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Radiofrequency denervation for lumbar zygapophysial joint pain.

Three Part Question

[In patients with chronic low back pain of zygapophysial joint origin] is [radiofrequency denervation of medial lumbar nerves better than standard rehabilitation] at [improving pain and function]

Clinical Scenario

A 55 year old woman represents to her general practitioner with back pain of 3 years duration. Previous assessments and investigations have not suggested a serious cause of her back pain but it so severe that she has had to give up work and has become depressed. She attends as she has read on the internet that the nerves to the joints in the back can be electrified and that this will cure her pain. She asks you if this is true and if so could you refer her for the treatment.

Search Strategy

Medline 1966 - June 2005. OVID via ATHENS.
[low back pain.mp. or exp Low Back Pain/ or back pain.mp. or exp Back Pain/ or lumbar pain.mp.] and [zygapophysial.mp. or exp Zygapophyseal Joint/ or facet joint.mp.] and [radio$.mp. or radiofrequency.mp. or exp DENERVATION/ or denervation.mp.] limit to humans and english language and abstracts.

Search Outcome

Medline.
86 papers found of which one 2 recent high quality sytstematic reviews were found. In addition a recent clinical trial was identified.

Relevant Paper(s)

Author, date and country Patient group Study type (level of evidence) Outcomes Key results Study Weaknesses
Niemisto l
2003
Finland
Randomised controlled trials of radiofrequency denervation for neck and back pain. Identified through wide ranging search under the auspices of the Cochrane Collaboration.Systematic review.Number of papers found7 RCTs were identified. 6 were high quality. 3 papers (including a total of 142 patients) specifically looked at lumbar zygapophysial pain.Lack of consistent outcome measure in the included trials. Lack of placebo controlled diagnostic blocks may have led to an increased number of false positive included patients.
Inclusion criteria in trials.All were in chronic back pain. All patients in the lumbar trials had confirmatory diagnostic blocks before being considered for denervation.
Principle resultsOne study showed a small decrease in short term pain (van Kleef), one showed a neutral effect and one was flawed due to a lack of intention to treat. There was conflicting evidence with regard to function scores. No formal meta-analysis was performed.
Slipman CW
2003
USA
Clinical trials of zygapophysial joint injections for patients with chronic back painSystematic review (without meta-analysis)Number of papers found15 studies were found, 4 were prospective trials included in this review. 2 were RCTs, one was a double blind controlled study and one was a case series.Confirmatory blocks were usually single attempts and may have led to an increase in the number of false positive included patients.
Patient characteristicsTrials included patients unresponsive to other therapies which means that there is a degree of inclusion bias. All patients had chronic back pain. All patients had a confirmatory diagnostic block prior to randomisation.
Principle outcome measuresPain: Conflicting results were found though there does appear to be a benefit in terms of short to medium term pain relief. Disability scores and improvements were less convinving and of questionable clinical significance
Mikeladze G
2003
USA
114 patients in a pain management clinic. Retrospective recruitment. All patients had had a positive response to a diagnostic medial nerve block.83/114 had low back pain.Observational retrospective cohortPain relief as measured on VAS.46/114 patients did not respond favourably (defined as less than 50% pain reduction). 68 patients had more than 50% pain relief.This is a low quality design and would have been excluded from the other review articles on the grounds of methodological weakness. No control group. Retrospective. Small numbers. Not possible to discriminate between lumbar and cervical patients as analysed together.

Comment(s)

Low back pain is one of the most common reasons for working age patients to suffer chronic pain, sickness and work loss. Studies have suggested that a significant proportion of patients with low back pain will have pain originating from the zygapophysial joints. A theoretically attractive theraputic intervention is to ablate the medial lumbar nerves that supply the joint, thereby rendering it anaesthetic. In all these studies the presence of zygapophysial pain was confirmed using diagnostic blocks which is an essential precurser to any trial in this area. The two reviews, whilst assessing the same papers come to similar conclusions that there is evidence for a degree of pain relief in the short to medium term but that there is little evidence to suggest that this is match ed by an increase in function. The most recent trial contains no control group and is retrospective and therefore of little help in answering the question.

Clinical Bottom Line

In patients with confirmed zygapophysial joint pain radiofrequency ablation of medial lumbar nerves may provide short to medium term pain relief but is unlikely to result in a significantly increased functional capacity.

Level of Evidence

Level 2 - Studies considered were neither 1 or 3.

References

  1. Niemesto L. Kalso E, Malmivaara A, Seitsalo S, Hurri H. Radiofrequency denervation for neck and back pain: A systematic review within the framework of the cochrane collaboration back review group. Spine 2003;28:1877-1888
  2. Slipman CW, Bhat AL, Gilchrist RV, Issac Z, Chou L, Lenrow DA. A critical review of the evidence for the use of zygapophysial injections and radiofrequency denervation in the treatment of low back pain. The Spine Journal 2003;3:310-316
  3. Mikeladze G, Espinal R, Finnegan R, Routon J, Martin D. Pulsed radiofrequency application in treatment of chronic zygapophyseal joint pain. The Spine Journal 2003;3:360-362