The adjunctive role of demineralized bone matrix (DBM) in enhancing the incorporation of segmentai freeze dried (FD)-allogeneic bone grafts has been studied in the rabbit ulna and fibula. The studies compared the healing patterns of fresh segmentai autografts, FD-allografts, DBM-allografts, and FD-allografts supplemented at the graft-host junctions with FD- or DBM-allografts as particulars (ulna) or as segmentai struts (fibula). The outcome was evaluated at five and ten weeks by a radiologie score, by biomechanical properties (breaking strength, energy to failure, stiffness), and histology. The ulnar autografts healed most rapidly (ten weeks = 100%), followed by DBM allografts (60%). By all criteria, FD-allografts were poorly incorporated (20–40%), and the process was not improved by supplements of FD- or DBM-particulate/strut bone. Histologically, the DBM component of composite fibular strut grafts was osteoinductive and united with host tissues within 35 days. The contiguous FD-allograft struts were not incorporated, showing fibrocartilaginous nonunions and resorptive foci. While the addition of DBM does not protect FD-allograft integrity in the rabbit, segmentai mineralized FD-allografts could provide mechanical support for some intervals until, in such composite grafts, osteoinductive processes produced biomechanically competent new bone.