This study was aimed at investigating the immunoregulatory function of Mycobacterium tuberculosis Rv3641c gene in modulating host type Ⅰ interferon responses.The shuttle plasmid pMV261 was used to construct Rv3641c overexpression recombinant Mycobacterium smegmatis,and the biological characteristics of the recombinant bacteria were analyzed to explore the effect of Rv3641c on the growth curve,colony morphology and stress resistance of Mycobacterium.Subsequently,RAW264.7 cells were infected with Rv3641c overexpressing Mycobacterium smegmatis,and the transcriptional expression of genes related to the inhibition of type I inter-feron pathway was determined by RT-PCR.The expression level of IFN-βprotein was determined by ELISA,and the intracellular sur-vival level was determined.As a result,the recombinant rMS::pMV261-Rv3641c was successfully constructed.The results of biologi-cal characteristics analysis showed that Rv3641c did not affect the growth of mycobacteria,but significantly changed the colony mor-phology of mycobacteria and improved its resistance to H2O2.The results of recombinant bacteria infection experiments showed that Rv3641c significantly down-regulated the transcription levels of IFN-α,IFN-βand downstream ISGs genes CXCL10,IFIT2 and IL-1β in host cells,and Rv3641c significantly down-regulated the transcription levels of IFN-α,IFN-βand downstream ISGs genes CXCL10,IFIT2 and IL-1βin host cells.The results of intracellular colonization experiments showed that the intracellular mycobacte-ria in the overexpression recombinant bacteria infection group were significantly higher than those in the empty vector group,indicat-ing that Rv3641c could promote the intracellular surviv al of mycobacteria.In summary,the Rv3641c gene of M.tuberculosis can inhibit the host type I interferon response and promote the intracellular survival of M.tuberculosis,which provides a new idea for further explor-ing the immune escape function of M.tuberculosis and the discovery of new targets for anti-tuberculosis drugs.

Objective:To investigate the influencing factors and perinatal outcomes associated with monozygotic twins (MZT) following elective single embryo transfer (eSET) via in vitro fertilization or intracytoplasmic sperm injection and embryo transfer (IVF/ICSI-ET). Methods:A retrospective cohort study was conducted on 12 079 patients who achieved pregnancy after undergoing IVF/ICSI-eSET at Reproductive Health Hospital of the Third Affiliated Hospital of Zhengzhou University between January 2015 and September 2023. Patients were stratified into two groups based on ultrasound findings 30 d post-transfer: singleton pregnancy group and MZT pregnancy group. Finally, 300 MZT and 1 500 single pregnancies, which were randomly matched according to 1∶5 were included by study period. General patients' characteristics, embryo-related factors, and perinatal outcomes were compared between the two groups. A multivariate logistic regression model was employed to identify risk factors for MZT after single embryo transfer, adjusting for potential confounding variables.Results:The incidence of twin pregnancy following single embryo transfer was 2.48% (300/12 079), which was higher than that of naturally conceived monozygotic twin pregnancy. No significant difference was found in baseline characteristics between the two groups (all P>0.05). The blastocyst transfer rate was higher in the MZT pregnancy group [93.3% (280/300)] than in the singleton pregnancy group [88.8% (1 332/1 500), P=0.022]. Multivariate logistic regression analysis also showed that blastocyst transfer was associated with an increased risk of MZT ( OR=0.552, P=0.016, 95% CI: 0.341-0.894). Analysis of blastocyst cycles showed that the risk of MZT was higher when transferring high-quality blastocysts [79.6% (223/280) vs. 67.8% (903/1 332), P<0.001], where as a trophectoderm (TE) grading of C [20.4% (57/280) vs. 32.2% (429/1 332), P<0.001] had a lower risk of MZT. After adjusting for confounding factors, the risk of MZT was found to increase with the transfer of blastocysts with a B-grade inner cell mass (ICM) ( OR=0.601, P=0.001, 95% CI: 0.442-0.819) and A/B grade TE (grade A: OR=2.951, P<0.001, 95% CI: 1.980-4.399; grade B: OR=1.840, P<0.001, 95% CI: 1.315-2.576). The risk of complications during pregnancy [47.7% (143/300) vs. 19.3% (289/1 500), P<0.001], preterm labor [55.1% (140/254) vs. 7.4% (101/1 368), P<0.001], and the risk of stillbirth [3.7% (11/300) vs. 1.5% (22/1 500), P=0.016] were significantly higher in the MZT pregnancy group than in the singleton pregnancy group. Conclusion:Assisted reproductive technology may contribute to the risk of MZT. Transfer of blastocysts, particularly those with loose ICM arrangement and dense TE arrangement, appears to increase the risk of MZT in patients undergoing eSET.

