BONE REMODELING AND REPAIR

Question 1

Order the three stresses from needing the most amount of stress applied to needing the least amount of stress applied:

1. Tension (Stretch)
2. Shear (Twist)
3. Compression

Answer 1

1. Compression
2. Tension
3. Shear

Question 2

What is compact fracture of humerus?

Answer 2

The radial nerve is cut (breaks at a 45 degree angle = shearing twist)

Question 3

What are the six steps of bone remodeling and repair?

Answer 3

1. After the fracture, extensive bleeding occurs leading to a large blood clot (fracture hematoma) to develop
2. An internal callus forms as a network of spongy bone unites the inner edges, and an external callus of cartilage and bone stabilties the outer edges
3. The cartilage of the external callus has been replaced by bone, and structs of spongy bone now unite the broken ends.
4. Fragments of dead bone and the areas of bone closest to the break have been removed and replaced
5. A swelling initially marks the location of the fracture
6. Over time, this region will be remodeled and little evidence of the fracture will remain

Question 4

What is the difference between normal and osteoporotic bone?

Answer 4

• Normal bone takes more stress to strain (good) therefore bone is in good shape
• Osteoporotic bone takes less stress to strain (bad) therefore bone loss occurs overtime