Does viscosupplementation for knee osteoarthritis in seniors really do the job?

Does the news release adequately discuss the costs of the intervention?

Not Satisfactory

Given the statistics on the incidence of osteoarthritis of the knee provided in the release, the cost of viscosupplementation is important. The costs of the material (technically, hyaluronic acid derivatives are medical devices) varies depending on which is chosen but costs range between $300 to $500 per injection.  Since osteoarthritis of the knee is a chronic condition, the durability of the injection is an important aspect of costs. Clinical trials suggest that when it is effective, the duration is varied ranging from weeks to up to six months.

According to the American Academy of Orthopedic Surgeons web page, an organization that does not specifically endorse viscosupplementation, “If the injections are effective they may be repeated after a period of time, usually 6 months.”

Does the news release adequately quantify the benefits of the treatment/test/product/procedure?

Not Satisfactory

The release is nearly silent on the quantification of benefits of viscosupplementation. It does state, “AMSSM RECOMMENDS viscosupplementation injections for Kellgren and Lawrence (KL) grade II-III knee osteoarthritis in those patients above the age of 60 based on HIGH quality evidence demonstrating benefit using OMERACT-OARSI Responder Rating but the evidence should be downgraded due to indirectness for those under 60 years of age.”

What exactly is the high quality evidence? How is it determined? Does it include functional as well and pain levels in the assessment? The reader is simply advised this is high quality evidence.

There is also no mention of the longevity of any benefits from viscosupplementation. Does the lubrication, if it has a positive effect, last months or years? How many? There is also little in the way of qualification. Who best qualifies for this treatment?

To its credit the release does note that this recommendation appears to fly in the face of all of the evidence from clinical trials. This fact is underscored by a statement from the first author, “We do not treat groups of people we treat individuals,” said Dr. Thomas Trojian, Lead Author and Past AMSSM Board of Director.”

Randomized clinical trials are the recognized gold standard for medical interventions. Trials are designed to look at populations and not at individuals per se. All of these clinical trials are likely to have a group of responders to the intervention. In the case of failed trials, the group represents a subset. Since some people received a benefit, but the majority did not, this doesn’t seem like sound ground to stand on.

Does the news release adequately explain/quantify the harms of the intervention?

Not Satisfactory

It seems intuitive that injection of a solution into the joint space of the knee should have some downsides. Indeed, a 2012 meta-analysis of 89 clinical trials involving over 12,000 subjects published in Annals of Internal Medicine concluded, “In patients with knee osteoarthritis, viscosupplementation is associated with a small and clinically irrelevant benefit and an increased risk for serious adverse events.”

Common side effects of short duration following viscosupplementation include swelling, and feelings of pain and warmth at the injection site. Serious but rare complications include infection, allergic reaction and bleeding.

Does the news release seem to grasp the quality of the evidence?

Not Satisfactory

The quality of the evidence is limited to the few comments related to the “network meta-analysis.” We are not provided with any details on the methods, number of patients followed, what metrics were used to determine efficacy (other than the acronym) or how long people were followed. We’re not told why this is deemed a higher quality therapy for older people, just that it is. We’ll have to wait until the actual article is published in January 2016 to find out.

Does the news release compare the new approach with existing alternatives?

Not Satisfactory

The release states that “people are more likely to show clinical improvement with viscosupplementation over placebo (saline) and intra-articular steroids. This is different than studies recently published that say the average response differs.” Unfortunately, the release doesn’t provide any data supporting that claim.

Reviewers agreed that most every credible source of information on the management of osteoarthritis of the knee suggest a step-wise progression of treatments including weight reduction, braces, analgesics, and the like.  While the release does mention steroid injections it does so dismissively.

Weight loss and strengthening exercises are also mentioned as initial management recommendations, but are quickly glazed over because of “controversial” treatment aspects. What is controversial about current OA treatment?

Does the news release establish the availability of the treatment/test/product/procedure?

Not Satisfactory

The viscosupplementation procedure may be available at many clinics nationwide. We don’t know so we are rating this Not Satisfactory. To be complete the release could have also noted that insurers place some important restrictions for payment and that  Medicare coverage may vary among states.

Does the news release include unjustifiable, sensational language, including in the quotes of researchers?

Not Satisfactory

We think the phrase “high quality evidence” was unjustified language in this release because there was no evidence provided. It’s nearly unheard of for a medical association to offer practice “guidance” or a specific treatment recommendation that changes practice without providing copious data to back up that recommendation.