown formed significantly smaller tumors in nude mice.Conclusion·OGT is highly expressed in NSCLC and correlates with poor prognosis.Knockdown of OGT inhibits NSCLC cell proliferation and clonogenicity in vitro,and tumor growth in vivo.Mechanistically,OGT appears to promote NSCLC progression by activating the ERK/JUNB signaling axis.
8.Effect of BML-284 Activating the Wnt/β-catenin Signaling Pathway on Aluminum-induced Ferroptosis in PC12 Cells
Yizhe YANG ; Jiafen ZHANG ; Ting ZHOU
Journal of Medical Research 2025;54(10):93-98
Objective To investigate the possible mechanism by which CID11210285hydrochloride(Wnt agonist 1,AMBMP,BML-284)regulates aluminum-induced neuronal ferroptosis through the Wnt/β-catenin pathway,providing a theoretical basis for fur-ther research on the mechanisms of aluminum-induced neuronal death.Methods Taking rat adrenal pheochromocytoma PC12 cells as the research object,determined exposure concentrations of Al(mal)3 and BML-284 via CCK-8 assay and divided into four groups:con-trol group,Al(mal)3group,BML-284group,and Al(mal)3+BML-284group.The contents of iron,glutathione(GSH),reactive oxy-gen species(ROS),and malondialdehyde(MDA)in PC12 cells were detected by using the kit.The protein expression of glutathione peroxidase 4(GPX4),solute carrier family 7member 11(SLC7A11),glycogen synthase kinase 3β(GSK3β),β-catenin,and tran-scription factor 4(TCF4)was analyzed by Western blot.The mRNA expression of GPX4 and SLC7A11 was determined by real-time flu-orescence quantitative polymerase chain reaction(RT-qPCR).Results Compared with the control group,the iron ion concentration in PC12 cells of the Al(mal)3group increased,while the expression of GPX4 protein decreased.Compared with the Al(mal)3group,the iron ion concentration in PC12 cells of the Al(mal)3+BML-284 group increased(P<0.05),and the expression of GPX4 protein and mR-NA increased(P<0.05).Conclusion BML-284 activates the Wnt/β-catenin pathway by promoting the stability and intranuclear accumulation of β-catenin and enhancing the formation of the β-catenin/TCF complex,in which TCF4 serves as a key transcription fac-tor,and the β-catenin/TCF4 complex directly binds to GPX4,which effectively alleviates the Al(mal)3-induced ferroptosis.
9.Correlation between serum CA72-4 level and pathological differentiation degree of gastric cancer and its clinical significance
Xiao ZHANG ; Yizhe DIAO ; Tao DING ; Weilang XU ; Xiao QI ; Peiqiang CHEN ; Zhenyuan QIAN ; Zaiyuan YE
Journal of Chinese Physician 2025;27(10):1451-1454
Objective:To explore the correlation between serum carbohydrate antigen 72-4 (CA72-4) level and pathological differentiation degree of gastric cancer, and to provide reference for early diagnosis, prognosis evaluation and efficacy monitoring of gastric cancer.Methods:A retrospective study was conducted on 136 patients with gastric cancer admitted to Zhejiang Provincial People′s Hospital from April 2022 to December 2024. According to postoperative pathological diagnosis, patients were divided into well-differentiated group ( n=9), moderately differentiated group ( n=36) and poorly/undifferentiated group ( n=91). Preoperative CA72-4 levels and clinical characteristics of patients were collected to analyze the relationship between differentiation degree and CA72-4 level, and to compare the changes of CA72-4 before and after surgery in gastric cancer patients with different differentiation degrees. Results:The preoperative CA72-4 level in the poorly/undifferentiated group was significantly higher than that in the well-differentiated group and moderately differentiated group (all P<0.001). Preoperative CA72-4 level in gastric cancer patients was weakly negatively correlated with differentiation degree ( R=-0.341). After surgery, the CA72-4 level in the poorly/undifferentiated group decreased significantly compared with that before surgery ( P=0.043), while the changes in the well-differentiated group and moderately differentiated group were not significant. Conclusions:There are significant differences in CA72-4 levels among gastric cancer groups with different differentiation degrees. Preoperative CA72-4, as a tumor marker, is of great significance for early diagnosis, prognosis evaluation and postoperative monitoring of gastric cancer. Especially in patients with poorly/undifferentiated gastric cancer, the CA72-4 level is relatively high, which can be used for auxiliary diagnosis and formulation of treatment plans.
