summary Congenital Trigger Thumb is a congenital pediatric condition of the thumb that results in abnormal flexion at the interphalangeal joint. Diagnosis is made clinically with the presence of a flexion deformity at the thumb IP joint. Treatment is nonoperative management with splinting for flexible deformities. Surgical A1 pulley release is indicated in fixed deformities beyond the age of 12 months. Epidemiology Prevalence 3 per 1,000 children are diagnosed by the age of 1 years Demographics separate entity to adult acquired trigger thumb male and females affected equally Anatomic location 25% are bilateral Risk factors etiology of pediatric trigger thumb remains unknown Etiology Pathophysiology pathoanatomy flexor pollicis longus (FPL) tendon is thickened due to abnormal collagen degeneration and synovial proliferation increased FPL tendon diameter, compared to the A1 pulley, causes disruption of normal tendon gliding Genetics most commonly an acquired condition some reports suggest autosomal dominance with variable penetration term congenital trigger thumb is now considered a misnomer Presentation History presenting complaint is usually fixed thumb flexion deformity at the IP joint history of trauma is rare family history of disease is rare Symptoms usually painless may be bilateral Physical exam inspection flexion deformity at the IP joint motion prominence of the flexor tendon nodule, referred to as "Notta's node" deformity may be fixed with loss of IP joint extension neurovascular usually preserved Imaging Radiographs recommended views AP and lateral views of the hand additional views dedicated thumb views indications recommended only if history of trauma findings usually diagnosed based on clinical presentation radiographs are usually normal Treatment Nonoperative passive extension exercises and observation indications not recommended for fixed deformities in older children technique passive thumb extension exercises duration based on clinical response outcomes 30-60% will resolve spontaneously before the age of 2 years old <10% will resolve spontaneously after 2 years old intermittent extension splinting indications first line of treatment more successful than observation alone consider alongside stretching regime flexible deformity not recommended with fixed deformity in older children technique splints maintain IP joint hyperextension and prevent MCP joint hyperextension duration for 6-12 weeks outcomes 50-60% resolution in all age groups high drop out rate from therapy Operative A1 pulley release indications fixed deformity beyond age of 12 months of age failed conservative treatment outcomes 65-95% resolution in all age groups Techniques A1 Pulley Release open release small transverse incision in the thumb MCP flexion crease, extending over the A1 pulley protect the radial digital nerve sharp dissection of the A1 pulley identify the Notta nodule in the FPL tendon watch nodule under direct vision during passive IP extension of the thumb to ensure there is smooth FPL tendon gliding Complications Digital nerve injury caution must be performed during release as digital nerves at high risk due to proximity to flexor tendon and A1 pulley Wound complications scar contracture abscess infection IP flexion deficit Bow-stringing of flexor tendon usually related to release of the oblique pulley Prognosis Natural history usually begins with notable thumb triggering that progresses to a fixed contracture spontaneous resolution unlikely after age of 2 years old