Stenosing Tenosynovitis (Trigger Finger) If you wake up in the morning and your thumb or finger is “locked” in a flexed position, you may have a trigger finger. Trigger finger or (Stenosing Tenosynovitis) is inflammation around the tendons to your fingers or thumb. Tendons (cordlike fibers that attach muscle to bone and allow you to bend your fingers) are held in place on the bones by a series of ligaments called pulleys. These pulleys form a series of arches through ...