Hyaluronic Acid (Viscosupplementation)
Nowadays, hyaluronic acid injections (viscosupplementation) are widely used for cartilage defects and osteoarthritis pain relieve. Hyaluronic acid is a natural ingredient of synovial fluid and articular cartilage. The main role of hyaluronic acid is joint lubrication in order to avoid friction of the bony articulating surfaces. In addition, hyaluronic acid contributes to some extent to load absorption.
It has been demonstrated that patients with articular cartilage defects and osteoarthritis (figure 1), hyaluronic acid is decreased in the affected joint. Locaql injection of hyaluronic acid (viscosupplementation) could be used in these cases for pain relieve. In addition, hyaluronic acid may have an anti-inflammatory effect and stimulates the production of original hyaluronic acid from the body.
The injection is carried out in the medical office under ultrasound guidance to ensure safety and effectiveness. In case of effusion, the joint should be aspirated prior to hyaluronic acid injection. Sports and intense physical activity are forbidden for 48 hours after the injection. Mild joint effusion may be noticed the day after the injection, that gradually subsides.
There are various products of hyaluronic acid in the market. In most of these products one injection every week for 3-5 weeks is needed for optimal outcome. Recently, new products of highly concentrated acid hyaluronic acid, that require only one injection, are available. The clinical result is maximized at 12 weeks after injection and lasts for several months. In cases of early osteoarthritis the benefits of hyaluronic acid injection are more noticeable.