Arthritis of the knee is a condition that causes inflammation, pain, swelling and limited movement of the knee joint and connective tissues around the knee. Joints are places where two bones meet, such as your elbow or knee. Over time, a swollen joint can become severely damaged. Arthritis is one of over 100 types of rheumatic diseases or diseases that affect joints and connective tissues. The word “arthritis” literally means inflammation of a joint (from the Greek “arthro” for joint and “itis” for inflammation). Depending on the type of knee arthritis, symptoms can range from pain and swelling in the joints to difficulty using or moving the joint in a normal way.
Arthritis of the knee is a condition in which there is loss of the articular cartilage of the femur, tibia, or patella. This can be seen on x-ray as a loss of the space between the two ends of bone. Because of the loss of the gliding surfaces of the bone, people with arthritis may feel as though their knee is stiff and their motion is limited. Sometimes people actually feel a catching or clicking within the knee. Generally, loading the knee joint with activities such as walking long distances, standing for long periods of time, or climbing stairs makes arthritis pain worse. When the arthritis has gotten to be severe, the pain may occur even when sitting or lying down. The pain is usually felt in the inside part of the knee, but also may be felt in the front or back of the knee. As the cartilage is worn away preferentially on one side of the knee joint, people may find their knee will become more knock-kneed or bow-legged.
Knee arthritis affects approximately 16 million people, typically who are over the age 50 years. It is most common in people who are overweight and the disease can often be managed with weight loss. Knee arthritis may be caused by trauma to the knee, such as a torn meniscus. There are also those who are genetically predisposed to knee arthritis.
If you feel pain and stiffness in your knee or have trouble moving it around, you might have arthritis. Most kinds of arthritis cause pain and swelling in your joints.