Knee injections offer minimal relief from arthritis pain
Injection therapy (also known as viscosupplementation) offers little relief from painful knee osteoarthritis, according to a recent study in the Annals of Internal Medicine. The therapy involves injections of hyaluronic acid, a substance found in joint fluid, to add cushioning in the knee joint and ease symptoms of "wear and tear" osteoarthritis.
Researchers pooled the findings of 89 studies of the injections, involving 12,667 people with knee arthritis. They calculated the overall effect on pain, painful "flare ups," and knee function. The analysis revealed minor improvements in pain and joint function, but noted a small increase in side effects from the injections, such as sudden pain, feeling of warmth, and swelling of the treated joint.
This study summarizes all the medical evidence to date on hyaluronic acid. The findings support the general clinical wisdom, which is that injection therapy—when it works—offers minimal and temporary relief. Also, inserting a needle into a joint always comes with a risk of infection or painful swelling.