Objective To compare the effects of different doses of budesonide and formoterol fumarate powder for inhalation combined with montelukast sodium tablet in the treatment of cough variant asthma(CVA)and the improvement of airway function and inflammatory factors.Methods Elderly patients with cough variant asthma were randomly divided into group A and group B.Both groups of patients received budesonide and formoterol fumarate powder for inhalation combined with montelukast sodium tablet.Group A was given budesonide and formoterol fumarate powder for inhalation(Ⅱ),2 inhalation per time,twice a day;Group B was given budesonide and formoterol fumarate powder for inhalation,4 inhalation per time,twice a day;budesonide fumatrol inhalation powder mist for continuous treatment for 6 months,and montelukast sodium tablet 10 mg once a day for at least 3 months.The nighttime cough scores of the two groups were compared before treatment and after treatment.The percentage of forced expiratory volume in one second(FEV1)in the predicted value,the maximum mid expiratory flow(MMEF),the fractional exhaled nitric oxide(FeNO),interleukin-5(IL-5)and eosinophils were compared between the two groups.The incidence of adverse drug reactions and the recurrence rate within 1 year were compared between the two groups.Results A total of 45 cases were enrolled in both the group A and the group B.At 9 months after treatment,the nocturnal cough scores of the group A and the group B were(0.93±0.42)and(0.65±0.29)points,respectively;the percentage of FEV1 in the predicted value were(97.75±9.67)％and(100.93±11.06)％,respectively;the MMEF values were(2.81±1.04)and(3.08±1.09)L·s-1,respectively;the FeNO values were(18.94±9.75)and(15.94±7.96)ppb,respectively;the IL-5 levels were(10.88±7.06)and(8.11±5.56)pg·mL-1,respectively.The above indicators in group B showed statistically significant differences compared to group A(all P＜0.05).The total incidence of adverse drug reactions in group A and group B were 8.89％(5 cases/45 cases)and 13.33％(6 cases/45 cases),respectively.The recurrence rates was 15.56％(7 cases/45 cases)and 13.33％(6 cases/45 cases),respectively.There was no statistically significant difference in the above indicators between group B and group A(all P＞0.05).Conclusion For elderly patients with CVA,higher dose of budesonide and formoterol fumarate powder for inhalation combined with montelukast sodium tablet can better improve cough symptoms,reduce the level of airway hyperresponsiveness and inflammatory factors,reduce the recurrence rate,and the patients are well tolerated.

