Approval for the first viscosupplement agent in the United States came 19 years ago. It has been used in different forms for well over two decades in multiple different medical fields ranging from cosmetics all the way to neurosurgery. It also has application to the management of disability and pain from osteoarthritis. It is approved in the United States for knee osteoarthritis specifically, but there are non-FDA-approved joints that have been widely treated – hips and shoulders particularly, but also sacroiliac joints, facet joints, metacarpophalangeal joints and others. There are actually eight products that are marketed and approved by the FDA. Six different products and two that are the same parent compound, but they are in a one-injection regimen as opposed to being multiple injection regimens like most of the others. In the sequence of treatment, viscosupplementation is usually tried after you have already exhausted more conservative management such as basic analgesics as well as physical therapy. There are some potential adverse events, but they are very low in terms of their incidence. One that most widely raises concern is the appearance of pseudoseptic arthritis or pseudoseptic joints, which is an inflammatory reaction that occurs in the injected joint. It’s not really an infection or a septic joint, but an inflammatory response to a foreign entity that is usually self-limited to a day or two.
The evidence for effectiveness is actually quite controversial. There have been a number of different societies that have called into question its efficacy, most notably the American Academy of Orthopedic Surgery. However, there have been other publications particularly a Cochrane database review that was published a couple of years ago that shows their efficacy. One of the biggest challenges is choosing the patient appropriately. There are many different phenotypes of osteoarthritis that may have better or lesser responses to this therapy specifically. Clinicians should know that viscosupplementation represents another option for patients that have osteoarthritis, and pain and disability related to it, one that could have potentially a medication-sparing effect that could be helpful in keeping them functional and avoiding the systemic side effects of medication therapy.