A) Representative microCT images of bone formation in the defect region at 12 weeks. MicroCT data were analyzed to specifically assess new bone within the 4 mm defect site across implant replicates, and to obtain quantitative measures of B) total bone volume, C) mineral content, D) mineral density, and E) bone volume fraction (bone volume/tissue volume). F) Histology images of newly formed bone in the defect site using Movat’s pentachrome staining. (Collagen fibers = yellow; fibrin = bright red; nuclei = purple-black). G) Blood vessel area within the defect was quantified from H) histology images, which showed well-developed vessels containing erythrocytes throughout the volume of OD-MSC microtissue implants.