Knee Arthritis Injections Battle It Out

Feb. 20, 2002 -- A study presented at a meeting of orthopedic specialists shows that Synvisc knee injections provide longer and better relief than anti-inflammatory steroids injections. And a second study shows that Synvisc may work as well or better than anti-inflammatory pills.

Synvisc is a fluid made from a substance called hyaluronan that is found in normal joint fluid. Hyaluronan acts as a shock absorber and lubricates your knee joint. Synvisc treatment -- for osteoarthritis, or degenerative arthritis, of the knee -- consists of three injections given one week apart. Generally, Synvisc is most effective about eight to 12 weeks after the injections.

Lead researcher William Linwood Lanzer, MD, compared the effects of the three weekly Synvisc knee injections to one injection with an anti-inflammatory steroid drug called Aristospan. The researchers studied 220 people with osteoarthritis of the knee. Lanzer, who is a clinical associate professor at the University of Washington, received funding from Synvisc's maker Wyeth-Ayerst.

Synvisc was twice as effective at relieving pain from knee osteoarthritis -- even six months after the injections.

Those treated with Synvisc had an average improvement of 30%. But the steroid injection group only had a 17% improvement six months down the road.

In a second study looking at Synvisc, researchers compared the injections to anti-inflammatory drugs, such as ibuprofen and naproxen. This study is published in the Feb. 11 issue of the Archives of Internal Medicine.

The 120 people with knee osteoarthritis were divided into four groups. Group 1 received both Synvisc injections and the anti-inflammatory drug Arthrotec; group 2 got Synvisc injections with a placebo that looked like Arthotec; group 3got Arthrotec with placebo injections; and group 4 got only a placebo.

After four weeks, lead researcher Robert John Petrella, MD, PhD, and colleagues found that Synvisc seemed to be as effective as Arthotec in relieving pain at rest and disability. In addition, the injections seemed to be better than the pill in relieving pain with activity and improving ability to function normally.

Synvisc doesn't work for everyone and studies are still underway to determine exactly how well the drug works. Some doctors are convinced of its usefulness -- others are not. These two studies suggest that Synvisc injections are potentially a very useful treatment for knee osteoarthritis. You and your doctor can decide together if these injections may be right for you.