Arthritis is inflammation of one or more of your joints. Pain, swelling, and stiffness are the primary symptoms of arthritis. Any joint in the body may be affected by the disease, but it is particularly common in the knee.
Knee arthritis can make it hard to do many everyday activities, such as walking or climbing stairs. It is a major cause of lost work time and a serious disability for many people.
The most common types of arthritis are osteoarthritis and rheumatoid arthritis, but there are more than 100 different forms. While arthritis is mainly an adult disease, some forms affect children.
Although there is no cure for arthritis, there are many treatment options available to help manage pain and keep people staying active.
Anatomy
The knee is the largest and strongest joint in your body. It is made up of the lower end of the femur (thighbone), the upper end of the tibia (shinbone), and the patella (kneecap). The ends of the three bones that form the knee joint are covered with articular cartilage, a smooth, slippery substance that protects and cushions the bones as you bend and straighten your knee.
Two wedge-shaped pieces of cartilage called meniscus act as "shock absorbers" between your thighbone and shinbone. They are tough and rubbery to help cushion the joint and keep it stable.
The knee joint is surrounded by a thin lining called the synovial membrane. This membrane releases a fluid that lubricates the cartilage and reduces friction.
Description
The major types of arthritis that affect the knee are osteoarthritis, rheumatoid arthritis, and posttraumatic arthritis.
Osteoarthritis Osteoarthritis is the most common form of arthritis in the knee. It is a degenerative,"wear-and-tear" type of arthritis that occurs most often in people 50 years of age and older, although it may occur in younger people, too.
In osteoarthritis, the cartilage in the knee joint gradually wears away. As the cartilage wears away, it becomes frayed and rough, and the protective space between the bones decreases. This can result in bone rubbing on bone, and produce painful bone spurs.
Osteoarthritis usually develops slowly and the pain it causes worsens over time.
Rheumatoid Arthritis Rheumatoid arthritis is a chronic disease that attacks multiple joints throughout the body, including the knee joint. It is symmetrical, meaning that it usually affects the same joint on both sides of the body.
In rheumatoid arthritis, the synovial membrane that covers the knee joint begins to swell, This results in knee pain and stiffness.
Rheumatoid arthritis is an autoimmune disease. This means that the immune system attacks its own tissues. The immune system damages normal tissue (such as cartilage and ligaments) and softens the bone.Posttraumatic Arthritis
Posttraumatic arthritis is form of arthritis that develops after an injury to the knee. For example, a broken bone may damage the joint surface and lead to arthritis years after the injury. Meniscal tears and ligament injuries can cause instability and additional wear on the knee joint which, over time, can result in arthritis.
Symptoms
A knee joint affected by arthritis may be painful and inflamed. Generally, the pain develops gradually over time, although sudden onset is also possible. There are other symptoms, as well:
The joint may become stiff and swollen, making it difficult to bend and straighten the knee.
Pain and swelling may be worse in the morning, or after sitting or resting.
Vigorous activity may cause pain to flare up.
Loose fragments of cartilage and other tissue can interfere with the smooth motion of joints. The knee may "lock" or "stick" during movement. It may creak, click, snap or make a grinding noise (crepitus).
Pain may cause a feeling of weakness or buckling in the knee.
Many people with arthritis note increased joint pain with changes in the weather.
If you feel knee pain, talk to us. During your visit, we will talk with you about your symptoms and medical history, perform a physical exam, and possibly order diagnostic tests such as x-rays or blood tests.
This article is provided as an informational service and is not a substitute for medical advice.
Anyone seeking specific orthopedic advice or assistance should consult their orthopedic surgeon or schedule an appointment at the Ipiranga Orthopedic Center by clicking here.