Preoperative Colonization With Staphylococcus Aureus in THA Is Associated With Increased Length of Stay

Abstract

BackgroundStaphylococcus aureus is a common organism implicated in prosthetic joint infection after THA and TKA, prompting preoperative culturing and decolonization to reduce infection rates. It is unknown whether colonization is associated with other noninfectious outcomes of THA or TKA.Questions/purposes(1) What is the association between preoperative S. aureus colonization (methicillin-sensitive S. aureus [MSSA] and methicillin-resistant S. aureus [MRSA]) and the noninfectious outcomes (discharge destination, length of stay, Hip/Knee Disability and Osteoarthritis Outcome Score [HOOS/KOOS] pain score, HOOS/KOOS physical function score, 90-day readmission, and 1-year reoperation) of THA and TKA? (2) What factors are associated with colonization with S. aureus?MethodsBetween July 2015 and March 2019, 8078 patients underwent primary THA in a single healthcare system, and 17% (1382) were excluded because they were not tested preoperatively for S. aureus nasal colonization, leaving 6696 patients in the THA cohort. Between June 2015 and March 2019, 9434 patients underwent primary TKA, and 12% (1123) were excluded because they were not tested for S. aureus colonization preoperatively, leaving 8311 patients in the TKA cohort. The goal of the institution’s standardized care pathways is to test all THA and TKA patients preoperatively for S. aureus nasal colonization; the reason the excluded patients were not tested could not be determined. Per institutional protocols, all patients were given chlorhexidine gluconate skin wipes to use on the day before and the day of surgery, and patients with positive S. aureus cultures were instructed to use mupirocin nasal ointment twice daily for 3 to 5 days preoperatively. Adherence to these interventions was not tracked, and patients were not rescreened to test for S. aureus control. The minimum follow-up time for each outcome and the percentage of the cohort lost for each was: for discharge destination, until discharge (0 patients lost); for length of stay, until discharge (0.06% [4 of 6696] lost in the THA group and 0.01% [1 of 8311] lost in the TKA group); for HOOS/KOOS pain score, 1 year (26% [1734 of 6696] lost in the THA group and 24% [2000 of 8311] lost in the TKA group); for HOOS/KOOS physical function, 1 year (33% [2193 of 6696] lost in the THA group and 28% [2334 of 8311] lost in the TKA group); for 90-day readmission, 90 days (0.06% [4 of 6696] lost in the THA group and 0.01% [1 of 8311] lost in the TKA group); and for 1-year reoperation, 1 year (30% [1984 of 6696] lost in the THA group and 30% [2475 of 8311] lost in the TKA group). Logistic regression models were constructed to test for associations between MSSA or MRSA and nonhome discharge, length of stay greater than 1 day, improvement in the HOOS/KOOS pain subscale (≥ the minimum clinically important difference), HOOS/KOOS physical function short form (≥ minimum clinically important difference), 90-day readmission, and 1-year reoperation. We adjusted for patient-related and hospital-related factors, such as pat...

CORR Insights®: Preoperative Colonization With Staphylococcus Aureus in THA is Associated With Increased Length of Stay

“…The current study [14] is, to my knowledge, the first study to show a relationship between S. aureus colonization and increased LOS after THA and 90-day readmission after TKA, and so we need to determine whether these findings can be consistently replicated in other centers with other patient populations. As the authors point out, it is unlikely that there is a causal link between colonization and the short-term outcomes of arthroplasty, but colonization with S. aureus may serve as a proxy for patient factors that were not explored in the current study.…”

Letter to the Editor: Preoperative Colonization With Staphylococcus Aureus in THA Is Associated With Increased Length of Stay

“…We read your recent article “Preoperative Colonization With Staphylococcus Aureus in THA Is Associated With Increased Length of Stay” with great interest [10]. The study design and data collection were impressive, and the results were well presented.…”

Reply to the Letter to the Editor: Preoperative Colonization With Staphylococcus Aureus in THA Is Associated With Increased Length of Stay

“…We thank CORR ® for allowing us the opportunity to respond to the letter by Drs. Harris and Hegde [4] on our recent article, “Preoperative Colonization With Staphylococcus Aureus in THA Is Associated With Increased Length of Stay” [7].…”

“…First, we agree that S. aureus colonization is a well-established risk factor for surgical site infection after total hip and knee arthroplasty, and that decolonization has been previously demonstrated to be associated with decreased rates of surgical site infection. In this study, after controlling for all variables available at the time, we found that preoperative S. aureus colonization (whether with methicillin-sensitive or methicillin-resistant S. aureus ) was associated with increased length of stay (LOS) after THA and increased odds of readmission after TKA [7]. With this information available, we believe that there is always value in further discussing with patients their risk/benefit profiles, and in this setting, S. aureus colonization was associated with increased LOS after THA and 90-day readmission after TKA, despite preoperative decolonization.…”