Fracture of the Spinous Processes

Spinous process fractures are most readily seen on the lateral view. On the anteroposterior view they are recognized only with difficulty, unless especially sought.

The radiographic diagnosis of fractures of the spinous processes of the seventh cervical and the first thoracic vertebra can be made on the preliminary anteroposterior view of the cervical and upper thoracic spine. The fracture can be identified by the malalignment and downward displacement of the outer end of the spinous process. On the x-ray film, a double shadow is seen. A smooth, crescentic area of decreased density represents the fractured base of the spinous process, and a denser shadow lying in the soft tissues, slightly caudad to the base of the spinous process, represents the displaced tip. Patients who have received a severe head or neck injury usually report to the hospital with the head held either in hyperflexion or hyperextension. On the routine lateral view of the neck it is difficult to see the spinous processes of C-7 and T-l because of the superimposition of the shadows produced by the bone and soft tissues of the shoulder girdle. Under such circumstances, the anteroposterior view of the spine should be sufficient to make a diagnosis of fracture.

During the past twelve months this x-ray sign of fracture of the spinous processes of the lower cervical and upper thoracic vertebrae has been observed in three cases. In two of these the diagnosis of fracture of the spinous process of C-7 was made on the preliminary anteroposterior view. In the third case, here reported, the fracture involved the spinous process of T-l.

The films of more than two hundred spines have been reviewed, and the sign was recognized only in those cases in which a fracture was present. The identification of the fracture on the preliminary anteroposterior film can serve as a guide and warning that other components of the cervical or thoracic vertebrae may be fractured.

The following case illustrates the ease with which one can identify a fracture of the spinous process of the upper thoracic vertebra on the routine anteroposterior view.

An 18-year old white male was admitted to the hospital because of severe pain in the posterior neck region. There was a history of a direct blow to the neck. Preliminary anteroposterior and lateral views of the neck and upper dorsal spine were taken on admission. On the anteroposterior view a fracture of the spinous process of T-l with caudad displacement of the outer fragment was seen. A crescentic radiolucent area, representing the base of the spinous process, and a denser shadow of bone seen slightly caudad to the translucent area, representing the fractured tip of the spinous process, were seen. It was difficult to visualize the spinous process of T-l on the routine lateral view. Later, with more relaxation of the muscles of the neck, and with the neck hyperflexed, a second lateral view was taken.