Objective:To assess if metagenomic next-generation sequencing (mNGS) of periprosthetic joint tissue can provide an alternative rapid and sensitive tool for the diagnosis of prosthetic joint infection (PJI), especially compared to microbiological culture.Methods:A total of 33 eligible patients who underwent revision arthroplasty from June 2019 to June 2020 in orthopedic surgery department of the first affiliated hospital of Zhengzhou University were retrospectively analyzed. Twenty-one patients were included in PJI group according to the American Academy of Musculoskeletal Infection diagnostic criteria, with 17 cases of knee and 4 cases of hip, including 9 cases of male and 12 cases of female, with an average age of 59.14±14.55 years old (range from 28 to 84), and an average BMI of 23.7±2.8 kg/m 2 (range from 17.7 to 29.4 kg/m 2). Twelve patients were included in aseptic loosening group (control group), with 4 cases of knee and 8 cases of hip, including 4 cases of male and 8 cases of female, with an average age of 53.08±10.05 years old (range from 39 to 70), and an average BMI of 25.2±2.9 kg/m 2 (range from 18.3 to 31.2 kg/m 2 ). Microbiological culture results of synovial fluid and periprosthetic joint tissue and mNGS results of periprosthetic joint tissue were collected. The sensitivity and specificity of mNGS and microbiological culture were calculated and compared. The species of pathogenic microorganismsdetected by the two techniques were summarized. In addition, the impact of antibiotic use on the efficacy of both techniques were compared. Results:mNGS detected 13 positive cases and microbiological culture detected 6 positive cases in the PJI group. In the aseptic loosening group, 1 case was determined positive by mNGS, and all the microbiological culture results were negative. In the diagnosis of PJI, mNGS showed significantly higher sensitivity than that of culture (61.9% vs 28.6%, χ2=4.71, P=0.03), while no statistical difference was observed in terms of specificity (91.7% vs 100%, χ2=1.04, P=0.31). In the PJI cases with prior exposure to antibiotics within two weeks, the sensitivity of mNGS was significantly higher than that of culture (53.8% vs 15.4%, χ2=4.25, P=0.04). However, there was no significant difference in the sensitivity between mNGS and culture in patients without antibioticsexposure (66.7% vs 44.4%, χ2=0.90, P=0.34). In the detection of pathogenic microorganism, mNGS detected 9 kinds of bacteria (Staphylococcus aureus, Staphylococcus family, Moraxella Oslo, Propionibacterium acnes, Streptococcus acnes, Staphylococcus epidermidis, Mycobacterium tuberculosis, Staphylococcus Lyons, Bacteroides fragilis) and 2 kinds of fungi (Aspergillus fumigatus, Candida parapsilosis), while microbiological culture detected 3 kinds of bacteria (Staphylococcus aureus, Moraxella catarrhalis, Mycobacterium tuberculosis) and one kind of fungi (Candida parapsilosis). mNGS and microbiological culture were both positive in 5 cases, among which 3 cases had completely matched results (Staphylococcus aureus, Mycobacterium tuberculosis, Candida parapsilosis), one case had partly matched results (mNGS detected more bacteria than culture) and one case had totally mismatched results. Additionally, in the diagnosis of the 3 included tuberculous PJI, mNGS showed 100% specificity and sensitivity. Conclusion:mNGS of periprosthetic joint tissue is a more powerful tool for diagnosis and pathogen detection of PJI compared to microbiological culture, especially in the diagnosis of tuberculosis PJI. Besides, mNGS is more resistant to antibiotic exposure than culture.

Objective:To investigate the factors for and prevention of muscular calf vein thrombosis (MCVT) after unilateral total knee arthroplasty (TKA).Methods:Between January 2018 and October 2020, 551 patients were admitted to Department of Orthopedics, The First Affiliated Hospital to Zhengzhou University for unilateral TKA. They were 187 males and 364 females, aged from 32 to 90 years (average, 64.6 years) and with 234 left and 317 right knees affected. They were assigned into a MCVT group ( n=77) and a non-MCVT group ( n=474) according to whether or not MCVT had happened at 7 days after operation. Recorded were the patients’ baseline information, tourniquet time, intraoperative blood loss, postoperative prothrombin time (PT), postoperative thrombin time (TT), postoperative fibrinogen (FIB), D-dimer, platelet count (PLT), postoperative bed time, knee society score (KSS), erythrocyte sedimentation rate (ESR) fall time, and C-reactive protein (CRP) fall time so as to analyze the risk factors for MCVT. Results:There were significant differences between the 2 groups in age [(66.8±7.0) versus (64.2±9.6) years], body mass index (BMI) [(28.7±2.2) versus (25.0±2.4) kg/m 2], smoking (20/57 versus 41/433), diabetes (56/21 versus 172/302), primary hypertension (45/32 versus 174/300), coronary heart disease (50/27 versus204/270), hyperlipidemia (33/44 versus 149/325), varicosity (50/27 versus 166/308), tourniquet time [(97.9±22.6) versus (83.1±10.6) min], intraoperative blood loss [(73.2±40.6) versus (62.4±11.5) mL], postoperative PT [(10.7±0.8) versus (11.9±1.0) s], TT [(15.2±1.3) versus (17.2±2.4) s], FIB [(3.7±0.8) versus (3.2±0.5) g/L], D-dimer [(1.1±1.0) versus (0.8±0.3) μg/L], PLT [(233.4±68.5) versus (178.5±27.8) 10 9/L], postoperative bed time [(17.3±2.6) versus (14.6±3.8) h], KSS [(3.32±0.7) versus (3.61±0.56) points], ESR fall time [(2.90±0.74) versus (1.55±0.64) d] and CRP fall time [(2.90±0.74) versus (1.55±0.64) d] (all P<0.05). Multivariate logistic regression analysis showed that old age (95% CI: 0.890 to 1.112, P=0.034), high BMI (95% CI: 1.012 to 1.214, P=0.046), diabetes (95% CI: 1.002 to 2.590, P=0.020), D-dimer (95% CI: 1.239 to 10.292, P=0.001) and postoperative PLT (95% CI: 1.012 to 1.112, P=0.014) were independent risk factors for MCVT. Reduced postoperative bed time (95% CI: 1.009 to 1.469, P=0.040) was a protective factor. Conclusions:As old age, high BMI, diabetes, and high postoperative levels of D-dimer and PLT may be independent risk factors for MCVT, patients with such characteristics should be alert to MCVT. Early ambulation should be encouraged in patients after unilateral TKA to reduce postoperative bed time for prevention of the disease.