10.Computer-aided design of an improved lamina hook and finite element analysis of its use in fixation of lumbar spondylolysis
Hongliang GAO ; Hua LIU ; Tao ZHANG ; Chengwei YANG ; Yizhe WANG ; Zirong HUANG ; Wenhua ZHANG ; Long CHEN ; Bing KANG ; Yuxuan MA ; Songkai LI
Chinese Journal of Trauma 2024;40(7):593-604
Objective:To design an improved lamina hook system and compare its biomechanical properties with traditional lamina hook system in fixation of lumbar spondylolysis.Methods:The thin layer CT data of the lumbosacral vertebrae of 20 healthy young male servicemen who underwent physical examination in the outpatient department of the 940th Hospital of Joint Logistics Support Force of PLA from January 2021 to August 2022 were collected. The age of the subjects was 20-30 years [(25.0±3.0)years]. A 3-dimensional model of the L 5 vertebral body was constructed using the 3-dimensional modeling software. The new improved lamina hook was designed according to the measurements including the thickness of the middle area, the longest longitudinal diameter, the curvature radius of the lower edge, the angle between the upper and lower tail ends, the thickness of the lower edge, and the longest diameter of the lower edge of the bilateral L 5 vertebral plates. One serviceman was selected from the aforementioned group to construct a linear finite element model of segments L 4-S using the 3-dimensional virtual software (normal model, model A), based on which, the L 5 bilateral spondylolysis model (model B), improved lamina hook model (model C) and traditional lamina hook models (model D) were designed. By constraining both sides of the sacrum and applying a longitudinal load of 400 N on the L 4 vertebral body, the upper 1/3 gravity of the body was simulated, and with a bending moment of 10 N·m along the X, Y, and Z directions, motions of forward flexion, backward extension, lateral bending, rotation, etc were simulated. The range of motion of segment L 4/5 and L 5/S 1 of model A was evaluated and compared with the findings of the previous researches to verify its effectiveness. The overall range of motion of models A, B, C, and D, the range of motion of segment L 4/5 and L 5/S 1, the maximum overall displacement, the maximum displacement and stress of the isthmus, the stress distribution and maximum stress of internal fixation of models C and D, and the stress distribution and maximum stress of the vertebral body of models C and D were compared. Results:(1) During forward flexion, backward extension, lateral bending and rotation, the range of motion of model A was 5.01°, 4.03°, 3.91° and 1.42° in segment L 4/5, and was 4.62°, 2.51°, 2.40° and 1.23° in segment L 5/S 1. (2) The overall range of motion, range of motion of segment L 4/5 and L 5/S 1 and maximum overall displacement of models A, C, and D were similar in axial compression, forward flexion, backward extension, left bending, and left rotation, while those of model B were significantly increased. (3) There was no significant difference in the maximum displacement of the isthmus of models A, C, and D under different motion modes, while the maximum displacement of model B in the isthmus was significantly larger than that of models A, C, and D, especially during rotation, increased by 295%, 277%, and 276% respectively. The maximum stress of the isthmus of model C was 0.938 MPa, 1.698 MPa, 0.410 MPa, 2.775 MPa, and 1.554 MPa respectively. The maximum stress in the isthmus of model D was 0.590 MPa, 1.297 MPa, 0.520 MPa, 3.088 MPa, and 2.072 MPa respectively. The maximum stress of the isthmus of models C and D was similar during axial compression and forward flexion, while the stress of the isthmus of model C was smaller than that of model D during backward extension, lateral bending, and rotation, decreased by 21.1%, 10.2%, and 25.0% respectively compared with model D. (4) The maximum stress of internal fixation in models C and D during forward flexion, backward extension, left bending, and left rotation was 135.220 MPa, 130.180 MPa, 200.940 MPa and 306.340 MPa respectively, and was 131.840 MPa, 112.280 MPa, 349.980 MPa and 370.140 MPa respectively. The maximum stress of internal fixation in the two models of internal fixation during forward flexion and backward extension was similar, while it was decreased by 42.6% and 17.2% in model C during left bending and left rotation, compared with model D. (5) The maximum stress of the vertebral body during forward flexion, backward extension, left bending, and left rotation was 79.787 MPa, 36.857 MPa, 37.943 MPa and 96.965 MPa respectively in model C, but was 80.104 MPa, 64.236 MPa, 196.010 MPa and 193.020 MPa respectively in model D. The maximum stress of models C and D was all distributed in the contact area with the internal fixation, and especially during backward extension, left bending, and left rotation, when it was reduced by 42.6%, 80.6%, and 49.8% of model C respectively, compared with that of model D. Conclusions:The improved laminar hook is more consistent with the Chinese anatomized structure of the lamina. Compared with the traditional lamina hook system, the improved lamina hook system can effectively reduce the displacement in all directions and range of motion of lumbar spondylolysis, therefor can significantly reduce the stress of internal fixation and vertebral body and has better biomechanical performance.

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