14. bone graft

Question 1

explain the different mechanisms of bone healing

Answer 1

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

Question 2

examine different types and functions of bone grafts

Question 3

demonstate clinical assessment of bone healing

Question 4

osteoblast
produce
derived from
turn into

Answer 4

produce osteoid
MSC
turn into osteocytes once trapped in lacunae

Question 5

osteoclast
derived from

Answer 5

activity is painful
resorb/destroy bone
hematopoietic stem cell
enzymatic breakdown of osteoid
multinucleated cells

Question 6

primary vs secondary osteon form

Answer 6

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

Question 7

cutting cones

Answer 7

osteoclast resorbing bone and osteoblast following behind
occurs during primary bone repair/healing and remodeling

Question 8

IO- intramembranous ossification

this increase the width of the bone

Answer 8

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

Question 9

IO increases the ___ of bone
EO increases the ___ of bone

Answer 9

IO- width
EO- the length

Question 10

EO- endochondral ossification

Answer 10

its a cartilage precursor

chondrocyte-zone of hypertrophy -calcification

increases LENGTH of bone

Question 11

prerequisites for bone healing

Answer 11

-rigid stabilization ( <2% strain)
-blood supply
-no infection

Question 12

goals of stabilization

Answer 12

decrease interfragmentary strain

decrease fracture gap

Question 13

direct bone healing/primary bone healing

Answer 13

< 1mm gap
cutting cones
no callus forms
needs rigid stability
secondary osteon

Question 14

indirect healing/secondary

Answer 14

will form a callus
both EO and IO
less stable, callus helps stabilize a fracture
inflammation–>callus–>remodeling

Question 15

osteogenesis

Answer 15

osteoblast in bone material contribute to new bone growth

Question 16

osteoinduction

Answer 16

bone graft recruits osteoprogenitor cells and induced the formation of new bone

Question 17

osteoconduction

Answer 17

bone graft serves as a scaffold for osteoprogenitor cells

synthetic bone grafts are osteoconductive

Question 18

osteopromotion

Answer 18

enhances osteoinduction production without osteoinduction properties

Question 19

bone graft indications

Answer 19

speed healing, promote healing of infected areas and non-union

enhances healing and helps with bone loss

Question 20

autograft

Answer 20

graft from self

Question 21

allograft

Answer 21

graft some another animal

Question 22

xenograft

Answer 22

graft from a different species

Question 23

types of bone grafts

Answer 23

cancellous/spongy/trabecular bone

cortical/lamellar bone

corticocancellous

mineralized bone matrix

synthetic bone graft

Question 24

cancellous bone graft

Answer 24

autogenous is the GOLD standard

osteogenesis-osteoblast comes
osteoinductive - recruits progenitor cells
osteoconductive- scaffold for osteoprogenitor cells

Question 25

cortical bone graft

Answer 25

mechanical support

osteoconductive- scaffold for osteoprogenitor cells

Question 26

harvesting cancellous bone graft

Answer 26

aseptic
prepare surgical site in advance
drill hole, collect cancellous bone

Question 27

cancellous donor sites for large animal

Answer 27

ilium
sternum

Question 28

cancellous donor site for small animal