Cervical spondylolysis, radiologic pointers of stability and acute traumatic as opposed to chronic spondylolysis.

STUDY DESIGN: Case report and literature review.

OBJECTIVES AND METHODS: We report a case of subaxial cervical spondylolysis and review 142 reports of this anomaly in the English language literature to determine the cause, the distribution, the stability, and the prognosis of cervical spondylolysis.

RESULTS: Cervical spondylolysis may affect any level of the lower cervical spine with the C6 isthmus being the most commonly affected region (48%). In 40% of cases, there were radiologic features consistent with congenital cervical spondylolysis and in 74% of cases there was a history of acute trauma. The radiographic features of congenital cervical spondylolysis are quite specific and can exclude trauma as a cause for the spondylolysis. Although instability was not commonly assessed, 30% of cases assessed with flexion-extension views were found to be unstable. These included 27 cases of myelopathy of which 26 were attributable to instability. Many treatment modalities have been employed to treat ranging from early mobilization to decompression and fusion. Three patients with radiologic signs of instability and no neurologic deficit were treated conservatively, whereas 1 patient with no neurologic deficit or instability was treated with spinal fusion.

CONCLUSIONS: We found a direct relationship between spinal instability and the presence of neurologic deficit (P < 0.001). On the basis of this systematic review of case reports of lower cervical spondylolysis, we can recommend that spondylolysis of the lower cervical spine can be treated nonoperatively except in those with radiologically documented cervical instability.