"Trigger finger" is the common name for stenosing tenosynovitis, a condition affecting the tendons and pulleys in the hand that are used to bend the fingers.
Inside the hand, tendons act like ropes that connect the muscles in the forearm with the bones of the fingers and thumb. The tendons in the finger run through a tunnel made up of a series of rings or pulleys, which holds the tendons close to the bone. To ease the tendon's movement, the tunnel has a slippery lining.
If the pulley where the finger joins the hand thickens and tightens around the tendon so it can't move freely, trigger finger or trigger thumb results. The tendon can sometimes grow a knot or nodule, or its lining can swell, and because it no longer glides easily through the pulley, it can produce pain or a popping sensation when the digit is moved.
Such a triggering sensation isn't like any other feeling. The tendon will worsen over time in a vicious cycle of swelling, inflammation, and triggering. Whenever it catches, it swells and inflames more extensively. If left untreated, the finger or thumb can become stiff and difficult to move or bend.
The causes of trigger finger are not well known, but there appears to be some relationship to diabetes, gout, or rheumatoid arthritis. Trigger finger may present itself if the palm or the base of the finger or thumb receives a traumatic event, but most cases have no known cause.
The first symptom may be a feeling of discomfort or tenderness where the finger or thumb meets the palm, sometimes with a small bump or nodule. As the condition develops and the finger or thumb starts to lock or trigger, it is often associated with the middle finger knuckle or the one closest to the tip of the thumb.
Your hand surgeon will effectively eliminate the catching or locking that restricts movement of the finger or thumb so that it can move freely once again. To accomplish this, any swelling in the tendon or tunnel must be reduced so that the tendon can move freely through the tunnel.
A splint may be used to restrict movement, or anti-inflammatory medications may be prescribed. To further reduce the swelling, some activities may have to be changed. Often, injecting steroids into the area relieves the condition.
If none of these conservative treatments are successful, one of our hand surgeons may recommend surgery, which can be performed with local anesthesia on an outpatient basis. Your hand surgeon will try to open up the pulley where the tendon is sticking, located where the thumb or finger meets the palm. Immediately following the procedure, the finger or thumb will once again be used actively. Once it's comfortable to do so, normal use of the hand can return.
Following surgery, some patients may experience longer periods of swelling, discomfort, and tenderness. Hand therapy might be suggested as a way to get better use of the hand.