FIG. 1.

Stages of bone healing upon fracture/injury, which can be divided in five main steps: inflammation, intramembranous ossification, chondrogenesis, endochondral ossification, and remodeling. In more detail, after injury (i), bone undergoes an induction stage where there is an influx of inflammatory cells and occurs the formation of hematoma, as shown in (ii). Gray areas represent necrotic bone tissue. Afterward, during inflammation, occurs the formation of a cartilage intermediate, as it can be observed by the gray area in (iii). Stage (iv) represents the formation of the soft callus, in which a chondrogenic matrix unites the defect area. From this moment, ossification occurs and woven bone replaces the temporary cartilaginous template through the invasion of blood vessels (stage (v)) and finally, remodeling occurs in step (vi) with lamellar bone promoting the union of the defects and the medullar cavity being restored. Adapted from refs.^68,69 Color images available online at www.liebertpub.com/teb