Results of multiple studies have put a damper on fluid injections for osteoarthritis of the knee. Researchers believe the injections simply don't work. For some patients, this will be a huge disappointment. Based on my experience, I'm not surprised at the outcome.
The umbrella study considered data from 89 studies, according to the Washington Post. The goal was assessing the effectiveness of fluid injections, known as viscosupplementation, to relieve the symptoms of osteoarthritis of the knee. Subjects were 12,667 adults chosen randomly.
The injected material was either hyaluronic acid -- found in synovial fluid that cushions joints -- or a placebo. Some subjects received no treatment.
Osteoarthritis is the most common form of arthritis. Around 27 million Americans 25 and older have this disorder, says the National Institute of Arthritis and Musculoskeletal and Skin Disorders.
The disease destroys the surface layer of cartilage, the tissue that covers the ends of bones and cushions joints from physical movement. As cartilage wears away, bones underneath rub together, causing pain, swelling, and eventual loss of motion.
Patients who undergo viscosupplementation receive a series of injections containing hyaluronic acid in the knee joint to lubricate it. The U.S. Food and Drug Administration approved it in 1997 specifically for osteoarthritis of the knee, according to the American Academy of Orthopaedic Surgeons. Several brands are available. The length of relief varies, up to months.
After four months, patients in the 89 studies who received one or more injections of hyaluronic acid reported less pain than other subjects. However, scientists deemed the change clinically irrelevant. They found no improvement as far as use of the knee.
The same patients reported more flare-ups, in which the knee was hot, painful and swollen for a few days, than other patients did. They also had more instances of excessive fluid in the joint and were more likely to develop other significant health issues. Researchers actually recommended discouraging this type of injection.
When I asked my orthopedic surgeon about viscosupplementation, he cautioned that it might not help me. I faced two knee replacements no surgeon would tackle because of medications for Crohn's disease that intentionally lowered my immunity.
I initially received three injections of Orthovisc in one knee, each a week apart. I had swelling and general discomfort for about 48 hours. However, the improvement, which took several weeks, was dramatic.
I received two more sets of injections in both knees, about six months apart. I noted less improvement after the second set. The third resulted in no detectable improvement. The physician's assistant hit a nerve in two successive weekly injections, and I could hardly walk for about 12 hours. I feel about the same as I did six months ago when I had the last fluid injections for osteoarthritis. It's unlikely I'll sign up for more.
Vonda J. Sines has published thousands of print and online articles. She specializes in health and medical topics, with a special interest in diseases and other conditions that affect quality of life.
- Disease & Medical Conditions
- hyaluronic acid
- synovial fluid