BACKGROUND:Autologous bone,allogeneic bone or artificial bone has been used to promote bone defect repair in the clinic,but the rate of non-healing is still high.The key is to ignore the importance of periosteum in the bone healing process.In the early stage of the project,the project team constructed an electrospinning membrane loaded with vascular endothelial growth factor to highly simulate the intramembranous osteogenesis of natural periosteum at the bone defect site,which promoted bone regeneration to a certain extent.However,the injured area often faces the dilemma of severe inflammatory response mediated by macrophages and lack of seed cells,resulting in the risk of inactivation or diffusion of delivered biological factors.Therefore,it is necessary to further optimize and coordinate the immune regulation and angiogenesis functions of biomimetic periosteum to promote bone repair.OBJECTIVE:To investigate the physicochemical properties of stem cell-engineered bionic periosteum and its role in regulating the inflammatory microenvironment to promote bone repair.METHODS:By combining L-polylactic acid-based microsol electrospinning,type Ⅰ collagen self-assembly and gel stem cell transplantation technology,a bionic periosteum(M@C-B)was constructed,in which the core layer loaded with vascular endothelial growth factor and the shell layer delivered bone marrow mesenchymal stem cells to regulate the immune microenvironment of bone defects.The physicochemical properties of the periosteum were characterized by scanning electron microscopy,transmission electron microscopy,and Fourier transform infrared spectroscopy.A co-culture system was established between the bionic periosteum and macrophages,bone marrow mesenchymal stem cells and human umbilical vein endothelial cells to explore immune regulation and in vitro osteogenic and angiogenic abilities.Finally,the osteogenic properties of the stem cell engineered bionic periosteum were further verified in a rat femoral condyle defect model.RESULTS AND CONCLUSION:(1)Transmission electron microscopy results showed that the micro-sol electrospinning(MS)formed a distinct core-shell structure.Scanning electron microscopy indicated that after the assembly of the collagen-l artificial periosteum(M@C)on the surface of the vascular endothelial growth factor-loaded micro-sol,a distinct"spider web-like"fibrous structure was deposited.Infrared spectroscopy further confirmed the successful self-assembly of collagen-l.Release experiments demonstrated that the M@C group mitigated the burst release phenomenon compared to the MS group,maintaining internal vascular endothelial growth factor activity and sustained release.(2)Live/dead cell staining and CCK-8 assay showed that bone marrow mesenchymal stem cells proliferated well and survived on three types of artificial periosteum:MS,purely aligned poly(L-lactic acid)(PLLA)surface self-assembled collagen-l artificial periosteum(PLLA@C),and vascular endothelial growth factor-loaded micro-sol fiber surface self-assembled collagen-l-bone marrow mesenchymal stem cells artificial periosteum(M@C-B).Among them,the M@C-B group had the highest number of live cells and the fastest proliferation rate.(3)Alkaline phosphatase staining,alizarin red staining,and osteopontin immunofluorescence staining showed that the PLLA@C and M@C-B groups significantly promoted osteogenic differentiation of bone marrow mesenchymal stem cells.Angiogenesis experiments demonstrated that the vascular endothelial growth factor-loaded groups(MS and M@C-B)had longer blood vessel lengths and more reticular vascular-like structures with more cross-linked nodes,with the M@C-B group being the most prominent.(4)Immunofluorescence and flow cytometry showed that artificial periosteum in the M@C-B group significantly inhibited the pro-inflammatory macrophage phenotype and promoted the polarization of macrophages towards the anti-inflammatory M2 phenotype.(5)In vivo studies further confirmed that the M@C-B group showed superior bone mineral density,trabecular thickness,relative bone volume,and trabecular spacing compared to other groups.(6)These results indicate that bone marrow mesenchymal stem cell-engineered artificial periosteum,through the rapid regulation of the bone defect immune microenvironment by the collagen-l-bone marrow mesenchymal stem cells outer phase and the sustained release of vascular endothelial growth factor by the micro-sol electrospinning core-shell structure of the inner phase,synergistically promotes bone healing.

