Module UBF-12 · Version 1.0
Synovial Fluid and Crystal Examination
Work a synovial fluid aspirate from collection through compensated polarized light crystal identification. Evaluate specimen suitability, run the cell count and differential, and use shape, birefringence sign, and orientation to separate monosodium urate and calcium pyrophosphate crystals from look-alikes, without letting a crystal finding cancel a concurrent infection workup.
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Who this module is for
Medical laboratory scientists and students performing or reviewing body fluid microscopy who need a repeatable approach to synovial fluid triage and crystal identification.
Learning objectives
- Explain how collection tubes, clotting, viscosity, and time since collection affect which synovial fluid tests can be trusted.
- Classify gross appearance and inflammatory cell patterns cautiously, without turning either into a stand-alone diagnosis.
- Use crystal shape, birefringence sign, orientation to the compensator slow axis, and intracellular location to identify monosodium urate and calcium pyrophosphate crystals and separate them from look-alikes.
How completion works
Mark every required section done and answer every knowledge check in those sections correctly. The final save completes the module automatically.
Sources
12 sources
1. Jokic A, Kopcinovic LM, Culej J, et al. Laboratory testing of extravascular body fluids: National recommendations. Part II, Synovial fluid. Biochem Med (Zagreb). 2020;30(3):030501. doi:10.11613/BM.2020.030501.
Source note · peer-reviewed literature
2. Zell M, Zhang D, FitzGerald J. Diagnostic advances in synovial fluid analysis and radiographic identification for crystalline arthritis. Curr Opin Rheumatol. 2019;31(2):134-143. doi:10.1097/BOR.0000000000000582.
Source note · peer-reviewed literature
3. McCarty DJ, Hollander JL. Identification of urate crystals in gouty synovial fluid. Ann Intern Med. 1961;54:452-460. doi:10.7326/0003-4819-54-3-452.
Source note · peer-reviewed literature
4. Papanicolas LE, Hakendorf P, Gordon DL. Concomitant septic arthritis in crystal monoarthritis. J Rheumatol. 2012;39:157-160. doi:10.3899/jrheum.110571.
Source note · peer-reviewed literature
5. Luo TD, Jarvis DL, Tipton SC. Synovial cell count poorly predicts septic arthritis in the presence of crystalline arthropathy. J Orthop. 2020;18:112-117. doi:10.1016/j.jor.2019.10.017.
Source note · peer-reviewed literature
6. Clinical and Laboratory Standards Institute. H56-A: Body Fluid Analysis for Cellular Composition, 1st ed. Consensus standard, archived 2006.
Source note · consensus standard
7. Centers for Medicare & Medicaid Services. 42 CFR 493.1252, Standard: Test systems, equipment, instruments, reagents, materials, and supplies.
Source note · federal guidance
8. College of American Pathologists. Hematology, Coagulation, and Clinical Microscopy Checklist, HEM.35357 Body Fluid Analysis Procedure (Phase II). CAP Accreditation Program, 12.09.2025 edition.
Source note · accreditation standard
9. College of American Pathologists. Hematology, Coagulation, and Clinical Microscopy Checklist, HEM.35528 Body Fluid Cell Differentials (Phase I). CAP Accreditation Program, 12.09.2025 edition.
Source note · accreditation standard
10. College of American Pathologists. Hematology, Coagulation, and Clinical Microscopy Checklist, HEM.35650 Body Fluid Result Reporting of Nucleated Cells (Phase I). CAP Accreditation Program, 12.09.2025 edition.
Source note · accreditation standard
11. College of American Pathologists. Hematology, Coagulation, and Clinical Microscopy Checklist, HEM.35651 Crystal Morphology Assessment (Phase II). CAP Accreditation Program, 12.09.2025 edition.
Source note · accreditation standard
12. College of American Pathologists. Hematology, Coagulation, and Clinical Microscopy Checklist, HEM.35652 Criteria for Body Fluid Crystal Review (Phase II). CAP Accreditation Program, 12.09.2025 edition.
Source note · accreditation standard