Inflammatory biomarkers predict Cutibacterium acnes detection at the portal area during arthroscopic shoulder surgery

Cutibacterium acnes (C. acnes), a gram-positive bacterium commonly found in the pilosebaceous glands of the shoulder, represents a significant source of infection following shoulder surgery. Identifying patients at higher risk for bacterial contamination prior to surgery could facilitate the implementation of enhanced prophylactic measures. The objective of this study was to identify biomarkers and related factors that predict the detection of C. acnes at the portal of arthroscopic shoulder surgery.

This study included 110 patients undergoing arthroscopic shoulder surgery. Swab cultures were obtained from the arthroscopic portal approximately 1 h post-creation to assess for the presence of C. acnes. Preoperative inflammatory biomarkers, including the neutrophil-to-lymphocyte ratio (NLR) and monocyte-to-lymphocyte ratio (MLR), were evaluated in relation to bacterial detection.

C. acnes was identified in 18.2 % of patients, with all positive cases exclusively observed in male patients. Both NLR and MLR were significantly elevated in patients with positive C. acnes cultures. Receiver operating characteristic (ROC) curve analysis identified optimal threshold values of 1.73 for NLR and 0.17 for MLR in predicting C. acnes detection.

Elevated preoperative NLR and MLR are associated with the intraoperative detection of C. acnes at the arthroscopic portal site. These readily available biomarkers may help identify patients at increased risk for bacterial contamination, informing preoperative prophylactic protocols.