Sonication versus vortexing of implants for diagnosis of prosthetic joint infection

Abstract

Biofilm removal efficacy of vortexing alone was compared with the standard vortexing-sonication procedure. Among 135 removed prostheses, 35 were diagnosed with infection and 100 with aseptic failure. At a cutoff of ≥ 50 CFU/ml, sonication was more sensitive than vortexing (60% versus 40%, P = 0.151), while the specificity was 99% for both methods.

Fig 1

Effect of previous antimicrobial therapy on sensitivity of sonication and vortexing fluid cultures, using cutoffs of ≥50 CFU/ml (A) and ≥1 CFU/ml (B), or stratified according to patients with acute PJI (C) and chronic PJI (D) using a cutoff of ≥50 CFU/ml.

Fig 2

Microorganisms detected by vortexing fluid cultures (n = 27) and sonication fluid cultures (n = 29). The dashed line indicates a cutoff value of ≥50 CFU/ml of the same microorganism. Solid circles denote microorganisms isolated from patients who had received previous antimicrobial treatment; open circles denote microorganisms isolated from patients who had not received previous antimicrobial treatment. Triangles denote microorganisms isolated from thioglycolate broth only. CNS denotes coagulase-negative staphylococci. Numbers in parentheses represent numbers of patients.