Decreased surgical site infection (SSI) rates for hip and knee arthroplasty following multiple infection control interventions

Abstract

BACKGROUND/OBJECTIVES: In response to a perceived increase in SSIs following hip and knee arthroplasty, retrospective surveillance was performed at a 1442-bed tertiary care university hospital for procedures performed during 2003. This revealed a hip arthroplasty SSI rate of 2.6 SSI/100 procedures (12/465) and a knee arthroplasty SSI rate of 2.5 SSI/100 procedures (8/342). These rates are higher than the 2003 National Nosocomial Infections Surveillance System (NNIS) pooled means of 1.5 SSI/100 hip procedures and 1.2 SSI/100 knee procedures. SSIs are associated with increased morbidity and mortality rates and prolonged hospital stay, and can result in permanent disability. Active surveillance with feedback of rates, education regarding best practice, operating room (OR) observations to identify lapses in infection control (IC) procedures, and recommendations to improve practice were implemented to reduce hip and knee arthroplasty SSI rates. METHODS: Clean, Class I hip or knee arthroplasty SSIs were identified using NNIS definitions. Feedback of rates to surgical teams was accomplished through meetings with stakeholders and letters to surgeons. OR staff education was accomplished through inservices and a self-study SSI prevention module. IC specialists performed OR observations, and recommendations were shared with stakeholders and integrated into OR IC practices. These recommendations included improving preoperative prophylactic antibiotic timing, scheduling infected cases later in the day, decreasing flash sterilization, and ensuring that surgeons mask prior to entering the OR and donning Stryker helmets/hoods. Additional recommendations involved performing appropriate skin prep, decreasing OR room traffic, and wearing appropriate attire. RESULTS: The 2003 hip SSI rate was 2.6 SSI/100 procedures (12/465). The 2004 hip SSI rate was 1.5 SSI/100 procedures (7/433), a rate decrease of 42% (p=0.33). The 2003 knee SSI rate was 2.5 SSI/100 procedures (8/342). The 2004 knee SSI rate was 2.1 SSI/100 procedures (6/305), a rate decrease of 16% (p=0.75). CONCLUSIONS: Active surveillance combined with multiple SSI prevention interventions targeted at education, observation, and feedback to the surgical team measurably lowered SSI rates following hip and knee arthroplasty, although these decreases were not statistically significant. The next step is a case control study to determine risk factors specific to this institution for SSIs following hip and knee arthroplasty.