AIM:To investigate the dynamic changes in ocular surface function after eyelid malignant tumor resection combined with Hughes flap reconstruction.

METHODS:A prospective self-controlled study was conducted. Patients who underwent eyelid malignant tumor resection combined with Hughes tarsoconjunctival flap reconstruction(all tumors occured in the lower eyelid)at Shanxi Eye Hospital from January 2021 to December 2023 were enrolled. The contralateral healthy eye served as control. Ocular surface examinations were performed preoperatively and at 3, 6, 9, and 12 mo postoperatively, including ocular surface disease index(OSDI), tear meniscus height(TMH), non-invasive average tear film break-up time(NiaBUT), tear film lipid layer grading, upper and lower eyelid meibomian gland dropout grading, corneal fluorescein staining, and eye redness index.

RESULTS:A total of 36 patients were enrolled. Two patients were lost to follow-up because they did not complete the scheduled follow-up period, leaving 34 patients with complete data for analysis. The cohort comprised 10 men(29%)and 24 women(71%), with a mean age of 70.08±10.92 y(range 33-81 y). Histopathological diagnoses included basal cell carcinoma(BCC)in 22 eyes(65%), sebaceous gland carcinoma(SGC)in 10 eyes(29%), and squamous cell carcinoma(SCC)in 2 eyes(6%). Tumor size ranged from 4 to 30 mm(mean 12.64±0.31 mm). According to the AJCC staging system, 14 eyes(41%), 18 eyes(53%), and 2 eyes(6%)were classified as T1b, T2b, and T3b, respectively. Preoperatively, OSDI scores were higher in surgical eyes than in contralateral healthy eyes(28.74±13.72 vs 17.47±3.02, P<0.05). OSDI scores in surgical eyes further increased at 6, 9, and 12 mo postoperatively, peaking at 9 mo(all P<0.05), whereas no significant postoperative changes were observed in contralateral healthy eyes. Compared with contralateral healthy eyes, TMH in surgical eyes increased significantly at 3 mo postoperatively and remained elevated thereafter despite a slight decline(all P<0.05). NiaBUT in surgical eyes was shorter than the preoperative value from 3 mo postoperatively onward and was lower than that in contralateral healthy eyes(all P<0.05). Eye redness index in surgical eyes were consistently higher than those in contralateral healthy eyes(all P<0.001). Tear film lipid layer grade and meibomian gland dropout grades in both the upper and lower eyelids were significantly worsened postoperatively compared with baseline(all P<0.001). Corneal fluorescein staining grades were higher in surgical eyes than in contralateral healthy eyes preoperatively(P<0.001)and were higher at 3, 6, 9, and 12 mo postoperatively than at baseline(all P<0.001).

CONCLUSION: After lower eyelid malignant tumor resection combined with Hughes flap reconstruction, evaporative dry eye is the predominant phenotype. Meibomian gland dropout in both upper and lower eyelids appears irreversible within 12 mo postoperatively, and corneal epithelial damage and ocular surface inflammation persist over time.

