epicondyle (4 to years old), but this injury is not typically intra-articular ( Fig 111.21 ) Clinically, children often present with the elbow held in flexion and with swelling and tenderness localized to the medial aspect of the elbow, with valgus instability (most readily demonstrated by stress radiographs) Oblique radiograph views in addition to stress and comparison views may be needed for diagnosis Additional imaging with MRI examination may prove useful in defining the extent of the injury Nondisplaced fractures are managed in the emergency setting with casting or posterior splinting with the elbow in flexion and neutral position, or pronation for weeks with outpatient orthopedic follow-up Indications for surgical management are widely debated and evidence is limited except for cases of incarcerated fracture fragment within the joint Orthopedic consultation is advised in patients with neuropathy, valgus instability, or fracture fragment displacement >2 mm FIGURE 111.21 Displaced fracture of the medial epicondyle in an 8-year-old girl (arrow ) Distal Humerus Physeal Fractures CLINICAL PEARLS AND PITFALLS Fractures of the distal humeral physis in children under the age of years, and especially infants under the age of year, should raise concern for possible abuse Radiographic diagnosis of humerus physeal fractures is difficult as the distal humerus and proximal radius and ulna have not yet ossified To distinguish distal humeral physeal separation from elbow dislocation, one should note that displacement of the proximal radius and ulna is usually posterior and medial in the former With dislocation, the proximal radius and ulna are typically displaced posterolaterally, and the relationship between proximal radius and lateral condyle epiphysis is disrupted Separation of the distal humerus physis is an infrequently seen elbow injury in the pediatric ED and the diagnosis is frequently missed leading to delays in diagnosis Most injuries involving the entire distal humeral physis occur before age Recognition is both difficult and important, especially in infants, in whom this particular injury is often the result of physical abuse The proposed mechanism in abused children is forceful twisting of the arm that shears off the distal epiphysis Elbow swelling, pain, and disuse of the extremity, but without significant deformity, in the setting of a FOOSH are the usual history and examination With significant displacement, the appearance may mimic that of an elbow dislocation Dislocations more commonly occur in early adolescence than in children less than years old Radiographic diagnosis requires recognition of subtle displacement and may necessitate comparison views In the normal relationship, the shaft of the ulna should align with the shaft of the humerus on the anteroposterior view, whereas the ulna will be medial on the AP view compared with this injury With clinical concern, ultrasound may be a useful adjunct Given the frequent need for reduction and pinning, all suspected epiphyseal separations of the distal humerus merit immediate orthopedic referral MRI or ultrasound studies may be necessary to define the extent of damage to the cartilaginous structures The risk of avascular necrosis and growth disturbance increases with delay in diagnosis Olecranon Fractures CLINICAL PEARLS AND PITFALLS 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