1) The document discusses complications that can occur during the healing of cutaneous wounds, including deficient scar formation, incisional hernias, hypertrophic scarring, keloid formation, excessive contraction and granulation. 2) It also examines healing in specialized tissues like bone, gastrointestinal tract, nervous system, liver, kidney and muscle. Bone healing involves procallus formation, osseous callus formation and remodeling. Fracture healing complications include fibrous union, non-union and delayed union. 3) Gastrointestinal tract healing depends on the depth of injury, from mucosal erosions and ulcerations to replacement by scar tissue in deeper injuries. Nervous system healing involves gliosis

1. Healing and repair - 2
Dr H.M.D.Moratuwagama
Dept of Pathology

2. Complications of cutaneous wound healing

3. 1)Deficient scar formation
Wound dehiscence / ulceration

4. 2.Incisional Hernia
I

5. 3.a)Hypertrophic scar

6. 3.b)Keloid

7. •What is the difference between a hypertrophic
scar and a keloid?

8. Hypertrophic scar is raised,
erythematous, and remains within
the boundaries of the original
trauma or wound.
A keloid, on the other hand,
extends beyond the confines of the
wound and is more nodular.

9. 3.c)Exuberant granulation

10. 4)Excessive contraction
Formation of contractures

11. 5.Implantation cyst

12. 6.Marjolin's ulcer

13. Complications of cutaneous wound
healing
1)Deficient scar formation
• Wound dehiscence / ulceration
2) Incisional hernia
3)Formation of excessive amount of repair component
a)Hypertrophic scar
b)Keloid formation
c)Exuberant granulation
4)Excessive contraction
Formation of contractures
5) Implantation cyst
6) Rarely – neoplasia may develop
Squamous cell carcinoma following burns

14. Healing in specialized tissue
1.Bone
2.GIT
3.Nervous system
4.Liver
5.Kidney
6.Muscle

15. Healing in specialized tissue
Fracture healing
1)Procallous formation
2)Osseous callous formation
3) Remodeling

16. Fracture healing cont.
1) Procalus formation
• Haematoma forms at the site of fracture
• Fibrin clot forms the framework
• Local inflammatory response- PMN ,
macrophages
• In growth of granulation tissue
• Callus formed of woven bone forms
( fusiform shape)

18. Fracture healing cont.
2)Osseous callus formation
• On the procallus lamellar bone forms
• Woven bone cleared by osteoclasts
3) Remodeling
• Osteoclasts clear the excess bone
• Osteoblasts lay down bone
• External callus
- Cleared away
• Intemediate callus - Compact bone forms ( cortex)
• Internal callus
- Bone marrow forms

21. Complications of fracture healing
1) Fibrous union
• Usually when immobilization is not done
• False joints may also form (Pseudoarthrosis)
2)Non –union
• In the presence of soft tissue between the
fracture ends
3)Delayed union

22. Gastrointestinal tract
• Depends on the depth of injury
1)Mucosal erosions
• Viable epithelium proliferate and fill the
defect

23. 2)Mucosal ulceration
• Defect covered by blood
• Macrophage remove debris
• Granulation tissue form
• Mucosa spread from the margin to the base of
the ulcer
• Muscle replaced by scar tissue
• May lead to stenosis and obstruction

24. Nervous system
Central nervous system
• Nerve cells of the CNS , spinal cord and ganglia
are permanent cells
• Only glial cells proliferate – Gliosis

25. Nervous system cont.
Peripheral nerves
- Wallerian degeneration
• With transection of nerve fibres the axon and the
myelin sheath undergo degeneration upto the
closest proximal node of Ranvier
• Disintegrated fibres are phagocytosed
• Regeneration occurs with sprouting of axons
and proliferation of schwann cells from the
proximal ends

27. LIVER
• Hepatocytes have a
high regenerative
capacity
• Injury leads to
complete restitution of
the tissue
• However if connective
tissue network is
severely damaged
fibrosis occur
The eagle Ethon eating each day a part of the liver of Prometheus

28. Kidney
• Tubular cell damage with intact BM
• Tubular epithelial cells regenerate
• Glomerular damage
scaring

29. Muscle
Cardiac muscle
• Permanent cells
• Replaced by scar tissue
Smooth muscle
• Limited regenerative capacity
• With larger injury
Skeletal muscle
• Intact muscle sheath
Damaged muscle sheath
scar tissue form
Properly oriented
muscle form
Fibrous scar

30. The healing of an injured skeletal muscle usually follows a constant pattern
1.Destruction phase-the rupture and ensuing necrosis of the myofibres,
formation of a haematoma between the ruptured muscle stumps, and
inflammatory cell reaction.
2.Repair phase - phagocytosis of the necrotised tissue, regeneration of
the myofibres, and concomitant production of a connective tissue scar, as well
as capillary in growth into the injured area.
3.Remodelling phase-regenerated myofibres mature, the scar tissue
contracts and is re-organised, and the functional capacity of the muscle
recovers
.

31. Summary
• The process by which healing occurs in a tissue
is dependant on several factors
– Type of cell , extent of injury etc
• Depending on the type of wounds, healing
process follows two pathways
- Healing by primary intension
- Healing by second intension
• There are systemic and local factors that may
delay wound healing
• Healing in other specialized tissue also depends
on the type of tissue and the extent of injury