Tai Chi May Be as Good as PT for Knee Arthritis Pain

Janis C. Kelly

May 18, 2016

The first randomized head-to-head comparison of tai chi and conventional physical therapy (PT) in patients with knee osteoarthritis (OA) shows equally good pain relief with either intervention, researchers report in an article published online May 17 in the Annals of Internal Medicine. The researchers also show that tai chi was more effective than PT at relieving depression and improving the physical component of quality of life.

The authors note that the usual drug treatments (nonsteroidal anti-inflammatory drugs or acetaminophen) for knee OA often fail to relieve symptoms and have been associated with serious adverse effects. PT is routinely included in knee OA treatment regimens and produces moderate improvements in pain and physical functioning, but has an uncertain effect on psychological well-being, as well as limited durability.

"Identifying new and effective treatments for patients with knee osteoarthritis is an urgent clinical and public health priority," the authors write.

Tai chi, which combines meditation; slow, gentle movements; deep diaphragmatic breathing; and relaxation, has long been a promising candidate in knee OA. The researchers, led by Chenchen Wang, MD, previously reported that tai chi improved pain, physical function, depression, and health status in patients with knee OA compared with wellness education and stretching..

In the current study, the team enrolled 204 patients aged 40 years or older who met American College of Rheumatology criteria for symptomatic knee OA and had radiographic evidence of tibiofemoral or patellofemoral OA. At baseline, all participants had scores of 40 or greater on at least one of five questions on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale.

Patients were randomly assigned either to tai chi (60-minute sessions two times per week for 12 weeks) or to standard physical therapy (30-minute sessions two times per week for 6 weeks, followed by 6 weeks of home exercise monitored by weekly telephone calls and by standardized forms reporting frequency, exercises completed, adverse events, and adherence).

The primary outcome measure was WOMAC score at 12 weeks. Secondary outcomes measured at baseline and at 12, 24, and 52 weeks included WOMAC physical function and stiffness scores, Patient Global Assessment score, Beck Depression Inventory-II score, physical and mental components of the 36-item Short Form Health Survey, Arthritis Self-Efficacy Scale score, and results of the 6-minute and the 20-m walk tests.

The study was designed with 80% power at the 0.05 significance level to test tai chi for noninferiority to PT (<20-point difference on WOMAC pain score) for the primary outcome, and then for superiority (>20-point difference) if noninferiority were established

The authors write, "The upper limit of the 95% CI for the 12-week WOMAC pain score indicated that physical therapy was highly likely to be superior to tai chi by no more than 10 points, well within the noninferiority margin of 20 points."

They continue, "The tai chi group showed greater improvement than the physical therapy group for most outcomes, but these differences were not statistically significant except for the 36-item Short Form Health Survey physical component summary and the Beck Depression Inventory-II scores."

WOMAC pain scores at 12 weeks had dropped from 254.8 at baseline by 167 points (95% CI, 145 - 190 points) with tai chi and from 252.9 at baseline by 143 points (95% CI, 119 - 167 points) with PT (P = NS).

Improvements in most secondary outcomes were also similar at 12 weeks, and all outcomes were similar at 24 and 52 weeks. Furthermore, similar proportions of patients performing tai chi and receiving PT met Osteoarthritis Research Society International response criteria: 72% vs 63% at 12 weeks, 67% vs 48% at 24 weeks, and 49% vs 51% at 52 weeks.

Kelley Fitzgerald, PT, PhD, who was not involved in the study, told Medscape Medical News, "Both groups had good outcomes, and it is nice to know that tai chi might represent a reasonable option for patients with knee OA who would rather attend tai chi classes than have PT." Dr Fitzgerald is professor and associate dean of graduate studies, University of Pittsburgh School of Health and Rehabilitation Services, Pennsylvania.

Although the two approaches were substantially equivalent in the context of this study, Dr Fitzgerald warned that the study design does not support the conclusion that tai chi and PT are fundamentally equivalent in knee OA, as patients in the tai chi group had four times as many contact hours as those assigned to PT (24 hours of supervised sessions vs 6 hours).

Dr Fitzgerald also said that a PT schedule of two sessions per week for 6 weeks (as in the study) is fairly typical, but that in his clinic, sessions are typically 45 minutes to 1 hour, rather than the 30 minutes in the study intervention. "There could be some dosing issues, but even so, the patients in both the tai chi and the PT groups did well," he said.

The authors explain, "This comparative effectiveness trial of 2 active therapies showed that despite a substantial difference in intensity of contact for participants between groups, Tai Chi and physical therapy each confer clinically significant improvements in pain and related health outcomes by 12 weeks, with the benefits maintained up to 52 weeks. Both treatment groups showed similar improvement in most secondary outcomes, but the Tai Chi group had significantly greater improvements in depression and the physical component of quality of life. Of note, the benefit of Tai Chi was consistent across experienced instructors treating patients with knee osteoarthritis."

As reported by Medscape Medical News, the authors presented data from this study at the American College of Rheumatology 2015 Annual Meeting.

The study was supported by the National Center for Complementary and Integrative Health of the National Institutes of Health. Dr Wang has disclosed no relevant financial relationships. Other coauthors reported grants from various pharmaceutical companies outside the submitted work and personal fees from pharmaceutical companies outside the submitted work. Dr Fitzgerald has disclosed no relevant financial relationships.

Ann Intern Med. Published online May 16, 2016. Abstract

For more news, join us on Facebook and Twitter


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.