Musculoskeletal Growth and Repair

Question 1

Diaphysis

Answer 1

Shaft of the bone

Question 2

Metaphysis

Answer 2

the flare at the end of the shaft

Question 3

Epiphysis

Answer 3

Joint on the side of the physis

Question 4

Medullary Canal

Answer 4

Central cavity of bone shafts where red bone marrow and yellow bone marrow is stored, hence, the medullary cavity is known as the marrow cavity

Question 5

Cortical bone

Answer 5

Dense form of bone which is found in the diaphysis. Its function is to resist bending and torsion. It is laid down circumferentially and is less biologically active.

Question 6

Cancellous Bone

Answer 6

This is trabecular or spongey bone which is found in the metaphysis. It absorbs compression, is the site of longitudinal growth and is very biologically active.

Question 7

Define a fracture

Answer 7

A break in the structural continuity of bone

Question 8

State the possible reasons as to why a fracture may occur

Answer 8

High energy transfer, repetitive stress, or low energy transfers in abnormal bones

Question 9

State stage 1 of fractures

Answer 9

Inflammation

Question 10

When does inflammation begin

Answer 10

Immediately after the fracture

Question 11

What occurs during inflammation after a fracture

Answer 11

There is a haematoma and fibrin clots form. There is the accumulation of platelets, PMN’s, neutrophils, monocytes, macrophages and fibroblasts, mesenchymal and osteoprogenitor cells. All of this results in osteogenic induction off cells from muscle and soft tissue

Question 12

What are mesenchymal and osteoprogenitor cells

Answer 12

Transformed endothelial cells from the medullary canal and or periosteum

Question 13

Why does angiogenesis occur during the inflammation stage

Answer 13

Macrophages produce angiogenic factors under hypoxic conditions

Question 14

What can increase the amount of blood loss in a fracture

Answer 14

NSAID’s, open fractures and extensive tissue damage

Question 15

What is stage 2 of fracture repair

Answer 15

Soft callus

Question 16

When does soft callus occur

Answer 16

When the pain and swelling subside and lasts until bony fragments are united by cartilage or fibrous tissue

Question 17

What can be given to patients to help with initial healing of bones (inflammation)

Answer 17

Platelet concentrates including platelet-derived growth factor, vascular endothelial growth factor, TGF-B, insulin-like growth factor

Question 18

State the different treatment methods used during soft callus stage

Answer 18

DMB (demineralised bone matrix), bone graft, bone substitutes, autogenous cancellous bone graft, or allograft bone

Question 19

State stage three of fracture healing

Answer 19

Hard callus.

Question 20

What is hard callus

Answer 20

This is the conversion of cartilage to woven bone. There is increasing rigidity and obvious callus.

Question 21

State stage 4 of fracture healing

Answer 21

Bone remodelling, this is the conversion of woven bone to lamellar bone. The medullary canal is also reconstituted

Question 22

Delayed union

Answer 22

The failure of the fracture to heal in the expected time

Question 23

State the reasons why delayed union may occur

Answer 23

• High energy injury
• Distraction
• Instability
• Infection
• Steroids
• Immune Suppressants
• Smoking
• Warfarin
• NSAID
• Ciprofloxacin

Question 24

Non-union

Answer 24

This is the failure of the fracture to heal completely

Question 25

State the reasons in which non-union can occur

Answer 25

• Failure calcification fibrocartilage
• Instability – excessive osteoclasis
• Abundant callus formation
• Pain and tenderness
• Persistent fracture line
• Sclerosis