Sciatica 2020

Stimulated by Jeong et al,[1] and Huang et al.[2]

I am highlighting 2 papers. The first listed above is most recent and raises some interesting points, but the second paper, which is from last year, is more important from my perspective. I reviewed the latter for the journal Pain Medicine, and then when it was published, I found that I could not access the full text. I wanted to highlight it on this blog at the time but was not able to access it until much later. So, in short, I am using this first paper from last week as an excuse to return to one I missed.

Acupotomy

Have you heard of acupotomy?

Well, it is a rather surgical form of acupuncture that uses needles shaped like small chisels. The needles used in this study were 0.75mm in diameter and 80mm in length, and they were inserted after skin anaesthesia with Emla cream.

For comparison, a 21G green hypodermic needle, typically used to take a blood sample, is just over 0.8mm in diameter.

The insertion sites were described as 20-30mm away from the spinous process (SP) – presumably this was lateral to the SP. The needles were inserted 50-60mm, manipulated and immediately removed. The levels targeted were based on symptoms and the level of a herniated disc seen on MRI. At first, I thought the intention was to somehow directly target the extruded disc material, but thankfully I do not think that was the case. If the needles were inserted in a paramedian sagittal plane, 20-30mm lateral to the SP should be comfortably wide of the central canal. 50-60mm depth would reach the level of the facet joint or lamina, or fractionally beyond, but probably not deep enough to reach a nerve root.

So, in summary this is quite a strong manual stimulus to tissue, relatively close to the lumbar disc herniation (LDH). I should clarify that LDH was the main inclusion criteria, and not all patients had sciatica.

The treatment was applied 4 times over two weeks, and the comparison was with the same treatment schedule of relatively standard acupuncture. Fifteen points were used, with 9 in the lumbar region (4 bilateral points BL23-26, one central GV3), 4 in the legs (2 bilateral points BL40 & 60) and 2 in the head (GB3 bilateral). Needles were 0.25x40mm and were retained for 15 minutes. There is no mention of stimulating the needles or achieving any sensation, so this could have been a relatively mild intervention despite the number of needles, and of course it only involved 4 sessions.

The trial was moderately large (n=146), and I was expecting to see a larger dropout rate in the acupotomy group, but no, only 3 were lost from each group. Four sessions of acupotomy proved to be superior at 2, 4 and 6 weeks from baseline in terms of pain and functional outcome scales (RMDQ[3] & MMST[4]), but not in terms of health-related quality of life (EQ-5D).

…and the tissue plane favourable between intertransversarius and psoas

In terms of pain relief, the effect of the acupotomy was about twice as large, with a drop of VAS pain of 20 compared with a drop of just over 10 in the acupuncture group. I guess it is plausible that the tissue disruption caused by the acupotomy may have produced enough purines to diffuse close to the nerve root affected by the LDH – I estimate the distance may have been as little as 2cm, and the tissue plane favourable (between intertransversarius and psoas).

Moving on to a small study on chronic sciatica (n=46) from China. It was well reported and published in a well-known American pain journal for clinicians.[2]

This time there were 12 sessions over 4 weeks, with 0.35mm needles inserted into 4 points bilaterally (BL23, 25, 40 & 60) and manually stimulated 3 times over 30 minutes. The needles at BL25 were inserted 40-70mm, and at the other points the needles were inserted 30mm.

The control group received non-penetrating sham at the same points with no manipulation.

The short-term results demonstrated an improvement of real acupuncture over sham, but only at the end of treatment. But when we look at the change from baseline in VAS scores, and compare between these two trials, we see that the non-penetrating sham group in this small trial on chronic sciatica seems to have done better than the acupuncture group in the acupotomy trial. Indeed, this non-penetrating sham was associated with reductions in pain VAS of the same magnitude as the acupotomy in the other trial.

This led me to look more carefully at the populations recruited. Both had LDH, but only the trial on chronic sciatica insisted on at least 12 weeks history of sciatica. Baseline VAS pain was comparable at around 60.

Of course, the length of treatment was also quite different, with 4 sessions over 2 weeks and 12 sessions over 4 weeks. The one thing that seems to be important in treating chronic pain with acupuncture (from the Vickers IPDM) is the number of sessions.[5]

Sometimes you see these strange things…

Sometimes you see these strange things when you compare the results in different trials, so the best thing to do (from a strict EBM perspective) is avoid such comparisons, no matter how informal!

References

1         Jeong JK, Kim E, Yoon KS, et al. Acupotomy versus Manual Acupuncture for the Treatment of Back and/or Leg Pain in Patients with Lumbar Disc Herniation: A Multicenter, Randomized, Controlled, Assessor-Blinded Clinical Trial. J Pain Res 2020;13:677–87. doi:10.2147/JPR.S234761

2         Huang Z, Liu S, Zhou J, et al. Efficacy and Safety of Acupuncture for Chronic Discogenic Sciatica, a Randomized Controlled Sham Acupuncture Trial. Pain Med 2019;20:2303–10. doi:10.1093/pm/pnz167

3         Roland M, Morris R. A Study of the Natural History of Back Pain. Spine (Phila Pa 1976) 1983;8:141–4. doi:10.1097/00007632-198303000-00004

4         Tousignant M, Poulin L, Marchand S, et al. The Modified – Modified Schober Test for range of motion assessment of lumbar flexion in patients with low back pain: A study of criterion validity, intra- and inter-rater reliability and minimum metrically detectable change. Disabil Rehabil 2005;27:553–9. doi:10.1080/09638280400018411

5         Vickers AJ, Vertosick EA, Lewith G, et al. Acupuncture for Chronic Pain: Update of an Individual Patient Data Meta-Analysis. J Pain 2018;19:455–74. doi:10.1016/j.jpain.2017.11.005

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Declaration of interests MC