Sonication versus Tissue Sampling for Diagnosis of Prosthetic Joint and Other Orthopedic Device-Related Infections

Abstract

Current guidelines recommend collection of multiple tissue samples for diagnosis of prosthetic joint infections (PJI). Sonication of explanted devices has been proposed as a potentially simpler alternative; however, reported microbiological yield varies. We evaluated sonication for diagnosis of PJI and other orthopedic device-related infections (DRI) at the Oxford Bone Infection Unit between October 2012 and August 2016. We compared the performance of paired tissue and sonication cultures against a "gold standard" of published clinical and composite clinical and microbiological definitions of infection. We analyzed explanted devices and a median of five tissue specimens from 505 procedures. Among clinically infected cases the sensitivity of tissue and sonication culture was 69% (95% confidence interval, 63 to 75) and 57% (50 to 63), respectively ( < 0.0001). Tissue culture was more sensitive than sonication for both PJI and other DRI, irrespective of the infection definition used. Tissue culture yield was higher for all subgroups except less virulent infections, among which tissue and sonication culture yield were similar. The combined sensitivity of tissue and sonication culture was 76% (70 to 81) and increased with the number of tissue specimens obtained. Tissue culture specificity was 97% (94 to 99), compared with 94% (90 to 97) for sonication ( = 0.052) and 93% (89 to 96) for the two methods combined. Tissue culture is more sensitive and may be more specific than sonication for diagnosis of orthopedic DRI in our setting. Variable methodology and case mix may explain reported differences between centers in the relative yield of tissue and sonication culture. Culture yield was highest for both methods combined.

Current Clinical Methods for Detection of Peri-Prosthetic Joint Infection

“…Yan et al [28] examined sonication fluid cultures and found similar results, with sensitivity of 73.1% and specificity of 96.0%. These results, however, are not consistent with another study by Dudareva et al [29] showing a reduction in sensitivity from 97% to 76% and specificity from 69% to 57% with sonication compared wit tissue culture.…”

Polymicrobial infections and microbial patterns in infected nonunions – a descriptive analysis of 42 cases

“…The fact, that instead of five relevant tissue samples, at least three relevant tissue samples were sent to microbiological diagnostics is a further downside. The recent understanding, that five relevant tissue samples increase microbial sensitivity in PJI and FRI, was not known for the observation period and thus retrospective analysis not possible [26] . The same applies to the laboratory culture work-up.…”

The accuracy of diagnostic Imaging techniques in patients with a suspected Fracture-related Infection (IFI) trial: study protocol for a prospective multicenter cohort study.

“…These cultures will be sampled in a protocolled manner with clean surgical instruments for each sample to avoid cross contamination 26. Preferably all antibiotics are discontinued for at least 2 weeks and antibiotic prophylaxis is withheld until the last sample is obtained 27 28. The criteria for a positive result based on operatively obtained cultures are listed in box 1 (a).…”