Osteochondrosis Dissecans (OCD)

Question 1

__________ is the process of abnormal bone and cartilage formation

Answer 1

osteochondrosis

Question 2

What is the definition of osteochondrosis dissecans (OCD)?

Answer 2

Lesions that penetrate the joint surface creating inflammation and effusion​

Question 3

Bone and cartilage form via the process of __________

Answer 3

Endochondral ossification​

Question 4

Primary spongiosa is formed by __________ using calcified columns

Answer 4

osteoblasts

Question 5

Osteochondrosis develops due to failure of blood vessels to penetrate the calcified cartilage and occlusion of canals, causing epiphyseal necrosis.

What happens as a result of the failure of blood vessels to penetrate the calcified cartilage?

Answer 5

• Persistence of cartilage
• Formation of cysts
• Formation of fissures and a flap

Question 6

What are the two age groups in which cartilage defects most commonly occur?

Answer 6

• Birth - 5 months of age
• Greater than 1 year

Question 7

Are males or females more overrepresented in cases of osteochondrosis?

Answer 7

Males

2:1 Male:Female ratio

Question 8

What nutritional factors may lead to osteochondrosis?

Answer 8

• Low calcium, high phosphorus
• Trace minerals (excess zinc, copper deficit)
• Vitamin A and D deficiency
• High protein diet
• High caloric intake

Question 9

T/F: Osteochondrosis causes severe lameness in horses

Answer 9

False

Osteochondrosis causes slight lameness in horses

Question 10

Is OCD usually unilateral or bilateral?

Answer 10

bilateral

Question 11

Why is OCD only slightly painful?

Answer 11

There are no nerves in cartilage

Question 12

What modalities are used to diagnose OCD?

Answer 12

radiographs, scintigraphy, arthroscopy, MRI

Question 13

What joint is most commonly affected by OCD?

Answer 13

tibiotarsal joint (hock)

Question 14

What is the second most common joint affected by OCD?

Answer 14

stifle

Question 15

What are the two most common locations for OCD on the hock?

Answer 15

• Distal intermediate ridge of the tibia (most common)
• Lateral trochlear ridge (2^nd most common)

Question 16

T/F: The medial and lateral malleolus are the areas of the hock most commonly affected by OCD

Answer 16

False

• The distal intermediate ridge of tibia is the most commonly affected region of the hock.*
• The medial and lateral malleolus are affected by OCD, but only rarely.*

Question 17

Which regions on the stifle are affected with OCD?

Answer 17

• Lateral trochlear ridge
• Medial trochlear ridge
• Medial femoral condyle (cyst)

Question 18

What are the treatment options for OCD?

Answer 18

• Rest
• Intra-articular medication
• Surgery (arthroscopy)

Question 19

Beyond arthroscopy, what are some advanced surgical options for treatment of OCD?

Answer 19

• Ostochondral dowel grafts
• Autologous chondrocyte transplantation (ACT)
• Gene therapy

Question 20

“Placement of in vitro cultivated chondrocytes under a periosteal flap to allow for proliferation of the cells” describes what surgical treatment for OCD?

Answer 20

Autogenous Chondrocyte Transplantation (ACT)

Question 21

T/F: Stem cells are generically defined as undifferentiated cells that are capable of self-renewal through replication as well as differentiation into specific cell lineages

Answer 21

True

Question 22

Hematopoietic stem cells (HSC) are well characterized cells of __________ origin, and provide the basis for bone marrow transplant procedures.

Answer 22

mesodermal