Relationship between the degree of osteolysis and cultures obtained by sonication of the prostheses in patients with aseptic loosening of a hip or knee arthroplasty
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The pathogenesis of prosthesis loosening is not well understood. The aim of our study was to sonicate components of joint prostheses removed due to aseptic loosening, culture the sonicate fluid, and to correlate these results with the degree of radiological osteolysis.
From January 2008 to June 2009 all consecutive patients who underwent a revision of hip or knee prosthesis due to aseptic loosening were included in the study. Aseptic loosening was established when the patient had radiological signs of loosening without symptoms or signs of infection. The diagnosis was confirmed when histology was negative, and ≥5 out of 6 standard cultures of periprosthetic tissue were negative. Bone lysis was measured according to the Paprosky or Engh classifications without knowing the result of sonication cultures. Removed components were placed in sterile bags and immediately transported to the microbiology laboratory and sonicated. Sonicate fluid was cultured and the results were correlated with the degree of bone lysis. The proportion of components with positive sonication culture according to the bone lysis classification was compared using χ2 test.
A total of 52 patients were included and 123 components were sonicated. In 30 patients at least 1 sonicated component was positive (57.7%) and 44 out of 123 (35.8%) components were positive. The proportion of positive sonication cultures was significantly higher in the group of components with a higher degree of bone lysis of 3 (76.5%) than in those with lower degrees (33.9% for 1 and 24% for 2) (χ2 test, p = 0.0004).
Sonication cultures were positive in 57% of patients who underwent revision arthroplasty for aseptic loosening. The percentage of positive sonication cultures was significantly higher in patients with severe osteolysis.
Level of evidence
level I of Prognostic Studies—Investigating the Effect of a Patient Characteristic on the Outcome of Disease.
KeywordsRevision Sonication Hip arthroplasty Infection Knee arthroplasty Revision
- 5.Engesaeter LB, Lie SA, Espehaug B, Furnes O, Vollset SE, Havelin LI (2003) Antibiotic prophylaxis in total hip arthroplasty: effects of antibiotic prophylaxis systemically and in bone cement on the revision rate of 22, 170 primary hip replajcements followed 0–14 years in the Norwegian Arthroplasty Register. Acta Orthop Scand 74:644–651PubMedCrossRefGoogle Scholar
- 8.Tunney MM, Patrick S, Curran MD, Ramage G, Hanna D, Nixon JR, Gorman SP, Davis RI, Anderson N (1999) Detection of prosthetic hip infection at revision arthroplasty by immunofluorescence microscopy and PCR amplification of the bacterial 16S rRNA gene. J Clin Microbiol 37:3281–3290PubMedGoogle Scholar