Pollicization of the index finger for reconstruction of the congenitally hypoplastic or absent thumb.

Between 1962 and 1980, 30 pollicizations of the index finger for congenital absence of the thumb were performed. None of the 30 index fingers were lost during the intraoperative or postoperative period. Of the 14 cases followed up on a long-term basis, six required secondary procedures, three for scar revisions; one, bone shortening; one, tenolysis of flexor tendons; and one, tenolysis of extensor tendons. All new thumbs showed normal sensibility. In four cases opposition was possible with all three residual fingers; in five cases, with the long and the ring finger; and in five cases, with the long finger only. Active motion averaged 42 degrees at the metacarpophalangeal (MP) joint of the new thumb and 35 degrees at the interphalangeal (IP) joint. The technique of pollicization has been modified over the years. Important steps are: correct skin incisions, complete destruction of the growth cartilage of the metacarpal head, fixation of the MP joint in maximum hyperextension, a rotation of 150 degrees, and the reconstruction of a musculotendinous shroud of the new thumb with the extrinsic and intrinsic tendons.