Objective:To observe the clinical efficacy of the modified crowbar-assisted minimally invasive Chevron osteotomy for the treatment of hallux valgus.Methods:A total of 42 patients with hallux valgus who underwent modified crowbar-assisted minimally invasive Chevron osteotomy at Huashan Hospital of Fudan University for hallux valgus from January 2019 to July 2022 were retrospectively analyzed. There were 3 males and 39 females, aged 42.3±8.7 years (range, 26-60 years); 18 left-sided and 24 right-sided, with body mass index 22.9±2.3 kg/m 2. According to the size of the hallux valgus angle (HVA), 26 patients were divided into the mild group (15°≤HVA<20°) and 16 patients were divided into moderate group (20°≤HVA≤40°). All patients were treated with modified crowbar-assisted Chevron osteotomy. The preoperative and postoperative HVA, intermetatarsal angle (IMA), distal metatarsal articular angle (DMAA), visual analogue scale (VAS) and American Orthopaedic Foot and Ankle Society metatarsophalangeal interphalangeal scale (AOFAS Hallux MTP-IP scale) were compared. Results:All patients successfully completed the operation and were followed up for an average of 22.3±6.5 months (range, 18-30 months). The HVA, IMA, and DMAA in the mild group at the last follow-up were 6.6°±1.8°, 8.1°±1.8°, and 4.3°±1.1°, respectively, which were significantly lower than those before operation 17.8°±1.4°, 12.5°±1.5°, and 7.6°±2.4° ( P<0.05). The HVA, IMA, and DMAA in the moderate group at the last follow-up were 7.6°±2.1°, 8.8°±1.6°, and 4.8°±2.9°, respectively, which were significantly lower than those before operation 32.3°±3.5°, 14.8°±3.5°, and 12.7°±5.4° ( P<0.05). At the last follow-up, there was no significant difference in HVA, IMA, or DMAA between the two groups ( P>0.05). The differences of HVA, IMA, and DMAA before and after operation in the moderate group were 24.7°±2.6°, 6.0°±2.3°, and 7.9°±3.8°, respectively, which were greater than those in the mild group 11.2°±1.7°, 4.4°±1.6°, and 3.3°±1.6°, and the differences were statistically significant ( P<0.05). At the last follow-up, the VAS score of the mild group decreased from 2.6±2.0 before surgery to 0.4±0.2, and the difference was statistically significant ( t=6.014, P<0.001). The VAS score of the moderate group decreased from 3.2±2.2 before surgery to 0.4±0.3, the difference was statistically significant ( t=8.777, P<0.001). The preoperative AOFAS Hallux MTP-IP scale of the toe metatarsal joint in the mild group and the moderate group were 71.6±5.9 and 64.3±7.8, respectively, which increased to 93.3±6.0 and 92.3±6.0 at the last follow-up, and the difference was statistically significant ( P<0.05). At the last follow-up, there was no significant difference in AOFAS Hallux MTP-IP scale between the two groups ( P>0.05). Twenty-two of the 26 patients in the mild group were satisfied, and 14 of the 16 patients in the moderate group were satisfied, and the difference in satisfaction between the two groups was not statistically significant ( P>0.05). Conclusion:The clinical efficacy of the modified crowbar-assisted minimally invasive Chevron osteotomy in the treatment of hallux valgus is satisfactory, and it can effectively correct the hallux valgus deformity and improve the function of the metatarsophalangeal joint.

Objective:To explore the safety and efficacy of intraosseous regional administration (IORA) of vancomycin for preventing infection in primary total knee arthroplasty (TKA).Methods:A total of 124 patients with knee osteoarthritis undergoing TKA between February 2024 and May 2024 at nine hospitals were enrolled. Preoperative infection prophylaxis involved either IORA (0.5 g vancomycin administered via intraosseous regional infusion before incision) or intravenous infusion (1 g vancomycin via peripheral vein). The IORA group included 15 males and 47 females with a median age of 66.5 years (range, 60.0-70.0 years), while the intravenous group included 14 males and 48 females with a median age of 66.0 years (range, 61.8-70.3 years) years. Intraoperative samples were collected including fat and synovium tissues after incision, before prosthesis placement, and after tourniquet release; distal femoral cancellous bone during femoral osteotomy; proximal tibial cancellous bone during tibial osteotomy; proximal intercondylar cancellous bone before prosthesis placement; and peripheral blood from non-infused arms at surgery initiation and after tourniquet release. Vancomycin concentrations were measured using liquid chromatography-tandem mass spectrometry. Vital sign changes were recorded from admission to 5~10 minutes post-IORA (IORA group) or post-incision (intravenous group). Follow-ups were conducted on postoperative day 1 and 3, and at 1 and 3 months, to document