BACKGROUND:Periprosthetic joint infection is the most common cause of early failure after total knee replacement.The current methods of preventing periprosthetic joint infection by improving the surface of the prosthesis have limitations to varying degrees.OBJECTIVE:To construct a coating material that can stably improve the surface of the implant,prevent the initial floating bacterial infection of periprosthetic infection,and regulate the bone transfer function around the implant.METHODS:(1)Material preparation:YGF polypeptide(which promotes bone formation),LL-37 polypeptide(with antibacterial properties)and YGF+LL-37 composite peptide were prepared by Fmoc solid phase peptide synthesis technology.The titanium-based materials were immersed in the three polypeptide solutions for 2 hours to obtain YGF coating,LL-37 coating and composite peptide coating coated titanium sheets.(2)In vitro experiment:Uncoated titanium sheets and coated titanium sheets were co-cultured with Escherichia coli(or Staphylococcus aureus)and the colonies were counted by plate method.MC3T3 cells were inoculated on the surface of uncoated titanium sheet and coated titanium sheet,respectively.Alizarin red staining was used to observe the calcium salt deposition on the surface of the material.Western blot assay was used to detect the protein expression of RUNX2,osteocalcin,osteopontin,and bone morphogenetic protein 2.(3)Animal experiment:24 SD rats were randomly divided into three groups:the blank group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal;the control group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension;the experimental group(n=8)was implanted with composite peptide coated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension.After 5 weeks of implantation,micro-CT examination,hematoxylin-eosin staining and immunohistochemical staining of femur specimens were performed.RESULTS AND CONCLUSION:(1)In vitro experiment:Compared with uncoated titanium sheet and YGF coated titanium sheet,LL-37 coated and composite peptide coated titanium sheet could significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus.Compared with uncoated titanium sheets and LL-37-coated titanium sheets,YGF-coated and composite peptide-coated titanium sheets could promote calcium salt deposition in osteoblasts and increase the protein expression of RUNX2,osteocalcin,osteopontin and bone morphogenetic protein 2.(2)Animal experiment:Micro-CT test showed that the control group had less bone mass than the blank group and the experimental group.Hematoxylin-eosin staining showed that there was a large amount of fibrous tissue around the nail channel in the control group,only a small amount of tissue fibrosis around the nail channel in the blank group,and only a small amount of tissue fibrosis around the nail channel in the experimental group.Immunohistochemical staining showed that the protein expression of interleukin 1β and tumor necrosis factor α in the control group was higher than that in the blank group and the experimental group,and the expression of osteocalcin,RUNX2 and osteopontin in the experimental group was higher than that in the blank group and the control group.(3)The results show that the titanium-based material coated with YGF+LL-37 composite peptide coating has good antibacterial ability and can promote bone transfer around the implant.

OBJECTIVE:Based on different algorithms of machine learning,the prediction model of lumbar disc herniation has become a trend and hot spot in the development of precision medicine.However,there is limited evidence on the reporting quality and methodological quality of prediction models of lumbar disc herniation outcomes using machine learning.This article is aimed to explore the performance of machine learning algorithms in predicting the prognosis of lumbar disc herniation by comprehensively analyzing the report quality and risk of bias of previous studies that developed and validated prognosis prediction models based on machine learning through a comprehensive literature search,in order to explore the performance of machine learning algorithms in predicting the prognosis of lumbar disc herniation.METHODS:The databases of CNKI,WanFang,VIP,SinOMED,PubMed,Web of Science,Embase,and The Cochrane Library were searched by computer.Studies on the use of machine learning to develop(and/or validate)prognostic prediction models for lumbar disc herniation were collected from the inception of the database to December 31,2023.Two researchers independently screened the literature,extracted data,and assessed the risk of bias of the included studies.The reporting quality and risk of bias of the included studies were assessed by the Multivariable Transparent Reporting of Predictive Models(TRIPOD)statement and the Predictive Model Risk of Bias Assessment Tool(PROBAST).The results of the evaluation were analyzed using descriptive statistics and visual charts.RESULTS:(1)A total of 23 articles were included,and the TRIPOD compliance of each study ranged from 11％to 87％,with a median compliance of 54％.The quality of reporting of titles,detailed descriptions of treatment measures,blinding of predictors,handling of missing data,details of risk stratification,specific procedures for enrollment,model interpretation,and model performance was mostly poor,with TRIPOD adherence rates ranging from 4％to 35％.