Regenerative medicine Flashcards
tissue repair
where remodelling replaces damage tissue
forms inferior tissue (scar)
tissue regeneration
where we expect remodelling to restore native tissue
no scar
what does the liver and bone have in common
both have the ability to regenerate
what is special about bone
if injured in anyway it will try to repair by forming new bone
why do fractures unite
because the bone is broken
cells in the bone
osteocytes
osteoblasts
osteoclasts
2 components of extracellular matrix
organic,35%
inorganic, 65%
organic components of the extracellular matrix
type 1 collagen
osteocalcin
osteonectin
proteoglycans
glycosaminoglycans
ground substance
inorganic components of extracellular matrix
hydroxyapatite
what is in the image
cortical bone
what is in the image
cancellous bone
prerequisites for bone healing
adequate blood supply
adequate mechanical stability
blood supply to diaphyseal bone
nutrient artery
metaphyseal vessels
periosteal vessels
nutrient artery
intramedullary
supplies inner 2/3 of cortex
metaphyseal vessels
rich supply from soft tissue
periosteal vessels
supplies outer 1/3
label the blood supply of the bone
what are the 2 mechanisms of bone healing
direct/primary
indirect/secondary
primary bone healing
no motion at the fracture site
no callus formation
secondary bone healing
motion at the fracture site
callus formation
direct bone healing
no motion or callus
rigid internal fixation
osteoblast form cutting cones across the fracture site
osteoblasts lay down lamellar bone behind
osteons form late
slow process
indirect healing
unstable
callus stabilises
direct healing between cortices
stages of the healing cascade
inflammation, 0-5 days
repair,5-42 days
late repair
regeneration and remodelling
inflammation
haematoma
necrotic material
phagocytosis
repair
granulation tissue
acid environment
periosteum, osteogenic cells
cortical osteoclasis
late repair
fibrous tissue replaced by cartilage
endochondral ossification
periostea healing»_space; membranous ossification
regeneration and remodelling
replacement of callus (woven bone with lamellar bone)
continued osteoclasis
mechanical strain
what is articular cartilage
65-80% water
type 2 collagen
proteoglycans
chondrocytes
matrix components
what is in the image
articular cartilage
what does the classic healing response require
site specific cells for phagocytosis and tissue synthesis
vascular supply
what does the classic healing response require
site specific cells for phagocytosis and tissue synthesis
vascular supply
3 phase response
phagocytosis
inflammatory
remodelling
limitation of articular cartilage
chondrocytes imprisoned in a mesh of collagen and proteoglycans
avascular nature of cartilage
treatment options
surgical treatment options
marrow stimulation techniques
osteochondral autograft transfer
osteochondral allograft transfer
autologous chondrocyte implantation
marrow stimulation techniques
abrasion arthroplasty
subchondral drilling
micro fracture
why do chondral lesions not heal
need blood supply
need site specific cells for phagocytosis
osteochondral autograft transfer
mosaicplasty
lavage and debridement beneficial for
low energy trauma
mechanical symptoms
minimal malalignment
stable ligaments
low BMI
short term 50-70% benefit
micro fracture in 1959
drilling generates heat
incomplete debridement
what is in the image
micro fracture
autologous chondrocyte implanttion
biopsy
implantation
criteria in deciding treatment
what occurs after treatment
synthetics
scaffolds
minced cartilage techniques
2nd and 3rd generation cell based
synthetic meniscus
