Objective To investigate the efficiency of 16S rRNA Real-time reverse transcription PCR technique in the diagnosis of periprosthetic joint infection,and compare its sensitivity and specificity with conventional culture.Methods There were 43 revision cases from July 2013 to December 2015.Synovial fluid collected by puncture preoperatively,tissues from five different parts around the prosthesis collected intra-operatively were cultured by blood plate and BacT/Alert FN respectively.The 16S rRNA in interface membrane was detected by real-time reverse transcription PCR as a marker to diagnose PJI.At the same time,the synovial fluid was routinely bacterial cultured.We compared the sensitivity and specificity of two methods.Results There are 22 THAs and 21 TKAs respectively in 43 cases,23 cases diagnosed prosthetic joint infection and 20 cases diagnosed non prosthetic joint infection.The sensitivity of 16S rRNA Real-time reverse transcription PCR is higher than the conventional bacterial culture (78.2％ vs.47.8％).There was no difference in the specificity and PPV and NPV.For PCR in prosthetic joint infection group,Staphylococcus epidermidis in 5 cases,Staphylococcus aureus in 3 cases,streptococcus in 4 cases,E.coli in 2 cases,Staphylococcus lugdunensis,Pseudomonas aeruginosa,Staphylococcus haemolyticus and Mycoplasma in 1 case respectively.For culture in prosthetic joint infection group,Staphylococcus epidermidis in 5 cases,Staphylococcus aureus in 2 cases,Staphylococcus lugdunensis,Pseudomonas aeruginosa,Staphylococcus haemolyticus and E.coli in 1 case respectively.For non prosthetic joint infection group,PCR and culture are all negative.Conclusion The sensitivity of 16S rRNA Real-time reverse transcription PCR is higher than the conventional bacterial culture.

Objective:To investigate whether the prophylactic use of a dose of sensitive antibiotics before revision for periprosthetic joint infection (PJI) may affect the positive rate of intraoperative specimen culture.Methods:This prospective study recruited the patients who underwent revision due to PJI from July 1, 2017 to February 1, 2019 at Department of Orthopaedics, The First Affiliated Hospital to Fujian Medical University. After use of antibiotics was stopped in all patients for 2 weeks before operation, synovial fluid was extracted for culture to confirm pathogenic bacteria and drug sensitivity and some/all of the prostheses were removed during operation. According to their sequence number of admission, the patients were randomly divided into group A and group B. Samples were taken in group A after a dose of sensitive antibiotics was administered 30 to 60 minutes before revision while a dose of sensitive antibiotics was given in group B after all samples were taken. Intra-operatively, synovial fluid, tissue grinding fluid (TGF) and ultrasonic prosthesis lysate (UPL) were taken for aerobic and anaerobic culture. According to whether there was a positive culture of at least one microbiological specimen, the preoperative and intraoperative culture results were analyzed and compared between the 2 groups.Results:A total of 32 PJI patients were included in this study due to positive culture of synovial fluid before operation, with 16 cases in group A and 16 in group B. The most common infection bacteria were staphylococci (59.3%, 19/32). There was no significant difference in age, gender, mode of operation, Tsukayama classification, prosthesis removal, preoperative ESR, CRP, synovial fluid white blood cell count (SF-WBC) or polymorphonuclear cell percentage (PMN) between the 2 groups. The positive rates of synovial fluid, tissue, TGF and UPL were 81.3% (13/16), 62.5% (10/16), 93.8% (15/16) and 93.8% (15/16) for group A, and 87.5% (14/16), 68.8% (11/16), 93.8% (15/16) and 100.0% (16/16) for group B, showing insignificant differences between the 2 groups ( P>0.05). The positive rates of TGF and UPL culture showed no significant difference between them in group A or in group B ( P>0.05), but they were significantly higher than those of traditional tissue culture ( P<0.05). Conclusions:As prophylactic use of antibiotics before PJI revision may not affect the positive rate of intraoperative specimen culture, it is not necessary to postpone use of prophylactic antibiotics before PJI revision. Furthermore, as positive rates of TGF and UPL culture are similar but significantly higher than those of traditional tissue culture, tissue grinding can be used to improve the positive rate of tissue culture.