(2)Of all included studies,61％had a high risk of bias and 39％had an unclear overall risk of bias.The area under the curve,accuracy,sensitivity and specificity were used to evaluate the performance of the model.The areas under the curve of 20 models were reported,ranging from 0.561 to 0.999.Three models reported the accuracy of the model,ranging from 82.07％to 89.65％.(3)Among all included studies,the statistical analysis domain was most often assessed as having a high risk of bias,mainly due to the small number of valid samples,the selection of predictors based on univariate analysis and the lack of calibration and discrimination assessment of the model in the study.CONCLUSION:These results indicate that machine learning can achieve good predictive ability in the development and validation of prognostic models for lumbar disc herniation.The commonly used algorithms include regression algorithm,support vector machine,decision tree,random forest,artificial neural network,naive Bayes and other algorithms.Reasonable algorithms combined with clinical practice can improve the accuracy of prognosis prediction of lumbar disc herniation.However,the reporting and methodological quality of prognosis prediction models based on machine learning are poor,the prediction performance of different models varies greatly,and the generalization and extrapolation of research models are unclear.There is an urgent need to improve the design,implementation and reporting of such studies.To promote the application of machine learning in the clinical practice of lumbar disc herniation prediction models,it is necessary to comprehensively consider various predictors related to the prognosis of the disease before modeling,and strictly follow the relevant standards of PROBAST tool during modeling.

OBJECTIVE:Based on different algorithms of machine learning,the prediction model of lumbar disc herniation has become a trend and hot spot in the development of precision medicine.However,there is limited evidence on the reporting quality and methodological quality of prediction models of lumbar disc herniation outcomes using machine learning.This article is aimed to explore the performance of machine learning algorithms in predicting the prognosis of lumbar disc herniation by comprehensively analyzing the report quality and risk of bias of previous studies that developed and validated prognosis prediction models based on machine learning through a comprehensive literature search,in order to explore the performance of machine learning algorithms in predicting the prognosis of lumbar disc herniation.METHODS:The databases of CNKI,WanFang,VIP,SinOMED,PubMed,Web of Science,Embase,and The Cochrane Library were searched by computer.Studies on the use of machine learning to develop(and/or validate)prognostic prediction models for lumbar disc herniation were collected from the inception of the database to December 31,2023.Two researchers independently screened the literature,extracted data,and assessed the risk of bias of the included studies.The reporting quality and risk of bias of the included studies were assessed by the Multivariable Transparent Reporting of Predictive Models(TRIPOD)statement and the Predictive Model Risk of Bias Assessment Tool(PROBAST).The results of the evaluation were analyzed using descriptive statistics and visual charts.RESULTS:(1)A total of 23 articles were included,and the TRIPOD compliance of each study ranged from 11％to 87％,with a median compliance of 54％.The quality of reporting of titles,detailed descriptions of treatment measures,blinding of predictors,handling of missing data,details of risk stratification,specific procedures for enrollment,model interpretation,and model performance was mostly poor,with TRIPOD adherence rates ranging from 4％to 35％.(2)Of all included studies,61％had a high risk of bias and 39％had an unclear overall risk of bias.The area under the curve,accuracy,sensitivity and specificity were used to evaluate the performance of the model.The areas under the curve of 20 models were reported,ranging from 0.561 to 0.999.Three models reported the accuracy of the model,ranging from 82.07％to 89.65％.(3)Among all included studies,the statistical analysis domain was most often assessed as having a high risk of bias,mainly due to the small number of valid samples,the selection of predictors based on univariate analysis and the lack of calibration and discrimination assessment of the model in the study.CONCLUSION:These results indicate that machine learning can achieve good predictive ability in the development and validation of prognostic models for lumbar disc herniation.The commonly used algorithms include regression algorithm,support vector machine,decision tree,random forest,artificial neural network,naive Bayes and other algorithms.Reasonable algorithms combined with clinical practice can improve the accuracy of prognosis prediction of lumbar disc herniation.However,the reporting and methodological quality of prognosis prediction models based on machine learning are poor,the prediction performance of different models varies greatly,and the generalization and extrapolation of research models are unclear.There is an urgent need to improve the design,implementation and reporting of such studies.To promote the application of machine learning in the clinical practice of lumbar disc herniation prediction models,it is necessary to comprehensively consider various predictors related to the prognosis of the disease before modeling,and strictly follow the relevant standards of PROBAST tool during modeling.

