title: Infection rates following hip and knee joint arthroplasty: large referral centre versus a small elective-only hospital.
abstract: OBJECTIVE
  The aim of this study was to investigate deep infection rates following hip and knee arthroplasty at a large referral hospital and to compare these rates with a smaller hospital where only elective surgery was performed. Both hospitals were administered by the same public institution.
  
  
  METHODS
  A search of the medical records was performed for all deep infections following elective primary hip and knee arthroplasty; revision procedures were excluded as were total hip replacement and hemiarthroplasty following trauma. To be considered, a deep infection cases must have had bacterial growth confirmed on deep tissue surgical specimens or on aspiration of the joint within 1 year of the index procedure.
  
  
  RESULTS
  There were 14 infections confirmed following 1,160 arthroplasties at the larger hospital and 1 infection for the elective-only hospital following 466 arthroplasties. Statistical analysis showed there was a 7.06 greater chance of having an infection at the larger campus compared with the smaller campus CI (1.3, 130.7). Although there was a trend towards a greater number of infections at the larger hospital, the result was not statistically significant (P = 0.06). We acknowledge there were some differences between the two study populations.
  
  
  CONCLUSIONS
  We found a trend towards, but not a statistically significant difference, between infection rates at the elective-only hospital compared to the larger institution. Given the low overall rate of infection, studies with improved statistical power are needed to determine whether there is a difference in infection rates at smaller elective-only hospitals versus larger hospitals providing elective and non-elective services. The reasons for the difference are likely to be multifactorial. We hypothesise that infection rates are increased in the larger hospital where there is more procedures, both clean and contaminated being performed in the operating theatres, as well as a greater number of inpatient beds and where the hospital admits non-elective cases via its emergency department.
  
  
  METHODS
  Level-two cohort study.
authors: Royal Melbourne Hospital, Melbourne, VIC, Australia. raf.asaid@yahoo.com.au
authors: R
authors: R
authors: Asaid
authors: I
authors: I
authors: Williams
authors: D
authors: D
authors: Hyde
authors: T
authors: T
authors: Tiang
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D005260:Female; D006782:Hospitals, Special / Q000592:standards / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D063728:Secondary Care Centers / Q000592:standards / Q000706:statistics & numerical data*; D013530:Surgical Wound Infection / Q000453:epidemiology*