ObjectiveTo evaluate the clinical efficacy of Huayu Tongluo Formula （化瘀通络方， HTF） in patients with mid-stage diabetic kidney disease of blood stasis syndrome and explore its potential mechanisms. MethodsA multi-center， randomized， double-blind， placebo-controlled clinical trial was conducted. Ninety patients of mid-stage diabetic kidney disease of blood stasis syndrome were divided into a control group of 46 cases and a treatment group of 44 cases. Both groups received conventional western medicine treatment， the treatment group additionally taking HTF， while the control group taking a placebo of the formula. The treatment was administered once daily for 24 weeks. The primary outcomes included 24-hour urine total protein （24 h-UTP）， serum albumin （Alb）， glycated hemoglobin （HbA1c）， and serum creatinine （Scr）.The secondary outcomes included changes in levels of endothelin-1 （ET-1）， nitric oxide （NO）， vascular endothelial growth factor （VEGF）， and traditional Chinese medicine （TCM） syndrome scores before and after treatment. Clinical efficacy was evaluated based on TCM syndrome scores and overall disease outcomes. Adverse reactions and endpoint events were recorded. ResultsIn the treatment group after treatment， 24 h-UTP， ET-1， and VEGF levels significantly decreased （P＜0.05）， Alb and NO levels significantly increased （P＜0.05）； while the TCM syndrome scores for edema， lumbar pain， numbness of limbs， dark purple lips， dark purple tongue or purpura， and thin， rough pulse all significantly decreased （P＜0.05）. In the control group， no significant changes were observed in any of the indicators after treatment （P＞0.05）.Compared with the control group， the treatment group showed significant reductions in 24 h-UTP， ET-1， and VEGF levels， and increases in Alb and NO levels （P＜0.05）. The TCM syndrome scores for edema， lumbar pain， dark purple tongue or purpura， and thin， rough pulse were all lower in the treatment group than in the control group （P＜0.05）. The total effective rate of TCM syndrome in the treatment group was 59.09% （26/44）， and the overall clinical effective rate was 45.45% （20/44）. In the control group， these rates were 15.22% （7/46） and 8.7% （4/46）， respectively， with the treatment group showing significantly better outcomes （P＜0.05）. A total of 7 adverse events occurred across both groups， with no significant difference （P＞0.05）. No endpoint events occurred during the study. ConclusionOn the basis of conventional treatment of Western medicine， HTF can further reduce urinary protein levels and improve clinical symptoms in patients with mid-stage diabetic kidney disease of blood stasis syndrome. The mechanism may be related to its effects on endothelial function.

Objective To explore the efficacy of vacuum-assisted minimally invasive gyrotomy for benign lesions in the lower quadrant of the breast.Methods From August 2022 to August 2023,90 patients with benign lesions in the lower quadrant of the breast were treated.According to the different surgical methods,they were divided into two groups:the traditional group included 45 cases,which underwent surgery through the trans-areolar incision;the minimally invasive group included 45 cases,which underwent surgery through the trans-mammary fold incision with vacuum-assisted minimally invasive technique.The surgical-related indicators,inflammatory response indicators,patient satisfaction,and safety were compared between the two groups.Results The operation time[(20.45±6.18)min],intraoperative bleeding[(7.78±2.23)ml],hospital stay[(4.37±1.05)d],scar length[(2.32±0.42)cm]and healing time[(3.46±1.08)d]in the minimally invasive group were significantly better than those in the traditional group[(34.52±9.46)min,(23.16±6.44)ml,(8.72±2.73)d,(19.14±4.18)cm and(7.37±2.16)d](P＜0.05).The levels of IL-6[(12.14±2.86)ng/L],IL-10[(14.33±3.74)pg/ml],CRP[(13.85±3.11)mg/L],Cor[(131.27±6.43)nmol/L]and NE[(82.55±8.44)in the minimally invasive group at 3 days after surgery ng/ml were increased and VEGF was decreased[(59.72±7.44)mg/L]than the traditional group[(17.23±3.38)ng/L,(19.62±4.88)pg/ml,(28.36±4.67)mg/L,(196.52±8.84)nmol/L,(117.62±7.14)ng/ml and(88.46±7.89)mg/L](P＜0.05).The satisfaction of patients in minimally invasive group(97.78％,44/45)was significantly higher than that in traditional group(82.22％,37/45)(P＜0.05).The incidence of adverse events in minimally invasive group(4.44％,2/45)was significantly lower than that in traditional group(22.22％,10/45)(P＜0.05).Conclusion Vacuum-assisted minimally invasive rotatory excision can optimize surgical indicators,improve serological indicators,enhance patient satisfaction and treatment safety compared to traditional areola incision surgery.

