Ortho 1

Question 1

1.5 YO DSH with acute onset pelvic lame limpness, worse in right. what do you suspect?

Answer 1

slipped capital femoral epiphysis

Question 2

10 month jack Russel terrier with acute. onset right pelvic limb lameness. what condition do you suspect?

Answer 2

avascular necrosis of femoral head
(looks similar to hip luxation, but there is radiolucency and overtime the femur neck will look moth-eaten; with hip luxation will be radiopaque)

Question 3

purpose of vet orthopaedics

Answer 3

restore or improve patieht comfort, mobility, and function

Question 4

what are the 6 types of arthritis

Answer 4

noninflammatory: OA, traumatic, coagulopathic.
inflammatory: immune mediated, infective, crystal induced.

Question 5

pathogenesis of OA: what are 5 changes to tissues in synovial joint

Answer 5

metabolism and morphology of articular cartilage
subchondral bone metabolism and architecture (sclerosis)
formation of osteophytes and enthesophytes
synovial inflammation
fibrosis

Question 6

what 4 inflammatory cytokines are the key components of degenerative OA

Answer 6

interleukins 1, 7, 8, and TNF alpha

Question 7

pathogenesis of OA: besides the changes in all tissues of the synovial joint, what are other body tissues that are affected

Answer 7

surrounding muscle, ligaments, tendons
CNS sensitization leads to neuropathic pain (hyperpathia, hyperalgesia, allodynia)

Question 8

etiology of OA: what 3 factors predispose to arthritis

Answer 8

genetics: breed predisposition
age
systemic factors, especially obesity

Question 9

etiology of OA: what 4 factors contribute to abnormal joint biomechanics
(hint: not genetics, age, obesity; think things relating to joint physics)

Answer 9

injury, developmental abnormality, instability, overload

Question 10

compare owner-reported history of a typical dog with OA and a typical cat with OA. which species can you use owner-reported questionnaires for tracking OA severity?

Answer 10

Dog: reluctant to exercise, inactivity stiffness, lameness, inability to jump, behavioural changes eg. aggression, influenced by volume of activity and weather and typically gradually worsening.
Cat: more hidden signs like reduced activity, decreased jump height, scruffy looking, aggression, being withdrawn.
Validated owner questionnaires in dogs but more difficult in cats.

Question 11

clinical signs of OA in dogs

Answer 11

behaviour and gait: stiffness, lameness, gait alterations (bunny hopping and short strides), reluctance to exercise, exercise intolerance
PE: muscle atrophy, joint swelling, capsular fibrosis, joint effusion, decreased ROM, crepitus, pain

Question 12

how can you differentiate between neurological and orthopedic-related muscle atrophy

Answer 12

NEURO-related muscle atrophy looks WORSE bc there is a lack of electrical impulse at muscle, causing RAPID and dramatic muscle atrophy
ORTHO-related muscle atrophy is due to disuse and will be GRADUAL

Question 13

clinical signs of OA in cats

Answer 13

“aversive responses to discomfort”
does poorly on performance tests (get to jump up or down)
harder to tell than PE for dog, ask owners to take videos from home

Question 14

what is the most valuable and cost effective means to assess a joint for OA

Answer 14

arthroscopy!
(the gold standard for articular surface evaluation and can do therapeutic tx too. if any doubt about underlying disease process do arthroscopy and evaluation)

Question 15

what are some radiographic features of OA

Answer 15

osteophytosis, enthesophytes, effusion, soft tissue swelling, subchondral sclerosis, intraarticular mineralization, subchondral cysts
note images aren’t weight bearing so be cautious about interpreting joint space

Question 16

how to manage OA

Answer 16

• WEIGHT MANAGEMENT
• regular, moderate, controlled EXERCISE
• symptom management drugs: NSAIDs, Solensia for cats and Liberal for dogs (MONOCLONAL ANTIBODIES), other drugs
• structure modifying agent drugs. eg. PSGAGs
• nutraceuticals eg. OMEGA 3 FATTY ACIDS
• lifestyle modifications
• maybe mesenchymal stem cells
• surgical management in end stage management

Question 17

what is osteochondrosis

Answer 17

disorder of ordered process of endochondral ossification
can be focal or multifocal and is often bilaterally symmetric

Question 18

what are the 3 types of osteochondrosis lesions? and which stage do we usually see clinical signs at

Answer 18

1. osteochondrosis latens = early miscroscopic lesion
2. osteochondrosis manifesta = subclinical lesions radiographically and clinically apparent
3. osteochondrosis dissecans (OCD) = semi-attached or loose cartilage flaps (joint mice) present and causing C/S
   usually diagnosed at OCD stage

