PA radiograph of the chest (Fig. 90A) reveals a left apical pneumothorax, a small left pleural effusion, and a left lateral ninth rib fracture. Figure 90B is a magnified PA view of the left apical pneumothorax shown in Figure 90A. AP view of the lower ribs (Fig. 90C) again demonstrates the minimally displaced left lateral ninth rib fracture and small left pleural effusion.

Pneumothorax, hemothorax, traumatic rib fracture, stress rib fracture, pathologic rib fracture.

Rib fractures are the most common thoracic injury; they occur in 10% of total traumatic injuries overall and in nearly 40% of severe blunt trauma cases (motor vehicle collisions, falls, industrial accidents).1 Rib fractures occur in isolation only 6% to 13% of the time.2 Rib fractures are uncommon in penetrating trauma. The fifth to ninth ribs are the most frequently fractured. Fractures of the superior ribs are usually only seen in highenergy trauma; considerable force is required to break these ribs because of shielding by the scapula and clavicle. Fracture of the inferior ribs may be less common due to being less rigidly fixed. Rib fractures may also cause secondary complications including pneumothorax, hemothorax, pulmonary contusion, pulmonary laceration, and pain leading to abnormal pulmonary mechanics. First and second rib fractures are associated with great arch vascular and brachial plexus injuries. Lower rib fractures are associated with lacerations of the liver, spleen, and kidneys. Overall trauma morbidity and mortality correlates with increasing number of rib fractures, particularly in the elderly, given lower cardiopulmonary reserve.