Reconstruction of congenital aplasia of digits.

Reconstruction of partial digital aplasia with one border digit is attainable in young patients. It requires construction or transplantation of a stable part with functional sensibility to permit pinch and grasp. Toe transplants provide these functions relatively rapidly but carry a certain risk of failure and add a new deformity to the foot. The construction of a skin mitten by unfolding of the dorsal flap in the affected limb requires additional skin cover from a distance. Stabilization with a bone graft is done at a later stage. If the border digit is hypoplastic, staged autogenous bone grafts permits attainment of greater length. Using bone with epiphyseal plate from the toes of young children does not always result in growth. The assessment of regained sensibility in our patients was done with two-point discrimination but was not reliable in children under age seven. Sensibility in the unfolded flap was regained gradually over a long period of time. The longest follow up in this group was 11 years: the patient attained two-point discrimination of 7 mm. Published experiments with the denervated skin of laboratory animals demonstrated some return of sensibility through nerve sprouting. The pathway of sensibility in the denervated unfolded dorsal flap is continuity with volar intact skin is not known but is presumed to require some form of nerve sprouting. The advantages of using the unfolded dorsal flap are that in lengthens palmar skin without an intervening scar or unpleasant paresthesia and does not produce a defect in the foot.