Trigger Finger
Trigger finger is a condition in which one of your fingers or your thumb catches in a bent position. Your finger or thumb may straighten with a snap — like a trigger being pulled and released. If trigger finger is severe, your finger may become locked in a bent position.
Trigger finger involves the pulleys and tendons in the hand that bend the fingers. The tendons work like long ropes connecting the muscles of the forearm with the bones of the fingers and thumb.
In the finger, the pulleys are a series of rings that form a tunnel through which the tendons must glide, much like the guides on a fishing rod through which the line (or tendon) must pass. These pulleys hold the tendons close against the bone. The tendons and the tunnel have a slick lining that allows easy gliding of the tendon through the pulleys (see image to right).
Trigger finger/thumb occurs when the pulley at the base of the finger becomes too thick and constricting around the tendon, making it hard for the tendon to move freely through the pulley. Sometimes the tendon develops a nodule (knot) or swelling of its lining.
Because of the increased resistance to the gliding of the tendon through the pulley, one may feel pain, popping, or a catching feeling in the finger or thumb (see image to right).
Symptoms of Trigger Finger
Trigger finger/thumb may start with discomfort felt at the base of the finger or thumb, where they join the palm. It more commonly occurs in the dominant hand and most often affects your thumb, middle or ring finger. Triggering is usually worse in the morning. A “bump”may sometimes be found in this area.
What causes Trigger Finger?
While the cause is unclear, Trigger Finger can seemingly appear from nowhere. It can occur in one or more fingers, and can occur at different times in different locations. Trigger Finger results from a discrepancy between the size of the tendon and the entrance to the tendon sheath. This discrepancy can be the result of localized inflammation or a nodular swelling on the tendon itself.
When the size discrepancy between the tendon and the tendon sheath reaches a critical point, the tendon will experience resistance from the tendon sheath.
At first, this is experienced as a snapping of the trigger finger when relaxing a fist. If the condition worsens, the trigger finger may need active force from other fingers to straighten, or may not straighten at all.
Treatment Options
The goal of treatment in trigger finger/thumb is to eliminate the catching or locking and allow full movement of the finger or thumb without discomfort. Swelling around the flexor tendon and tendon sheath must be reduced to allow smooth gliding of the tendon. The wearing of a splint or taking an oral anti-inflammatory medication may sometimes help. Treatment may also include changing activities to reduce swelling. An injection of steroid into the area around the tendon and pulley is often effective in relieving the trigger finger/thumb.
If non-surgical forms of treatment do not relieve the symptoms, surgery may be recommended. This surgery is performed as an outpatient, usually with simple local anesthesia. The goal of surgery is to open the pulley at the base of the finger so that the tendon can glide more freely. Active motion of the finger generally begins immediately after surgery. Normal use of the hand can usually be resumed once comfort permits. Some patients may feel tenderness, discomfort, and swelling about the area of their surgery longer than others. Occasionally, hand therapy is required after surgery to regain better use.
Click here to learn more about Endoscopic Cubital Tunnel Release.
