• 1. 

    Neogi T, Jansen TL & Dalbeth N et al.: 2015 Gout classification criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative. Ann Rheum Dis 74 : 1789, 2015.

    • Crossref
    • PubMed
    • Web of Science
    • Search Google Scholar
    • Export Citation
  • 2. 

    Sivera F, Andres M & Falzon L et al.: Diagnostic value of clinical, laboratory, and imaging findings in patients with clinical suspicion of gout: a systematic literature review. J Rheumatol Suppl 92 : 3, 2014.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 3. 

    Schlesinger N: Diagnosis of gout: clinical, laboratory, and radiographic findings. Am J Manag Care 11 : S443, 2005.

  • 4. 

    Graf SW & Buchbinder, Zochling J et al.: The accuracy of methods for urate crystal detection in synovial fluid and the effect of sample handling: a systematic review. Clin Rheumatol 32 : 225, 2013.

    • Crossref
    • PubMed
    • Web of Science
    • Search Google Scholar
    • Export Citation
  • 5. 

    Lumbreras B, Pascual E & Frasquet J et al.: Analysis for crystals in synovial fluid: training of the analysts results in high consistency. Ann Rheum Dis 64 : 612, 2015.

    • Search Google Scholar
    • Export Citation
  • 6. 

    Pascual E, Batlle-Gualda E & Martinez A et al.: Synovial fluid analysis for diagnosis of intercritical gout. Ann Intern Med 131 : 756, 1999.

  • 7. 

    Wijnands JM, Boonen A & Arts IC et al.: Large epidemiologic studies of gout: challenges in diagnosis and diagnostic criteria. Curr Rheumatol Rep 13 : 167, 2011.

    • Crossref
    • PubMed
    • Web of Science
    • Search Google Scholar
    • Export Citation
  • 8. 

    Dalberth N, Schumacher HR & Fransen J et al.: Survey definitions of gout for epidemiological studies: comparison with crystal identification as the gold standard. Arthritis Care Res (Hoboken) 68 : 1894, 2016.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 9. 

    Houk JL: “Joint Fluid,” in Oxford Textbook of Rheumatology, 3rd Ed, ed by Isenberg, DA, Maddison, PJ & Woo, P et al, p 499, Oxford University Press, New York, 2004.

    • Search Google Scholar
    • Export Citation
  • 10. 

    Dieppe P & Swan A: Identification of crystals in synovial fluid. Ann Rheum Dis 58 : 261, 1999.

  • 11. 

    von Essen R, Holtta AM & Pikkarainen R. Quality control of synovial fluid crystal identification. Ann Rheum Dis 57 : 107, 1998.

  • 12. 

    Schumacher HR, Sieck MS & Rothfuss S et al.: Reproducibility of synovial fluid analysis: a study among four laboratories. Arthritis Rheum 29 : 770, 1986.

  • 13. 

    Lumbreras B, Pascual E & Frasquet J et al.: Analysis for crystals in synovial fluid: training of the analysts results in high consistency. Ann Rheum Dis 64 : 612, 2005.

  • 14. 

    Meyr AJ, Singh S & Zhang X et al.: Statistical reliability of bone biopsy for the diagnosis of diabetic foot osteomyelitis. J Foot Ankle Surg 50 : 663, 2011.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 15. 

    Guyatt G, Rennie D & Meade MO et al.: Users' Guides to the Medical Literature: A Manual for Evidence-Based Clinical Practice, 2nd Ed, McGraw-Hill, New York, 2008.

    • Search Google Scholar
    • Export Citation
  • 16. 

    Gordon C, Swan A & Dieppe PA: Detection of crystals in synovial fluids by light microscopy: sensitivity and reliability. Ann Rheum Dis 48 : 737, 1989.

  • 17. 

    Swan AJ, Chapman B & Heap P et al.: Submicroscopic crystals in osteoarthritic synovial fluids. Ann Rheum Dis 53 : 467, 1994.

  • 18. 

    Bjelle A, Crocker P & Willoughby D: Ultramicrocrystals in pyrophosphate arthropathy: crystal identification and case report. Acta Med Scand 207 : 89, 1980.

  • 19. 

    Dieppe P & Swan A: The Identification of Crystals in Synovial Fluid, University of Bristol, Bristol, England, 1998.

Level of Agreement with the Microscopic Analysis of Joint Aspirate for the Diagnosis of Gout in the Lower Extremity

View More View Less
Restricted access

Background

Although clinical findings, laboratory serum markers, and radiographic images are also used, the purported gold standard or standard reference test for the diagnosis of gout is microscopic analysis of aspirated joint fluid. This observational investigation sought to identify the level of agreement with the microscopic analysis of joint fluid aspirate for the diagnosis of gout in the lower extremity between two departments in a single health-care center.

Methods

A retrospective medical record review identified consecutive patients seen for suspected gout who underwent diagnostic joint aspiration. Patients were included if a lower-extremity joint synovial fluid sample was obtained and were excluded if they were not independently evaluated by both the departments of rheumatology and pathology. We categorized the documented joint fluid findings into four groups: no crystals, sodium urate crystals, calcium pyrophosphate dihydrate crystals, or both sodium urate and calcium pyrophosphate dihydrate crystals. We defined a “clinically significant disagreement” as one department observing any type of crystals and the other department observing no crystals.

Results

We observed a clinically significant disagreement rate of 23.26% (intraclass correlation coefficient = 0.496). The department of rheumatology was more likely to observe the presence of crystals in a sample compared with the department of pathology (88.37% versus 65.12%; P = .02).

Conclusions

These results provide evidence that microscopic analysis of joint fluid aspirate might lack the accuracy and reliability needed to be considered a gold standard diagnostic test for gout in the lower extremity.

Department of Rheumatology, Coordinated Health, Allentown, PA.

Temple University Hospital Podiatric Surgical Residency Program, Philadelphia, PA.

Department of Podiatric Surgery, Temple University School of Podiatric Medicine, Philadelphia, PA.

Corresponding author: Andrew J. Meyr, DPM, Department of Podiatric Surgery, Temple University School of Podiatric Medicine, 8th at Race St, Philadelphia, PA 19107. (E-mail: ajmeyr@gmail.com)