An open-label trial comparing exercise and education with intra-articular injections of saline in patients with knee osteoarthritis has found the short term outcomes are equivalent.
The Danish study randomised 206 patients with knee pain and radiographically-verified tibiofemoral OA to a structured 8-week exercise and education program delivered by physiotherapists or the intra-articular saline injections.
The primary outcome, the change from baseline in the pain subscale of the Knee injury and Osteoarthritis Outcome Score questionnaire (KOOS) at week 9 and week 12, were statistically equivalent.
“The key secondary outcomes all respected the predefined criteria for equivalence, although the group difference in the Participant Global Assessment was statistically in favour of the exercise and education group.”
The study, published in Annals of the Rheumatic Diseases, said the numbers, rates and severity of adverse events and their relationship to trial treatment were similar across both groups of patients.
“This study is the first to compare a widely implemented exercise and education programme with an open-label placebo, and the results show that the exercise and education programme provides equal effects as an open-label application of intra-articular saline known to be associated with contextual factors and placebo responses,” it said.
The authors, including Professor David Hunter from the Institute of Bone and Joint Research at the University of Sydney, said it was possible that the placebo response to intra-articular saline was higher than that of exercise and education.
As well, it could be argued the dissimilarities of the two interventions limit their comparability.
“However, due to the inherent unblindable nature and unknown ‘active components’ of exercise and education, it is not possible to deliver a completely inactive version.”
“We sought to bypass this by applying an open-label study design and comparing exercise and education to intra-articular saline that is commonly used as placebo comparator and easier to monitor than oral or topical placebos.”
They said their findings support that of other recent trials of exercise such as the START RCT which found muscle strengthening exercise in knee OA were not more effective than a control group.
“These findings raise important questions about mechanisms of action as well as the continued widespread recommendation of exercise and education in the management of knee OA,” they concluded.
Professor Hunter told the limbic that he would still encourage exercise but as part of a composite intervention.
“It’s not that exercise provides no benefit but that the benefit above any placebo or contextual effects is small. Weight loss studies where they have had appropriate controls, do demonstrate modest effects as well.”
“It calls for multidisciplinary interventions, so not just exercise on its own, but thinking about getting people active, getting people to lose weight, and using medication.”
“But it also calls us out as researchers to say there is a lot we can do to improve the lot of patients over and above placebo. There are some promising treatments on the horizon that modify the disease as well as the symptoms…for example, there might be injections that help regenerate joint tissue.”
“I don’t want to give the perception that there is nothing that can be done for osteoarthritis because there are a lot of treatments that have demonstrated benefits including small benefits from exercise, benefits from physical activity, some benefit from weight loss. But we are not going to see big benefits and we are going to see challenges with adhering to that behavioural change long term as well.”
“I’m not writing exercise off; it’s one part of what we should be doing for everybody but on its own, it’s not going to be enough.”