BACKGROUND:Periprosthetic joint infection is the most common cause of early failure after total knee replacement.The current methods of preventing periprosthetic joint infection by improving the surface of the prosthesis have limitations to varying degrees.OBJECTIVE:To construct a coating material that can stably improve the surface of the implant,prevent the initial floating bacterial infection of periprosthetic infection,and regulate the bone transfer function around the implant.METHODS:(1)Material preparation:YGF polypeptide(which promotes bone formation),LL-37 polypeptide(with antibacterial properties)and YGF+LL-37 composite peptide were prepared by Fmoc solid phase peptide synthesis technology.The titanium-based materials were immersed in the three polypeptide solutions for 2 hours to obtain YGF coating,LL-37 coating and composite peptide coating coated titanium sheets.(2)In vitro experiment:Uncoated titanium sheets and coated titanium sheets were co-cultured with Escherichia coli(or Staphylococcus aureus)and the colonies were counted by plate method.MC3T3 cells were inoculated on the surface of uncoated titanium sheet and coated titanium sheet,respectively.Alizarin red staining was used to observe the calcium salt deposition on the surface of the material.Western blot assay was used to detect the protein expression of RUNX2,osteocalcin,osteopontin,and bone morphogenetic protein 2.(3)Animal experiment:24 SD rats were randomly divided into three groups:the blank group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal;the control group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension;the experimental group(n=8)was implanted with composite peptide coated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension.After 5 weeks of implantation,micro-CT examination,hematoxylin-eosin staining and immunohistochemical staining of femur specimens were performed.RESULTS AND CONCLUSION:(1)In vitro experiment:Compared with uncoated titanium sheet and YGF coated titanium sheet,LL-37 coated and composite peptide coated titanium sheet could significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus.Compared with uncoated titanium sheets and LL-37-coated titanium sheets,YGF-coated and composite peptide-coated titanium sheets could promote calcium salt deposition in osteoblasts and increase the protein expression of RUNX2,osteocalcin,osteopontin and bone morphogenetic protein 2.(2)Animal experiment:Micro-CT test showed that the control group had less bone mass than the blank group and the experimental group.Hematoxylin-eosin staining showed that there was a large amount of fibrous tissue around the nail channel in the control group,only a small amount of tissue fibrosis around the nail channel in the blank group,and only a small amount of tissue fibrosis around the nail channel in the experimental group.Immunohistochemical staining showed that the protein expression of interleukin 1β and tumor necrosis factor α in the control group was higher than that in the blank group and the experimental group,and the expression of osteocalcin,RUNX2 and osteopontin in the experimental group was higher than that in the blank group and the control group.(3)The results show that the titanium-based material coated with YGF+LL-37 composite peptide coating has good antibacterial ability and can promote bone transfer around the implant.

