Radiofrequency denervation for chronic axial back pain.

Radiofrequency denervation for chronic axial back pain.

                                   DR KS Dhillon 

What is radiofrequency denervation?

Radiofrequency denervation, radiofrequency neurotomy, and radiofrequency ablation are often used interchangeably. They all refer to a procedure that destroys the functionality of the nerve using radiofrequency energy.

There are primarily two types of radiofrequency ablation used in the treatment of axial back pain:

• A medial branch neurotomy which is used for treatment of spinal facet joint pain. 
• A lateral branch neurotomy which is used to treat pain from  the sacroiliac joints.

The facet joint is innervated by the medial branch of the dorsal rami from 2 adjacent spinal segments. The nerve supply of the SI joint is a contentious issue. The information is sparse and variable. For radiofrequency ablation (RFA) of the SI joint, the medial branch of L4, dorsal rami of L5, and lateral branches S1 and S2, are targeted.

The procedure involves setting up of an IV line, sedation, skin preparation, local anesthetic injection, fluoroscopic guided insertion of radiofrequency needle to the required site and passage of a small current to confirm the targeted nerve, numbing of the target nerve with local anesthetic, passage of radiofrequency waves to heat the tip of the needle and creating a heat lesion to denervate the nerve.

Efficacy of radiofrequency denervation for facet joint pain

Radiofrequency facet joint denervation procedures for the treatment of chronic low back pain have been in common use for more than 3 decades.  The efficacy of the procedure, however, has never been conclusively established.

van Wijk et al [1], in 2005, published the outcome of a multicenter, randomized, double-blind, sham treatment controlled trial to determine the efficacy of radiofrequency facet joint denervation. They had a total of 81 patients who were randomized to undergo radiofrequency facet joint denervation or sham treatment. A twice weekly recording of VAS, physical activity and analgesic intake determined the primary outcome. The secondary outcome measure included the global perceived effect (complete relief, >50% relief, no effect, pain increase), and the SF-36 Quality of Life Questionnaire.They carried out the first evaluation 3 months after treatment. There were no dropouts in the first evaluation. They found that the combined outcome measure showed no differences between radio- frequency facet joint denervation and the sham group.The VAS improved in both groups. Only the global perceived effect improved after radiofrequency facet joint denervation. They concluded that only in selected patients, radiofrequency facet joint denervation appears to be more effective than sham treatment but overall there is no benefits from radiofrequency denervation in treatment of chronic low back pain.

Gofeld et al [2] did a prospective clinical audit for quality in 209 patients with chronic back pain who were treated with radiofrequency denervation of the lumbar zygapophysial joints. The patients were screened and those with multiple unrelated painful sites, significant psychopathology and those with unrealistic goals were not included in the study. One hundred and seventy four patients (83%) completed the study. The patients were asked to complete a questionnaire at 6 weeks, 6 months and at 12, and 24 months following the procedure. They were asked to estimate the total perceived pain reduction on a scale of 0% to 100%. Improvement of pain more than 80% was graded as excellent and between 80% to 50% was graded as good. Pain improvement less than  50% and pain relief lasting less than 6 months were considered as treatment failure.

In 55 (31.6%) patients, the treatment was a failure. One hundred and nineteen (68.4%) patients had good to excellent pain relief at 6 months follow up. Of the 119 patients, 81 (96.4%) reported pain relief for 6–12 months, 36 (42.8%) for 12–24 months, and 2 (2.4%) for more than 24 months. The median pain relief among all eligible 174 patient was 9 month.

All the 119 patients with a positive response were able to increase their physical activities, and 99 (83.2%) of these also decreased their consumption of analgesics (not stopped use of analgesics) and in 20 other patients with a positive response the use of analgesics remained unchanged.
These figures do, however, raises doubts about the efficacy of the procedure which can be associated with complication, because the procedure did not eliminate the use of analgesics and only 2.4% of patients had relief after 24 months.

Lakemeier et al [3] carried out a randomized, controlled, double-blind trial, to compare intraarticular lumbar facet joint steroid injections and lumbar facet joint radiofrequency denervation in the treatment of low back pain. The Roland-Morris Questionnaire was the primary endpoint and the secondary endpoints were the visual analog scale and the Oswestry Disability Index. The outcome assessments were performed at baseline and at 6 months. The study involved fifty-six patients where 24 of 29 patients in the steroid injection group and 26 of 27 patients in the denervation group completed the 6-month follow-up. There was pain relief and functional improvement in both groups and there were no significant differences between the 2 groups for both the primary endpoint and secondary endpoints.

