Pediatric Trigger Thumb Release

A small transverse incision is made over the A1 pulley at the MP flexion crease of the thumb. Care is taken during dissection and release to avoid injury to the very superficial digital nerves of the thumb. The A1 pulley and any accessory pulley are released. The critical oblique pulley is left intact to prevent tendon bowstringing. Restoration of thumb IP joint hyperextension is ensured. Smooth movement of the tendon should be visualized to ensure proper release.

Pediatric trigger thumb most often presents as a fixed flexion deformity of the IP joint. Almost never truly present at birth, this deformity typically arises from an idiopathic relative size mismatch between the FPL tendon and the A1 pulley. Surgical release is indicated with failure of observation and conservative treatment (passive extension exercises and extension splinting) with deformity still present after 12 months of age. Release is also indicated after 2 years, as only 10% will resolve without surgery at this age.

No specific contraindications for this procedure exist. This procedure is typically elective, so general contraindications for routine surgery apply.

The patient is placed supine on the operating table, perhaps with a hand table attached based on the child‚½s size. A tourniquet is placed on the upper arm to allow for clear visualization during dissection.

Diagnosis is made based on history and clinical exam. Radiographs are typically normal, but might be helpful after a history of trauma which is sometimes reported by the family.

The nodule in the flexor pollicus longus tendon is called a Notta and appears at the A1 pulley at the MP flexion crease of the thumb and is often palpable under the skin on clinical examination. An accessory variable annular pulley may also appear, which typically needs to be released to completely fix the flexion deformity.

After 2 years of age, only 10% of trigger thumbs will resolve without surgery. Failure to treat the deformity may result in compensatory hyperextension deformity of the thumb MP joint.

As with any surgery, infection is a risk. Intraoperatively, the radial digital nerve is at risk due to its superficial crossing location near the A1 pulley and should be protected. Release of the more distal oblique pulley of the thumb may lead to bowstringing of the flexor tendon. After surgery, MP hyperextension deformity if pre-existing may or may not resolve. Additionally, relative thumb IP joint stiffness has been reported in patients with long standing trigger thumbs prior to surgical release.

As with any surgery, infection is a risk. Intraoperatively, the radial digital nerve is at risk due to its superficial crossing location near the A1 pulley and should be protected. Release of the more distal oblique pulley of the thumb may lead to bowstringing of the flexor tendon. After surgery, MP hyperextension deformity if pre-existing may or may not resolve. Additionally, relative thumb IP joint stiffness has been reported in patients with long standing trigger thumbs prior to surgical release.

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