BACKGROUND: The available evidence regarding the benefits of percutaneous coronary intervention (PCI) on patients receiving dialysis with coronary artery disease (CAD) is limited and inconsistent. This study aimed to evaluate the association between PCI and clinical outcomes as compared with medical therapy alone in patients undergoing dialysis with CAD in China. METHODS: This multicenter, retrospective study was conducted in 30 tertiary medical centers across 12 provinces in China from January 2015 to June 2021 to include patients on dialysis with CAD. The primary outcome was major adverse cardiovascular events (MACE), defined as a composite of cardiovascular death, non-fatal myocardial infarction, and non-fatal stroke. Secondary outcomes included all-cause death, the individual components of MACE, and Bleeding Academic Research Consortium criteria types 2, 3, or 5 bleeding. Multivariable Cox proportional hazard models were used to assess the association between PCI and outcomes. Inverse probability of treatment weighting (IPTW) and propensity score matching (PSM) were performed to account for potential between-group differences. RESULTS: Of the 1146 patients on dialysis with significant CAD, 821 (71.6%) underwent PCI. After a median follow-up of 23.0 months, PCI was associated with a 43.0% significantly lower risk for MACE (33.9% [ n  = 278] vs . 43.7% [ n  = 142]; adjusted hazards ratio 0.57, 95% confidence interval 0.45-0.71), along with a slightly increased risk for bleeding outcomes that did not reach statistical significance (11.1% vs . 8.3%; adjusted hazards ratio 1.31, 95% confidence interval, 0.82-2.11). Furthermore, PCI was associated with a significant reduction in all-cause and cardiovascular mortalities. Subgroup analysis did not modify the association of PCI with patient outcomes. These primary findings were consistent across IPTW, PSM, and competing risk analyses. CONCLUSION This study indicated that PCI in patients on dialysis with CAD was significantly associated with lower MACE and mortality when comparing with those with medical therapy alone, albeit with a slightly increased risk for bleeding events that did not reach statistical significance.
Humans ; Percutaneous Coronary Intervention/methods* ; Male ; Female ; Coronary Artery Disease/drug therapy* ; Retrospective Studies ; Renal Dialysis/methods* ; Middle Aged ; Aged ; China ; Proportional Hazards Models ; Treatment Outcome

BACKGROUND: Fibrosis of the connective tissue in the vaginal wall predominates in pelvic organ prolapse (POP), which is characterized by excessive fibroblast-to-myofibroblast differentiation and abnormal deposition of the extracellular matrix (ECM). Our study aimed to investigate the effect of ECM stiffness on vaginal fibroblasts and to explore the role of methyltransferase 3 (METTL3) in the development of POP. METHODS: Polyacrylamide hydrogels were applied to create an ECM microenvironment with variable stiffness to evaluate the effects of ECM stiffness on the proliferation, differentiation, and expression of ECM components in vaginal fibroblasts. METTL3 small interfering RNA and an overexpression vector were transfected into vaginal fibroblasts to evaluate the effects of METTL3 silencing and overexpression on matrix stiffness-induced vaginal fibroblast-to-myofibroblast differentiation and abnormal modulation of the ECM. Both procedures were detected by 5-ethynyl-2'-deoxyuridine (EdU) staining, Western blotting (WB), quantitative real-time polymerase chain reaction (RT-qPCR), and immunofluorescence (IF). RESULTS: Vaginal fibroblasts from POP patients exhibited increased proliferation ability, increased expression of α-smooth muscle actin (α-SMA), decreased expression of collagen I/III, and significantly decreased expression of tissue inhibitors of matrix metalloproteinases (TIMPs) in the stiff matrix ( P <0.05). Compared with those from non-POP patients, vaginal wall tissues from POP patients demonstrated a significant increase in METTL3 content ( P <0.05). However, silencing METTL3 expression in vaginal fibroblasts with high ECM stiffness resulted in decreased proliferation ability, decreased α-SMA expression, an increased ratio of collagen I/III, and increased TIMP1 and TIMP2 expression. Conversely, METTL3 overexpression significantly promoted the process of increased proliferation ability, increased α-SMA expression, decreased ratio of collagen I/III and decreased TIMP1 and TIMP2 expression in the soft matrix ( P <0.05). CONCLUSIONS Elevated ECM stiffness can promote excessive proliferation, differentiation, and abnormal ECM modulation, and the expression of METTL3 plays an important role in alleviating or aggravating matrix stiffness-induced vaginal fibroblast-to-myofibroblast differentiation and abnormal ECM modulation.
