The use of keystone flaps for lower limb defects

Background: Local flap reconstruction uses local "like" tissue more effectively and takes less time during surgery than free tissue transfer.Objective: To assess the keystone flap as a versatile and reproducible coverage option for small and medium-sized lower limb defects, irrespective of the etiology. Additionally, we aim to reduce the rate of complications by conducting a preoperative dual assessment of the number of perforators, diameter, and peak systolic velocity in the suggested flap.Methods: This was a case series study conducted on 20 patients with small to medium-sized lower limb defects due to different etiologies at Kasr AlAiny Hospital between January 2022 and January 2023.Results: Out of 20 patients, 25% experienced complications, including failure rate, infection, wound dehiscence, and superficial sloughing. Treatment for complications included secondary sutures, repeated dressing, flap advancement, skin grafting, and debridement. Patients with complications had significantly more exposed structures in the distal tibia and other sites compared to those without complications. Patients with complications had a lower mean number of perforators and smaller average perforator diameter. The mean average perforator PSV was also lower in cases with complications. Nevertheless, there was insignificant variance in the mean defect-nearest perforator distance between the two groups.Conclusion: The keystone flap provides a stable, reproducible, and versatile solution for lower limb defects, with a simple, timesaving, single-stage procedure that minimizes complications compared to more sophisticated flaps, thanks to pre-operative duplex and perforator mapping.