Olecranon fractures typically occur in conjunction with other elbow injuries, notably a radial neck fracture or dislocation of the radial head (Monteggia variant), or lateral condyle fracture Comparative views may be helpful in distinguishing the olecranon growth plate from a fracture A missed fracture of the olecranon epiphysis can lead to a fixed flexion deformity resulting in significant morbidity in adulthood The mechanism of an isolated olecranon fracture is hypothesized to be a sudden flexion of the elbow when the triceps is strongly contracted (essentially an avulsion injury), direct trauma, or stress fracture from repeated throwing activity Physical findings range from localized swelling to a marked hemarthrosis with weak or absent elbow extension Nondisplaced fractures may be somewhat difficult to discern on the standard anteroposterior and lateral radiographs; however, the presence of an abnormal fat pad should be viewed as presumptive evidence of a bony injury ( Fig 111.22 ) Olecranon fractures of