 Let's talk about fracture repair. So a fracture is going to be a crack or a break in a bone caused by physical stress. They can be either too much stress on a healthy bone or you could have a normal amount of stress on weak bone, I guess, but there's a fracture. Now what are we going to do about it? So first you see that what happens first is blood vessels show up, bleeding occurs and this produces what's called a fracture hematoma which establishes kind of a fibrous network and just it's going to try to stabilize the area as best as it can. This takes a few hours. The bone cells in this area are actually going to die. Then we go on to be there. The cells of the endosteum, the skin on the inside of your bone and the periosteum, the skin on the outside of your bone are going to actually divide and migrate into this fracture zone. They're going to become cells that make new bone for you and they're going to form these calluses. So the external callus is going to be like a collar or a cuff of cartilage and bone on the outside and then the same thing is going to happen on the inside, this internal callus. So you're trying to stabilize this bone as quickly as possible. So an internal callus is going to develop there in the center in the marrow cavity, external callus on the outside. Notice that callus is actually enlarged on the edges which is why you can often tell where there's been a fracture even though remodeling will get rid of most of that in the future. Then we have, so we go into C, osteoblast are going to come in, they're going to remove all the cartilage or replace all that cartilage with bone, but notice that it's spongy bone. So we started with a fracture hematoma, a blood clot. Then these calluses, now we have spongy bone being laid down, then over time osteoblasts and osteocytes are going to come in, they're going to remodel and they're going to turn this spongy bone into compact bone and the fracture is going to be healed. Now if you're healthy and everything goes well, a fracture should be at least as strong as it used to be if not stronger unlike bone's cousin cartilage which because it's a vascular and doesn't normally grow in adults, cartilage repair is very poor if existent at all. Alright so that's going to be how a fracture is repaired, a pretty straightforward process. I hope this helps, have a wonderful day, be blessed.