Caused by a breakdown of cartilage, this condition is the most common form of arthritis, usually affecting the hands, feet, spine and weight-bearing joints hips and knees.
By: Dr. Leon Costa
Osteoarthritis (OA) is a type of arthritis that is caused by a breakdown of cartilage, the protein substance that provides a necessary cushion between the bones and joints. OA, the most common form of more than a hundred different types of arthritis, is one of the leading causes of disability for Americans, affecting more than 15 million people nationwide, the majority of them over the age of 50.
Mostly related to aging, osteoarthritis usually affects the hands, feet, spine and large, weight-bearing joints, such as the hips and knees. As the body ages, the joints are subject to repetitive use and can become irritated and inflamed. Eventually, the cartilage begins to degenerate, and tiny crevasses are formed. This loss of cushioning causes friction between the bones, creating pain and limiting joint mobility.
In addition to primary OA, some conditions can lead to secondary OA, such as obesity, repeated trauma or surgery to the joint structures, congenital joint abnormalities, diabetes, gout and other hormone disorders. Although OA is a condition found in older patients, it is sometimes traced back to childhood. If someone sustains even one severe or significant knee injury, that person is four times as likely to develop OA over the next 20-30 years.
|
‘According to the Centers for Disease Control and Prevention, the incidence of osteoarthritis of the knee is expected to rise to 57 percent by 2020, as America’s population ages.’ Dr. Leon Costa
Orthopedic surgeon The Medical Center at Princeton |
Symptoms vary greatly, with the most common being joint pain. The affected joints can feel warm, swell, creak and usually feel worse later in the day or after lengthy inactive periods. In severe cases of OA where there is complete loss of cartilage cushion, pain is often felt even with limited motion and at rest.
When diagnosing OA, X-rays of the affected joints can prove helpful. It is common for X-rays to reveal a loss of joint cartilage, narrowing of the joint space between adjacent bones and bone spur formation. In addition, blood tests are performed to exclude diseases that can cause secondary osteoarthritis and other arthritis conditions that can mimic osteoarthritis.
Arthrocentesis, in which a needle is used to extract joint fluid for analysis, is often performed. Like the blood test, this allows doctors to rule out gout, infection and other causes of arthritis. An injection of corticosteroids into the joints during arthrocentesis can relieve pain, swelling and inflammation.
Finally, no exam would be complete without a careful analysis of the joint symptoms, including their location, duration and character. Spur formations, which appear as bony enlargement of the joints, are characteristic of osteoarthritis and are best seen on X-rays.
OA leads to changes in the natural substance that helps provide the joints with lubrication and shock absorption. This joint fluid is called synovial fluid and has been the subject of much study in recent years, particularly when dealing with OA of the knee. Researchers have developed an injectable fluid, available as Synvisc, that is derived from chicken combs and can be injected into the knee with few side effects. It attempts to reproduce the elasticity and shock absorption that is comparable to the synovial fluid of healthy 20-somethings, producing long-term pain reduction and improved mobility.
This treatment, known as viscosupplementation, involves three injections given at one-week intervals. The fluid is absorbed and incorporated into the lining of the joint within several days. Usually, patients feel improvement after several weeks, although some feel better immediately. The continuing improvement maximizes at six to eight weeks as the inflammation decreases and the irritation fades.
Studies find that the average improvement after viscosupplementation is nine months. Many patients find it lasts longer, sometimes as long as two to three years. The series of injections can be repeated, and if the patient is finding that the injections are not providing lasting improvement, then it is most likely time to consider joint replacement.
It is important to realize that this treatment is not exclusive, but works best when combined with physical therapy and occupational therapy, as well as rest, weight reduction and mechanical support devices. Medications such as acetaminophen and nonsteroidal agents may be taken orally, or cortisone may be injected into the joints to decrease joint inflammation and pain.
According to the Centers for Disease Control and Prevention, the incidence of osteoarthritis of the knee is expected to rise to 57 percent by 2020 as America’s population ages. The advent of a new drug-free therapy for joint pain is an exciting breakthrough and gives doctors and patients much to crow about.
Dr. Leon Costa is a board-certified orthopedic surgeon on staff at The Medical Center at Princeton. This article was prepared in collaboration with Lorraine Seabrook. Health Matters appears Fridays in the Lifestyle section of The Princeton Packet and is contributed by The Medical Center at Princeton.