Results of a randomised trial in this week's issue of The Lancet suggest that acupuncture could reduce pain and improve joint functioning in the short-term for people with osteoarthritis of the knee.
Osteoarthritis most frequently affects the knee joint. Despite a limited evidence base, arthritis patients are increasingly turning to acupuncture, especially as side-effects of non-steroidal anti-inflammatory drugs are common and wide-ranging.
Around 300 patients with chronic osteoarthritis of the knee were randomly assigned to acupuncture, minimal (sham) acupuncture (superficial needling at non-acupuncture points), or a waiting list control.
Patients were allowed to use non-steroidal anti-inflammatory drugs throughout the study. Physicians administered acupuncture and minimal acupuncture in 12sessions over 8 weeks.
Patients completed questionnaires at the start of treatment, and after 8 weeks, 6 months, and 1 year. Analgesic use was similar for patients in the three groups. After 8 weeks, patients given acupuncture had a substantially lower score on an established osteoarthritis index than patients in the control group (26 points and 50 points, respectively).
Minimal acupuncture also had short-term benefit compared with no acupuncture (36 points on the osteoarthritis index). However, at 1-year follow-up there was no significant difference in scores between the three groups. Lead investigator Claudia Witt (Charite University Medical Center, Berlin, Germany) comments:
“Acupuncture treatment had significant and clinically relevant short-term effects when compared to minimal acupuncture or no acupuncture treatment in patients with osteoarthritis of the knee. We now need to assess the long-term effects of acupuncture, both in comparison to sham interventions and to standard treatment.”
In an accompanying Comment, Andrew Moore (Pain Research, University of Oxford, UK), states: “The bottom line from Witt and colleagues' large, long, and high-quality study of acupuncture for knee osteoarthritis is that doing something is better than doing nothing.”
However he cautions that it is too soon to draw firm conclusions from the current study: “We are still some way short of having conclusive evidence that acupuncture is beneficial in arthritis or in any other condition, other than in a statistical or artificial way. There is limited evidence of effect and, with exceptions, of cost-effectiveness. Most importantly, the need for needles is still in doubt.”
The more data on accupuncture's usefulness we have, the clearer its mechanism may become. This is, in part, because the sites where an accupuncture regime is indicated for a particular pain turns out to vary greatly between conditions --sometimes its on the spot of the pain, other times it is applied elsewhere on the body in accordance with a traditional theoretical constellation of points (in such cases the relevant neuroanatomy can be less clear).
Along with certain kinds of transcutaneous electrical nerve stimulation, accupuncture is a 'counter-irritation analgesia'. We know that these forms of analgesia involve both opioid and non-opioid systems (for example, naloxone --an opioid antagonist-- has been shown to reduce accupuncture's analgesic effects). The mechanisms of the notorious placebo effect and hypnotic analgesia also play some role in the effects of accupuncture.
See Price and Mayer's 1995, "Evidence for endogenous opiate analgesic mechanisms triggered by somatosensory stimulation (including accupuncture) in humans." Pain Forum 1995, 4(1) 40-43.
Hypnotic analgesia and the placebo effect do have a good deal of theoretical importance for us philosophers (the former is especially useful in understanding why pain is bad). Thus the more light accupuncture sheds on these topics, the better for us.
Oh, and the empirical explanations are always nice for smacking down those who claim it involves 'mind-over-matter' in some metaphysical sense. Though you, gentle reader, don't believe that should be necessary. Right?