RESUMEN
PURPOSE: To evaluate the prevalence of Cutibacterium acnes in the shoulder region and to analyze changes in C acnes contamination during shoulder arthroscopy, as well as to investigate the influence of sex and type of arthroscopic surgery on those parameters. METHODS: Forty-eight consecutive patients undergoing reconstructive or non-reconstructive shoulder arthroscopy, after hair removal with a medical clipper, routine antibiotic prophylaxis, and skin preparation with an alcohol-based skin disinfectant, were prospectively enrolled in this study. The shoulder was divided into 4 regions of interest (anterior, medial, posterior, and axilla). Skin swabs were taken from each region at 3 time points (preoperatively before and after skin preparation, and at the conclusion of surgery), cultured for 21 days, and analyzed for the prevalence of C acnes. RESULTS: The rate of C acnes-positive skin cultures was significantly increased at the end of surgery compared with preoperatively before (44.3% vs 27.6%, P < .001) and after (44.3% vs 31.3%, P = .001) skin preparation. No reduction in C acnes was observed with preoperative skin preparation (27.6% vs 31.3%, P = .401). At the end of shoulder arthroscopy, 64.6% of patients showed at least 1 culture positive for C acnes. The C acnes prevalence was significantly higher in male patients (48.3%) than female patients (20.1%, P < .001), at all time points (P < .016), and in all regions of interest (P < .001) except the axilla. No differences in the prevalence of C acnes were found between non-reconstructive and reconstructive procedures. CONCLUSIONS: Skin contamination with C acnes around the shoulder increased significantly from before and after skin preparation to the conclusion of surgery in patients undergoing shoulder arthroscopy despite perioperative preventive measures. LEVEL OF EVIDENCE: Level IV, therapeutic case series.