Isolated bilateral triphalangeal thumb with delta phalanx: a case report

Triphalangeal thumb is characterized by the interposition of an extra-phalanx between two normal ones. In this article the authors present the case of a 24-year-old man with bilateral triphalangeal thumb of opposable type, without any other associated anomaly or genetic syndrome. The patient had triangular delta extra-phalanxes that caused ulnar deviation of both thumbs. Surgical procedure for the correction of the congenital anomaly consisted of a closing wedge osteotomy and distal interphlangeal joint arthrodesis in the left thumb, and a wedge osteotomy in the deformed distal phalanx of the right thumb. Appearance and precision function of hands considerably improved 6 months after the operation, and there was no major stiffness in proximal interphalangeal joints of thumbs.