Using acupuncture to treat knee pain–no evidence

hellraiser-acupunctureLet’s start right from the beginning–there is no evidence that acupuncture has any significant clinical benefit for any condition. And because there is a small, but significant, risk associated with the acupuncture, the risk to benefit ratio is huge (if not infinity, since there is no benefit). There is simply no reason to accept, even a small risk, if there is no benefit to a procedure.

Just in case you don’t accept my words about acupuncture, Steven Novella, MD, of the Science Based Medicine blog, clarifies why acupuncture does not work:

Clinical research can never prove that an intervention has an effect size of zero. Rather, clinical research assumes the null hypothesis, that the treatment does not work, and the burden of proof lies with demonstrating adequate evidence to reject the null hypothesis. So, when being technical, researchers will conclude that a negative study “fails to reject the null hypothesis.”

Further, negative studies do not demonstrate an effect size of zero, but rather that any possible effect is likely to be smaller than the power of existing research to detect. The greater the number and power of such studies, however, the closer this remaining possible effect size gets to zero. At some point the remaining possible effect becomes clinically insignificant.

In other words, clinical research may not be able to detect the difference between zero effect and a tiny effect, but at some point it becomes irrelevant.

This is basic scientific reasoning. We cannot prove that acupuncture does not work, but if the effect is so small, that it is clinically irrelevant, in effect, it is a zero effect. And the clinical effect being observed has to be beyond just small, tiny, and debatable changes, they need to be clear to any independent observer. Thus, as Dr. Novella continues in his article,

…after decades of research and more than 3000 trials, acupuncture researchers have failed to reject the null hypothesis, and any remaining possible specific effect from acupuncture is so tiny as to be clinically insignificant.

In layman’s terms, acupuncture does not work – for anything.

This has profound clinical, ethical, scientific, and practical implications. In my opinion humanity should not waste another penny, another moment, another patient – any further resources on this dead end. We should consider this a lesson learned, cut our losses, and move on.

I suspect, however, human nature being what it is, that this will not happen anytime soon.

David Colquhoun and Novella, in a systematic review of clinical research of acupuncture, reviewed much of what passes for “science” in the field. And they found no evidence supporting the clinical value of acupuncture:

Large multicenter clinical trials conducted in Germany (here, here, here and here) and the United States consistently revealed that verum (or true) acupuncture and sham acupuncture treatments are no different in decreasing pain levels across multiple chronic pain disorders: migraine, tension headache, low back pain, and osteoarthritis of the knee.

If, indeed, sham acupuncture is no different from real acupuncture, the apparent improvement that may be seen after acupuncture is merely a placebo effect. Furthermore, it shows that the idea of meridians is purely imaginary. All that remains to be discussed is whether or not the placebo effect is big enough to be useful, and whether it is ethical to prescribe placebos.

Given that there is no evidence that acupuncture has any clinical benefit, there seems to be a continued desire to waste research dollars to debunk acupuncture. Of course, it just gives us acupuncture skeptics (mean in the true meaning of skepticism, that accepting a claim is dependent upon the quality and quantity of evidence presented) things to write.


In a recent article in the Journal of the American Medical Association (JAMA), Hinman et al. examined the potential benefit of acupuncture for chronic knee pain. In this blinded and controlled clinical trial, the researchers placed 282 patients with chronic knee pain into four groups: control, sham acupuncture (a method that appears to be real acupuncture to the subjects and researchers), needle acupuncture, and laser acupuncture. All other variables were the same across the group, including weight, body mass index, use of medications (like glucosamine, which also doesn’t work), and other factors.

The primary outcomes of the study were targeted to be: average knee pain (a subjective measurement on a 0-10 scale from the subject), minimal clinically important difference, and physical function. Secondary outcomes included other types of pain and motion measurements, along with 1 year follow up.

Hinman et al. observed that:

  • There were no significant differences in primary outcomes between active and sham acupuncture at 12 weeks or 1 year.
  • Both needle and laser acupuncture resulted in modest improvements in pain compared with control at 12 weeks that were not maintained at 1 year.
  • Needle acupuncture improved physical function at 12 weeks compared with control but was not different from sham acupuncture and was not maintained at 1 year.
  • Most secondary outcomes showed no difference.
  • Needle acupuncture improved pain on walking at 12 weeks but was not maintained at 1 year and improved activity restriction at 1 year compared with control.
  • Complete case analyses gave similar results with no differences persisting for primary outcomes between active and sham acupuncture. When analyzed as treated, there were still no differences in primary outcomes between active and sham acupuncture.

The authors then concluded in a clear manner rarely seen in scientific research:

Among patients older than 50 years with moderate to severe chronic knee pain, neither laser nor needle acupuncture conferred benefit over sham for pain or function. Our findings do not support acupuncture for these patients.

These results are unsurprising. There is simply no plausible reason why acupuncture would work for pain, and study after study seems to support the null hypothesis–any specific effect from acupuncture is so small that it is considered clinical insignificant. Yes, some might claim that there’s some “placebo effect,” but many researchers, myself included, consider the placebo effect to be a myth, and that it still lacks clinical usefulness. Acupuncture relies upon pseudoscientific beliefs that there are certain locations on the body that, with acupuncture, can cause certain clinical benefits.

Colquhoun and Novella reviewed the data surrounding the myth of acupuncture and found that:

The best controlled studies show a clear pattern, with acupuncture the outcome does not depend on needle location or even needle insertion. Since these variables are those that define acupuncture, the only sensible conclusion is that acupuncture does not work. Everything else is the expected noise of clinical trials, and this noise seems particularly high with acupuncture research. The most parsimonious conclusion is that with acupuncture there is no signal, only noise.

Given the utter lack of evidence supporting the effectiveness of acupuncture for anything, including depression, pain, and other medical issues, there is no reason to think that this study has provided us with any evidence to change the scientific consensus about acupuncture–it is a pseudoscience with no clinical benefit. Acupuncture continues to show no clinical benefit in a multitude of situations, and it really should not be used as a frontline therapy in most studied clinical situations. I know some people will insist on using it, and will claim some incredible benefits. Except that’s just anecdote.

Key citation:


The Original Skeptical Raptor
Chief Executive Officer at SkepticalRaptor
Lifetime lover of science, especially biomedical research. Spent years in academics, business development, research, and traveling the world shilling for Big Pharma. I love sports, mostly college basketball and football, hockey, and baseball. I enjoy great food and intelligent conversation. And a delicious morning coffee!