Dear Liz:

My doctor says I have worn out the cartilage in my knees. What does this mean? Are there any new treatment options to help alleviate knee pain?

Do you realize that the only time in our lives we like to age is when we're kids? Before you're 10, you're so excited about aging that you think in fractions. "How old are you?" "I'm four and a half." Eventually, all that changes. As if you're sour milk, you turn 30. Soon after, you're pushing 40 then reaching 50. By the time you "make it" to 60 you've built up so much speed that ultimately you "hit" 70.

Unfortunately, you're only given one set of knees to get you through all of this turning, pushing, reaching and so on. Your knee's cartilage -- the smooth cushioning tissue that serves as a shock absorber between bones -- wears thin as a result of even normal aging and usage until the surface of your knee becomes rough and bumpy. The result is often stiff, achy, swollen knees that make it difficult to perform basic tasks like walking, kneeling, bending, standing -- activities you take for granted when you and your knees are young. Many people begin to feel the effects of thinning cartilage in their 40s, although it varies depending on your sex, weight, activity level and bone structure.

Doctors typically recommend NSAIDs (non-steroidal anti-inflammatory drugs) such as aspirin and ibuprofen (Aleve, Advil) to help ease knee pain. But those over-the-counter drugs only offer temporary relief. In the most extreme cases of cartilage damage, doctors recommend total knee replacement, a surgical technique that involves leaving the surrounding muscles, tendons and ligaments intact and replacing damaged bone surfaces with an artificial knee joint made of plastic and metal.

Although current knee replacements can last for up to 20 years, they don't offer the same mobility as the knee you were born with. That's where two new and promising treatments, glucosamine sulfate and chondroitin sulfate, may come in. Interestingly, both are supplements taken orally.

• Glucosamine sulfate is naturally produced in very small amounts by your body. Its concentration decreases with age and is found sparingly in individuals with arthritis. This substance plays an important role in forming the cushioning ingredients of joints that is essential for cartilage to function. Adding glucosamine to the diet, some scientists speculate, can help your body repair damaged cartilage.
  
  
• Chrondroitin sulfate acts like "liquid magnets" within the joint and works with glucosamine sulfate to help keep the joint "cushioney." It helps attract the fluid into cartilage, which helps nourish the joint and bolster its shock-absorbing ability; it also protects the cartilage from premature breakdown. Several reliable studies have found that arthritis patients who take glucosamine sulfate in combination with chrondroitin sulfate report a significant reduction in joint pain, tenderness and swelling.

So could the answer to knee pain really be as simple as taking a pill? Possibly. However, these supplements do not yet have FDA approval and are not recommended by either the American College of Rheumatology or the Arthritis Foundation. These agencies and organizations are playing it safe, saying there isn't enough conclusive research to give these drugs the thumbs up. (Both have been used in Europe and in the treatment of race horses for years.)

We at Fit by Friday always recommend consulting your doctor for diagnosis and treatment of knee pain -- or any other medical problem for that matter. We'll keep you posted on any new developments in the treatment of knee pain.

--Michele Bibbey and Liz Neporent

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