Objective To clarify the biomechanical properties of oblique lumbar interbody fusion(OLIF)combined with lateral plate(LP)fixation under different bone conditions by means of finite element(FE)analysis,so as to provide mechanical basis for clinical practice.Methods The three-dimensional nonlinear L3_5 FE model of the spine was constructed.Different material properties were assigned to each part of the model to establish a model of normal bone(NB),osteopenia(OS)and osteoporosis(OP)of the lumbar spine.OLIF combined with the following three internal fixation models were established.For NB,there were OLIF alone(M0),OLIF+LP fixation(M1),and OLIF+bilateral pedicle screw(BPS)fixation(M2);for OS,there were OLIF alone(N0),OLIF+LP fixation(N1),and OLIF+BPS fixation(N2);for OP,there were OLIF alone(P0),OLIF+LP fixation(P1),and OLIF+BPS fixation(P2).A 500 N load was applied on the upper surface of L3 to represent the weight of the upper body,and a 7.5 N·m moment was used to simulate the vertebral motion under six different conditions:flexion(FL),extension(EX),left bending(LB),right bending(RB),left rotation(LR)and right rotation(RR).The range of motion(ROM)of the fixed segment of NB,OS and OP models was calculated,and the overall stress of the vertebral body,the stress of the cage and the internal fixation device were recorded.Results Compared with the complete model,the stability of each surgical model increased.Compared with M0,ROM of M1 decreased,especially in the LB and RB,which was roughly equivalent to the stability of BPS but weaker than BPS in the control FL and EX direction.The situation in OS and OP model was similar to that in NB.Under the same internal fixation,L4_5 ROM gradually increased with bone deterioration.The overall intervertebral ROM of N1 in the FL direction increased by 16.1％compared with M1,P1 in the FL direction increased by 32.1％compared with M1,and P1 in the FL direction increased by 19.0％compared with N1.With the increase of posterior internal fixation,the overall stress of vertebral body,Cage and internal fixation stress showed a downward trend.Under the same internal fixation,with the loss of bone mass,the overall stress of the model gradually increased.Compared with M0,P0 increased the most in LR,reaching 56.5％.In the NB and OS models,the peak stress of the LP fixation under FL exceeded the minimum yield strength of the material by 22.7％and 33.8％,respectively,and was less than the minimum fatigue strength and yield strength of the material under the rest of the motion.In the OP,the peak stress of the internal fixation exceeded the minimum fatigue strength of the material at FL and EX,and reached 53.3％(＞50％)at FL.Conclusions Under NB and OS,OLIF combined with LP fixation can significantly improve the stability of the surgical segment,especially in LB and RB directions,and the overall stability is weaker than that of BPS fixation.Under OP,FL and EX may increase the risk of internal fixation failure.Combination with BPS fixation should be considered to improve the safety of fixation.

Objective:To investigate the reliability and validity of the China Nanjing consciousness recovery scale(CNCRS)in assessing patients with acute disorder of consciousness(DOC).Method:A total of 306 patients with acute DOC admitted to Nanjing Zijin Hospital between August 2023 and August 2024 were enrolled.Each patient was assessed using both the Glasgow Coma Scale(GCS)and CNCRS.The correlation between GCS and CNCRS scores were analyzed,and the reliability and validity of these two scales were compared.Result:The DOC degree of enrolled patients was severe,with a tracheotomy rate of 61.8%.The median GCS score was 7(5,10)for males and 6(5,9)for females,while the median CNCRS score was 3(1,8)for males and 3(1,7)for females.Scores from both scales were statistically significant correlated across gender groups(P<0.001).The Cron-bach's α coefficient of CNCRS(male 0.918,female 0.889)was higher than that of GCS(male 0.687,female 0.658),indicating superior internal consistency.The validity index Kaiser-Meyer-Olkin(KMO)value(male 0.891,female 0.857)was also higher than the GCS scale(male 0.600,female 0.602),demonstrating better construct validity.Conclusion:The CNCRS demonstrates good reliability and validity and can be effectively applied for the evalu-ation of patients with acute disturbance of consciousness.

