Useful For
Synovial fluid is basically an ultrafiltrate of plasma combined with a mucopolysaccharide (hyaluronate) that is synthesized by the cells of the synovial membrane. The functions of the synovial fluid are to lubricate the joint space and transport nutrients to the articular cartilage. Various disorders produce changes in the chemical constituents of the joint fluid and in the type of cell population present. The five major disease categories are non-inflammatory, inflammatory, infectious, crystal-associated, and hemorrhagic.
Method Name
Manual or Impedance Count
Aliases
Cell Count, Synovial Fluid; Joint Fluid; Crystals, Cell Count - Synovial Fluid
Specimen Type
Specimens should be collected in EDTA tubes. Examination for crystals should be carried out as soon as possible as false positive or negative results may result. Total cell counts should be performed within 4 hours of collection. If the specimen cannot be tested immediately, refrigeration will help to maintain morphologic features for smears for up to 24 hours.
Specimen Required
One lavender top (EDTA) tube.
Specimen Minimum Volume
0.5 mL of fluid
Specimen Stability Information
4 hours at room temperature or 24 hours refrigerated.
Rejected Due To
- Clotted
- >4 hours old and has not been refrigerated.
- <0.5 mL submitted.
Special Instructions
Cell counts cannot be performed on clotted fluids.
Performing Laboratory
As ordered. Turn around time is 4 hours.
Reference Values
See report
Day(s) and Time(s) Performed
Monday – Friday, 24 hours/day
Analytical Time
1-2 hours
Specimen Retention Time
2 days
CPT Code Information
89051, 89060
Analytical Time
1-2 hours