Avascular necrosis of the capitellum after surgical treatment of a coronal shear fracture of the distal humerus: A case report

Introduction and importance: Coronal shear fractures of the distal humerus are rare and are expected to have a high incidence of avascular necrosis (AVN) due to the avascular nature of the capitellar bone fragment and limited soft tissue attachment. However, according to the literature published thus far, AVN is infrequently reported, and some studies suggest that it does not have a significant impact on clinical outcomes. Case presentation: Two female patients, one aged 72 and the other 70, presented with coronal shear fractures of distal humerus. Both patients were diagnosed with AVN of the capitellum 7 and 10 months after undergoing open reduction and internal fixation. One patient underwent hardware removal, while the other patient declined due to the absence of discomfort. However, at their final follow-up, both patients exhibited good clinical results. Clinical discussion: The occurrence of AVN may be related to the severity of the initial injury, including posterior comminution. While some studies suggest that AVN of the capitellum may not affect clinical outcomes, hardware removal may be required in cases where there is intra-articular protrusion of the hardware. Conclusion: Although AVN is a rare occurrence, even when it does occur, it may not significantly affect clinical outcomes. In this study, AVN may be associated with initial injury severity, and surgical treatment may make it possible to develop AVN. Moreover, considering the timing of the occurrence of AVN, it is believed that a close follow-up of more than one year will be required.