Osteoarthritis B&B

Question 1

which of the following forms of arthritis is most common?
a. rheumatoid arthritis
b. septic arthritis
c. gouty arthritis
d. psoriatic arthritis
e. reactive arthritis
f. osteoarthritis

Answer 1

f. osteoarthritis

Question 2

which type of joints are affected by osteoarthritis?

Answer 2

synovial joints - fingers, hips, knees

articular cartilage is made of type II cartilage, synovium secretes synovial fluid made of hyaluronic acid

Question 3

what type of cartilage is found in synovial joints?

Answer 3

Type II collagen

[synovial joints = fingers, hips, knees]

Question 4

describe the pathophysiology of osteoarthritis (2)

Answer 4

1. hyaline cartilage breakdown
2. abnormal chondrocytes - normally quiescent, begin to proliferate and secrete proteases/cytokines, then die

Question 5

which type of arthritis will NOT present with a significantly elevated WBC?

Answer 5

osteoarthritis - low WBC in synovial fluid

normal = <200
osteoarthritis = 200-2000
rheumatoid arthritis = 2k-50k
gout = 2k-50k
septic arthritis = >50k

Question 6

what are the classic x-ray findings of osteoarthritis? (4)

Answer 6

1. joint space narrowing - hyaline cartilage breakdown
2. subchondral sclerosis - thickening of bone just below joint space
3. osteophytes (bone spurs) - thickening of subchondral bone at joint edges (insertion points)
4. subchondral cyst - fluid filled sacs at edge of joint, due to bone cracks

Question 7

which joints of the hands are most impacted by osteoarthritis vs rheumatoid arthritis?

Answer 7

osteoarthritis - DIP and PIP joints (distal/proximal interphalangeal)

rheumatoid arthritis - MCP (metacarpal-phalangeal)

Question 8

nodal osteoarthritis

Answer 8

swellings (nodes) of the DIP/PIP joints in patients with interphalangeal osteoarthritis

Question 9

Heberden’s vs Bouchard’s nodes

Answer 9

nodal osteoarthritis - swellings of the interphalangeal joints in patients with osteoarthritis

Heberden’s - occur at DIP (distal) joints
Bouchard’s - occur at PIP (proximal) joints

Question 10

which part of the spine is involved in osteoarthritis?

Answer 10

facet joints - these are synovial joints

most commonly lower cervical spine (neck pain) or lower lumbar spine (lower back pain)

Question 11

how do the symptoms of rheumatoid arthritis differ from osteoarthritis?

Answer 11

autoimmune condition (joints have high synovial WBC count), affects women 40-50yo (younger than osteoarthritis)

morning stiffness that improves with use of joints (opposite of osteoarthritis)

also presents with systemic complications (due to autoimmunity) - uveitis, serositis, Baker’s cyst

Question 12

how do the symptoms of septic arthritis differ from osteoarthritis?

Answer 12

acute onset of swelling/pain in single joint + fever/chills/sweats

synovial fluid has high WBC count and positive bacterial culture (S. aureus, S. pneumoniae, or N. gonorrhoeae from hemotogenous seeding)

acute monoarthritis = medical emergency, must tap synovial fluid to exclude septic arthritis or gout

Question 13

how can hemochromatosis be differentiated from osteoarthritis, both of which cause bone pain/aching?

Answer 13

hemochromatosis (iron overload) may present as arthritis first, but occurs in younger patient with minimal swelling and high serum ferritin

affects MCP joints (osteoarthritis affects DIP/PIP)

Question 14

symptoms of arthritis in a young patient affecting the MCP joints + high serum ferritin =

Answer 14

hemochromatosis (iron overload) may present as arthritis first, but occurs in younger patient with minimal swelling and high serum ferritin

affects MCP joints (osteoarthritis affects DIP/PIP)