At 3 weeks after tibia fracture the wildtype (WT) and substance P deficient (SP KO, Tac−/−
) mice were euthanized and the femurs ipsilateral to the fracture were collected for uCT evaluation. No difference was observed in distal femur trabecular bone volumes of WT and SP KO unfractured control mice (A), but there was a dramatic post-fracture reduction in distal femur bone volume in both strains of mice relative to their respective unfractured controls (n = 10 per cohort). There was no difference in the magnitude of post-fracture trabecular bone loss between WT and SP deficient mice. Fracture also caused a slight reduction in midfemur cortical bone area in both the WT and SP KO mice (B). There were no differences between the WT and SP KO in either baseline or post-fracture midfemur relative cortical areas. ###P < 0.001 vs respective unfractured controls.