Factors affecting the incidence of aseptic nonunion after surgical fixation of humeral diaphyseal fracture

Background Although aseptic nonunion of humeral diaphyseal fracture is rare, it often is debilitating for the patient. Treatment is challenging for the surgeon when nonunion occurs. The purpose of this study was to analyze and identify independent risk factors for aseptic nonunion among patients with humeral diaphyseal fracture undergoing surgical fixation. Methods The medical records of all humeral diaphyseal fracture patients who underwent surgical fixation from January 2005 to January 2011 were reviewed to identify those who developed aseptic nonunion. We performed univariate and multivariate logistic regression to identify independent associations of potential risk factors for aseptic nonunion among patients with surgical humeral diaphyseal fracture. Results A total of 686 patients were identified, with 659 meeting our inclusion criteria. Among these 659 cases there were 24 cases of septic nonunion, an incidence of 3.6 %. The patients were followed for 9-24 months, with an average follow-up period of 14.8 months. In the final regression model, advanced age (odds ratio, 1.09; 95 % CI: 1.03-1.14, P = 0.001), smoking (odds ratio, 5.34; 95 % CI: 1.05-27.00, P = 0.043), use of NSAIDs (odds ratio, 2.51; 95 % CI: 1.80-3.50, P < 0.001), and ASA score (odds ratio, 3.04; 95 % CI: 1.06-8.74, P = 0.039) were risk factors for aseptic nonunion of humeral diaphyseal fracture after surgical fixation. Conclusions This analysis confirms advanced age, smoking, use of NSAIDs, and ASA score were related to an increased risk of aseptic nonunion of humeral diaphyseal fracture after surgical fixation. Patients who have the risk factors identified in this study should be counseled about the possibility of aseptic nonunion occurring after surgical fixation.