Osteoarthritis, or OA, is the most common form of arthritis. This chronic disease affects about 80% of Canadians by the time they reach the age of 75. In the U.S. nearly 21 million people over the age of 45 have OA. It has been estimated that 41 million Americans 65 years and over will have OA by the year 2030.
OA is a non inflammatory disease of the joints that results in a breakdown of cartilage over time. You’ve already learned that cartilage cushions the end of the bones and acts as a shock absorber. In a healthy person, cartilage breaks down and then restores itself. In the person with OA, cartilage breaks down much faster than it can be repaired. When cartilage is gone, bone surfaces grate together causing pain. Pain is also felt in the muscles and supporting tissues. Bony spurs grow from the bone edges, leading to changes in the shape of the bone and joint, and synovial fluid increases.
WHAT ARE THE RISK FACTORS FOR OA?
The exact cause of OA is not known. Several factors, however, called “risk factors”, make it more likely that someone will get OA. These factors include:
80% of people over the age of 65 have some degree of OA that can be seen on an x-ray. As the number of older adults increase, we can expect that OA will become more common over time.
Obese persons are at increased risk for OA, mainly OA of the knees. Standing or walking exerts a pressure of up to 6 times a person’s body weight on the knees and up to 3 times the body weight on the hips. So you can see why obesity can lead to joint problems.
OA is not thought to be a genetic disease, although there is an increased risk for those whose parents had the disease.
Injury or trauma
An example would be an injury caused by lifting over a period of time.
Lack of exercise
Regular exercise lowers the risk of OA in several ways. It helps strengthen supporting muscles, tendons and ligaments, it promotes cartilage growth and it assists in weight control.
READ MORE: Caring for Someone With Arthritis
WHAT ARE THE SYMPTOMS OF OA?
OA can be present for many years before symptoms appear. The first symptom of OA is often the slow onset of aching joint pain. OA most often affects joints in the knees, hips, spine, ankles, and hands. Pain often occurs with activity and is relieved by rest. Joint stiffness occurs after periods of inactivity. Stiffness improves as the person moves around.
There is no one test for OA. The diagnosis is based upon the following:
The history includes the symptoms. There may be local pain and stiffness with little or no swelling. The affected joints are usually weight-bearing ones as well as joints in the spine and in the hand. The pain may occur with activity but improve with rest.
Some joints may be enlarged. Limited range of motion may be present. Crepitus is a grating sound
and sensation caused by bones rubbing together. It may be heard and felt upon movement of one or more affected joints. Advanced disease may cause some joints to “lock” as the person walks. The disease can also result in bony growths in the hands.
X-rays may show bony spurs and a narrowed joint space due to wearing away of cartilage.
A lab test can be done to rule out other types of arthritis such as RA and gout.
TREATMENT FOR OA
There is no cure for OA. The disease, however, can be managed. Below are some steps for managing OA:
This is helpful if the person is obese. Excess weight causes stress on weight-bearing joints such as the hips and knees.
Exercise allows synovial fluid to warm and thin out. This makes it easier for cartilage in the joint to absorb the fluid. As the cartilage absorbs fluid, it swells and acts as a better cushion against friction. Exercise allows cartilage to do its job. Only through exercise can cartilage get rid of waste products and do the job it is supposed to do. More than one kind of exercise may be helpful. Flexibility exercises help keep the joints from becoming stiff. Strengthening exercises help maintain or increase strength. Low-impact aerobic exercises such as walking, swimming, water aerobics and stationary biking, have many benefits. Aerobic exercise helps maintain a healthy weight, improve overall fitness, and reduce pain. It also promotes strength and flexibility.
Before starting any exercise program, it is important to consult a physician to ensure the best plan for the person with arthritis.
• Acetaminophen is often used to treat OA. Tylenol is a common form of acetaminophen. It is used for pain relief but does not reduce inflammation. Acetaminophen should be taken only as directed. Overdosing can result in liver damage.
• Non steroidal anti-inflammatory drugs (NSAIDs) help reduce stiffness, pain and swelling of the joints. Long-term use at high dosages, however, has been linked to possibly serious side effects. These side effects include internal bleeding, high blood pressure and heart and kidney problems. Vioxx, one of the most widely used NSAIDs, was freely withdrawn from the worldwide market by Merck & Co. Inc. in 2004. The decision to withdraw
Vioxx was based upon findings from a drug trial that showed an increased risk of heart attack and stroke after 18 months. People taking NSAIDs should be encouraged to learn about the possible side effects and to report any that are present to their doctor.
• Stronger pain relief meds (e.g. long-acting opoids) are sometimes ordered for severe pain.
• A topical pain reliever works to reduce pain. The cream is rubbed into the skin over a joint. It is often used to help control pain in the knees and hands.
• Steroids are sometimes injected into acutely inflamed joints. The process should be done no more than four times in a one-year period.
Glucosamine and chrondoitin
This is a nutritional supplement that is widely used to treat the symptoms of OA. Further research is needed to find out how well the product works.
Heat or cold therapy
Some people find that applying heat (e.g. hot shower) helps reduce joint pain. Cold treatments to a joint may help decrease the swelling and pain.
This is sometimes needed to restore joint motion when the disease has extremely limited joint function. Surgery may involve cleaning or removing damaged tissue or realigning or fusing joints. Fusing involves joining two bones together. Replacement surgery involves removal of part or all of the damaged bone and replacing it with artificial products. Total hip replacement (THR) and total knee replacement (TKR) are two common types of surgery done to restore joint function. If you are caring for a loved one following surgery, such as a THR or TKR, be sure to follow his or her post-op treatment plan.
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