Skeletal modelling Flashcards
When does osteogenesis occur during pregnancy?
Week 5
describe osteogenesis
Hyaline cartilage, prechondrium becomes periosteum. Then bone modelling occurs in response to dynamic strain
Wolff law
forms follows function: skeletal architecture adopts to its history of mechanical usage. static stress ( splint) does not cause bone transformation
does dynamic stress cause bone transformation? give an example.
yes. long bones are thickest at mid shaft. curve bones are thickest at where they are most llikely to buckle. large bony attachments from wheere heavily active mm’s attach
internal structure of bones hollowed out compare to edges
Endochondral ossificaiton
ossification chases cartilage formation?
what is metaphysis
Transition zone where it is going from cartilage to bone
what is epiphysis
the epiphysis is a hyaline cartilage and it forms and has the same rate of ossification
describe the tension force modeling effect
an increase in distance between 2 points, drawing 2 sites away from the centre
E.g tendon and ligaments
creaates raises ridges such as trachanter and tuberosities
Describe the compression modelling effect?
-reduction between the distance between the end of an object
it will lead to an inc in bone diameter
needs to obe dynamic and increase the bone growth at the site of appilication . E.g weight bearing and GRF.
describe the Flexure force modeling effect?
Requires 3 points of pressure. Forced applied to the end of already curved bones. The results are further curving. E.g. wb on an already bowed or highly cartilagineous
Describe the shear-torsion force
forces applied in the opposite direction
Results in torsion of the axis of long bones with both ends rotating in the opposite direction to each other
Characteristics of young bone
-articular cartilage is thicker and can remodel
-vulnerable growth plate
-apophyses is a vulerable site-avulsion
Metaphysis= elastic (bend rather than break)
where fracture is likely to occur in young children
metaphyseal, physeal and avulsion, Growth plate, distal tibial epiphysis, 1st year, anything cause growth disturbance and rapid growth
what is salter harris classification?
Type 1: physis fracture
Type 2: metaphysis and physis fracture
Type 3: epiphysis and physis fracture
Type 4: Epiphysis to metaphysis fracture
Type 5: Crush fracture
Fibrous tissue types
3 types of fibrous tissue
1- Fascial sheets
2-ligmanets or tendons
3- Loose 3D network
