Successful Transfer of a Vascularized Fibular Osteocutaneous Bone Graft Harvested Distal to a Previously Fractured Fibula

Abstract

A literature search revealed one published case report in which a previously fractured fibula was used as a free vascularized fibular bone graft. The segment of fibula used was 3 cm proximal to the previous fracture site and was hypothesized to be within the “zone of injury.”1 Our case study, however, is the first report of a free vascularized fibular osteocutaneous transfer in which the fibula was harvested distal to a previous fracture and was therefore completely dependent on its periosteal, and not endosteal, blood supply. A 17-year-old boy sustained a grade IIIB open fracture of the left tibia and fibula (Fig. 1) and a closed fracture of the right tibia and fibula. After serial debridement, a 13-cm segmental tibial defect and a 15 × 8-cm soft-tissue defect (covered with a split-thickness skin graft) remained over the anteromedial aspect of the distal third of the lower leg.Fig. 1.: Grade IIIB open comminuted fracture of the left tibia and fibula.Eight months later, a vascularized free fibular osteocutaneous transfer, using the previously fractured right fibula, was performed. A portion of the flexor hallucis longus was left attached to the fibula to help preserve the periosteal circulation and fill the soft-tissue defect. A distal osteotomy was performed 6 cm proximal to the lateral malleolus, and the proximal osteotomy was made proximal to the fracture site. A 13-cm segment of fibula was harvested 3 cm distal to the previous, now-healed fibular fracture (Fig. 2). Examination of the proximal peroneal artery under the operating microscope showed no evidence of vascular intimal injury.Fig. 2.: Previously fractured, vascularized free fibular osteocutaneous graft.The fibula was then dowelled into the tibia and fixed with two cortical screws. End-to-side anastomosis of the peroneal artery to the recipient posterior tibial artery and end-to-end anastomosis of the peroneal venae comitantes to a posterior tibial vein were performed. Excellent blood flow was re-established to the fibula, flexor hallucis longus, and skin flap. The remaining soft-tissue defect was closed with a split-thickness skin graft. The skin flap showed excellent color and capillary refill and a strong Doppler signal throughout the postoperative course. The flap and split-thickness skin graft healed completely. Two years postoperatively, radiographs confirmed a solidly united tibia and the patient was ambulating pain-free (Fig. 3).Fig. 3.: Radiographs of the left tibia and fibula 2 years postoperatively (left, anteroposterior view; right, lateral view).This is the first report of successful transfer of a free vascularized fibular osteocutaneous bone graft in which the entire segment of fibula was harvested distal to a previous fracture. Previous fracture of the fibula may be associated with damage to its vascular supply and may jeopardize the viability of a vascularized free fibular bone graft. Normally, 70 percent of the cortex is supplied by the longitudinal endosteal circulation, which would become completely disrupted by a fracture of the fibula. The remaining 30 percent of cortical blood supply originates from the periosteum.2 When a free fibular transfer is performed several months after the initial injury, the fracture in the donor fibula will have healed, and it might be assumed that the cortical blood supply has been reconstituted. On the basis of this one case, we believe that, in rare circumstances, a free vascularized fibular osteocutaneous bone graft may be harvested distal to a healed previous fracture of the fibula without compromising its viability. ACKNOWLEDGMENT The authors thank Ryan Karlstad, M.D., clinical fellow, at the UCLA Medical Center, Los Angeles, California. Ruby Grewal, M.D. Hand and Upper Limb Center London, Ontario, Canada Norman Y. Otsuka, M.D. Department of Orthopedic Surgery UCLA School of Medicine Shriners Hospital for Children Los Angeles, Calif. Neil F. Jones, M.D. Division of Plastic and Reconstructive Surgery Department of Orthopedic Surgery UCLA School of Medicine Hand Surgery UCLA Medical Center Los Angeles, Calif.