Repair of Broken Bones

REPAIR OF BROKEN BONES

The bones are much strong. But still it can break. There are following reasons of fractures:

➤ Trauma causes most of fractures during youth. These  trauma may be sports injuries, automobile accidents, falls etc. These fractures may twist or break the bones.

➤ In old age, bones become thin and weak. Thus fractures can occur more frequently.

Treatment of fracture:

Following steps takes place during treatment of a fracture:

1. Reduction:

A fracture is treated by reduction. There are two types of reduction: closed and open reduction.

➤ Closed reduction:

In this case, the broken ends of the bone are coaxed back to their normal position by physician's hand.

➤ Open reduction:

In this case, surgery is performed and the bone ends are brought together with pins or wires.

2. Realignment:

Then realignment of the broken end is done.

3. Healing:

After broken bone is reduced, it is immobilized  by a cast  or by traction. It starts the healing process.

Healing time is 8-12 weeks. But it is much longer for longer or weight bearing bones and for bones of elderly people (because of their poorer blood circulation). 

Phases of repair process:

The repair process of a simple fracture takes place in four phases:

1. Hematoma Formation :

The blood vessels in the bone or in its surrounding areas are torn when a bone breaks. It causes hemorrhage. As a result, a hematoma is formed at the fracture site. Hematoma is a mass of. clotted blood. Therefore, blood can not be supplied to some cells. Such cells start dying. Thus the tissue at the fracture site becomes swollen and painful.

2. Callus Formation :

"Soft callus" start forming in 3-4 weeks. Capillaries grow into the hematoma and clear up the debris. Fibroblasts and osteoblasts migrate into the fracture site. They start the construction of the bone.

3. Bony Callus Formation :

Osteoblasts and osteoclasts continue to migrate inward. They multiply rapidly and gradually convert the soft callus into bony callus. Bone formation begins 3-4 weeks after injury. It remains continue until a firm bony union is formed within 2-3 months later.

4. Remodeling:

After several months bony callus is remodeled by the excess material on the outside of the bone. Final structure of remodeled area resembles that of the original unbroken bone. Now. this bone responds to the same set of mechanical stimuli.

MUSCLES

Many multicellular animals have specialized cells for movement. These cells contain numerous filaments. These filaments have special protein called actin and myosin. The vertebrate possess three kinds of muscle cells. Smoot muscles, skeletal muscles and cardiac muscles.

1. Smooth Muscles:

They have following characteristics:

1. Smooth muscles are visceral muscles. They are present in viscera organs like stomach, intestine and blood vessels and many other organs.

2. They are non-striated muscles.

3. Smooth muscles are the earliest form of muscle.

4. They are found throughout the animal kingdom.

5. Smooth muscles are long and spindle shape. Each cell contains a single nucleus. These have no striations.

6. These are involuntary muscles.

2. Cardiac Muscles:

The muscles of heart are called cardiac muscles. They constitute most of the mass of the heart walls. Heart muscle is composed of chains of single cell. Each cell has its own nucleus. The chains of cells åre organized into fibers. These fibers are branched and interconnected. These are striated and involuntary muscles.

3. Skeletal Muscles:

The muscles attached with the skeleton and associated with the movement of bones are called skeletal muscles. The skeletal muscles are consciously. controlled. Therefore, they are called voluntary muscles. Skeletal muscles show alternate light and dark bands. So they are also called striped or striated muscle. e. g. triceps and biceps. Generally each end of entire muscle is attached to bone by tendon: The bundle of collagen, non-elastic fibers by which muscles are attached with the bones are known as tendons.