This news release from the American Medical Society for Sports Medicine (AMSSM) describes a therapy called viscosupplementation that involves injecting hyaluronic acid, a gel-like fluid, that acts as a lubricant to alleviate pain in people with knee osteoarthritis. In this case the target audience is senior citizens.
Because the subhead of the release describes it as a “New Scientific Statement” the ASSM might be forgiven for the medical jargon used throughout the release. This clearly wasn’t written for the general public. For example, the release doesn’t explain the term “viscosupplementation,” which is what this release is promoting. We hope health journalists take care when re-interpreting the language for the older Americans considering their many options for treating a common ailment like painful knees.
The release offers no discussion on costs of viscosupplementation or insurance coverage restrictions. The benefit data is limited and there are no mention of harms. The article upon which this recommendation is based won’t be published until January 2016 which makes these limitations much more critical.
Osteoarthritis of the knee is the most common form of arthritis and can be seen as a normal part of aging and of “wear and tear” of the body. It occurs most often in people over age 50 and more often in women than in men. It’s degenerative, getting worse over time.
With the aging of the US population, especially considering the crush of baby boomers, the subject of how best to manage the pain and disability seen with osteoarthritis of the knee becomes important. While viscosupplementation has been available for many years, the majority of randomized clinical trials have not demonstrated a consistent or important benefit to either pain level or functionality from this therapy. A terse, vaguely worded and incomplete release does little to inform either the general public or the clinical community.
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.”
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.
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.
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.
The statistics provided are fairly consistent to what is given out by the NIH and Centers for Disease Control and Prevention so we see no disease mongering here.
The information is being provided by the American Society for Sports Medicine, a multidisciplinary group of clinicians who specialize in sports medicine. There is a potential for an inherent bias. In case that needs spelling out the potential bias is that the association may be seeking new patients beyond its athlete patient base, and expanding into the aging population of “baby boomers” who have the greatest incidence of knee osteoarthritis.
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?
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.
Suggesting that viscosupplementation, which is not a new treatment, should be a mainstay of treatment based on the argument that some may benefit is certainly a novel (and a controversial) idea. That recommendation puts it at odds with what the American Academy of Orthopaedic Surgeons says. Here’s what the AAOS has to say about viscosupplementation, “We cannot recommend using hyaluronic acid (HA) for patients with symptomatic OA of the knee,” with a “Strong” rating, based on supporting evidence from 3 high-quality and 11 moderate-quality research studies that met the inclusion criteria.
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.