Diagnosis And Treatment Of Periprosthetic Infection And Mechanism Of Osteolysis

Objective: Periprosthetic infection is one of the main reasons for the failure of artificial joint replacement.Once it happens,the result will be catastrophic,which will impose a heavy burden on patients physically,mentally and economically.The management of periprosthetic infection requires early diagnosis,early intervention,symptomatic treatment of pathogenic bacteria and correct treatment.At the same time,the main consequence of periprosthetic infection is bone destruction caused by infection.Therefore,we need to clarify the appropriate methods for diagnosis and treatment of periprosthetic infection.The purpose of this study is to study: 1)the diagnostic methods around joint prosthesis,to evaluate the existing indicators through the most common serological diagnosis and to explore new reliable indicators,and to find the correct pathogens through new diagnostic methods.2)By comparing the mechanism of osteolysis caused by infection and aseptic loosening around joint prosthesis,the way of bone destruction caused by infection was further explored.3)Through retrospective analysis,the role of one-stage revision of cementless surgery in the treatment of periprosthetic infection was evaluated.Methods: 1.Diagnostic study of periprosthetic infection: 1)Detection of serum CRP,ESR,D-dimer,IL-6 and PD-L1 concentrations;2)Joint analysis of CRP,ESR,D-dimer,IL-6 and PD-L1.3)Ultrasound lysate culture of articular prosthesis: the cultures of patients’ articular fluid,tissue and prosthesis lysate were compared,and their sensitivity and specificity were compared;4)the whole genome sequencing by shotgun method.2.Study on the mechanism of periprosthetic infection and aseptic loosening osteolysis: 1)Establishment of osteolytic mice model of titanium particles and Staphylococcus aureus;2)Observation of osteolytic reaction of the two models by microscopic CT,HE staining,osteoclast count and osteoclast expression;3)Observation of the expression of TNF-a,IL-1beta and Th17 cells by immunohistochemistry and immunofluorescence counting.4)The expression of TNF-alpha,IL-1beta,IL-6,RANKL/RANK/OPG,NFATC1 and NF-kappa B in periprosthetictissues of ASL and PJI patients were observed by immunohistochemistry and Western blotting.3.Between 2010 and 2016,126 patients underwent routine single-stage revision with cementless reconstruction with powdered vancomycin or imipenem poured into the medullary cavity and re-implantation of cementless components.For patients with a culturenegative hip,fungal infections,and multidrug-resistant organisms,a direct intra-articular infusion of pathogen-sensitive antibiotics was performed postoperatively.Recurrence of infection and clinical outcomes were evaluated.Result: 1.1 Serological diagnosis of periprosthetic infection: 1)Serum CRP levels in three groups were 14.04mg/L in group A,31.18mg/L in group B and 9.270mg/L in group C.The difference between group A and group B was P<0.05.2)The serum ESR levels of the three groups were 21.18mm/hr in group A,47.67mm/hr in group B and 17.83mm/hr in group C.The difference between group A and group B was less than 0.0001.3)Serum D-dimer levels were 290.5ng/m L in group A,566ng/m L in group B and 146.5ng/m L in group C.The difference between group A and group B was less than 0.01.4)Serum IL-6 levels in the three groups were 4.442pg/m L in group A,18.04pg/m L in group B and 4.85pg/m L in group C.The difference between group A and group B was less than 0.0001.5)Contrast and joint analysis of CRP,ESR,D-dimer and IL-6 indicators: When combined detection of CPR and ESR for PJI,its sensitivity was 80%,specificity was 84%,AUC value was 0.86,positive predictive value was 88%,negative predictive value was 74%,positive natural ratio was 5.0,negative natural ratio was 0.24.When D-dimer and CRP were combined,the sensitivity,specificity,AUC value,positive predictive value,negative predictive value,positive natural ratio and negative natural ratio increased to 84%,75%,0.8,82%,79%,3.4 and 0.21 respectively.When combined with D-dimer and ESR,AUC increased