|
Analyte/characteristics |
Normal |
Type I (noninflammatory) |
Type II (inflammatory) |
Type III (septic) |
|
Volume (mL; knee joint) |
<3.5 |
Often >3.5 |
Often >3.5 |
Often >3.5 |
|
Color |
Colorless or straw-colored |
Straw-colored or yellow |
Yellow |
Yellow-gray |
|
Transparency |
Completely transparent |
Completely transparent |
Slightly turbid or turbid |
Turbid |
|
pH |
7.2-7.4 |
7.2-7.4 |
7.1-6.8 |
6.6 |
|
Viscosity (cP) |
High (3-10) |
High (3-10) |
Decreased (<3) |
Varied |
|
Protein, total (g/dL) |
1.8-2.1 |
2.99 |
4.19 |
5.6 |
|
Glucose concentration |
As in serum |
As in serum |
Lower than in serum (difference <50 mg/dL) |
Significantly lower than in serum (difference >50 mg/dL) |
|
Ropes test |
Solid precipitate |
Solid precipitate |
Flocky precipitate |
Cloudiness |
|
Cells/mm3 |
<200 |
200-2000 |
2000-75,000 |
Often >100,000 |
|
Granulocytes (%) |
<25 |
<25 |
Often >50 |
>75 |
|
Bacteria (culture result) |
Negative |
Negative |
Negative |
Often positive |
|
Adapted from Ropes MW, Bauer W. Synovial fluid changes in joint disease. Harvard University Press; 1953. |
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|
cP, centipoise. |
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