Thrall chapter 18 Orthopaedic disease of young and growing dogs and cats

Question 1

1) Osteochondrosis occurs most commonly at what site in dogs?
a) Cranial aspect of the proximal humeral head
b) Caudal aspect of the proximal humeral head
c) Distomedial aspect of the humeral trochlea
d) Femoral condyles

Answer 1

B

Question 2

3) At what age should the anconeal process be fused to the ulna by?
a) 150 days
b) 160 days
c) 170 days
d) 180 days

Answer 2

a. it is not always a separate centre of ossification.

Question 3

4) Congenital radial head luxation has been reported in which breeds? (can be more than one)
a) Pug
b) Shih tzu
c) Bulldogs
d) Pekingnese

what direction does it luxate?

Answer 3

b (chondrodystrophic dogs),c

caudolateral luxation usually

Question 4

5) Which of the following is false regarding osteogenesis imperfecta?
a) It is a heritable disease caused by a structural defect in type 1 collagen
b) It affects the bones only
c) Radiographically it can be confused with secondary hyperparathyroidism
d) The teeth may appear pink

Answer 4

b

Question 5

6) Which disease(s) below involve disruption of normal endochondral ossification?
a) Rickets
b) Osteopetrosis
c) Multiple cartilaginous exostosis
d) Retained cartilage core

Answer 5

c, d

Question 6

7) Retained cartilage cores usually occur in which animals and bones?
a) Small breed dogs, distal radius
b) Brachycephalic dogs, lateral femoral condyle
c) Large breed dogs, distal ulna metaphysis
d) Cats, distal ulna metaphysis

Answer 6

c

Question 7

what are the two predilections sites of OC/ OCD in the humerus

Answer 7

caudal aspect of the humeral head and distomedial humeral trochlea

Question 8

a distraction index more than XX is predictive of the development of degenerative joint changes in GSDs with hip dysplasia
a) 0.15
b) 0.2
c) 0.3
d) 0.55

Answer 8

C

Question 9

a distraction index more than XX is predictive of the development of degenerative joint changes in Labrador retrievers with hip dysplasia
a) 0.15
b) 0.3
c) 0.4
d) 0.55

Answer 9

C also rottweilers

Question 10

which of the following is not found in congenital hypothyroidism?
a) disproportionate dwarfism
b) delayed ossification of the diaphyses
c) delayed ossification of the epiphyses
d) delayed ossification of the cuboid bones

Answer 10

B
Vertebral bodies are shorter than normal as a result of endplate dysplasia. The skull may appear shorter and broader than normal. Degenerative joint disease may be seen as a sequel.

Question 11

what diseases should be considered in this 5 month old dog with stunted growth, lameness and bilateral symmetrical radiographic findings seen in the image below (3)?

Answer 11

MPS- urine test variable phenotypic presentation
congenital hypothyroidism- blood test, disproportionate dwarfism (constipation?)
multiple epiphyseal dysplasia- disease of exclusion. stunted growth

Question 12

Which regions of bones/ bones are affected in multiple epiphyseal dysplasia?

Answer 12

epiphyses
apophyses
cuboidal bones
sesamoids

The disease is characterized by failure of ossification of the epiphyses, apophyses, cuboidal bones, and sesamoids. stippling of the epiphyses and irregular epiphyseal margins. Affected epiphyses eventually mineralize but are moderately deformed. Aberrant separate centers of ossification that eventually fuse with the normal ossification centers have also been described. Accelerated degenerative joint disease occurs.

similar features to MPS and congenital hypothyroidism

Question 13

which feature is not seen in MPS?
a) coxofemoral luxation/ subluxation
b) aneurysmal dilation of the aorta
c) small epiphyses with a granular opacity
d) cuboidal vertebral bodies
e) osteopenia
f) spontaneous physeal fractures
g) degenerative joint disease

Answer 13

F

many features and very variable appearance

Question 14

the medial and lateral portion of the humeral condyle should fuse by approximately … after birth
a) 22 days
b) 84 days
c) 110 days
d) 150 days

Answer 14

B

Question 15

in cases of incomplete ossification of the humeral condyle, which is the most common fracture configuration?
a) Y/ T
b) medial epicondylar and condylar fracture
c) lateral epicondylar and condylar fracture
d) distal humeral diaphyseal and condylar fracture

Answer 15

A then C

Question 16

what disease is this?
what causes it (3)?

Answer 16

rickets
dietary deficiency in vit d- can then also have issues absorbing calcium and get secondary hyperparathyroidism

or heritable disorders- type I (unable to convert vit d to active form)) and type II (resistance to vit d due to faulty receptors)

Question 17

describe the imaging features of rickets

Answer 17

widening of the physes creating large, nonmineralized gaps with flaring and cupping of the adjacent epiphyses and metaphyses
Flared osteochondral junctions along the ribs
Diffuse osteopenia with thin cortices may be appreciated and can progress to folding fractures.

