Osteoarthritis is a joint disease that mostly affects cartilage. Cartilage is the slippery tissue that covers the ends of bones in a joint. Healthy cartilage allows bones to glide over each other. It also helps absorb shock of movement. In osteoarthritis, the top layer of cartilage breaks down and wears away. This allows bones under the cartilage to rub together. The rubbing causes pain, swelling, and loss of motion of the joint. Over time, the joint may lose its normal shape. Also, bone spurs may grow on the edges of the joint. Bits of bone or cartilage can break off and float inside the joint space, which causes more pain and damage.
People with osteoarthritis often have joint pain and reduced motion. Unlike some other forms of arthritis, osteoarthritis affects only joints and not internal organs. Rheumatoid arthritis — the second most common form of arthritis — affects other parts of the body besides the joints. Osteoarthritis is the most common type of arthritis.
Osteoarthritis usually happens gradually over time. Some risk factors that might lead to it include:
- Being overweight
- Getting older
- Joint injury
- Joints that are not properly formed
- A genetic defect in joint cartilage
- Stresses on the joints from certain jobs and playing sports.
Osteoarthritis symptoms often develop slowly and worsen over time. Signs and symptoms of osteoarthritis include:
- Pain. Your joint may hurt during or after movement.
- Tenderness. Your joint may feel tender when you apply light pressure to it.
- Stiffness. Joint stiffness may be most noticeable when you wake up in the morning or after a period of inactivity.
- Loss of flexibility. You may not be able to move your joint through its full range of motion.
- Grating sensation. You may hear or feel a grating sensation when you use the joint.
- Bone spurs. These extra bits of bone, which feel like hard lumps, may form around the affected joint.
When to see a doctor
If you have swelling or stiffness in your joints that lasts for more than a few weeks, make an appointment with your doctor.
During the physical exam, your doctor will closely examine your affected joint, checking for tenderness, swelling or redness. He or she will also check the joint's range of motion. Your doctor may also recommend imaging and lab tests.
- X-rays. Cartilage doesn't show up on X-ray images, but the loss of cartilage is revealed by a narrowing of the space between the bones in your joint. An X-ray may also show bone spurs around a joint. Many people have X-ray evidence of osteoarthritis before they experience any symptoms.
- Magnetic resonance imaging (MRI). MRI uses radio waves and a strong magnetic field to produce detailed images of bone and soft tissues, including bone cartilage. This can be helpful in determining what exactly is causing your pain.
- Blood tests. Blood tests may help rule out other causes of joint pain, such as rheumatoid arthritis.
- Joint fluid analysis. Your doctor may use a needle to draw fluid out of the affected joint. Examining and testing the fluid from your joint can determine if there's inflammation and if your pain is caused by gout or an infection.
There's no known cure for osteoarthritis, but treatments can help to reduce pain and maintain joint movement.
- Acetaminophen. Acetaminophen (Tylenol, others) can relieve pain, but doesn't reduce inflammation. It has been shown to be effective for people with osteoarthritis who have mild to moderate pain. Taking more than the recommended dosage of acetaminophen can cause liver damage.
- Nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDs reduce inflammation and relieve pain. Over-the-counter NSAIDs include ibuprofen (Advil, Motrin, others) and naproxen (Aleve, others). Stronger NSAIDs are available by prescription. NSAIDs can cause stomach upset, ringing in your ears, cardiovascular problems, bleeding problems, and liver and kidney damage. Older people are at highest risk of complications.
- Narcotics. These types of prescription medication typically contain ingredients similar to codeine and may provide relief from more severe osteoarthritis pain. These stronger medications carry a risk of dependence, though that risk is thought to be small in people who have severe pain. Side effects may include nausea, constipation and sleepiness.
- Work with a physical therapist. Ask your doctor for a referral to a physical therapist. The physical therapist can work with you to create an individualized exercise regimen that will strengthen the muscles around your joint, increase the range of motion in your joint and reduce your pain.
- Find ways to avoid stressing your joints. Find ways to go about your day without stressing your joints. An occupational therapist can help you discover ways to do everyday tasks or do your job without putting extra stress on your already painful joint. For instance, a toothbrush with a large grip could make brushing your teeth easier if you have finger osteoarthritis. A bench in your shower could help relieve the pain of standing if you have knee osteoarthritis.
- Try braces or shoe inserts. Consider trying splints, braces, shoe inserts or other medical devices that can help reduce your pain. These devices can immobilize or support your joint to help you keep pressure off it.
- Take a chronic pain class. The Arthritis Foundation and some medical centers have classes for people with osteoarthritis or chronic pain. Ask your doctor about classes in your area or check with the Arthritis Foundation. These classes teach skills that help you manage your osteoarthritis pain. And you'll meet other people with osteoarthritis and learn their tips and tricks for reducing and coping with joint pain.
Surgical and other procedures
- Cortisone shots. Injections of corticosteroid medications may relieve pain in your joint. During this procedure your doctor numbs the area around your joint, and then inserts a needle into the space within your joint and injects medication. The number of cortisone shots you can receive each year is limited, because the medication can cause joint damage.
- Lubrication injections. Injections of hyaluronic acid derivatives (Hyalgan, Synvisc) may offer pain relief by providing some cushioning in your knee. These treatments are made of rooster combs and are similar to a component normally found in your joint fluid.
- Realigning bones. During a surgical procedure called an osteotomy, the surgeon cuts across the bone either above or below the knee to realign the leg. Osteotomy can reduce knee pain by shifting your body weight away from the worn-out part of your knee.
- Joint replacement. In joint replacement surgery (arthroplasty), your surgeon removes your damaged joint surfaces and replaces them with plastic and metal devices called prostheses. The hip and knee joints are the most commonly replaced joints. Surgical risks include infections and blood clots. Artificial joints can wear out or come loose and may need to eventually be replaced.
Every person with OA is different. Pain and stiffness may prevent one person from performing simple daily activities, while others are able to maintain an active lifestyle that includes sports and other activities.
Your movement may become very limited over time. Doing everyday activities, such as personal hygiene, household chores, or cooking may become a challenge. Treatment usually improves function.
- Reactions to drugs used for treatment
- Decreased ability to perform everyday activities, such as personal hygiene, household chores, or cooking
- Decreased ability to walk