Trigger Finger

Background

Stenosing tenosynovitis, commonly known as trigger finger, is a condition involving the flexor tendons of the fingers. Each finger has two flexor tendons that glide within a sheath that begins in the palm and ends close to the fingertip. In this condition, the tendons get caught at the A1 pulley which is at the entrance to the sheath in the palm. The result is pain, stiffness, locking and catching during movement of the affected digit. Trigger finger can occur in any finger, as well as the thumb.

Cause

The flexor tendons are involved in bending the fingers into the palm. They travel through a tendon sheath, where they glide freely during finger movement. The tendon sheath is reinforced along its length by several pulleys. Thickening of the sheath or tendons can lead to impaired tendon gliding and increased friction. This condition is often thought to be the result of repetitive use, including forceful flexion, and is increasingly common in patients with diabetes and rheumatoid arthritis, but commonly occurs in healthy patients.

Symptoms

Symptoms include a locking and catching sensation with movement of the fingers, pain when flexing or extending the finger, and occasionally the formation of a nodule at the base of the digit in the palm. In more advanced cases, the affected finger can become permanently locked in a flexed (bent) or extended (straight) position.

Diagnosis & Treatment

The most important diagnostic feature is the physical exam. Usually, no imaging modalities are required. Commonly there is tenderness to touch at the A1 pulley, and occasionally a nodule. The finger can catch with motion, and can even be locked in a flexed or extended position.

An ultrasound can be performed in the office to identify associated ganglion cysts and confirm a buildup of inflammatory tissue (tenosynovitis) as well as thickening of the A1 pulley.

The treatment usually begins with an injection. Alternatively, ice, antiinflammatories (topical or oral) and splinting may be attempted. The injection is usually effective, and can be repeated. The more definitive treatment is surgery, whereby the A1 pulley is released.