RESUMEN
Congenital malformations of the thumb greatly affect the performance of the hand and the upper limb. The conditions associated with atrophic thumb represent a wide spectrum of abnormalities, ranging from a complete absence to a mere small size of the thumb. A 5-year-old Caucasian female presented with congenital clasped thumb deformity with hypoplastic thumb and with an absence of extrinsic extensors extensor pollicis longus and brevis and with stable carpometacarpal joint. We managed this case by transferring the extensor indicis proprius tendon and flexor digitorum superficialis of digitus medicinalis (the ring finger)-which is not common-to compensate for the absence of extension and abduction tendons of the thumb. After 17 years, the result was satisfactory for the patient and her family. She was able to use her hand for writing and doing normal daily work without feeling any disability.