to 0.86,sensitivity 83%,specificity 82%,positive predictive value 86%,negative predictive value 78%,positive natural ratio 4.6,negative natural ratio 0.21.Combined detection of D-dimer with CRP and ESR showed that AUC increased to 0.86,sensitivity to 81%,specificity to 82%,positive predictive value to 85%,negative predictive value to 77%,positive natural ratio to 4.5,negative natural ratio to 0.23.The sensitivity and specificity of IL-6 combined with CRP increased to 88%,95%,AUC 0.92,positive predictive value 97%,negative predictive value 84%,positive natural ratio 17.6 and negative natural ratio 0.13.Combined detection of IL-6 and ESR showed that AUC increased to 0.95,sensitivity 89%,specificity 93%,positive predictive value 95%,negative predictive value 85%,positive natural ratio 12.7,negative natural ratio 0.12.The combined detection of IL-6,CRP and ESR showed that the AUC of PJI was as high as 0.96,the sensitivity was unchanged to 88%,the specificity was 95%,the positive predictive valuewas 97%,the negative predictive value was 84%,the positive natural ratio was 17.6,and the negative natural ratio was 0.13.6)The average value of PD-L1 in ASL group was 25.29pg/m L,and that in PJI group was 46.09.The difference between the two groups was significant(P<0.001).1.2 Sonication of joint prosthesis: 58 of 67 patients were cultured with ultrasound lysate,and the sensitivity was 87%(95%CI,76%-93%).Appropriate amount of synovial fluid was extracted from 32 patients before or during the operation.Among them,18 were cultured positive and the sensitivity was 56%(95%CI,38%-73%).In 67 cases of intraoperative tissue culture,47 cases were positive,and the sensitivity was 70%(95%CI,56%-79%).Fifty-one patients with aseptic loosening underwent ultrasound decomposition.Eight of them were cultured positively.The specificity of ultrasound decomposition solution culture was 84%(95%CI,78%-96%),and 28 patients were cultured in synovial fluid during operation.The specificity of ultrasound decomposition solution culture was 100%(95%CI,88%-100%).Tissue cultures were performed in 51 patients,of which 5 were positive,and the specificity was 90%(95%CI,56%-79%).1.3 Metagenomic shotgun sequencing: A synovial membrane sample of hip and knee joint in revision surgery was analyzed by using Metagenomic shotgun sequencing.Among them,8 patients with periprosthetic infection met IDSA diagnostic criteria,and 3 patients with aseptic loosening.Among 8 patients with periprosthetic infection,4 were positive for bacterial culture,1 for Staphylococcus aureus,1 for Staphylococcus epidermidis and Ralstonia,1 for Brucella and 1 for Enterobacter albicans.Among the 4 patients with periprosthetic infection,3 for pathogenic bacteria were detected by macrogenomic shotgun sequencing,including Dafengold.Bacteria were found in 1 case,Acinetobacter baumannii,Propionibacter acne in 1 case and Ralstonia in 1 case.2.Study on the mechanism of periprosthetic infection and aseptic osteolysis: 2.1 Osteolysis of titanium particles and Staphylococcus aureus in mice model: 1)Microscopic CT analysis of the effect of titanium particles and Staphylococcus aureus on the skull of mice: Measuring the volume of bone in the same volume(BV/TV),the titanium particles implantation group was lower than the sham operation group,and the difference was statistically significant(P < 0).05=Staphylococcus aureus implantation group was higher than sham operation group and the difference was statistically significant(P<0.05),at the same time,the difference between titanium particle implantation group and Staphylococcus aureus implantation group was also significant(P<0.05).Analysis of the skull bonemineral density(BMD)of three groups of mice showed that compared with the sham operation group,the bonemineral density of the titanium particle implantation group and the Staphylococcus aureus implantation group decreased significantly(P<0.05),and the bonemineral density of the titanium particle implantation group was also lower than that of the Staphylococcus aureus implantation group(P < 0.05).Titanium particle implantation group and Staphylococcus