The posterior vertebral body line: importance in the detection of burst fractures.

A review of the lateral radiographs and CT studies of 114 patients with burst fractures, 46 patients with combined injuries in whom bursting was a major component, and 82 patients with simple anterior compression fractures was performed to evaluate the integrity of the posterior vertebral body margin. This structure normally produces a single or bifid vertical line on the lateral radiograph. Disruption, displacement, or rotation of this line was found in all 114 patients with "pure" burst fractures. These abnormalities were also present in 36 of the 46 patients with combined burst injuries. In all patients with simple compression fracture, flexion, distraction or dislocation, and extension injuries, the line was normal. CT studies showed these abnormalities to be the result of retropulsion of one or more bone fragments from the posterior margin of the vertebral body. Disruptive abnormalities of the posterior vertebral body line are reliable plain-film signs that a burst fracture has occurred and that compromise of the vertebral canal and subarachnoid space is present.