complications including IORA-related adverse events, periprosthetic joint infections, surgical site infections, red man syndrome, acute kidney injury, deep vein thrombosis and so on.Results:Vancomycin concentrations in bone, fat, and synovial tissue samples were significantly higher in the IORA group than in the intravenous group ( P<0.05), while vancomycin concentrations in blood samples were significantly lower in the IORA group than in the intravenous group ( P<0.05). Only 7.3%(41/558) of tissue samples in the IORA group had vancomycin concentrations below 2.0 μg/g (the minimum inhibitory concentration of vancomycin against coagulase-negative staphylococcus), compared to 59.3%(331/558) in the intravenous group (χ 2=11.285, P<0.001). In the intravenous group, 16.9%(21/124) of blood samples had vancomycin concentrations exceeding 15.0 mg/L (the threshold associated with a significantly increased risk of nephrotoxicity), while all concentrations in the IORA group were below this threshold, the difference was statistically significant (χ 2=22.943, P<0.001). There were no statistically significant difference ( P>0.05) in vital signs changes before and after vancomycin administration between the two groups. Two patients in the intravenous group experienced incision exudate, while no other related complications occurred in either group. Conclusions:Compared to the traditional intravenous infusion of 1 g vancomycin, intraosseous injection of a low dose (0.5 g) of vancomycin achieves higher local tissue concentrations in the knee joint with a lower incidence of adverse reactions and is safe for infection prophylaxis. Despite guidelines not recommending the routine use of vancomycin for preventing infection after primary TKA, intraosseous injection of 0.5 g vancomycin may be considered intraoperatively for primary TKA in the following scenarios: patients in medical institutions with a high prevalence of methicillin-resistant staphylococcus aureus (MRSA) infections, patients with potential preoperative MRSA colonization, or patients with cephalosporin allergy.

Objective To investigate the factors influencing global longitudinal strain(GLS)measured by cardiac magnetic resonance(CMR)in patients with acute ST-segment elevation myocardial infarction(STEMI).Methods Clinical data of 315 hospitalized patients diagnosed with acute STEMI who underwent percutaneous coronary intervention(PCI)at the First Medical Center of Chinese PLA General Hospital from June 2016 to September 2021 were retrospectively collected.After analyzing CMR images of all patients,GLS and other strain parameters were obtained,and then the patients were divided into two groups according to the median GLS.In order to balance gender and age differences,1:1 propensity score matching was performed,and 206 patients were eventually included:GLS>-11.3%group(indicating severe GLS impairment,n=103)and GLS≤-11.3%group(n=103).Baseline characteristics,laboratory indicators,coronary angiographic parameters,electrocardiogram(ECG)features,and CMR parameters were compared between the two groups.Variables showing significant differences were analyzed for their correlation with GLS.Multivariate logistic regression and multiple stepwise linear regression analyses were performed to identify factors associated with GLS impairment.Results Compared with GLS≤-11.3%group,GLS>-11.3%group had significantly higher peak levels of creatine kinase-MB(CK-MB)and troponin T(TnT)(P<0.001).A higher proportion of patients in GLS>-11.3%group had the left anterior descending artery(LAD)as the culprit vessel,while a lower proportion had the right coronary artery(RCA)as the culprit vessel(P<0.001).Additionally,GLS>-11.3%group had longer QRS duration(P<0.001)and a higher incidence of pathological Q waves(P=0.001).Regarding CMR parameters,GLS>-11.3%group exhibited larger global circumferential strain(GCS),infarct size(IS),and left ventricular end-systolic volume(LVESV),as well as lower global radial strain(GRS)and left ventricular ejection fraction(LVEF)(P<0.001).Multivariate logistic regression indicated that peak TnT(OR=1.092,P=0.001),LAD culprit vessel(OR=3.744,P<0.001),and QRS duration(OR=1.026,P<0.001)were significantly associated with severely impaired GLS.Multiple stepwise linear regression analysis showed that the logarithmic value of peak TnT,LAD as the culprit vessel,and the square root of QRS duration were linearly correlated with GLS values(adjusted R2=0.301,P<0.001),and these independent variables explained 30.1%of the variation in GLS.Conclusion Elevated peak TnT,prolonged QRS duration,and LAD as the culprit vessel are significantly associated with severe GLS impairment in STEMI patients,indicating more severe myocardial infarction and worse left ventricular function.

