Radiofrequency denervation improved chronic low back pain arising from the facet joints to a greater extent than sham procedures or epidural blocks, especially in patients with the best response to diagnostic nerve block, according to a study published in The Spine Journal.1
Facet joint arthropathy, also known as lumbar zygapophysial joint arthropathy, accounts for up to 45% of patients with chronic low back pain. Intraarticular steroid injections and radiofrequency denervation are effective in treating related facet joint pain as they target the medial branches of the primary dorsal rami of the spinal nerves that innervate the facet joints.1,2
Radiofrequency denervation is typically used to treat facet joint pain after conventional therapies have failed, or to provide long-term pain relief. However, the data supporting these indications are inconsistent and suffer from methodologic issues, in that outcome assessment tools have not been validated and facet joints that are at the source of low back pain have not been identified.3,4
Researchers sought to examine the efficacy of radiofrequency denervation in chronic low back pain due to facet joint arthropathy by comparing this treatment with epidural steroid injections and sham procedures in a meta-analysis of the current evidence. The main outcome measure was a change in visual analog scale (VAS) of a minimum of 3 out of 10 points.
Of 454 patients from 7 trials, 231 were treated with radiofrequency denervation and 223 had undergone an epidural block or sham procedure (control group). Patients were categorized into subgroups based on response to diagnostic nerve block, with best response defined as ≥80% improvement in low back pain.
Compared with the control group, patients treated with radiofrequency denervation had significantly greater improvement in VAS scores at 6 months (mean difference [MD], 1.52) and 12 months (MD, 3.55). Changes from baseline VAS score in favor of reduced back pain in the radiofrequency group were 3.38, 3.33, and 5.65 at 1 to 3 months, 6 months, and 12 months.
Significant improvements in VAS score were observed at all time points in patients who were the best responders to diagnostic nerve block. These results were a significant driver for the improvements observed in the pooled study population.
Summary and Clinical Applicability
Radiofrequency denervation is commonly used to treat chronic low back pain associated with facet arthropathy, although the data supporting its use for this indication are inconsistent. In this meta-analysis, researchers found that radiofrequency denervation reduced low back pain to a greater degree than epidural injections or sham procedures in this population.
“In the present meta-analysis, we observed substantial decreases in back pain that exceeded the [minimal clinically important difference], and that these decreases in VAS score were maintained throughout the 12-month follow-up. Our findings, which include data obtained for the 1-year follow-up, may help clinicians make a more informed decision when selecting between radiofrequency denervation and alternative treatments,” the investigators wrote.
- This study measured changes in low back pain using VAS, which is subjective and may introduce bias
- Some studies included in the meta-analysis used analgesic therapies and physiotherapy in conjunction with the study treatments
- Lee CH, Chung CK, Kim CH. The efficacy of conventional radiofrequency denervation in patients with chronic low back pain originating from the facet joints: a meta-analysis of randomized controlled trials. [published online May 30, 2017] Spine J. doi:10.1016/j.spinee.2017.05.006
- Cohen SP, Raja SN. Pathogenesis, diagnosis, and treatment of lumbar zygapophysial (facet) joint pain. Anesthesiology. 2007;106(3):591-614.
- Sae-Jung S, Jirarattanaphochai K. Outcomes of lumbar facet syndrome treated with oral diclofenac or methylprednisolone facet injection: a randomized trial. Int Orthop. 2016;40(6):1091-1098. doi:10.1007/s00264-016-3154-y
- van Wijk RM, Geurts JW, Groen GJ. Comments on efficacy of radiofrequency facet denervation procedures. Pain Med. 2012;13(6):843-845. doi:10.1111/j.1526-4637.2012.01389.x.