title: Risk factors for total joint arthroplasty infection in patients receiving tumor necrosis factor α-blockers: a case-control study.
abstract: BACKGROUND
  The objective of this study was to assess natural microbial agents, history and risk factors for total joint arthroplasty (TJA) infections in patients receiving tumor necrosis factor (TNF)α-blockers, through the French RATIO registry and a case-control study.
  
  
  METHODS
  Cases were TJA infections during TNFα-blocker treatments. Each case was compared to two controls (with TJA and TNFα-blocker therapy, but without TJA infection) matched on age (±15 years), TJA localization, type of rheumatic disorder and disease duration (±15 years). Statistical analyses included univariate and multivariate analyses with conditional logistic regression.
  
  
  RESULTS
  In the 20 cases (18 rheumatoid arthritis), TJA infection concerned principally the knee (n = 12, 60%) and the hip (n = 5, 25%). Staphylococcus was the more frequent microorganism involved (n = 15, 75%). Four patients (20%) were hospitalized in an intensive care unit and two died from infection. Eight cases (40%) versus 5 controls (13%) had undergone primary TJA or TJA revision for the joint subsequently infected during the last year (P = 0.03). Of these procedures, 5 cases versus 1 control were performed without withdrawing TNFα-blockers (P = 0.08). In multivariate analysis, predictors of infection were primary TJA or TJA revision for the joint subsequently infected within the last year (odds ratio, OR = 88.3; 95%CI 1.1-7,071.6; P = 0.04) and increased daily steroid intake (OR = 5.0 per 5 mg/d increase; 1.1-21.6; P = 0.03). Case-control comparisons showed similar distribution between TNFα-blockers (P = 0.70).
  
  
  CONCLUSIONS
  In patients receiving TNFα-blockers, TJA infection is rare but potentially severe. Important risk factors are primary TJA or TJA revision within the last year, particularly when TNFα-blockers are not interrupted before surgery, and the daily steroid intake.
authors.affiliation: Rheumatology B Department, Cochin Hospital, Paris 75014, France. melanie.gilson@gmail.com
authors.forename: Mélanie
authors.initials: M
authors.lastname: Gilson
authors.forename: Laure
authors.initials: L
authors.lastname: Gossec
authors.forename: Xavier
authors.initials: X
authors.lastname: Mariette
authors.forename: Dalenda
authors.initials: D
authors.lastname: Gherissi
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Guyot
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Berthelot
authors.forename: Daniel
authors.initials: D
authors.lastname: Wendling
authors.forename: Christian
authors.initials: C
authors.lastname: Michelet
authors.forename: Pierre
authors.initials: P
authors.lastname: Dellamonica
authors.forename: Florence
authors.initials: F
authors.lastname: Tubach
authors.forename: Maxime
authors.initials: M
authors.lastname: Dougados
authors.forename: Dominique
authors.initials: D
authors.lastname: Salmon
mesh_terms: D000368:Aged; D019643:Arthroplasty, Replacement / Q000706:statistics & numerical data*; D016022:Case-Control Studies; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D016867:Immunocompromised Host; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012042:Registries / Q000706:statistics & numerical data; D012216:Rheumatic Diseases / Q000188:drug therapy / Q000401:mortality / Q000601:surgery; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000401:mortality*; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
chemical_list: D007166:Immunosuppressive Agents; D014409:Tumor Necrosis Factor-alpha