Thoracic zygapophysial (facet) joint injections are performed by entering the zygapophysial joint at the inferior aspect of the joint. A substantial caudad tilt of the fluoroscope is required to accomplish a trajectory view of the joint space because of the steep coronal orientation of the thoracic zygapophysial joints. Unfortunately, the torso prevents the fluoroscope from reaching the required degree of caudad tilt for a trajectory view.

The reliable approach described herein can be used to routinely allow for the placement of a spinal needle into the thoracic zygapophysial joint. This technique has been previously described in the literature using a posterior approach with anteroposterior (AP) visualization. With AP visualization, the needle tip can be maintained along the midpedicular line, which corresponds with the midline of the zygapophysial joints and prevents the straying of the needle medially or laterally to avoid the neural and pulmonary structures. Contralateral oblique imaging provides for the visualization of the posteroinferior joint space, thereby allowing for needle placement into the joint. Using a bent needle tip ( Chapter 2 ) is helpful for navigating into the joint and overcoming osseous obstacles in a degenerative joint.

The needle entry site into the skin is confirmed with AP visualization at the pedicle one vertebral segment below the designated zygapophysial joint. For example, the entry site in most individuals for a left T8-T9 zygapophysial joint injection is the 6 o’clock position of the left T10 pedicle, and the target site for entry into the Z-joint is the 12 o’clock position of the T9 pedicle ( Fig. 22A.1, B ). The rationale for the skin entry and Z-joint target sites is to approximate the “trajectory angle” of the needle tip into the posteroinferior aspect of the joint space because of its near coronal orientation and inability to obtain a trajectory view with fluoroscopy. The needle tip is advanced with fluoroscopy and makes contact with the lamina at the base of the superior articular process of the target Z-joint. The needle tip trajectory is then adjusted and advanced into the Z-joint in the contralateral oblique view.