Viscosupplementation Injections
Joints, such as the hip, knee, and shoulder, normally contain a small amount of joint fluid. The joint fluid helps provide nutrition for the cartilage covering the bones as well as lubrication between the bones during range of motion. Normal joint fluid contains a substance known as hyaluronic acid. Studies have found that in patients with osteoarthritis (see hip osteoarthritis, knee osteoarthritis, or shoulder osteoarthritis), the amount of hyaluronic acid is diminished. This finding prompted researchers to attempt to treat the symptoms of osteoarthritis by replenishing the hyaluronic acid; this concept is the basis of viscosupplementation injections.
Viscosupplementation injections consist of hyaluronic acid-like fluids which are injected directly into the arthritic joint. Studies have shown that viscosupplementation injections provide significant pain relief in patients with mild to moderate osteoarthritis. Although the precise mechanism of action is unclear, these injections seem to have anti-inflammatory and pain-relieving properties. In addition the viscosupplementation fluid is thought to act as both a lubricant and a shock-absorber. Their beneficial effects may last for several months or longer. Currently these injections are approved by the FDA for use in patients with knee osteoarthritis, but research is being conducted in other joints, such as the hip, ankle, and shoulder.
Several different companies make viscosupplementation products, such as Synvisc ® and Hyalgan ®. Depending on the particular product used, the injections are given either as a single shot, or a series of shots (ranging from 3-5) given one time per week.
It is important to realize that unlike steroid injections, viscosupplementation injections do not provide immediate relief. The beneficial effects may not become apparent for several weeks. For the first 1-2 days after the injection, you should avoid excessive activity, such as prolonged standing or walking, heavy lifting, or jogging.
For more information about viscosupplementation injections, please feel free to talk to one of the doctors at Arizona Orthopedic Surgical Specialists.