| Summary, etc. |
<h4 style="font-size: 13px; margin: 0px 0.25em 0px 0px; text-transform: uppercase; float: left; font-family: arial, helvetica, clean, sans-serif;"><span style="font-size: 10pt;">BACKGROUND:</span></h4><p style="margin: 0px 0px 0.5em; font-size: 1.04em; font-family: arial, helvetica, clean, sans-serif;"><span style="font-size: 10pt;">Rapid diagnosis of septic arthritis from Gram-stain microscopy is limited by an inherent false-negative rate of 25-78%. The presence of concomitant crystal arthritis in 5% of cases represents a particular diagnostic challenge.</span></p><h4 style="font-size: 13px; margin: 0px 0.25em 0px 0px; text-transform: uppercase; float: left; font-family: arial, helvetica, clean, sans-serif;"><span style="font-size: 10pt;">OBJECTIVE:</span></h4><p style="margin: 0px 0px 0.5em; font-size: 1.04em; font-family: arial, helvetica, clean, sans-serif;"><span style="font-size: 10pt;">This study aims to investigate the effects that a concomitant crystal arthropathy have on the ability of Gram-stain microscopy of synovial fluid to diagnose a septic arthritis.</span></p><h4 style="font-size: 13px; margin: 0px 0.25em 0px 0px; text-transform: uppercase; float: left; font-family: arial, helvetica, clean, sans-serif;"><span style="font-size: 10pt;">METHODS:</span></h4><p style="margin: 0px 0px 0.5em; font-size: 1.04em; font-family: arial, helvetica, clean, sans-serif;"><span style="font-size: 10pt;">This is a 12-year retrospective cohort study. Inclusion criteria were a positive synovial fluid culture result with a positive clinical diagnosis of septic arthritis. Results were correlated with presence or absence of urate and calcium pyrophosphate crystals, and Gram-stain result. During this time our collection and analysis methods remained unchanged. All samples were collected in Lithium Heparin containers. Chi-squared test with a p value &amp;lt; 0.05 was considered significant.</span></p><h4 style="font-size: 13px; margin: 0px 0.25em 0px 0px; text-transform: uppercase; float: left; font-family: arial, helvetica, clean, sans-serif;"><span style="font-size: 10pt;">RESULTS:</span></h4><p style="margin: 0px 0px 0.5em; font-size: 1.04em; font-family: arial, helvetica, clean, sans-serif;"><span style="font-size: 10pt;">602 synovial fluid samples were included. 162 cases of concomitant crystal arthritis were identified (27%). Of these, 16 (10%) had an initial negative Gram-stain. Of the 440 samples with no crystals detected, 18 (4%) had an initial negative Gram-stain microscopy result (p &amp;lt; 0.05).</span></p><h4 style="font-size: 13px; margin: 0px 0.25em 0px 0px; text-transform: uppercase; float: left; font-family: arial, helvetica, clean, sans-serif;"><span style="font-size: 10pt;">CONCLUSIONS:</span></h4><p style="margin: 0px 0px 0.5em; font-size: 1.04em; font-family: arial, helvetica, clean, sans-serif;"><span style="font-size: 10pt;">The incidence of concurrent septic and crystal arthritis may be higher than previously thought. Synovial fluid samples in concomitant septic and crystal arthritis are significantly less likely to have a positive Gram-stain at microscopy than in cases of an isolated septic arthritis. We would advise the clinician to maintain a high index of suspicion for septic arthritis in these patients.</span></p> |