News Flash: Injections of Hyaluronic Acid May Do Your Knees More Harm Than Good.
That, at least, was the conclusion of a “meta-analysis” by Swiss researchers of 89 clinical trials that looked at the effectiveness of “viscosupplementation.” This procedure aims to bolster a knee pain sufferer’s synovial fluid, which when healthy is a viscous lubricant that acts like a cushion too. When unhealthy, it thins out and performs its essential functions poorly.
The Swiss researchers found that, in 18 large-scale trials, viscosupplementation made such a small difference as to be “clinically irrelevant.” What’s more, some studies suggest the procedure can lead to a higher risk of cardiovascular and gastrointestinal problems.
So that’s settled?
Along comes a new meta-analysis of 29 studies that finds “intra-articular hyaluronic acid injections provided significant improvement in pain and function compared to saline injections.” The authors of this analysis note that all products in these studies were FDA-approved, unlike in the earlier Swiss investigation.
So whose meta-analysis is correct?
Well, the most recent one has a couple of big red flags that should give anyone pause.
* Follow the money.
The end of the Business Wire release for the latest meta-analysis contains an interesting disclosure:
The meta-analysis was supported by the Hyaluronic Acid Viscosupplementation Coalition, a collaborative of hyaluronic acid injection marketers.Hmm. That doesn’t smell good.
Let’s face it: Viscosupplementation has grown into a sizable medical business. When a meta-analysis claims that this procedure -- which a number of companies have probably spent millions of dollars developing and testing products for -- is useless, well, what do you expect them to do? Fight back.
Now it could be that the first meta-analysis got everything all wrong. Sure, that’s possible. But I’d rather that a set of neutral, disinterested researchers determine that than a couple of what appear to be Phd consultants.
And how was their meta-analysis “supported” (a lovely weasel word, with positive connotations and an utter lack of specificity)? Were they paid to do the meta-analysis? And what guidance were they given by the coalition, if any?
* Consider the source.
At least the results of the meta-analysis were published in the New England Journal of Medicine, right?
Uh, not quite.
In fact, I was left scratching my head after reading the title of the publication: Clinical Medical Insights: Arthritis and Musculoskeletal Disorders. I’ve perused lots of medical papers related to knee pain and treatments for the problem. So I’m familiar with many of the names of publications. But not this one.
Who’s behind Clinical Medical Insights (it appears a number of sister publications use this same moniker)? This is where things get interesting.
An outfit called “Libertas Academia” puts out the Clinical Insights series. It belongs to the ranks of so-called open access publishers. In theory, the concept of “open access” sounds great, especially if you (like me) have run headfirst into a paywall when trying to get a copy of the published results of a particular medical study. What’s more, the per-article rates for regular journals are invariably steep ($30 to $40 say). But with open access, the publisher makes the content free.
Great -- except where does the money come from to support such an operation? Answer: the authors seeking publication. Libertas Academia says here that it charges from $950 to $1,980 as an “article processing fee.” (Which raises a curious question: Who paid for the report on this latest meta-analysis that found positive benefits of viscosupplementation? Maybe the Hyaluronic Acid Viscosupplementation Coalition?)
If this business model is starting to make you squirm, you’re not the the only one. This writer, in reviewing nine open-access publishers (including Libertas Academia), labels them “predatory.” He explains, “Their mission is not to promote, preserve, and make available scholarship; instead, their mission is to exploit the author-pays, open-access model for their own profit.” The publishers provide “little or no peer-review,” he alleges.
Also they “spam” academics, inviting them to submit articles which sometimes aren’t even in their field, according to this frustrated researcher who said he got eight spam e-mails from Libertas Academia, despite requests to stop. Not surprisingly, open-access publications have acquired the nickname “vanity journals.”
If you’re still not convinced, check out this tale of a nonsense-filled, spoof academic paper submitted by a Science magazine editor to open-access journals. More than 100 accepted it despite errors so blatant, “Any reviewer with more than a high-school knowledge of chemistry and the ability to understand a basic data plot should have spotted the paper's short-comings immediately.”
Anyway the point here:
Just as not all knee studies are created equal, so all meta-analyses are not either. Caveat emptor (or whatever the “patient beware” version of that Latin saying is). Viscosupplementation may help your particular knees, true. But be wary of “research” supported by makers of the products. They may not be the best neutral source of information, to say the least.