Joint Pathology

Question 1

What is bone congruence?

Answer 1

How well the bones fit each other, important for the distribution of pressure

Question 2

What is the content of cartilage matrix?

Answer 2

Collagen, GAGs, hyaluronic acid

Question 3

What is the function of GAG in the cartilage

Answer 3

attract water

Question 4

Why isn’t the synovial membrane classified as an epithelium

Answer 4

It doesn’t have basement membrane or junctional complexes like desmosomes

Question 5

What are the type A chondrocytes like?

Answer 5

Macrophage

Question 6

What are the type B chondrocytes like?

Answer 6

Fibroblast

Question 7

What is the function of type B chondrocyte?

Answer 7

produce ECM (hyaluronic acid production)

Question 8

How can we tell between type A and type B chondrocytes on histology?

Answer 8

Type A cells are multi-nucleated giant cells

Question 9

What are the treatments of osteoarthritis?

Answer 9

physiotherapy, pain relief and joint replacement

Question 10

What are the main differences between RA and osteoarthritis?

Answer 10

RA tends to be diffused. It can affect skin, heart and lung

RA stiffness gets better through the day. OA gets worst with use

Question 11

T/F RA usually starts in the major large joints of the body

Answer 11

False, they start in the small joints of hands and feet

Question 12

T/F Gout is an acute form of osteoarthritis

Answer 12

True, inflammation is caused by crystalisation of uric acid

Question 13

What are the treatments of gout?

Answer 13

anti-inflammatory medication, urate lowering therapy, lifestyle changes

Question 14

What are the major enzymes and cytokines involved is OA?

Answer 14

collagenase, MMP

IL-1

Question 15

What is the trigger of OA?

Answer 15

chondrocyte damage, leading to proliferation and enzyme/cytokine secretion

Question 16

What are some bone changes that can occur with OA?

Answer 16

bone thickening, microfractures,

Question 17

What is fibrillation of cartilage

Answer 17

erosion of cartilage

Question 18

What is bone eburnation?

Answer 18

thickening, and bone appears white and shiny

Question 19

T/F OA is a diffused degenerative disease in the joint

Answer 19

False, it is focal. You get non-uniform loss of cartilage, subchondral thickening and osteophytes

Question 20

What are the signs of OA?

Answer 20

reduced RoM
Crepitus (grinding of joint)
Osteophytes

Question 21

What are the symptoms of OA?

Answer 21

insidious onset, deep achey pain that is worse with activity

no systemic symptoms

Question 22

What is the diagnosis of OA?

Answer 22

Mostly clinical

Question 23

What is the underlying pathological process of RA?

Answer 23

T helper cells activation, especially Th1 and Th17

TNF-a is central to RA inflammatory process, activating B plasma cells

Question 24

What kind of change do activated B cells do to the synovium?

Answer 24

they induce fibroblasts, macrophages and osteoclasts to make synovium hyperplastic, and deposit abnormal granulation tissue “pannus”

Question 25

What is the role of activated macrophage in RA?

Answer 25

secrete collagenases and MMPs to break down cartilage and bone

Question 26

What is the morphology of RA on histology?

Answer 26

villous hyperplasia mononuclear infiltrate germinal centres

Question 27

What is the presentation of late stage RA?

Answer 27

union of bones due to extensive fibrosis and destruction of capsule and ligaments

Question 28

What are the signs of RA?

Answer 28

warm, swollen joints rheumatoid nodules joint deformity in later stage

Question 29

T/F there are systemic symptoms from RA

Answer 29

True, patients can have fever, loss of weight, anaemia

Question 30

T/F RA is usually asymmetrical

Answer 30

False, the disease process is symmetrical

Question 31

Which joint is often sparred in RA?

Answer 31

distal interphalangeal joint

Question 32

T/F Granulomatous inflammation is typical of RA

Answer 32

True, there is central necrosis, epithelioid macrophages and surrounding lymphocytes

Question 33

What are the specific tests for RA?

Answer 33

Test for rheumatoid factor or anti-cyclic citrullinated peptided

Question 34

What is the effect of crystals on neutrophils in gout?

Answer 34

they are spiky and can pierce neutrophils, killing them and release internal inflammatory mediators

Question 35

T/F Pannus can occur in both OA and gout

Answer 35

True

Question 36

What is tophi?

Answer 36

urate deposition that can be seen superficially

Question 37

T/F Granuloma can be seen in RA, but not in gout

Answer 37

False, you can see granuloma in tophi

Question 38

T/F Serum urate is a good diagnostic technique for gout

Answer 38

False, acute gout attack lowers serum urate + most people with high urate don't have gout

Question 39

What is the gold standard test for gout?

Answer 39

joint aspiration