We hear a lot about hip and knee joint replacements. But smaller joints can be replaced, too. Surgery to replace joints in the fingers is most common with rheumatoid arthritis (RA). The metacarpophalangeal (MCP) joint is affected most often. The MCPs form the large knuckles on the back of the hand. The MCPs stick out when the hand is in a fist.
RA is a chronic inflammatory disease. It affects many organs and systems in the body, especially the musculoskeletal system. The lining of the joints becomes inflamed. Cartilage starts to soften, and joint damage occurs. Change in one joint affects how all the other joints in the hand line up. The soft tissues around the joints are affected, too. This sets up a vicious cycle.
Without normal muscle pull, increased and uneven forces cause still more damage and deformity. Ligaments stretch and weaken. The fingers and wrist start to drift away from their normal middle position. Painful deformity, joint dislocation, and joint destruction can lead to the need for joint replacement. This operation is not advised if a patient has certain skin conditions, poor bone condition, or vasculitis (inflammation of the blood vessels).
The authors of this report review the anatomy of the finger joints and discuss the technique for MCP joint replacement. Results after surgery are also reviewed. With MCP implants, patients can expect better hand position and pain relief. Sometimes the fingers start to drift from the midline again. Most patients are happy with the results of the new joint because the hand looks and feels better.