14. bone graft Flashcards
explain the different mechanisms of bone healing
EO- endochondral ossification, cartilage template, found in long bones
IO-intramembranous ossification - flat bones, skull
cutting cones- makes the canaliculi- occurs in primary fracture/bone healing and remodeling
examine different types and functions of bone grafts
demonstate clinical assessment of bone healing
osteoblast
produce
derived from
turn into
produce osteoid
MSC
turn into osteocytes once trapped in lacunae
osteoclast
derived from
activity is painful
resorb/destroy bone
hematopoietic stem cell
enzymatic breakdown of osteoid
multinucleated cells
primary vs secondary osteon form
osteon- found in cortical bone/lamelar bone
primary- during primary bone growth/development
osteoblast laying down osteoid
secondary-during remodeling- cutting cones, osteoclastic resorption activity
cutting cones
osteoclast resorbing bone and osteoblast following behind
occurs during primary bone repair/healing and remodeling
IO- intramembranous ossification
this increase the width of the bone
found in flat bones, inner and outlayer of long bones (periosteum/endosteum)
osteoblast differentiate from progenitor cell and lay down osteoid- do not need cartilage template
IO increases the ___ of bone
EO increases the ___ of bone
IO- width
EO- the length
EO- endochondral ossification
its a cartilage precursor
chondrocyte-zone of hypertrophy -calcification
increases LENGTH of bone
prerequisites for bone healing
-rigid stabilization ( <2% strain)
-blood supply
-no infection
goals of stabilization
decrease interfragmentary strain
decrease fracture gap
direct bone healing/primary bone healing
< 1mm gap
cutting cones
no callus forms
needs rigid stability
secondary osteon
indirect healing/secondary
will form a callus
both EO and IO
less stable, callus helps stabilize a fracture
inflammation–>callus–>remodeling
osteogenesis
osteoblast in bone material contribute to new bone growth
osteoinduction
bone graft recruits osteoprogenitor cells and induced the formation of new bone
osteoconduction
bone graft serves as a scaffold for osteoprogenitor cells
synthetic bone grafts are osteoconductive
osteopromotion
enhances osteoinduction production without osteoinduction properties
bone graft indications
speed healing, promote healing of infected areas and non-union
enhances healing and helps with bone loss
autograft
graft from self
allograft
graft some another animal
xenograft
graft from a different species
types of bone grafts
cancellous/spongy/trabecular bone
cortical/lamellar bone
corticocancellous
mineralized bone matrix
synthetic bone graft
cancellous bone graft
autogenous is the GOLD standard
osteogenesis-osteoblast comes
osteoinductive - recruits progenitor cells
osteoconductive- scaffold for osteoprogenitor cells
cortical bone graft
mechanical support
osteoconductive- scaffold for osteoprogenitor cells
harvesting cancellous bone graft
aseptic
prepare surgical site in advance
drill hole, collect cancellous bone
cancellous donor sites for large animal
ilium
sternum
cancellous donor site for small animal
