Synovial Fluid Flashcards
what cells line joints, tendon sheaths, and bursa?
synoviocytes
what cells are primarily in synovial fluid?
non-phagocytic mononuclear cells
low cellularity
what do synoviocytes type B secrete?
hyaluronate
how viscous is synovial fluid?
high viscosity
what are some indications for fluid analysis on synovial fluid?
joint effusion
lameness
fever of unknown origin
trauma/lacerations
what color is healthy synovial fluid?
colorless to pale straw
clear
what is bloody synovial fluid usually?
artifact of collection
when might synovial fluid clot?
blood contamination
intraarticular hemorrhage
protein exudation
what can cause decreased viscosity of synovial fluid?
inflammatory or non-inflammatory diseases
hyaluronidase produced by bacteria
enzymes released from inflammatory cells
dilutional effects of an effusion
dilution with excess anticoagulant
what do we analyze in synovial fluid?
physical features
total nucleated cell count
total protein determination
microscopic examination
do cell counts vary a lot in synovial fluid?
yes: between animals and even between joints
how can you estimate a cell count on a direct smear?
average number of cells per field multiplied by the objective power squared
can eosinophils or mast cells be in healthy synovial fluid?
no
what are the categories for synovial fluid analysis (abnormal)?
non-inflammatory arthropathy
mild, mixed inflammation
inflammatory arthropathy
hemarthrosis
what does non-inflammatory arthropathy result from?
trauma or degenerative changes in articular surfaces
what is cellularity usually in non-inflammatory arthropathy?
usually normal or mildly increased
predominance of mononuclear cells
when might cartilage fragments and osteoclasts be found in non-inflammatory arthropathy?
if damage to articular cartilage is severe enough and osteoid is exposed
what is cellularity in mild mixed inflammation?
above normal, generally <10,000/microliter
what is the cellularity in inflammatory arthropathy?
moderate to marked increase: >10,000/microliter
often 100,000-200,000/microliter
how prevalent are neutrophils in inflammatory arthropathy?
40-100% of the nucleated cells
what is the main differential in small animals for inflammatory arthropathy?
non-infectious arthropathies
what are non-infectious arthropathies often caused by?
immune-mediated disease
what are ragocytes?
neutrophils with phagocytized immunocomplexes or nuclear chromatin
what is the main differential for inflammatory arthropathy in large animals?
septic arthritis