Humans ; Female ; Extracellular Matrix/metabolism* ; Cell Differentiation/genetics* ; Methyltransferases/metabolism* ; Pelvic Organ Prolapse/pathology* ; Fibroblasts/metabolism* ; Myofibroblasts/metabolism* ; Vagina/metabolism* ; Cell Proliferation/physiology* ; Cells, Cultured ; Middle Aged

Objective:To evaluate the efficacy and safety of fecal microbiota transplantation (FMT) for treating functional constipation, analyze the incidence of, and factors that influence, adverse events, and provide scientific evidence for optimizing FMT treatment.Methods:This retrospective, multicenter, single-arm, pre–post real-world study included 1529 patients with functional constipation from four clinical centers. Eligibility criteria comprised meeting the diagnostic criteria for functional constipation, having undergone at least one FMT treatment, complete pre- and post-treatment data available, and age ≥18 years. Patients who had received other interventions affecting gut function within 1 month before treatment and those with severe organic diseases or immune deficiencies were excluded. Applying the above criteria yielded 1529 eligible patients with functional constipation from four medical centers (1405 from the Shanghai Tenth People's Hospital Affiliated to Tongji University, 20 from the Central Hospital of Wuhan, 67 from the Shanxi Bethune Hospital and 37 from the Longgang District People's Hospital of Shenzhen). The study cohort comprised 746 male (48.8%) and 783 female patients (51.2%) of mean age (51.4 ± 17.4) years, mean body mass index (26.4 ± 4.9) kg/m2, and mean duration of disease (15.0 ± 8.3) years. The primary outcomes were the incidence, types, and severity of adverse reactions during treatment, and their impact on patients' quality of life. Secondary outcomes included: (1) the efficacy of FMT in treating constipation. This was assessed based on changes in Patient Assessment of Constipation Symptoms (PAC-SYM) scores, where higher score indicates worse symptom. (2) Subjective satisfaction, evaluated through questionnaires or rating scales, reflecting patients' acceptance of and satisfaction with the treatment, with scores ranging from 1 to 5, where higher scores indicated greater satisfaction. Paired t-tests and Wilcoxon signed-rank tests were used to evaluate changes in symptom scores and biochemical indicators before and after treatment. Logistic regression was performed to analyze factors influencing adverse events, and subgroup analyses to explored differences in efficacy between patient groups.Results:In this cohort of 1529 patients with functional constipation, adverse reactions were primarily mild to moderate (1048/1529,68.5%). They comprised fever in 54 patients (3.5%), dizziness or fatigue in 218 (14.3%), throat discomfort in 806 (52.7%), nausea and vomiting in 166 (10.9%), and abdominal distension or pain in 415 (27.1%). According to multivariate logistic regression analysis, PAC-SYM scores were associated with the rate of adverse reactions, higher scores indicating a lower risk (OR = 0.958, 95% CI: 0.923–0.993, P=0.021). Among the 1529 patients, 274 (17.9%) underwent two or more treatment courses. After one treatment course, the patients' PAC-SYM scores decreased from (37.7 ± 3.2) pre-treatment to (23.7 ± 8.6) (mean difference 14.0 ± 9.1). PAC-SYM scores decreased by (20.7 ± 7.7) after two courses of FMT, and by (19.4 ± 6.3) after three courses. After treatment, 50.7%(775/1529) of patients reported satisfaction scores of ≥4. Adverse reactions impacted satisfaction; specifically, dizziness/fatigue, throat discomfort, and abdominal distension/pain were significantly associated with satisfaction (all P < 0.05). Conclusions:FMT achieved good relief of symptoms of functional constipation and multiple treatment courses have a cumulative effect. Adverse reactions, mainly dizziness/fatigue, throat discomfort, and abdominal distension/pain, had significant negative impacts on patient satisfaction.

