Reverse Homodigital Dorsal Radial Flap of the Thumb.

BACKGROUND: Reconstruction of extensive distal defects of the thumb with exposure of bone, tendon, or joint can be a difficult problem because immediate closure is of paramount importance for preserving function and avoiding complications. Surgical treatment includes the use of local, reverse flow, and free flaps. The authors describe a new reverse homodigital flap to repair distal defects of the thumb. This flap is raised from the dorsal radial side of the first metacarpal area. It is pedicled on the dorsal radial collateral artery, which is constant for course, caliber, and communication with the palmar circuit. METHODS: The flap is raised by means of distal to proximal dissection, the skin island is incised at the periphery, and the subcutaneous pedicle is separated from superficial and deep tissues, leaving a certain quantity of loose tissue to protect the vascular axis. The digital sensory radial nerve is enclosed in the pedicle. The dissection must stop near the middle point of the proximal phalanx, which constitutes the pivot point of the flap. The flap is distally transposed and sutured on the deficit site. RESULTS: The homodigital dorsal radial flap was used on 16 patients to repair distal losses of substance of the thumb. The final results were good for reliability and coverage and from the aesthetic point of view for both the reconstructed area and the donor site. In pulp reconstruction, there was a good recovery of sensitivity, without a neural anastomosis being performed (the mean value of static two-point discrimination was 9 cm in this series). CONCLUSION: Wider use of this flap has helped to improve knowledge of dorsal vascularization of the thumb and to give another option for the repair of distal losses of substance of the thumb.