Proximal humerus fracture with injury to the axillary artery: A population-based study

BackgroundThe available evidence regarding axillary artery injury as a result of proximal humerus fracture consists of individual case reports or small series. This study used nationally representative data to determine the prevalence and predictors of axillary artery injury secondary to proximal humerus fracture, and to characterise its influence on inpatient mortality, length of stay, cost and discharge disposition.MethodsAn estimated 388,676 inpatients with a proximal humerus fracture were identified in the Nationwide Inpatient Sample between 2002 and 2011, 331 with concomitant axillary artery injury (8.5 per 10,000). Multivariable regression modelling was used to identify independent predictors of axillary artery injury and to assess its relationship with inpatient outcomes.ResultsFactors associated with axillary artery injury were male sex (odds ratio (OR): 1.6, 95% confidence interval (CI): 1.2-2.0), atherosclerosis (OR: 3.7, 95% CI: 2.5-5.4), open fracture (OR: 2.9, 95% CI: 1.9-4.5) and the presence of concomitant injuries, including brachial plexus injury (OR: 109, 95% CI: 79-151), shoulder dislocation (OR: 3.4, 95% CI: 2.0-5.8), scapula fracture (OR: 3.4, 95% CI: 2.1-5.4) and rib fracture (OR: 2.5, 95% CI: 1.6-4.0). Axillary artery injury was associated with increased length of stay, costs and mortality, but it did not affect discharge disposition.ConclusionOur study provides important baseline information regarding the epidemiology of axillary artery injury secondary to proximal humerus fracture. Prompt identification of at-risk patients upon admission might lead to improved diagnosis and management of this vascular injury.Level of EvidencePrognostic level II.