BackgroundComplex orthoplastic lower limb trauma in individuals with multiple injuries requires considerable resources and interdisciplinary collaboration for good outcomes. We present the first reported end-to-side free flap microanastomosis for lower limb trauma reconstruction involving a peronea arteria magna without radiographic collaterals.Case presentationA 55-year-old Caucasian gentleman involved in road traffic collision sustained an open tibial fracture on the anteromedial distal third of the left lower leg with local degloving and a subtotal right foot and ankle degloving. Both injuries were reconstructed with free tissue transfer. A left lower limb peronea arteria magna successfully received a free gracilis muscle flap by end-to-side microanastomosis and perfusion of the foot was preserved. This rare anatomical variant and its anatomy is reviewed, as well as a description of the suggested preoperative planning and technique for reconstruction.ConclusionsSuccessful free flap reconstruction may be performed to a lower limb with a peronea arteria magna recipient as the lone vessel supplying the foot in trauma, although preoperative counseling of the risks, benefits, and options are essential.Level of evidenceLevel V, case report