Abductor digiti minimi myocutaneous flap for opponensplasty in congenital hypoplastic thumbs.

Abstract

Although abductor digiti minimi transfer is a common form of opponensplasty for congenital hypoplastic thumbs, the inclusion of hypothenar skin with this flap--to create a myocutaneous flap--is not well-described. From a series of over 600 index pollicizations and hypoplastic thumb reconstructions performed from 1977 to 2007, 14 patients with congenital thumb hypoplasia are presented who had abductor digiti minimi myocutaneous flap transfer to improve thumb opposition. The primary indications for transfer were inadequate thumb opposition and aplastic palmar and thenar soft tissues. Follow-up ranged from 1 to 22 years. All 14 transfers survived and were successful in improving thumb opposition. Key pinch strengths averaged 40 percent of normal. The inclusion of the skin paddle eliminated routing the muscle through tight palmar soft tissues while improving thenar bulk and appearance. In select cases of congenital thumb hypoplasia, opponensplasty using the abductor digiti minimi myocutaneous flap is more advantageous than the traditional muscle transfer.