injuries poisoning
Distal Humeral Fractures
Diagnosis of Distal Humeral Fractures
Anteroposterior and lateral x-rays A fracture line may not be visible, but other x-ray findings may suggest fracture. They include Posterior fat pad Anterior fat pad (sail sign) Abnormal anterior humeral line Abnormal radiocapitellar line Aposterior fat padon a true lateral x-ray of the elbow is always abnormal; this finding is specific for joint effusion but not highly sensitive. Adisplaced anterior fat padmay indicate joint effusion but is not specific. However, if a posterior fat pad is seen or if a large anterior fat pad (sail sign) is present, an occult fracture should be assumed and should be treated as such. Anterior humeral line and radiocapitellar line None Theradiocapitellar lineis a line drawn through the midshaft of the radius on a true lateral x-ray of the elbow; normally, it bisects the capitellum. If it does not, an occult fracture should be suspected. If findings in children are compatible with a distal humeral fracture, review x-rays closely for evidence of occult fracture (eg, a posterior fat pad, abnormalities in the anterior humeral or radiocapitellar line). If findings in children are compatible with a distal humeral fracture, x-rays should be reviewed closely for evidence of occult fracture (eg, a posterior fat pad, abnormalities in the anterior humeral or radiocapitellar line). A complete neurovascular examination is done if a fracture is suspected. Particular attention should be paid to the median, radial, and ulnar nerves. Distal pulses should be compared with those of the opposite limb, particularly if ecchymoses or enlarging swelling (which suggest brachial artery injury) are present on the anterior medial forearm. Normally, the anterior humeral line, which is drawn along the anterior border of the humerus on a lateral x-ray, transects the middle of the capitellum. If the line transects none or only the anterior part of the capitellum, a distal humeral fracture with posterior displacement may be present. The radiocapitellar line, which is drawn through the midshaft of the radius, normally bisects the capitellum. If it does not, an occult fracture should be suspected. The anterior humeral line and radiocapitellar line are normal. However, an anterior fat pad is present, suggesting a joint effusion. Image courtesy of Danielle Campagne, MD. A posterior fat pad is always abnormal. Also on this x-ray, the anterior humeral line does not transect the middle of the capitellum. Image courtesy of Danielle Campagne, MD. 