Anatomical Study of Preaxial Polydactyly in 158 Hands

Abstract

ISLAM, S., OKA, I. and FUJITA, S. Anatomical Study of Preaxial Polydactyly in 158 Hands. Tohoku J. Exp. Med., 1992, 168 (3), 459-466 - Preaxial polydactyly is a common congenital hand anomaly. Here in 138 patients with 158 duplicated thumbs, a new classification of this anomaly was done from analysis of radiographs and operation records. Initially all the duplicated thumbs were arranged into from Type I to VII on the basis of radiological extent of bifurcation. Appendage type was noted as a separate entity. Type IV was found the most common and had 53 thumbs (33.6%) involved. But findings on surgery indicated that the exact level of bifurcation varied in each type, and Type VII became three times as frequent as previously noted from x-ray examination at the time of surgery. Radiologically encountered duplications at IP (Type II), MP (Type IV) and CM (Type VI) joints were specifically classified into five groups from A to E on the basis of the structural changes detected on surgery. Details in each group were discussed. - congenital anomaly; thumb polydactyly; classification