Does clavicular shortening after nonoperative treatment of midshaft fractures affect shoulder function? A systematic review

INTRODUCTION: Clavicular shortening due to non-anatomical healing of displaced clavicular fractures is believed to have a negative effect on shoulder function after recovery. The evidence for this, however, is equivocal. This review aimed to systematically evaluate the available literature to determine whether the current beliefs about clavicular shortening can be substantiated. MATERIALS AND METHODS: This systematic review was performed following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. PubMed, EMBASE, Web of Science and the Clinical Trial Registry were searched to identify all studies published in English that evaluated the association between clavicular shortening and shoulder function in patients aged ≥16 years with a nonoperatively treated, displaced midshaft clavicular fracture. Relevant data from the selected studies was extracted and summarized. Risk of bias of the included studies was assessed using the MINORS instrument. RESULTS: Six studies, of which five were retrospective, were included in this review analyzing a total of 379 patients. Due to heterogeneity in methods and reporting across studies, a pooled analysis of the results was not feasible. No clear associations were found between shortening and shoulder function scores (DASH and Constant score) or arm strength in each of the included studies. CONCLUSION: The existing evidence to date does not allow for a valid conclusion regarding the influence of shortening on shoulder function after union of nonoperatively treated midshaft clavicular fractures. Shortening alone is currently not an evidence-based indication to operate for the goal of functional improvement. Well-powered prospective comparative studies are needed to draw firm conclusions. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00402-017-2734-7) contains supplementary material, which is available to authorized users.