Physical Therapy May Not Be Helpful for Osteoarthritis

Lara C. Pullen, PhD

May 27, 2014

Physical therapy did not improve pain or function in patients with hip osteoarthritis relative to sham treatment in a randomized, placebo-controlled trial. Moreover, the multimodal physical therapy program was associated with relatively frequent, but mild, adverse effects.

Kim L. Bennell, PhD, from the School of Health Sciences, University of Melbourne, Australia, and colleagues published the results of their trial in the May 21 issue of JAMA. The study was designed to detect clinically relevant differences among 102 patients randomly assigned to receive either physical therapy or sham therapy.

The investigators defined clinically relevant improvement as a change of 18 mm on a 100-mm visual analog pain scale and 6 units out of 68 on a physical function index.

"We minimized potential for bias by including a credible sham treatment, concealing treatment allocation, and blinding the participants, outcome assessor, and biostatistician. Participants had radiographically confirmed hip osteoarthritis and a sufficient level of pain and physical dysfunction to ensure ample scope for improvement," the authors write. Therapists were not blinded in the trial.

The investigators documented 85% adherence rates to home exercise. Both groups experienced clinically relevant benefits from their time with the therapist. The authors believe that the documented improvements were unlikely to be a result of spontaneous recovery.

However, they found no statistically significant difference between groups with regard to change on pain and physical function scales. Any differences, although not clinically significant, favored the sham group and not the active group. For example, measurement of the improvements in pain yielded a between-group difference of 6.9 mm, favoring sham treatment (95% confidence interval, −3.9 to 17.7 mm).

"We found that a 12-week multimodal physical therapy treatment typical of current practice for people with symptomatic hip osteoarthritis, did not confer additional benefits over a realistic sham treatment that controlled for the therapeutic environment, therapist contact time, and home tasks. Both groups showed significant improvements in pain and function following treatment. The active group reported a significantly greater number of adverse events although these were relatively mild in nature," the authors write.

A recent Cochrane review of hip osteoarthritis documented small benefits of exercise for pain and physical function when compared with no treatment. Another recent study found that manual therapy or exercise was beneficial when compared against usual general practitioner care. The combination of the 2 therapies was found to be less effective than either one alone.

The current study represents, however, the first placebo-controlled trial of physiotherapeutic interventions for hip osteoarthritis. Although previous studies have compared exercise and/or manual therapy with standard care, education, or another therapy, the current study was designed to control for regular intensive contact with a physical therapist.

The results of the current study are consistent, however, with previous studies that have documented significant placebo effects in hip osteoarthritis. They are also consistent with previous research that the team has done with other manifestations of osteoarthritis.

"We have tested other multimodal physical therapy programs for knee osteoarthritis and for shoulder chronic rotator cuff pathology, comparing against the same placebo treatment we used in the current study. Both of these studies found similar results to the current study in that both the active and sham treatment groups showed improvements but no significant differences between them," Dr. Bennell told Medical Medscape News.

Although the investigators are confident their findings are real, they acknowledge that drawing clinical recommendations from the findings is complicated.

"I think the interpretation and clinical meaning of the results warrant further discussion. It seems that receiving the specific physical therapy treatments did not add any greater benefit over simply seeing a caring physical therapist and having positive expectations about treatment. As both groups showed improvements in pain and function over time, this suggests that you can gain benefits for pain and function by simply seeing a physiotherapist, and that the benefits are not tied to the exact treatment that the therapist is administering," Dr. Bennell said.

"The article is [a] well-conducted study," John FitzGerald, MD, from Ronald Reagan University of California, Los Angeles, Medical Center, told Medscape Medical News. "Hip [osteoarthritis] is a harder joint to rehab then, say, a knee. I wouldn't want people to confuse this as [physical therapy] is useless.

This study was funded by the National Health and Medical Research Council, an Australian Research Council Future Fellowship, and an Australian National Health and Medical Research Council Practitioner Fellowship. Dr. Bennell received royalties for an educational DVD on knee osteoarthritis, and she and 1 coauthor received royalties from a commercially available shoe from Asics Oceania. The other authors and Dr. Fitzgerald have disclosed no relevant financial relationships.

JAMA. 2014;311:1987-1997. Abstract


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