Objective:To evaluate the clinical equivalence between a domestic calcipotriol/betamethasone dipropionate ointment and the originator product in the treatment of stable plaque psoriasis.Methods:A multicenter, randomized, double-blind, three-arm, parallel-group, active- and placebo-controlled study was conducted, and 449 patients aged 18 - 65 years with stable plaque psoriasis were enrolled from 25 hospitals (such as the First Affiliated Hospital of China Medical University). Eligible patients had a baseline physician's global assessment (PGA) score of ≥ 3 points, baseline body surface area (BSA) involvement of 5% - 30%, and a target lesion psoriasis area and severity index (TL-PASI) for plaque elevation of ≥ 3 points. Participants were randomly assigned in a 2:2:1 ratio to the test group ( n = 179), reference group ( n = 180), and placebo group ( n = 90), and applied the domestic calcipotriol/betamethasone dipropionate ointment, originator product, and ointment base respectively, once daily in the evening for 4 weeks. Efficacy and safety were assessed at weeks 1, 2, and 4. The primary efficacy endpoints were the treatment success rates and clinical success rates in each group at week 4. The per-protocol set (PPS) was used for the primary efficacy analysis, and the intention-to-treat (ITT) set for supplementary efficacy analysis. Equivalence between the test and reference preparations was tested using the Cochran-Mantel-Haenszel method adjusted for randomization strata. Superiority of the test and reference preparations over the placebo was also tested. Measurement data were compared among the 3 groups using analysis of variance or non-parametric tests, while treatment success rates, clinical success rates, and incidence rates of adverse reactions were compared using the chi-square test. Results:The ITT, PPS, and safety sets included 447, 420, and 448 patients, respectively. In the ITT set, patients were aged 43.6 ± 12.8 years, including 320 (71.6%) males and 127 (28.4%) females, and the disease duration was 11.21 ± 9.05 years; 316 (70.7%) had a PGA score of 3 points and 131 (29.3%) had a PGA score of 4 - 5 points. No significant differences in the baseline characteristics (including age, sex, disease duration and disease severity) were observed among the 3 groups (all P > 0.05). Based on the PPS analysis, the treatment success rates were 57.9% (99/171) in the test group, 50.3% (86/171) in the reference group, and 7.7% (6/78) in the placebo group, and the clinical success rates were 57.9% (99/171), 50.3% (86/171), and 10.3% (8/78), respectively; both the test and reference groups were superior to the placebo group in both treatment and clinical success rates (all P < 0.001) ; the rate differences for treatment success (90% confidence interval [ CI]: -1.3% - 16.4%) and clinical success (90% CI: -1.3% - 16.3%) between the test and reference groups were entirely within the pre-defined equivalence margin (-20% - 20%). Subgroup analyses by baseline PGA scores: for patients with a baseline PGA score of 3 points, the treatment success rates in the test, reference, and placebo groups were 60.8% (73/120), 52.1% (62/119), and 11.1% (6/54), respectively, and the corresponding clinical success rates were 61.7% (74/120), 53.8% (64/119), and 13% (7/54), respectively; the test and reference groups did not differ significantly in treatment or clinical success rates (both P > 0.05), but both showed higher success rates than the placebo group (all P < 0.001) ; the results of statistical comparisons among the 3 groups in patients with a baseline PGA score of 4 - 5 points were consistent with those observed in patients with a baseline PGA score of 3 points. The percentage reductions in PGA and TL-PASI scores from baseline to weeks 1, 2, and 4 showed significant differences among the 3 groups, which were significantly higher in the test and reference groups than in the placebo group (all P < 0.001), but did not differ between the test and reference groups (all P > 0.05). The primary adverse reactions were local skin reactions, such as pruritus, pain, and erythema. The incidence rates of adverse reactions were 8.9% (16/179) in the test group, 7.3% (13/179) in the reference group, and 7.8% (7/90) in the placebo group, with no significant difference among the 3 groups ( P > 0.05) . Conclusions:The domestic calcipotriol/betamethasone dipropionate ointment demonstrated clinical equivalence to the originator product in the treatment of stable plaque psoriasis, and the two agents exhibited comparable efficacy for patients with varying degrees of disease severity, and were comparable in the speed and degree of clinical improvement, with similar favorable safety profiles.

