Osteoarthritis (OA) is a type of degenerative joint disease that results from breakdown of joint cartilage and underlying bone. The most common symptoms are joint pain and stiffness. Usually the symptoms progress slowly over years. Initially they may occur only after exercise but can become constant over time. Other symptoms may include joint swelling, decreased range of motion, and, when the back is affected, weakness or numbness of the arms and legs. The most commonly involved joints are the two near the ends of the fingers and the joint at the base of the thumbs; the knee and hip joints; and the joints of the neck and lower back. Joints on one side of the body are often more affected than those on the other. The symptoms can interfere with work and normal daily activities. Unlike some other types of arthritis, only the joints, not internal organs, are affected.
|Other names||Degenerative arthritis, degenerative joint disease, osteoarthrosis|
|The formation of hard knobs at the middle finger joints (known as Bouchard's nodes) and at the farthest joints of the fingers (known as Heberden's nodes) is a common feature of osteoarthritis in the hands.|
|Symptoms||Joint pain, stiffness, joint swelling, decreased range of motion|
|Usual onset||Over years|
|Causes||Connective tissue disease, previous joint injury, abnormal joint or limb development, inherited factors|
|Risk factors||Overweight, legs of different lengths, job with high levels of joint stress|
|Diagnostic method||Based on symptoms, supported by other testing|
|Treatment||Exercise, efforts to decrease joint stress, support groups, pain medications, joint replacement|
|Frequency||237 million / 3.3% (2015)|
Causes include previous joint injury, abnormal joint or limb development, and inherited factors. Risk is greater in those who are overweight, have legs of different lengths, or have jobs that result in high levels of joint stress. Osteoarthritis is believed to be caused by mechanical stress on the joint and low grade inflammatory processes. It develops as cartilage is lost and the underlying bone becomes affected. As pain may make it difficult to exercise, muscle loss may occur. Diagnosis is typically based on signs and symptoms, with medical imaging and other tests used to support or rule out other problems. In contrast to rheumatoid arthritis, in osteoarthritis the joints do not become hot or red.
Treatment includes exercise, decreasing joint stress such as by rest or use of a cane, support groups, and pain medications. Weight loss may help in those who are overweight. Pain medications may include paracetamol (acetaminophen) as well as NSAIDs such as naproxen or ibuprofen. Long-term opioid use is not recommended due to lack of information on benefits as well as risks of addiction and other side effects. Joint replacement surgery may be an option if there is ongoing disability despite other treatments. An artificial joint typically lasts 10 to 15 years.
Osteoarthritis is the most common form of arthritis, affecting about 237 million people or 3.3% of the world's population. It becomes more common as people become older. Among those over 60 years old, about 10% of males and 18% of females are affected. Osteoarthritis is the cause of about 2% of years lived with disability.