Trigger finger is a condition where a finger becomes stuck in a bent position due to tendon inflammation.
Each finger has a flexor tendon that runs along its palm side, passing through a series of small fibrous tunnels called pulleys that keep it close to the bone as the finger bends. Trigger finger occurs when the tendon catches as it passes through the first of these pulleys, at the base of the finger, usually because the tendon has thickened slightly or the pulley has narrowed.
This catching produces the characteristic clicking, snapping or locking sensation as the finger bends and straightens, and in more pronounced cases the finger can become stuck in a bent position, needing to be straightened with the other hand.
The exact cause of trigger finger is often unclear. It is more common with repetitive gripping activities, and is recognised to occur more frequently in people with diabetes and rheumatoid arthritis. It is more common in women and typically develops in middle age, though it can occur at any age, including in children as a distinct, separate condition.
Common symptoms of trigger finger include:
Symptoms can affect more than one finger, and occasionally both hands.
Diagnosis is usually straightforward, based on the characteristic catching sensation and a tender lump at the base of the finger, found on examination.
Initial treatment includes activity modification and, for milder symptoms, a splint to rest the affected finger. A corticosteroid injection into the tendon sheath is often very effective, particularly for symptoms caught relatively early, and can resolve the catching without further treatment.
For symptoms that persist despite injection, or for a finger that is locking, trigger finger release is a straightforward day surgery procedure that widens the narrowed pulley, allowing the tendon to glide freely again.
The outlook for trigger finger is good. Many cases, particularly milder or earlier ones, respond well to a corticosteroid injection, sometimes resolving completely. For the smaller number of cases that need surgery, results are generally very reliable, with most patients experiencing complete resolution of the catching and locking.
Trigger finger is a common and generally very treatable cause of a catching or locking finger. Injection is often highly effective, particularly early on, and a simple surgical release is available for symptoms that persist. A finger that catches, clicks or locks when bending or straightening is worth having assessed.
