Triphalangeal Thumbs in the Pediatric Population: Long Term Outcomes Following Surgical Intervention

A triphalangeal thumb is a thumb with three phalanges. The thumb often appears long and fingerlike, and can sometimes be in the same plane as the other fingers. Anatomically, the extra phalanx can have different shapes. Several classification systems have been used, but the simplest and most often used is the Wood (1976) classification by the shape of the extra phalanx. If the extra phalanx is triangularly shaped it is classified as a type I. Type II has a rectangular shaped extra phalanx but it has not developed as a full phalanx. Type III is a full extra phalanx.