Trigger thumb in children

In short: in paediatric trigger thumb the last joint of the thumb (interphalangeal) stays bent and does not fully extend. At the base of the thumb, on the palm, a small thickening of the tendon called Notta's node is often palpable. It is not a traumatic injury, in most cases it is not painful, and a proportion of children go on to resolve spontaneously.

In short

The tendon that flexes the thumb runs inside a sheath, passing under a pulley. When the tendon thickens at that point, gliding becomes difficult: the digit locks in flexion, or moves from flexed to extended with a perceptible snap. In children, unlike adults, the most frequent picture is not true triggering but a persistently bent thumb.

Parents usually notice it between the first and third year of life, often suddenly ("it wasn't there yesterday"), simply because it had not been noticed before. It is not caused by trauma or by anything the parents did, and in most cases the child has no pain and uses the hand normally.

Symptoms and when to worry

The typical sign is fixed flexion of the interphalangeal joint of the thumb, with difficulty or inability to straighten it passively. On palpation of the thumb base, on the palmar side, a small firm nodule is often felt, moving with the digit.

Features that deserve assessment: involvement of several digits, stiffness of other joints, real pain, asymmetry or other general signs, and onset after trauma. In those cases the picture may not be a simple trigger thumb and other conditions must be considered.

Diagnosis and imaging

Diagnosis is clinical and does not require routine investigations. Resting thumb position, passive extension achievable, presence of the nodule, mobility of the other digits and functional use of the hand in play are assessed. X-ray is not needed in the typical picture; it is considered only when atypical features are present. The most important distinction is from congenital clasped thumb, where the nodule is absent and the limitation involves the metacarpophalangeal joint.

Conservative treatment

There are three options, and none is mandatory for everyone.

Observation is reasonable in young children with an isolated picture and good hand function: a proportion of cases resolve spontaneously, and waiting does not compromise the result of later treatment. Passive stretching taught to parents and night extension splinting may be offered in selected cases, aiming to maintain or improve extension; their effectiveness is variable and not universal. In both cases the pathway is reviewed periodically, without setting a rigid deadline.

When surgery is needed

Surgery consists of releasing the pulley that obstructs tendon gliding and is a well-established procedure. It is considered when flexion persists over time, when it genuinely limits use of the hand, or when observation and conservative treatment have not changed the picture.

There is no surgical age valid for everyone. The decision takes into account how long the picture has lasted, joint stiffness, functional impact and family preferences, discussed with those who routinely perform paediatric hand surgery.

Follow-up and recovery

After surgery, recovery of movement is usually quick in children and does not require formal rehabilitation in most cases. In conservatively managed children, reviews serve to check achievable extension and to detect stiffness that is becoming established. For general hand mobility exercises see the exercises section for parents.