Objective:To investigate the related factors for unexpected positive intraoperative cultures (UPC) in patients undergoing aseptic hip revision and the long-term prosthesis survival rate in such patients.Methods:A retrospective cases series analysis was conducted in 397 patients who underwent aseptic hip revision surgery at the Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University from January 2012 to December 2021. There were 225 females and 172 males with an age ( M(IQR)) of 58(23) years (range:21 to 89 years) and a body mass index (BMI) of 25(6) kg/m 2 (range:15 to 39 kg/m 2). Based on the culture results of intraoperative specimens, patients were divided into culture-positive group (32 cases) and culture-negative group (365 cases). The clinical data were analyzed including gender, age, BMI, preoperative C-reactive protein, preoperative erythrocyte sedimentation rate, American Society of Anesthesiologists(ASA) classification, preoperative urinary bacteria, preoperative hypoproteinemia; comorbidities of diabetes mellitus, anemia, chronic obstructive pulmonary disease, cerebral infarction; history of allergy to antibiotics, smoking, drinking, previous prosthetic dislocation, previous surgical intervention; and time from symptom onset to admission, duration of surgery, etc. A univariate analysis was performed by Mann-Whitney U orχ2 test and the independent risk factors were identified by including the independent variables with P<0.20 in the univariate analysis in a logistic regression analysis of dichotomous variables. The study outcomes were defined as :(1) re-surgical treatment for any reason; (2)symptoms of infection such as sinus and incision seepage; (3) persistent excessive hip pain.The Kaplan-Meier survival curve was plotted using the study outcome of any cause as the endpoint event, and the log-rank test was used to compare the 10-year survival rate of the prosthesis in the culture-negative group with that in the culture-positive group. Results:Univariate analysis showed statistically significant differences between the culture-negative and culture-positive groups when comparing gender, BMI, ASA classification, and preoperative urinary bacterial results ( χ2=2.368, P=0.124; χ2=-1.648, P=0.098; χ2=14.128, P=0.003; and χ2=7.384, P=0.007). Logistic regression analysis showed that male, ASA classification Ⅳ, and positive preoperative urinary bacteria were independent risk factors for the development of UPC during aseptic hip revision( OR=2.35,95% CI:1.08 to 5.36, P=0.040; OR=37.32,95% CI:1.80 to 1 810.63, P=0.030; OR=4.11,95% CI:1.40 to 11.12, P=0.012). The follow-up time of the 397 patients included in this study was 70 (134) months (range:12 to 146 months). The Kaplan-Meier survival curves showed that the 10-year survival rates of the prostheses in the culture-negative and culture-positive groups were 95.7% and 75.0%, respectively. There was no statistically significant difference in the 10-year survival rate comparing the two groups ( P=0.661). Conclusions:UPC is more likely to occur in patients undergoing hip revision due to noninfectious factors in those who are male, have positive preoperative urinary bacteria, and have an ASA classification of Ⅳ. Intraoperative specimen culture results (negative or positive) do not affect 10-year prosthesis survival rate after hip revision.

