A 41-year-old man was brought to the ED following a motor vehicle
collision in which he was an unrestrained driver whose vehicle hit
a roadway median divider. The automobile driver’s air bag deployed.
At the scene, the patient was confused and “oriented times
two.” Upon his arrival in the ED, his mental status was
normal and he admitted to having had “a few beers.” He
complained of lower back and neck pain.
The patient was hemodynamically stable. The only evident trauma
was a left parietal scalp laceration and hematoma. His neurological
examination was normal.
The chest and pelvis radiographs were negative for an acute injury.
The cervical spine radiographs are shown in Figure 1.
- Are there any abnormalities?
Note: Loss of anterior vertebral body
height at C4 is not an acute fracture. However, there is a second finding
that represents an unstable cervical spine injury.
(Arrow = windshield
glass lying next to the patient’s scalp.)
All seven vertebrae are visible (Figure 2). The patient’s
position is slightly rotated, as evident by the lack of perfect
overlap of the left and right articular facets at each vertebra.
The overall alignment
of the vertebral bodies and spinolaminar
line appears normal. The intervertebral disk spaces and the spaces between the
spinous processes are uniform.
The prevertebral soft tissues are
less than 5 mm at C1, C2, and C3. However, close examination of
the contour of the prevertebral soft
tissue reveals a slight focal convexity (bulge) anterior to the
base of the dens (white arrowhead).
Examination of the bones of the lower
cervical spine reveals narrowing
of the anterior aspect of the C4 vertebral body (arrow,Figure
2). However, based on the radiographic findings and subsequent evaluation
with CT and flexion/extension views, this represents an
old injury rather than an acute fracture.
When examining the bones of the cervicocranium, several
radiographic landmarks should be noted. These include the predental
space, the posterior arch of C1, the dens, the C2 vertebral body,
and the posterior arch of C2 (Figure 3).
Radiographic landmarks of the cervicocranium.
A distinctive radiographic landmark overlies the body of C2—the “ring of C2” (...