Disorders of the Physis

Question 1

what are the parts of long bones?

Answer 1

epiphysis
physis
metaphysis
diaphysis

Question 2

what is the epiphysis?

Answer 2

end of a long bone
secondary center of ossification

Question 3

what are the two cartilagenous areas of long bones?

Answer 3

articular cartilage
physeal cartilage

Question 4

what size and shape is physeal cartilage?

Answer 4

size and shape of diaphysis

Question 5

how does longitudinal bone growth occur?

Answer 5

endochondral ossification

Question 6

what is the reserve zone adjacent to?

Answer 6

epiphysis

Question 7

what does the proliferative zone look like?

Answer 7

cells divide in a linear fashion

Question 8

where are germinal cells?

Answer 8

adjacent to epiphysis

Question 9

what do the cells look like in the hypertrophic zone?

Answer 9

broad, flat cells

Question 10

what happens in the calcification zone?

Answer 10

matrix seeded with calcium phosphate
hydroxyappetite crystals form and calcify

Question 11

what arteries supply the physeal blood supply?

Answer 11

epiphyseal artery
metaphyseal artery

Question 12

what does disruptions of epiphyseal blood supply lead to?

Answer 12

necrosis of germinal cells and permanent cessation of growth

Question 13

what does disruption of the metaphyseal blood supply result in?

Answer 13

reversible cessation of ossification

Question 14

the cartilaginous physis is ___________ than the adjacent bone

Answer 14

weaker

Question 15

what does salter-harris classification classify physeal fractures based on?

Answer 15

anatomic location and correlated with prognosis

Question 16

what is a type VI fracture?

Answer 16

traumatically induced periosteal bridging resulting in an angular or rotational deformity

Question 17

what does the salter-harris classification not take into account?

Answer 17

age of animal
specific bone involved or location

Question 18

what does a salter-harris type I spare?

Answer 18

reserve zone of cartilage cells

Question 19

what is a salter-harris type I?

Answer 19

fracture or separation through the hypertrophic zone

Question 20

what is a salter-harris type II?

Answer 20

fracture or separation through portion of hypertrophic zone and the metaphysis

Question 21

what is a salter-harris type III?

Answer 21

fracture or separation through a portion of the hypertrophic zone and the epiphysis

Question 22

what is a salter-harris type IV?

Answer 22

fracture or separation through a portion of the hypertrophic zone, metaphysis, and epiphysis

Question 23

what is a salter-harris type V?

Answer 23

crushing injury of the physis

Question 24

what does a salter-harris type V result in?

Answer 24

necrosis of resting layer of cartilage cells and therefore cessation of bone growth

Question 25

what is the most common site of a salter-harris type VI (not truly salter-harris)?

Answer 25

distal radius

Question 26

where are retained cartilaginous cores most common?

Answer 26

distal ulnar physis and metaphysis

Question 27

what does a retained cartilaginous core cause?

Answer 27

slowed growth of distal ulnar physis

Question 28

who are angular limb deformities in horses most common in?

Answer 28

young foals

Question 29

what is angular limb deformity in foals?

Answer 29

deviation from the normal axis in the frontal plane

Question 30

what are some causes of angular limb deformity in young foals?

Answer 30

premature birth twins placentitis trauma soft tissue laxity crushing of non-ossified cuboidal bones

Question 31

what is the metaphysis of a long bone?

Answer 31

wider tapered section between epiphysis and diaphysis

Question 32

what does the hypertrophic zone look like?

Answer 32

broad, flat cells 8x increase cell volume decrease in extracellular matrix

Question 33

where does a stress riser exist?

Answer 33

within the hypertrophic zone

Question 34

where does a fracture occur with an overload applied to the physis?

Answer 34

hypertrophic zone due to stress concentration at this level

Question 35

what does salter-harris not take into account?

Answer 35

age of animal specific bone involved or location

Question 36

what is the most common site of a salter-harris type II fracture?

Answer 36

distal femur

Question 37

what is the most common site of a salter-harris type IV fracture?

Answer 37

distal humerus

Question 38

what is the most common site of a salter-harris type V fracture?

Answer 38

distal ulna

Question 39

what are some causes of angular limb deformity in older foals?

Answer 39

nutritional imbalance excessive exercise trauma growth plate injury

Question 40

what is the most common site for a salter-harris type I?

Answer 40

femoral capital physis

Question 41

what is the most common site of a salter-harris "type VI"?

Answer 41

distal radius