MSK pt 3 Flashcards
what happens with articular cartilage is damaged?
hyaline cartilage replaced by fibrocartilage
What is the synovial fossa?
normal clefts in non-weight bearing cartilage surfaces in horses, pigs, ruminants
articular cartilage has limited blood supply, which means that there is limited _____ capacity
regenerative
what are erosions?
superficial defects that persist/won’t fill in
what are ulcerations?
full-thickness defects where mesenchymal cells can access site of injury, leading to it being filled with fibrocartilage
if you have a joint injury and feel pain, what does that mean?
that the articular cartilage is not the only thing that is impacted. If only articular cartilage is affected, there is no pain. There must also be injury to the synovium or subchondral bone for pain to be present
Describe the positive feedback loop of injury to articular cartilage
- injury (sterile or infectious)
- stimulates an increase in enzymes, cytokines, prostaglandins, and other molecules
- destruction of cartilage matrix
- injury (cycle starts over)
what is the role of subchondral bone and where is it located?
located immediately below articular cartilage
supports articular cartilage and dissipates forces
describe the pathogenesis of how damage to or loss of articular cartilage leads to subchondral bone sclerosis
- damage/loss of articular cartilage
- increase in concussive forces reach subchondral bone
- response in accordance to Wolff’s law
- increase in bone formation with decrease in bone resorption
- net bone thickening –> subchondral bone sclerosis
What is eburnation?
complete ulceration of articular cartilage with exposure of subchondral bone
what is the name of the lesion in this picture
eburnation
why does eburnation look “shiny”?
exposure of the subchondral bone leads to increased bone density, and it is polished from bone-to-bone contact
you find these gnarly things in the synovium. what are they? what do they mean?
villous hypertrophy/hyperplasia
they mean injury/inflammation of the synovial membrane
Name the lesion labeled F and the lesion that looks like rumen papillae.
F: eburnation
the other stuff is villous hypertrophy or hyperplasia
Define these terms:
1. synovitis
2. arthritis
3. arthropathy
4. polyarthritis
5. hygroma
6. ankylosis
- inflammation of the synovial membrane, likely a response to cartilage debris within the joint
- generic term for joint inflammation
- generic term for joint disease
- inflammation of multiple joints
- fluid-filled sac that develops in areas of high pressure, including adjacent to joint
- joint fusion
what is an osteophyte? what causes is?
proliferative new bone along joint margins
response to inflammation and/or joint instability
what are the arrows pointing to?
osteophytes
What are the two classifications of arthritis, and what is the difference between them?
inflammatory and osteoarthritis
osteoarthritis is not caused by inflammation, and inflammatory arthritis is caused by inflammation
What are the 5 ways in which bacteria can enter joints?
- hematogenous
- extension from osteomyelitis
- spread from ST infection
- iatrogenic
- penetrating injury
What is suppurative arthritis?
joint inflammation associated with bacterial infection with purulent exudate in synovial fluid
what are the gross lesions of suppurative arthritis? tell me specifically about how the articular cartilage changes.
synovial fluid is turbid (pus) ± synovial membrane proliferation ± fibrin in joint
articular cartilage changes based on the chronicity:
- acute: normal to slightly thin
- chronic: severe erosions/ulcerations
what is “the great pus former” and something that causes suppurative arthritis in animals?
Truperella pyogenes
what is the lesion?
suppurative arthritis
this is a joint of an animal (idk what lol). the fluid in the syringe is synovial fluid. what is the lesion?
suppurative arthritis
suppurative polyarthritis of neonatal calves, foals, and lambs can start as what disease process?
embolic suppurative osteomyelitis of the growth plate that spreads into joint
can also start at epiphyseal/joint cartilage (site of epiphyseal growth)
what is fibrinous arthritis?
joint inflammation associated with bacterial infection with fibrinous exudate in synovial fluid
what are the gross lesions of fibrinous arthritis? tell me specifically about the articular cartilage changes.
synovial fluid containing fibrin, severe synovial membrane proliferation ± cartilage damage
articular cartilage changes with chronicity:
- acute: normal to slightly thin
- chronic: may develop cartilage damage erosions/ulcerations but not consistently
This is a joint. what is the lesion?
fibrinous arthritis
We have to know 5 examples of bacterial species that cause fibrinous arthritis. Name them and tell me which species is impacted.
Escherichia coli (cattle & pigs)
Haemophilus parasuis (pigs)
Streptococcus bovis (cattle)
Histophilus somni (cattle)
Streptococcus suis (pigs)
“Emmett Has Such Hot Stifles”
We have to know 5 examples of bacterial species that cause fibrinous arthritis. Name them and tell me what disease they cause (other than fibrinous arthritis lol)
Escherichia coli – bacterial septicemia
Haemophilus parasuis – Glasser’s Disease
Streptococcus bovis – Bacterial septicemia
Histophilus somni – Thrombotic meningoencephalitis
Streptococcus suis – bacterial septicaemia
“Emmett Has Such Hot Stifles”
This is a stifle joint. What is the lesion?
fibrinous arthritis
Histophilus somni can wreak havoc on cows. Name the 4 associated lesions that we should know.
- fibrinous arthritis
- myocarditis (remember boxing glove cut?)
- fibrinous pleuritis
- meningoencephalitis
There are different outcomes to both fibrinous and suppurative arthritis depending on if the inflammation is mild or severe. What is the outcome if the inflammation is mild?
resolution of lesions
There are different outcomes to both fibrinous and suppurative arthritis depending on if the inflammation is mild or severe. What is the outcome if the inflammation is severe?
enzymes, cytokines, prostaglandins, and other molecules –> damage cartilage and synovium –> osteoarthritis/degenerative joint disease
joint rigidity, loss of function, ankylosis