A COMPREHENSIVE APPROACH TO SURGICAL-MANAGEMENT OF THE TYPE IIIA HYPOPLASTIC THUMB

In order to adequately identify pathologic anatomy and effectively rec onstruct 14 type IIIA hypoplastic thumbs, a comprehensive clinical eva luation and surgical approach was employed. Eleven patients had congen ital differences in the forearm, while all patients had anomalies in t he wrist, hand, and digits. In addition to well-described interconnect ions between the flexor pollicis longus and the extensor pollicis long us, and thenar muscle hypoplasia, the authors observed duplication of musculotendinous units, anomalous muscles between the thumb and index rays, and abnormal insertions or dense adhesions along tendons as prox imal as the forearm level. Successful reconstruction required an exten ded approach from the digit to the forearm, through which division of abnormal connections, reorientation of tendons, and lysis of adhesions was performed. Opposition transfer was needed in only 8 of the patien ts after the other pathologies were treated. Web-space deepening and u lnar collateral ligament reconstruction was performed when indicated. Improvement in function and appearance was achieved. Copyright (C) 199 8 by the American Society for Surgery of the Hand.