Abstract
Purpose
Surgical site infection (SSI) is an infrequent but serious complication of total joint arthroplasty (TJA). Orthopaedic SSI causes substantial morbidity, prolonging the hospital stay by a median of 2 weeks, doubling the rates of rehospitalization, and more than tripling overall healthcare costs. Colonization with methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) is known to be associated with an increased risk of subsequent SSI. Carriers are two to nine times more likely to acquire S. aureus SSIs than non-carriers. Screening of the nose and throat for MRSA colonization and preoperative patient decolonization have been shown to decrease the incidence of subsequent MRSA infection. The aim of this study was to investigate the association between the results of MRSA colonization screening and the incidence of SSI in our hospital.
Materials and Methods
Between June 2007 and June 2010, 238 patients were admitted for TJA, among whom 235 underwent preoperative assessment that included screening of the nose and throat for MRSA colonization. Fifty-nine of these patients underwent total hip arthroplasty (THA), 69 underwent total knee arthroplasty (TKA), 6 underwent unilateral knee arthroplasty (UKA), and 101 underwent bipolar hip prosthesis arthroplasty (BPH). The mean age of the patients was 72.7 (49–95) years and the male to female ratio was 1:3.8. We analyzed these patients retrospectively, and determined the site of colonization, eradication prior to surgery, and subsequent development of SSI in the year after surgery. SSI was defined according to the criteria established by the Centers for Disease Control and Prevention.
Results
MRSA colonization was positive in 12 patients (5.1%) at the initial preoperative assessment (Fig. 1). All except 2 of the positive patients underwent nasal eradication with mupirocin 2% three times daily for three days. Eight of 10 patients were confirmed to be MRSA-negative after re-swabbing. During surgery, all patients received perioperative antibiotic prophylaxis. The standard regimen was cefazolin 1 g administered 15 to 30 min before incision, followed by 1 g every 3 hours until skin closure. One hundred eighty-six patients were monitored for development of SSIs for 1 year after TJA. Among these patients, 1 in the MRSA-positive group and 1 in the negative group developed MRSA SSIs (P<0.01)(Fig. 2).
Discussion
Bode et al. recently reported that rapid screening and decolonizing of nasal S. aureus carriers with intranasal mupirocin prevented SSIs after mixed surgery. However, several studies of the effect of screening and decolonization for such carriers have yielded paradoxical findings because of differences in study design or sample size.
Conclusion
We conclude that MRSA-colonized patients undergoing TJA are at an increased risk of SSI, despite eradication therapy prior to surgery. Use of prophylactic antibiotics such as vancomycin or teicoplanin may be beneficial.
