Due to the limitations associated with autograft, researchers are pursuing the use of bone-graft substitutes to promote arthrodesis. Bone-graft substitutes now being used by surgeons include ceramic synthetics, bone morphogenic proteins (BMPs), demineralized bone matrices (DBMs) and other allografts; these may be used alone or in combination. Allografts available as substitutes for autograft offer some of the benefits of autograft without its limitations—but do not contain viable MSCs and OPCs.