title: Inflammatory blood laboratory levels as markers of prosthetic joint infection: a systematic review and meta-analysis.
abstract: BACKGROUND
  The preoperative diagnosis of prosthetic joint infection in patients with a total hip or knee arthroplasty may rely in part on the use of systemic inflammation markers. These markers have unclear accuracy. The objective of this review was to summarize the evidence on the accuracy of the peripheral white blood-cell count, the erythrocyte sedimentation rate, serum C-reactive protein levels, and serum interleukin-6 levels for the diagnosis of prosthetic joint infection.
  
  
  METHODS
  We searched electronic databases (MEDLINE, EMBASE, Cochrane Library, Web of Science, and Scopus) from 1950 through 2009. Eligible studies evaluated the accuracy of white blood-cell count, erythrocyte sedimentation rate, serum C-reactive protein level, and serum interleukin-6 level for the intraoperative diagnosis of prosthetic joint infection at the time of revision arthroplasty. Two reviewers working independently extracted study characteristics and data to estimate the diagnostic odds ratio and 95% confidence interval for each result.
  
  
  RESULTS
  We included thirty eligible studies that included 3909 revision total hip or knee arthroplasties. The prevalence of prosthetic joint infection was 32.5% (1270 of 3909). The accuracy of assessed inflammation markers, represented with a diagnostic odds ratio, was 314.7 (95% confidence interval, 113.0 to 876.8) for interleukin-6 (three studies), 13.1 (95% confidence interval, 7.9 to 21.7) for C-reactive protein level (twenty-three studies), 7.2 (95% confidence interval, 4.7 to 10.9) for erythrocyte sedimentation rate (twenty-five studies), and 4.4 (95% confidence interval, 2.9 to 6.6) for white blood-cell count (fifteen studies).
  
  
  CONCLUSIONS
  The diagnostic accuracy for prosthetic joint infection was best for interleukin-6, followed by C-reactive protein level, erythrocyte sedimentation rate, and white blood-cell count. Given the limited numbers of studies assessing interleukin-6 levels, further investigations assessing the accuracy of interleukin-6 for the diagnosis of prosthetic joint infection are warranted.
authors.affiliation: Section of Orthopedic Infectious Diseases, Mayo Clinic College of Medicine, 200 First Street S.W., Rochester, MN 55905, USA. berbari.elie@mayo.edu
authors.forename: Elie
authors.initials: E
authors.lastname: Berbari
authors.forename: Tad
authors.initials: T
authors.lastname: Mabry
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Tsaras
authors.forename: Mark
authors.initials: M
authors.lastname: Spangehl
authors.forename: Pat J
authors.initials: PJ
authors.lastname: Erwin
authors.forename: Mohammad Hassan
authors.initials: MH
authors.lastname: Murad
authors.forename: James
authors.initials: J
authors.lastname: Steckelberg
authors.forename: Douglas
authors.initials: D
authors.lastname: Osmon
mesh_terms: D015415:Biomarkers / Q000097:blood; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000032:analysis; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood; D007595:Joint Prosthesis / Q000009:adverse effects*; D007958:Leukocyte Count; D016017:Odds Ratio; D016459:Prosthesis-Related Infections / Q000097:blood / Q000175:diagnosis*; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D018836:Inflammation Mediators; D015850:Interleukin-6; D002097:C-Reactive Protein