how dose a bone repair itself?

Answer 1

In the process of fracture healing, several phases of recovery facilitate the proliferation and protection of the areas surrounding fractures and dislocations.

Basically:

Days after fracture, the cells of the periosteum replicate and transform. The periosteal cells proximal to the fracture gap develop into chondroblasts and form hyaline cartilage. The periosteal cells distal to the fracture gap develop into osteoblasts and form woven bone. The fibroblasts within the granulation tissue also develop into chondroblasts and form hyaline cartilage. These two new tissues grow in size until they unite with their counterparts from other pieces of the fracture. This process forms the fracture callus. Eventually, the fracture gap is bridged by the hyaline cartilage and woven bone, restoring some of its original strength.

The next phase is the replacement of the hyaline cartilage and woven bone with "lamellar bone". The replacement process is known as "endochondral ossification" with respect to the hyaline cartilage and "bony substitution" with respect to the woven bone. Substitution of the woven bone with lamellar bone precedes the substitution of the hyaline cartilage with lamellar bone. The lamellar bone begins forming soon after the collagen matrix of either tissue becomes mineralized. At this point, "vascular channels" with many accompanying osteoblasts penetrate the mineralized matrix. The osteoblasts form new lamellar bone upon the recently exposed surface of the mineralized matrix. This new lamellar bone is in the form of "trabecular bone". Eventually, all of the woven bone and cartilage of the original fracture callus is replaced by trabeclular bone, restoring much, if not all, of the bone's original strength.

Answer 2

In the process of fracture healing, several phases of recovery facilitate the proliferation and protection of the areas surrounding fractures and dislocations. The length of the process is relevant to the extent of the injury, and usual margins of two to three weeks are given for the reparation of the majority of upper bodily fractures; anywhere above four weeks given for lower bodily injury.

for more detail you can read here

http://en.wikipedia.org/wiki/Bone_healing

Answer 3

it makes fibers to hold it in place, then it fills in making new bone, takes a few months. In seven years the bone is good as new.

Answer 4

It grafts its self together