Position and anatomical landmarks
The patient lies in the prone position on the operating table with a pillow under the pelvis in such a way that the sacral bone is rotated in a ventral direction. The patient is lightly sedated.
The C-arm is positioned in such a way that either a slightly oblique view (L4 dorsal branch), AP view (L5 dorsal branch and lateral branches), or cranial caudal view (S1 to S3 lateral branches) is obtained. For S1, slight ipsilateral oblique angulation can often increase visualisation of the posterior foramen. See figure 1 and 2 for position of the needle.
Figure 1. Intra-articular injection of the SI joint with contrast.
Figure 2. Intra-articular injection of the SI joint with contrast.
- Temporary paresis of the ischial nerve.
- Damage to the ischial nerve, lumbar and sacral nerve roots.
- Temporarily increasing pain.