The document discusses the physiology, composition, and testing of synovial fluid, which is found in movable joints and plays critical roles in lubrication, reducing friction, and supplying nutrients. It details specimen collection methods, macroscopic and microscopic evaluation, and chemical analysis of synovial fluid, along with diagnostic implications for various joint disorders. Additionally, it classifies joint disorders based on their pathologic significance and highlights the importance of synovial fluid analysis in diagnosing conditions like arthritis.

1. Muhammad Asif Zeb
Lecture Hematology
IPMS-KMU

2. Objective
Physiology and Composition of Synovial Fluid
Specimen Collection
Laboratory Testing
Macroscopic Evaluation
Chemical Examination
Microscopic Examination

3. Synovial Fluid
Synovial
syn(like) + ovia (egg)
“Joint Fluid”

4. Synovial Fluid
Viscous fluid found in the
cavities of movable joints
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.

7. Major Functions
Reducing friction
Lubrication
Lessen shock
Supplying oxygen and
nutrients

10. Synovial Fluid:
Specimen Collection

11. 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

12. Bulge Test

13. Specimen Collection
Arthrocentesis
Placement of needle in arthrocentesis of (A) elbow and
(B) knee joints.

14. CollectionThree samples are collected.
Note
If the specimen cannot be examined immediately, fluid should be frozen
and stored at -70°C until examined

15. Macroscopic Laboratory
Testing
Volume
Color and Clarity
Inclusions
Viscosity
Clotting
Mucin Clot

16. Laboratory Testing: Macroscopic
Volume
Normal up to <3.5 ml of fluid
Can reach up to 25 ml
Inflammation

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

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

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. Macroscopic Analysis: Clotting
Normal synovial fluid: Do not clot
Clotting of synovial fluid = fibrinogen
1.Damaged synovial membrane
2.Traumatic tap

21. 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

22. Mucin Test
Good : solid clot
Fair: soft clot
Low: Friable clot
Poor: No clot

23. Microscopic Analysis: Cell Counts
Total leukocyte count
<200 cells/uL

24. Why is the traditional WBC
fluid not used for cell counting?

25. Because it contains
______________ which is
responsible for clotting.

26. Can clear undiluted fluid be
used for counting?

27. Microscopic Analysis: Cell
Counts
Neubauer Counting Chamber

28. Microscopic 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

29. 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

30. Chemical Analysis: Protein (cont.)
Normal range <3 g/dl
Increased protein
ankylosing spondylitis
arthritis
Crohn disease
Gout
Psoriasis
Reiter syndrome
ulcerative colitis.

31. Chemical Analysis: Glucose
Compare to serum glucose levels
<10 mg/dL lower than blood glucose
Decreased – joint disorders

32. Chemical Analysis: Uric Acid
Normal - 6 to 8 mg/dL
Increased – gout
May form crystals

33. 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

34. 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.

35. 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.

36. Microscopic Analysis: Differential
LE cells
Neutrophils that have
engulfed a nucleus of
a lymphocyte
Tart cells
Monocytes that have
engulfed nuclear
material

37. 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

38. Microscopic Analysis: Differential
Hemosiderin
Seen in Pigmented
Villonodular Synovitis
Inclusions within clusters
of synovial cells
Rice bodies
Macroscopically resemble
polished rice
Microscopically show
collagen and fibrin

39. Crystal Identification
Monosodium urate (MSU)
Calcium pyrophosphate (CPPD)

40. Crystal Identification
Corticosteroid
Cholesterol

41. 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

42. Classification of Joint Disorders

43. Classification of Joint Disorders
Group Classification Pathologic Significance
1. Noninflammatory Degenerative joint
disorders, osteoarthritis
2. Inflammatory Immunologic Disorders,
RA, Scleroderma,
Polymyositis, ankylylosing
spondylitis, rheumatic
fever, Lyme arthritis,
Crystal-induced gout,
pseudogout

44. Classification of Joint Disorders
3. Septic Microbial Infection
4. Hemorrhagic Traumatic injury, tumors,
hemophilia, other coagulation
disorders, anticoagulant overdose

45. 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

46. Thank you