Clinical Question: Is acupuncture effective in decreasing pain and improving function in patients with osteoarthritis of the knee?

Setting: Outpatient (any)

Study Design: Randomized controlled trial (double-blinded)

Allocation: Concealed

Synopsis: The authors enrolled 570 patients who had radiologic and clinical evidence of osteoarthritis of the knee and who had not had any intra-articular injections. The patients were assigned to one of three treatment groups: (1) “true acupuncture” based on the Traditional Chinese Medicine meridian theory to treat knee-joint pain; (2) a sham treatment that mimicked true acupuncture, except that the needles were not actually inserted (i.e., the acupuncture guiding tubes were tapped at sham points, then needles were affixed with adhesive tape at these sites without insertion); and (3) a control group that received six two-hour group education sessions led by a patient education specialist, with follow-up educational materials sent in the mail. Treatment was rendered twice a week for eight weeks, tapering over the next month to one treatment per month, which was continued through the end of the study. This design addresses two issues that have plagued previous acupuncture research by providing a sham treatment group, and a no-treatment group.

Initially, pain scores were an average of 8.9 (of a possible 20) as measured by the Western Ontario and McMaster University Osteoarthritis Index. At week 14, the authors noted a 3.6-unit decrease in pain scores (40 percent improvement) in the true acupuncture group compared with a 2.7-unit decrease in the sham group and a 1.5-unit decrease in the education group. This change with true acupuncture was statistically significant compared with the other two groups. Pain scores continued to improve in all three groups over the course of the study, although true acupuncture scores continued to improve statistically more than the other two groups.

Functional deficit diminished from an average of 32 units (of a possible 68 at baseline) to 19 units at the end of the study. This resulted in an almost 40 percent improvement with acupuncture and was statistically better than the other two groups. Patient global assessment scores also improved in the acupuncture group to a statistically greater extent than in the other two groups. Distance during the six-minute walk and scores on the 36-Item Short-Form Health Survey improved more with true and sham acupuncture treatment than with education, but the results were similar between those two groups.

Bottom Line: Compared with sham acupuncture treatment or no treatment, acupuncture decreases pain scores by an average of 40 percent and similarly improves function in patients who stick with it. The acupuncture used in this study was based on the Traditional Chinese Medicine meridian theory and was employed for the entire six months of the study. (Level of Evidence: 1b)