Itís the most common arthritis in the world. Some say that 80% of humanity will suffer from osteoarthritis (OA) at sometime in their lives. Perhaps because of that ubiquity, itís acquired the name ďdegenerative arthritis,Ē implying that as people age, itís an inevitable problem.
That implication is probably not the case, however. Think of it this way: wrinkles are a part of aging, so is graying of hair. Just about everyone develops those signs of advancing years. But not everyone develops OA. Enough people do, however, to make it appear that this joint problem is a degenerative process that comes with age.
But in clinical practice, the illness can start at the age of about thirty, though the majority of sufferers are in their forties to seventies. Inflammation is the problem, but unlike other types of inflammatory arthritis (rheumatoid or psoriatic), in OA the inflammation starts in the cartilage that covers the surface of the bones and acts kind of like human Teflonģ.
It allows the bones to move smoothly over one another. When the cartilage is inflamed, the result is pain as we put pressure on cartilage which is inflamed and rough.
Cartilage is about 70% water. The rest is made up of long-chain sulfated carbohydrates which are interlinked to form a matrix very similar to gelatin. Imagine if you poured three packets of Jell-O into a bowl and added a small amount of water. Youíd get a very stiff gelatin, almost hard to the touch. Youíve basically just made a bowlful of cartilage.
When that stiff cartilage gets inflamed, white blood cells invade the gel structure and release enzymes that digest the long-chain carbohydrate molecules. The matrix gets broken down. The support for the cartilage thus is damaged and the cartilage itself gets worn away as you move the joint.
The joint begins to narrow, and sometimes ends up with the underlying bones touching one another. Not only does that limit how far you can move the joint, but it can cause a lot of pain. Bone spurs grow at the joint margins that can press into surrounding muscles to cause more pain. Muscles overlying OA joints also can get sore because of the underlying inflammation and cause pain as they go into spasm.
Where is the problem most commonly? The most common site for osteoarthritis is in the hips, knees, spine, and some joints of the hands. The shoulders are sometimes involved as well.
In the hips and knees, damage can be so bad that doctors suggest joint replacement surgery. In the spine, bone spurs can press inward on spinal nerves and produce spinal stenosis, a condition with symptoms of aching leg pain on walking that is relieved by stopping to rest. In the hands, the thumb bases and the middle and last knuckles of the fingers are typical sites, and knobby growths from bone spurs can cause disfigurement there.
Though there is a lot of research going on in OA, no one knows what causes it. We can manage the problem in lots of different ways. The first is physical therapy to strengthen muscles around the joints so they become better shock absorbers.
Also, unlike many types of arthritis, itís best to use OA joints because the movement squeezes the cartilage. Cartilage has no blood supply, so this squeezing pushes nutrients into it and washes out the enzymes that are breaking down the cartilage and causing the trouble.
Most of the time, though the joints are painful, they donít become swollen. Occasionally, an OA joint can swell and go through an acute flare. When is happens in an easily accessible joint like a finger or knee, an injection of cortisone often is all thatís needed to calm it down.
Non-steroid anti-inflammatory drugs (NSAIDís) are another means of therapy. The most common are over-the-counter Ibuprofen and Naproxen, commonly sold as Advil and Aleve, respectively. Other NSAIDís are available by prescription. Taken daily or in high doses, they can cause stomach ulcers and kidney damage. Acetaminophen, sold as Tylenol and Patanol, is a good pain-killer but doesnít reduce inflammation.
Itís said that the NSAIDís may slow the process of OA, but the regular use of these agents can result in the stomach and kidney problems noted above.
Supplements? Thereís glucosamine sulfate and chondroitin sulfate, made from crustacean shells and beef cartilage. Though there have been some allergic reactions to these agents, theyíre generally safe and can be found over-the-counter in drug stores and vitamin shops. The National Institutes of Health in Washington recently published a study finding that the two agents in combination may relieve the pain of OA in the knee more than OA in other locations. However, many clinicians have found that the supplements are effective for pain in other OA-involved joints. It may even be true that these supplements slow down the disease process, but that has not been proved.
Hyaluronic acid is the main component of joint fluid which serves to lubricate the joint. In OA, this lubrication may dry up to some degree. Recently, a number of synthetic hyaluronic acid products have hit the market, including Synvisc and Hyalgan. Several injection of these drugs directly into OA joints not only lubricate the joints, but for some unknown reasons to date, they actually relieve pain for up to ten months. The injections should be done by someone who follows patients with OA on a regular basis, especially a rheumatologist.
As noted above, when nothing else can be done for a painful joint, especially the hip or knee, joint replacement surgery can often be the solution. These joints are made with modern-day materials such as ceramic or titanium. Though they used to be held in place by resin cements, more modern prosthetic joints are held tightly by the bodyís own bony tissue and often last for the lifetime of the patient.