Trigger finger or trigger thumb is an inflammatory condition that causes pain, stiffness, and a sensation of locking or catching when you bend and straighten your finger. The condition is also known as “stenosing tenosynovitis.”

The ring finger and thumb are most often affected by trigger finger, but it can occur in the other fingers, as well.

The Anatomy

The flexor tendons, which flex the fingers and thumb, run on the palm side of the hand in a tunnel called the flexor tendon sheath. Within this tunnel, there are fibrous bands, called pulleys, which run across the top of the flexor tendon and pull it down. For each of our fingers, there is a tight area where the flexor tendon sheath is somewhat constrictive, called the A1 pulley. This is located on the palm side of the knuckles. 

Any condition that produces inflammation or swelling of the flexor tendons may produce a localized area of swelling on the flexor tendon (known as nodular flexor tenosynovitis). The swollen area of the tendon to the thumb or finger may then become restricted by the A1 pulley, producing a catching, clicking or actual locking of the thumb or finger. This is similar to a rope with a knot on it getting caught at the pulley.

The Causes

Overuse activities, such as repetitive gripping, may produce a swelling of the flexor tendons and a trigger thumb/finger. 

Inflammatory disorders such as rheumatoid arthritis, lupus or gout, can produce a trigger thumb/finger. 

Trauma to the hand may cause bleeding in the flexor tendon sheath is a risk factor that can lead to this condition. 

Finally, recent surgery in the hands/palm – such as carpal tunnel surgery – may also produce swelling and a trigger finger/Palm.

The Treatment

Conservative treatment consists of an injection with Xylocaine and Cortisone in the flexor tendon sheath surrounding the tendon, followed by a series of flexor tendon gliding exercises designed to help promote free gliding of the flexor tendons in the flexor tendon sheath. 

When conservative treatment fail, or if there is repeated recurrence of a trigger thumb/finger, surgery is the next step in treatment. 

Surgery consists of a trigger thumb or trigger finger release. This is an outpatient procedure with local standby or twilight anesthesia. After administering local anesthesia, a small transverse incision is made on the palm over the A1 pulley of the affected digit. The A1 pulley is released and cut, and the swollen tenosynovium or tissue around the tendon may be trimmed back. The skin is then closed. 

A small dressing is applied post-op. Early finger motion is encouraged immediately as part of recovery. The patient may use the hand for simple activities such as eating or getting dressed. However, there is no heavy lifting or carrying allowed for two weeks after surgery. 

The patient is required to keep the dressing and incision dry for two weeks. After two weeks, the sutures are removed and the patient may resume most normal activities. 

Possible complications include anesthesia-related problems, wound healing problems, or infection.