SN7 SHORT NOTE 5M

Define Trigger Finger. Describe its clinical features and management.

General Surgery · Final Professional

Definition

Trigger finger (stenosing tenosynovitis) is a condition in which a finger catches or locks in flexion and then snaps straight (‘triggers’). It is caused by a mismatch between a thickened flexor tendon (or a nodule on it) and the mouth of its sheath at the A1 pulley over the metacarpal head, so the tendon no longer glides smoothly.

Clinical Features

Patients report painful clicking, catching or locking of the finger, often worst in the morning; a tender nodule may be palpable over the A1 pulley in the palm, moving with the tendon. In advanced cases the finger locks in flexion and has to be passively straightened. The thumb and ring finger are commonly affected, and it is associated with diabetes and rheumatoid arthritis.

Management

Mild cases may settle with activity modification and NSAIDs. A corticosteroid injection into the flexor sheath is effective first-line treatment for most patients. Persistent or recurrent triggering is treated by surgical release of the A1 pulley (open or percutaneous), which reliably relieves the catching.

CLINICAL PEARL

The lesion is at the A1 pulley: a thickened tendon/nodule cannot glide through the sheath mouth, so the finger catches. A palpable tender nodule in the distal palm that moves with the finger is characteristic.

Congenital Trigger Thumb

A related condition in infants and young children is the congenital trigger thumb, in which the thumb is held flexed at the interphalangeal joint with a palpable nodule (Notta’s node) at the base; it is often noticed by parents as a fixed bent thumb. Many resolve spontaneously in early childhood, and those that persist are treated by release of the A1 pulley, so recognising it avoids mistaking a fixed flexed thumb for other congenital hand anomalies.

CLINICAL PEARL

The catch is at the A1 pulley: a steroid injection settles most trigger fingers, and a simple A1 release cures the rest.

DANGER / REMEMBER

Injecting or operating on a trigger finger in a patient with diabetes or rheumatoid arthritis requires extra care: these patients trigger more often, may have multiple digits involved, and heal less well, so glycaemic control and disease management are part of treatment, and repeated injections are avoided in favour of timely release.

Steroid injection into the sheath is effective in most cases.

KEY POINT

Key points TO remember

Stenosing tenosynovitis: finger catches/locks in flexion at the A1 pulley.
Painful clicking/locking + tender palmar nodule; thumb/ring finger; assoc. Diabetes, RA.
First-line: corticosteroid injection into the sheath.
Persistent/recurrent → surgical A1 pulley release.

EXAM TIP

Sources: Maheshwari's Essential Orthopaedics; Apley & Solomon's System of Orthopaedics and Trauma; AO Principles of Fracture Management.

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