Bone remodeling and Repair

Factors

• Diet

• Exercise

• Hormone function

• Sun exposure

What is an osteoblast

The bone cells that store calcium and make up our bones

Osteoclast

The bone cells that break down bone tissue and releases stored calcium

What are the 4 stages of healing a bone fracture

1. Hematoma Formation

2. Fibrocartilage Callus Formation

3. Bony Callus formation

4. Bone remodeling

Hematoma formation- step 1

• Blood vessels that are ruptured during the break swell to form a mass called a hematoma.

• This mass forms between the broken bones.

Fibrocartilage Callus formation- step 2

• New capillaries form within the clotted blood in the damaged area.

• Connective tissue cells form a mass of repair tissue called a fibrocartilage callus.

• This callus contains some cartilage, some bone and collagen fibers and the combined mass closes the gap between the broken bones.

Bony Callus formation- step 3

• The fibrocartilage callus is replaced by one made of spongy bone.

• This new mass is referred to as the bony callus.

• Osteoclasts and osteoblasts move to the area and multiply.

What are the osteoclasts and osteoblasts job in step 3?

Osteoclast breaks down stored Clacium →

Osteoclast rebuilds fracture

Bone Remodeling- step 4

• During healing timeframe, the callus is remodeled with the help of osteoclasts and osteoblasts.

• The shape of the bones gradually return to normal and there will eventually be little evidence of the fracture. 

What are the osteoclasts and osteoblasts job in step 4?

When bone heals, Osteoclasts remove extra calcium from callus →

Osteoblasts stores calcium for future usage

Put the steps in order:

Fibrocartilage Callus Formation

Bone remodeling

Hematoma Formation

Bony Callus Formation

1. Hematoma Formation

2. Fibrocartilage Callus Formation

3. Bony Callus Formation

4. Bone remodeling