Low and high body mass index and lower numbers of screws in the articular segment are risk factors for non-union of distal humeral fractures in the elderly: A multi-center retrospective study (TRON study)

Abstract

Background Distal humerus fracture in the elderly is a challenging fracture for orthopedic surgeons. Non-union is one of the serious complications of distal humerus fracture after surgery. This retrospective multicenter study aimed to estimate the incidence of distal humeral non-union after open reduction and internal fixation, determine factors related to non-union, and compare the postoperative results of cases with non-union to cases with the union. Methods Among 423 patients diagnosed with distal humeral fracture and who were treated by surgical therapy in 2010–2020 from our database called TRON. Only 190 subjects met the inclusion criteria. We performed a logistic regression analysis with the presence of non-union as the response variable to examine risk factors. We compare the Mayo Elbow Performance Scores of cases with non-union to cases with the union. Results Non-union occurred after surgery in 15 patients (7.9%). The logistic regression analysis showed that body mass index<20 kg/m2 and ≥25 kg/m2, and ≤3 screws in the articular segment were significant explanatory factors for non-union (odds ratio 10.4 and 47.8, respectively). The Mayo Elbow Performance Scores were significantly worse in patients with non-union. Discussion Low and high body mass index and three or fewer screws in the articular segment might be risk factors for non-union of distal humerus fracture in the elderly. Non-union is associated with poor clinical outcomes.