The knee, another poorly designed joint, is subject to all kinds of abuse. In March of 2017, we reviewed investigations and surgical treatments of knee pain - in particular arthritis, meniscal tears and arthroscopy, with activity, topical NSAIDS and intra-articular steroids injections as possibilities for treatment.
Another possible treatment that has been around for many years with varying degrees of supportive evidence is Viscosupplementation – hyaluronidase (Synvisc), hyaluronan and hylan (HA) products.
A 2006 Cochrane review (available in our Quick Links section) concluded that "Viscosupplementation is an effective treatment for osteoarthritis (OA) of the knee with beneficial effects: on pain, function and patient global assessment; and at different post injection periods but especially at the 5 to 13 week post injection period. Overall, the aforementioned analyses support the use of the HA class of products in the treatment of knee OA."
Tools for Practice (sponsored by the Alberta College of Family Physicians [ACFP]) is a biweekly article summarizing medical evidence with a focus on topical issues and practice modifying information with the content written by practising family physicians.Their 2016 review was entitled:
Viscosupplementation (Hyaluronic Acid or Hylan): Cushioning the Blow (To Your Wallet)?
See our Quick Links section for a copy of this article.
Their Bottom Line: "Research on Viscosupplementation (hylan or hyaluronic acid) for knee osteoarthritis has frequently been of poor quality and has exaggerated effectiveness. The best evidence indicates no meaningful benefit (if any at all) with potential adverse events (including cost)."
Their review emphasized the following limitations:
- No difference versus intra-articular corticosteroid;
- Placebo injections similar to Viscosupplementation;
- Negative trials less likely to be published;
- The fact that statistical significance, does not necessarily imply clinical significance, or clinical importance;
- While the conclusions of some systematic reviews are positive, i.e. pain reduction at 8 to 12 weeks, clinically meaningful differences are often not discussed or rarely attained;
- Higher quality studies (>100 patients, proper randomization, or blinded outcome assessor) found no clinically meaningful improvement in pain or function.
- And of course, the adverse effect of lightening the wallet by $500.