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Trigger Finger: Cause, Diagnosis and Treatment

Trigger finger can be

congenital (since birth)
acquired

Before reading further it would be good to first see Finger Anatomy (skip if you have already done so).

First we shall see the acquired type which is commonly seen in adults around the age of 45 years. It can result from overuse of the hand or no obvious cause may be present.

Other causes of acquired type include

collagen diseases such as scleroderma and Sjogren's syndrome
rheumatoid arthritis
osteoarthritis

Symptoms include

following flexion the finger extends with a jerk
a nodule can be palpated near the distal palmer crease
the nodule moves with finger movement
pain is present over the nodule

Snapping of the finger occurs when the covering of the tendon becomes constricted. Following this constriction a nodule develops in the tendon. The sliding in and out of this nodule through the constriction causes the snapping.

Diagnosis is by clinical examination. Investigations are hardly required.

Treatment of the acquired type includes

injection of steroid into the involved tendon sheath (I have had good results with this technique)
surgically cutting the constricted sheath to allow free movement of the tendon

Surgery is only done when there is no improvement after steroid injection or the triggering recurs after a single injection of steroid.

Congenital Trigger Finger or Thumb

This condition is more common in the thumb and involves both sides in 1/4 patients. It has been found to be associated with trisomy 13 (triplication of chromosome 13)

Only abnormality evident is persistent flexion posture of the involved digit. No snapping is present.

In about 25% patients it is detected at birth in the rest it is diagnosed within 2 years of age.

In 30% patients spontaneous resolution occurs. Rest require surgery.

Surgery should be done within three years of age as beyond this age chances of permanent deformity increase.