Radiofrequency denervation not effective in chronic low back pain

1. This series of multi-center, non-blinded randomized control trials found that there was either no improvement or no clinically important improvement in chronic low back pain for patients treated with radiofrequency denervation, compared with a standardized exercise program.

2. No adverse reactions to radiofrequency ablation were reported, with the exception of a vasovagal reaction in the sacroiliac joint trial and a hematoma in the combination trial, of which the patients fully recovered.

Evidence Rating Level: 1 (Excellent)

Study Rundown: Low back pain (LBP) causes more disability among adults in the US than any other medical condition. LBP is associated with significant health care spending—estimated at 3.9 billion USD in 2007—as well as major social consequences for patients. Potential anatomical sources of LBP include facet joints, sacroiliac joints, and intervertebral discs. Radiofrequency denervation is commonly used as a treatment in pain clinics for chronic low back pain. However, despite a consensus among anesthesiologists that such procedures are effective for patients with mechanical LBP, the effectiveness of this technique has not been consistently demonstrated through clinical evidence. This study reports that randomized, unblinded clinical trials showed no significance in pain intensity after 3 months in patients treated with radiofrequency ablation compared to those treated with exercise alone.

This series of randomized clinical trials included large sample sizes and randomization that produced well-allocated study groups, and used appropriate outcome measures for low back pain research. In addition, the study was well followed, with a primary time point of 3 months and a secondary follow up of 12 months. However the study had some limitations. Firstly, there were various types of radiofrequency techniques used, but the groups were too small in number for subgroup analysis. Secondly, the study was not blinded, which is a significant limitation to the study. Thirdly, there is no reference standard available for diagnosing facet or sacroiliac joint pain, and the ideal threshold value of pain reduction was up for interpretation. Finally, it is unclear whether these results are generalizable due to the fact that there was a large portion of patients who had LBP were excluded because they simultaneously also had psychological problems – these patients were instead referred for psychological treatment, to abide by daily practice. Nonetheless, this study provides interesting findings that do not support the use of radiofrequency denervation to treat chronic low back pain.

Click to read the study, published in JAMA

Relevant Reading: Sacroiliac joint radiofrequency ablation with a multilesion probe: a case series of 60 patients.

In-Depth [randomized control study]: This multi-centered, unblinded, randomized control study took place across 16 multidisciplinary pain clinics in the Netherlands. Patients between 18 and 70 years of age who had pain related to their facet joints, the sacroiliac joints, or the intervertebral discs, were included in the study if they did not experience improvement in symptoms after conservative treatment. Primary outcome was pain intensity, measured in an 11-point numerical rating scale (NRS, 0-10, with 10 indicating worst pain imaginable) 3 months after intervention. Secondary outcomes included globally perceived recovery and patient satisfaction, as measured by the Global Perceived Effect scale (1-7, 1=very satisfied, 7=very unsatisfied). This study found no clinically significant difference in pain intensity after 3 months in patients treated with radiofrequency ablation compared to those treated with exercise alone.

A total of 681 patients were enrolled into the study and randomized into either a radiofrequency denervation plus exercise arm or an exercise alone arm. The 3 trials reported are the Facet Joint Trial, the Sacroiliac Joint Trial, and the Combination trial (a mix of facet, sacroiliac joint, and/or intervertebral disc pain). The intent to treat analyses showed the following: in the Facet Joint trial, mean difference for primary outcome pain intensity at 3 months was -0.18 (95% CI, -0.76 to 0.40), and the mean difference for functional status at 3 months was -2.45 (95% CI, -5.53 to 1.03). In the Sacroiliac Joint Trial, the mean difference for pain intensity at 3 months was -0.71 (95% CI, -1.35 to -0.06), and mean difference for functional status at 3 months was -4.20 (95% CI, -8.39 to -0.002). In the Combination Trial, the mean difference for pain intensity at 3 months was -0.99 (95% CI, -1.73 to -0.25), and mean difference for functional status at 3 months was -4.66 (95% CI, 0.99 to 3.36).

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