DEAR DOCTOR K:
I have a painful trigger finger on my left hand. What caused it, and what can I do about it?
The term “trigger finger” may conjure up visions of sharpshooters and hunters — people who sometimes are too quick to draw their guns. To doctors, however, “trigger finger” refers to a condition that occurs when the finger briefly locks and then suddenly releases as you try to bend or straighten it. This often causes a snapping sound.
Perhaps surprisingly, our fingers contain no muscles. Rather, muscles in the hand control our fingers. Those muscles are attached to tendons, which, in turn, are attached to our finger bones. Different muscles and tendons pull on the finger bones, causing the fingers to move.
Trigger finger affects the tendons. A tendon is like a small rope of tough fibers. In a healthy finger, tendons glide smoothly through a tunnel. Like the tendon, the tunnel is formed of tough fibers attached to a finger bone. That tunnel keeps the tendon close against the bone.
Sometimes the tendon develops a knot (nodule). Other times the lining covering the tendon swells, narrowing the space through which the tendon passes. In either case, the tendon no longer glides smoothly through the tunnel. The result is pain and a catching feeling. When the tendon catches, the tunnel can become (more) swollen and irritated, creating a vicious cycle. Sometimes the tendon becomes completely stuck in the tunnel, and the finger can’t be straightened or bent. Here is an illustration showing what happens in trigger finger :
An often-painful condition, trigger finger is caused by a narrowing of the sheath that surrounds the tendon and irritation of the pulley in the affected finger. Trigger finger is most common in people over age 40 who also have rheumatoid arthritis. Symptoms include a sensation of “catching” when trying to bend or straighten the finger. A bump (nodule) may also form.
People who are older than 40 and who have rheumatoid arthritis, gout or diabetes seem to be more prone to the problem.
There are several things you can try to break the cycle of inflammation and pain. These include wearing a splint or taking anti-inflammatory drugs such as ibuprofen or naproxen. Your doctor can inject a steroid in the area around the tendon, reducing the inflammation and swelling of the tunnel.
If your symptoms don’t improve, surgery is an option. A quick and simple procedure allows the tendon to glide through more easily. Usually, this restores finger movement right away. You may feel tenderness, swelling and discomfort for one month or longer. Full recovery can take several months to a year.
A patient of mine, a man in his 60s, developed a trigger finger. Since he was a writer and spent a lot of time at a keyboard, he had a problem. He joked: “I don’t get an idea that often. When I get one, I need to type it quickly, before I lose it.” Simple measures didn’t solve the problem, but simple surgery did.
A few months later he came to the office for a follow-up visit. When I asked him how his typing was, he said: “I’ve got a terrible problem. Now I have no trouble typing. That means that on a day I don’t write much, I’ve got no excuse.”