Bone Pathology Of Skeletal Development

Front 1

What is generalized skeletal disease?

Back 1

affects appendicular and axial skeleton equally
*may be diffuse, multifocal, cortical, medullary etc.

Front 2

What is localized skeletal disease?

Back 2

affects primarily the appendicular OR axial skeleton (unequal)

Front 3

What patterns can be seen with localized skeletal disease?

Back 3

symmetrical or asymmetrical
bone or cartilage

Front 4

What are the features of primordial dwarfism?

Back 4

skeleton and soft tissues perfectly formed but small
proportionate head, limbs, trunk
limbs are straight

Front 5

Give an example of primordial dwarfism

Back 5

miniature breeds of animals

Front 6

What is achondroplastic dwarfism?

Back 6

inherited defect of the cartilage model causing a reduction in interstitial growth of the physes

Front 7

What parts of the bone are affected in an achondroplastic dwarf?

Back 7

metaphysis of long bones and basicranial bones

Front 8

What are the gross features of achondroplastic dwarfism?

Back 8

long bones are short, paired bones (eg: radius and ulna) are bowed, bone diameter is too thick for the length, maxilla fails to grow rostrally (brachycephaly and domed skull), vertebral bodies are short and thick

Front 9

What do the growth plates of an achondroplastic dwarf look like histologically?

Back 9

normal (can't see rate of growth on a slide)

Front 10

What is pituitary dwarfism?

Back 10

failure to form a complete, functional pituitary gland

Front 11

How does pituitary dwarfism cause problems?

Back 11

lack of GH, affects rate of interstitial cartilage growth

Front 12

What breed is commonly affected by pituitary dwarfism?

Back 12

German Shepherd (still rare)

Front 13

What are the features of pituitary dwarfism?

Back 13

multiple endocrine deficiencies
small but proportionate skeleton
delayed physeal closure (4 yrs of age)
retention of puppy hair coat
generalized skin disease
failure to develop permanent teeth
infantile genitalia

Front 14

What is a solitary osteochondroma?

Back 14

cartilage capped exostosis on the surface of an endochondral bone

Front 15

Where are osteochondromas found?

Back 15

near growth plates

Front 16

What is the significance of osteochondromas?

Back 16

generally don't cause problems but may interfere with tendon or joint movement depending on location

Front 17

What is the difference between single osteochondroma and osteochondromatosis?

Back 17

Osteochondromatosis is more than one osteochondroma and is a genetic, transmissible disorder. These dogs should NOT be bred.

Front 18

What are chondrodystrophoid breeds of dog?

Back 18

inbred achondroplastic dwarves, resulting in a stable population (breed) with these characteristics

Front 19

What problems do chondrodystrophoid breeds have with the skeleton?

Back 19

predisposed to DJD
predisposed to IV disc disease at an early age

Front 20

What is epiphyseal dysplasia?

Back 20

disease of the epiphyses with multiple foci of mineralization and poor formation

Front 21

What problems does epiphyseal dysplasia cause?

Back 21

delayed walking
predisposition to DJD

Front 22

What is metaphyseal dysplasia?

Back 22

cartilage core retention of the distal ulna

Front 23

What animals are affected by metaphyseal dysplasia and what deformations are seen?

Back 23

large/giant breed dogs
often bilateral delayed longitudinal growth of the ulna, resulting in valgus deformity

Front 24

What is osteogenesis imperfecta? What does it produce?

Back 24

polygenetic defect of osteoblasts, odontoblasts and fibroblasts
produces abnormal Type I collagen

Front 25

What are the effects of osteogenesis imperfecta?

Back 25

pathologic fractures
osteopenic skeleton
joint laxity
pink teeth
blue sclera

Front 26

What animals are affected with osteogenesis imperfecta?

Back 26

dogs, calves, sheep, cats

Front 27

What is osteopetrosis?

Back 27

autosomal recessive, lethal disorder of osteoclast failure

Front 28

What is the effect of osteopetrosis?

Back 28

defective modeling and remodeling of bone
cortices are thick
little to no medullary cavity
no cutback zones
dense thickened skull plates

Front 29

What is canine panosteitis?

Back 29

self limiting painful disease of young dogs
lesions occur in medullary cavity

Front 30

What breed is affected most commonly with canine panosteitis?

Back 30

German Shepherd Dogs

Front 31

What is the result of canine panosteitis?

Back 31

inconsistent development of low density bone in the medullary cavity (starting at nutrient foramen, working inward)
usually regresses on its own

Front 32

What is hypertrophic osteodystrophy?

Back 32

symmetrical bone lesions at the metaphyseal physes of long bones (and others)

Front 33

What animals are most commonly affected with hypertrophic osteodystrophy?

Back 33

young, male large and giant breed dogs

Front 34

What are the two types of hypertrophic osteodystrophy?

Back 34

associated with chronic overnutrition
idiopathic

Front 35

What problems are associated with HOD-like chronic overnutrition?

Back 35

increased bone density
no destruction of primary cancellous bone
*reversible by limiting food intake

Front 36

What problems are associated with idiopathic HOD?

Back 36

systemic illness (fever, anorexia, reluctance to walk)
*may die, or have sequelae such as bowed limbs, valgus deformity, mandibular enlargement

Front 37

What are the histologic and radiographic changes seen with HOD?

Back 37

necrotic metaphyseal capillaries and bone forming mesenchyme
necrosis, fragmentation and lysis of primary bony trabeculae
double growth plate on radiograph
extraperiosteal bony cuff formation
congestion and edema of surrounding soft tissue

Front 38

What is craniomandibular osteopathy?

Back 38

"lion's jaw"
non-infectious proliferative bone disease of the mandible, occipital and temporal bones, tympanic bullae

Front 39

What animals are most commonly affected by craniomandibular osteopathy?

Back 39

3-6 month olds
Westies, Scotties, Cairn Terriers, Boston Terriers
rarely Labs, Great Danes, Boxers, Dobermans

Front 40

What is the effect of craniomandibular osteopathy?

Back 40

bilaterally symmetrical proliferation
symptoms from mild discomfort to inability to open the mouth to eat or drink

Front 41

What is the prognosis for craniomandibular osteopathy?

Back 41

recovery in mild cases
fibrosis and fusion may occur
*proliferation ceases at skeletal maturity, some regression may occur