Clinical Values Of Three Different Diagnostic Methods For Periprosthetic Joint Infection

Objective:Periprosthetic joint infection（PJI）is a serious complication following total joint arthroplasty,it can cause heavy physical and mental burdens for the patients.Apart from the time-consuming management and enormous expense,one challenging problem is the lack of a credible diagnostic method.The objective of this present research is evaluating the clinical value of three different diagnostic methods,including triple-phase bone scanning,sonication and 16S r RNA real-time polymerase chain reaction（RT-PCR）,for periprosthetic joint infection.Methods:Patients undergoing revision surgeries due to persistent pain in the affected limbs after primary arthroplasty（including total hip arthroplasty and total knee arthroplasty）were enrolled to proceed the clinical utility assessment.All patients obtained blood tests,imaging tests and nuclear tests preoperatively.Besides,intraoperative frozen sections and sonication of periprosthetic tissues were performed.The sonication fluid was shipped to the laboratory for culture and 16S r RNA RT-PCR test.The diagnostic standard was formulated based on the Musculoskeletal Infection Society（MSIS）definition of PJI and clinical experience.Sensitivity and specificity of each method were calculated for the evaluation,with using chi-square test.Results:From October 2015 to December 2017,totally 71 patients undergoing revision arthroplasties（62 THA revisions,9 TKA revisions）met the inclusion criteria were involved in this research.According to the diagnostic standard,16 cases were confirmed of PJI,the number of positive cases in triple-phase bone scanning,sonication fluid culture and PCR test were 13（including 3 false-positive cases,SEN 62.5%,SPE 94.5%）,15（including 4 false-positive cases,SEN 68.8%,SPE 92.7%）,21（including8 false-positive cases,SEN 81.3%,SPE 85.5%）,respectively.No significant difference of sensitivity and specificity among these methods was detected（p>0.05）.Conclusions:All the diagnostic methods studied in this research showed higher accuracy than traditional ones.Positive results of ^99mTc-MDP triple-phase bone scanning are significant evidence of PJI.For those who have negative culture,sonication fluid culture can be helpful to detect pathogens.PCR can be applied to identify pathogens in early stage,nevertheless,it`s difficult to be widely used because of the high cost and complexity.