[Reconstruction for dysplastic polydactyly of thumb with an island compound flap].

There is always one developed PDAA in extra thumb, which can be used to design a flap. The longitudinal advanced flap can also eliminate the tension caused by unequal length in two thumbs. Using an axial or island flap to reconstruct a new thumb can not only change the appearance, but also make the reconstructed thumb acquire two sets of blood supply and nerve system.