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

AIMS: 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 Cutibacterium acnes.

METHODS

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.

RESULTS

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). C. acnes 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).

CONCLUSION

Combining disinfection of the subcutaneous tissue after incision with preoperative application of benzoyl peroxide reduced the presence of C. acnes during surgery. These results suggest that the triple prevention protocol may be effective in reducing C. acnes infections after both arthroscopic and open surgery.