This is a descriptive manuscript reporting variations of a technique named Endosteal Allograft Plating, which is an evolution of the Endosteal Substitution concept. The described allograft substitution method provides the advantage of a biologic substitute in areas of marked bone loss, and yields structural integrity to provide a rigid fixed angle, in an attempt to decrease healing times and prevent fixation failure. The technique includes placement of an intramedullary allograft strut in the area of bone loss. A conventional plate is utilized on the exterior bone surface, and screws are directed through the native and allograft bone. The allograft strut is first fixed in compression to the native bone. Iliac crest autograft is used to supplement the allograft. Five variations on intramedullary strut design are defined for different circumstances. These named variations of the Endosteal Substitution technique include: Endosteal Plating, Endosteal Allograft Plating, Endosteal Allograft Distraction, Endosteal Allograft Suspension, Endosteal Allograft Suspension Arthrodesis and Endosteal Allograft Inlay. Recalcitrant bone nonunions pose a challenging treatment problem. Such nonunions are associated with multiple operative interventions and significant disability, and frequently with significant bone loss, infection, hardware failure and severe osteopenia. Innovative techniques have been described to address such situations. The biologic buttress provided by the endosteal allograft plate has proved to be a useful solution in the treatment of recalcitrant nonunions and long bone defects.