Peri-knee soft tissue reconstruction using retrograde pedicled anterolateral thigh flaps with selective vascular supercharging: a retrospective study

Soft tissue defects around the knee create significant reconstructive difficulties owing to complex anatomy, high functional demands, and exposure of vital structures. The retrograde pedicled anterolateral thigh flap (RPALT), supplied via the descending branch of the lateral circumflex femoral artery, provides an alternative to free tissue transfer. Retrograde perfusion can compromise distal flap viability, especially when larger flaps undergo extensive rotation. We evaluated the clinical outcomes of peri-knee reconstruction using RPALT flaps with standardized intraoperative perfusion assessment followed by selective vascular augmentation if indicated. We conducted a retrospective review of 23 consecutive patients who underwent peri-knee reconstruction with RPALT flaps (January 2015–August 2025). Following flap rotation, distal perfusion was assessed during a mandatory 40-minute observation period using color, temperature, capillary refill, and distal bleeding (CTCD criteria). Persistent perfusion compromise prompted mechanism-specific augmentation (venous, arterial, or combined). The primary outcome was flap survival; secondary outcomes included Hospital for Special Surgery (HSS) knee score, Vancouver Scar Scale (VSS), Scar Cosmesis Assessment and Rating (SCAR) scale, follow-up duration, and complications. Patients (mean age 38.48 ± 11.03 years) had defects in the prepatellar region ( n = 9), lateral knee ( n = 8), and popliteal fossa ( n = 6), predominantly from trauma. Eight patients (34.8%) required vascular augmentation: venous in 4, arterial in 2, and combined in 2. All flaps survived with no total flap loss (mean follow-up 35.26 ± 22.25 months). One patient experienced a postoperative vascular crisis, which was successfully salvaged with timely intervention; another had marginal proximal partial skin loss/necrosis managed with limited skin grafting. Mean HSS score was 79.57 ± 7.87, mean VSS was 3.13 ± 0.81, and mean SCAR was 5.74 ± 1.05. The augmentation group had significantly larger defect and flap areas ( P = 0.034 and P = 0.015), whereas functional and scar outcomes were comparable between groups. In this selected cohort, RPALT flap reconstruction guided by standardized preoperative ultrasonography mapping and structured intraoperative perfusion assessment achieved excellent flap viability with satisfactory functional and cosmetic outcomes. Selective vascular augmentation was more frequently required for larger defects and flaps and may enhance reliability in higher-demand peri-knee reconstruction.