Analysis Of Risk Factors And Diagnostic Indexes Of Periprosthetic Joint Infection After Primary Joint Replacement

Objective:(1)To investigate the risk factors of periprosthetic joint infection after primary joint replacement,construct a line graph prediction model and evaluate the differentiation and consistency of the model.(2)Study C-reactive protein,erythrocyte sedimentation rate,white blood cells,platelets,fibrinogen,albumin,globulin,albumin/globulin,platelet count and mean platelet volume,monocyte/lymphocyte,neutrophil/lymphocyte platelet count/lymphocyte in the diagnosis of PJI,looking for more specific and accurate serum parameters.Methods:(1)Clinical data of patients with primary TJA complicated with PJI admitted to the Department of Joint and Sports Medicine of Affiliated Hospital of Jining Medical College from January 2010 to December 2022 were retrospectively analyzed.Among them,63 cases were diagnosed as PJI(PJI group).Control group was set up according to1:2.A total of 126 patients(non-PJI group)who underwent unilateral joint replacement at the same time and did not develop infection were randomly selected.General data,preoperative and operation-related indicators were collected.Univariate analysis and Logistic regression were used to analyze the risk factors of periprosthetic joint infection after joint replacement.R software was used to build a line graph model for predicting PJI risk after TJA,and calibration curve,decision curve and receiver operating characteristic curve were used to evaluate the prediction effect.(2)Clinical data of patients with primary TJA complicated with aseptic loosening admitted to our department from January 2010 to December 2022 were retrospectively analyzed.Among them,133 cases were diagnosed as AL(AL group).The levels of CRP,ESR,WBC,PC,fibrinogen,GLB,ALB,AGR,PC/m PV,NLR,MLR and PLR in the two groups were statistically analyzed.The sensitivity and specificity of each index were calculated by receiver operating characteristic curve,and Z-test was used.The AUC of biomarkers was compared with that of CRP and ESR to explore more accurate biomarkers for PJI detection.Results:Part I:(1)Univariate analysis showed that there were statistically significant differences between the PJI group and the non-PJI group in preoperative Hb,preoperative CRP,preoperative ESR,length of hospital stay,diabetes,positive urinary sediment leukocyte and positive urinary sediment bacteria(P<0.05).(2)Binary Logistic regression analysis showed that preoperative combination of low Hb,diabetes,positive urinary sediment bacteria and positive urinary sediment leukocyte were independent risk factors for PJI after TJA.(3)The line graph prediction model of PJI was constructed by four risk factors.The area under ROC curve was 0.797(95%CI,0.7323-0.8611),the sensitivity was 87.3%,the specificity was 61.1%,the positive predictive value was 52.9%,and the negative predictive value was 90.6%,with good differentiation.Calibration curve and clinical decision curve show better predictive performance and higher clinical valuePart Two:(1)The levels of CRP,WBC,PC,fibrinogen,GLB,PC/m PV,NLR,MLR and PLR in PJI group were significantly higher than those in AL group,while the levels of ALB and AGR in PJI group were significantly lower than those in AL group,and the difference was statistically significant(P<0.05).(2)The AUC,sensitivity and specificity of each marker were: CRP:0.934,90.5%,88.7%,ESR: 0.859,77.8%,84.2%,BC: 0.604,52.4%,77.4%,PC: 0.712,61.9%,77.4%,fibrinogen: 0.906,85.7%,84.2%,GLB:0.650,61.9%,66.9%,ALB: 0.840,69.8%,84.2%,AGR: 0.793,74.6%,76.7%,PC/m PV: 0.733,82.5%,58.6%,NLR: 0.729,57.1%,84.2%,MLR:0.784,55.6%,86.4%,PLR: 0.800,68.3%,83.5%.(3)The results of bacterial culture showed that 29 cases were positive,including 23 cases of gram-positive bacteria,4 cases of gramnegative bacteria and 2 cases of fungi.The most common pathogen was Staphylococcus aureus in 13 cases(44.8%),including 8 cases of knee joint and 5 cases of hip joint.Staphylococcus epidermidis followed by 5cases(17.2%),including 2 cases of knee joint and 3 cases of hip joint.The results of bacterial culture in 34 patients were negative.Conclusion:(1)The risk factors for periprosthetic infection after primary joint replacement include preoperative low hemoglobin,diabetes,positive urinary sediment leukocyte and positive urinary sediment bacteria.The graph model built based on the above risk factors shows good consistency,differentiation and clinical applicability,which can help clinicians to develop individual treatment plans for patients earlier and more accurately.Therefore,the future work should focus on the risk factors leading to infection in patients with initial joint replacement,and for high-risk patients with combined risk factors,targeted treatment should be taken in advance to reduce the incidence of PJI as much as possible.(2)(1)Compared with other blood markers,CRP still has a high diagnostic value in the diagnosis of periprosthetic infection,but the focus should be on PJI caused by low-virulence pathogens with normal CRP levels.The diagnostic value of fibrinogen is similar to CRP,and it is promising to be a new biomarker for the diagnosis of PJI.ESR,ALB,PLR have good diagnostic value,PC,AGR,PC/m PV,NLR/MLR have moderate diagnostic value,WBC,GLB have poor diagnostic value for PJI.(2)Gram-positive bacteria were the main pathogens of periprosthetic joint infection after joint replacement in our hospital,and Staphylococcus aureus was the most common pathogenic bacteria,followed by Staphylococcus epidermidis.Such bacterial infection should be actively prevented early after surgery.When clinicians encounter such bacterial infection,they should pay attention to it and select sensitive antibiotics to improve the success rate of infection control.