A common jab used to treat osteoarthritis in the knees works no better than a placebo for relieving pain, according to new research. In fact, the injection could actually increase the risk of harmful side effects.
Since the 1970s, doctors have been prescribing shots of hyaluronic acid for joint pain, despite mounting evidence that the treatment does not work as advertised. Some countries even ramped up usage in the last few years.
The gel-like hyaluronic acid is supposed to lubricate joints in a process known as viscosupplementation. Considering more than 560 million people suffer from osteoarthritis in some joint (mostly knees) worldwide, the market for any relief is enormous.
The most recent study, published in the BMJ journal, analyzed 169 published trials and over 9,000 patients in hopes of discovering any sort of long-term trends associated with the injection and a placebo. The researchers’ findings bordered on negligence as the injection repeatedly proved not just worthless, but outright adverse for patients.
“[We] found strong conclusive evidence” that “viscosupplementation is associated with a clinically irrelevant reduction in pain intensity,” the study said.
Some governments are refusing to reimburse costs for the knee injection to encourage patients to look elsewhere for treatment
They also said the treatment is “associated with a higher incidence of serious adverse events,” adding that it is “not only ineffective compared with a placebo but might also be seriously harmful.”
Bruno da Costa of the University of Toronto, who authored this study as well as a similar study in 2012, said the need for more clinical trials has passed. “We don’t need new trials,” he said, pointing out that the latest results were conclusive.
According to da Costa, the injection should only be considered as a last resort moving forward. But when trying to move the glacier that is accepted science, competing interests often stand in the way. For instance, since the team’s 2012 research, several large-scale, industry-funded studies were carried out that found negative results about the treatment. However, none of them ever saw the light of day.
“This is concerning, and perhaps mainly driven by commercial interests,” he said. He also said that between 2009 and 2021, when compelling research was widely available, more than 12,000 patients still received the bunk treatment.
Currently, specialists who prescribe the injections, companies that produce hyaluronic acid, and some patients’ groups oppose the new findings.
Some countries like France do not offer reimbursement for the treatment any longer. But other countries, like the U.S., still happily inject hyaluronic acid into joints without much hesitation. In fact, a quarter of the money that U.S. Medicare spent on viscosupplementation in 2018 went towards treating infections in joints following the injection.