The axial skeleton consists of the bones that form the central axis of the body and includes the skull, sternum, ribs, and vertebra.
As most trauma patients with suspected head injuries are imaged with computed tomography (CT), skull radiographs are now rarely used to diagnose fractures. Fracture types include simple linear (Figure 4-1) and depressed (Figure 4-2A,B). Patients with skull fractures demonstrate an increased risk for intracranial hemorrhage,1,2 and dural laceration can be seen with the depressed type.3
Linear skull fracture. Lateral radiograph of skull shows linear skull fracture in pediatric patient (arrow).
Depressed skull fracture. (A) Lateral radiograph of the skull shows sclerotic double line seen with depressed skull fracture (arrowhead). This finding is often mistaken for artifact. Linear skull fracture is also seen (arrow). (B) Axial CT image of the head showing depression in skull (arrowhead) compared to normal side (white arrow). Linear fracture (black arrow).
Injury to the sternoclavicular and sternomanubrial joints usually occurs after forceful impact and compression. Sternoclavicular dislocation should be suspected on radiographs where the clavicular heads are seen at different craniocaudal positions (Figure 4-3A). Posterior dislocation of the medial clavicle can compromise structures of the thoracic outlet including the great vessels, brachial plexus, and trachea (Figure 4-3B,C).4 Type I sternomanubrial dislocation, where the sternum is displaced posterior to the manubrium, is often identified on physical examination (Figure 4-4). CT can demonstrate any associated mediastinal injuries.5
Disruption of sternoclavicular joint. (A) Frontal chest radiograph shows normally positioned head of right clavicle (arrowheads) compared to superiorly and posteriorly dislocated left clavicular head (arrows). (B) Axial CT image of the clavicles shows normally positioned right clavicular head (arrowhead) and superiorly and posteriorly dislocated left clavicular head (arrow). (C) Axial CT image of the clavicles done in soft tissue algorithm shows superiorly and posteriorly dislocated left clavicular head (arrow) and compression of left subclavian vessels (arrowhead).
Sternomanubrial dislocation. Sagittal CT reformat of the sternum shows type I sternomanubrial dislocation occurring at the sternomanubrial joint (arrow). S, sternum; M, manubrium.
Rib fractures are a frequent finding on chest radiographs obtained on admission to the trauma emergency department or on the CT scan done to evaluate chest, abdomen, ...