Impact of smoking on structural failure after arthroscopic rotator cuff repair: a systematic review and meta-analysis.
BACKGROUND: Rotator cuff tears cause significant shoulder pain and functional limitation. Arthroscopic rotator cuff repair improves symptoms, yet structural failure rates remain substantial. Smoking may impair tendon-to-bone healing, but clinical studies report mixed findings due to heterogeneous methodology. Therefore, a systematic synthesis of imaging-confirmed outcomes is needed to clarify the association between smoking and structural failure after arthroscopic rotator cuff repair. METHODS: This review followed PRISMA 2020 and was registered in PROSPERO (CRD420251246197). PubMed, Embase, Scopus, Web of Science, and the Cochrane Library were searched from inception to 12 December 2025. Comparative clinical studies of adults undergoing arthroscopic rotator cuff repair that reported imaging-confirmed structural integrity (magnetic resonance imaging or ultrasonography) at ≥6 months were included. Two reviewers independently screened studies, extracted data, and assessed quality using the Newcastle-Ottawa Scale. The primary outcome (structural failure) was pooled as risk ratios using a random-effects model with the restricted maximum likelihood estimator and Hartung-Knapp adjustment. Secondary continuous outcomes were synthesized using Bayesian random-effects models; subgroup, sensitivity, and meta-regression analyses explored heterogeneity. RESULTS: Ten cohort studies (1,683 shoulders) were included. Smoking was associated with a higher risk of imaging-confirmed structural failure (risk ratio 1.53; 95% confidence interval 1.13-2.08; P = .011) with low heterogeneity (I2 = 24.7%). Subgroup and sensitivity analyses supported robustness, with no evidence of effect modification by region, follow-up duration, tear size, or smoking definition. Meta-regression showed no significant influence of age, smoking prevalence, or diabetes prevalence on the pooled effect. Secondary outcomes (3 studies) suggested slightly lower postoperative American Shoulder and Elbow Surgeons scores among smokers, while visual analog scale pain scores and forward flexion showed no clear between-group differences. No publication-bias signals were detected for the primary outcome. CONCLUSION: Smoking is associated with a higher risk of imaging-confirmed structural failure after arthroscopic rotator cuff repair. Functional outcomes were broadly similar between groups, with only a small, likely clinically negligible reduction in American Shoulder and Elbow Surgeons scores among smokers. These findings support careful smoking history assessment and perioperative risk modification, including smoking cessation strategies.