Objective To analyze the distribution and drug resistance patterns of pathogenic bacteria in bile and blood cultures obtained from patients with biliary stones accompanied by acute biliary tract infection,to evaluate the clinical appropriate-ness of antibiotic use based on drug sensitivity results,and to provide evidence for empirical antibiotic treatment in such patients.Methods The clinical data of 161 patients with biliary calculi complicated by acute biliary tract infection who were admitted to the First People's Hospital of Neijiang from 2017 to 2023 were retrospectively analyzed.The results of microbial culture,drug sensitivity analysis,and patient characteristics were assessed to evaluate the appropriateness of clinical antimicrobial therapy.Results Among the 161 patients with positive cultures,212 strains of pathogenic bacteria were detected.The predominant patho-gens were Escherichia coli,Klebsiella pneumoniae subspecies,and Enterococcus faecium.Age and underlying diseases significantly affected the distribution of Escherichia coli and Klebsiella pneumoniae subspecies.Within the gram-negative bacterial group,Esche-richia coli and Klebsiella pneumoniae subspecies exhibited higher drug resistance to commonly used broad-spectrum penicillin,third-generation cephalosporin and quinolones but lower resistance rates to piperacillin and tazobactam;furthermore,elderly indi-viduals aged ≥65 years showed higher resistance rates to ceftriaxone than those under age 65 while people with drug exposure history had higher ceftazidime resistance rates that were statistically significant.In contrast to Enterococcus faecalis which displayed low antimicrobial resistance rates for most drugs tested in this study,Enterococcus faecium demonstrated high levels of antibiotic resistance;however,both Enterococcus faecalis and Enterococcus faecium exhibited zero-resistance rates against vancomycin and tigecycline although this may be attributed to their small sample size in our study cohort.Finally,we found that empirical anti-in-fective drugs,as well as target anti-infective drugs,were not prescribed rationally among these patients due mainly to inappropriate combinations of antibiotics or incorrect dosages.Conclusions The predominant pathogens in patients with acute biliary tract infection are gram-negative bacteria,Gram-positive bacteria,and fungi;however,the potential involvement of anaerobic bacteria should not be overlooked.Vancomycin exhibits sensitivity against gram-positive bacteria,yet the overall rationality of antibiotic usage remains suboptimal.Enhanced clinical testing for pathogenic microorganisms is imperative in the management of biliary stones accompanied by acute biliary tract infection.In contrast,clinical pharmacists should provide comprehensive training on anti-infective drugs to clinicians to facilitate their judicious selection of antibiotics based on drug sensitivity results and prevent the e-mergence of multidrug-resistant bacteria.

Objectives:To investigate the effect and mechanism of mitochondrial targeting peptide SS-31 on senescence and pyroptosis of nucleus pulposus(NP)cells induced by inflammation.Methods:NP cells were isolated and cultured in vitro from 6-week-old male SD rats,and were divided into control group,lipopolysaccharide(LPS)group,and LPS+SS-31 group;And the control group of cells received no treatment,LPS group of cells were treated with 100μg/mL LPS for 24h,and LPS+SS-31 group of cells were pre-treated with SS-31 30min before LPS intervention.The levels of cellular senescence and pyroptosis were assessed in each group using β-galactosidase(SA-β-Gal)staining and westem blot(WB)assay;Transmission electron mi-croscopy and oxygen consumption rate(OCR)assay were used to analyze the mitochondrial function of NP cells in each group;The expressions of phosphorylated nuclear factor-κB-p65(p-NF-κB-p65),cyclic GMP-AMP synthase(cGAS),and interferon stimulating gene(STING)in each group were detected by WB and im-munofluorescence;Hematoxylin-eosin(HE)staining,immunohistochemistry(IHC)staining and WB assay were performed to analyze the effects of in vivo injection of SS-31 on intervertebral disc degeneration,senescence,and pyroptosis.Results:The positive SA-β-Gal staining of NP cells,expression of senescence marker pro-teins(p53,p21),and pyroptosis-related molecules(NLRP3,Caspase-1 p20)were significantly lower in the LPS+SS-31 group compared with the LPS group(P＜0.05);Transmission electron microscopy(TEM)showed that the mitochondrial swelling of NP cells was round,the matrix was translucent,and the interstitial lumen of the mitochondrial cristae was dilated in the LPS group,while the mitochondrial swelling was subsided,and the morphology of mitochondria tended to be normalized in the LPS+SS-31 group.Meanwhile,the maximum respi-ration level of NP cells was significantly enhanced in the LPS+SS-31 group compared with the LPS group(P＜0.05).The results of WB and immunofluorescence showed that LPS significantly up-regulated the expression of p-NF-κB-p65,cGAS,and STING(P＜0.05),while SS-31 pretreatment significantly inhibited the expression of p-NF-κB-p65,cGAS and STING in NP cells induced by LPS(P＜0.05).Finally,in vivo experiments con-firmed that local injection of SS-31 reduced the senescence and pyroptosis of NP cells,and alleviated the degeneration of intervertebral disc induced by annulus fibropuncture.Conclusions:SS-31 alleviates inflamma-tion-induced senescence and pyroptosis of NP cells,which is related to the inhibition of NF-κB signaling pathway and cGAS/STING signaling pathway.

