DEVELOPMENTAL DISEASES OF THE MUSCULOSKELETAL SYSTEM

Question 1

What happens during endochondral ossification

Answer 1

• Cartilage is replaced by bone

- Responsible for the majority of skeletal growth during feral development

Question 2

What does endochondral ossification allow in growing animals

Answer 2

-allows mechanism for growth whilst simultaneously allowing weight bearing

Question 3

Where does endochondral ossification occur in the growing animal

Answer 3

• physio/ growth plate
• articular-epiphyseal cartilage complex AECC
• Cuboidal bones

Question 4

What is endochondral ossification responsible for at the physis

Answer 4

The majority of longitudinal bone growth

Question 5

What is endochondral ossification responsible for at the AECC

Answer 5

For radial expansion of the epiphysis

Question 6

Review the endochondral ossification process

Answer 6

The growth cartilage has blood vessels in cartilage canals. As growth slows and layer of growth cartilage becomes thinner, cartilage canals undergo chondrication

Question 7

Define osteochondrosis

Answer 7

Failure of endochondral ossification- is a developmental skeletal disorder of unknown aetiology

Question 8

List the 4 most common sites of OCD in the horse

Answer 8

• Tibiotarsal joint/hock
• Femoropatellar joint/ stifle
• Fetlock joint
• shoulder
• elbow
• hip- less common

Question 9

List the most common sites of OCD in dog

Answer 9

Shoulder- caudal aspect of humeral head
Stifle- lateral & medial femoral condyle
Elbow- coronoid process of the ulna, medial condyle of the humerus

Question 10

What is osteochondritis

Answer 10

Extension of lesions to the articular surface causing inflammation of the joint

Question 11

What is osteochondrosis dissecans (OCD)

Answer 11

Presence of a dissecting osteochondral flap