ABCS In Cervical Spine Injuries

A cervical spine injury is unlikely in an alert patient (i.e. not under the influence of alcohol or drugs) without neck pain, bony tenderness, focal neurological defect or a painful distracting injury. 

Obtain lateral, AP and an open mouth peg view if a cervical spine injury 

is suspected. 

In the lateral view ABCS have to be examined as described below:

A Alignment and adequacy: 

Visualize from base of skull to the C7/T1 junction. In-line arm traction, during the cross table lateral or a swimmer’s views can be helpful in visualising C7/T1. Look for the normal smooth curve of the anterior vertebral, posterior vertebral and spino-laminar lines. In a child pseudo-subluxation of C2 on C3 can cause confusion. In these cases, examine the spinolaminar line from C1 to C3. If the bases of these spinous processes lie 2 mm from this line an injury should be suspected. Correlate with soft tissue findings.The distance between the anterior arch of C1 and the odontoid peg should be 3mm in an adult and 5mm in a child.

Lateral cervical radiography showing (A) anterior vertebral line, (P) posterior vertebral line and (SL) spinolaminar line. 

B Bone:

Assess for normal bony outline and density. An increase in density may indicate a compression fracture.

C Cartilage: 

The intervertebral spaces should be uniform. Widening of these or the interspinous distance may indicate an unstable dislocation. An increase in interspinous distance of 50% suggests ligamentous disruption. Muscular spasm can make interpretation difficult.

S Soft tissues: 

Retro-pharyngeal soft tissue swelling may be the only sign of a significant injury. Normal measurements are less than 7mm C2–C4 (half a vertebral body at this level) and less than 22m below C5 (a vertebral body width). Air within the soft tissues suggests rupture of esophagus or trachea/bronchus. Bulging of the pre-vertebral fat stripe is an early sign.