Influence of smoking on the healing of conservatively treated displaced midshaft clavicle fractures A SYSTEMATIC REVIEW AND META- ANALYSIS

Aims Tobacco, in addition to being one of the greatest public health threats facing our world, is believed to have deleterious effects on bone metabolism and especially on bone healing. It has been described in the literature that patients who smoke are approximately twice as likely to develop a nonunion following a non-specific bone fracture. For clavicle fractures, this risk is unclear, as is the impact that such a complication might have on the initial man-agement of these fractures.Methods A systematic review and meta-analysis were performed for conservatively treated dis-placed midshaft clavicle fractures. Embase, PubMed, and Cochrane Central Register of Controlled Trials (via Cochrane Library) were searched from inception to 12 May 2022, with supplementary searches in Open Grey, ClinicalTrials. gov, ProQuest Dissertations & Theses, and Google Scholar. The searches were performed without limits for publication date or languages.Results The meta-analysis included eight studies, 2,285 observations, and 304 events (nonunion). The random effects model predicted a pooled risk ratio (RR) of 3.68 (95% confidence inter- val 1.87 to 7.23), which can be considered significant (p = 0.003). It indicates that smoking more than triples the risk of nonunion when a fracture is treated conservatively.Conclusion Smoking confers a RR of 3.68 for developing a nonunion in patients with a displaced mid-dle third clavicle fracture treated conservatively. We know that most patients with pseudarthrosis will have pain and a poor functional outcome. Therefore, patients should be informed of the significantly higher risks of nonunion and offered smoking cessation ef- forts and counselling. Moreover, surgery should be considered for any patient who smokes with this type of fracture.

Automated summary

Smoking increases the risk of nonunion in patients with conservatively treated clavicle fractures. It is important to inform patients about the higher risks of nonunion associated with smoking and provide smoking cessation support. Surgery should be considered for smokers with this type of fracture.