摘要INTRODUCTIONEndochondral ossification is the process by which long bones form during development, and it is the most common process by which adult bones heal.1–3 Most cortical bone fracture healing occurs via the initial formation of a fibrocartilaginous (soft) callus that is filled with proliferating chondrocytes;at later stages, these proliferating chondrocytes terminally differentiate into hyper-trophic chondrocytes and secrete extracellular matrix compo-nents, including type I and type 10 collagen, that mediate the gradual mineralization of the soft callus and hardening of the fracture gap.1–3 This facilitates the invasion of new blood vessels and subsequent replacement of chondrocytes with newly formed woven bone via the endochondral ossification process.1–3