Second Dorsal Metacarpal Artery Flap From the Dorsum of the Middle Finger for Coverage of Volar Thumb Defect

Purpose The second dorsal metacarpal artery flap from the middle finger is a reconstructive technique that can be used to repair extensive volar defects in a normal-length thumb. However, few reports advocate using it for coverage of volar thumb defects. In this article, an anatomic study of 9 flaps used for resurfacing thumb defects is presented along with the clinical experience of the authors. Methods From 2004 to 2006, 9 patients (6 men and 3 women; mean age, 33 years; range, 18–51 years) with extensive volar defects of their normal-length thumbs had reconstruction using the described technique. In all cases, the first dorsal metacarpal artery flap technique was unable to be used because of injury. Donor sites were covered using full-thickness skin grafts. After surgery, the thumb was immobilized with a splint, followed by rehabilitation. During the follow-up period, which lasted 24 to 30 months, flap-site skin quality, scar contractures, and finger mobility were assessed. The range of motion of the hand was measured by a goniometer. Sensibility was evaluated by the 2-point discrimination test and the Semmes-Weinstein monofilament test. Cold intolerance was also assessed. Results Patient postoperative courses were uneventful, and all flaps survived completely without complication. Good coverage was obtained in all cases. Full active range of motion was observed in all patients in both the donor finger and the thumb. The mean Semmes-Weinstein sensitivity and 2-point discrimination scores of the flap were 4.02 g and 8.4 mm, respectively. Mild cold intolerance was observed in all of the thumbs. Conclusions The second dorsal metacarpal artery flap from the middle finger is a single-stage flap that produces good results. Although its pedicle length is limited, it is reliable and can be used as an alternative for reconstruction of extensive thumb-pulp defects, especially when the first dorsal metacarpal artery flap cannot be used. Type of study/level of evidence Therapeutic IV.