Using Preoperative Staphylococcus aureus Screening and Surgical Site Disinfection to Decrease Surgical Site Infections in Patients Undergoing Elective Total Hip (THA) and Total Knee Arthroplasty (TKA)

Background: Staphlylococcus aureus (SA) has been recovered from approximately 50% of the prosthetic joint replacement-related surgical site infections (SSI) identified at the Hospital of St Raphael.  Nasal (and probably skin) carriage of SA by patients is a recognized risk factor for SA SSI.  In 2008, we undertook a program targeting endogenous SA carriage to decrease surgical site contamination leading to SSI. 

Objective: To decrease the occurence of postoperative SSI in patients undergoing THA and TKA surgery.

Methods: Our program, instituted in June, 2008, recommended that all patients scheduled for THA or TKA surgery undergo an anterior nares culture preoperatively to detect SA colonization.  For patients testing positive, mupiricin ointment was administered for 2 days prior to surgery.  Each patient received a packet of 2 chlorhexidine gluconate (CHG) impregnated cloths. Patients used one cloth to clean the surgical site and the second cloth to clean the surrounding skin the night before surgery. This process was repeated at the hospital on the morning of surgery.  Other components of the SSI prevention bundle included clipping rather than shaving the surgical site when hair must be removed and proper prophylactic antibiotic administration.  Surveillance was conducted utilizing the National Healthcare Safety Network (NHSN) methodology. We calculated SSI rates for a baseline period, 9/1/07 to 5/31/08 and a post intervention time period, 6/1/08 – 6/30/09. 

Results: For THA, the baseline infection rate was 3.0% and decreased to 1.0% during the post intervention time period.  Five of 8 infections pre intervention were caused by SA while only one was identified during the 13 months following the new protocol.  For TKA, the SSI rate was 1.0% in the baseline period, 0.84% in the post intervention period.  Two infections were caused by SA in the baseline period, 4 infections in the post intervention period.

Conclusions: Although not statistically significant, we have realized decreases in the occurence of SSI in our patient population, especially in the patients undergoing THA.  Improved compliance with all aspects of the prevention program is needed to establish if significant reductions can be achieved in SSI related to THA and TKA.