Purpose or Case Report: My purpose is to teach my audience about a congenital condition called Pediatric Trigger Thumb. My educational poster will include anatomy, causes, and symptoms associated with Trigger thumb and a pediatric ultrasound case that relate with a finding of Trigger thumb.
Methods & Materials: 3 years old girl presented as an outpatient with a history of bump or nodule to the base of her Left thumb for about a year. The ultrasound of left thumb was order to rule out the nodule and any structure anomaly.
Results: Musculoskeletal ultrasound of the left thumb was performed using Musculoskeletal (MSK) superficial setting. The series of longitudinal and transverse images were documented of the nodule area. Based on the sonographic evaluation of the palmar base of the left thumb demonstrated a well-defined ovoid predominantly hypoechoic lesion superficial to the flexor pollicis longus tendon (FPL). The lesion measures 6x1x5mm without vascularity on the color Doppler ultrasound. It did not exert mass effect on the underlying tendon but definitely demonstrated A1 pulley thickening. Dynamic scanning during passive flexion and extension showed difficult tendon gliding underneath the abnormal A1 pulley. This may represent the condition called Pediatric Trigger thumb.
Conclusions: In conclusion, Ultrasound should be an initial imaging study of choice for condition such as pediatric trigger thumb. Ultrasound can show varying degrees of flexor pollicis longus(FPL) tendinosis with a distinct nodule, A1 pulley thickening, and tenosynovitis. With ultrasound dynamic scanning is so beneficial to rule our Trigger thumb. Even color Doppler ultrasound plays a huge role in evaluating hyper vascularity in the region of the pulley and surrounding soft tissues. Thus, Ultrasound plays an important role in diagnosis congenital condition such as Pediatric Trigger thumb.