Title:Is the Addition of a Polyol to Hyaluronic Acid a Significant Advance in the Treatment of Osteoarthritis?
Volume: 14
Issue: 3
Author(s): Thierry Conrozier*
Affiliation:
- Department of Rheumatology, Hopital Nord Franche-Comte, Belfort,France
Keywords:
Hyaluronic acid, viscosupplementation, knee osteoarthritis, hip osteoarthritis, mannitol, sorbitol, polyol, antioxidant,
intra-articular injection.
Abstract: Viscosupplementation with intra-articular injections of hyaluronic acid is recommended
as a second line treatment for knee OA, after failure of non-pharmacological modalities and usual
pain killers. Nevertheless there are still controversies regarding clinical relevance of its effects.
Research is looking for the best way to improve the performance of viscosupplementation in order
to obtain a faster, longer-lasting and more pronounced effect. Antioxidants have been assessed in
combination with hyaluronic acid because the injected hyaluronate is rapidly degraded by the reactive
oxygen species, present in large amounts in the OA synovial fluid, limiting its residence time
into the joint. Sorbitol and mannitol which have intrinsic free radical scavenger properties have
been the most studied antioxidants. Sodium hyaluronate and polyols develop together a complex
based on a dense network of hydrogen bonds which do not modify the visco-elsatic properties of
hyaluronic acid. The oxygen free radicals neutralization by mannitol has been proven to delay the
degradation of both linear and cross-linked HA in several in vitro models of oxidative stress. The
antioxidant effect of these polyols may also play a role in accelerating onset of analgesia, as demonstrated
in a double blind controlled trial comparing a mannitol-modified viscosupplement to
regular hyaluronic acid. The addition of mannitol and sorbitol to hyaluronic acid does not alter the
safety and local tolerability. In summary, adding a polyol to hyaluronic acid may improve the effects
of viscosupplementation by reducing the rate of degradation of HA leading to a faster effect
on pain relief without increasing the risk of adverse effect.