Objective:To explore the impact of changes of myocardial infarct size on left ventricular adverse remodeling in patients with acute ST-segment elevation myocardial infarction (STEMI) after primary percutaneous coronary intervention (PCI).Methods:This was a prospective cohort study. The STEMI patients who underwent primary PCI in the First Medical Center of the Chinese People′s Liberation Army General Hospital, Beijing Anzhen Hospital, Hainan Hospital of the Chinese People′s Liberation Army General Hospital and Guangxi Yulin First People Hospital from January 1, 2017 to January 1, 2022 were enrolled. Cardiac magnetic resonance (CMR) was performed to dynamically assess the myocardial infarct size and calculate the rate of infarct size change between the acute phase (5 to 7 days post-primary PCI) and 6-month follow-up. The endpoint was left ventricular adverse remodeling which was defined as an increase of more than 20% in left ventricular end-diastolic volume (LVEDV) assessed by CMR at 6 months after primary PCI compared with LVEDV at 1 week after primary PCI. Based on serial CMR assessments, the patients were divided into left ventricular adverse remodeling group and non-remodeling group. The receiver operating characteristic (ROC) curve was used to evaluate the predictive performance of infarct size change for left ventricular adverse remodeling, and according to the optimal cutoff value, improved infarct size was defined as a decrease of >20% in the infarct size measured by CMR at 6 months after primary PCI compared with infarct size at 1 week after primary PCI. Multivariate logistic regression analysis was performed to identify the protective factors and risk factors for left ventricular adverse remodeling.Results:A total of 267 patients were enrolled, aged (58±11) years, with 234 males (87.6%). And 73 cases in the left ventricular remodeling group and 194 cases in the non-remodeling group. Infarct size assessed by CMR at 6 months after primary PCI decreased significantly compared with infarct size at 1 week after primary PCI in the left ventricular remodeling group ((23±13)% vs. (27±12)%, P=0.004), the same as in the non-remodeling group ((18±10)% vs. (23±10)%, P<0.001). The area under the ROC curve for the rate of infarct size change in predicting left ventricular remodeling was 0.735 (95% CI 0.670-0.799, P<0.001), a 20% reduction was the optimal cut-off value. Compared to the patients with non-improved infarct size, the incidence of left ventricular adverse remodeling was significantly lower in the patients with improved infarct size (18% (24/133) vs. 37% (49/134), P=0.001). Multivariate logistic regression analysis showed that improvement in IS was a protective factor for left ventricular adverse remodeling ( OR=0.376, 95% CI 0.236-0.721, P=0.002). Conclusion:Patients with STEMI who experience obvious reduction in infarct size after primary PCI have a significantly reduced risk of left ventricular adverse remodeling.

Objective:To explore the impact of the two-way referral model on compliance and prognosis in patients with heart failure.Methods:This bidirectional cohort study enrolled chronic heart failure (CHF) patients treated at Qilu Hospital of Shandong University or designated primary hospitals between March 2018 and March 2022. Patients were categorized into two groups based on referral status: two-way referral group (participating in the referral model with≥1 follow-up visit at primary hospitals) and the core hospital group (receiving treatment and follow-up exclusively at Qilu Hospital). Baseline clinical characteristics were collected and compared between groups. Patients underwent followed-up, with primary endpoints including follow-up rate, drug (β-blockers, angiotension converting enzyme inhibitor (ACEI)/angiotensin Ⅱ receptor blockers (ARB)/angiotensin receptor-neprilysin inhibitor (ARNI), sodium-glucose cotransporter 2 inhibitors and mineralocorticoid receptor antagonists) utilization rate and target dose achievement rate. Secondary endpoints encompassed changes from baseline in left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDd), and N-terminal pro-brain natriuretic peptide (NT-proBNP), plus cardiovascular mortality and heart failure rehospitalization. Generalized linear mixed models analyzed longitudinal trends in LVEF, LVEDd, and NT-proBNP levels. Kaplan-Meier curves and Cox regression evaluated LVEF recovery rates, supplemented by subgroup analyses. Multivariate logistic regression was used to identify factors influencing target dose achievement rate for β-blockers and ACEI/ARB/ARNI therapies in CHF patients.Results:A total of 357 patients were enrolled, aged 53 (41, 63) years, including 256 males (71.7%). 