Question 19

what is wrong

Answer 19

humeral head has a divet, is not flat
this is OCD in a dog

Question 20

4 common locations of OCD in a DOG

Answer 20

1, 2: humerus “double hit”: caudomedial humeral head and medial aspect of distal humeral condyle
3. lateral or medial femoral condyle
4. medial or lateral trochlear ridge of talus
(so you should look at the shoulders, elbows, stifles, tarsal joints especially)

Question 21

should you breed animals with OCD

Answer 21

no, most forms of OCD are inherited as a polygenic trait
(although also related to joint morphology, limb conformation, and rapid growth (ie. really big dogs))

Question 22

describe pathogenesis of OCD

Answer 22

• damage to blood vessels from trauma or conformational forces, if major enough, leads to
• avascular necrosis of developing epiphyseal cartilage
• leads to defect in subchondral bone and potentially fissuring or fracture of overlying cartilage
• thickening of elevated cartilage flap
• we don’t fully understand it

Question 23

typical presentation of OCD in a dog

Answer 23

4-9 month large breed dog presenting with lameness and exercise intolerance
PE: pain and joint effusion, often bilateral lesions, potentially bilateral lameness

Question 24

what radiographic changes can be seen in a dog with OCD

Answer 24

defect in subchondral bone with flattening or concavity of normal bone contour, possibly sclerotic bone margins (brighter white)
possible mineralized cartilage flaps, attached or as joint mice

Question 25

what is gold standard for diagnosis of OCD

Answer 25

arthroscopy
in practice usually diagnosed based on rads

Question 26

OCD prognosis for shoulder, stifle, medial humeral condyle, and talus - which is the best prognosis and which is the worse

Answer 26

best = shoulder
middle = stifle (px guarded to fair, decent if treated at early age) and distal medial humeral condyle (good results if early surgery)
worst = talus (long term px is guarded to poor and surgical tx is controversial)

Question 27

will OA develop if OCD is present

Answer 27

for talus, distal medial humeral condyle, and stifle, yes
for shoulder, prognosis is excellent if surgically treated <12 months and prognosis is very good in older animals, still possible joint will progress over time to OA

Question 28

describe NONsurgical management of OCD

Answer 28

NSAIDs, exercise restriction and crate confinement, dietary supplements (omega 3, glucosamine, chondroitin, calorie restricted diet
OR, if shoulder OCD in young dog, vigorous exercise to get the flap to detach (yes the flap goes somewhere, just hope it doesn’t go somewhere bad)

Question 29

what dogs are good candidates for NONsurgical management of OCD

Answer 29

<6.5 month dogs with mild clinical signs, either no joint mice or in unimportant location
OR, dogs with advanced secondary OA where clinical value of flap removal is limited (talar OCD)

Question 30

name surgical management techniques of OCD

Answer 30

restorative techniques:
fragment reattachment; osteochondral transplants (autographs) for stifle, shoulder, elbow; synthetic osteochondral resurfacing

Question 31

acute pelvic limb lameness in a toy breed dog.
what do you suspect

Answer 31

avascular necrosis of the femoral head
(why?
- toy breed and terrier issue of dogs 4-11 months.
- see mild intermittent lameness.
- apple core appearance (aseptic necrosis of femoral head and neck) seen on rads).

Question 32

acute pelvic limb lameness in a 5 month MN overweight cat.. no history of trauma.
what do you suspect

Answer 32

slipped capital femoral epiphysis
(why?
- reported in cats and dogs, but mostly cats: male neutered overweight cats age 4.5-42 months
- C/S lameness, poor jump, weakness, crepitation, pain, 40% bilateral
- looks like a SH-1 fracture but is not, and not traumatic cause)

Question 33

what view is this

Answer 33

frog-leg VD view of pelvis
(it is helpful for pelvic rads)

Question 34

young, rapidly growing large/giant breed of dog, male > female condition, C/S swelling of distal metaphases of radius, ulna, tibia, pyrexia, anorexia, pain inability to walk. what is wrong

Answer 34

hypertrophic osteodystrophy
look for double physics line in rads

Question 35

what is wrong? what is this condition associated with

Answer 35

hypertrophic osteopathy
often associated with primary or metastatic neoplasia

Question 36

large/giant breed but also smaller breeds including Mini Schnauzer and Scottish terrier. usually age 5-12 months, males > females.
what is wrong? how to treat?

Answer 36

panosteitis
self limiting noninflammatory disease of long bone marrow
rest and analgesics