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Knee Inflammation, Swelling, and Stiffness

The knee serves as a hinge between the thigh and lower leg and also provides some rotation. The largest and one of the most complex joints in the body, the knee supports almost the entire weight of the body. Therefore, when it is affected by RA, it can make mobility difficult or impossible, leading to significant disability.

As is true with RA and joints throughout the body, the sooner diagnosis is made and treatment initiated, the greater the likelihood that joint damage can be minimized or prevented. The availability of disease-modifying anti-rheumatic drugs (DMARDs) and newer biologics that are effective at slowing or preventing structural damage to the joints means that the joints and other structures in the region of the knee can often be preserved and function maintained.


How does RA affect the knee?

Involvement in large joints, such as the knee, including inflammation, swelling, and stiffness (especially in the morning) tends to occur in later stages of RA. Swelling with a build-up of synovial fluid and thickening of the lining of the synovium is particularly common with knee involvement. Both of these effects combine to make movement, particularly flexion (bending), difficult. Due to changes in the joint, ligaments (the fibrous cords that connect bone to bone or cartilage to cartilage and hold the joint together) may become lax. This may lead to the development of deformities and may cause the major muscles of the leg (such as the quadriceps) to atrophy (to waste and become weak). Swelling of the bursa behind the knee joint (called a Baker’s cyst or popliteal cyst) can also occur with RA. In some cases, the cyst may rupture and extend down the calf.1


How is RA-related knee involvement treated?

Treatment of RA symptoms affecting the knee depends on the severity of symptoms and the nature and extent of damage, as well as the patient’s goals and needs. Options include drug and non-drug treatments, and surgery.2

Drug treatments. The initial approach to treatment should involve medications to control inflammation and pain (including analgesics [NSAIDs], disease-modifying anti-rheumatic drugs [DMARDs], and glucocorticoid injection).2

Injection of glucocorticoids directly into the knee may be useful in controlling acute inflammation. However, glucocorticoids will not prevent progression of the disease and structural damage to joints.2

Supplements with glucosamine and chondroitin sulfate, two molecules that are found in cartilage in the joints, may be taken for relief of pain and to reduce joint swelling. Talk to your doctor before you start taking these supplements. They must be taken for two months continuously before they take full effect and are associated with side effects, including headache, nausea, vomiting, and rash.2

Non-drug management approaches. Rest or restriction of activity may be useful in reducing acute pain. Additionally, modifying activities (exercise and certain movements) that cause stress to the knee may also be useful in reducing pain. Application of cold (ice) or heat may also be used to provide relief of acute pain.2

A program of physical therapy or rehabilitation to maintain range of motion, strength, and flexibility may be useful in minimizing pain and preventing further joint damage by strengthening supporting musculature. Water exercises may be particularly useful because they tend to place less stress on the knee.2

Use of supportive devices, including impact-absorbing inserts or shoes, canes, braces, or elastic bands may provide support and stability to improve mobility. Alternative therapeutic techniques, including acupuncture, magnetic pulse therapy, and transcutaneous electrical nerve stimulation (TENS), may also be useful in relieving pain.2

Surgery. If joint symptoms do not respond to medication or other management approaches, surgical interventions may be used. Surgical options include2,3:


Arthroscopic surgery involves making a small incision in the knee and inserting a tube or tubes containing a fiber optic scope and small surgical instruments, which allow the surgeon to remove or repair tissue inside the joint.

In osteotomy, the tibia (shin bone) or femur (thighbone) are cut to correct the alignment of the knee.

Total or partial knee replacement may be used where there is severe damage to the joint and related structures.

Learn more about Knee surgery

Written by: Jonathan Simmons | Last reviewed: September 2013.
1. Maini RN, Venables PJW. Patient information: Rheumatoid arthritis symptoms and diagnosis (beyond the basics). In: O'Dell JR, Greene JM, eds. UptoDate. Wolters Kluwer Health. Accessed at: 2013. 2. Arthritis of the knee. American Academy of Orthopaedic Surgeons. Available at: Accessed on 041613. 3. Clement ND, Breusch SJ, Biant LC. Lower limb joint replacement in rheumatoid arthritis. J Orthop Surg Res 2012;7:7-27.