OA Adjunctive Therapies Give Negligible Added Benefit to Exercise

Tara Haelle

March 30, 2023

DENVER – Adding therapies such as acupuncture, electrophysical stimulation, or other interventions to standard exercise therapy does not appear to offer much benefit in pain relief or physical function for patients with knee osteoarthritis, according to a study presented at the OARSI 2023 World Congress. The findings were also published in the Cochrane Database of Systematic Reviews in October 2022.

"The results do not support the use of adjunctive therapies when we add them to exercise for pain, physical function, or quality of life, when compared against placebo, adjunctive therapy, and exercise," Helen P. French, PhD, told attendees at the meeting sponsored by the Osteoarthritis Research Society International. The findings were similar for pain and physical function when comparing adjunctive therapies with exercise against exercise alone, said Dr. French, an associate professor in physiotherapy at the Royal College of Surgeons, Dublin, except that patients using adjunctive therapies reported feeling greater improvement in their global assessments.

Exercise is recommended as a core treatment for osteoarthritis, but some patients or clinicians may be interested in supplementing that therapy with acupuncture, heat therapy, electromagnetic fields, transcutaneous electrical nerve stimulation, braces/orthotics, and other interventions. Various Cochrane Reviews of the evidence exist for these interventions in treating chronic pain in general but not for their use as adjunctive therapies in addition to exercise for osteoarthritis pain.

Researchers therefore assessed the evidence for improvement in pain, physical function, and quality of life for two sets of comparisons: adjunctive therapies plus exercise versus exercise alone, and adjunctive therapies with exercise versus placebo adjunctive therapy with exercise. The review excluded studies looking at medications or supplements.

Pain was assessed with the Numeric Pain Rating Scale (NPRS, 0-10), with an improvement of at least 2 points (15% improvement) representing the minimum clinically important difference (MCID). Physical function was assessed with the Western Ontario and McMaster Universities Arthritis Index (WOMAC, 0-68), with 6 points (15%) considered the MCID, and quality of life was assessed with the SF-36 (0-100), with 6 points (12%) as the MCID.

The researchers identified trials on knee osteoarthritis that included an overall 6,508 participants with an average age ranging from 52 to 83 years. A total of 36 studies evaluated electrophysical agents. Another seven looked at manual therapies; four looked at acupuncture/dry needling or taping; three looked at psychological, dietary, or "whole body vibration" therapies; and two evaluated spa or peloid therapy. Only one trial evaluated foot insoles.

Nearly all the studies (98%) assessed pain, and most (87%) assessed physical function. Only about one in five (21%) assessed quality of life. The improvement in pain from adding adjunctive therapies to exercise, compared with placebo therapies plus exercise, was 0.77 points, or just under a 10% improvement, which fell short of the 15% MCID. Physical function improvement similarly fell short, with an average improvement of 5 points (12%).

In comparisons of exercise plus adjunctive therapies against exercise alone, the improvement from the additional interventions was even lower. Pain improvement was 0.41 points (7%), and physical function improvement was 2.8 points (9%). However, patients' perceptions told a different story: 37% more patients who were using an adjunctive therapy reported feeling that the therapies were successful, compared with patients undergoing exercise therapy alone.

Adverse events were poorly reported in the trials, with only 10 trials reporting them at all, and the researchers found no significant difference in adverse events among the studies reporting them. The most common adverse events were increased pain in the joint with the osteoarthritis, pain elsewhere, or swelling and inflammation. It's unclear, however, whether the pain, swelling, and inflammation were related to the interventions and how serious these effects might have been.

Michelle Hall, PhD, an associate professor in the department of physiotherapy at the University of Melbourne, comoderated the session with this presentation and found it interesting that more than one-third of patients perceived that they did better with the additional therapies even though improvement didn't bear out in their pain or physical function assessments.

"But the other part of that was that the studies were of poor quality, so we can't say with confidence, 'Don't do this therapy because it's not going to work,' " Dr. Hall said in an interview. She said she personally would probably discourage patients from those therapies, "but I don't think the evidence is there for everybody to do that," she added.

Martin Van Der Esch, PhD, of Reade Centre of Rehabilitation and Rheumatology in Amsterdam, also comoderated the discussion and had more concerns about the use of adjunctive therapies in light of the study's findings. He said in an interview that he tended to believe the patients' overall self-reported improvement is likely a placebo effect, and he sees potential harm in that effect. If the pain is not truly decreasing as patients continue using those therapies, then the pain may become a more stable part of the nervous system, "so I think they need to do an intervention which really has evidence in reducing pain, an active approach that means exercising in the right way," Dr. Van Der Esch said. If patients are undergoing therapy whose primary benefit is a placebo effect, "the pain will prolong and become more fixed in the nervous system," shifting the patients toward greater risk of the pain becoming chronic, he said.

"I want to emphasize that we have an ethical role to our management, and it's not ethical to give treatments which have no response and no pain relief except that the patient or the professional believes it will have an effect," Dr. Van Der Esch said.

The research did not involve outside funding. Dr. French, Dr. Hall, and Dr. Van Der Esch reported having no relevant financial relationships.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.