TRAUMATIC ISOLATION OF THE CERVICAL ARTICULAR PILLAR - IMAGING OBSERVATIONS IN 21 PATIENTS

OBJECTIVE. Imaging studies of patients diagnosed with traumatic isolat ion of a cervical articular pillar were retrospectively reviewed to be tter understand the mechanism, clinical significance, and management r equirements of this injury. MATERIALS AND METHODS. Imaging studies obt ained before definitive treatment of 21 patients with traumatic isolat ion of a cervical articular pillar were reviewed to determine the leve l and mechanism of injury, fracture patterns, and associated fractures . Lateral cervical radiographs and axial and reformatted sagittal cerv ical CT images were obtained for all patients. Medical records were re viewed to ascertain the neurologic deficit, if any and clinical manage ment. RESULTS. Traumatic isolation of a cervical articular pillar was diagnosed at 24 levels in the 21 patients. The imaging studies indicat ed that the injury mechanisms producing isolation of the articular pil lar were hyperflexion-rotation in 17 patients (81%), hyperflexion-dist raction in three patients (14%), and hyperextension-rotation in one pa tient (5%). A fracture through the transverse foramen ipsilateral to t he isolated articular pillar was observed in 19 patients (90%). Contra lateral injuries at the level of the isolated articular pillar were pr esent in 14 patients (67%). Neurologic deficits were present in 13 pat ients (62%) and included spinal cord injury (10) and radiculopathy (3) . Eighteen patients underwent surgical reduction and internal stabiliz ation. CONCLUSION. On the basis of an analysis of cervical radiography and CT findings, cervical spine fractures resulting in isolation of a n articular pillar most commonly occur from hyperflexion-rotation or h yperflexion-distraction mechanisms. Previous literature has indicated that cervical hyperextension is responsible for this injury, but hyper extension accounted for only one case in this series. It is important to identify the isolated cervical articular pillar as a component of o ther cervical fracture patterns, as the injury creates two levels of m echanical instability requiring internal fixation of three contiguous vertebrae.