As a hostess in a restaurant and an active person who loved biking, tennis, walking, gardening and traveling, Sally found that her osteoarthritis (OA) had a negative impact on her life. Sally's condition, which affected both knees, made it impossible for her to do most of the activities that she enjoyed. "I couldn't even sleep at night because of the pain in my knees," she recalled.

OA is a degenerative joint disease often found in the hands, knees, hips, feet and spine. It is one of the most common forms of arthritis, affecting more than 40 million Americans, including nearly half of the elderly, and more than a quarter of the population between the ages of 45 and 64. But it also strikes at younger ages. Osteoarthritis occurs when the cartilage that cushions the ends of the bones breaks down, causing bone-on-bone contact and significant pain, loss of movement and deformity.

In addition to the physical limitations imposed by osteoarthritis, OA can also cause financial strain because many patients with this condition can no longer work. Treatments can be expensive. It is estimated that musculoskeletal conditions such as OA cost the U.S. economy more than $86 billion each year in lost wages, production and direct expenses. The emotional toll can also be significant, as patients struggle with loss of ability and feelings of helplessness and depression.

Sally's condition made it impossible for her to walk, especially up and down stairs. The constant pain left her hunched over and limping. No longer able to exercise, she gained weight and her overall health began to deteriorate. It became evident that she needed surgery on both of her knees.

In 2001, Sally underwent total knee replacement surgery on both knees. Today, she is pain-free and able to participate in all the normal activities of daily living. Her husband says she even looks different because the pain is gone. She can now stand up straight, walk, ride a bike and mow the lawn. She exercises four times a week and has lost weight.

As the population continues to age, OA threatens to limit the activities and lives of many more people. New research is seeking knowledge about the causes of OA so that greater preventive measures can be taken. Recent genetic research has linked its cause to mutated collagen genes, providing a promising avenue for future generations to avoid this disabling disease.

Much more research is needed, not only in identifying causes, but also in seeking alternative treatments and in advancing joint replacement techniques. Continued funding for research in osteoarthritis will give others like Sally many more years of mobility and productivity. According to Sally, "people in pain are not leading a good existence and make the world a less happy place."