Trigger Finger

What is a trigger finger?

Trigger finger is a common problem that causes pain and snapping of the tendons in the fingers. The problem that occurs in a patient who has trigger finger is due to the tendons of the fingers, and the sheath in which these tendons live.

Finger Tendons

The tendons in your fingers are like ropes that attach to the ends of your fingers. When your forearm muscles contract, the tendons pull the fingers into a fist. The tendons run part of their course through a sheath called the flexor tendon sheath. In patients who have a trigger finger, this mechanism of movement of the tendon within the sheath is not smooth.

Trigger Finger Causes

The cause of trigger finger is often unclear, and 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.

Why is it called a trigger finger?
The name trigger finger is from the symptom of triggering or snapping. This occurs when relaxing a fist, the affected trigger finger remains flexed. When enough force has been gathered, the trigger finger will suddenly extend, like pulling a trigger.
Trigger finger treatments may consist of simple steps, injections, or surgery. Often people start off with something simple, and if the symptoms persist or return, a surgery may be recommended.

Cortisone Injections:

The most common treatment of trigger finger is with an injection of steroids (cortisone) into the tendon sheath. The cortisone often decreases swelling sufficiently to restore normal mechanics. Usually a single cortisone injection will resolve the problem at least temporarily. The chance of the cortisone providing a lasting solution is about 50%.
Side-effects of a cortisone injection are most often minimal, but for some people, they can be quite significant. That is why some doctors and patients choose to skip the shot and move right into more definitive treatment, such as surgery.

Surgery:

Surgery for a trigger finger (called a trigger-finger release) is a same-day procedure that can be done under local anesthetic or regional nerve block. A small (less than two centimeters) incision is made in the skin, and the tight portion of the tendon sheath is released. This allows the tendon to glide smoothly again without catching. Following the trigger-finger release, activity of the finger is encouraged, as this will help prevent scar tissue from forming where the surgery was performed. Patients are advised to avoid pressure on the healing incision for a few weeks. Full recovery is expected.
Trigger finger surgery is very safe, but there are possible complications. The most common problem is that the trigger finger can come back if the tendon sheath is not adequately released. Other possible problems include infection, stiffness and damage to the nerves of the finger. The likelihood of these problems is small, and surgery has a very high success rate.

What Is the Best Option?:

There is not necessarily a best option for trigger finger. There has been some evidence that early treatment with a surgical release can speed overall recovery, as patients tend to have less stiffness and inflammation in the finger. Therefore, some surgeons will recommend more aggressive treatment by skipping over the simple steps and going directly to surgery. However, many patients want to avoid the surgical knife. In those cases, there are very reasonable options that do not include surgery. Discuss with your doctor the best treatment for your situation.