Trigger Finger

	A trigger finger occurs when the motion of the tendon that opens and closes the finger is limited, causing the finger to lock or catch as the finger is extended.
Trigger finger

Cause

Nodule or thickening in the flexor tendon of the figure. The thicken nodule on the tendon strikes the tunnel, making it difficult to extend the finger.
Courtesy of Griffin LY (ed): Essentials of Musculoskeletal Care. 3rd Ed. Rosemont, IL. American Academy of Orthopaedic Surgeons, 2005

Tendons that control the movements of the fingers and thumb slide through a snug tunnel of tissue created by a series of pulleys that keeps the tendon in place. The tendon can become irritated as it slips through the tunnel. As it becomes more and more irritated, the tendon may thicken, making its passage through the tunnel more difficult. The tissues that hold the tendon in place may thicken, causing the opening of the tunnel to become smaller. As a result, the tendon becomes momentarily stuck at the mouth of the tunnel as the finger is extended. A pop may be felt as the tendon slips past the tight area. This why pain and catching may be felt as the finger is moved.

The cause is not always known. Trigger fingers are more common in women than men. They occur most frequently in people who are between the ages of 40 and 60 years of age. Trigger fingers are more common in people with certain medical problems, such as diabetes and rheumatoid arthritis.

Side (top) and bottom (bottom) views of a finger. The annular pulleys (A1, A2, A3, A4, and A5) keep the tendons close to the bone. The thin, pliable cruciate pulleys (C1, C2, and C3) collapse to allow the finger to bend.

Symptoms
Symptoms of trigger finger usually start without any injury. Symptoms may include the presence of a small lump, pain in the palm, swelling, and a catching or popping sensation in the finger or thumb joints. Stiffness and catching tend to be worse after inactivity, such as when you wake in the morning. Often, finger movement will loosen up with activity. Sometimes, when the tendon breaks free, it may feel like the finger joint is dislocating. In severe cases, the finger cannot be straightened, even with help. Sometimes, one or more fingers are be involved. Patients with diabetes can have several fingers involved, for example.

Diagnosis
Your doctor can diagnose the problem by talking with you and examining your hand. No other testing or X-rays are usually needed to diagnose trigger finger.

Nonsurgical Treatment
If symptoms are mild, resting the finger may be enough to resolve the problem. Over-the-counter pain medications can be used to relieve the pain. Splints are sometimes used to rest the finger.
A physician may choose to inject a corticosteroid. Sometimes, the improvement is temporary and more than one injection may be needed. Injections are less likely to provide permanent relief when the triggering has been present for a long time, or if when there is an associated medical problem like diabetes.

Surgical Treatment
Trigger finger is not a dangerous condition. The decision whether to proceed with surgery is a personal one, based on how severe the symptoms are. If the finger is stuck in a bent position, surgery may be recommended to prevent permanent stiffness.

The goal of surgery is to widen the opening of the tunnel so that the tendon can slide through it more easily. This is usually done on an outpatient basis. The surgery is performed through a small incision in the palm or sometimes with the tip of a needle. Usually, the fingers can be moved immediately after surgery.

Some soreness in the palm is common, but elevating the hand after surgery can help reduce swelling and pain. Recovery is usually complete within a few weeks. If the finger was quite stiff before surgery, therapy may help loosen up the finger.