De Quervain’s tendinosis occurs when the tendons around the base of the thumb are irritated or constricted. The word “tendinosis” refers to a swelling of the tendons. Swelling of the tendons, and the tendon sheath, can cause pain and tenderness along the thumb side of the wrist. This is particularly noticeable when forming a fist, grasping or gripping something, or when turning the wrist.
Two of the main tendons to the thumb pass through a tunnel (or series of pulleys) located on the thumb side of the wrist. Tendons are rope-like structures that attach muscle to bone. Tendons are covered by a slippery thin soft-tissue layer, called synovium. This layer allows the tendons to slide easily through a fibrous tunnel called a sheath.
Any swelling of the tendons and/or thickening of the sheath, results in increased friction and pain with certain thumb and wrist movements.V
De Quervain’s tendinosis may be caused by overuse. It also is associated with pregnancy and rheumatoid disease. It is most common in middle-aged women
Signs of De Quervain’s tendinosis:
To determine whether or not you have De Quervain’s tendinosis, your physician may ask you to perform the Finkelstein test by placing your thumb against your hand, making a fist with your fingers closed over your thumb, and then bending your wrist toward your little finger.
If you have De Quervain’s tendinosis, this test is quite painful, causing tendon pain on the thumb side of the wrist.