Unilateral locked facet in cervical spine injuries.

Among 525 patients who sustained trauma to the cervical spinal cord, 86 (16%) had unilateral locking of facets. If the diagnosis is not promptly made, neurological recovery of root deficit will be impaired and orthopedic deformity will result. Since there is often only minimal forward displacement at the site of dislocation, it is possible not only to miss the locking of facets but even to erroneously conclude that no fracture or dislocation is present. Rotation of the cervical spine above the level of dislocation results in a diagnostic appearance on the lateral view. Rotation of the spinous processes was seen in the anteroposterior view in only one-third of the cases. The necessity of obtaining x-rays which adequately demonstrate the lower cervical spine is emphasized and the technique briefly described.