Ch 7 Bones - General

Question 1

Name the zones:

Answer 1

Resting
Proliferative
Maturation
Hypertrophy
Calcification
Vascular

Question 2

What is the normal direction of the nutrient foramens, and which bone is the exception?

Answer 2

A clearly defined channel may be seen running at an angle through the cortex, usually from the periosteal surface proximally to the endosteal surface distally (although this direction is reversed in the ulna).

Question 3

The cortex is made of ________ bone.

Answer 3

compact

Question 4

The metaphysis / epiphysis is made of ________ bone.

Answer 4

cancellous

Question 5

What is the term for the secondary centre of ossification (starred)?

Answer 5

Apophysis; additional non-articular cartilaginous protuberances that ossify and form sites of attachment for tendons and ligaments.

Question 6

In the immature long bone, the physis is essentially vascular / avascular.

Answer 6

Avascular.

Question 7

Where does the blood supply originate for the epiphysis?

Answer 7

Joint capsule

Question 8

Where does the blood supply originate for the metaphysis?

Answer 8

nutrient foramen

Question 9

Which portion of the long bone is hypervascular, making it the preferred location for e.g. hematogenous osteomyelitis?

Answer 9

metaphysis

Question 10

What is the cutback zone?

Answer 10

Irregular bone appearance in the metaphyses of growing bones due to modelling by active subperiosteal osteoclastic activity

Question 11

Which condition is bone infarction associated in dogs, and which in cats?

Answer 11

canine osteosarcoma (or other primary bone malignancy)
feline leukemia

Question 12

Name the types of periosteal reactions

Answer 12

Question 13

What are the names of these 2 types of lytic changes and which is more aggressive?

Answer 13

Permeative is more aggressive than moth-eaten.

Question 14

Which type of lysis is affecting the distal 4th metatarsal bone?

Answer 14

Geographic; note the cortical thinning and expansion.

Question 15

What are 3 typical causes of a solid periosteal reaction?

Answer 15

Fracture callous
chronic osteomyelitis
panosteitis

Question 16

Which is more aggressive - thin brush (spiculated) or thick brush (palisading) periosteal reaction?

Answer 16

Thin brush; The periosteum is lifted with osteoblastic activity along Sharpey’s fibers. If it is less aggressive and slower growing, the spicules are thicker. The thinner the reaction, the more aggressive the process because there is less time for new bone production.

Question 17

What is the most likely origin of a sunburst periosteal reaction? what about amorphous bone production?

Answer 17

osteosarcoma
also osteosarcoma

Question 18

Answer 18

Proximal tibial
osteosarcoma with amorphous bone
formation seen lateral to the proximal fibula. A solid periosteal reaction (Codman’s triangle, arrowed) is present on the lateral cortex of the proximal tibial diaphysis.

Question 19

Answer 19

Osteosarcoma of the frontal bone with a sunburst periosteal reaction.

Question 20

Answer 20

Thin brush-like
periosteal reaction of the abaxial
surface of metatarsals II andVinacaseof hypertrophic osteopathy.

Question 21

Answer 21

Thick brush-like
periosteal reaction on the abaxial
surface of metacarpal V in a dog with hypertrophic osteopathy.

Question 22

Answer 22

Focal soft tissue swelling and lamellar periosteal reaction cranially on the radius. Radiograph deliberately underexposed.

Question 23

What are the terms for these 2 types of changes?

Answer 23

Question 24

What kind of pathology results in endosteal scalloping?

Answer 24

intramedullary neoplasia

Question 25

What kind of pathology results in subperiosteal scalloping?

Answer 25

hematogenous osteomyelitis