Hand and Wrist

Trigger Finger

Anatomy

Tendons are tissues that connect muscles to bone. When muscles contract, tendons pull on bones, causing parts of the body to move. Long tendons extend from muscles in the forearm and attach to the small bones of the fingers and thumb. The flexor tendons on the palm side of the hand are used to control the movements of the fingers and thumb. When you bend or straighten your finger, the flexor tendon slides through the tendon sheath, a snug tunnel that keeps the tendon in place next to the bone.

Description

As the flexor tendon slides through the tendon sheath, it can become irritated. If the irritation grows, the tendon may thicken and nodules may form, making passage through the tunnel more difficult. The tendon sheath may also thicken, causing the opening of the tunnel to become smaller. With trigger finger, when you try to straighten your finger, the tendon becomes momentarily stuck at the mouth of the tendon sheath tunnel. As the tendon slips through the tight area, you might feel a pop as your finger suddenly shoots straight out.

Symptoms

Symptoms usually appear without any injury, but often follow a period of heavy hand use. Symptoms may include: a tender lump in your palm, swelling, a catching or popping sensation in finger or thumb joints, and pain when bending or straightening a finger. Stiffness and catching tend to be worse after inactivity, especially in the morning upon awakening. Moving your fingers may help to loosen them up. Occasionally, when the tendon breaks free of the sheath, it can feel like the finger joint is dislocated. One or more fingers may be affected. In severe cases of trigger finger, the finger cannot be straightened, even with help.

Causes

Although the cause of trigger finger is usually unknown, there are factors that indicate an increased risk. Trigger fingers are more common in women than men, occurring most frequently in people between 40 and 60 years of age, sometimes after activities that strain the hand. Trigger fingers are also more common in people with certain medical problems, such as diabetes and rheumatoid arthritis.

Diagnosis

Your physician can diagnose trigger finger by examining your hand and discussing your symptoms with you. X-rays and additional testing are usually not required.

Nonsurgical Treatment

If your symptoms are mild, resting the finger may be enough to resolve the problem. Your doctor may recommend a splint to keep your finger in a neutral, resting position. Over-the-counter pain medications, such as nonsteroidal anti-inflammatory medicines (NSAIDS) or acetaminophen can be used to relieve the pain. Your doctor may choose to inject a corticosteroid into the tendon sheath. Injections may be curative for this disorder in many cases; if temporary relief is obtained from a single injection but the problem recurs, a second injection can be given. If two injections fail to resolve the problem, surgery should be considered. These injections are less likely to provide permanent relief if you have experienced triggering for an extended period of time, or if you have an associated medical problem, such as diabetes.

Surgery

Trigger finger is not a dangerous condition, so your decision to have surgery is based on how severe your symptoms are and whether nonsurgical options have failed. If your finger is stuck in a bent position, your doctor may recommend surgery to prevent permanent stiffness.

• Surgical procedure—The goal of surgery is to widen the opening of the sheath so the tendon can slide through it more easily. The procedure is performed on an outpatient basis, allowing you to return home the same day. After the hand is numbed, usually with an injection of local anesthesia, a small incision will be made in the palm, allowing your orthopaedic surgeon to cut the tendon sheath. Once the sheath has healed, it will be looser, providing more room for the tendon to move through it comfortably.
• Possible complications—If tightness persists beyond the area of tendon sheath that was released, incomplete extension can occur. Incomplete release of the first part of the sheath can result in persistent triggering, or if there is excessive release of the sheath, bowstringing can occur.

Recovery

Most people are able to move their fingers immediately after surgery. Soreness in the palm is common, and you can help reduce swelling and pain by frequently raising your hand above your heart. Recovery is usually complete within a few weeks, but some swelling and stiffness may remain for as long as six months. If your finger was very stiff prior to surgery, you can use physical therapy and finger exercises to help loosen it up.