Bilateral Hypoplastic Thumbs with Syndactyly of the Index Fingers Treated by Pollicization: A Case Report

Abstract

Hypoplastic thumb can range from a slight decrease in thumb size to complete absence of the thumb based on the modified Blauth’s classification. Pollicization of the index finger is indicated for cases with Blauth type IIIB or greater. We present a case of bilateral hypoplastic thumbs with syndactyly of the index fingers, both of which could not be identified by Blauth’s classification. We sequentially performed pollicization of the index finger. There were several anomalies in the index finger, which further required modifications in the pollicization procedure. Tip and pulp pinches as well as precision grip were achieved by 11 months after pollicization on the right hand. Meanwhile, functions were more restricted on the left hand, probably due to initial low quality of the left index finger. This type of hypoplastic thumb should be distinguished from the typical hypoplastic thumb classified by Blauth, in terms of embryogenic background and strategy of thumb reconstruction.