Transcript Lecture 7 The Injury Process

The Injury Process of
Healing
Lecture 8
Soft Tissue
everything but bone
 - 3 phases
 Involves a complex series of interrelated
physical and chemical activities
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Inflammatory Phase
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First event is the actual injury – tissue undergoes some
sort of trauma , (can be mechanical , chemical , thermal
or infectious agent)
Immediate – disruption of tissue – bleeding as a result
of vascular structures – namely the capillaries – fluids
from damages cells may leak out to the interstitial space
(space between the cells)
The body responds with vasoconstriction in an attempt
to decrease the bleeding – this usually lasts a few
minutes
Followed by vasodilation
Blood vessels are often damaged , as a
result there is an increase in blood flow to
the interstitial spaces ( space between
cells)
 This results in a hematoma ( or a localized
collection of blood) being formed
 A hematoma can develop quickly because
blood flow can increase as much as 10
times.
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Five signs of inflammation?
 Swelling
 Pain
 Redness
 Warmth
 Loss of function
Swelling
2) Proliferative (Repair)
Phase
Second stage in the healing process
 Body is replacing damaged or dead cells
with new cells
 healing - 3 days to 6-8 weeks
 Repair process can occur in three ways
, and often all three are occurring to
some degree at the injured site

Resolution
Dead cellular material and debris are
removed ( process of phagocytosis)
 In this case the tissue has suffered
minimal damage and is left with its
original architecture intact
 Cells grow and return to their pre injured
state
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Granulation (fibroplasia)
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Fibroplasia allows the lost tissue to be replaced
with fibrous scar produced from granulation
tissue
The purpose of the scar is to form a bridge
between portions of the tissue that became
separated or torn ( the larger the gap the larger
the scar)
Scar tissue often lack the vascularity ,
neurological feedback and the strength of the
original tissue.
Regeneration
the replacement of tissue by the same
tissue (restoration of destroyed or lost
tissue)
 Dead or damaged cells are replaced by
new cells
 These cells are the same type not scar
tissue
 Factors that effect our ability to regenerate
are , age , nutritional status amount of
tissue lost and local blood supply
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Primary role of therapist during repair phase is
to assist the involved structures in gaining
strength
Collagen fibres must align along the lines of
tensile force , and increase in number and size
in response to the appropriate stresses, such as
movement and weight bearing and
strengthening exercises
Must be done with out too much stress as to
cause re injury
Any new inflammation will delay total healing
process, as well as returning to full activity
Maturation (remodeling)Phase
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Third and final stage , this phase can last a year or more
, but generally peeks around 8 – 12 weeks
This phase is typically not complete before returning to
full activity
involves maturation of newly formed tissue, decreased
fibroblast activity, increased organization of extracellullar
matrix and return to normal histochemical activity
over lapping tissue repair and remodelling
A definitive scar is formed and tensile strength increases
in response to applied stresses
Blood flow returns to normal
Factors that Impede healing
Local infection
 Embedded foreign objects
 Inadequate blood supply
 Corticosteriods
 Nutritional deficiencies ( vit c , zinc and
protein)
 General well being (health issues /
diabetes)
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MUSCLE
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Muscle is quite different from that if
ligaments , tendons and joint capsules
Muscles have excellent blood supply , this
increases the muscle tissue’s capacity for
healing
If blood vessels torn then healing may not be
as good , pooled blood seen as bruising
Ability to return to full function is affected by
the size of the tear and the subsequent scar
formation
Scar tissue is non contractile , stiff and can
form adhesions , which may limit movement
and function in an otherwise healthy muscle.
Nerves
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Nerves are thought to heal more slowly
than all other tissues
When a nerve becomes torn , edges
must physically touch for healing to occur
If gap becomes filled with scar tissue ,
the electrical impulses cannot be
transmitted , and the scar is permanent
road block
If healing is successful it is slow because
of the poor blood supply