How does a fractured bone heal?

Bones are among the strongest structures in the body, but a simple fall can break them. So our amazing bones have an amazing ability - to self-repair. Here's how.

Although bone tissue is four times stronger than concrete, breaks are so common that most people don't even think of it as a severe injury (though it can be).

Once a patient with a fractured bone arrives to the hospital, an X-ray is taken, and a doctor identifies the location of the fractures. Subsequently, the fractures are placed in the correct anatomical position, ensuring that as little new tissue as possible must be generated to reunite the fractures and that the healing takes place in the correct fashion.

Finally, the fractures must be held safely in position, until the bones have healed. That is often done by a plaster cast or orthosis, which provide support and ease the pain, as the fractures cannot move and harm surrounding tissue and nerves. In complex cases, it is necessary to fixate the fractures by means of metal wire, nails, or screws, which requires surgery.

According to a rule of thumb, it takes twice as long for a fracture to heal in the bottom half of the body (16 weeks) as in the top half (8 weeks).

In children, fractures heal twice as quickly, whereas in elderly people, it will typically take longer.

BONES NEED RESISTANCE

Bones break down and regenerate themselves, when they are subjected to a load. In the 1800s, German anatomist Julius Wolff discovered that bones become stronger, the more load they are subjected to. And they erode and become porous, when there is no load – like with astronauts in a state of weightlessness.