The evidence supporting acupuncture for relieving knee pain is mixed.
Traditional Chinese acupuncture involves inserting needles at specific points in the body, in the belief that doing so helps channel a "life force" known as Qi.
In modern Western acupuncture, it is believed that the needles stimulate nerves under the skin, producing pain-relieving endorphins. The treatment is now also offered in a non-penetrative form, where low-intensity lasers are applied to acupuncture points.
In scientific trials, the outcomes of participants receiving acupuncture are compared with the outcomes of participants receiving "sham acupuncture," which usually involves the application of retractable, non-penetrating needles to points of the body not used in standard acupuncture.
Despite its increasing popularity as an alternative therapy, trials have shown that the evidence supporting acupuncture for relieving knee pain is mixed.
A 2006 study of 1,007 patients with knee pain found that although 53% of participants receiving acupuncture reported less pain and improved function at 26 weeks, so did 51% of the participants receiving sham acupuncture. Also, 29.1% of patients who received no acupuncture in that study reported less pain and better function.
In 2010, a study published in Arthritis Care & Research similarly found that needle acupuncture and sham acupuncture were about the same in terms of outcomes for patients with osteoarthritis of the knee.
In the new study, researchers from the University of Melbourne in Australia randomly assigned 282 chronic knee pain patients aged 50 years and older to either receive needle acupuncture, laser acupuncture, sham laser acupuncture or no acupuncture. In sham laser acupuncture, the laser is inactive, and neither the participants nor the acupuncturists in the trial knew when the laser acupuncture was sham or active.
'No significant difference' between acupuncture and sham acupuncture outcomes
After 12 weeks of treatment, the needle acupuncture group and sham acupuncture groups reported some improved physical function compared with the group who received no acupuncture. Participants receiving either needle or laser acupuncture also reported modest improvements in pain control. However, neither pain nor physical function were improved after 1 year.
In terms of knee pain and physical function, the researchers found no significant differences between acupuncture and sham laser acupuncture.
The researchers also found no significant differences in secondary outcomes - such as quality of life - between participants who had active or inactive acupuncture. The team did find that pain on walking improved in the needle acupuncture group at 12 weeks, but this was not maintained at the 1-year follow-up.
The authors think that a number of incidental factors may influence outcomes, including:
- Treatment setting
- Patient expectations and attitudes (such as optimism)
- Acupuncturist's confidence in treatment
- Patient and acupuncturist interaction.
"In our study, benefits of acupuncture were exclusively attributed to incidental effects, given the lack of significant differences between active acupuncture and sham treatment. Continuous subjective measures, such as pain and self-reported physical function, as used in our study, are particularly subject to placebo responses.
In patients older than 50 years with moderate or 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."