Normal C-spine X-rays do not exclude significant injury
Clinical considerations are of particular importance when assessing appearances of C-spine X-rays
Look at all views available in a systematic manner
C-spine - Systematic approach
Coverage - Adequate?
Alignment - Anterior/Posterior/Spinolaminar
Bones - Cortical outline/Vertebral body height
Spacing - Discs/Spinous processes
Soft tissues - Pre-vertebral
Edge of image
C-spine fractures
Cervical spine injuries often have characteristics which depend on the mechanism of injury. This page describes typical appearances of some common C-spine fractures.
C1 fracture
Injury to C1(atlas) results in loss of integrity of its ring structure. The ring expands and loses alignment with the adjacent occipital bone above, and C2 below. This is most readily appreciated on the open mouth view which shows that the lateral masses of C1 no longer align with the lateral masses of C2, and that the spaces between the peg and the C1 lateral masses are widened.
It is uncommon to see such an obvious fracture on the open mouth view - many fractures of the odontoid peg are more readily seen on the lateral view
C2 'hangman' fracture
The so called 'hangman' fracture results from a high force hyperextension injury. The fracture involves the pedicles of C2 and often results in anterior displacement of the body and peg of C2.
Loss of alignment at C2/C3 with anterior displacement of C2 (large arrow)
Following the cortical outline of C2 (white line) reveals discontinuity due to a fracture
'Extension teardrop' fracture - Lateral view
Hyperextension may result in avulsion of the anterior corner of a vertebral body - most commonly C2. The anterior longitudinal ligament remains attached to the bone fragment which is separated from the vertebral body.
Following the outline of the vertebral bodies shows an anterior - inferior C6 vertebral corner 'teardrop' fracture fragment
The facet joint of C6/C7 is widened - compare with level above
C-spine dislocation injury
It is possible to sustain severe C-spine or spinal cord injury without evidence of a fracture. Dislocations may be transient with spontaneous relocation of the joints at the time of injury. Occasionally there may be locking or 'perching' of the facet joints preventing the bones from returning to their normal positions. This may be unilateral or bilateral.
At the level of C3 the pre-vertebral soft tissue is thickened - ( >1/3rd the width of the vertebral body)
This soft tissue swelling is the only visible sign of injury
CT showed a fracture at C4 not visible on the plain X-ray
Note
Not all C-spine fractures are accompanied by pre-vertebral haematoma
Lack of pre-vertebral soft tissue thickening should NOT be taken as reassuring
Spinous process 'clay-shoveller's' fracture
Isolated fractures of the spinous processes are often difficult to identify, especially at the cervico-thoracic junction where they may be obscured by overlying soft tissues. A specific check is necessary of the cortical outline of each spinous process.
These avulsion injuries are traditionally known as 'clay-shoveller's' fractures due to the mechanism of repeated forceful flexion associated with shovelling.
