Reconstruction of Thumb Defects Using the Second Dorsal Metacarpal Artery Flap with Two Pivot Points

BACKGROUND: This study aimed to introduce reconstruction of thumb defects using the second dorsal metacarpal artery (DMA) flap with two pivot points. METHODS: A retrospective study was conducted with 43 patients (group A) who underwent thumb reconstruction using the second DMA flap with two pivot points from July of 2012 to May of 2019. For comparison, the authors reviewed another cohort of 34 patients (group B) undergoing thumb reconstruction using the first DMA flap. Flap sensation and donor-site morbidity were assessed. RESULTS: In group A, the mean two-point discrimination was 8.7 mm (range, 6 to 12 mm) and 9.7 mm (range, 7 to 12 mm) on the innervated and noninnervated flaps at the final follow-up, with a significant difference (P = 0.012). In group B, the mean two-point discrimination of the flaps was 7.4 mm (range, 6 to 10 mm). By comparison, group B presented better discriminatory sensation than innervated flaps with double pivot points (P = 0.002). Based on the visual analogue scale score, the mean score of scar pain and appearance of the donor site were 0.1 (range, 0 to 3) and 0.4 (range, 0 to 2) in group A, and 0.5 (range, 0 to 3) and 1.0 (range, 0 to 4) in group B. By comparison, group A presented lower incidence of scar pain (P = 0.020) and better appearance of the donor site (P = 0.019). CONCLUSIONS: The second DMA flap with two pivot points has a long vascular pedicle, which allows the flap to repair thumb defects. It is associated with low donor-site morbidity but suboptimal sensory recovery. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.