Standard views include AP (full extension) and lateral (90° bending) radiographs of the elbow. When a fracture line is not visible but a joint effusion is present, there is an approximately 50% incidence of occult fracture. A joint effusion may be suggested when the anterior sail sign has an inferior concave margin. The anterior fat triangle is a normal finding when the inferior margin has a slender draped appearance over the anterior humeral line. A posterior fat pad sign should always be considered abnormal, irrespective of the shape of the inferior aspect of the triangle.
Additional landmarks to consider during the review of an elbow radiograph when an obvious fracture is not present include the anterior humeral line and the radiocapitellar line. The anterior humeral line should bisect the middle third of the capitellum on the lateral view. If the anterior humeral line does not bisect the middle third of the capitellum, a displaced occult supracondylar fracture should be suspected. The radiocapitellar line is a line drawn along the radial shaft to the capitellum. The radiocapitellar line should line up with the capitellum on all views, including AP, oblique, and lateral projections. If the radiocapitellar line is not maintained, a radial head dislocation should be considered.
The most common pediatric elbow fracture is a supracondylar fracture. The majority of pediatric supracondylar fractures are extra-articular. The Gartland classification separates these fractures into three types: type 1 nondisplaced, type 2 displaced with intact posterior cortex, and type 3 displaced with no cortical contact.
The second most common pediatric elbow fracture is a lateral condylar fracture. These fractures should be considered Salter–Harris IV fractures until proven otherwise.
The third most common pediatric elbow fracture is the medial epicondylar avulsion fracture. These by definition are Salter–Harris I fractures. These fractures occur due to an avulsion injury related to the common flexor muscle origin from the medial epicondyle. A final point to remember is that the medial epicondyle ossification appears before the trochlear ossification. Therefore, if a trochlear ossification appears to be present but the medial epicondylar ossification center has not yet appeared, a displaced medial epicondylar avulsion fracture should be considered.
In pediatric patients with pain or swelling to the elbow, it should be assumed that a fracture is present. Prior to splinting, one should ensure that the patient is neurovascularly intact. The brachial artery can be injured when the fracture is displaced posteriorly. Injury to the anterior interosseous branch of the median nerve may also occur and would lead to inability to touch the thumb to the index finger and make an “OK” sign.
For supracondylar fractures with no displacement, patients can be splinted with a posterior splint with an A-frame. Fractures with displacement and condyle fractures often require orthopaedic consultation and surgical fixation.