how does broken bone heal when the bone is broken that's called fracture the fracture goes through different stages to achieve healing it is a stage of hematoma from the fracture followed by a stage of inflammation followed by a stage of soft callus followed by hard callus followed by remodeling when the fracture occurs there will be bleeding at the fraction site and this will make a fibrin blood clot the stage of hematoma is followed by the stage of inflammation there'll be a lot of cells microphages and mesenchymal stem cells the stem cells migrate to the fracture and form the granulation tissue and releases growth factors that helps in healing the fracture and that helps in uniting the fracture together cox-2 Inhibitors and non-esteroidal depresses run X2 which is important for differentiation of the osteoblast the stage of inflammation is followed by the stage of soft callus soft callus will occur within two weeks the amount of callus correlates with immobilization the stiffer the immobilization the less amount of callus flexible fixation will result in endochondral ossification abundant callus what is secondary bone healing and what is primary bone healing secondary bone healing is healing through cartilage formation lack of stability helps the formation of cartilage which later on can change the endocondral ossification in primary bone healing you will find absolute stability and it's called have version remodeling cutting cone remodeling or intramembranous healing that occurs when the fixation is rigid and when the bone is fixed with plates secondary bone healing will occur when the fixation is not rigid such as with the cast or intermedullary rod and there will be endocardial ossification some cartilage type 2 collagen in primary bone healing will be type 1 collagen bone is formed first before cartilage then the bone takes number one collagen and the cartilage takes number two collagen stage of hard callus hard callus the collagen changes from type 2 to type 1. then the last stage is a stage of remodeling the stage of remodeling begins early and continues many years after the fracture has healed the woven bone will be replaced by a stronger laminar bone and the fracture healing will be complete with the continuation of the medullary canal the remodeling of the bone is influenced by the wolf's law that means that the bone is affected by stress so you start by stage of hematoma inflammation soft callus heart callus remodeling in this order thank you very much I hope that was helpful