4. Synovial Fluid
Viscous fluid found in the
cavities of movable joints
(diarthroses)
Synovial membrane
Inner membrane of
synovial joints
Secretes synovial fluid
into the joint cavity
Contain specialized cells
(synoviocytes)
5. Composition
Hyaluronic acid
synthesized by the synovial membrane
increase the viscosity and elasticity of articular
cartilages
lubricate the surface between synovium and
cartilage.
Lubricin secreted by synovial cells.
It is chiefly responsible for so called boundary
layer lubrication, which reduces friction between
opposing surfaces of cartilage.
6. What do you call the damage
to the articular membranes
producing stiffness and pain in
the joints?
12. Bulge test
The Bulge test is used to determine if there is an
abnormal amount of fluid surrounding a joint
Bulge test of joint for the detection of synovial effusion
17. Macroscopic Analysis: Color and Clarity
Colorless to pale yellow and clear
normal
Red, brown, or xanthochromic
hemorrhage into the joint
Yellow/clear
noninflammatory effusions
Yellow/cloudy
inflammation
White/cloudy/milky
Crystals
Deeper yellow
Non inflammatory and inflammatory effusions
18. Macroscopic Analysis: Inclusions
Rice bodies.
Free-floating aggregates of tissue appear as
rice bodies.
rheumatoid arthritis (RA)
Degenarated synovium enriched with
fibrin
Ochronotic shards
debris from joint prosthesis
look like ground pepper
A =ochronotic shards
B =rice bodies
19. Macroscopic Analysis: Viscosity
“Ropes” or “Mucin
Clot Test”
Normal = 4-6 cm
When 2-5% acetic acid
is added, normal
synovial fluid will form
a clot surrounded by
clear fluid
20. A medical technologist received 2 clear,
thick and viscous samples labelled A
and B. He added 2% acetic acid, sample
A did not clot while sample B did.
Which of the following is suggestive of
synovial fluid? The other sample may
possibly be?
21. When sufficient blood is collected,
it should be distributed in what
color of tubes?
23. Macroscopic Analysis: Clotting
Normal synovial fluid: Do not clot
Clotting of synovial fluid = fibrinogen
1.Damaged synovial membrane
2.Traumatic tap
24. Macroscopic Analysis: Mucin Clot
“Ropes test”
Estimation of hyaluronic acid–
protein complex integrity
The adding of acetic acid to
normal synovial fluid, which
causes clot formation.
Criteria:
Compactness of the clot
Clarity of the supernatant fluid
25. Mucin Test
Good : solid clot
Fair: soft clot
Low: Friable clot
Poor: No clot
26. Macroscopic Analysis: Cell Counts
Total leukocyte count
<200 cells/uL
Very viscous fluid
Pinch of hyaluronidase + 0.5 ml fluid
1 gtt 0.05% hyaluronidase in phosphate buffer per ml of
fluid (incubate 37oC for 5 minutes)
32. Macroscopic Analysis: Diff Count
Incubate with hyaluronidase
Neutrophils : <25% of the differential
Lymphocytes: <15%
Crystal: None present
Increase neutrophil: septic condition
Increase cell count with increase lymphocyte:
nonseptic inflammation
33. Chemical Analysis: Protein
All proteins found in plasma
Exception: various high–molecular weight
proteins which may be present in very small
amount
Fibrinogen
beta 2 macroglobulin
alpha 2 macroglobulin
Use common serum protein procedures
34. Chemical Analysis: Protein (cont.)
Normal range <3 g/dl
Increased protein
ankylosing spondylitis
arthritis
Crohn disease
Gout
Psoriasis
Reiter syndrome
ulcerative colitis.
35. Chemical Analysis: Glucose
Compare to serum glucose levels
<10 mg/dL lower than blood glucose
Decreased – joint disorders
>20mg/dl decrease - infection
37. Chemical Analysis: Lactic Acid
Rarely measured in synovial fluid
Can be helpful in diagnosing septic arthritis.
Normal = less than 25 mg/dL
Septic arthritis can show levels up to 1000 mg/dL
38. Laboratory Testing: Lactate Dehydrogenase
Elevated in synovial fluid
Normal in serum level
Increased in
Rheumatoid arthritis
(RA)
infectious arthritis
gout
Neutrophils increased
during the acute phase of
these disorders contribute
to this increased LD.
39. Laboratory Testing: Rheumatoid Factor
RF is an antibody to immunoglobulins.
Present in rheumatoid arthritis:
Serum – most cases
Synovial fluid - 50%
Rarely elevated only in synovial fluid and not
serum
False positives in other chronic inflammatory
diseases.
40. Microscopic Analysis: Differential
LE cells
Neutrophils that have
engulfed a nucleus of
a lymphocyte
Tart cells
Monocytes that have
engulfed nuclear
material
41. Microscopic Analysis: Differential
Reiter cells
Vacuolated macrophages
with ingested neutrophils
RA cells
“Ragocytes”
Neutrophils with small,
dark, cytoplasmic
granules that consist of
precipitated rheumatoid
factor
42. Microscopic Analysis: Differential
Hemosiderin
Seen in Pigmented
Villonodular Synovitis
Inclusions within clusters
of synovial cells
Rice bodies
Macroscopically resemble
polished rice
Macroscopically show
collagen and fibrin
47. Laboratory Testing: Microbiology
Staining
Smears prepared by centrifugation or
cytocentrifugation
Saline dilution reduces clustering of cells
Gram’s stain most common
Culture
Set up with positive or negative stain results
Aerobic
anaerobic
54. Laboratory Findings
4. Hemorrhagic
Cloudy, red fluid
Low viscosity
WBCs equal to blood
Neutrophils equal to blood
Normal Glucose level
55. Review of Key Points
Synovial fluid analysis
Is a well-established procedure for evaluation of joint
disease.
Determines the presence of arthritis
Assists in the classification of joint disorders
Helps guides appropriate treatments