Abstract
Prosthetic joint infections (PJI) are amongst the most feared postoperative complication of total joint replacement (TJR). PJIs are associated with significant morbidity ranging from functional impairment to amputation. Staphylococcus aureus (S. aureus) is one of the most common causative organisms involved in PJI. More than one quarter of the general population are S. aureus carriers, and carrier status has been shown to increase the risk of developing surgical site infections including PJIs. Decolonization of S. aureus carriers prior to surgery has demonstrated promising results in general surgery, however, solid evidence supporting decolonization in orthopaedic patients is lacking. We aimed to seek further evidence supporting pre-operative screening and S. aureus decolonization in patients undergoing primary or revision hip and knee TJR.
A quasi-experimental quality improvement study was conducted to compare the 5-year baseline rates of deep PJIs to a one-year screening and decolonization intervention period. All consecutive patients who underwent primary or revision TJR at one tertiary care hospital in Hamilton, ON, Canada were included in both study periods.
Nasal and throat screening for S. aureus carriage of all eligible TJR patients in the preoperative clinic was implemented as standard of care. Patients who tested positive were contacted and provided with details on the S. aureus decolonization protocol. Decolonization included a standardized treatment protocol of 2% intranasal mupirocin twice daily for five days prior to surgery date (excluding day of surgery), and chlorhexidine gluconate wipes (2%) to be used once daily for 4 days prior to surgery date and on the morning of surgery. Regardless of the colonization status at the visit in the preoperative clinic, all patients were re-swabbed on the day of surgery.
Primary outcome of interest was the rate of deep PJI as per CDC/NHSN at one-year postoperative follow-up. Secondary outcomes included rate of deep PJIs due to S. aureus, adherence to the decolonization protocol, proportion of S. aureus carriers successfully decolonized, and the proportion of patients deemed as non-carriers following preoperative swab subsequently identified as carriers on the day of surgery. A total of 8,505 patients were included in the 5-year control group, and 1,883 during the intervention period, of which 424 (22.5%) were identified as S. aureus carriers.
The deep PJI rate was similar in the two groups, 0.4% (7/1,883) in the intervention group and 0.5% (42/8,505) in the control group (OR 0.75, 95%CI 0.34–1.67, p=0.58). More importantly, we found a significant reduction in PJI due to S. aureus to only one case in the intervention period (0.05%) as compared to 29 cases (0.3%) in the historic control (OR 0.15, 95%CI 0.004–0.94, p=0.0376).
We found a significant reduction in PJIs due to S. aureus by decolonizing S. aureus carriers prior to surgery. However, no significant difference in overall infection rates was observed. In conclusion, routine implementation of active screening for S. aureus and decolonization of carriers before TJR is feasible and helps to reduce PJI due to S. aureus.
