Healing

Question 0

[Wound healing] Phase II is also known as…

Answer 0

Substrate or Lag phase (Inflammatory phase)

Question 1

Stages of wound healing and timeframes (5)

Answer 1

1. Epithelialization (within few hrs after wounding)
2. Inflammatory (wounding to 3-5/7)
3. Fibroplasia (4-5/7 to 14-28/7)
4. Scar maturation/remodelling (14-28/7 to several years)
5. Contraction (4-5/7 to 21/7)

Question 2

[Wound healing] Phase III is also known as…

Answer 2

Latent phase (Fibroplasia)

Question 3

[Wound healing] Phase 1 includes… (3)

Answer 3

Epithelialization
A. Regeneration of epithelial layer
- Mobilization
- Migration
- Proliferation
- Differentiation

B. Cover exposed dermis
C. May be complete 6-48/24 after wounding

Question 4

[Wound healing] Phase II includes…

Answer 4

Inflammatory
A. Vascular response (5-10min vasoCONSTRICT then vasoDILATION)

B. Phagocytosis (neutrophils/macrophages –> bacteria/debris)

Question 5

[Wound healing] Phase III includes…

Answer 5

Fibroplasia
A. Fibroblasts enter + synth collagen
–> B. Tensile strength increased

C. Angiogenesis (capillary budding begins)
D. Formulation of granulation tissue (new collagen/capillaries)
— will be red

Question 6

[Wound healing] Phase IV includes…

Answer 6

Scar maturation/remodelling
A. Strength increased (intra/intermolecular cross-linking of collagen)
B. Collagen changes (bulk, form, architecture - more organised with stress)
C. Scar from red, raised —> pale, flat

Question 7

[Wound healing] Phase V includes…

Answer 7

Contraction
A. Wound margins towards centre
B. Myofibroblasts thought to be responsible

Question 8

What are myofibroblasts?

Answer 8

Modified fibroblasts

Question 9

Really general stages of wound healing, and do they overlap?

Answer 9

Inflammatory
Proliferative
Maturation

And yes.

Question 10

Phases and timing of fracture healing (3)

Answer 10

1. Inflammatory (# to 3-4/7)
2. Reparative (to 4-6/52)
3. Remodelling phase (first few months to several years)

Question 11

[Fracture healing] Describe phase 1 (3 actions and 2 results)

Answer 11

Inflammatory

• gap in bone bridged by clot
• –> coagulates to form haematoma
• inflammatory response triggered by mediators (released from dead/damaged cells)
• –> vasodilation, plasma exudation, inflam cells migrate to site
• Osteoclasts resorb, fibroblasts start new matrix

Question 12

[Fracture healing] Describe phase 2 (general - 3)

Answer 12

Reparative
[Hematoma organisation]
- fibrin framework, fibroblasts and mesenchymal cells (undifferentiated)
- capillary budding
- cells to # callus

Question 13

What is the centre of the inflammatory reaction made up of, and called? What phase?

Answer 13

Cartilage
Called soft callus
Reparative phase

Question 14

Describe the hard callus

Answer 14

• Immature bone

- At periphery of soft callus reaction

Question 15

When is the # considered clinically healed? What signs would be present?

Answer 15

End of reparative phase

• No motion at #-site when stressed
• No pain with AROM of nearby jts
• Little radiographic evidence of # healing

Question 16

What percentage of time does it take for clinical healing, compared to complete bony healing?

Answer 16

25% of the time

Question 17

[Fracture healing] Describe phase 3

Answer 17

Remodelling

• Lamellar bone replaces woven bone
• Callus resorbed

Question 18

What is primary bone healing, i.e. ORIF?

Answer 18

Ends brought into direct contact with one another

Question 19

Describe the phases of primary bone healing (2) and what happens (3)

Answer 19

Gap healing
Haversian remodelling

1. Lamellar bone across #-site
2. OCs bridge #-line
3. OBs, then new capillaries, follow OCs
   - –> new haversian systems (primary osteons)