Malalignment: signs and significance

Malalignment of the vertebrae, in patients suspected of blunt spinal trauma, is the quintessential sign of spinal injury. Malalignment is obvious in displaced fractures and dislocations but is rarely considered in the diagnosis because of the obvious injury. In patients with more subtle injuries such as those limited to ligamentous structures, vertebral malalignment is the only radiographic sign that leads one to the recognition of the injury. Equally important is the fact that vertebral malalignment may be congenital and may be due to physiologic movement as well as radiographic patient positioning. Recognition of the pattern of traumatic malalignment as distinguished from the appearance of non-traumatic malalignment is essential to accurate radiologic diagnosis. Because malalignment is critical to the radiographic assessment of blunt cervical spine injury, this presentation is limited to the cervical spine. The format of the article includes signs of physiologic and traumatic malaignment as seen on antero-posterior and lateral radiographs of the cervico-cranium and the lower cervical spine.