DRG Category: 546

Mean LOS: 5.3 days

Description MEDICAL: Connective Tissue Disorders with CC

classification section:



Rheumatoid arthritis (RA) is a chronic, progressive, systemic disease characterized by recurrent inflammation of connective tissue, primarily diarthrodial joints (hinged joints that contain a cavity within the capsule that separates the bony elements to allow freedom of movement) and their related structures. RA affects approximately 2% of all adults.

The disease generally begins with inflammation of the synovial membrane, which becomes thickened and edematous. The thickened synovium, or pannus, erodes the articular cartilage and underlying bone, causing joint destruction. The small peripheral joints of the hand and wrist and the joints of the knees, ankles, elbows, and shoulders are usually affected symmetrically. The cervical spine may also be affected. Extra-articular involvement of the disease includes inflammation of the tendon sheaths; the bursae; and the connective tissue of the heart, lungs, pleurae, and arteries.

If the disease is left untreated, the inflammatory process of RA moves through four stages. In the first stage, synovitis is caused by congestion and edema of the synovial membrane and joint capsule. In the second stage, the formation of pannus, thickened layers of granulation tissue that cover and invade cartilage begins, and this leads to eventual destruction of the joint capsule and bone. In the third stage, fibrous ankylosis is noted in the inflammatory process; this is the fibrous invasion of the pannus and scar formation that occludes joint space. In the fourth and final stage, the fibrous tissue calcifies, causing ankylosis and total immobility.

Complications caused by RA include temporomandibular joint disease, which impairs the patient's chewing and causes headaches. Infection, osteoporosis, myositis, cardiopulmonary lesions, lymphadenopathy, and peripheral neuritis may also occur.