Objective:To investigate the diagnostic efficacy of intraoperative direct sonication in periprosthetic joint infection (PJI).Methods:This is a retrospective case series study. The clinical data of 490 patients with PJI or aseptic prosthesis loosening after hip or knee arthroplasty admitted to the Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University from January 2018 to December 2023 were retrospectively analyzed. There were 209 male cases, 281 female cases, aged ( M(IQR)) 63 (19) years (range: 15 to 89 years). There were 328 cases of PJI (123 cases of traditional sonication, 205 cases of intraoperative direct sonication, and 204 cases had simultaneous intraoperative synovial fluid), and 162 patients of aseptic loosening (89 cases of traditional sonication, 73 cases of intraoperative direct sonication, and 96 cases had simultaneous intraoperative synovial fluid). The method of traditional sonication: the prosthesis components were placed in a sterile container, vortexed for 30 seconds, then placed in an ultrasound bath to sonication (frequency:(40±2) kHz, power density:(0.22±0.04) W/cm2) for 5 minutes, vortexed again for 30 seconds, and the resulting sonicate fluid was extracted for culture. The method of intraoperative direct sonication: during the operation, the surgical area, the prosthesis and the tissues around the prosthesis which were placed in a sterile container were respectively subjected to sonication for 5 minutes using a portable handheld ultrasonic cell disruptor device (frequency: 25 kHz, power density:(0.22±0.04) W/cm2), and the fluids before and after sonication were extracted for culture. The method of intraoperative synovial fluid: during the operation, the joint capsule was incised, and the synovial fluid was extracted under direct vision for culture. The sensitivity, specificity, positive and negative predictive values, Youden index, the effect of preoperative antimicrobial agents on culture results, and culture duration for different culture methods. Receiver operating characteristic (ROC) curves were plotted, and the diagnostic efficacy of these methods for PJI was compared using the χ2 test, the Wilcoxon signed-rank test, and other appropriate statistical methods. Results:The sensitivity of intraoperative direct sonication was significantly higher than that of intraoperative synovial fluid culture (89.8%(184/205) vs.56.9%(116/204), χ2=44.457, P<0.01) and traditional sonication (89.8%(184/205) vs.66.7%(82/123), χ2=121.588, P<0.01). However, its specificity was lower compared to intraoperative synovial fluid (87.5%(64/73) vs. 99.0%(95/96), χ2=9.491, P=0.002). The culture duration for intraoperative direct sonication was shorter than for intraoperative synovial fluid 87.0 (41.8) hours vs. 112.5 (78.5) hours, Z=-5.121, P<0.01) and traditional sonication (87.0 (41.8) hours vs. 119.0 (67.5) hours, Z=-7.119, P<0.01). Gram-positive bacteria (predominantly Staphylococcus aureus and Staphylococcus epidermidis) were the most common isolates across all three culture methods. Furthermore, intraoperative direct sonication was more likely to detect polymicrobial infections compared to traditional sonication (38.6% vs. 2.4%, χ2=37.223, P<0.01) and intraoperative synovial fluid (38.6% vs. 0.9%, χ2=55.527, P<0.01). The ROC curve revealed that the area under the curve of intraoperative direct sonication,intraoperative synovial fluid culture and traditional sonication were 0.886 (95% CI:0.843 to 0.930), 0.779 (95% CI:0.743 to 0.815) and 0.788 (95% CI: 0.736 to 0.839). Conclusions:Compared with intraoperative synovial fluid and traditional sonication, intraoperative direct sonication has excellent sensitivity, the shortest appropriate culture duration for pathogenic bacteria, and it is more likely to diagnose PJI patients with polymicrobial infections, having better diagnostic efficacy in the diagnosis of PJI.

Objective To explore the characteristics of fluid flow within loaded osteons under different boundary conditions.Methods The COMSOL Multiphysics software was used to establish a three-dimensional(3D)finite element model of osteons with different boundary conditions,and the variation rules of pore pressure and flow velocity of osteons under different inner wall pulsating blood pressures and outer wall elastic constraint conditions were analyzed.Results As the pulsatile blood pressure inside the osteon increased from 0 mmHg(1 mmHg=0.133 kPa)to 300 mmHg,the peak pore pressure within the osteon correspondingly increased from 26 kPa to 68 kPa.As the elastic constraint on the outer wall of osteons changed from being completely elastic to completely constrained,the peak pore pressure within osteons increased from 15 kPa to 26 kPa,and the peak flow velocity increased from 0.04 um/s to 0.07 um/s.Conclusions This study reveals the influence laws of changes in boundary conditions such as the pulsatile blood pressure on the inner wall and the elastic constraint on the outer wall of osteons on fluid flow characteristics within loaded osteons.These findings are conducive to a deeper understanding of the mechanical response mechanisms of bone tissues in both physiological and pathological states,and provide an important theoretical basrs for further researches on bone mechanotransduction.