Synovial fluid analysis

Question 1

What is the normal amount of fluid in a small vs. large joint?

Answer 1

small <0.5 mL

Large <1 mL

Question 2

Pale yellow joint fluid in a horse is abnormal. T/F?

Answer 2

FALSE (normal)

Question 3

What does yellow, yellow/orange, and red jt fluid indicate?

Answer 3

yellow= cells, crystals

yellow-orange= RBC breakdown

red= hemorrhage

Question 4

What could make cloudy joint fluid?

Answer 4

cells

fibrin

crystals

Question 5

Why would the viscosity be decreased in joint fluid?

Answer 5

WBC/bacteria breakdown mucin d/t proteases

Dilution

decrease production from synovium damage

Question 6

Would you expect this joint to have normal jt fluid viscosity?

Answer 6

No, decrease eosinophilic background (= less mucin)

Question 7

What is the normal protein concentration in joint fluid?

Answer 7

< 2.5 g/dL

Question 8

What is the normal nucleated cell counts in jt fluid?

Answer 8

<3,000 (dogs, but rest of species lower)

Question 9

What cell type should dominate in jt fluid?

Answer 9

mononuclear cells (>90%) (phagocytes, lymphs)

NT (<10)

Question 10

Normal or abnormal cell in joint fluid?

Answer 10

synovial lining cells (clasmatocyte)

normal in joint fluid

Question 11

What is the predominant cell type in inflammatory vs. non-inflammatory abnormal joint fluid?

Answer 11

inflammatory: NT

non-inflammatory: mononuclear cells (but too many or extremely reactive)

Question 12

Differentials for non-inflammatory abnormal jt fluid?

Answer 12

DJD

trauma

hemoarthrosis

neoplasia

Question 13

Differentials for an Inflammatory neutrophilic joint fluid?

Answer 13

infectious

immunologic

nonimmunologic

Question 14

What is the most common cause of a non-inflammatory joint fluid? What diagnostic would likely be performed after the joint tap?

Answer 14

DJD

radiographs

Question 15

With hemarthrosis, NT can be common but not greater than 50%. T/F?

Answer 15

TRUE

Question 16

Inflammatory or not?

Type?

What do the vacuoles in the macrophages indicate?

Answer 16

Non-inflammatory (mononuclear dominant)

hemoarthrosis

inflammation

Question 17

Which type of dogs will get neoplasia in the joints?

Answer 17

middle age, large breed, large joint

Question 18

Top three neoplasia primary in joint?

Answer 18

histiocytic sarcoma

synovial cell sarcoma

synovial myxoma

Question 19

Inflammatory or not?

Type?

What is the pink material?

Answer 19

Non-inflammatory

neoplastic

osteoid

Question 20

What unique characteristic is seen with inflammatory joint fluid?

Answer 20

windrowing of NT

Question 21

Inflammatory or not?

septic or not?

Answer 21

Inflammatory

septic (intracellular bacteria)

Question 22

Why is it difficult to diagnose septic joint on cytology?

Answer 22

NT can have significant karyolysis making it look like a macrophage

bacteria predominately marginated on synovium and not in fluid***

Question 23

Differentials for infectious inflammatory jt fluid?

Of which of the ddx could also be associated with immunologic inflammatory jt fluid?

Answer 23

bacterial (sepsis)

viral, fungal, protozoal, tick-borne, mycoplasma (L form)

BOLD= immunologic also

Question 24

If you do not see bacteria in joint fluid, it is not septic. T/F?

Answer 24

FALSE

Question 25

Likely dx?

Answer 25

morula inside NT= anaplasma phagositophilum & erlichia eungii

Question 26

This kitten presents after a recent vaccination with calicivirus (MLV). He has a fever and joint stiffness + pain. What is your recommendation?

Answer 26

Pain medications & will resolve on own aka transient arthropathy

Question 27

What are the most common causes of reactive non-erosive immunologic, inflammatory jt dz?

Answer 27

chronic infection drug/vax enteropathy neoplasia

Question 28

What is the most common cause of non-erosive polyarthropathy in the canine?

Answer 28

Idiopathic

Question 29

What immunologic inflammatory condition is associated with CCL rupture?

Answer 29

lymphoplasmacytic

Question 30

What are the differentials for erosive immunologic, inflammatory joint disease?

Answer 30

Idiopathic (rheumatoid) Erosive polyarthritis of greyhounds (EPG) Feline chronic progressive polyarthritis (FCPP)

Question 31

In what canine breeds is idiopathic erosive inflammatory disease most common aka rheumatoid arthritis?

Answer 31

toy & small breeds

Question 32

A greyhound presents with joint pain and stiffness in multiple joints and also has a cough. Likely DDX?

Answer 32

Erosive polyarthritis of greyhounds (EPG) also associated with pneumonia

Question 33

What gender of felines is more commonly associated with Feline chronic progressive polyarthritis?

Answer 33

males

Question 34

What viruses are commonly associated with Feline chronic progressive polyarthritis?

Answer 34

FeSFV & ?FeLV

Question 35

What DDX for non-immunologic inflammatory jt disease?

Answer 35

necrotic neoplasia Pseudogout (very rare)