Comparative Efficacy of Antegrade Versus Retrograde Island Flaps Based on the Second Dorsal Metacarpal Artery With Nerve Anastomosis for Thumb Soft Tissue Defect Repair

AIM: This study seeks to compare the clinical outcomes of antegrade versus retrograde second metacarpal dorsal artery island flaps with nerve anastomosis, thereby providing evidence-based guidance for surgical decision-making. METHODS: This single-center retrospective study included 180 patients with thumb soft tissue defects treated via nerve-anastomosed second metacarpal dorsal artery island flaps between December 2021 and December 2024. Among them, 96 underwent antegrade island flap repair (antegrade group) and 84 received retrograde island flap repair (retrograde group). Key evaluated metrics included surgical parameters, sensory recovery indicators [static two-point discrimination (s2PD), British Medical Research Council (BMRC) sensory grading], motor function metrics [interphalangeal joint range of motion (ROM), grip strength, and pinch strength], and postoperative complication rates. RESULTS: The antegrade group demonstrated significantly longer operative times and higher intraoperative blood loss than the retrograde group (p < 0.001). The antegrade group exhibited superior s2PD at both 3-month and 6-month postoperative assessments (p < 0.05). 6 months postoperatively, 81.25% of antegrade group patients reached S4 grade compared to only 42.86% in the retrograde group (p < 0.001). For motor function outcomes, the retrograde group displayed significantly greater interphalangeal joint ROM at 1 month and 3 months after surgery (p < 0.05). This difference was no longer present by 6 months (p > 0.05). No significant differences were observed in grip or pinch strength between groups at either postoperative 3- or 6-month evaluations (p > 0.05). Multivariable analysis confirmed the antegrade group's advantages in sensory restoration (p < 0.05), while the retrograde group retained a substantial benefit in early ROM recovery (p < 0.001). Additionally, venous crisis was observed less frequently in the antegrade group (p < 0.05). CONCLUSIONS: For soft tissue reconstruction of the thumb, both antegrade and retrograde second dorsal palmar artery island flaps combined with nerve anastomosis are feasible options. The antegrade approach is beneficial for the recovery of sensory function, while the retrograde approach is beneficial for early joint mobilization and has less surgical trauma. The choice of surgical approach should be based on clinical needs.