OBJECTIVE To develope a predictive model for medication deviation risks during the hospital-to-home transition period in coronary heart disease （CHD） patients with initial treatment， aiming to assist medical staff in rapidly identifying high-risk groups for medication deviation. METHODS A total of 462 CHD patients with initial treatment from the Affiliated Hospital of North China University of Science and Technology （hereinafter referred to as “our hospital”） between January and July 2024 were enrolled. The patients were randomly divided into a modeling group and an internal validation group. The modeling group was further categorized into a medication deviation group and a non-medication deviation group based on whether medication deviations occurred. Similarly， 57 CHD patients with initial treatment from the cardiology department of our hospital between June and September 2025 were collected as an external validation group. Univariate analysis was used to screen predictive factors， followed by multivariate Logistic regression to construct the predictive model. Internal validation methods were employed to evaluate model performance， while external validation methods were used to test the model’s generalizability. RESULTS The 462 patients were divided into a modeling group （319 cases） and an internal validation group （143 cases）. In the modeling group， the medication deviation group （192 cases， 60.19%） and the non-medication deviation group （127 cases， 39.81%） were identified. Multivariate Logistic regression analysis revealed that age， medication type， medication adherence， and self-efficacy in rational medication use were predictive factors for medication deviations in CHD patients with initial treatment （ P ＜0.05）. The predictive model equation was logit P ＝ln[ P /（1－ P ） ] ＝1.321+1.732×age+4.091×medication type －4.360×medication adherence －3.081×self-efficacy in rational medication use. The model demonstrated good discrimination， with a Hosmer-Lemeshow goodness-of-fit test P -value of 0.439， an area under the receiver operating characteristic curve （AUC） of 0.870， sensitivity of 0.970， and specificity of 0.607. A risk nomogram with a total score of 350 points and a cutoff value of 110 points was plotted. The internal validation group showed an AUC o f 0.787 and a prediction accuracy of 77.6%， while the external validation group exhibited an AUC of 0.802 and a prediction accuracy of 73.7%. CONCLUSIONS This study successfully developed a predictive model for medication deviation risks during the hospital-to-home transition period in CHD patients with initial treatment. The model demonstrates excellent discrimination and predictive accuracy， effectively identifying high-risk populations for medication deviations. Age （＞70 years）， number of drug types≥5， poor medication adherence， and poor self-efficacy in rational medication use are independent risk factors for medication deviations.

BACKGROUND:Autologous bone,allogeneic bone or artificial bone has been used to promote bone defect repair in the clinic,but the rate of non-healing is still high.The key is to ignore the importance of periosteum in the bone healing process.In the early stage of the project,the project team constructed an electrospinning membrane loaded with vascular endothelial growth factor to highly simulate the intramembranous osteogenesis of natural periosteum at the bone defect site,which promoted bone regeneration to a certain extent.However,the injured area often faces the dilemma of severe inflammatory response mediated by macrophages and lack of seed cells,resulting in the risk of inactivation or diffusion of delivered biological factors.Therefore,it is necessary to further optimize and coordinate the immune regulation and angiogenesis functions of biomimetic periosteum to promote bone repair.OBJECTIVE:To investigate the physicochemical properties of stem cell-engineered bionic periosteum and its role in regulating the inflammatory microenvironment to promote bone repair.METHODS:By combining L-polylactic acid-based microsol electrospinning,type Ⅰ collagen self-assembly and gel stem cell transplantation technology,a bionic periosteum(M@C-B)was constructed,in which the core layer loaded with vascular endothelial growth factor and the shell layer delivered bone marrow mesenchymal stem cells to regulate the immune microenvironment of bone defects.The physicochemical properties of the periosteum were characterized by scanning electron microscopy,transmission electron microscopy,and Fourier transform infrared spectroscopy.A co-culture system was established between the bionic periosteum and macrophages,bone marrow mesenchymal stem cells and human