title: Clinical and epidemiological differences between implant-associated and implant-free orthopaedic infections.
abstract: OBJECTIVE
  Although there have been many publications regarding the risk factors for implant-associated orthopaedic infections, none have investigated how clinical presentations and epidemiology may differ between infections with and without osteosynthetic material.
  
  
  METHODS
  We pooled clinical data from several databases of adult patients with orthopaedic infections hospitalized at Geneva University Hospitals from January 2004 to December 2014.
  
  
  RESULTS
  Among 2740 episodes of orthopaedic infections, 76% were implant-free osteoarticular or soft tissue infections. Among the 665 (24% of the total episodes) infections that involved osteosynthetic material, 319 (49%) were total joint arthroplasties, 143 single plates, and 50 single nails. The remainders were mixed implant infections, pins, wires, screws, cerclages or spondylodeses. The implant-associated, compared to the implant-free, infections were significantly more frequently associated with female sex, older age, bacteraemia and skin commensal infections, e.g. coagulase-negative staphylococci, corynebacteria or propionibacteria. In contrast, implant-associated infections were significantly less frequently associated with immune suppression, abscess formation, infections due to Staphylococcus aureus or streptococci, polymicrobial pathogens and foot infections. The serum CRP levels at admission were similar (median 82 vs. 75 mg/L).
  
  
  CONCLUSIONS
  Compared to implant-free infections, implant-associated orthopaedic infections are more likely monomicrobial, bacteraemic and due to skin commensals. They involve more often female and older patients, but are less often associated with immune suppression, abscess formation and foot infections.
authors.affiliation: Orthopaedic Surgery Service, Geneva University Hospitals and Faculty of Medicine, University of Geneva, 4, Rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland. celine.cuerel@hcuge.ch.
authors.forename: Céline
authors.initials: C
authors.lastname: Cuérel
authors.affiliation: Orthopaedic Surgery Service, Geneva University Hospitals and Faculty of Medicine, University of Geneva, 4, Rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland.
authors.forename: Sophie
authors.initials: S
authors.lastname: Abrassart
authors.affiliation: Orthopaedic Surgery Service, Geneva University Hospitals and Faculty of Medicine, University of Geneva, 4, Rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland.
authors.forename: Julien
authors.initials: J
authors.lastname: Billières
authors.affiliation: Service of Infectious Diseases, Geneva University Hospitals and Faculty of Medicine, University of Geneva, 4, rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland.
authors.forename: Diego
authors.initials: D
authors.lastname: Andrey
authors.affiliation: Orthopaedic Surgery Service, Geneva University Hospitals and Faculty of Medicine, University of Geneva, 4, Rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland.
authors.forename: Domizio
authors.initials: D
authors.lastname: Suva
authors.affiliation: Orthopaedic Surgery Service, Geneva University Hospitals and Faculty of Medicine, University of Geneva, 4, Rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland.
authors.forename: Victor
authors.initials: V
authors.lastname: Dubois-Ferrière
authors.affiliation: Orthopaedic Surgery Service, Geneva University Hospitals and Faculty of Medicine, University of Geneva, 4, Rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland.|Service of Infectious Diseases, Geneva University Hospitals and Faculty of Medicine, University of Geneva, 4, rue Gabrielle-Perret-Gentil, 1205, Geneva, Switzerland.
authors.forename: Ilker
authors.initials: I
authors.lastname: Uçkay
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001858:Bone Nails / Q000009:adverse effects; D001860:Bone Plates / Q000009:adverse effects; D005260:Female; D006801:Humans; D008875:Middle Aged; D019736:Prostheses and Implants / Q000009:adverse effects*; D016459:Prosthesis-Related Infections / Q000453:epidemiology*; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000453:epidemiology*; D013290:Streptococcal Infections / Q000453:epidemiology*; D013557:Switzerland / Q000453:epidemiology; D055815:Young Adult
keywords: Antibiotic use; Epidemiology; Material; Orthopaedic infections; Skin commensals