Objective:To evaluate the clinical equivalence between a domestic calcipotriol/betamethasone dipropionate ointment and the originator product in the treatment of stable plaque psoriasis.Methods:A multicenter, randomized, double-blind, three-arm, parallel-group, active- and placebo-controlled study was conducted, and 449 patients aged 18 - 65 years with stable plaque psoriasis were enrolled from 25 hospitals (such as the First Affiliated Hospital of China Medical University). Eligible patients had a baseline physician's global assessment (PGA) score of ≥ 3 points, baseline body surface area (BSA) involvement of 5% - 30%, and a target lesion psoriasis area and severity index (TL-PASI) for plaque elevation of ≥ 3 points. Participants were randomly assigned in a 2:2:1 ratio to the test group ( n = 179), reference group ( n = 180), and placebo group ( n = 90), and applied the domestic calcipotriol/betamethasone dipropionate ointment, originator product, and ointment base respectively, once daily in the evening for 4 weeks. Efficacy and safety were assessed at weeks 1, 2, and 4. The primary efficacy endpoints were the treatment success rates and clinical success rates in each group at week 4. The per-protocol set (PPS) was used for the primary efficacy analysis, and the intention-to-treat (ITT) set for supplementary efficacy analysis. Equivalence between the test and reference preparations was tested using the Cochran-Mantel-Haenszel method adjusted for randomization strata. Superiority of the test and reference preparations over the placebo was also tested. Measurement data were compared among the 3 groups using analysis of variance or non-parametric tests, while treatment success rates, clinical success rates, and incidence rates of adverse reactions were compared using the chi-square test. Results:The ITT, PPS, and safety sets included 447, 420, and 448 patients, respectively. In the ITT set, patients were aged 43.6 ± 12.8 years, including 320 (71.6%) males and 127 (28.4%) females, and the disease duration was 11.21 ± 9.05 years; 316 (70.7%) had a PGA score of 3 points and 131 (29.3%) had a PGA score of 4 - 5 points. No significant differences in the baseline characteristics (including age, sex, disease duration and disease severity) were observed among the 3 groups (all P > 0.05). Based on the PPS analysis, the treatment success rates were 57.9% (99/171) in the test group, 50.3% (86/171) in the reference group, and 7.7% (6/78) in the placebo group, and the clinical success rates were 57.9% (99/171), 50.3% (86/171), and 10.3% (8/78), respectively; both the test and reference groups were superior to the placebo group in both treatment and clinical success rates (all P < 0.001) ; the rate differences for treatment success (90% confidence interval [ CI]: -1.3% - 16.4%) and clinical success (90% CI: -1.3% - 16.3%) between the test and reference groups were entirely within the pre-defined equivalence margin (-20% - 20%). Subgroup analyses by baseline PGA scores: for patients with a baseline PGA score of 3 points, the treatment success rates in the test, reference, and placebo groups were 60.8% (73/120), 52.1% (62/119), and 11.1% (6/54), respectively, and the corresponding clinical success rates were 61.7% (74/120), 53.8% (64/119), and 13% (7/54), respectively; the test and reference groups did not differ significantly in treatment or clinical success rates (both P > 0.05), but both showed higher success rates than the placebo group (all P < 0.001) ; the results of statistical comparisons among the 3 groups in patients with a baseline PGA score of 4 - 5 points were consistent with those observed in patients with a baseline PGA score of 3 points. The percentage reductions in PGA and TL-PASI scores from baseline to weeks 1, 2, and 4 showed significant differences among the 3 groups, which were significantly higher in the test and