Interventional spine procedures for management of chronic low back pain-a primer

Abstract

Chronic low back pain is a common clinical condition. Percutaneous fluoroscopic-guided interventions are safe and effective procedures for the management of chronic low back pain, which can be performed in an outpatient setting. Interventional radiologists already possess the technical skills necessary to perform these interventions effectively so that they may be incorporated into a busy outpatient practice. This article provides a basic approach to the evaluation of patients with low back pain, as well as a review of techniques used to perform the most common interventions using fluoroscopic guidance.

Keywords: back pain injections; epidural steroid injection; facet block; interventional radiology; medial branch block; spine intervention.

Figure 1

Clinical algorithm for the management of chronic low back pain.

Figure 2

Interlaminar epidural steroid injection. Anteroposterior (A) and lateral (B) images of the lumbar spine showing focal distribution of contrast within the epidural space (arrow), confirming appropriate position of the needle tip prior to therapeutic injection.

Figure 3

Transforaminal epidural steroid injection. (A) Oblique view of the lumbar spine used to identify the target right L5 foramen. (B) The curved needle is advanced en-face to target the superior aspect of the foramen, beneath the pedicle. (C) Lateral view of the lumbar spine showing appropriate placement of the needle tip within the midportion of the right L5 foramen. (D) Anteroposterior image showing focal distribution of contrast around the right L5 nerve root, tracking centrally through the foramen around the thecal sac. Real-time fluoroscopy is performed during injection to exclude intravasation of the radicular artery.

Figure 4

Innervation of the zygapophysial (facet) joints. The medial branch of each spinal nerve gives rise to afferent nerve fibers that innervate both the facet joint capsule at that level and at the level immediately below it.

Figure 5

Targeting the medial branch of the spinal nerve. Oblique view of the lumbar spine showing appropriate needle tip position to target the medial branch of the right L3 spinal nerve. Fluoroscopic target is the junction of the transverse process and superior articular process of the facet joint (i.e., the junction between the “ear” and the “nose” of the “scotty dog”).

Figure 6

Medial branch block. Anteroposterior (A) and lateral (B) views showing appropriate needle tip position to target the medial branch of the right L4 spinal nerve (superior) and dorsal ramus of the right L5 spinal nerve (inferior) for sensory blockade of the right L5/S1 facet joint. Contrast disperses along the bone cortex without vascular intravasation.

Figure 7

Radiofrequency rhizotomy. Anteroposterior (A) and lateral (B) views showing appropriate positioning of the RF electrode to target the medial branch of the left L4 spinal nerve. The electrode tip should not extend beyond the superior margin of the transverse process, so as to avoid thermal injury to the ventral (motor) ramus of the adjacent spinal nerve.

Figure 8

Sacroiliac joint injection. Anteroposterior view showing needle access to the inferior joint space and appropriate distribution of contrast within the joint.