Cervical flexion injury
Several cervical flexion injuries can result in cervical locked facets.
Hyperflexion sprain
A long-term follow-up study of a series of 45 consecutive patients with a hyperflexion sprain causing anterior subluxation of the cervical spine shows that conservative management is successful in more than 50 per cent of children and adults. In patients under 16 years of age, usually with involvement of the C2-C4 level, kyphosis may persist for months, but later realignment is common. Primary surgical treatment should be restricted to children with a kyphotic angulation of more than 20 degrees. In adults with injuries commonly at the C4-C7 level, the failure rate of conservative management indicates that primary surgical treatment should be preferred unless kyphotic angulation is less than 10 degrees. Kyphosis may progress during conservative management and may even result in unilateral interlocking. However, none of the patients with a persisting kyphotic angulation had neck complaints. Neurologic involvement when present was mild and reversible. Posterior wiring and fusion may entail inadvertent inclusion of adjacent segments without, however, causing major residual symptoms 1).