Bone grafts are of three types--autogenous (from the same individual), homogenous (from the same species), and heterogenous (from a different species). They have many uses--to bridge joints and provide arthrodesis; to fill defects resulting from an osteotomy, excision of a tumor, or a loss of bone: and to provide bone blocks and promote union. The most important single factor in the success of a bone graft is the response and vitality of the host bed, and the most favorable conditions for survival of transplants are autogenous transfers to a well prepared host bed.