Joint reaction to injury Flashcards
(39 cards)
What is inflammation of a joint called?
arthritis
Where does exudate come from in arthritis?
the synovium
What happens to synovial fluid in arthritis and what does it cause?
it breaks down and causes a decrease in boundary lubrication causing it to be very watery
What does synovial villous hypertrophy and hyperplasia cause?
proliferation of synoviocytes and chondrification of villi
What is chondrification of villi?
when villi form in the joint space
Why is chondrification of villi bad?
because they can break up and float around in the joint
How does fibrosis to the joint capsule affect the joint?
it can cause it to become less flexible and moveable
What is pannus?
the growth of fibrovascular tissue over articular cartilage
What can pannus progress to?
fibrous ankyloses
What is pannus a hallmark of?
rheumatoid arthritis
What is chondromalacia?
the softening of the cartilage
What specifically happens to cartilage to animals with chondromalacia?
there is thinning and fibrilation of the cartilage due to matrix loss (broken down by matrix metalloproteinases), and there is an increase in wear and tear due to loss of lubrication
What are chondrocyte clusters and when do they occur?
chondrocyte hyperplasia when there is ineffective repair
When does chondrocyte necrosis happen?
when there is injury at articular cartilage from inflammation
What is the mechanism of chondrocyte necrosis?
ischemia of the AE complex that causes the failure of endochondrial ossification leading to osteochondrosis dessicans
What is the best mechanism the body has for fixing joint damage?
replacement with fibrocartilage
What is another name for subchondral bone hyperostosis?
eburnation
What is subchondral bone hyperostosis?
increased focal compression on the subchondral plate
What can cause subchondral bone hyperostosis?
loss of cartilage or abnormal joint loading
What is periarticular osteophyte formation?
focal hyperostosis at attachment points of the joint capsule (edge of articular surface)
Why does periarticular osteophyte formation happen?
abnormal joint loading and instability
What is commonly associated with periarticular osteophyte formation?
bony ankyloses
What neoplasias, although not common, can cause joint injury?
synovial cell carcinoma and histocytic sarcoma
What lesion is shown here?
fibrinopurulent arthritis
