64.4 Interpreting the X–rays

The important question in managing a patient’s injured spine, and particularly his injured neck, is to decide if his injury is stable or not. One of the criteria for deciding this is his X–rays. Dislocations should always be considered unstable, so should bending or twisting injuries of the posterior elements of his spine. These include its pedicles, laminae, facets, and ligaments. It is injuries to these posterior elements that make an injury unstable. Compression injuries of a vertebral body are usually stable. In a flexion injury the posterior ligament is particularly liable to be ruptured, and in an extension injury, the anterior one. Both types of injury can damage the intervertebral discs.

The films should be good ones; those from a portable machine are usually useless. Even radiologists have difficulty interpreting X–rays of the spine, so you will probably have difficulty too. The standard views in acute injuries are AP and lateral ones with the patient’s head in its normal position. If these views are normal, take flexion and extension views yourself with the greatest care. They may show one vertebra moving abnormally on another when the standard films are normal. Finally, remember that a normal X–ray does not necessarily mean a normal spine.