Exam 2: Osteochondritis Dissecans (OCD) Flashcards
__________ factors that stress the weakened osteochondral junction
play an important role in the clinical manifestation of osteochondrosis
and may ultimately determine whether healing or osteochondritis dissecans flap formation ensues.
Biomechanical
At what age is OCD seen in horses?
TWO age ranges:
Birth to 5 months
and
> 1 year old
Which 2 NSAIDS are used as anti-inflammatories
in the treatment of OCD in the equine?
Flunixin and Phenylbutazone
In regards to osteochondrosis,
exercised foals tended to have lesions involving the ________________
lateral trochlear ridge of the femur.
Small-chain collagen type in mammalian articular cartilage
May have a cell-signaling function
Type 6 collagen
What are the two pathophysiological causes of OCD?
Failure of blood vessels to penetrate calcified cartilage
Epiphyseal necrosis
_______ supplementation of mares during pregnancy may help decrease the prevalence of osteochondrosis
Copper
Aberrant local signaling to the ____________
in the deep layer of the articular epiphyseal-cartilage complex
is believed to underlie the development of osteochondrosis
chondrocytes
Which location is more likely to be affected by OCD
in the fetlock of the equine:
Sagittal ridge of MC3
Palmar/Plantar eminence of P1
P1 or MC3 Cysts
Sagittal ridge of MC3
Greater weight gains during the ___ and ____ months of life
appear to have the most influence on the development of osteochondrosis.
3rd and 5th months
What location is most commonly affected by OCD
in the Tibiotarsal (Tarsocrural) Joint (AKA HOCK)?
Distal intermediate ridge of the tibia
Major collagen type in hyaline cartilage
Type 2 collagen
During bone formation,
_____________ form calcified columns in the hypertrophic zone
Chondrocytes
What is the half-life of technetium-99 and how is it excreted?
12 hours, excreted via urine
Which location is more likely to be affected by OCD
in the stifle of the equine:
Lateral trochlear ridge
Medial trochlear ridge
Lateral trochlear ridge (#1 location in stifle)
What nutritional factors are involved in the epipathogenesis of osteochondrosis in horses?
LOW calcium, copper, selenium
HIGH phosphorus, zinc, molybdenum
Vitamin A,D deficiency
High protein diet
High caloric intake
For an arthroscopic procedure,
after the arthroscope is introduced, the egress cannula
is used with this technique to help facilitate direction
of the procedure
Triangulation technique
_______ is the only tissue in the body that can heal without scar formation
Bone
T/F: Degenerative osteoarthritis is a heritable trait
TRUE
Which location is more likely to be affected by OCD
in the hock of the equine:
Lateral trochlear ridge
Medial trochlear ridge
LATERAL trochlear ridge
(DIRT is still #1 though)
The process of abnormal bone and cartilage formation is known as
osteochondrosis
What 3 factors stimulate terminal differentiation of Chondrocytes?
Indian hedgehog
- Bone morphogenetic protein 6
- Bone morphogenetic protein 2
Compared with other affected foals,
foals confined in stalls tended to have more severe lesions,
and the _________ were more often affected.
femoral condyles
Which location is more likely to be affected by OCD
in the hock of the equine:
Lateral malleolus
Medial malleolus
Medial malleolus
(DIRT is still #1 though)
What location is most commonly affected by OCD
in the FETLOCK?
Sagittal ridge of MC3
Where in the stifle is this located and
what is the arrow pointing to?
Medial Femoral Condyle, Cyst
What is the most important sequela of OCD?
Degenerative osteoarthritis
T/F: Lameness is the first noticeable clinical sign of osteochondrosis
FALSE.
Lameness is rarely severe enough to be noticed
This is usually the primary clinical sign of osteochondrosis
Synovial effusion
In nuclear scintigraphy, Technetium-99 acts as _______,
so it gets incorporated into the bone about 2 hours after being given IV.
calcium
Major collagen type in fibrous connective tissue and bone
Not normally found in articular cartilage
Type 1 collagen
Normal healthy collagen is
collagen Type _____
2
What is the most common location to see
chip fractures in the carpus?
Distal Radial Carpal Bone
T/F: Nutrition imbalances can cause degenerative osteoarthritis
TRUE
Which 3 joints are most commonly affected by OCD in the equine?
- Tibiotarsal (Tarsocrural) Joint (AKA HOCK)
- Stifle
- Fetlock
The primary spongiosa is formed by ________ using calcified columns
Osteoblasts
What are 2 methods used to resurface cartilage
in the treatment of OCD in the equine?
Osteochondral dowel grafts
Autologous chondrocyte transplantation (ACT)
Osteochondrosis is a multifactorial disease.
What 4 factors contribute to development of this disease?
Nutrition
Growth Rate
Heriditary Factors
Trauma
What is your diagnosis?
OCD- Flap formation
How is OCD treated in the equine?
Rest
IA medication
Surgery- Arthrotomy/Arthroscopy
Meds- Joint supplements and chondroprotectants
Degenerative osteoarthritis
is associated with
______ Calcium
and
_________ Phosphorus
decreased calcium
increased phosphorus
What location is most commonly affected by OCD
in the STIFLE?
Lateral trochlear ridge
What are the 5 categories of chondroprotective
agents used to treat OCD?
Glucosamine
Chondroitin sulfate
Hyaluronic acid
Polysulfated glycosaminoglycans (PSGAGs)
Anti-inflammatories
• Small-chain collagen that is found only in
hypertrophic growth cartilage and the deep zone of adult articular cartilage
- Unknown function
- Considered a marker for hypertrophic cartilage
Type X collagen
Cysts are most common at this location in the stifle joint
MEDIAL femoral condyle
What is the sex predilection for degenerative osteoarthritis?
2:1 Males:Females
______ bone is responsible for supporting cartilage
Subchondral
Bone and cartilage are formed by a process known as
Endochondral ossification
Which 4 agents are used in gene therapy
as treatment for OCD in equines?
IL-1
IL-like GF1
IRAP (IL1 receptor antagonist protein)
PRP (platelet rich plasma)
Which 3 Polysulfated Glycosaminoglycans (PSGAGs)
are used as chondroprotectants in the treatment of OCD
in the equine?
Myristol
Cosequin
Adequan
Synovial effusion of the tarso-crural (aka tibiotarsal) joint is known as
BOG spavin
Chip fractures of the carpus occur most commonly
in which 3 locations?
Distal radial carpal bone (#1)
Proximal intermediate carpal bone
Distal lateral radius
How is degenerative osteoarthritis (DJD- degenerative joint disease) diagnosed?
Nuclear scintigraphy with Technetium-99
What 3 factors inhibit terminal differentiation of Chondrocytes?
Parathyroid hormone–related peptide
- Transforming growth factor–β1
- Bone morphogenetic protein 7
A joint disorder in which cracks form in the articular cartilage and the underlying subchondral bone due to blood deprivation in the subchondral bone.
This loss of blood flow causes the subchondral bone to die
in a process called avascular necrosis.
OCD- Osteochondritis Dissecans
