Treatment of Complex Soft-Tissue Defects at the Metacarpophalangeal Joint of the Thumb Using the Bilobed Second Dorsal Metacarpal Artery-Based Island Flap

Background: The purpose of this study is to report on reconstruction of complex soft-tissue defects around the metacarpophalangeal joint of the thumb using a bilobed second dorsal metacarpal artery-based island flap taken from the dorsum of the proximal phalanges of the index and long fingers. Methods: From March of 2007 to October of 2009, the bilobed second dorsal metacarpal artery-based island flap was transferred in 13 patients. There were two defects on the metacarpophalangeal joint of the thumb. The mean size of the dorsal defects was 2.4 x 3.2 cm; the mean size of the volar defects was 2.6 x 4.0 cm. The mean size of the flaps taken from the index and long fingers was 2.6 x 3.4 cm and 2.8 x 3.2 cm, respectively. The mean pedicle length was 4.9 cm. Results: All flaps survived completely. At a mean follow-up of 14 months, the mean active motion arc of the thumb metacarpophalangeal joints was 42 degrees. The motion of the donor fingers was similar to that on the opposite side. The mean values of static two-point discrimination of the donor sites of the index and long fingers were 6 and 7 mm, respectively. Conclusion: Transferring the bilobed second dorsal metacarpal artery-based island flap is a useful and reliable technique for reconstructing complex defects around the metacarpophalangeal joint of the thumb.