Bipolar Radiofrequency Facet Ablation of the Lumbar Facet Capsule: An Adjunct to Conventional Radiofrequency Ablation for Pain Management

Abstract

Radiofrequency facet ablation (RFA) has been performed using the same technique for over 50 years. Except for variations in electrode size, tip shape, and change in radiofrequency (RF) stimulation parameters, using standard, pulsed, and cooled RF wavelengths, the target points have remained absolutely unchanged from the original work describing RFA for lumbar pain control. Degenerative changes in the facet joint and capsule are the primary location for the majority of lumbar segmental pathology and pain. Multiple studies show that the degenerated facet joint is richly innervated as a result of the inflammatory overgrowth of the synovium. The primary provocative clinical test to justify an RFA is to perform an injection with local anesthetic into the facet joint and the posterior capsule and confirm pain relief. However, after a positive response, the radiofrequency lesion is made not to the facet joint but to the more proximal fine nerve branches that innervate the joint. The accepted target points for the recurrent sensory branch ignore the characteristic rich innervation of the pathologic lumbar facet capsule and assume that lesioning of these recurrent branches is sufficient to denervate the painful pathologic facet joint. This report describes the additional targets and technical steps for further coagulation points along the posterior capsule of the lumbar facet joint and the physiologic studies of the advantage of the bipolar radiofrequency current in this location. Bipolar RF to the facet capsule is a simple, extra step that easily creates a large thermo-coagulated lesion in this capsule region of the pathologic facet joint. Early studies demonstrate bipolar RF to the facet capsule can provide long-term pain relief when used alone for specific localized facet joint pain, to coagulate lumbar facet cysts to prevent recurrence, and to get more extensive pain control by combining it with traditional lumbar RFA, especially when RFA is repeated.

Direct Posterior Bipolar Cervical Facet Radiofrequency Rhizotomy: A Simpler and Safer Approach to Denervate the Facet Capsule

“…Since the initial description of the RF target in the cervical spine, the basic technique and the target for the radiofrequency lesion have not changed [ 1 - 2 ]. There has been some improvement in electrode design, the type of current used to create the radiofrequency lesion, such as pulsed RF and cooled RF current, adding bipolar electrodes to make larger lesions along the facet capsule, as well as modifications to different-shaped electrode tips, but there has not been a change in the target [ 6 - 7 ].…”

“…The shape and orientation remain unchanged regardless of the degree of segmental degenerative pathology. Biomechanically, the cervical facet joint provides mainly rotary and sagittal stability but minimal weight bearing [ 7 - 8 ]. This is markedly different from the lumbar facet joints that provide 20%-30% of the posterior column axial weight bearing in the normal spine but from 40%-60% of weight bearing with disc degeneration [ 7 ].…”

“…Biomechanically, the cervical facet joint provides mainly rotary and sagittal stability but minimal weight bearing [ 7 - 8 ]. This is markedly different from the lumbar facet joints that provide 20%-30% of the posterior column axial weight bearing in the normal spine but from 40%-60% of weight bearing with disc degeneration [ 7 ]. This shifting of spinal load on to the posteriorly located facet joints gradually leads to lumbar facet overgrowth and deformity.…”

“…This shifting of spinal load on to the posteriorly located facet joints gradually leads to lumbar facet overgrowth and deformity. In contrast, in the cervical spine, disc degeneration is accompanied primarily by the overgrowth of the anterior and lateral uncovertebral joint without significant deformity of the facet joint [ 7 , 10 ] (Figure 2 ).…”

“…To effectively "denervate" the facet capsule, not only one level above and below must be targeted, but it may be beneficial to add radiofrequency lesioning of the more horizontal posterior facet capsule [ 3 , 12 ]. As has been shown with pain from lumbar facet degeneration, targeting the facet capsule with its nerve-rich overgrown synovium may add additional benefits to the standard radiofrequency lesions [ 7 ].…”