I am a 68-year-old woman with some pain in my knees when I walk. The doctor told me it is osteoarthritis and that I should take an over-the-counter painkiller and lose weight. Would you please write more about what osteoarthritis is, and what I should do?
Osteoarthritis is the most common form of arthritis, and it occurs in people as they age. Arthritis is inflammation of a joint. The joints are the interfaces of bones, where the bone is covered with a smooth cartilage and encapsulated in a fibrous sac. The lining of the sac is called synovium, and it secretes synovial fluid—a joint lubricant.
In rheumatoid arthritis, the synovium is inflamed because it is targeted by the body’s immune system as though it were foreign tissue. This misguided immune response causes inflammation, and the inflammatory secretions damage the cartilage and joint, leading to deformity. Why the body attacks its own membranes has not been fully clarified.
Other forms of arthritis may be associated with infection, tumors, or even gout. In the latter condition, crystals of uric acid precipitate into the joint and cause inflammation.
Osteoarthritis is not associated with infection, tumors, crystals, or autoantibodies, but seems to occur in people who have a family predisposition, persons who have seriously overworked their joints, or even those who have suffered a trauma. In osteoarthritis, the cartilage over the end of the bone degenerates, for reasons that are not completely clear, and mild to moderate inflammation is set up in the joint. The bone underlying the damaged cartilage becomes increasingly dense, and bony outgrowths at the edges of the joint cause nobby-looking joints.
When this process involves joints such as knees or hips, it can cause difficulty in walking. If it causes small joint arthritis, as in the hands, it results in a loss of dexterity and weakness.
Exercise can be damaging to osteoarthritic joints, but aquatic exercise that is, swimming—has been shown to be very helpful and is the exercise of choice. It also helps to lose weight, especially if the joints involved are knee or hip joints. Dietary changes are not particularly useful in helping osteoarthritis, though a reduced acid load may help rheumatoid arthritis, hence the benefit of a vegetarian diet in that condition.
Some have touted the use of chondroitin sulfate and glucosamine, but a large controlled study sponsored by the National Institutes of Health found them not superior to placebo* (the proverbial “sugar pill”). Limited data support the use of injected hyaluronic acid into the joint, and much of the treatment revolves around pain relief. Acupuncture has been shown to improve the pain in some, but most use acetaminophen (Tylenol). The nonsteroidal antiinflammatories such as Naproxen may be tried in the lowest effective dose in cases in which Tylenol is not helping, but they have side effects on the stomach.
For many, a surgical joint replacement is very helpful, and where we used to delay this as long as possible, some studies suggest earlier replacement may prevent muscle weakness and debility and actually be associated with a more productive lifestyle.
Clearly, this is scanty coverage of this topic, and your doctors will give you more specific advice for your individualized need.
We hope you can obtain sufficient relief so you may enjoy your life.
*Clegg, D. et al., The New England Journal of Medicine, 2006, 354, pp. 794-808.