Benzoyl peroxide combined with subcutaneous iodine reduces Cutibacterium acnes presence during shoulder surgery : a three-armed, single-blinded, randomized controlled trial.

Abstract

The purpose of this study was to assess the effect of combined preoperative benzoyl peroxide application and subcutaneous povidone-iodine (PV-I) disinfection, in addition to standard PV-I disinfection of the skin, on intraoperative cultures of <i>Cutibacterium acnes</i>. All patients undergoing arthroscopic or open shoulder surgery were eligible for inclusion. Patients were randomized into one of three groups: control (standard disinfection of the skin with PV-I), double prevention (disinfection of the skin and subcutaneous tissue with PV-I after incision for 60 seconds), and triple prevention (application of benzoyl peroxide during the three days before surgery, disinfection of the skin with PV-I, and disinfection of the subcutaneous tissue with PV-I after incision for 60 seconds). Cultures were taken of the tissue layers, equipment, and the surgeon's gloves. A sample size of 156 patients was calculated. Culture positivity was compared between the groups, with the intra-articular and deep muscular culture as the primary outcome. A total of 156 patients (median age 58 years (IQR 20 to 85), with 61 patients (39%) being female) were included. The intra-articular cultures were positive in 16 patients (32%) in the control group, 11 (21%) in the double prevention group, and five (10%) in the triple prevention group (p = 0.031). <i>C. acnes</i> presence in the muscular layer was 21 (42%) in the control group, 17 (33%) in the double prevention group, and seven (13%) in the triple prevention group (p = 0.0052). The median number of positive cultures was one in the control group (IQR 0 to 5), one in the double prevention group (IQR 0 to 3.75), and zero in the triple prevention group (IQR 0 to 2; p = 0.082). Combining disinfection of the subcutaneous tissue after incision with preoperative application of benzoyl peroxide reduced the presence of <i>C. acnes</i> during surgery. These results suggest that the triple prevention protocol may be effective in reducing <i>C. acnes</i> infections after both arthroscopic and open surgery.