Radiologic findings of the flexor pollicis longus hypoplasia

A case of a 10-year-old boy with hypoplasia of the flexor pollicis longus and without other associated anomalies and trauma history is reported. Flexor pollicis longus tendon anomalies are rare; several types of this congenital anomaly have been reported in the literature. The diagnosis should be considered to the conditions of a patient who was unable to flex the interphalangeal joint of the thumb. Hypoplastic thumb or absent interphalangeal joint crease may be a diagnostic feature in such cases. We preoperatively present the radiological findings of this rare congenital anomaly. Ultrasound and magnetic resonance imaging (MRI) features have never been reported in the literature. (orig.)