After baseline testing, WT and SP KO (Tac1−/−
) mice underwent a right distal tibia fracture (FX) and the hindlimb was casted for 3 weeks (black bar on x-axis), then the cast was removed and the animals were retested at 3, 4, 6, 8, 10, 12, 15, and 18 weeks post fracture (n = 7 per cohort). The methods for testing and calculating the graph values are described in Figure 2. (A) Hindpaw allodynia was present at 3 weeks in both groups and resolved by 18 weeks post-fracture in the WT mice and by 6 weeks post-fracture in the SP KO cohort. When compared at the same post-fracture time points the magnitude of allodynia was consistently less in the SP KO mice than that observed in the WT mice. (B) Hindpaw unweighting was present at 3 weeks after fracture in both groups and resolved by 10 weeks in the WT mice and by 8 weeks the SP KO mice, but the magnitude of unweighting was consistently less in the SP KO mice than the WT. Hindpaw warmth (C) and edema (D) were present at 3 weeks post-fracture in the WT mice and resolved by 8 weeks post-fracture for warmth and 6 weeks for edema. Hindpaw warmth and edema was not observed in the SP KO mice at any time point. *P < 0.05, **P < 0.01, and ***P < 0.001 vs WT FX mice at the same time point.