1.3 Joints

Question 1

synovium

-what does it secrete

Answer 1

• inner lining of synovial joint capsule
• secretes fluid rich in hyaluronic acid for lubrication

Question 2

How are symptoms different: osteoarthritis vs rheumatoid arthritis

-2 main symptoms

Answer 2

1. OA: morning stiffness gets worse, RA: morning stiffness gets better
2. Both DIP and PIP in OA, no DIP in RA

Question 3

Osteoarthritis:

-symptoms

Answer 3

1. Limited joints involved: DIP, PIP, knees, hips, lower spine
2. morning stiffness gets worse
3. osteophyte formation (classic nodes in DIP and PIP)

Question 4

osteophyte

Answer 4

small bony growths, seen in OA

Question 5

Rheumatoid Arthritis

• what genetics associated with
• who typically affected

Answer 5

HLA-DR4

-women of late childbearing age

Question 6

Rheumatoid Arthritis

• classic hallmark
• mech

Answer 6

• synovitis leading to formation of pannus, which fills joint space
• pannus is inflamed granulation tissue and contains myofibroblasts, which contract
• contraction moves joint bones in different directions
• increased osteoclast activity erodes bone
• joint fusion

Question 7

Pannus, in Rheumatoid arthritis

Answer 7

-inflammed granulation tissue that fills joint space, created by synovitis

Question 8

Rheumatoid Arthritis

-how do arthritic symptoms manifest?

Answer 8

• morning stiffness, gets better
• fingers: symmetric PIP joints–swan-neck deformity. DIP spared.
• limb joints: wrist, elbows, ankles, knees

Question 9

• what are rheumatoid nodules?
• where do they occur?
• cause?

Answer 9

• found in Rheumatoid arthritis
• central zone of fibrinoid necrosis surrounded by epitheloid histiocytes
• usually subcutaneous and over bony prominences, like knuckles and elbows. but also in visceral organs.
• caused by vascular damage from RA vasculitis.

Question 10

Rheumatoid arthritis:

-lab findings

Answer 10

• Rheumatoid factor: an IgM that binds to Fc portion of IgG
• marker of tissue damage

Question 11

Seronegative Spondyloarthropathies

• characterized by (3)
• list them (4)

Answer 11

• group of joint disorders, characterized by:
  1. no rheumatoid factor
  2. spine
  3. HLA-B27 association

“PAIR”

1. Psoriatic arthritis (sausage fingers/toes)
2. Ankylosing spondylitis (spine fused together)
3. Inflammatory Bowel Disease
4. Reiter Syndrome/Reactive arthritis (can’t see, can’t pee, can’t climb a tree)

Question 12

Infectious arthritis

• most common causes
• most common presentation

Answer 12

• most commonly caused by:
  1. Gonnorhea–sexually active young adults
  2. S Aureus -single joint, usually knee.

easy tx with Abx

Question 13

Secondary gout

-secondary to what? (3 disorders)

Answer 13

1. Leukemia, myeloproliferative disorders
   - increased cell turnover means more DNA breakdown, leading to purine buildup
2. Lesch-Nyhan.
   - loss of HGPRT means no salvage pathway for purines. More purines shunted into uric acid production
3. Renal insufficiency -unable to excrete uric acid

Question 14

Acute gout symptoms

Answer 14

• Podagra (pain arthritis of big toe) from crystal depostion
• meat or alcohol consumption can precipitate arthritis

Question 15

Chronic gout symptoms

Answer 15

• presence of tophi–chalky aggregates of urate crystals, with fibrosis and giant cell reaction in soft tissue/joints
• renal failure (uric acid crystals deposit in tubules)

Question 16

Tophi

Answer 16

• seen in chronic gout
• white, chalky aggregates of urate crystals
• with fibrosis and giant cell reaction in soft tissue and joints

Question 17

Gout:

-what do you see in synovial fluid?

Answer 17

• crystals, needle shaped
• have negative birefringence under polarized light
• “when crystals lay low (flat), they are yellow”

“yellow, parallel, allopurinol”

Question 18

Pseudogout:

-what do you see in synovial fluid?

Answer 18

• crystals, rhomboid shaped
• (CPPD) calcium pyrophosphate dihydrate
• weakly positive birefringence under polarized light

Question 19

DIP is spared in what joint disease?

Answer 19

RA. unlike OA, which affects both DIP and PIP

Question 20

What disease has DIP as the joint most commonly affected?

Answer 20

Psoriatic arthritis (sausage fingers)

Question 21

“can’t see, can’t pee, can’t climb a tree”

Answer 21

-Reiter’s syndrome (reactive arthritis)

Question 22

DIP and PIP are both affected in what joint disease?

Answer 22

OA. in RA, DIP is spared.

Question 23

how do gout crystals cause inflammation?

Answer 23

Phagocytosed MSU crystals induce monocyte to release IL1

Question 24

what body part does pseudogout most commonly affect?

Answer 24

• knee
• also other larger joints: wrist, shoulder

Question 25

What is CCP?

Answer 25

• Anti-cyclic citrullinated peptide
• measure this to diagnose RA. Better than Rheumatoid factor because sometimes RA has negative RF

Question 26

Caplan’s syndrome

Answer 26

• combination of RA and pneumoconiosis (lung disease caused by dust inhalation)
• presents with lung nodules on xray

Question 27

subchondral cyst

Answer 27

In OA, bone/cartilage breaks allowing synovial fliud into subchondral space, forming cysts.

Question 28

osteoarthritis: what do you see in synovial fluid?

Answer 28

• typically viscous and translucent, non-inflammatory WBC count (<2000/mm3)
• basically, you aspirate to exclude inflammatory causes of arthritis