Polydactyly means that more than the normal 5 digits. Typically patients have either an extra thumb or an extra pinky.
|A patient with radial polydactyly (extra thumb).|
Syndactyly is the abnormal joining of the fingers. It is most common between the middle digits but can affect any of the fingers.
|Syndactyly of the fingers.|
While these conditions are uncommon, each is one of the most common birth (i.e., congenital) anomalies of the upper extremity. And both typically do well with surgery. I have previously posted several times on both syndactyly and polydactyly.
|Left hand, central polysyndactyly.|
|Right hand, central polysyndactyly.|
|Right and left hands, central polysyndactyly. Note the differences between the right and left sides. There is a “bizarre” collection of bones rather than the typical straight fingers.|
My Bio at Washington University