Synovial Fluid Flashcards
Where is a synovial fluid produced?
Tissue: Synovium
Role of synoviocyte
Active phagocytes and synthesize hyalaurate
Synovial fluid is formed by…
the ultrafiltration of plasma across the synovial membrane
Viscous fluid in joints
sole nutrient source for the metabolically active articular cartilage
In the fasting patient, compare synovial fluid and plasma
Equivalent: glucose and uric acid
Physical of synovial fluid: Color
Normal: Colorless - Slightly pale yellow Class 1: Pale yellow: non-inflammatory Class 2: Deep yellow: Inflammatory Hemorrhagic: Red Bacterial infection: Green tinge
Physical of synovial fluid: Clarity
Normal: translucent WBC or Synovial cell debris: turbid Crystal: milky, opaque Fibrinogen: clotting Fractured joint: Fat on side/on top of bloody layer Necrotic tissue: Rice body
Physical of synovial fluid: Texture
Normal: Egg white
Arthritis: decreased viscosity
Pus: purulent (septic arthritis –> shake to see if clots are present)
Cholesterol: purulent if high conc.
White sodium urate crystals: opaque gouty effusion (chronic gouty arthritis)
Synovial fluid sample collecting
Arthrocentesis
Handling sample of SF
Remove needle first –> Record: color, clarity –> Check volume for next steps tests
Tube for Synovial
Liquid anticoagulant (Sodium heparin/Green top) EDTA (lavender), Citrate (blue) Other chemistry tests (red)
Synovial Fluid Classification
G1: Non-inflammatory
G2: Inflammatory
G3: Septic (bacterial infection)
Hemorrhagic
Symmetrical arthritis
The same joints are affected both sides –> Inflammatory
Asymmetrical arthritis
Only one side –> a degenerative or non-inflammatory arthritis
Degenerative arthritis
the breakdown of cartilage
Erosion
breakdown of bone (of joints)
Osteoarthritis
Non-inflammatory, asymmetrical.
Spongy cushions of cartilage, “wear and tear” (bones of joints rub together)
Morning stiffness relieve less than 30 min
Reason: heredity, obesity, overuse, age
Treatment: chiropractor, water exercise, physical therapy
Rheumatoid arthritis
Inflammatory, symmetrical
Morning stiffness lasts longer than 30 min
Red, swollen, painful –> lead to permanent deformity & erosion
The body immune system attacks synovium lining
No cure, use pain reliver.
Infectious (septic)
Caused by Staph., TB
The spread from open wounds, surgery, bites, etc.
Treatment: antibiotics, tissue removal. fluid drainage
Hemorrhage
Bleeding to the joints (can be caused by tumor)
Occur after injuries, surgical procedures
Bleeding causes damage to synovium, cartilage,
Treatment: Draining blood, synovectomy, or drug for clotting factor
Calcium Pyrophosphate Dihydrate (CPPD)
- Rod, square with blunt, angulated ends
- Weakly birefringent (blue parallel)
- Examined under a polar microscope (compensator to have dark background)
- Found in pseudogout (caused by CPPD instead of urate crystal), degenerative arthritis: cartilage calcification and elevated calcium levels.
Monosodium urate (MSU)
- Fine, needle-shape, rod-shape
- Negative birefringent (yellow parallel)
- Wet mount (the best examination) or Wright stained slide
- Disease: Gout, impaired metabolism of purines, high purine diet, alcohol, chemotherapy
Calcium oxalate
Bipyramid shaped
No birefringent
Rare to see in synovial fluid
Corticosteroids
Rod-shaped and aggregates present
Variable birefringent
Mostly be injected into the joint, but can be confused with pathological
Cholesterol
Flat, square, notch corner
No birefringent
Seen in chronic inflammation and inflammatory effusion
Milky/white specimens can indicate
Calcium phosphate
Requires electron microscopy as it’s very tiny
Rod-shaped
Not birefringent
Seen in osteoarthritis (assoc. with calcified cartilage degeneration)
