Treatment of a Type 3B Hypoplastic Thumb Using Extra Phalanges From the Contralateral Duplicated Thumb: Case Report

A boy was born with a right duplicated thumb (Wassel type 6) and a left radial club hand (type 3) associated with a hypoplastic thumb (type 3B). He underwent surgical centralization of the left wrist when he was 13 months old. At age 38 months, he underwent reconstruction of the carpometacarpal joint of the hypoplastic left thumb. This procedure involved transplantation of the radial ray of the right duplicated thumb to the base of the left thumb. When he was 6 years old, the patient underwent an abductor digiti minimi muscle transfer to create opposition for the left thumb and deepening of the first web. At the final follow-up, he could grasp items in the first web space and pick up small items between the thumb and other digits of the left hand. The treatment represents a method of using otherwise discarded tissues for effective reconstruction.