摘要

Objectives: To evaluate the efficacy, safety, and patient-reported outcomes of BoNT-A for surgical and traumatic scars, and to determine how timing, dose and anatomical site influence clinical outcomes. Introduction: Hypertrophic and unesthetic scarring after surgery or trauma is a major functional and aesthetic concern. Conventional strategies such as silicone or corticosteroids lack consistent benefit and clear protocols. Botulinum toxin A (BoNT-A) has emerged as an adjunct through muscle relaxation and fibroblast modulation. Early studies suggest improved scar quality but are limited by small samples, facial bias, and heterogeneity. This review is the first to evaluate BoNT-A across scar types with focus on timing, dose and anatomical site as clinical modifiers. Materials / method: This review followed PRISMA 2020 and was registered in PROSPERO (CRD420251108992). MEDLINE, Embase, Cochrane Library, and ClinicalTrials.gov were searched through September 2025. Eligible studies were randomized controlled trials or prospective comparative designs evaluating perioperative or early postoperative BoNT-A in adults. Primary outcomes were scar quality using validated scales (VSS, POSAS, mSBSES). Secondary outcomes included satisfaction, pain, pruritus, and adverse events. Timing, dose, and anatomical site were assessed as effect modifiers. Results: Sixteen studies with 456 patients were included. BoNT-A improved scar quality at 3—6 months, with 6/7 VSS and 4/5 mSBSES trials showing benefit, and 5/7 reporting narrower scars. POSAS showed consistent improvement in observer domains, though patient scores were more variable. Satisfaction was higher with reduced pain and pruritus and no serous adverse events. Subgroup analyses found superior outcomes with early use (intraoperative or ≤ 7 days), higher dosing in high-tension sites, and greatest efficacy in cosmetically stressed regions, while effects in low-tension areas were less pronounced. Conclusion: BoNT-A improves scar quality and patient experience with a favorable safety profile. Timing, dose, and anatomical site are modifiable factors that optimize efficacy, making BoNT-A relevant to both aesthetic and reconstructive practice. Standardized protocols will be essential to guide broader clinical adoption.