SYNOVIAL FLUID Flashcards
Synovial fluid is also known as?
Joint fluid
It is a viscous liquid found in the cavities of the movable joints (diarthroses) or synovial joints
Synovial fluid
Functions of synovial fluid:
- Lubricate joints
- Reduce friction between bones
- Provides nutrients to the articular cartilage
- Lessen shock of joint compression occurring during activities such as walking and jogging
Masakit sa arthritis =
Watery synovial fluid
It is the polymerization of hyaluronic acid
viscosity
Decrease of synovial fluid viscosity =
arthritis
Method of collection for synovial fluid
arthrocentesis
Normal synovial fluid does not ________
Clot (diseased joint may clot)
Synovial fluid
Normal volume in adult knee cavity =
Inflammation =
<3.5 mL
>25 mL
SF:
Colorless - pale yellow (clear) =
normal
SF:
Deeper yellow =
inflammation
SF:
Greenish tinge
Bacterial infection
SF:
Red =
Traumatic tap, hemorrhagic arthritis
SF:
Turbid =
WBCs, synovial cell debris, fibrin
SF:
Milky =
Presence of crystals
SF:
Plain red top tube (no anticoagulant) =
Chemical and immunologic evaluation
SF microscopic examination:
Sodium Heparin/ liquid EDTA =
Hematology or cell count
SF microscopic examination:
Do not use ________ and _________
Do not _______ samples
Powdered anticoagulants
Lithium heparin
refrigerate
SF:
Sterile anticoagulant tube ( heparin or SPS) =
Microbiological studies (GS and culture)
Synovial fluid viscosity normal value =
Forms a string that is 4-6 cm long
Test for SF viscosity
Ropes or Mucin Clot test (Hyaluronate Polymerization test)
Ropes or Mucin clot test:
Reagent =
Positive reaction (hyaluronic acid + acetic acid) =
2-5% acetic acid
Mucin clot
Grading for SF viscosity:
Good =
Fair =
Low =
Poor =
Solid or compact clot, clear solution
Soft clot
Priable clot, cloudy solution
No clot
Most frequently performed count in synovial fluid
WBC count
SF WBC count diluting fluids:
NSS with methylene blue
Hypotonic saline (0.3%)
Saline with saponin
Differential count of cells in SF:
Rbcs =
WBCs =
WBC differential =
<2,000/uL
< Or = 200/uL
65% = monocytes and macrophages
25% = neutrophils
15% = lymphocytes
For every viscous liquid in SF:
- add a pinch of hyaluronidase to ____________ or add 1 drop of _______________ in phosphate buffer per mL of fluid
- incubate at ________________ for ___________
0.5 mL
0.05% hyaluronidase
37° C
5 min.
Cells and inclusions seen in SF:
Polymorphonuclear leukocytes = bacterial sepsis, crystal- induced inflammation
Neutrophils (3 lobes)
Mononuclear leukocyte = nonseptic inflammation
lymphocyte
Large mononuclear monocyte, may be vacuolated = normal, viral infections
macrophages
Neutrophils ingested “round body” = lupus erythematosus
LE cell
Vacuolated macrophage with ingested neutrophils = reactive arthritis
Reiter cells
Neutrophils with dark cytoplasmic granules containing precipitated rheumatoid factor = rheumatoid arthritis, immunologic inflammation
RA cell
Morphologically resembles polished rice = tuberculosis, septic, and rheumatoid arthritis
Rice bodies
Debris from metal and plastic joint prosthesis “ground pepper appearance” = ochronotic arthropathy, alkaptonuria, ochronosis
Ochronotic shards
Large, multinucleated cells = osteoarthritis
Cartilage cells
Similar w/ macrophage, but may be multinucleated, resembling a mesothelial cell = normal, disruption from arthrocentesis
Synovial lining cell
Refractive intracellular and extracellular globules = traumatic injury, chronic inflammation
Fat droplets
Inclusions w/in clusters of synovial cells = pigmented villonodular synovitis
hemosiderin
Normal synovial fluid should _________ contain any crystal
not
Cause of crystal formation in SF:
- Metabolic disorders
- Decreased renal excretion that produces increased blood levels of crystallizing chemicals
- Degeneration of cartilage and bones
- Injection of medications (corticosteroid)
Most common
Needles
- birefringe
gout
Monosodium urate
Rhombic square, rods
Most common
+ Birefringe
Pseudogout
Calcium pyrophosphate
Notched, rhombic plates
- birefringe
extracellular
Cholesterol
Flat, variable-shaped plates
+ And - birefringes
Injections
Corticosteroid
Envelopes
- birefringe
Renal dialysis
Calcium oxalate
Small particles, requires electron microscopy
- birefringe
Osteoarthritis
apatite
Detects the presence or absence of birefringes
Polarizing microscope
Confirm the type of birefringence (+ or -)
Red compensator is placed between crystal and analyzer
Compensated polarizing microscope
- birefringes
Yellow color
Parallel to long axis
Monosodium urate
+ birefringes
Blue color
Perpendicular to long axis
Calcium pyrophosphate dihydrate (CPPD)
