Lumbar zygapophysial (facet) joint radiofrequency denervation success as a function of pain relief during diagnostic medial branch blocks: a multicenter analysis

• Published in: The spine journal Vol. 8; no. 3; pp. 498 - 504
• Main Authors: Cohen, Steven P., Stojanovic, Milan P., Crooks, Matthew, Kim, Peter, Schmidt, Rolf K., Shields, Cynthia H., Croll, Scott, Hurley, Robert W.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.2008
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Anesthetics, Local - therapeutic use; Denervation; Denervation - methods; Facet joint; Female; Humans; Low back pain; Low Back Pain - drug therapy; Low Back Pain - radiotherapy; Lumbar Vertebrae; Male; Medical branch block; Middle Aged; Nerve Block; Orthopedics; Patient Selection; Predictive value; Radiofrequency; Zygapophyseal Joint - innervation; Zygapophyseal Joint - radiation effects; Zygapophysial joint; Facet joint; Low back pain; Predictive value; Zygapophysial joint; Radiofrequency; Medical branch block; Denervation
• ISSN: 1529-9430; 1878-1632
• DOI: 10.1016/j.spinee.2007.04.022

The publication of several recent studies showing minimal benefit for radiofrequency (RF) lumbar zygapophysial (l-z) joint denervation have led many investigators to reevaluate selection criteria. One controversial explanation for these findings is that the most commonly used cutoff value for selecting patients for l-z (facet) joint RF denervation, greater than 50% pain relief after diagnostic blocks, is too low and hence responsible for the high failure rate. To compare l-z joint RF denervation success rates between the conventional greater than or equal to 50% pain relief threshold and the more stringently proposed greater than or equal to 80% cutoff for diagnostic medial branch blocks (MBB). Multicenter, retrospective clinical data analysis. Two hundred and sixty-two patients with chronic low back pain who underwent l-z RF denervation at three pain clinics. Outcome measures were greater than 50% pain relief based on visual analog scale or numerical pain rating score after RF denervation persisting at least 6 months postprocedure, and global perceived effect (GPE), which considered pain relief, satisfaction and functional improvement. Data were garnered at three centers on 262 patients who underwent l-z RF denervation after obtaining greater than or equal to 50% pain relief after diagnostic MBB. Subjects were separated into those who received partial (greater than or equal to 50% but less than 80%) and near-complete (greater than or equal to 80%) pain relief from the MBB. Outcomes between groups were compared with multivariate analysis after controlling for 14 demographic and clinical variables. One hundred and forty-five patients obtained greater than or equal to 50% but less than 80% pain relief after diagnostic MBB, and 117 patients obtained greater than or equal to 80% relief. In the greater than or equal to 50% group, success rates were 52% and 67% based on pain relief and GPE, respectively. Among patients who experienced greater than 80% relief from diagnostic blocks, 56% obtained greater than or equal to 50% relief from RF denervation and 66% had a positive GPE. Using more stringent pain relief criteria when selecting patients for l-z joint RF denervation is unlikely to improve success rates, and may lead to misdiagnosis and withholding a potentially valuable treatment from good candidates.