Lecture 19: Osteochondrosis/Osteochondritis Dessicans (Exam 3)

Question 1

Definition:

A process where growth cartilage in epiphyses and growth plates is gradually turned into bone through a sequence of matrix mineralization, chondrocyte death, vascularization, and ossification.

Answer 1

Endochondral ossification

Question 2

Definition:

a failure in the normal process of endochondral ossification

Answer 2

osteochondrosis

Question 3

osteochondrosis commonly occurs in shoulder elbow stifle and hocks of what type of breed dogs

Answer 3

large and giant

Question 4

What is the clinical manifestation of osetochondrosis

Answer 4

osteochondritis

Question 5

Osteochondrosis involvement of epiphyseal physis results in chondro-osseous flaps

Answer 5

osteochondritis dissecans

Question 6

What is this showing

Answer 6

osteochondrosis(focal area of delayed ossification)

Question 7

In order to diagnose osteochondritis dissecans radiographic appearance must be accompanied by what

Answer 7

clinical sings (referable to the joint involved (OCD)

Question 8

What is affecting this patient?

Answer 8

osteochondrosis

Question 9

What is affecting the left? What about the right?

Answer 9

• Left: osteochondritis dissecans
• Right: osteochondrosis

Question 10

Osteochondrosis leas to what at deep portion of the thickened cartilage

Answer 10

necrosis (susceptible to trauma)

Question 11

Can you breed osteochondrosis dogs?

Answer 11

You can but you shouldn’t (genetic predisposition)

Question 12

What can be a contributing factor to flap formation

Answer 12

microtrauma (location of biomechanical stress seen predisposed by repeat microtrauma)

Question 13

Diets high in what two things may predispose patients to osteochondrosis in GREAT DANES? What can this diet cause

Answer 13

• calcium and vitamin D3
• in all breeds - increased growth rates, increased muscle mass and BW

Question 14

Large and giant breeds with rapid what are predisposed to osteochondrosis

Answer 14

growth (overfeeding energy increases growth hormones)

Question 15

What breed types are mainly affected by osteochondrosis of the humerus? What gender? What age?

Answer 15

• large and giant breed dogs
• males more than females
• 4-8 months old)

Question 16

What diagnostic tools do you need for diagnosis of osteochondrosis

Answer 16

• routine radiographs
• ALWAYS RADIOGRAPGH BOTH JOINTS (BILATERAL USUALLY)
• can use CT and MRI but really not needed

Question 17

What will you primarily see on radiography that indicated osteochondrosis

Answer 17

• irregularity in the subchondral bone contour on caudal aspect of humeral head
• may see calcified flap

Question 18

What is the diagnosis of this patient?

Answer 18

osteochondrosis (sudden flattening and faint line on caudal aspect of femoral head indicating a flap)

Question 19

Should medical management or sugery be used?

• Pain & lameness on presentation
• Typically indicates OCD vs. OC
• Greater than 8 months of age
• Joint mouse present(free fragments)
• Large lesions

Answer 19

Surgery

Question 20

Should medical management or sugery be used?

• <6.5 months of age
• Small lesions on radiographs w/ no free fragments
• No lameness or clinical pain on palpation

Answer 20

Medical management

Question 21

What is the goal of surgical repair of osteochondritis dissecans

Answer 21

• removal of osteo-chondral flap
• debridement of exposed subchondral bed

Question 22

What is seen here on this arthroscopic image

Answer 22

osteochondritis dissecans

Question 23

What is affecting this patient

Answer 23

osteochondrosis of the elbow (Irregularity in normal subchondral bone contour on medial aspect of the humeral condyle)

Question 24

Will you get a cranial drawer on a patient with osteochondrosis?

Answer 24

• slight possible
• Patients are young and OCD can cause space in the joint allowing it to move more

Question 25

OCD lesions in the stifle are present where?

Answer 25

medial aspect of the lateral femoral condyle

Question 26

What would you diagnose this patient with?

Answer 26

Osteochondrosis of the stifle

Question 27

What procedure can you preform in the stifle that is different than other areas of osteochondrosis

Answer 27

Osteochondral plug transfer (OATS- osteochondral autograft transfer system)

Question 28

What does OATs do

Answer 28

transfers cartilage from away from the joint surface to the joint surface

Question 29

What breed of dogs are most commonly affected by osteochondritis of the tarsus

Answer 29

rottweilers

Question 30

Of the OCD lesions what is the poorest diagnosis

Answer 30

tarsal OCD

Question 31

What symptom might you see in tarsal osteochondrosis that would help differentiate from stifle

Answer 31

* hyperextended hocks * may be unable to flex hocks

Question 32

What is the most common area of tarsal osteochondrosis

Answer 32

medial trochlear ridge

Question 33

What would you diagnose this patient with

Answer 33

Osteochondrosis of the tarsus

Question 34

Why will many surgeons not consider surgery with tarsal osteochondrosis

Answer 34

destabilization of tarsus (poor prognosis - medical management isnt much better)

Question 35

What medical management techniques can be used for tarsus osteochondrosis with small lesions in nonclinical patients

Answer 35

* NSAID and DMOA (diseased modified osteoarthritic lesions) * cage rest * diet modifications

Question 36

in osteochondrosis surgery you should debride until when

Answer 36

subchondral bone bleeds

Question 37

# **OCD prognosis:** caudal aspect of humeral head?

Answer 37

good to excellent

Question 38

# **OCD prognosis:** fragmented medial coronoid process of the ulna?

Answer 38

fair to good (medial humeral condyle varies)

Question 39

# **OCD prognosis:** OCD prognosis: lateral > medial femoral condyle?

Answer 39

guarded to fair

Question 40

# **OCD lesion prognosis:** medial trochlear ridge of the talus

Answer 40

fair to poor