Research Review by Dr. Shawn Thistle©


Sept. 2005

Study Title:

Acupuncture in patients with osteoarthritis of the knee: a randomised trial.


Witt C et al.

Publication Information:

Lancet 2005; 366: 136-143.


This is the third study I have reviewed in this section on acupuncture for osteoarthritis of the knee. The previous two, also published in major medical journals (British Medical Journal and Annals of Internal Medicine) demonstrated that acupuncture is effective for pain relief and functional recovery in patients with this common affliction. As the most common form of osteoarthritis, knee OA is a major cause of pain and disability in adults.

This study aimed to assess the efficacy of acupuncture for pain relief and functional improvement in patients with knee OA. To be included in the study, patients had to be between the ages of 50 and 75, and have OA of the knee according to the guidelines set forth by the American College of Rheumatology.

Three study groups were used as follows:
  1. acupuncture group - 146 patients received 12 semi-standardized treatments of 30 minutes duration over 8 weeks using standardized acupuncture points treated with traditional needling techniques (one-time use needles inserted into specific points and manually stimulated at least once during the treatment)
  2. minimal acupuncture group - 76 patients received an intervention involving superficial needle insertion (vs. deep in group 1) at points not in the knee area and thought not to be useful for the treatment of knee pain. The same treatment schedule of 12 sessions over 8 weeks was utilized, and no manual stimulation of the needles was performed during the treatments.
  3. waiting list - 74 patients did not receive any treatment for the 8 week treatment period and then underwent 12 acupuncture treatments as in group 1 over the subsequent 8 weeks.
All groups were permitted to continue any regimen of oral pain medications they were taking prior to the study, however no drugs acting through the central nervous system were allowed. The total follow-up period was 1 year (52 weeks) and the primary outcome measure was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) - a validated and commonly used pen-and-paper questionnaire to assess pain and functional limitation in patients with knee OA.

Pertinent Results:

  1. the patients in the acupuncture group had significantly less pain and better function after 8 weeks that patients in the minimal acupuncture or waiting list groups
  2. after 52 weeks however, the differences between the two acupuncture groups was no longer significant
  3. when weeks 1 and 8 were compared, patients in the acupuncture group had a significant reduction in the number of days requiring pain medication
  4. pain medication use was similar in all groups - therefore likely not contributing to the benefit seen in the acupuncture group
  5. side effects experienced with acupuncture in this study were minimal and non-severe

Conclusions & Practical Application:

This is one of the largest studies done to date in this area of study, and it builds on the existing evidence suggesting that acupuncture is an effective adjunct to pain medications in the treatment of osteoarthritis of the knee.

The fact that the treatment benefit of acupuncture seemed to diminish over time should not be taken as a negative. Short-term pain relief will allow patients to engage in strengthening and conditioning exercises (which have also been shown to independently assist in pain management for this condition). Sometimes all patients need is an interruption in the pain cycle to allow them to exercise, strengthen the area, and lose some weight - all of which can also be beneficial.

The key in interpreting a study like this is to take it in the context of an integrated approach to treating this condition.