DKK1-Ab increases bone volume and mechanical strength of fracture callus. Micro-CT and mechanical testing were performed on bone samples derived from mice treated with DKK1-Ab or Vehicle at 7, 10, 14 and 21 days after fracture. Micro-CT analysis showed that bone volume and BV/TV were increased in callus tissues 10, 14 and 21 days after fracture in the mice treated with DKK1-Ab. Mechanical testing showed that maximal torque and stiffness were increased by DKK1-Ab treatment 14, 21 and 28 days after fracture. Data are presented as means ± SD. *p < 0.05, one-way ANOVA followed by Tukey’s test, n = 6.