The Basics of Osteoarthritis
Arthritis is a general term that means inflammation of the joints. Osteoarthritis, commonly known as wear and tear arthritis, is the most common type of arthritis. It is associated with a breakdown of cartilage in joints and can occur in almost any joint in the body. It commonly occurs in the weight bearing joints of the hips, knees, and spine. It also affects the fingers, thumb, neck, and large toe. Osteoarthritis -- also called OA -- usually does not affect other joints unless previous injury or excessive stress is involved.
Cartilage is a firm, rubbery material that covers the ends of bones in normal joints. Its main function is to reduce friction in the joints and serve as a "shock absorber." The shock-absorbing quality of normal cartilage comes from its ability to change shape when compressed (flattened or pressed together).
Osteoarthritis causes the cartilage in a joint to become stiff and lose its elasticity, making it more susceptible to damage. Over time, the cartilage may wear away in some areas, greatly decreasing its ability to act as a shock absorber. As the cartilage deteriorates, tendons and ligaments stretch, causing pain. If the condition worsens, the bones could rub against each other.
Who Gets Osteoarthritis?
Osteoarthritis affects an estimated 27 million Americans. The chance of developing the disease increases with age. Most people over age 60 have osteoarthritis to some degree, but its severity varies. Even people in their 20s and 30s can get osteoarthritis. In people over 50, more women than men have osteoarthritis.
Symptoms of osteoarthritis most often develop gradually and include:
Joint aching and soreness, especially with movement
Pain after overuse or after long periods of inactivity
Stiffness after periods of rest
Bony enlargements in the middle and end joints of the fingers (which may or may not be painful)
What Causes Osteoarthritis?
There are several factors that increase a person's chances of developing osteoarthritis. These include:
Heredity. Some people have an inherited defect in one of the genes responsible for making cartilage. This causes defective cartilage, which leads to more rapid deterioration of joints. People born with joint abnormalities are more likely to develop osteoarthritis, and those born with an abnormality of the spine (such as scoliosis or curvature of the spine) are more likely to develop osteoarthritis of the spine.
Obesity. Obesity increases the risk for osteoarthritis of the knee, hip, and spine. Maintaining ideal weight or losing excess weight may help prevent osteoarthritis of these areas or decrease the rate of progression once osteoarthritis is established.
Injury. Injuries contribute to the development of osteoarthritis. For example, athletes who have knee-related injuries may be at higher risk of developing osteoarthritis of the knee. In addition, people who have had a severe back injury may be predisposed to develop osteoarthritis of the spine. People who have had a broken bone near a joint are prone to develop osteoarthritis in that joint.
Joint overuse. Overuse of certain joints increases the risk of developing osteoarthritis. For example, people in jobs requiring repeated bending of the knee are at increased risk for developing osteoarthritis of the knee.
Other diseases. People with rheumatoid arthritis, the second most common type of arthritis, are more likely to develop osteoarthritis as well. In addition, certain rare conditions, such as iron overload or excess growth hormone, increase the chance of developing OA.
How Is Osteoarthritis Diagnosed?
The diagnosis of osteoarthritis is based on a combination of the following factors:
Your description of symptoms
The location and pattern of pain
Your doctor may use X-rays to help confirm the diagnosis and make sure you don't have another type of arthritis. X-rays show how much joint damage has occurred. An MRI may be necessary to get a better look at the joint and surrounding tissues if the X-ray results do not clearly point to arthritis or another condition.
Sometimes blood tests will be given to determine if you have a different type of arthritis.
If fluid has accumulated in the joints, your doctor may remove some of the fluid (called joint aspiration) for examination under a microscope to rule out other diseases.
How Is Osteoarthritis Treated?
Osteoarthritis usually is treated by a combination of treatments, including exercise, weight loss if needed, medications, physical therapy with muscle strengthening exercises, hot and cold compresses to the painful joint, removal of joint fluid, injection of medications into the joint, and use of supportive devices such as crutches or canes. Surgery may be helpful to relieve pain when other treatment options have not been effective.
The type of treatment will depend on several factors including your age, activities and occupation, overall health, medical history, location of your osteoarthritis, and severity of the condition.