157 patients were in the two-way referral group and 200 patients in the core hospital-treated group. Compared with the core hospital-treated group, the two-way referral group had lower baseline LVEF (28 (22, 34)% vs. 31 (23, 36)%, P=0.021) and systolic blood pressure (116 (104, 125) mmHg vs. 121 (109, 134) mmHg (1 mmHg=0.133 kPa), P=0.010). The 12-month follow-up rate of the two-way referral group was higher than the core hospital-treated group (73.8% vs. 56.0%, P=0.004). No significant between-group differences were observed in drug utilization rate of β-blockers, ACEI/ARB/ARNI, or sodium-glucose cotransporter 2 inhibitors during follow-up (all P>0.05), while mineralocorticoid receptor antagonists use showed a declining trend in both groups. Although the core hospital-treated group had higher target dose achievement rates for β-blockers (65.4% vs. 49.3%, P=0.042) and ACEI/ARB/ARNI (79.8% vs. 65.8%, P=0.046) than the two-way referral group, multivariate logistic regression indicated that the two-way referral model was not a negative predictor for these outcomes (all P>0.05). Both groups showed improved NT-proBNP, LVEDd, and LVEF from baseline (all P<0.001) with no significant difference in trends between groups (all P>0.05). There was no significant difference in the composite incidence (7.6% vs. 6.5%, P=0.674) and cumulative incidence (log-rank P=0.684) of cardiovascular death and heart failure rehospitalization at 12 months between two groups. Conclusion:The two-way referral model demonstrates advantages in improving medication adherence, drug utilization rates, and targetdoseachievement rates among CHF patients. This model not only promotes cardiac functional recovery but also reduces risks of cardiovascular mortality and heart failure rehospitalization, achieving comparable therapeutic and management outcomes to those observed in core hospital-treated patients.

Objective:To observe the clinical efficacy of the modified crowbar-assisted minimally invasive Chevron osteotomy for the treatment of hallux valgus.Methods:A total of 42 patients with hallux valgus who underwent modified crowbar-assisted minimally invasive Chevron osteotomy at Huashan Hospital of Fudan University for hallux valgus from January 2019 to July 2022 were retrospectively analyzed. There were 3 males and 39 females, aged 42.3±8.7 years (range, 26-60 years); 18 left-sided and 24 right-sided, with body mass index 22.9±2.3 kg/m 2. According to the size of the hallux valgus angle (HVA), 26 patients were divided into the mild group (15°≤HVA<20°) and 16 patients were divided into moderate group (20°≤HVA≤40°). All patients were treated with modified crowbar-assisted Chevron osteotomy. The preoperative and postoperative HVA, intermetatarsal angle (IMA), distal metatarsal articular angle (DMAA), visual analogue scale (VAS) and American Orthopaedic Foot and Ankle Society metatarsophalangeal interphalangeal scale (AOFAS Hallux MTP-IP scale) were compared. Results:All patients successfully completed the operation and were followed up for an average of 22.3±6.5 months (range, 18-30 months). The HVA, IMA, and DMAA in the mild group at the last follow-up were 6.6°±1.8°, 8.1°±1.8°, and 4.3°±1.1°, respectively, which were significantly lower than those before operation 17.8°±1.4°, 12.5°±1.5°, and 7.6°±2.4° ( P<0.05). The HVA, IMA, and DMAA in the moderate group at the last follow-up were 7.6°±2.1°, 8.8°±1.6°, and 4.8°±2.9°, respectively, which were significantly lower than those before operation 32.3°±3.5°, 14.8°±3.5°, and 12.7°±5.4° ( P<0.05). At the last follow-up, there was no significant difference in HVA, IMA, or DMAA between the two groups ( P>0.05). The differences of HVA, IMA, and DMAA before and after operation in the moderate group were 24.7°±2.6°, 6.0°±2.3°, and 7.9°±3.8°, respectively, which were greater than those in the mild group 11.2°±1.7°, 4.4°±1.6°, and 3.3°±1.6°, and the differences were statistically significant ( P<0.05). At the last follow-up, the VAS score of the mild group decreased from 2.6±2.0 before surgery to 0.4±0.2, and the difference was statistically significant ( t=6.014, P<0.001). The VAS score of the moderate group decreased from 3.2±2.2 before surgery to 0.4±0.3, the difference was statistically significant ( t=8.777, P<0.001). The preoperative AOFAS Hallux MTP-IP scale of the toe metatarsal joint in the mild group and the moderate group were 71.6±5.9 and 64.3±7.8, respectively, which increased to 93.3±6.0 and 92.3±6.0 at the last follow-up, and the difference was statistically significant ( P<0.05). At the last follow-up, there was no significant difference in AOFAS Hallux MTP-IP scale between the two groups ( P>0.05). Twenty-two of the 26 patients in the mild group were satisfied, and 14 of the 16 patients in the moderate group were satisfied, and the difference in satisfaction between the two groups was not statistically significant ( P>0.05). Conclusion:The clinical efficacy of the modified crowbar-assisted minimally invasive Chevron osteotomy in the treatment of hallux valgus is satisfactory, and it can effectively correct the hallux valgus deformity and improve the function of the metatarsophalangeal joint.

