Chapter 89 - OCD Flashcards
What does “osteochondritis dissecans” mean?
Inflammation of bone and cartilage resulting in loose fragments.
What condition is most commonly associated with osteochondrosis in horses?
Developmental orthopedic disease (DOD).
What does the term “osteochondrosis” refer to?
A disorder of bone development in growing horses.
What is the primary characteristic of “osteochondritis dissecans”?
Cartilaginous or osteochondral separation.
What does “OC latens” represent?
Focal chondronecrosis in the growth cartilage.
What does “OC manifesta” indicate?
Impaired endochondral ossification and cartilage retention.
What does “OC dissecans” describe?
Cleft formation in necrotic cartilage.
What are examples of JOCC?
OCD, cuboidal bone disease, and other immature skeletal failures.
What term includes disorders related to immature joints or growth plates?
Juvenile osteochondral conditions (JOCC).
What is “endochondral ossification”?
The process of bone development from cartilage.
At what stage does endochondral ossification begin?
Fetal stage.
What is Wolff’s law?
Bone remodels in response to biomechanical load.
Where does longitudinal growth of long bones occur?
At growth plates or physe
What is the typical presentation of an OC patient?
A yearling with joint effusion, usually without lameness.
Which breed shows a high prevalence of OC in the tarsocrural joint?
Warmbloods and Standardbreds.
Which advanced imaging modalities outperform radiography?
Computed tomography (CT) and magnetic resonance imaging (MRI).
What is the role of radiography in diagnosing OC?
It’s the gold standard for detecting OC lesions.
Which joint commonly shows evidence of OC on radiographs?
The tarsocrural or femoropatellar joint.
What joints are most affected by OC in horses?
Tarsocrural, femoropatellar, and MCP/MTP joints.
What is a limitation of radiography for OC?
It may miss lesions limited to cartilage or subtle bone changes.
What joints are most often affected bilaterally by OC?
Tarsocrural and femoropatellar joints.
What is a predilection site for OC in the tarsocrural joint?
Distal intermediate ridge of the tibia.
What is the common location of OC in the shoulder joint?
The glenoid and humeral head.
Where are OC lesions commonly found in the femoropatellar joint?
Lateral trochlear ridge of the femur.
Are POFs part of OC?
No, they are traumatic in origin.
What do POFs indicate histologically?
More osteoarthritis than osteochondrosis.
What biomarker profile difference exists between OC and traumatic joint injuries?
OC has an increase in C2C, while traumatic injuries have increased CPII.
Can young foals show lameness with OC?
Yes, especially with large lesions in the femoropatellar joints.
What role does genetic predisposition play in OC?
Racing Thoroughbreds.
What makes diagnosing OC in very young animals challenging?
The lack of mineralization in subchondral bone.
Can OC lesions regress in young animals?
Yes, they can regress during early juvenile phases.
What is the primary period for the development of OC?
During active endochondral ossification in growing animals.
At what age do tarsocrural lesions typically resolve?
By 5 months, though some persist.
When do femoropatellar lesions commonly stabilize?
Around 8 months of age.
What was a unique finding in Lusitano foals regarding OC?
More lesions at 1 month of age in the femoropatellar joint.
Can minor OC lesions resolve after 12 months?
Yes, up to 24 months in some cases.
What is the “age of no return” for lesion resolution in most joints?
Generally set at 12 months.
What enzyme’s level change reflects cartilage metabolism in young animals?
Matrix metalloproteinase-3 (MMP-3).
Why does the healing of cartilage lesions decrease with age?
Due to reduced metabolic and repair capacity.