During the fracture, a bone will first produce a hematoma, which is the extravasation of blood that has been the vessels that are inside the bone, that is, in the medullary areas.
Then to this there will be areas of debris and necrosis that will be reabsorbed by macrophages, in this way the clot that is formed by a grading tissue that is richly nutritious with contact cells to differentiate itself from osteoblasts and other cell phones will be replaced.
It is here where these cells as they are immature cells automatically differentiated to bone cells are called as osteogenic cells, that is why they acquire bone powers and differentiate themselves from a specialized tissue that would be bone tissue.
Following the formation of granulation tissue, the presence of osteoblasts that differentiate and manufacture osteoids will appear.
The osteoid is a poorly calcified immature extracellular matrix that forms the osteblast so that it calcifies and thus the mature bone tissue is formed, once this osteoid calcifies the steoblasts are submerged in calcification and mature into osteocytes thus forming the functional unit of the bone tissue that is called havers systems or havers systems (it is the summation of mature or calcified osteoid plus a mature osteocyte central to calcification).
This calcification is done in a disorderly way and with the collagen fibers in a reticular position, that is why this calcification is called as immature callus and is not capable of withstanding forces or stresses but the calcification process is already complete.
Over time, this immature or premature bone callus is reabsorbed by the osteoclast and simultaneously replaced by the most ordered ostebolast, that is, this time the callus is calcified with the collagen fibers in a parallel and linear way depending on the forces It will support the bone tissue, so the mature bone callus is prepared to form tensions, thus being the last step of bone healing.
Explanation:
There are concepts that should be clarified before all this explanation:
The main one is that the bone tissue has different cell types, the 3 most pathognomonic cells of this tissue are the osteoclast (reabsorption function), osteoblast (function of synthesis) and osteocyte (mature osteoblast immersed in the calcified bone trabeculae)
On the other hand, I mentioned above that osteoclasts reabsorb bone tissue, that is to say in simple words "degrade" it, while the osteblast on the other hand synthesized it, this process in bone is called bone remodeling and occurs throughout our lives in order to rebuild the properties of the tissues, that is, it is a constant "replacement" of the bone tissue since we are not born with the same bone or femur with which we die.
So the bone remodeling process DOES NOT CHANGE THE SHAPE OF THE BONE, BUT RENEWS IT, how is this achieved in the body? Easy, while the osteoclast reabsorbs in one area of the bone, the osteblast synthesizes simultaneously in the opposite pole in a synchronized way to maintain the morphology and structure of each bone of our organism.
The bone remodeling process is DIFFERENT FROM BONE MODELING, bone modeling would be the design of our bones in the fetal or embryonic stage, and it occurs once in a lifetime, that is why in bone healing it is wrong to say that there is a presence of bone modeling, the correct word would be BODY REMODELING.
