Three basic types of arthritis may affect the knee joint.

Three basic types of arthritis may affect the knee joint.

Causes

• Osteoarthritis (OA) is the most common form of knee arthritis. OA is usually a progressive degenerative disease in which the joint cartilage gradually wears away. It most often affects middle-aged and older people.
• Rheumatoid arthritis (RA) is an inflammatory type of arthritis that can destroy the joint cartilage. RA can occur at any age. RA generally affects both knees.
• Post-traumatic arthritis can develop after an injury to the knee. This type of arthritis is similar to osteoarthritis and may develop years after a fracture, ligament injury or meniscus tear.

Symptoms
Generally, the pain associated with arthritis develops gradually, although sudden onset is also possible. The joint may become stiff and swollen, making it difficult to bend or straighten the knee. Pain and swelling are worse in the morning or after a period of inactivity. Pain may also increase after activities such as walking, stair climbing or kneeling. The pain may often cause a feeling of weakness in the knee, resulting in a "locking" or "buckling." Many people report that changes in the weather also affect the degree of pain from arthritis.

Treatment
In its early stages, treament of arthritis of the knee focuses on conservative, nonsurgical measures. Lifestyle modifications may be recommended, including losing weight, switching from running or jumping exercises to swimming or cycling, and minimizing activities such as climbing stairs that aggravate the condition. A program of special exercises can help increase range of motion and flexibility as well as help strengthen the muscles in the leg. Using supportive devices such as a cane, wearing energy-absorbing shoes or inserts, or wearing a brace or knee sleeve also can be helpful. Other measures may include applications of heat or ice, water exercises, liniments or elastic bandages.

Several types of drugs can be used in treating arthritis of the knee. Because every patient is different, and because not all people respond in the same way to medications, your orthopedic surgeon will develop a program for your specific condition. He may suggest
anti-inflammatory medications such as aspirin, acetaminophen or ibuprofen to help reduce swelling in the joint; Glucosamine and chondroitin sulfate supplements to relieve the pain; and Corticosteroids, which are inflammatory agents that can be injected into the joint. Hyaluronate therapy consists of a series of injections designed to change the character of the joint fluid. Special medical treatments for RA include gold salt injections and other disease-modifying drugs.

If your arthritis does not respond to these nonoperative treatments, you may need surgery.