title: Prosthetic joint infections due to Staphylococcus aureus and coagulase-negative staphylococci.
abstract: OBJECTIVE
  To evaluate the specific characteristics, outcome, and predictors of failure of prosthetic joint infections (PJI) due to S. aureus and coagulase-negative staphylococci (CNS) treated with open debridement and retention of the implant.
  
  
  METHODS
  PJI due to S. aureus or CNS prospectively registered in a database from 1999 to 2009 were retrospectively reviewed. During the study period, 106 patients met the inclusion criteria. The mean follow-up period was 3.8 years and for at least 2 years in all patients. The failure rate was 23.6% (25 out of 106). The only variable significantly associated with failure in the global cohort was polymicrobial infection (38.7% vs. 17.3%, p = 0.024). Fifty-seven (53.8%) patients had an infection due to S. aureus and 49 (46.2%) due to CNS. Among S. aureus infections, 95% corresponded to primary arthroplasties while 98% of PJIs due to CNS were after revision arthroplasties (p<0.001). C-reactive protein was significantly higher in PJI due to S. aureus (9.5 mg/dl vs. 4.9 mg/dl, p = 0.007). The rate of methicillin-resistance (8.8% vs. 59.2%, p<0.001) and fluoroquinolone-resistance (15.8% vs. 34.7%, p = 0.005) was significantly higher in CNS infections. The global failure rate was higher in S. aureus infections (28% vs. 18.3. p = 0.26). In S. aureus infections, patients diagnosed within the first 15 days after joint arthroplasty (p = 0.031) and with bacteremia (p = 0.046) had poor pro-gnosis. In CNS infections only the location of the prosthesis (knee 27.6% vs. hip 5%, p = 0.045) was associated with failure.
  
  
  CONCLUSIONS
  PJIs due to S. aureus were mainly in primary arthroplasties; they had a higher inflammatory response; and the strains were more susceptible to fluoroquinolones and methicillin than CNS infections. S. aureus infections had a higher failure rate than CNS infections, however, the difference was not statistically significant. There were few factors associated with failure and they were different in S. aureus and CNS infections.
authors.affiliation: Department of Orthopedic Surgery and Traumatology, Hospital Clinic of Barcelona, Barcelona, Spain. etornero@clinic.ub.es
authors.forename: Eduard
authors.initials: E
authors.lastname: Tornero
authors.forename: Ester
authors.initials: E
authors.lastname: García-Oltra
authors.forename: Sebastían
authors.initials: S
authors.lastname: García-Ramiro
authors.forename: Juan C
authors.initials: JC
authors.lastname: Martínez-Pastor
authors.forename: Jordi
authors.initials: J
authors.lastname: Bosch
authors.forename: Consuelo
authors.initials: C
authors.lastname: Climent
authors.forename: Laura
authors.initials: L
authors.lastname: Morata
authors.forename: Pilar
authors.initials: P
authors.lastname: Camacho
authors.forename: Josep
authors.initials: J
authors.lastname: Mensa
authors.forename: Alex
authors.initials: A
authors.lastname: Soriano
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D019643:Arthroplasty, Replacement / Q000009:adverse effects* / Q000295:instrumentation; D016009:Chi-Square Distribution; D003646:Debridement; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D007595:Joint Prosthesis / Q000009:adverse effects* / Q000382:microbiology; D053208:Kaplan-Meier Estimate; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D016459:Prosthesis-Related Infections / Q000188:drug therapy / Q000382:microbiology* / Q000601:surgery; D012042:Registries; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology* / Q000601:surgery; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification*; D013997:Time Factors; D017211:Treatment Failure
chemical_list: D000900:Anti-Bacterial Agents