Question 18

a dog presents with short-limbed disproportionate dwarfism, you take radiographs and the physes are wide, the carpal bones are subjectively small and the metaphysis are flared. the skull and vertebrae seem relatively normal. what breed is this and what disease?
a) Labrador retriever
b) Norwegian elkhound
c) Alaskan malamute
d) osteochondrodysplasia
e) chondrodysplasia
f) rickets

Answer 18

C, E

Question 19

which disease is autosomal dominant
a) Chondrodysplasia of Alaskan malamutes
b) osteochondrodysplasia of Scottish fold cats
c) Chondrodysplasia of Norwegian elkhounds
d) ocular chondrodysplasia of labradors

Answer 19

B

Question 20

Answer 20

Scottish fold osteochondrodysplasia

Question 21

Answer 21

osteochrondromatosis/ multiple cartilaginous exostosis

Question 22

what is the difference between osteochrondromatosis/ multiple cartilaginous exostosis in cats compared to dogs?

Answer 22

in cats they typically develop in young adults and progressively enlarge throughout life. in dogs they stop growing when the dog stops growing

Question 23

what is the clinical significance of this lesion?

Answer 23

Cartilage retention may cause angular limb deformity from retardation of distal ulnar growth and a resulting mismatch in radial and ulnar elongation, but the lesion is sometimes an incidental finding in otherwise normal dogs

Question 24

Answer 24

there is more diffuse increased medullary opacity in the ulna, which is typical of a later stage of the disease. C, Panosteitis in an 8-month-old canine mix. There is increased medullary opacity in the mid-diaphysis of the humerus at the level of the nutrient foramen, although the foramen is not visible in this dog. Canine panosteitis often begins at the level of the nutrient foramen. There is a focal region of smooth periosteal reaction (black arrow) on the caudal aspect of the humerus.

Question 25

Answer 25

Canine panosteitis in a 6-month-old German shepherd. There is a diffuse increase in medullary opacity in the humerus and an extensive periosteal reaction on the caudal aspect of the humerus. Smooth, continuous periosteal new bone formation develops in the diaphysis of affected bones in one-third to one-half of dogs. Late in the disease, opacities resolve, leaving coarse, thickened trabecular bone that eventually assumes a normal appearance. Cortical thickening may persist as periosteal new bone remodels.

Question 26

Answer 26

early typical panosteitis often starts near nutrient foramens

Question 27

How can you differentiate osteogenesis imperfecta from nutritional secondary hyperparathyroidism radiographically? a) excessively opaque callus formation is seen in OI b) the dentin is thin in secondary hyperparathyroidism c) folding fractures are seen in OI d) in OI the bone is more radiodense than normal

Answer 27

A the dentin is also thin in OI

Question 28

what disease is this? in cats what virus is possibly related to it?

Answer 28

osteoporosis FeLV

Question 29

Answer 29

knees and teeth syndrome unlike traumatic pelvic fractures that tend to occur in groups of three fractures, these cats can have a single fracture

Question 30

which bones are not affected with craniomandibular osteopathy? a) ulna b) fibula c) occipital d) temporal bone

Answer 30

C CMO effects the mandibles, TMJs, bullae and can effect the ulna and fibula (similar to HOD) calvarial hyperostosis involved the frontal, temporal and occipital bones histologically the diseases are similar

Question 31

Osteopetrosis is caused by which of the following? Abnormal bone marrow function Abnormal osteoblast function Abnormal chondrocyte function Abnormal osteoclast function

Answer 31

Abnormal osteoclast function

Question 32

Osteogenesis imperfecta is cause by a defect in which collagen type? Structural defect in type I collagen Structural defect in type II collagen Structural defect in type III collagen Structural defect in type IV collagen

Answer 32

A

Question 33

Which of the following is the correct definition for Amelia? Absence of one or more limbs Fusion of two or more digits in a bony or soft tissue union Seperation of the medial and lateral portions of a limb with separation between any of the metacarpal bones Complete absence of one or more bone across a limb’s width (e.g. carpal agenesis or absence of the humerus)

Answer 33

Absence of one or more limbs

Question 34

Which of the following radiographic signs is not associated with congenital hypothyroidism Cuboid ossification in the carpus/tarsus is delayed There is stippling of the epiphysis with these alterations seen in the proximal tibia and humerus. The skull often appears shorter and broader than normal Vertebral bodies are shorter than normal due to endplate dysplasia

Answer 34

There is stippling of the epiphysis with these alterations seen in the proximal tibia and humerus. - is false

Question 35

Which of the following statements is correct regarding panosteitis Newfoundlands commonly have this disease and often have radiolucent zones surrounded by radioopaque osseus trabeculae of the distal radius and ulna On histopathology of the lesions, there is a marked inflammatory response seen Any part of the diaphysis can be affected, but often most pronounced near the nutrient foramen Male dogs are affected 2x more often than females

Answer 35

C