Double-Barreled Free Vascularized Fibular Transfer in Large and Long Bone Defects

Free vascularized fibula is the most useful bony donor for long bone reconstruction in reconstructive microsurgery. It has many benefits, such as a very strong strut tubular bone, very reliable vascular anatomy with a large vascular diameter and long pedicle, and minimal donor–site morbity. In situations with huge long bone defects in the distal femur or proximal tibia and defective bony shape, the strength of the transplanted fibular bone is not sufficient enough, if only one strut of the fibula is transferred. The bony circulation of the fibula has two pathways, one from the nutrient artery via the peroneal artery through the nutrient foramen, which creates an endosteal arterial network inside the fibula; another is a periosteal network through an encircling vascular network of the bone, which distributes in the muscle sleeves of the fibular diaphysis. The authors modified the free vascularized fibular bone graft with a transverse osteotomy from the anterolateral aspect of the fibular shaft just distal to the entry of the nutrient artery. This produced two vascularized bone struts that may be folded parallel to each other, but that remain connected by the periosteum and muscle cuff surrounding the peroneal artery and veins. The proximal strut is vascularized by both periosteal and endosteal blood supply, whereas the distal strut is vascularized by a periosteal blood supply alone. This procedure can be called a “double barrel” free vascularized fibular graft. From 1984 to 2004, the author performed 11 cases of double–barreled fibular transplantation for large bone defects of the femur and proximal tibia. Average bone union took 7.8 months post procedure. There were no significant bone union time differences between both proximal and distal struts. After solid union of the transfered double–barreled fibular graft, there were no stress fractures in the series. The authors proposed the double–barrel free vascularized fibular graft as a useful method in cases with very large bone defects in large long bones, especially metaphyseal defects.