Anterior subluxation of the cervical spine

Anterior subluxation of the cervical spine, also known as hyperflexion sprain, is a ligamentous injury of the cervical spine.

Clinical presentation

Patients present with severe, focal neck pain. There may be neurological symptoms due to spinal cord injury.

Pathology

Anterior subluxation of the cervical spine results from posterior ligamentous complex injury, however, there may be an associated posterior intervertebral disc injury and compression fractures of the anterior vertebral bodies ^1-3. 

Causes include motor vehicle collisions (most common), diving into shallow water, falls and direct trauma ³. 

Radiographic features

Plain radiograph / CT

• may be normal
• focal kyphosis at the site of ligament disruption
  • helps to differentiate the condition from diffuse reversal of cervical lordosis
• increased interspinous distance
• concerned disc space shows reduced height anteriorly and increased height posteriorly
• mild anterolisthesis may be noted

MRI

MRI can demonstrate disruption of ligaments, including posterior longitudinal ligament, ligamentum flavum and interspinous ligaments:

• soft tissue edema is usually present: commonly in the interspinous space
• spinal cord edema may be seen: usually results from traumatic disc herniation rather than compression by bone