Fracture healing

Question 1

What type of bone has a slow turnover rate?

Answer 1

Cortical/compact bone

Question 2

what does it mean if a bone has a high young’s modulus?

Answer 2

it is resistant to torsion (twisting) and bending

Question 3

What type of bone has a High turnover rate/undergoes greater remodelling?

Answer 3

Trabecular bone

Question 4

what does it mean if a bone has a low young’s modulus?

Answer 4

It is more elastic and turns easily

Question 5

What are the two types of fracture healing and which one occurs most often?

Answer 5

Primary (Direct healing) - occurs less often

Secondary (indirect healing) - normally occurs

Question 6

Define primary/direct fracture healing

Answer 6

Direct formation of bone, without the process of callus formation, to restore skeletal continuity

Question 7

Define secondary/indirect fracture healing

Answer 7

Formation of bone via a process of differential tissue formation until skeletal continuity is restored.

Question 8

Describe the process of primary fracture healing (what is it, when does it occur, how is the fracture, what does it rely on?)

Answer 8

It is a unique, ‘artificial’ surgical situation (created by surgeons to promote bone healing)
Occurs when there is rotational malalignment of bone.
Fracture is stable (no movement under physiological load).
Relies upon compression of bone ends
Direct formation of bone via Osteoclast absorption and osteoblastic formation. (cutting cones)

Question 9

What portions of the bone does the endosteal blood supply ?

Answer 9

inner 2/3

Question 10

What portions of the bone does the periosteal blood supply ?

Answer 10

Outer 1/3

Question 11

What 2 factors can be responsible for compromise fo blood supply to bone?

Answer 11

Surgical factors (damage blood supply during surgery)
Anatomical factors

Question 12

List 4 fractures that can cause blood supply problems

Answer 12

Intracapsular hip fracture
Surgical neck of humerus fracture
Talar neck fracture
Proximal pole of scaphoid fractures