aureus implantation group had significantly higher overall bone porosity than normal group(P<0.05,similarly,Titanium particle implantation group had higher porosity than Staphylococcus aureus implantation group(P<0.05);2)HE staining analysis of the effects of Titanium particles and Staphylococcus aureus on the skull of mice: skull surface erosion rate,Titanium particle implantation group and Staphylococcus aureus compared with An.There were significant differences between the placebo group and the placebo group(P<0.05)at the same time,the skull surface erosion rate of the titanium particle implantation group was higher than that of the Staphylococcus aureus group(P<0.05);3)the effect of titanium particles and Staphylococcus aureus on osteoclasts: Trap positive cells in the titanium particle implantation group were more than those in the placebo group and Staphylococcus aureus group(P<0.05)Trap positive cells in the titanium Staphylococcus aureus implantation group had more inflammatory reactions(P<0.05)2.2 Titanium particles and Staphylococcus aureus): 1)TNF-alpha was highly expressed in both titanium particles implantation group and Staphylococcus aureus group(P<0.05).The expression of TNF-alpha in titanium particle implantation group was higher than that in Staphylococcus aureus implantation group(P<0.05);2)IL-1beta was highly expressed in both titanium particle implantation group and Staphylococcus aureus group(P<0.05).The expression of IL-1 beta in titanium particle implantation group was higher than that in Staphylococcus aureus implantation group(P<0.05);3)The expression of IL-6 was higher in both titanium particle implantation group and Staphylococcus aureus group(P<0.05).Meanwhile,the expression of IL-6 in Staphylococcus aureus implantation group was higher than that in titanium particle implantation group(P<0.05);4)Th17 cells in titanium particle implantation group and Staphylococcus aureus group were more distributed than that in placebo group(P<0.05).Compared with the titanium particle implantation group and the Staphylococcus aureus implantation group,Th17 cells were more distributed in the Staphylococcus aureus group(P<0.05)2.3ASL and PJI groups)and the expression of inflammatory factors in the periprosthetic tissues: 1)There was a large amount of IL-1beta expression in the periprosthetic tissues of the ASL group and the PJI group,and there was no difference in the expression level between the two groups(P>0.05);2)The tissue infected around the prosthesis in the PJI group.The expression of IL-6 and TNF-alpha in periprosthetic tissues of aseptic loosening was higher than that in periprosthetic tissues of aseptic loosening(P<0.05)2.4ASL and PJI groups): 1)The expression of osteoclast-related factors in periprosthetic tissues of aseptic loosening was higher than that in periprosthetic tissues of infective loosening(P<0.05)2)NFATC1 and NF-kappa B were expressed in both groups,but there was no significant difference(P>0.05).3.Sigle-stage treatment of chronic infected total hip arthroplasty with uncemented reconstruction,89.2% patients were free of infection,the mean postoperative Harris hip score was 80 points(63 to 92 P<0.05).Conclusion: 1)The sensitivity and specificity of D-dimer in serological diagnosis of periprosthetic infection are low,so it cannot be used alone to diagnose PJI,while IL-6has high sensitivity and specificity.When combined with CRP and ESR,its diagnostic efficiency increases.As a new diagnostic index,PD-L1 has good sensitivity and specificity.2)Sonication of arthroplasty implants is still a simple and convenient method to find pathogenic bacteria of PJI.3)Shotgun Metagenomic Sequencing is an effective tool for the diagnosis of pathogenic bacteria around articular prosthesis,especially for culturally negative infections.4)The mechanism of bone destruction caused by periprosthetic infection and aseptic loosening is interrelated,but there are also some differences.5)Siglestage treatment of chronic infected total hip arthroplasty with uncemented reconstruction is one of the effective methods to treat periprosthetic infection.