Thumbs Up

Dr. Mandl wondered whether an injectible medication called Synvisc, used for knee OA, would work in the thumb.  The active chemical, hyaluronan, also called hyaluronic acid, is present in joint fluid. The ends of joints are capped with cartilage and a piece of cartilage also sits between joints as a cushion.  Hyaluronic acid lubricates the joint, like motor oil, to keep cartilage, gliding in a fluid motion.

Some researchers had already looked at hyaluronan injections for CMC OA, with mixed results.  OA is a difficult disease to study because people have good days and bad days, even without treatment. “Showing a real benefit of medication can be difficult, but it is worth trying to see, in a definitive way, if it might help these patients - because they do not have many options,” says Dr. Mandl.

Currently, the U.S. Food and Drug Administration only approves hyaluronan for the knee. Injections can provide some pain relief for four to six months. The drug is given by local injection. Dr. Mandl found the idea of a local injection appealing for the thumb, especially because some people – people over age 65, in particular - can't tolerate non-steroidal medications, especially if they have gastrointestinal problems such as ulcers.

Patients with CMC OA were divided into three treatment groups. One group received a placebo injection; another group received an injection of corticosteroid, and the third group will receive hyaluronan. Dr. Mandl will follow up at six months to determine whether the patients’ pain is better. The team will also test for any improvement in how well the hand works. At the study’s completion, all participants will have the option of receiving a free injection of hyaluronan.

Her greatest challenge was recruiting patients, which delayed the project at the onset. Patients were more apt to join once Dr. Mandl offered the guaranteed injection once the study is completed. 

Studying hand OA, such as the type of work Dr. Mandl is doing, will help researchers understand the progression of OA in other joints. Studying CMC in a non-weight bearing joint may help researchers identify some of the other risk factors that are not related to weight, such as genetics.

 “We’re going to learn something that will inform practice and that will help us better understand the disease,” says Dr. Katz.