Painful and swollen joints characterize a number of orthopedic injuries and conditions, but in people with inflammatory arthritis, the immediate cause of the swelling and pain is usually inflammation and excessive growth of the synovium, a membrane that lines the joints.
In patients with inflammatory arthritis, excessive growth of synovium is part of an abnormal immune response in which the body recognizes cartilage as a foreign substance that must be attacked. Loss of cartilage eventually leads to damage to the joint surface as well as the stiffness and pain characteristic of all types of arthritis. (Osteoarthritis, the more prevalent form of the disease, does not involve this type of inflammatory response. Other causes, including injury, wear-and-tear, and heredity are thought to contribute to the degeneration of cartilage in osteoarthritis.)
Rheumatologists - physicians who specialize in the treatment of inflammatory arthritis, which includes rheumatoid arthritis, psoriatic arthritis, and juvenile rheumatoid arthritis - usually rely on a variety of medications to control abnormal growth of the synovium. These include both oral drugs known as DMARDs (disease-modifying anti-rheumatic drugs), and in some cases, steroid injections. Patients who don’t respond to these treatments may be referred to an orthopedic surgeon to discuss synovectomy, a procedure in which much of the synovium is removed.