The posteroanterior and lateral radiographs of the hand of an 18-month-old girl showed a sixth digit growing from the posterior surface of the hand. (See Fig. 1.) This radiographer had seen extra digits on patients before. However, the extra digit usually is extremely rudimentary, and sometimes attached by a small stalk. This patient was different. The extra digit was complete, including metacarpals and phalanges. The Solution Extra digits, also known as polydactyly, sometimes present as an isolated finding but often are part of a syndrome. Polydactyly also can occur as a dominant inherited trait in families. In its most common form, the extra digit is attached on the little finger side of the hand.
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