Ligamentous injury of the cervical spine--two radiological signs.

The integrity of the posterior ligamentous complex is important for the stability of the cervical spine. Severe ligamentous injury may occur without radiological evidence of vertebral fracture or dislocation. If overlooked, ligamentous damage may result in vertebral instability with subsequent dislocation and spinal cord injury. Two radiological signs, acute kyphotic angulation and divergence of the spinous processes, which are indirect evidence of ligamentous damage, are described.