Paediatric trigger thumb: Diagnostic pearls.

Aim: The purpose of this study is to report diagnostic pearls and review the clinical presentation and outcomes of surgical treatment of paediatric trigger thumbs.

Methods: A retrospective review of medical records and imaging studies was performed on children with trigger thumbs from January 2009 to December 2019.

Results: Sixty-four trigger thumbs in 52 consecutive patients were treated. The average age at referral was 2.5 years. Symptoms include pain (4), triggering (14) and fixed contracture (38). The average symptom duration was 8 months. Forty patients had been evaluated and referred by a paediatrician or primary care doctor. Twenty-four of the 52 (46%) patients received hand x-rays and were initially misdiagnosed as a fracture or dislocation. Physical exam demonstrated a volar nodule in 64 thumbs (100%), fixed flexion deformities in 38 (73%) thumbs and triggering with active extension of the interphalangeal joint in 14 (27%) thumbs. The average age at surgery was 3.2 years. Follow-up averaged 12 months. Surgery resulted in complete relief of symptoms and correction of deformity. There was no reported loss of function or complication.

Conclusions: Children with trigger thumbs who ultimately undergo surgery present with distinct physical exam findings, including a volar nodule and a fixed flexion contracture. Understanding these pearls can minimise misdiagnosis of the condition as a fracture or dislocation. Highlighting trigger thumbs during musculoskeletal education for paediatric and primary care physicians is recommended. Surgical outcomes were excellent in patients aged 2-8 years old.