Preoperative benzoyl peroxide 5% reduces early Cutibacterium acnes–related postoperative spinal implant infections: a quasi-experimental study

AIMS: Postoperative spinal implant infections (PSIIs) are serious complications in spinal deformity surgery, with Cutibacterium acnes representing a frequent pathogen. This study aimed to evaluate whether adding of preoperative topical benzoyl peroxide (BPO) 5% to standard antibiotic prophylaxis could reduce early C. acnes-related and overall PSIIs. METHODS: A retrospective quasi-experimental study was performed at a tertiary spinal surgery center, including two sequential 12-month cohorts of patients undergoing corrective spinal surgery. The control group received standard intravenous antibiotic prophylaxis, while the intervention group received additional topical BPO 5% applied twice daily for three days before surgery. The primary outcome was the incidence of early C. acnes PSIIs within 90 days; the secondary outcome was the incidence of overall early PSIIs. RESULTS: A total of 160 patients were analyzed (80 per group). Baseline demographic and surgical characteristics were comparable. Early PSIIs occurred in 12 patients (7.5% overall). The incidence was significantly lower in the BPO group compared with the standard care group (2.5% vs. 12.5%, p = 0.036). C. acnes-related PSIIs occurred in one patient (1.3%) in the BPO group and six patients (7.5%) in the control group, representing a numerical reduction that did not reach statistical significance (HR:0.182[95%CI:0.022;1.52]). Cox regression showed lower hazard of overall infection in the BPO group compared with the SoC group (HR:0.21[95%CI:0.046;0.960]), although based on a small number of infections. CONCLUSION: Preoperative application of BPO 5%, in combination with standard antibiotic prophylaxis, was associated with a significant reduction in overall early PSIIs and with a clinically meaningful but statistically non-significant reduction in C. acnes-related PSIIs. These findings should be considered hypothesis-generating and require confirmation in larger prospective studies. This simple, low-cost, and readily implementable adjunct may represent an effective addition to infection-prevention strategies in spinal surgery.