This study, if valid, would encourage the use of intraarticular lumbar facet joint steroid injections rather than joint radiofrequency denervation for treatment of lumbar facet pain, and in doing so, resources can be saved.

Maas et al [4] did Cochrane Database Systematic Review in 2015 to assess the effectiveness of RF denervation procedures for the treatment of patients with chronic low back pain.The authors found that there is no high-quality evidence which suggests that RF denervation provides pain relief for patients with chronic low back pain. They also found no convincing evidence to show that such treatment improves function. They concluded that the current evidence for RF denervation for chronic low back pain is very low to moderate in quality and high-quality evidence does not exist.

Juch et al [5] conducted three pragmatic multicenter, non blinded randomized clinical trials to assess the effectiveness of radiofrequency denervation in patients with chronic low back pain originating from the facet joints, sacroiliac (SI) joints and or the disc. They found that radiofrequency denervation combined with a standardized exercise program resulted in either no improvement or no clinically important improvement in chronic low back pain compared with a standardized exercise program alone. They concluded that their findings do not support the use of radiofrequency denervation to treat chronic low back pain from the facet and SI joints and the disc.

Lee et al [6] in 2017 carried out a meta-analysis of 7 RCT for a total of 454 patients with low back pain due to facet joint disease of the lumbar spine. Comparison was made between patients who had radiofrequency denervation and those who had control/sham treatments. The follow up was upto 1 year. Two hundred and thirty one patients had radiofrequency ablation and 223 patients had control treatments such as sham or epidural block procedures. At 1 year follow up, there was a greater improvement in the radiofrequency denervation group and the mean difference for VAS scores between the two groups was 3.55.The authors concluded that radiofrequency denervation produced significant reduction in low back pain originating from the facet joints compared with sham procedures or epidural nerve blocks.

The systematic reviews (SRs) indicate that there is conflicting evidence regarding the benefits of radiofrequency denervation for facet joint pain, which makes it difficult to recommend it for treatment of chronic low back pain. Most of the studies included in the  SRs were usually small with a mix of randomized and non-randomized studies. The studies did not document well the adverse events and complications related to the radiofrequency denervation procedure. The primary studies had small population size and were of short duration which makes it difficult to determine the long term benefits associated with the procedure.

Since there is no long term outcome data available to determine the benefits of the procedure, the literature does not support the use of the procedure to treat chronic low back pain.

References

1. van Wijk RM, Geurts JW, Wynne HJ, Hammink E, Buskens E, Lousberg R, Knape JT, Groen GJ. Radiofrequency denervation of lumbar facet joints in the treatment of chronic low back pain: a randomized, double-blind, sham lesion-controlled trial. Clin J Pain. 2005 Jul-Aug;21(4):335-44.
2. Gofeld M, Jitendra J, Faclier G. Radiofrequency denervation of the lumbar zygapophysial joints: 10-year prospective clinical audit. Pain Physician. 2007 Mar;10(2):291-300.
3. Lakemeier S, Lind M, Schultz W, Fuchs-Winkelmann S, Timmesfeld N, Foelsch C, Peterlein CD. A comparison of intraarticular lumbar facet joint steroid injections and lumbar facet joint radiofrequency denervation in the treatment of low back pain: a randomized, controlled, double-blind trial. Anesth Analg. 2013 Jul;117(1):228-35.
4. Maas ET, Ostelo RW, Niemisto L, Jousimaa J, Hurri H, Malmivaara A, van Tulder MW. Radiofrequency denervation for chronic low back pain. Cochrane Database Syst Rev. 2015 Oct 23;(10):CD008572.
5. Juch JNS, Maas ET, Ostelo RWJG, Groeneweg JG, Kallewaard JW, Koes BW, Verhagen AP, van Dongen JM, Huygen FJPM, van Tulder MW. Effect of Radiofrequency Denervation on Pain Intensity Among Patients With Chronic Low Back Pain: The Mint Randomized Clinical Trials. JAMA. 2017 Jul 4;318(1):68-81.
6. 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. Spine J. 2017 Nov;17(11):1770-1780.