Five controlled trials, with a total of 205 patients, were included in the review.
Effectiveness of acupuncture.
One study reported an 85% subjective improvement in 36 of 42 knees in their study of 29 patients. There was also a statistically significant improvement in HSS knee function score over 3 weeks. Of the 19 knees that had the best immediate effect, only six showed long-term effects.
One study reported that 80% of the patients experienced pain relief at week 16 and 56% of patients indicated subjective improvement. The long-term results indicated that acupuncture continued to deliver a reduction in pain, an increase in quality of life, and a reduction in the use of non-steroidal anti-inflammatory drugs. However, 26 of the 32 patients dropped out before the end of the 49-week study period.
A randomised controlled trial (RCT) reported statistically significant decreases in pain, stiffness and functional indexes in both the control (sham acupuncture using treatment points approximately 1 inch away from the real acupuncture points) and treatment groups. However, there was no significant difference between the groups. Patients who experienced 'The-Chi', a sensation of numbness and pressure created by the acupuncture needles, reported better results than those who did not, and men reported better results than women.
An RCT that randomised patients to either unilateral (in the most painful knee) or bilateral acupuncture treatment found that both interventions were equally effective in reducing pain and increasing functional loss associated with OA of the knee. At the 6-month follow-up there was no significant difference in pain.
Another RCT with a 'no treatment' group found significant improvements in the treatment group, compared with the control group, for HSS Knee Score, VAS pain score, 50-metre walk time and 20-step climb time.
Side-effects.
In one study three patients reported mild effects such as increased pain, nausea or dizziness, as well as more serious effects of a large haematoma that disappeared in 14 days and a vasovagal attack. In another trial three patients reported minor bruising at the needle insertion points. Beneficial side-effects, including improved backache, better sleep and improvement in circulation, were reported in the same trial.