TPO was used to promote the growth of bone in both rats and in mice. Gaps in both mouse and in rat bones were treated with a scaffold sized to fit the gap. Scaffolds that included TPO promoted better outcomes than scaffolds that included BMP-2 or scaffolds that did not include either TPO or BMP-2. These data indicate that compounds that exhibit thrombopoietic activity such a recombinant TPO can be used to promote bone growth and healing in mammals.