The deformities of the fingers and toes

by William Anderson

SUPERNUMERARY FINGERS AND TOES.

The occasional occurrence of supernumerary fingers and toes is well known. As a rule the extra digit is a mere pediculated appendage bearing a nail and a more or less perfect representative of the ungual phalanx; in other cases, however, it is complete and well formed, and furnished with a metacarpal or metatarsal bone of its own, or sharing the proximal bone with a neighbouring finger or toe. In rare instances the digits may undergo still further numeral increase even to a complete duplication of the normal complement.

The condition is commonly bilateral, and may affect all four extremities. It is liable to association with syndactyly and other congenital deformities, and it is occasionally handed down by inheritance as a family peculiarity. Sir William Lawrence refers to a condition of the kind which was traced through four generations, and other examples are on record.