Dolph Houben

43 Vascularized Bone Grafts, a closer look at the free fibula flap 2 In the femur, the fibula is prone to a stress fracture if not protected from direct mechanical loads. Therefore, the free intramedullary placed fibula can be augmented with a size-matched structural allograft and stabilized with a spanning plate [67] . Eccentrically placed fibulas are for the same reason often supported by a locked IM nail. The third option for fibular placement in femoral reconstruction is the onlay technique where the fibula is placed on top of a cortical allograft [57] . All methods call for rigid internal fixation. The final option for femoral reconstruction is a double- barrel flap. With this technique, the free fibula is osteotomized at its midpoint without dividing the vascular pedicle after harvest. This produces two vascularized bone grafts that require only one set of vascular anastomosis and provides the double cross-sectional area of a single fibula transfer when placed in a single bone [60] . For mid-femoral defects, the superficial femoral artery and vein can be used as recipient vessels for most mid femoral defects with side-to-end anastomosis for the artery and end-to-end venous anastomosis. In proximal defects, the lateral femoral circumflex vessels can be used. For very distal femoral defects the popliteal vessels can be used in an end-to-side fashion, through a posterior approach. If possible, the anastomosis is best made to the superficial femoral artery in distal defects since the approach to the popliteal vessels often requires the intra-operative turning of the patient. Secondly, the anastomosis will be in an area where joint mobility can play a factor in blood flow disturbance [57] . Figure 5: post-operative X-ray of a large segmental defect reconstructed with a free fibula graft and fixed with external fixation (A), Post-operative X-ray of a large defect of the femur reconstructed with an allograft combined with a free fibula graft as onlay graft to increase healing (B).