umbilical vein endothelial cells to explore immune regulation and in vitro osteogenic and angiogenic abilities.Finally,the osteogenic properties of the stem cell engineered bionic periosteum were further verified in a rat femoral condyle defect model.RESULTS AND CONCLUSION:(1)Transmission electron microscopy results showed that the micro-sol electrospinning(MS)formed a distinct core-shell structure.Scanning electron microscopy indicated that after the assembly of the collagen-l artificial periosteum(M@C)on the surface of the vascular endothelial growth factor-loaded micro-sol,a distinct"spider web-like"fibrous structure was deposited.Infrared spectroscopy further confirmed the successful self-assembly of collagen-l.Release experiments demonstrated that the M@C group mitigated the burst release phenomenon compared to the MS group,maintaining internal vascular endothelial growth factor activity and sustained release.(2)Live/dead cell staining and CCK-8 assay showed that bone marrow mesenchymal stem cells proliferated well and survived on three types of artificial periosteum:MS,purely aligned poly(L-lactic acid)(PLLA)surface self-assembled collagen-l artificial periosteum(PLLA@C),and vascular endothelial growth factor-loaded micro-sol fiber surface self-assembled collagen-l-bone marrow mesenchymal stem cells artificial periosteum(M@C-B).Among them,the M@C-B group had the highest number of live cells and the fastest proliferation rate.(3)Alkaline phosphatase staining,alizarin red staining,and osteopontin immunofluorescence staining showed that the PLLA@C and M@C-B groups significantly promoted osteogenic differentiation of bone marrow mesenchymal stem cells.Angiogenesis experiments demonstrated that the vascular endothelial growth factor-loaded groups(MS and M@C-B)had longer blood vessel lengths and more reticular vascular-like structures with more cross-linked nodes,with the M@C-B group being the most prominent.(4)Immunofluorescence and flow cytometry showed that artificial periosteum in the M@C-B group significantly inhibited the pro-inflammatory macrophage phenotype and promoted the polarization of macrophages towards the anti-inflammatory M2 phenotype.(5)In vivo studies further confirmed that the M@C-B group showed superior bone mineral density,trabecular thickness,relative bone volume,and trabecular spacing compared to other groups.(6)These results indicate that bone marrow mesenchymal stem cell-engineered artificial periosteum,through the rapid regulation of the bone defect immune microenvironment by the collagen-l-bone marrow mesenchymal stem cells outer phase and the sustained release of vascular endothelial growth factor by the micro-sol electrospinning core-shell structure of the inner phase,synergistically promotes bone healing.

Objective:To investigate the predictive value of transabdominal uterine electromyography for pre-term labor after tocolysis in women with threatened preterm labor.Methods:A total of 48 pregnant women at 28-34 weeks of gestation diagnosed with threatened preterm labor and admitted to The Fourth Affiliated Hospital of Soo-chow University from January to September 2023 were included.According to the response to tocolysis and whether the pregnancy was prolonged for at least 48 h,women were divided into two groups:non-preterm birth within 48 h(n=35)and preterm birth within 48 h(n=13).Uterine electromyography parameters and difference were compared before and after tocolytic therapy in two groups.Univariate Logistic regression was performed to predict the related factors of preterm birth within 48 h after the using of tocolysis in pregnant women with threat-ened preterm birth by uterine electromyography,and receiver operating characteristic(ROC)curve was per-formed to evaluate their performance.Results:Compared to before treatment with tocolysis,after therapy,in the non-preterm birth within 48 h group,significant reductions in contraction frequency,area,duration and amplitude were observed(P<0.05).In the preterm birth within 48 h group,only contraction frequency decreased significant-ly(P<0.05).Univariate Logistic regression indicated that contraction frequency,contraction duration,and contrac-tion area were predictive factors for premature birth within 48 h after tocolysis(P<0.05).When the duration of u-terine contractions lasting for 104.55 s or more the sensitivity and specificity of predicting premature birth within 48 h are 92.3％and 68.6％,respectively.Conclusions:Uterine electromyography may predict the premature birth within 48 h after tocolytic treatment in preterm labor,which may provide reference for subsequent corticosteroid therapy or transfer of high-risk pregnant patients.

