Vascularized bone grafts and their applications in the treatment of carpal pathology.

Vascularized bone grafts (VBGs) are techniques in the management of certain types of carpal pathology. VBGs have traditionally been advocated for conditions including delayed and nonunion of fractures and avascular necrosis. The most common indications for VBG have been for scaphoid nonunion, lunatomalacia (Kienböck's disease), and osteonecrosis of the scaphoid (Preiser's disease). Advantages over NVBG have been established. VBGs provide improved blood flow, osteocyte preservation, and accelerated healing rates. Local pedicled VBGs are the most commonly used methods. They are technically less demanding than are free VBGs and are associated with less morbidity. Commonly used donor grafts arise from the dorsal vasculature of the wrist and include the 1,2 intercompartmental supraretinacular artery (1,2 ICSRA), the 2,3 ICSRA, the fourth extensor compartment artery (fourth ECA), and the fifth ECA. A 4 + 5 ECA combination graft has been described to provide a longer pedicle. In managing osteonecrosis, most surgeons would agree that VBG should be reserved for carpal bones with an intact cartilaginous shell and no collapse. In treating scaphoid pathology, indications for VBG include fractures/nonunions with proximal pole avascular necrosis and/or small proximal pole fragments.