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 ...

A locus for triphalangeal thumb, variably associated with pre-axial polydactyly, was previously identified in the zone of polarizing activity regulatory sequence (ZRS), a long range limb-specific enhancer of the Sonic Hedgehog (SHH) gene at human chromosome 7q36.3. Here, we demonstrate that a 295T>C variant in the human ZRS, previously thought to represent a neutral polymorphism, acts as a domi...

A rare association of triphalangeal thumbs and duplication of the big toes is described. The family pedigree confirms autosomal dominant inheritance with marked penetrance. A systematic approach to the diagnosis of this anomaly is presented. The distinction between the two types of triphalangeal thumb, true (opposable) and finger-like (non-opposable), is emphasised.

radial polydactyly, the most common digital duplication in asian and white populations, has a wide range of manifestations. its classification is useful for planning and assessing surgical treatment. our patient had four thumbs, duplicated radial carpal bones, and a bifurcated radius. this presentation is not covered by any of the current classifications. to the best of our knowledge, this is t...

We report a case of Klinefelter's syndrome owing to maternal meiotic error associated with triphalangeal thumb and delta phalanx bilaterally. There are no previous reports of similar cases and triphalangism with delta phalanx abnormalities of both thumbs might therefore be considered a further, but rare, manifestation of this aneuploidy.

preaxial polydactyly is the most common duplication pattern in white and asian populations (1). it is a congenital anomaly with a wide range of manifestations .current classification do not have the capacity to classify all different types of radial polydactyly. we describe here a very rare and unusual case of bilateral preaxial polydactyly (triplication) in a woman and report the operations re...

BACKGROUND The purpose of this study was to present a novel surgical technique using an on-top osteotomy and to assess the clinical and radiographic outcomes for the triphalangeal Wassel type VI thumb duplication patients. METHODS The surgical technique involves ablation of the radial thumb at distal one-third of the metacarpal, corresponding metacarpal osteotomy of the ulnar thumb, with amal...