Page 14 - Imaging of Osteoarthritis and Rheumatoid Arthritis in Hand Joints
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                                Chapter 1
the hand affected mostly are the wrists, metacarpal (MCP) joints and proximal interphalangeal (PIP) joints, and the disease occurs also in metatarsophalangeal (MTP) joints, shoulders, elbows, knees and ankles. An immune reaction created by the body targets the joint synovium, starting synovitis.7 This inflammation results in hypertrophy and neovascularization of the synovium, and production of excess synovial fluid. The inflammation then spreads to the adjacent bone and to the joint cartilage, ultimately resulting in bone and cartilage destruction (see fig. 1). Clinically, the affected joints usually become swollen, painful, and stiff in the morning. Over time, the cartilage and bone destruction results in deformity and further loss of function. The disease is not limited to the musculoskeletal system; RA patients also have increased risk of cardiovascular disease, and the disease affects lungs, brain, skin and liver, which are thought to be caused by byproducts of the inflammatory reaction.7 While there is no treatment to cure the disease, available disease-modifying antirheumatic drugs (DMARDS) can slow or stop the progression of RA, improving symptoms and preventing joint deformity. Diagnosing RA is relatively easy in late stage disease. However, the goal is to treat RA as early as possible, to prevent this stage. In the early stage it is often difficult to diagnose RA, as typical clinical signs and symptoms may be absent and specific laboratory tests may be normal.
Figure 1. Schematic anatomical differences between a normal hand joint, a joint with osteoarthritis and a joint with rheumatoid arthritis. Note that there is cartilage loss and loss of joint space in both disease, but mainly proliferation of bone on the joint edges in osteoarthritis and destruction of bone in rheumatoid arthritis (Image duplicated from the Mayo foundation with permission).

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