Robbins 9th ed - Chapter 26 - Bones, Joints - Fractures (1)

Question 1

What is the very first step in fracture repair, occurring immediately after fracture?

Answer 1

Rupture of blood vessels causes haematoma formation, which fills the fracture gap. The clot provides a fibrin mesh, sealing off the fracture site, and providing a framework for the influx of inflammatory cells (neutrophils).

Question 2

By the end of the first week after fracture, there is formation of a _______ at the fracture site. Describe this.

Answer 2

Procallus (or “soft tissue callus”). Procallus involves hyaline cartilage, matrix production, and soft tissue anchorage between the ends of the fractured bones, but not enough structural rigidity for weight-bearing.

Question 3

After approximately _____ weeks after a fracture, there is bony callus formation.

Answer 3

Two.

Question 4

The newly formed cartilage along the fracture line undergoes __________ ossification.

Answer 4

Endochondral.

Question 5

The bony callus reaches its maximal girth by which week?

Answer 5

Third week.

Question 6

Which type of bone matrix is produced first, and which type develops later after fracture? Lamellar or Woven?

Answer 6

Woven bone is produced first, and is eventually replaced by Lamellar bone.