Trigger Finger

Trigger finger is a common condition where a finger

triggers or locks in a flexed position. The finger may have to be straightened manually with the other hand when it locks down. This is usually very painful. Any of the fingers and the thumb can be involved in triggering.

A trigger finger is commonly seen and frequently in association with osteoarthritis. The pathology starts with thickening of the inside of a pulley that acts as a tunnel for the tendon as it runs closely to the bone. When the inner wall of the tunnel becomes thickened, there is less space available for the tendon and its surrounding sheath to glide freely. When it becomes more constrictive, the tendon with its sheath bunches up and makes a nodule. This nodule has to glide in and out through the pulley and as it grows bigger, the finger locks down completely.

Diagram of the flexor tendon with pulley system

Diagram of the constrictive A1 pulley in cross section

Sympthoms

Trigger finger may present in a spectrum from infrequent triggering to the more extreme complete locking of the digit in flexion. Pain is commonly felt at the base of finger on the palm side. The first interphalangeal joint of the finger is frequently also painful. Typically forced extension might cause severe pain and even a sharp shooting pain. The finger might also be swollen.

Pain is commonly felt at the base of finger on the palm side.

Surgical Treatment

The problem is a mechanical problem and there is no medication that can reverse it. Steroid (cortisone) injections in the hand is considered early on and it is thought to reduce the swelling of the synovial sheath which might free up space for the tendon to glide more easily.

The definitive treatment is a surgical release of the A1 pulley that is the cause of the triggering.

The tendon is freed from surrounding tissue to ensure smooth gliding without further locking.

Expectations After the Operation

Active movement of the finger is encouraged immediately after surgery.

Complications after the Operation

Surgery on the pulley system

The affected finger might be tender after the release for a prolonged period.

Rehabilation After the Operation

Exercise

Tendon Glide Exercise