Aim To investigate the related influencing factors of major adverse cardiovascular events(MACE)in coronary heart disease(CHD)patients with type 2 diabetes mellitus(T2DM)based on prognostic nutritional index(PNI),and to construct a prediction model.Methods The clinical data of 391 patients with CHD combined with T2DM who were hospitalised in the Department of Cardiovascular Medicine of Hebei Provincial People's Hospital from Janu-ary 2022 to January 2023 were collected and followed up for 1 year,and were divided into the MACE group(n=99)and the non-MACE group(n=292)according to the presence or absence of the occurrence of MACE,and were divided into the training set(n=273)and the validation set(n=118)in a ratio of 7:3 by using the computer-generated random number method,and the patients in the training set were divided into the MACE(n=67)group and the non-MACE group(n=206)according to whether they had MACE or not.Lasso regression was used to screen the relevant influencing factors and to construct the prediction model of the column-line diagram,and the prediction model was validated by plotting receiv-er operating characteristic(ROC)curve,calibration curve,decision curve analysis(DCA),and clinical impact curve(CIC).Results Lasso regression showed that the use of angiotensin receptor neprilysin inhibitor(ARNI),fasting blood glucose(FBG),C-reactive protein(CRP),platelet to lymphocyte ratio(PLR),lipoprotein(a)(Lp(a)),and PNI were the predictors of the occurrence of MACE in patients with CHD combined with T2DM.A column-line graph pre-diction model was constructed and validated based on the above predictors,and the area under the ROC curve(AUC)was 0.838(95％CI:0.778～0.898)in the training set and0.872(95％CI:0.803～0.942)in the validation set,with a good discriminatory degree of the model,and the C-values of the calibration curves in the training set and the validation set were 0.838 and 0.872,respectively,with good fit.The results of the decision curve analysis and the clinical impact curve showed that the column-line graph prediction model had a higher net yield of MACE in patients with CHD combined with T2DM,with high clinical utility.Conclusion PNI is an influential factor in the occurrence of MACE in patients with CHD combined with T2DM,and the column-line graphical model constructed on the basis of predictors such as PNI is con-venient for clinical use and has high predictive value in predicting the occurrence of MACE in patients with CHD combined with T2DM.

Aim To investigate the related influencing factors of major adverse cardiovascular events(MACE)in coronary heart disease(CHD)patients with type 2 diabetes mellitus(T2DM)based on prognostic nutritional index(PNI),and to construct a prediction model.Methods The clinical data of 391 patients with CHD combined with T2DM who were hospitalised in the Department of Cardiovascular Medicine of Hebei Provincial People's Hospital from Janu-ary 2022 to January 2023 were collected and followed up for 1 year,and were divided into the MACE group(n=99)and the non-MACE group(n=292)according to the presence or absence of the occurrence of MACE,and were divided into the training set(n=273)and the validation set(n=118)in a ratio of 7:3 by using the computer-generated random number method,and the patients in the training set were divided into the MACE(n=67)group and the non-MACE group(n=206)according to whether they had MACE or not.Lasso regression was used to screen the relevant influencing factors and to construct the prediction model of the column-line diagram,and the prediction model was validated by plotting receiv-er operating characteristic(ROC)curve,calibration curve,decision curve analysis(DCA),and clinical impact curve(CIC).Results Lasso regression showed that the use of angiotensin receptor neprilysin inhibitor(ARNI),fasting blood glucose(FBG),C-reactive protein(CRP),platelet to lymphocyte ratio(PLR),lipoprotein(a)(Lp(a)),and PNI were the predictors of the occurrence of MACE in patients with CHD combined with T2DM.A column-line graph pre-diction model was constructed and validated based on the above predictors,and the area under the ROC curve(AUC)was 0.838(95％CI:0.778～0.898)in the training set and0.872(95％CI:0.803～0.942)in the validation set,with a good discriminatory degree of the model,and the C-values of the calibration curves in the training set and the validation set were 0.838 and 0.872,respectively,with good fit.The results of the decision curve analysis and the clinical impact curve showed that the column-line graph prediction model had a higher net yield of MACE in patients with CHD combined with T2DM,with high clinical utility.Conclusion PNI is an influential factor in the occurrence of MACE in patients with CHD combined with T2DM,and the column-line graphical model constructed on the basis of predictors such as PNI is con-venient for clinical use and has high predictive value in predicting the occurrence of MACE in patients with CHD combined with T2DM.

