Current Concepts of Bone Healing

Bone injuries induce an inflammatory response that promotes bone healing. On the other hand, an aberrant process, where inflammation becomes chronic, can inhibit the healing of injured bone. At the first stage of the bone healing process, inflammatory cells, such as neutrophils and macrophages, are assembled and secrete various cytokines, chemokines, and growth factors. During callus formation, cells differentiated from mesenchymal stem cells, such as osteoblasts and chondrocytes, play leading roles in bone healing. Currently, various treatment modalities have been developed through the known mechanism of bone healing, and the clinical outcomes of bone defect and fracture nonunion have been good.