Delayed post-traumatic cervical instability.
BACKGROUND: Cervical spine instability is a clinical entity whose biomechanical and radiological features have been widely discussed by many authors. On the other hand, the subject of delayed post-traumatic cervical instability is often surrounded by confusion due to its difficult nosologic framing; the aim of this study is to contribute to the matter. METHODS: A cooperative study was organized by the Study Group for Spinal Surgery of the Italian Society of Neurosurgery to evaluate cervical trauma patients surgically treated more than 20 days after the traumatic event. From a total number of 172 patients, twenty-five were admitted to the study, because neuroradiological investigations performed during the acute phase had shown either an absence of traumatic lesions or only minimal lesions judged to be stable. For this reason these 25 patients had not been treated by either surgery or immobilization in a halo vest. Some time after trauma, this group of patients clearly demonstrated evidence of unstable lesions requiring surgical treatment, following the appearance of new clinical signs or on neuroradiological follow-up. RESULTS: Re-examination of the neuroradiological investigations performed during the acute phase made it possible to identify elements that might have led us to suspect the presence of ligamental lesions: microfractures, dislocations less than 3 mm, and inversion of physiological lordosis. CONCLUSIONS: This review clearly indicates that patients with even mild cervical trauma must be scrupulously evaluated during the acute phase and that in some cases it is advisable to perform a more detailed neuroradiological investigation.