骨骼系统放射学基础（9）——C1横韧带不稳

Figure 9 Instability of the transverse ligament of C1. In this patient with rheumatoid arthritis, a lateral view of the cervical spine with the neck extended (A) shows very little space (which is normal) between the posterior aspect of the arch of C1 and the anterior portion of the odontoid (arrows). With flexion (B), this space markedly widens, and the odontoid is free to compress the spinal cord, which is posterior to it.