reference groups than in the placebo group (all P < 0.001), but did not differ between the test and reference groups (all P > 0.05). The primary adverse reactions were local skin reactions, such as pruritus, pain, and erythema. The incidence rates of adverse reactions were 8.9% (16/179) in the test group, 7.3% (13/179) in the reference group, and 7.8% (7/90) in the placebo group, with no significant difference among the 3 groups ( P > 0.05) . Conclusions:The domestic calcipotriol/betamethasone dipropionate ointment demonstrated clinical equivalence to the originator product in the treatment of stable plaque psoriasis, and the two agents exhibited comparable efficacy for patients with varying degrees of disease severity, and were comparable in the speed and degree of clinical improvement, with similar favorable safety profiles.

Objective To clarify the biomechanical properties of oblique lumbar interbody fusion(OLIF)combined with lateral plate(LP)fixation under different bone conditions by means of finite element(FE)analysis,so as to provide mechanical basis for clinical practice.Methods The three-dimensional nonlinear L3_5 FE model of the spine was constructed.Different material properties were assigned to each part of the model to establish a model of normal bone(NB),osteopenia(OS)and osteoporosis(OP)of the lumbar spine.OLIF combined with the following three internal fixation models were established.For NB,there were OLIF alone(M0),OLIF+LP fixation(M1),and OLIF+bilateral pedicle screw(BPS)fixation(M2);for OS,there were OLIF alone(N0),OLIF+LP fixation(N1),and OLIF+BPS fixation(N2);for OP,there were OLIF alone(P0),OLIF+LP fixation(P1),and OLIF+BPS fixation(P2).A 500 N load was applied on the upper surface of L3 to represent the weight of the upper body,and a 7.5 N·m moment was used to simulate the vertebral motion under six different conditions:flexion(FL),extension(EX),left bending(LB),right bending(RB),left rotation(LR)and right rotation(RR).The range of motion(ROM)of the fixed segment of NB,OS and OP models was calculated,and the overall stress of the vertebral body,the stress of the cage and the internal fixation device were recorded.Results Compared with the complete model,the stability of each surgical model increased.Compared with M0,ROM of M1 decreased,especially in the LB and RB,which was roughly equivalent to the stability of BPS but weaker than BPS in the control FL and EX direction.The situation in OS and OP model was similar to that in NB.Under the same internal fixation,L4_5 ROM gradually increased with bone deterioration.The overall intervertebral ROM of N1 in the FL direction increased by 16.1％compared with M1,P1 in the FL direction increased by 32.1％compared with M1,and P1 in the FL direction increased by 19.0％compared with N1.With the increase of posterior internal fixation,the overall stress of vertebral body,Cage and internal fixation stress showed a downward trend.Under the same internal fixation,with the loss of bone mass,the overall stress of the model gradually increased.Compared with M0,P0 increased the most in LR,reaching 56.5％.In the NB and OS models,the peak stress of the LP fixation under FL exceeded the minimum yield strength of the material by 22.7％and 33.8％,respectively,and was less than the minimum fatigue strength and yield strength of the material under the rest of the motion.In the OP,the peak stress of the internal fixation exceeded the minimum fatigue strength of the material at FL and EX,and reached 53.3％(＞50％)at FL.Conclusions Under NB and OS,OLIF combined with LP fixation can significantly improve the stability of the surgical segment,especially in LB and RB directions,and the overall stability is weaker than that of BPS fixation.Under OP,FL and EX may increase the risk of internal fixation failure.Combination with BPS fixation should be considered to improve the safety of fixation.