A graft scaffold geometry is provided for use in the repair of segmental large bone defect. The scaffold geometry has a first (central) conduit with one or several hook-shaped chamber, which form a second conduit, integrated to the lateral side of the scaffold. The purpose of the hook-shaped chamber(s) is three-fold: 1) to facilitate the insertion and containment of biological augmentation constructs, such as growth factor-impregnated carrier devices; 2) stabilize the local surrounding soft tissue envelope to allow ingrowth of new blood vessels; and 3) to improve the manipulation of the composite bone free flap during implantation. Whether one or all of these mechanisms are active in a given situation, the overall result is that the hook chamber enables enhanced containment of graft-augmenting synthetic osteoinductive constructs, prevents their displacement, and maintains their proximity to the scaffold, thus improving the chances of success of the graft.