As with most treatments for osteoarthritis, Synvisc® (hylan G-F 20) can cause side effects. During clinical trials, the most common side effect of Synvisc was knee pain or swelling, which occurred in up to 7.2 percent of people. In most cases, this problem is mild and can be treated with pain relievers, if necessary. More severe cases may require the joint to be drained or steroid injections into the joint. Because knee pain and swelling may be signs of serious problems (such as an infection), be sure to report such problems immediately to your healthcare provider.
Besides side effects, there are other potential dangers with Synvisc to be aware of before starting treatment. You should not use this particular product if you are allergic to any ingredients used to make it, including chicken products (such as feathers or eggs), since Synvisc is made from chicken combs. It is important to know that Synvisc should never be injected into the bloodstream or anywhere else except the knee joint.
(Click Synvisc Side Effects and Synvisc Warnings and Precautions for a more complete list of potential Synvisc dangers and to find out what other side effects may occur with this arthritis treatment.)