MICRO-VASCULAR FREE BONE TRANSFER WITH REVASCULARIZATION OF THE MEDULLARY AND PERIOSTEAL CIRCULATION OR THE PERIOSTEAL CIRCULATION ALONE - A COMPARATIVE EXPERIMENTAL-STUDY

Two different types of vascularized rib grafts presently are used in [human] clinical practice and as experimental models for investigations on free microvascular bone transfer: the posterior rib graft, including both medullary and periosteal blood supply to the bone; and the posterolateral segmental rib graft, supplied by periosteal vessels alone. Complete survival of bone after successful revascularization of the posterior type of graft is well established but this graft has the disadvantage of a complicated dorsal dissection which has limited its clinical use. Many microsurgeons have utilized the posterolateral rib segment, which is easy and safe to excise although its viability and adequate microcirculation are not confirmed. In 9 large dogs the viability and vascularity of bone after transfer of the 2 types of bone grafts was compared by histological methods, fluorochrome bone labeling, microangiography and Tc scintigraphy. The grafts were transferred to the subcutaneous fat tissue in the groin, where blood supply was reconstituted by microvascular anastomoses to local donor vessels. A bone transplant with revascularization of periosteal vessels only established a collateral circulation to medullary vessels. There is no difference in viability of the 2 kinds of grafts.