Objective To investigate the role of next generation sequencing technology in the detection of pathogenic bacteria in synovial fluid of prosthetic joint infection.Methods Nine samples of synovial fluid specimens of prosthetic joint infection patients with positive microbial culture from October,1 2016 to April 1,2017 were collected.Each specimen (200 μl) was used for next generation sequencing.Total DNA was extracted from synovial fluid samples.The collected DNA samples were amplified by PCR in the V4 region of 16S rDNA gene.The amplified products were sequenced using the Illumina Miseq platform,2× 250 bp double-end sequencing strategy.The sequencing results were compared with the SILVA database to analyze the types of bacteria and relative abundance in the DNA samples.A total of 200 μl sterile double-distilled deionized water was used as control.Results Nine cases of microbial culture positive prosthetic joint infection synovial fluid DNA samples were sequenced by 16S rDNA amplicon sequencing and yielded 3 132 415 high-quality reads and 3 752 operational taxonomic units (OTU).At the level of bacteria,a total of 9 different bacterial gates were detected on 9 DNA samples.At the level of bacteria,34 different bacteria were detected by 16S rDNA amplicon sequencing.Each DNA sample was detected by 16S rDNA amplicon sequencing and the bacterial genus was identical to that of laboratory culture.16S rDNA amplicon sequencing detected more species of bacteria [6(3,9.5)] than bacterial cultures [(1.0(1.0,1.0)].There was statistically significant difference in the number of bacteria detected in the same specimen between the 16S rDNA amplicon sequencing and the laboratory culture (Z=2.533,P=0.011).Among them,the dominant bacterial population (highest abundance) detected by 16S rDNA amplicon sequencing in four DNA samples was consistent with the results of laboratory culture.Conclusion In the prosthetic joint infection,the 16S rDNA amplicon sequencing technology can accurately detect pathogens that are consistent with the laboratory culture,and can detect other bacteria outside the laboratory culture.This technology can provide the basis for clinical diagnosis and antibiotic selection.

Objective:To analyze the clinical efficacy of two-stage total hip arthroplasty in the treatment of chronic septic hip arthritis.Methods:From January 2008 to March 2020, 17 patients with chronic septic hip arthritis (17 hips) received two-stage total hip arthroplasty at Department of Orthopaedic Surgery, The First Affiliated Hospital to of Fujian Medical University. They were 11 males and 6 females, with an average age of 54.5 years (from 19 to 77 years) and 9 left and 8 right hips affected. There were 10 cases of primary septic hip and 7 cases of secondary infection after hip surgery. Three patients had undergone debridement in other hospitals and one patient had developed a sinus tract. In the first stage operation, the diseased femoral head and neck were resected to implant an articulating spacer after thorough debridement; in the second stage operation, the spacer was removed to implant a uncemented artificial hip prosthesis in 16 cases or a cemented artificial hip prosthesis in one case. Recorded were the results of microbial culture, operation time, intraoperative blood loss, and therapeutic outcomes of the patients.Results:Pathogenic data were available in 13 patients and the culture was negative in 4. The pathogens were detected by metagenomic next-generation sequencing in 2 patients with culture negative. In the first stage operation, operation time averaged 140.6 min (from 90 to 176 min) and intraoperative blood loss 361.8 mL(from 100 to 1 000 mL); in the second stage operation, operation time averaged 130.3 min (from 91 to 166 min)and blood loss 291.2 mL(from 50 to 700 mL). The average interval between the first and the second stage operations was 115.0 days(from 66 to 227 d). During the interval, spacer fracture occurred in one case, spacer dislocation in one case and lower extremity deep venous thrombosis in one case. All the patients were followed up for 12 to 82 months (average, 36.7 months) after second stage operation. The inflammatory indexes decreased to normal in all the 17 patients and infection recurrence was observed in none of them.Conclusions:Two-stage total hip arthroplasty may result in a high rate of successful treatment of chronic septic hip arthritis. Specific use of sensitive antibiotics after identification of specific pathogenic microorganisms by multiple methods is the key to a successful treatment.