Results of an innovative method of intramedullary fixation for displaced 4-part fractures of the proximal humerus in patients younger than 70 years

Background: The management of displaced 4-part fractures of proximal humerus is a challenge, as it is difficult to produce consistently good results with the current methods of fixation. Varus collapse of the head and eventual failure of plate fixation have been reported in up to 45% of cases. We present an innovative method of intramedullary fixation for displaced 4-part proximal humeral fractures. The aim of this study was to present the results of an intramedullary fixation device used for displaced 4-part proximal humeral fractures in patients younger than 70 years. Materials and methods: Fixation was performed with an intramedullary device in 30 patients with an average age of 56 years who had displaced 4-part proximal humeral fractures. The device consists of a circular staple that is impacted in the head and engages into the neck of an intramedullary uncemented stem. The stem has a sleeve that provides the ability to adjust the height and thereby facilitates accurate reduction of the tuberosity with ease. Fracture union was assessed with plain radiographs, and clinical outcomes were assessed using American Shoulder and Elbow Surgeons and Constant scores. Results: Union was achieved in 93.33% of patients and the mean American Shoulder and Elbow Surgeons and Constant scores were 75.2 and 73.97, respectively, at an average follow-up of 25.83 months. None of the patients had tuberosity avulsion, tuberosity nonunion, or resorption. However, 2 patients had humeral head nonunion and 2 had avascular necrosis. Revision surgery was performed in 2 patients (6.67%), because of avascular necrosis in 1 and nonunion in 1. Conclusion: In patients younger than 70 years with displaced 4-part proximal humeral fractures, the described intramedullary device provides a simple and reproducible method of internal fixation with predictable tuberosity union and shoulder function. (c) 2020 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.