Effect of targeted screening and decolonisation for methicillin-sensitive Staphylococcus aureus (MSSA) in elective hip and knee arthroplasty

Background: Nasal and pharyngeal colonization with Staphylococcus aureus (S. aureus) is a major risk factor for postoperative wound infections, particularly following orthopedic procedures. Preoperative targeted decolonisation reduces surgical site infections (SSIs) and is recommended by several national and international guidelines. However, real-world data on the sustained effectiveness of standardized targeted decolonisation programs in orthopedic surgery remain limited. Objective: To evaluate the long-term effectiveness of a standardized preoperative S. aureus screening and targeted octenidine-based decolonisation protocol in reducing postoperative wound infections among orthopedic patients in a secondary care hospital. Methods: In this retrospective single-center interventional cohort study, all patients undergoing elective hip and knee replacement surgery between 2016 and 2023 were screened preoperatively for S. aureus using nasal and throat swabs. Patients testing positive underwent decolonisation with octenidine-based antiseptics. Postoperative infection rates were compared between a pre-intervention period (January 2016 to August 2021) and a post-intervention period (January 2022 to December 2023). A predefined implementation phase (September to December 2021), during which routine screening and decolonisation procedures were established, was excluded from comparative analyses. Results: Among 436 and 511 screened patients prior to elective hip- and knee replacement in 2022 and 2023, respectively, S. aureus carriage was detected in 18%. Implementation of the targeted decolonisation protocol reduced S. aureus-associated wound infections in our reference hospital from 2.89–0.99 per 100 surgeries during the pre-intervention period (2016–2021) to 0.45–0.00 in 2022 and 2023, respectively. Conclusion: Routine preoperative S. aureus screening followed by targeted octenidine-based decolonisation significantly and sustainably reduced postoperative infection rates. These findings provide robust real-world evidence supporting the integration of standardized S. aureus decolonisation protocols into routine orthopedic practice.