Glucosamine and Chondroitin Sulfate for Osteoarthritis of the Knee
Physiotherapy in Calgary for Knee Issues
Welcome to Momentum Health's guide to Glucosamine and Chondroitin Sulfate for Osteoarthritis of the Knee
Nonsurgical treatment of knee osteoarthritis (OA) focuses on reducing pain and maintaining or improving joint function. Doctors commonly prescribe acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) to relieve pain and swelling in arthritic patients. Newer NSAIDs called COX-2 inhibitors are showing promise as well.
In recent years, people with knee OA have also been taking two unique compounds. These compounds are gaining greater acceptance among many doctors. 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 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.
This guide will help you understand:
What part of the knee joint does OA affect?
The main problem in knee OA is 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.
An important substance present in articular cartilage and synovial fluid is called hyaluronic acid. Hyaluronic acid helps joints collect and hold water, improving lubrication and reducing friction. It also acts by allowing cells to move and work within the joint.
Related Document: Momentum Health's Guide to Knee Anatomy
What do doctors hope to achieve with these compounds?
Glucosamine and chondroitin sulfate occur naturally in the body, mainly in joint cartilage. These substances can also be synthetically made and given in pill form or by injection. The theory is that these supplements can help protect, or possibly even repair, damaged cartilage. Scientific studies lend support to the benefits that these supplements have on reducing pain, swelling, and tenderness, along with improving knee joint mobility.
Laboratory experiments suggest the synovial fluid absorbs glucosamine that is introduced to the body from an external source. Glucosamine supplements also seem to encourage production of hyaluronic acid. Doctors think that normal hyaluronic acid levels in the knee joint keep the cartilage healthy and suppress pain in patients with knee OA.
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. It's possible that some patients may get good pain relief with a combination of the two.
Though the data isn't conclusive, these two supplements have been shown to decrease pain and improve joint mobility in patients with knee OA. In a recent study, knee pain from OA was found to decrease mostly in those people suffering from moderate to severe pain, but not those suffering with just mild pain. 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. It is usually recommended that glucosamine and chondroitin sulfate can be taken indefinitely as long as one feels that there is relief from symptoms in their affected joints. Long term use (longer than 3 months), however, should be discussed with your doctor to ensure it is safe in each individual case. Studies to support the effectiveness and safe long term use of these supplements are ongoing.
How will I prepare for treatment?
It is best to prepare for this treatment by talking to your doctor and gathering any information regarding these supplements for yourself. Organizations in your area that deal with arthritis can be useful (i.e. the Arthritis Foundation of your country.) Not all forms of arthritis respond to these supplements and taking care of knee OA can involve many possible treatments including treatment with physiotherapy. Glucosamine and chondroitin sulfate are not magic bullets. They are one form of treatment in a comprehensive approach to knee OA.
Related Document: Momentum Health's Guide to Osteoarthritis
Procedure and Complications
How are these treatments administered?
Doctors commonly prescribe oral glucosamine in doses of 500 milligrams three times per day or 1,000 milligrams twice per day. A patient may get a quicker response with a higher dosage. Obese patients may require higher dosages. Most studies of chondroitin sulfate use a dosage of 1,200 milligrams daily.
What might go wrong?
One potential benefit beyond pain relief for both glucosamine and chondroitin sulfate seems to be that patients experience fewer side effects with these drugs than with NSAIDs.
Most people can take these supplements without complications. Some people, however, complain of gastrointestinal problems, which clear up when patients stop taking the supplement. Although rare, negative reactions may include nausea and vomiting, headache, painful digestion, softened or loose stool, abdominal pain, heartburn, throbbing or fluttering of the heart, skin reaction, edema (swelling), and discomfort in the legs.
What happens after treatment?
Many patients report ongoing benefits, even after they stop taking these supplements. Past studies have shown that the ability of these compounds to fight inflammation may be slower to take effect than NSAIDs yet the benefits seem to outlast NSAIDs. Until further studies are completed it cannot be said that there is proof to show that these supplements rebuild damaged cartilage. Given the possible protection to the cartilage, however, some doctors have their patients use these supplements in hopes of maintaining joint health.
Although glucosamine and chondroitin sulfate appear to have a useful place in treating knee OA, it is not recommended they be used alone without any other concurrent treatment. Managing knee OA works best when combined with physiotherapy and lifestyle changes, such as weight loss, and increasing your overall physical fitness.
Your physiotherapist will encourage weight loss through both dietary changes as well as strength training, and cardiovascular activities such as walking (if tolerable), stationary or ordinary cycling, or pool activities such as swimming or water aerobics. The pool is a particularly good venue to partake in cardiovascular activities for weight loss as well as perform many of the exercises your physiotherapist prescribes for range of motion and strengthening. The water naturally takes some of the pressure off of your joint and therefore many patients with OA find the water particularly therapeutic especially if the water is warmer than usual public pool temperature.
The final part of our treatment will include exercises for your balance. As the result of any injury or pain the receptors in your joints and ligaments that assist with balance and proprioception (the ability to know where your body is without looking at it) decline in function. This is true with OA knees as well. Your physiotherapist at Momentum Health will prescribe exercises for you to regain and maintain this balance and proprioception. This might include exercises such as standing on one foot or balancing with both feet on an unstable surface such as a pillow or a soft plastic disc. Depending on the stage of your OA and your ability, your physiotherapist may even prescribe agility exercises such as gentle hopping or moving side to side.
Fortunately, most patients with knee OA who combine the use of glucosamine and chondroitin sulfate with our rehabilitation program at Momentum Health feel that their pain decreases, they are better able to manage their symptoms, and are also able to improve their activity level and quality of life. If, however, your knee does not respond as we would expect to the treatment we provide at Momentum Health, we will promptly liaise with your doctor regarding the best management plan to assist you.
Momentum Health provides services for physiotherapy in Calgary.
Portions of this document copyright MMG, LLC.