Small Animal Ortho: Bone Healing Flashcards
What are the factors that affect bone healing?
Age of animal
location of fracture
presence of necrotic debris
vascularity
stability
distance b/w fragments
degree of immobilization
fracture type
degree of post reduction opposition
degree of local trauma
degree of bone loss
type of bone involved
How does infection affect fracture healing?
will slow/retard the healing process
How does local malignancy affect fracture healing?
they heal slower than normal but can still heal
How do corticosteroids affect fracture healing?
inhibit healing
the inhibit the differentiation of osteoblasts from mesenchymal cells and decrease the rate of synthesis of major components of the bone matrix
How does the fracture being stable vs. unstable affect callus formation?
if stable and gap small vessels & osteoblasts directly cross gap & deposit= minimal callus
if unstable and gap large, vessels cross gap will be torn & callus will be large
What are the 2 ways that fractures can heal?
Stable and unstable conditions
What are stable fracture conditions?
direct opposition of bone
results in direct/primary bone healing
What are unstable fracture conditions?
connective tissue, fibrocartilage then bone
results in indirect or secondary bone healing
What are the 4 stages of fracture healing?
Coagulation
Inflammation
Granulation
Maturation
What is the coagulation step of bone healing?
hematoma forms at fracture gap
What is the inflammation step of bone healing?
neutrophils, macrophages, osteoclasts gather @ fracture site to clean it up
What is the granulation step of bone healing?
callus forms by:
fibroblasts producing fibrous tissue
chondrocytes produce fibrocartilage
osteoblasts produce bone
What is the maturation step of bone healing?
remodeling
modeling
osteoclast/osteoblasts
What is indirect/secondary bone healing?
occurs through the formation of a callus & subsequent remodeling
What type of bone is involved in indirect/secondary bone healing and what is it?
Woven bone: characterized by a haphazard organization of collagen fibers & is mechanically weak
When is indirect/secondary bone healing preferred?
Good blood supply
large gaps > 1mm
not rigidly stable
What is direct/primary bone healing?
reestablishment of the cortex w/o the formation of a callus
What type of bone is involved in direct/primary bone healing and what is it?
lamellar bone: characterized by a regular parallel alignment of collagen into sheets & is mechanically strong
When is direct/primary bone healing preferred?
Little to no gaps (less that 1mm)
good blood supply
stable conditions
What is fracture assessment scoring?
method of selecting appropriate repair technique by considering 3 factors. The higher the score the more factors that favor wound healing
What are the 3 factors to consider in fracture scoring?
Mechanical: fracture factors
Biological: patient factors
Clinical: owner factors pain tolerance of P
What occurs in areas < 200 micrometers apart?
hematoma gap
little remodeling
blood vessels & mesenchymal cell
osteoblasts deposit lamellar bone
What occurs in areas > 200 micrometers but < 1 mm
hematoma gap
later remodeling
blood vessels & mesenchymal cell
osteoblasts deposit woven bone haphazardly
