The effects of smoking on clinical and structural outcomes after rotator cuff repair: a systematic review and meta-analysis.

BACKGROUND: Several factors have been reported to adversely affect clinical and structural outcomes after rotator cuff repair (RCR). However, the effects of smoking on rotator cuff healing and clinical outcomes remain controversial. The purpose of this study was to compare the clinical and structural outcomes after RCR between smokers and nonsmokers. We hypothesized that there would be no significant difference in the clinical scores after RCR and that smoking would be associated with a significantly increased risk of retear and reoperation. METHODS: This systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines using the PubMed, Cochrane Library, and Embase databases. We included only articles in which patients underwent arthroscopic and open RCR, the clinical outcome scores were reported for smokers and nonsmokers, and the number of rotator cuff retears and reoperations were reported. Data relevant to this study were extracted and statistically analyzed. We used the Newcastle-Ottawa Scale to assess the risk of bias in each study and calculated the I2 value to quantify the effect of heterogeneity. RESULTS: Fourteen eligible articles were identified, with 73,817 participants (8553 smokers and 65,264 nonsmokers). The meta-analysis demonstrated that there were no significant differences in the American Shoulder and Elbow Surgeons score (P = .10), Simple Shoulder Test score (P = .19), University of California-Los Angeles score (P = .09), or visual analog scale score (P = .19) between smokers and nonsmokers after surgery, but the Constant score was significantly lower (P = .005) for smokers. Smoking was significantly associated with an increased risk of retear (P = .002; risk ratio, 2.06 [95% confidence interval, 1.30-3.28]; I2 = 31%) and reoperation (P < .001; risk ratio, 1.29 [95% confidence interval, 1.20-1.40]; I2 = 36%) in patients after RCR. CONCLUSION: Besides the Constant score, which was lower in smokers, there were no significant differences in the clinical scores after RCR between smokers and nonsmokers. However, smoking was associated with a significantly increased risk of retear and reoperation.