Dr. Bobby Chhabra treats conditions like thumb duplication as an orthopaedic hand surgeon. Thumb duplication, also called pre-axial polydactyly, is a congenital defect where a child is born with more than one thumb per hand, though the thumbs are often smaller and less developed. The thumbs can be fused together or separate, and may be accompanied by defects in other fingers. Unlike duplications in other fingers, duplicate thumbs have divided bones, tendons, and muscles between them, complicating surgical solutions. Children usually must wait until ages 1-2 for anesthesia before reconstructive procedures can begin to address functional and cosmetic limitations.

1. An Overview of Thumb
Duplication in Children
By Bobby Chhabra

2. Introduction
• Dr. Bobby Chhabra currently serves as team physician
and orthopaedic hand surgeon at the University of
Virginia. In this position Dr. Bobby Chhabra frequently
treats conditions such as elbow arthritis and wrist
arthritis. He also has experience with congenital defects
such as thumb duplication.
Pre-axial polydactyly, more commonly referred to as
thumb duplication, can be described as a congenital
defect that involves a child being born with more than
one thumb on the same hand. Thumb duplication can
appear in a variety of ways, though in most cases both
thumbs are smaller than normal and less than fully
developed.

3. Thumb Duplication in Children
• The thumbs may grow fused together or as two separate
fingers. The thumbs may or may not be accompanied by
defects or polydactyly in other fingers, though the defect
occurring in both hands is unlikely.
Unlike duplications in other fingers, duplicate thumbs
have bones, tendons, and muscles that are divided
between the two thumbs, complicating the prospects of a
straightforward surgical solution. Generally a child must
wait until the age of 1 or 2, when anesthesia can be
tolerated, before doctors can begin the reconstructive
processes that address both the functional and cosmetic
limitations of pre-axial polydactyly.