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What is a trigger thumb?

When the tendon that moves the tip joint of the thumb becomes locked or catches, it is called a trigger thumb. The tendon that moves the tip joint of the thumb is like a long rope connecting the muscles in the forearm with the bones and joints in the thumb. The tendon runs through a series of tunnels called pulleys. When the tendon is too large, or the tunnel is too small, normal movement of the thumb is prevented and trigger thumb occurs. 

What causes trigger thumb?

Pediatric trigger thumb is thought to be due to a congenital narrowing of the tunnel or pulley at the base of the thumb. Because the tunnel is too small, the tendon that moves the thumb gets stuck and limits normal thumb movement. As children increase the use of their thumb, more symptoms arise, including clicking and catching in the thumb joint, and a fixed, bent position of the thumb. 

Can trigger thumb be treated?

Trigger thumb is treatable. The most common treatment for a locked trigger thumb is a tendon release surgery. Trigger thumbs most often have a thumb stuck in a bent, locked position. If the thumb lacks normal flexibility for at least four to six months, surgical release may be recommended. Some children have symptoms that improve spontaneously during the first four to six months, so your doctor may also recommend observation for a period of time. 

What is a surgical release?

Surgical release is a minor surgical procedure that involves release of the tight tunnel or pulley that is restricting normal movement of the thumb. During the procedure, the thumb is checked to make sure that there is full movement of the tendon. In a child, the surgical release is done under general anesthesia and is a same-day surgery. 

How common is pediatric trigger thumb?

Trigger thumb occurs in about one in 2,000 births. About 10 percent of children who signs of trigger thumb before one year of age; 80 percent show signs between one and three years of age; 10 percent show symptoms at age three or older. About 20 percent of children have trigger thumb in both hands. About 10 percent of children have another family member with trigger thumb.