ObjectiveTo explore the improving effects and its synergistic mechanism of Olibanum before and after processing with vinegar on glycodesoxycholic acid（GDCA） intervention in mice with ulcerative colitis（UC） based on the perspective of intestinal flora. MethodC57BL/6J male mice were randomly divided into the normal group， model group， GDCA group， Olibanum group（1.5 g·kg^-1） and vinegar-processed Olibanum（1.5 g·kg^-1） group， with 6 mice in each group. Mice in the normal group drank water freely， and mice in the other groups were given 2% dextran sulfate sodium（DSS） periodically to establish a UC mouse model. During the modeling， GDCA group， Olibanum group and vinegar-processed Olibanum group were intervened by intraperitoneally injection of GDCA（0.05 g·kg^-1）. From the 13^th day after modeling， Olibanum group and vinegar-processed Olibanum group were given the corresponding doses of drugs by gavage， once a day， for 36 d. During this period， the body mass of mice was recorded and the disease activity index（DAI） was assessed. On day 48， faeces were collected for 16S rRNA and metagenomic sequencing to analyse changes in intestinal flora. On the 49^th day， hematoxylin-eosion（HE） staining was used to observe the colon histological lesions， enzyme-linked immunosorbent assay（ELISA） was used to determine serum levels of tumour necrosis factor-α（TNF-α）， interleukin（IL）-1β and IL-6， and Spearman correlation analysis was used to explore the correlation between differential bacterial species and inflammatory factor levels. ResultCompared with the normal group， the model group showed a significant decrease in body weight（P<0.01）， a significant increase in DAI（P<0.05）， and a significant increase in TNF-α， IL-1β and IL-6 levels（P<0.01）， and there was partial infiltration of inflammatory cells in the colon. Compared with the model group， mice in the GDCA group showed a significant decrease in body weight， a significant increase in DAI and levels of TNF-α， IL-1β and IL-6（P<0.01）， and severe disruption of colonic crypt structure， extensive infiltration of inflammatory cells， and a significant decrease in goblet cells. Compared with the GDCA group， both the Olibanum and vinegar-processed Olibanum groups showed a significant recovery in body weight， a significant decrease in DAI and levels of TNF-α， IL-6 and IL-1β（P<0.05， P<0.01）， and the modulating effect of vinegar-processed Olibanum was significantly better than that of Olibanum. Alpha diversity showed that Chao1 index of UC mice significantly increased（P<0.01） and Shannon index decreased significantly（P<0.05） in UC mice after GDCA intervention. Beta diversity showed that the microbial community structure of the 5 groups had significant changes， Olibanum and vinegar-processed Olibanum could modulate the changes in the structure of the intestinal flora in UC mice after GDCA intervention. Microbial sequencing results indicated that， compared with the normal group， the Firmicutes/Bacteroidetes ratio in the model group was significantly higher（P<0.05）， and the relative abundance of 3 genera and 5 species of flora changed significantly（P<0.05， P<0.01）. Compared with the model group， the Firmicutes/Bacteroidetes ratio in the GDCA group was significantly higher（P<0.05）， the relative abundance of 7 pathogenic bacterial genera and four species was significantly increased（P<0.05， P<0.01）， and the relative abundance of three beneficial bacterial genera and Bacteroides_intestinalis was significantly decreased（P<0.05， P<0.01）. Olibanum group and vinegar-processed Olibanum group could modulate the Firmicutes/Bacteroidetes ratio， the relative abundance of pathogenic bacteria and beneficial bacteria， and the vinegar-processed Olibanum group was significantly superior to Olibanum group in terms of modulating the Firmicutes/Bacteroidetes ratio， the relative abundance of the three genera and five species of bacteria（P<0.01， P<0.05）. Correlation analysis showed that the relative abundance of Bacteroides_intestinalis was negatively correlated with the levels of TNF-α， IL-6 and IL-1β， the relative abundance of Prevotella_sp_CAG873， Bacteroides_sp_CAG927， Bacteroidales_bacterium_52_46 and Bacteroidales_bacterium was positively correlated with TNF-α， IL-6 and IL-1β levels. ConclusionGDCA can exacerbate UC colonic inflammation， and Olibanum and vinegar-processed Olibanum have an ameliorative effect on GDCA-mediated UC， with the vinegar-processed Olibanum showing a stronger ameliorative effect， the mechanism may be related to the regulation the abundance and structure of intestinal beneficial and pathogenic bacteria， and the reduction of inflammatory factor levels.