Trigger Finger

In the normal hand, the flexor tendons pass through the palm and enter the flexor sheath, a tight series of pulleys extending through the fingers. This sheath provides support and helps maintain the position of the tendons in relation to the bones. This relationship helps to maximize efficiency of joint motion in response to muscle and tendon function. The space between the tendons and the sheath is narrow, and lined with fluid to help gliding with minimal friction.

Inflammation can occur along the tendon entrance site into the sheath from many causes, including trauma and repetitive stressful pinching and grasping. In addition, conditions such as diabetes and rheumatoid arthritis frequently cause such inflammation. As a result, the tendon may become thickened and the first annular (A1) pulley can tighten, causing a size discrepancy that leads to catching as the tendon passes by this point.

Patients experience a "triggering" motion in the proximal interphalangeal joint (the second from the fingertip) in the fingers or the interphalangeal joint (the closest to the tip) in the thumb. Usually the joint can be flexed (bent) easily, but then becomes caught as extension (straightening) is attempted. A tender lump is also frequently felt in the area of the inflammation. The triggering usually causes pain in the palm, but may also involve the abnormally moving joint. As a result, the problem may be confused with arthritic conditions of the joint.

Untreated trigger fingers can lead to joint stiffness and permanent loss of motion over time. Tendon rupture is uncommon in most people, but can occur in patients with rheumatoid arthritis due to the inflammatory "tenosynovitis" that can invade the tendon.

Treatment for trigger finger is focused on correcting the width discrepancy between the tendon and sheath, either by reducing the inflammation or surgically releasing the sheath. Anti-inflammatory medications, splinting, and hand therapy modalities can be helpful. Steroid injection is very helpful, resolving the triggering in 60% of patients after one injection and nearly 20% more following a second injection. Surgery is very effective, with cure rates higher than 95%. Surgery is done as an outpatient, usually through local anesthesia, and involves a small incision over the palm and division of the A1 pulley to reestablish smooth gliding. Resolution of triggering is immediate.

Education regarding trigger finger remains important to prevent delayed diagnosis of a condition that can be successfully treated in most cases.

Go To Page: 1 2