Direct trauma or fall on an outstretched hand may result in elbow fractures. The patient may be unable to extend the elbow and have pain on supination/pronation. AP, lateral, and oblique radiographic views can visualize most fractures. The radial head should be aligned with the capitellum on all views. The anterior fat pad may be seen on normal radiographs, but displacement anteriorly and superiorly (sail sign) suggests effusion or hemarthrosis. The posterior fat pad is not normally visualized, but if seen is indicative of effusion or hemarthrosis.
Radiographic Elbow Relationships. In lateral views, the anterior humeral line (1-2) should bisect the middle third of the capitellum. The radiocapitellar line (drawn through the center of the radius, 3-4) should also pass through the center of the capitellum. Disruption of these relationships may indicate fracture.
Supracondylar fractures most often occur in pediatric patients. Neurovascular insult occurs in 7%, with the anterior interosseous nerve most commonly injured. This can be checked by having the patient make an “ok” sign. This neuropraxia usually resolves in 6 months. Arterial injury to the brachial artery occurs in 5% to 20%, with less than 1% of these complicated by compartment syndrome. Arteriography is indicated if the radial pulse is decreased after reduction; however, it should not delay operative evaluation.
Type I Supracondylar Fracture. This radiograph shows both a pronounced anterior fat pad (sail sign) and posterior fat pad indicative of a supracondylar fracture. (Photo contributor: Alan B. Storrow, MD.)
Type II Supracondylar Fracture. (A) Clinical picture with marked soft tissue swelling in a child with a history of falling on an outstretched arm. (B and C) AP and lateral views of the elbow, demonstrating a distal humerus fracture with posterior displacement of the medial and lateral condyles. (Reproduced with permission from Shah BR, Lucchesi M. Atlas of Pediatric Emergency Medicine. New York, NY: McGraw Hill; 2006.)
Capitellum fractures represent less than 1% of adult elbow fractures and typically occur following high-energy trauma. These are difficult to diagnose radiographically and may require a computed tomography (CT) scan.
Management and Disposition
Treatment is influenced by stability of the fracture pattern as well as associated neurovascular injuries. If neurovascular compromise exists, the physician may need to apply forearm traction to reestablish distal pulses. If the pulse is not restored with traction, emergent operative intervention for brachial artery exploration or fasciotomy is indicated. In children, nondisplaced fractures (type I) can be splinted in 90 degrees of flexion. Angulated or displaced fractures (type II and III) often require operative intervention.