Commonly known as gamer’s thumb or mother’s wrist, De Quervain’s tenosynovitis—also called De Quervain’s syndrome or De Quervain’s disease—is a painful condition that affects the tendons on the thumb side of the wrist. It occurs when tendon entrapment affects the first dorsal compartment of the wrist causing the sheath covering these tendons to become thick and inflamed, making it painful to move the thumb or wrist. De Quervain’s disease, named after Swiss surgeon Fritz de Quervain, affects about 1 percent of the U.
S. population and peaks in people between the ages of 40 and 50. Type I: Characterized by a thickening and tight constriction of the APL and EPB tendons by a loop-shaped retinaculum or connective tissue, with no separation between them.
Type II: The retinaculum compresses only the EPB, leaving a clear separation. The exact cause of dQD isn’t fully understood. It is believed to result from irreversible tissue degeneration, where mucin—a type of protein made of glycosaminoglycans—accumulates within the fibers.
This occurs along with the formation of fibrous tissue deposits and increased blood vessel growth, rather than from acute inflammation of the synovial lining. These changes cause thickening of the tendon sheath on the thumb side of the wrist, which narrows the tunnel through which the tendons slide. As a result, the APL and EPB tendons get trapped, making movement difficult and leading to pain and tendon inflammation, especially during han.