Objective:To study the comprehensive surgical treatment of brucellosis with chest wall cysts as the main manifestation.Methods:Retrospective analysis was made on the general information epidemiological characteristics, clinical manifestations, laboratory examinations, imaging examinations, treatment and outcomes of five patients with brucellosis mainly manifested by chest wall cysts admitted to the 948 Hospital of the People's Liberation Army from July 2019 to June 2022.Results:Among the 5 patients, there were 4 males and 1 female, aged between 23 and 64 years old, with a clear history of contact with cattle and sheep. The main clinical manifestation was painless cystic masses on the chest wall. Both the serum tiger red plate agglutination test (RBPT) and the test tube agglutination test (SAT) were positive. Four cases were infected with Brucella and one case was infected with Actinobacillus pleuropneumoniae (considered as Brucella infection based on the overall condition). All patients exhibited abnormal chest wall signals (manifesting as hypointense on T1-weighted imaging and hyperintense on T2-weighted imaging) on magnetic resonance imaging(MRI), and were ultimately diagnosed with brucellosis presenting predominantly as chest wall cysts. After complete removal of the chest wall cyst through surgery, a combination treatment of rifampicin capsules and doxycycline hyclate tablets was given for 6 weeks. There were no significant adverse reactions and the wound healed in one stage. During the postoperative follow-up period of 11 - 40 months, MRI reexamination demonstrated no evidence of chest wall cyst recurrence, and all SAT results were negative. Conclusions:Patients with brucellosis presenting as chest wall cysts are clinically rare and lack specific symptoms. Surgical resection of the affected lesion combined with early, standardized, combined, and full course antimicrobial therapy results in a good prognosis for the patient.

Objective:To investigate the predictive value of transabdominal uterine electromyography for pre-term labor after tocolysis in women with threatened preterm labor.Methods:A total of 48 pregnant women at 28-34 weeks of gestation diagnosed with threatened preterm labor and admitted to The Fourth Affiliated Hospital of Soo-chow University from January to September 2023 were included.According to the response to tocolysis and whether the pregnancy was prolonged for at least 48 h,women were divided into two groups:non-preterm birth within 48 h(n=35)and preterm birth within 48 h(n=13).Uterine electromyography parameters and difference were compared before and after tocolytic therapy in two groups.Univariate Logistic regression was performed to predict the related factors of preterm birth within 48 h after the using of tocolysis in pregnant women with threat-ened preterm birth by uterine electromyography,and receiver operating characteristic(ROC)curve was per-formed to evaluate their performance.Results:Compared to before treatment with tocolysis,after therapy,in the non-preterm birth within 48 h group,significant reductions in contraction frequency,area,duration and amplitude were observed(P<0.05).In the preterm birth within 48 h group,only contraction frequency decreased significant-ly(P<0.05).Univariate Logistic regression indicated that contraction frequency,contraction duration,and contrac-tion area were predictive factors for premature birth within 48 h after tocolysis(P<0.05).When the duration of u-terine contractions lasting for 104.55 s or more the sensitivity and specificity of predicting premature birth within 48 h are 92.3％and 68.6％,respectively.Conclusions:Uterine electromyography may predict the premature birth within 48 h after tocolytic treatment in preterm labor,which may provide reference for subsequent corticosteroid therapy or transfer of high-risk pregnant patients.

Objective To investigate the correlation of SII with occurrence of short-term MI in eld-erly patients with CHD complicated with T2DM.Methods A total of 382 CHD patients with con-comitant T2DM admitted in our hospital from January 2022 to January 2023 were enrolled,and according to occurrence of MI within 1 year,they were divided into a MI group(83 patients)and a non-MI group(299 patients).Clinical data were collected,and multivariate logistic regression analysis was used to determine the risk factors for MI in the patients.ROC curve was plotted to evaluate the predictive value of SII,fasting blood glucose(FPG)and their combination for 1-year MI occurrence.Kaplan-Meier curve was drawn to analyze the relationship between SII and MI.Results Multivariate logistic regression analysis showed that SII,FPG and peripheral atheroscle-rosis were risk factors for MI occurrence(OR=1.001,95％CI:1.000-1.001,P=0.001;OR=1.106,95％CI:1.016-1.203,P=0.020;OR=4.798,95％CI:2.621-8.786,P=0.000),and GLP-1RA and SGLT2i were protective factors for the occurrence(OR=0.255,95％CI:0.073-0.895,P=0.033;OR=0.474,95％CI:0.270-0.834,P=0.010).ROC curve analysis indicated showed that the AUC value of SII,FPG and their combination was 0.675,0.619 and 0.702,respectively,and the predictive performance was better in the combination than the indicator alone(P＜0.01).Kaplan-Meier curve analysis revealed that the cumulative survival rate in the high-level group was significantly lower than that in the low-level group(Plog rank＜0.01).Conclusion For the elderly T2DM patients with concomitant CHD,SII,FPG and atherosclerosis are independ-ent risk factors for MI occurrence.SII and FPG have certain predictive value for the occurrence.

