Treatment of mild hypoplasia.

Functionally, the thumb is the most important digit of the hand, allowing for numerous precise movements used in daily life. The thumb is a key factor in our ability to have a prehensile hand, the cornerstone of human evolution. The prehensile hand provides a variety of fine movements allowing for grasp, pinch, and the manipulation of objects. However, children with congenital anomaly of the hand, specifically thumb hypoplasia, have suboptimal thumb functioning. Depending on the severity of thumb hypoplasia, children may have hypoplastic or absent structures and joint instability. Many surgeons, including our practice, opt for early intervention to reconstruct the prehensile hand prior to developmental thumb use. Treatment of mild hypoplasia (types IIa, IIb, and IIIa) focuses on restoring thumb function and prehension, deepening the thumb-index webspace, and stabilizing the metacarpophalangeal joint. Herein we focus on our approach to creating a prehensile hand whilst specifically utilizing the abductor digiti minimi transfer.