ABSTRACT

Sacral anatomy is unique when compared to the other vertebral columns. The posterior structure of the sacrum is similar to the upper part of the spinal column but the fusion between these segments.

On the other hand, anterior anatomy of the sacrum contains a bony bridge between the transverse processes and the vertebral body. This bony bridge contains tunnels. Anterior foramen of the S1 and S2 nerve root leaves the spinal canal in this bony tunnel and reaches to abdominal cavity. In this study we define the coronal angle of these two S1 and S2 tunnels on CT scans of 76 patients.