Management of thumb hypoplasia.

This chapter emphasizes the dilemma of salvage and reconstruction of the congenitally aplastic or hypoplastic thumb without normal cerebrocortical representation for prehensile grasp and pinch. The philosophy of reconstruction of the congenitally anomalous thumb is clearly divergent from thumb reconstruction following trauma. It is difficult to advise parents who seek surgical correction of the severely deficient thumb ray that amputation is the procedure of choice, to be followed by transfer of an otherwise normal digit to become a functional thumb unit. The psychological impact of these recommendations may be devastating to parents. Informed understanding of the likely progressive development of index-middle finger scissoring, pronation of the index ray with spontaneous broadening of the pulp, and the deteriorating use of an existing hypoplastic thumb may make the decision for ablation easier for parents. It is critical that these decisions be made through careful education and understanding, considering always the overall grasp-and-pinch capability of the hand as a whole. Reconstruction of the aplastic or hypoplastic thumb is an exciting and challenging area of hand surgery. The rewards are improvement in grasp and pinch either by functional integration of the reconstructed part, or by complete replacement of the deficient thumb by tissue from adjacent or distant donor sites. Success is measured not only in terms of cosmetic appearance, but as enhanced capacity of the child's hand in all activities of daily living (Fig. 39A and B).