CT scan patterns of articular mass injuries of the lower cervical spine

Traumatic lesions of the cervical articular mass are infrequent, are potentially unstable and often require internal fixation. Standard X-rays and CT images can be difficult to analyze in an emergency situation. Standard X-rays must always be performed first, but CT, particularly helical CT, is the definitive imaging modality. Two-dimensional reformations are performed in all cases, together with 3-D reformations when indicated. We here present a simple and logical analysis based on the normal pattern of the interfacetal joint, which is always made of two pieces of bone, and only two, in a precise order. Post-traumatic deviations from this normal pattern reflect an injury, and there exists an accurate correlation between the CT pattern and the pathologic features.