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Knee Pain

Knee Rheumatoid Arthritis

Rheumatoid arthritis, or RA, is an autoimmune and inflammatory disease, which means that your immune system attacks healthy cells in your body by mistake, causing inflammation (painful swelling) in the affected parts of the body.

RA mainly attacks the joints, usually many joints at once. RA commonly affects joints in the hands, wrists, and knees. In a joint with RA, the lining of the joint becomes inflamed, causing damage to joint tissue. This tissue damage can cause long-lasting or chronic pain, unsteadiness (lack of balance), and deformity (misshapenness).

RA can also affect other tissues throughout the body and cause problems in organs such as the lungs, heart, and eyes.

​In rheumatoid arthritis (RA) of the knees, the immune system mistakenly attacks the tissue that line the knee joints, causing pain, inflammation, and swelling. It can severely affect a person’s mobility.


RA is the result of an immune response in which the body’s immune system attacks its own healthy cells.  The specific causes of RA are unknown, but some factors can increase the risk of developing the disease.

Researchers have studied a number of genetic and environmental factors to determine if they change person’s risk of developing RA.

Characteristics that increase risk

  • Age. RA can begin at any age, but the likelihood increases with age. The onset of RA is highest among adults in their sixties.

  • Sex. New cases of RA are typically two-to-three times higher in women than men.

  • Genetics/inherited traits. People born with specific genes are more likely to develop RA. These genes, called HLA (human leukocyte antigen) class II genotypes, can also make your arthritis worse. The risk of RA may be highest when people with these genes are exposed to environmental factors like smoking or when a person is obese.

  • Smoking. Multiple studies show that cigarette smoking increases a person’s risk of developing RA and can make the disease worse.

  • History of live births. Women who have never given birth may be at greater risk of developing RA.

  • Early Life Exposures. Some early life exposures may increase risk of developing RA in adulthood.  For example, one study found that children whose mothers smoked had double the risk of developing RA as adults. Children of lower income parents are at increased risk of developing RA as adults.

  • Obesity. Being obese can increase the risk of developing RA. Studies examining the role of obesity also found that the more overweight a person was, the higher his or her risk of developing RA became.


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.


When you see your doctor, you’ll get a physical exam and talk about your personal and family medical histories. You may also get blood tests to help see if you have RA. Those check for:

  • Anemia (low red blood cell count)

  • Rheumatoid factor (RF), found in about 70% to 80% of people with RA

  • “Sed” rate (erythrocyte sedimentation rate). High levels are a sign of inflammation.

  • Antibodies to a chemical called CCP

  • High levels of CRP (C-reactive protein)

You may also get an X-ray or, less frequently, an MRI to check on possible joint damage. And your doctor may take a sample of your synovial fluid, which comes from your joints.

Non-surgical treatments

OA can't be cured, but therapies are available to ease symptoms and to slow down the degeneration. Recent information shows that mild cases of knee OA may be maintained and in some cases improved without surgery.

  • Taking pain relievers: Your healthcare provider may recommend taking pain relievers (non-steroidal anti-inflammatory medications, or NSAIDs) to help reduce pain and swelling in your knee. Acetaminophen can be used as an alternative if you cannot tolerate NSAIDs or are allergic.

  • Glucosamine and chondroitin sulfate: These supplements seem to have nearly the same benefits as anti-inflammatory medicine with fewer side affects. Many doctors feel the research supports these supplements and are encouraging their patients to use them.

  • Cortison injection: Cortisone is a powerful anti-inflammatory medication, but it has secondary effects that limit its usefulness in the treatment of OA. Multiple injections of cortisone may actually speed up the process of degeneration. Repeated injections also increase the risk of developing a knee joint infection, called septic arthritis. Any time a joint is entered with a needle, there is the possibility of an infection. Most physicians use cortisone sparingly, and avoid multiple injections unless the joint is already in the end stages of degeneration, and the next step is an artificial knee replacement.

  • Hyaluronic acid injection: Doctors inject three to five doses into the joint over a one-month period. The medicine helps lubricate the joint, ease pain, and improve people's ability to get back to some of the activities they enjoy. These injections are less effective for older adults and severe OA.

  • Physical therapy: You will learn ways to calm pain and symptoms, which might include the use of rest, heat, or topical rubs. You will also be taught how to protect the arthritic knee joint by modifying your activities. Range-of-motion and stretching exercises will be used to improve knee motion.

  • Walking aids: This may include shock-absorbing insoles, a cane or walker, a knee unloading brace, or a heel wedge