Objective:To investigate spinal cord morphological changes and risk factors in upper cervical spine surgery using C 2 medial "in-out-in" pedicle screws in patients with atlantoaxial dislocation (AAD) and high-riding vertebral artery (HRVA). Methods:A retrospective analysis was conducted on 41 patients with AAD who underwent C 2 medial "in-out-in" pedicle screw implantation at our hospital between January 2019 and December 2023. The cohort included 12 males and 29 females, with a mean age of 47.6±10.3 years (range: 18-68 years). Among them, 30 patients received unilateral C 2 medial "in-out-in" screws, while 11 patients received bilateral screws. All patients underwent posterior reduction and internal fixation. Measurements included C 2 pedicle height, C 2 pedicle width, C 2 horizontal spinal canal width, screw invasion distance into the spinal canal, and spinal canal invasion rate based on CT findings. MRI evaluations included spinal canal-dura mater distance, dura mater-spinal cord distance, spinal canal-spinal cord distance, and spinal cord cross-sectional area. The change rate of spinal cord cross-sectional area was calculated and categorized into >20% decrease group (decreasing group) and ≤20% decrease group (non-decreasing group). Postoperative outcomes were assessed using the Visual Analogue Scale (VAS) and Japanese Orthopedic Association (JOA) scores. Results:The mean operative time was 165.5±30.1 minutes (range: 120-220 minutes). No spinal cord vascular injuries or severe complications were observed. However, five patients experienced cerebrospinal fluid (CSF) leakage, requiring delayed removal of drainage tubes, but their wounds healed successfully. Follow-ups (range: 6-24 months) showed no loosening of internal fixation, fractures, or bone graft nonunion, with a 100% bone fusion rate at 6 months postoperatively. VAS scores improved significantly from a preoperative median of 5.0 (3.5, 6.0) (range: 1-7) to 2.0 (2.0, 3.0) at 3 months and 1.0 (1.0, 1.0) at 6 months ( Z=36.716, P< 0.001). JOA scores improved from 10.0 (9.0, 12.0) (range: 4-14) preoperatively to 13.0 (11.0, 13.5) at 3 months and 14.0 (12.0, 15.0) at 6 months ( Z=67.093, P<0.001). The height of C 2 pedicle was 5.50±1.78 mm, the width of C 2 pedicle was 2.27±1.23 mm, the width of C 2 horizontal spinal canal was 23.76±4.91 mm, the spinal canal-dura mater distance was 3.08±0.85 mm, dura mater-spinal cord distance was 3.23±0.85 mm, the spinal canal-spinal cord distance was 6.31±1.11 mm, the distance of screw invasion into the spinal canal was 2.80±1.54 mm, the rate of spinal canal invasion was 12.1%±6.8%, the preoperative spinal cord cross-sectional area was 69.81±13.27 mm 2, and the postoperative spinal cord cross-sectional area was 68.81±13.94 mm 2. Based on spinal cord cross-sectional area changes, 32 patients were classified into the non-decreasing group, and 9 patients into the decreasing group. The intraclass correlation coefficient (ICC) values ranged from 0.733 to 0.984, indicating high measurement reliability. There were significant differences in the proportion of C 2 bilateral medial "in-out-in" screws (χ 2=6.903, P=0.009), the incidence of CSF leakage (χ 2=15.391, P<0.001), the distance of screw invasion into the spinal canal ( t=4.990, P<0.001) and the rate of spinal canal invasion ( t=4.045, P<0.001) in the decreasing group versus the non-decreasing group. The JOA scores of the non-decreasing group were significantly higher at 3 and 6 months postoperatively compared to the decreasing group ( P<0.05). No other parameters showed significant differences between the groups. Binary logistic regression analysis identified spinal canal invasion rate [ OR=1.963, 95% CI (1.010, 3.817), P=0.047] as an independent risk factor for spinal cord cross-sectional area reduction. The Jordan index was 0.875, with a spinal canal invasion rate threshold of 14.18%, a sensitivity of 1.000, a specificity of 0.875, and an AUC of 0.983, indicating strong predictive value. Conclusion:The C 2 medial "in-out-in" screw technique provides effective posterior fixation and fusion for AAD patients with HRVA. However, to minimize spinal cord morphological changes and associated risks, the spinal canal invasion rate should be kept below 14.18% when using this technique.