Trigger Thumb is an inflammation of the tendon(s) that flex or bend the thumb(s). The tendons act as cords that pull the fingers down into a fist and then relax as the extensor tendons on the back of the hand straighten the fingers. Think of the tendon as a line on a fishing rod and the pulleys as the eyelets that keep the line in contact with the rod as it bends and straightens. A knot in the line may make the line catch as it is pulled through the eyelet. If the knot keeps getting larger or the pulley gets tighter, eventually it will be too large to slide back in the other direction and the line will be stuck. That is what happens to the tendons. They simply get too large to move back and forth through the pulleys.
Causes of trigger thumb can be rheumatoid arthritis, gout, diabetes or a trauma to the base of the thumb, but more often than not, the cause is unknown.
Symptoms of Trigger Thumb
- A “popping” pain when bending or straightening the end of the thumb
- Thumb sticks in a bent position and in severe cases has to be pulled straight
- Tenderness when pressure is applied over the base of the thumb
Trigger Thumb is an inflammatory process. The earlier treatment is started, the better chance that the triggering can be relieved with conservative treatment.
Intermittent icing and a proper dosage of anti-inflammatory medicines are important and should be started as soon as possible. If the problem is severe and has progressed to the point where the tendon locks the thumb in a bent position, a steroid injection to reduce the inflammation may be required. If the problem persists, surgery may be recommended to loosen the tendon sheath (covering) and restore motion.
Splinting is important to limit the range of motion of the thumb in order to allow the tendon to rest. A splint that limits motion allows the tendon to rest. What is most important with Trigger Thumb is to prevent the tendon from moving to the point where it snaps or clicks. This can be accomplished with a finger-based splint, such as an Oval-8 Finger Splint. Please view our video “How to treat a Trigger Finger with an Oval-8 Finger Splint” for more information.
It is important to wear the splint until the symptoms are completely gone. Continuing to use a splint at night after an injection or surgery can be very helpful as a “retainer” to prevent clenching the thumb into a fist at night. Visit Oh My Arthritis to purchase an Oval-8.