This trial found that destroying nerves that take pain signals to the brain using heat (radiofrequency denervation) did not improve pain, function or a sense of “recovery”. The treatment was used alongside exercise and was a variation of the technique commonly used in the UK. In this large study, it was compared to exercise alone.
Low back pain is usually short-lived, but some people develop long-term back pain which can negatively impact their lives. NICE recommends exercise, pain relief and self-management to cope with pain. If these treatments are not effective and pain is severe, then more intensive options, such as radiofrequency denervation can be considered.
These findings suggest that this technique of radiofrequency denervation does not provide a significant advantage in addition to exercise. This trial used different denervation techniques that are used in the UK, and the participants were still improving with exercise therapy. Radiofrequency denervation is only used in the UK when exercise is no longer effective. Therefore, the findings may not be directly applicable to practice in this country, but certainly, raise doubt regarding its use.
Why was this study needed?
Low back pain of no specific source is the single biggest cause of disability worldwide. Exact UK figures are lacking as it is recorded alongside other musculoskeletal conditions. However, an estimated 30.6 million working days were lost in 2013 due to these conditions.
In most cases, back pain resolves quickly. However, chronic back pain can interfere with everyday life, lead to time off work or education and affect the quality of life. Chronic back pain can be difficult to treat if it does not respond to initial measures such as exercise and pain relief medication.
Radiofrequency denervation is used to treat chronic back pain where initial treatment has not worked. Needles are inserted next to nerve endings. Radiowaves heat the tip of the needle, which causes changes in the structure and function of the nerve.
This randomised controlled trial aimed to assess the effectiveness of radiofrequency denervation.
What did this study do?
The multi-centre MINT trial included 681 adults aged 18 to 70 from the Netherlands with chronic low back pain. They were randomly allocated to receive radiofrequency denervation in addition to a personalised exercise plan or just the exercise plan as a control group.
Results were analysed according to the location of back pain: facet joint pain (small stabilising joints between vertebrae), sacroiliac joint pain (the joint between the bottom of the spine and the pelvis) and a combination of pain sources.
The main limitations were that 25-35% of control participants also received the radiofrequency denervation intervention after three months. The participants were also aware of which treatment they had received, which could have biased their self-reported symptoms.
What did it find?
- Both groups improved similarly. There was no significant difference in pain intensity (measured on an 11-point scale) at 12 months after treatment for control participants having exercise alone or for those receiving radiofrequency denervation as well. Pain intensity scores reduced in all groups from around seven at the beginning of the study to between four and five at 12 months.
- The overall mean difference in pain intensity score between the intervention and control group was ‑0.08 (95% confidence interval [CI] ‑0.50 to 0.34) for facet joint participants, ‑0.40 (95% CI ‑0.83 to 0.03) for sacroiliac joint participants and ‑0.21 (95% CI ‑0.76 to 0.35) for combination participants.
- There was no difference in function on a 1-100 scale for facet joint participants (between-group mean difference 0.04, 95% CI ‑3.02 to 3.10), sacroiliac joint participants (0.42, 95% CI ‑2.99 to 3.82) or combination participants (1.90, 95% CI ‑2.96 to 6.76).
- There was also no difference in participants’ perception of their recovery or the reduction in pain intensity.
What does current guidance say on this issue?
NICE 2016 guidelines recommend conservative management of low back pain involving self-management of pain, group exercise programmes, manual therapy (such as spinal manipulation or massage) and psychological therapy to help cope with pain. Non-steroidal anti-inflammatory drugs can be used at the lowest effective dose and for the shortest possible period. Weak opioids are only recommended when these simpler treatments have been ineffective or cannot be used.
Radiofrequency denervation is recommended when conservative treatments have not worked, the source of pain is thought to be nerve-based, or the pain is moderate to severe. NICE recommends radiofrequency denervation only in people who have had a positive response to an anaesthetic procedure called a diagnostic medial nerve branch block.
Details of the technique recommended in the UK are published in joint guidance from the British Pain Society and the Faculty of Pain Medicine of the Royal College of Anaesthetists.
What are the implications?
This trial suggests that this technique of radiofrequency denervation combined with exercise does not lead to better outcomes than exercise alone for chronic low back pain.
The radiofrequency denervation techniques used in this trial differed from those used in the UK, where a bigger needle is used at a slightly different angle. It is also only recommended for people who have not responded to exercise – whereas the people in the trial were still benefiting from exercise.
These are important points to note as there are few other available treatment options when physical treatments fail. The UK style of treatment and target population group may be sufficiently different that it could still be beneficial, but pending further research caution in the use of radiofrequency denervation seems advisable.
Citation and Funding
Juch JNS, Maas ET, Ostelo RWJG, et al. Effect of Radiofrequency Denervation on Pain Intensity Among Patients With Chronic Low Back Pain: The Mint Randomized Clinical Trials. JAMA. 2017;318(1):68-81.
This study was funded by grant 171202013 from the Netherlands Organization for Health Research and Development, by the Dutch Society for Anesthesiology, and the Dutch health insurance companies.
British Pain Society. Standards of good practice for medial branch block injections and radiofrequency denervation for low back pain. London: British Pain Society; 2014.
Hoy D, March L, Brooks P, et al. The global burden of low back pain: estimates from the Global Burden of Disease 2010 study. Ann Rheum Dis. 2014;73(6):968-74.
NHS Choices. Back pain. London: Department of Health; 2017.
NICE. Low back pain and sciatica in over 16s: assessment and management. NG59. London: National Institute for Health and Care Excellence; 2016.
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