Viscosupplementation (joint lubrication therapy or synovial fluid replacement) is an injection in which a lubricating gel-like substance (hyaluronate) is injected into the knee joint to allow the cartilage surface of the bones to glide over each smoothly. The knee bends an average of 1 million times per year and to facilitate this movement, the joint is naturally filled with synovial fluid which acts as a lubricant and shock absorber. The injection of hyaluronate is used to supplement the synovial fluid which is often deficient in arthritic knees.
In osteoarthritis, the concentration of natural occurring hyaluronate in the synovial fluid is reduced resulting in smaller and less effective molecules. The HA loses some of the lubricating and shock absorbing properties that protect the knee, resulting in joint pain, stiffness and worsening of osteoarthritis.
Examples of Viscosupplements include:
Who benefits from viscosupplementation?
Hyaluronate injections benefit patients with painful osteoarthritis of the knee, and those who have experienced a breakdown of the synovial fluid due to accident or disease. The procedure is highly successful for those who have failed to respond to more conservative treatment. The process involves a series of 3-5 injections into the knee joint over the course of a month or so.
How does viscosupplementation work?
The viscosupplementation injection is administered directly into the knee from a point on the side and under the kneecap. Up to 12 weeks may be required for the injections to take full effect. Patients commonly report pain reduction and increased joint mobility lasting from a few months to over a year.
Researchers are not exactly sure how hyaluronate injections relieve pain. Theories suggest that the injection of supplemental hyaluronic acid may induce the body to produce its own hyaluronate in the knee. Researchers also believe hyaluronate may have anti-inflammatory properties or that the new “lubricant” in the knee reduces inflammation or protects and soothes the nerve endings exposed by the worn cartilage of the arthritic knee.
“As a lifelong runner, these injections have been the only reason I am able to continue doing what I love.”
If you have osteoarthritis of the knee and traditional methods (exercise, physical therapy, weight loss, modalities, pain medications, etc.) have not provided relief, then viscosupplementation may be a great solution. There will be an initial evaluation with your doctor to see if this therapy is right for you. Please contact Legacy Medical Center with questions.