Adult presentation of locked 'congenital' trigger thumb: A case report

Introduction and importance: Although 'congenital' or paediatric trigger thumb is commonly seen in the paediatric age group, adult presentation is very rare. However it is crucial to acknowledge the occurrence of unusual manifestations of paediatric trigger thumbs, since paediatric trigger thumbs are considered a separate disease entity compared to the commonly seen stenosing tenosynovitis in adults.Case presentation: We report a case of a 18-year-old young lady presenting with atraumatic locked trigger thumb, which was successfully treated surgically with intra-operative finding confirming abnormally thickened flexor pollicis longus tendon signifying a paediatric trigger thumb pathology.Clinical discussion: Adult and paediatric trigger thumbs have different aetiology, with thickened A1 pulley and tendon sheath being the culprit in adults, whereas in paediatric thumbs thickened tendon nodules (Notta's node) are usually the causes of triggering. Conclusion: This uncommon presentation in this case report is atypical in the age group presentation of paediatric trigger thumb, and should be distinguished from the usual trigger thumb pathology in adults. Although a transient period of extension lag in the early post-operative period may be evident, it can still be successfully treated with surgical release.