Synovial Fluid

Question 1

Formation of synovial fluid

Answer 1

Plasma ultrafiltrate through loose synovial membranes and secretions of synoviocytes

Question 2

Composition of synovial fluid compared to plasma

Answer 2

Close to plasma: electrolytes, uric acid, glucose
1/3 of plasma: protein, immunoglobulins

Question 3

What is the lubricant that makes synovial fluid viscous?

Answer 3

Hyaluronate

Question 4

Normal synovial fluid values

Answer 4

Volume: <3.5
Viscosity: high
Clarity: clear
Color colorless/straw
WBC: <150
Polys%: <25
Gram stain: -

Question 5

Noninflammatory joint disorder (category I) values

these are degenerative

Answer 5

Volume: >3.5
Viscosity: high
Clarity: clear
Color: straw/yellow
WBC: <1000
Polys%: <25
Gram stain: -

Question 6

Inflammatory (category 2) joint condition values

these are crystal induced or have immunologic origin

Answer 6

Volume: >3.5
Viscosity: low
Clarity: cloudy
Color: yellow
WBC: 5k-75k
Polys%: 50-70
Gram stain: -

Question 7

Septic (category 3) joint disorder values

Answer 7

Volume: >3.5
Viscosity: mixed
Clarity: opaque
Color: mixed
WBC: >50,000
Polys%: >70
Gram stain: often +

Question 8

Collection process is called

Answer 8

Arthrocentesis

Question 8

Hemorrhagic (category 4) joint disorder values

caused by trauma or coag defic.

Answer 8

Volume: >3.5
Viscosity: low
Clarity: mixed
Color: red
WBC: similar to blood
Polys%: ^
Gram stain: -

Question 9

Purpose and method of mucin clot test

Answer 9

Synovial fluid easily contaminated by others
- Mucin clot test makes a dilution with acetic acid
- If it clots, then it is confirmed synovial

Question 10

Things that make synovial fluid cloudy

Answer 10

WBCs, red cells, synoviocytes, crystals, fat, fibrin, debris, ortho shards

Question 11

2 general things that cause decreased viscosity

Answer 11

1. Decreased synthesis of hyaluronate
2. Breakdown of hyaluronate (inflammation

Question 12

Clotting of synovial fluid

Answer 12

Always abnormal, fibrinogen present
- Membrane damage or traumatic tap

Question 13

Increased protein causes and significance

Answer 13

Causes: increased membrane perm., increased synthesis
Significance: RA, septic arthritis, crystal damage

Question 14

Glucose changes in values

Answer 14

Decreased values abnormal
- Difference between blood and synovial >20 mg/dl: possible sepsis
- If the difference is <20 mg/dl: infection not likely

Question 15

Uric acid and lactate in chemical analysis

Answer 15

Increased uric acid in gout in both fluid and serum

Increased lactate in septic arthritis, anaerobic glycolysis during inflammatory process

Question 16

Normal cell diff

Answer 16

60% monos/macros
30% lymphs
6% neutrs
4% synovial lining cells

Question 17

Increased PMNs causes

Answer 17

bacterial infection
gout, late RA

Question 18

Increased monos causes

Answer 18

Crystal induced arthritis, serum sickness

Question 19

Increased lymphocytes causes

Answer 19

Acute RA stages

Question 20

Crystal formation and analysis

Answer 20

Formation: affected by temp, pH, time

Polaraized miccroscopy shpws the colors with compensator plate

Question 21

Monosodium urate crystals

Answer 21

Gouty arthritis
Needle is pointy, negatively bifringent
Parallel: yellow

Perpendicular: blue

Question 22

Calcium pyrophosphate dihydrate crystals

Answer 22

Pseudogout from breakdown of cartilage, degenerative arthritis or caused by thyroid problems/diabetes

Small, blunt ends
Weal positive birefringence

Parallel: blue
Perpendicular: yellow

Question 23

Other crystals found in synovial fluid

Answer 23

• Cholesterol: chronic inflamm conditions
• Apatite: arthritic conditions
• Hydroxyapatite: acute inflamm reaction
• Corticosteroid: post intra articular injection

Question 24

Lyme arthritis pathogen and process

Answer 24

Untreated Lyme disease develops arthritis sometimes, large joints

• Borrelia burgdorferi

Question 25

Gout vs. Pseudogout

Answer 25

Gout: metabolic disorder w increased serum/joint uric acid, MSU crystals
Pseudogout: degenerative disorder, increased serum calcium, CPPD crystals