Osteoarthritis (OA) refers to a type of arthritis where there is wear and tear degeneration of the articular cartilage. Articular cartilage is the smooth lining that covers the ends of bones where they meet to form the joint. The cartilage gives the knee joint freedom of movement by decreasing friction.
The articular cartilage is kept slippery by joint fluid made by the joint lining (the synovial membrane). The fluid, called synovial fluid, is contained in a soft tissue enclosure around synovial joints called the joint capsule.
During the process of degenerative osteoarthritis the articular cartilage wears away, then the bone underneath is uncovered and rubs against bone. Small outgrowths called bone spurs may form in the joint.
Nonsurgical treatment of knee osteoarthritis focuses on reducing pain and improving joint function. It is common to be prescribed acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) to relieve pain and swelling in arthritic patients.
Unfortunately these drugs have side effects that can lead to poor healing and internal bleeding.
In recent years, two unique natural compounds have been used by people with knee OA. Glucosamine and chondroitin sulfate are dietary supplements usually taken in pill form that are thought to protect and possibly help repair cartilage cells.
Glucosamine and chondroitin sulfate occur naturally in the body, mainly in joint cartilage. The theory is that supplementing the two of them can help protect, or possibly even repair, damaged cartilage.
Glucosamine and chondroitin sulfate also help fight inflammation, which in turn reduces joint pain, swelling and tenderness from knee OA. These compounds seem to work in a different way than NSAIDs. They take longer to achieve the same benefit, but the results tend to last longer than NSAIDs. Most importantly, they have fewer side effects than NSAIDs.
Glucosamine and chondroitin sulfate are somewhat controversial treatments. While some studies have supported their effectiveness in relieving the symptoms of knee OA, the research still leaves many unanswered questions, especially about long-term effects. But two problems remain. First, there has not been enough long-range research to determine whether their use is practical. Second, because dietary supplement manufacture is not regulated, product quality (especially of chondroitin products) is not assured.
Though the data isn’t conclusive, these two supplements have been shown to decrease pain and improve joint mobility in patients with knee OA. Most people start to notice a difference after taking the supplements for four weeks. Maximum benefits happen by eight to 12 weeks, and the benefits seem to last even after treatment has ended.
Like any medication or supplement, it seems some people respond to a greater degree than others. If you haven’t noticed change after eight weeks in your symptoms, then glucosamine and chondroitin sulfate are probably not for you.
Realise that taking care of knee OA involves many possible treatments. Glucosamine and chondroitin sulfate are not magic bullets. They are aspects of a comprehensive treatment plan. Managing knee OA works best using a variety of proven strategies.
Patients do best when they also:
- Perform aerobic exercise;
- Do strengthening and range of motion exercises;
- Lose weight (when appropriate);
- Use heat and cold packs;
- Use orthotics (foot supports) when appropriate.
By decreasing pain and increasing joint movement, glucosamine and chondroitin sulfate may help patients maximise their ability to take care of their knee OA.