The value of synovial fluid assays in the diagnosis of joint disease: a literature survey

Abstract

Objective: To carry out a critical appraisal of the literature in an attempt to assess the current value of synovial fluid (SF) analysis in the diagnosis of joint disease. Methods: A literature search was undertaken using the Medline, Biomed, Bids, Pubmed, and Embase electronic databases using the keywords: synovial fluid (SF) analysis, SF crystals, joint sepsis, acute arthritis, and SF cell counts, cytology, biomarkers, and microbiology. Results: Publications fell into three main categories. Firstly, reports assessing the value of the three traditional assays (microbiology, white blood cell counts, and microscopy for pathogenic crystals). For these quality control evidence was found to be sparse, and tests for sensitivity, specificity, and reliability showed worrying variations. These poor standards in SF analysis may be due to lack of inclusion of some tests within routine pathology services. Secondly, claims for the usefulness of "new" assays (cytology and biochemical markers). For cytology, the supporting evidence was mainly anecdotal and there were no reports on specificity, sensitivity, and reliability. Interpretation difficulties are a major hindrance to the clinical use of biochemical assays, which remain primarily research tools. Finally, work on the diagnostic value of SF analysis in general. The appraisal confirmed that SF analysis remains of major diagnostic value in acute arthritis, where septic arthritis or crystal arthropathy is suspected, and in intercritical gout. Conclusions: Given the importance of SF tests, rationalisation of their use, together with improved quality control, should be immediate priorities. Further investigation is recommended into the contribution of SF inspection and white cell counts to diagnosis, as well as of the specificity and sensitivity of SF microbiological assays, crystal identification, and cytology.

Study of inflammatory markers in idiopathic osteoarthritis of knee

“…Further investigation is recommended into the contribution of SF inspection and white cell counts to diagnosis, as well as of the specificity and sensitivity of SF microbiological assays, crystal identification, and cytology. 5 SF analysis was most useful for patients likely to have gout, pseudogout, or infectious arthritis. The derived therapeutic thresholds were consistent with recommended medical practice, for example, with a lower threshold for possible septic arthritis (20%) than for possible gout (65%).…”

Hematogenous Septic Ankle Arthritis

“…Synovial fluid analysis for cell count, Gram stain, and culture is the fundamental diagnostic tool for septic arthritis [15]. Staphylococci and streptococci are identified in the literature as the offending organisms in the majority of joint infections [1,2,4,5,8].…”

Dual Energy CT: added value in gouty arthritis

“…Gout is a disease that occurs as a response to monosodium urate crystals deposition in periarticular soft tissue, joints and subchondral bone with secondary destruction of joints 85%, the reliability of the analyses has been questioned (7,8).…”