Broad-pedicle posterior tibial artery perforator-plus and sural neurocutaneous flaps as two distally based options for moderate-sized distal lower-leg and ankle defects: a retrospective cohort study

Background Moderate-sized distal lower-leg and ankle defects can be reconstructed with local flaps when adjacent donor tissue and vascular territories remain intact. We assessed two anatomy-selected, non-interchangeable options: a broad-pedicle posterior tibial artery perforator-plus fasciocutaneous flap and a distally based sural neurocutaneous flap. Methods This retrospective cohort included 40 adults treated from January 2019 to January 2024 (20 per group). Allocation was anatomy guided rather than randomized. The primary outcome was complete flap survival; secondary outcomes included necrosis, venous congestion, other complications, revision surgery, operative time, protective sensation, ankle motion, ambulation, and follow-up. Welch t tests, Fisher exact tests, and a Pearson chi-square test were used; effect estimates are reported with 95% confidence intervals (CIs). Results Defect location differed between groups ( P = 0.002). Complete survival occurred in 19/20 posterior tibial flaps (95%) and 15/20 sural flaps (75%) (risk difference, 20.0% points; 95% CI, -3.2 to 42.3; P = 0.182). Venous congestion occurred in 1/20 (5%) and 7/20 (35%), respectively (risk difference, -30.0% points; 95% CI, -52.1 to -4.9; P = 0.044). Operative time was shorter in the posterior tibial group (mean difference, -18.4 min; 95% CI, -26.3 to -10.5; P < 0.001). Functional findings were exploratory because standardized preoperative baselines were unavailable. Conclusions Anatomy-guided allocation introduced selection bias and limits direct comparison and causal inference. The findings support individualized, territory-based reconstruction rather than a hierarchy of superiority. The posterior tibial perforator-plus option may suit medial defects requiring limited-arc transfer, whereas the sural flap remains useful for posterolateral, lateral-malleolar, heel, and Achilles-region defects when its distal perforator territory and venous pathway are intact.