Detailed Anatomy and Reconstructive Approach of a Wassel VI Thumb Duplication

Abstract

Summary:. Thumb duplication is a congenital hand difference that occurs in 0.08 of every 1000 live births and is categorized by level of duplication by the Wassel classification system. The anatomy and reconstruction of type VI thumb duplication is not well described, likely due to its rarity. In this report, we detail the anatomy and reconstruction of an ulnar-dominant Wassel VI thumb duplication, with particular attention paid to management of the first CMC joint and intrinsic muscle rebalancing of the preserved digit.