Sonication of retrieved implants improves sensitivity in the diagnosis of periprosthetic joint infection

Abstract

BackgroundSonication is a valuable tool in the diagnosis of periprosthetic joint infections (PJI). However, conditions and definition criteria for PJI vary among studies. The aim of this study was to determine the diagnostic performance (i.e., specificity, sensitivity) of sonicate fluid culture (SFC) against periprosthetic tissue culture (PTC), when using European Bone and Joint Infection Society (EBJIS) criteria.MethodsFrom March 2017 to April 2018, 257 implants were submitted for sonication. PJI was defined according to the EBJIS criteria as well as according to the International Consensus Meeting criteria of 2018 (ICM 2018). Only cases with at least one corresponding tissue sample were included. Samples were cultured using traditional microbiological plating techniques. Sensitivity and specificity were determined using two-by-two contingency tables. McNemar’s test was used to compare proportions among paired samples. Subgroup analysis was performed dividing the cohort according to the site of PJI, previous antibiotic treatment, and time of manifestation. Prevalence of pathogens was determined for all patients as well as for specific subgroups.ResultsAmong the 257 cases, 145 and 112 were defined as PJI and aseptic failure, respectively. When using the EBJIS criteria, the sensitivity of SFC and PTC was 69.0 and 62.8%, respectively (p = .04). Meanwhile, the specificity was 90.2 and 92.9%, respectively (p = .65). When adopting ICM 2018 criteria, the sensitivity of SFC and PTC was 87.5 and 84.4% (p = .63) respectively, while the specificity was 85.1 and 92.5% (p = .05), respectively. The most commonly identified pathogens were coagulase-negative staphylococci (26% overall), while 31% of PJI were culture-negative and 9% polymicrobial.ConclusionsSFC exhibited significantly greater sensitivity versus PTC when using the EBJIS criteria. Nevertheless, the diagnosis of PJI remains a difficult challenge and different diagnostic tools are necessary to optimize the outcome.

Effects of different pretreatment methods on microbial yield from infected tissues

“…This study found that the average CFUs obtained from tissues pretreated by MH in every model were higher than that pretreated by DC and MM, which is basically consistent with the results of Sylvio Redanz et al [11]. The DTT and SF were also performed in this study because previous reported that the DTT can homogenize tissues and facilitate microorganisms release from tissue samples [7], and the application of SF was reported to break the biofilm on the surface of a prosthesis and thus promote bacteria release [13][14][15][16]. And we showed that DTT's ability to facilitate bacteria release from infectious tissues was similar to that of MH, while SF's ability to promote bacteria release from tissues was not as good as that of MH and DTT.…”

The impact of sonication cultures when the diagnosis of prosthetic joint infection is inconclusive

“…Moreover, the diagnosis of PJI was improved by using sonication fluid cultures for all the criteria used in clinical practice. Despite these findings, periprosthetic tissue cultures remain highly specific and the gold standard for microbiological diagnosis [24,25,29].…”

Effects of different pretreatment methods on microbial recovery of infected tissues

“…The pretreatment methods of DTT and SF were added in this study because the literature reports that the mucolytic agent DTT can homogenize tissues and release the microorganisms in tissue samples 7 . The application of SF to break the bio lm on the surface of a prosthesis and to thus release bacteria has been recognized by many researchers [13][14][15][16] . The results of this study show that DTT's ability to separate bacteria on the surface is similar to that of MH, while SF's ability to elute bacteria from tissue surfaces is not as good as that of MH and DTT.…”