Objective:To explore the safety and efficacy of intraosseous regional administration (IORA) of vancomycin for preventing infection in primary total knee arthroplasty (TKA).Methods:A total of 124 patients with knee osteoarthritis undergoing TKA between February 2024 and May 2024 at nine hospitals were enrolled. Preoperative infection prophylaxis involved either IORA (0.5 g vancomycin administered via intraosseous regional infusion before incision) or intravenous infusion (1 g vancomycin via peripheral vein). The IORA group included 15 males and 47 females with a median age of 66.5 years (range, 60.0-70.0 years), while the intravenous group included 14 males and 48 females with a median age of 66.0 years (range, 61.8-70.3 years) years. Intraoperative samples were collected including fat and synovium tissues after incision, before prosthesis placement, and after tourniquet release; distal femoral cancellous bone during femoral osteotomy; proximal tibial cancellous bone during tibial osteotomy; proximal intercondylar cancellous bone before prosthesis placement; and peripheral blood from non-infused arms at surgery initiation and after tourniquet release. Vancomycin concentrations were measured using liquid chromatography-tandem mass spectrometry. Vital sign changes were recorded from admission to 5~10 minutes post-IORA (IORA group) or post-incision (intravenous group). Follow-ups were conducted on postoperative day 1 and 3, and at 1 and 3 months, to document complications including IORA-related adverse events, periprosthetic joint infections, surgical site infections, red man syndrome, acute kidney injury, deep vein thrombosis and so on.Results:Vancomycin concentrations in bone, fat, and synovial tissue samples were significantly higher in the IORA group than in the intravenous group ( P<0.05), while vancomycin concentrations in blood samples were significantly lower in the IORA group than in the intravenous group ( P<0.05). Only 7.3%(41/558) of tissue samples in the IORA group had vancomycin concentrations below 2.0 μg/g (the minimum inhibitory concentration of vancomycin against coagulase-negative staphylococcus), compared to 59.3%(331/558) in the intravenous group (χ 2=11.285, P<0.001). In the intravenous group, 16.9%(21/124) of blood samples had vancomycin concentrations exceeding 15.0 mg/L (the threshold associated with a significantly increased risk of nephrotoxicity), while all concentrations in the IORA group were below this threshold, the difference was statistically significant (χ 2=22.943, P<0.001). There were no statistically significant difference ( P>0.05) in vital signs changes before and after vancomycin administration between the two groups. Two patients in the intravenous group experienced incision exudate, while no other related complications occurred in either group. Conclusions:Compared to the traditional intravenous infusion of 1 g vancomycin, intraosseous injection of a low dose (0.5 g) of vancomycin achieves higher local tissue concentrations in the knee joint with a lower incidence of adverse reactions and is safe for infection prophylaxis. Despite guidelines not recommending the routine use of vancomycin for preventing infection after primary TKA, intraosseous injection of 0.5 g vancomycin may be considered intraoperatively for primary TKA in the following scenarios: patients in medical institutions with a high prevalence of methicillin-resistant staphylococcus aureus (MRSA) infections, patients with potential preoperative MRSA colonization, or patients with cephalosporin allergy.