Ask the Doctors October 2003 Issue

Ask Dr. Marks: 10/03

I have severe osteoarthritis of the knee but I'd rather avoid a total knee replacement if I can. I have heard about hyaluronic acid injections. Do they work and will they work for me?

Hyaluronic acid injections consist of highly purified sodium hyaluronate that comes from rooster combs. Hyaluronate is a natural chemical that is found in high concentrations in the fluid that fills the joint. It has been used since 1987 in Europe, South America, and Asia as a treatment for osteoarthritis. More recently, it has been used in the United States for the same purpose. Even with this long experience, its use is still controversial.

Studies indicate that patients report a significant improvement in their symptoms following injection of hyaluronic acid. This improvement lasts for as long as six months. It is unclear, however, whether this is a placebo effect or actual effect. A study performed at the University of Washington showed no difference in effect between hyaluronic acid injections and injection of cortical steroid into the knee. There were differences in how the medication was delivered and the cost of the treatment. Hyaluronic acid requires injection of the substance three to five times. This can be repeated in six months’ time. A cortisone injection requires only one injection. Cortisone injections can be repeated in three months’ time. Hyaluronic acid has limited use in the treatment of osteoarthritis. It should be used only after other proven treatments such as pain relievers, NSAIDs and corticosteroid joint injections have been tried.


My doctor has suggested that I have developed rheumatoid arthritis because it is in my genes. But no one in my past or immediate family has ever had arthritis. Is there any connection?

The gene HLA-DRW4 has been linked to rheumatoid arthritis. It is present only in a small number of individuals and can be tested for by a genetic test. In clinical situations, this test is not widely used. It is believed that genetics plays only a minor role in rheumatoid arthritis. If no one in your family has a history of rheumatoid arthritis, genetic predisposition has probably not played a significant role in your case.


I'm planning an extensive overseas trip. Should I take a doctor's note? Do I need copies of my prescriptions? How should I adjust my dosage schedule when traveling across different time zones? What about drugs that need refrigeration?

It is always a good idea to take a list of your medications, including the generic names of your medications, when you are on a trip. Also, a brief summary of your medical diagnosis can be very helpful to a foreign doctor. You do not need to take copies of your prescriptions since your doctor’s prescription will not be legal in foreign countries. When traveling across different time zones, arthritis medications can be taken at their regular time; dosing schedules need not be altered in different time zones when taking arthritic medications. None of the oral medications you take with you need refrigeration. If you have questions about a specific medication, you should consult with your doctor before leaving. Also take with you your doctor's name, telephone number, and e-mail address so that he may be consulted if the need arises.