Cell Count and Differential of Aspirated Fluid in the Diagnosis of Infection at the Site of Total Knee Arthroplasty

Ghanem, Elie; Parvızı, Javad; Burnett, R. Stephen J.; Sharkey, Peter F.; Keshavarzi, Nahid; Aggarwal, Ajay; Barrack, Robert L.

doi:10.2106/jbjs.g.00470

Cited by 279 publications

(152 citation statements)

References 21 publications

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“…Several studies have demonstrated that the levels of WBC and differential in the synovial fluid become elevated during PJI along with elevated blood levels. Therefore, it is believed that synovial fluid cell count and differentials follow the fluctuation patterns of the serum [11,25,28].…”

Section: Discussionmentioning

confidence: 99%

Premature Therapeutic Antimicrobial Treatments Can Compromise the Diagnosis of Late Periprosthetic Joint Infection

Shahi

Deirmengian

Higuera

et al. 2015

Clinical Orthopaedics &Amp; Related Research

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Background In the absence of positive cultures and draining sinuses, the diagnosis of periprosthetic joint infection (PJI) relies on laboratory values. It is unknown if administration of antibiotics within 2 weeks before diagnostic evaluations can affect these tests in patients with PJI. Questions/purposes The purpose of this study was to investigate the correlation of antibiotic administration with (1) fluctuations in the synovial fluid and serology laboratory values; and (2) sensitivity of the diagnostic tests in patients with late PJI (per Musculoskeletal Infection Society [MSIS] criteria). Methods Synovial white blood cell (WBC) count, polymorphonuclear neutrophil (PMN) percentage, and serum erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) as well as culture results were investigated in 161 patients undergoing total knee arthroplasty with late PJI diagnosed with the MSIS criteria. Depending on whether presampling antibiotics were used, patients were divided in two groups (53 [33%] patients were on antibiotics). The median laboratory values and the false-negative rates were compared between the two groups.

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Section: Discussionmentioning

confidence: 99%

Premature Therapeutic Antimicrobial Treatments Can Compromise the Diagnosis of Late Periprosthetic Joint Infection

Shahi

Deirmengian

Higuera

et al. 2015

Clinical Orthopaedics &Amp; Related Research

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“…We found no advantage to the use of synovial-fluid CRP over serum CRP in the diagnosis of PJI; moreover, in 15% of patients, the synovial-fluid test could not be performed, perhaps making it of even lower utility. Thus, collected synovial fluid is best used to obtain a cell count with a differential and cultures [3,10,16,21,22,27,28,31,32]; diverting the sample for the measurement of CRP does not appear warranted at this time.…”

Section: Discussionmentioning

confidence: 99%

Is Synovial C-reactive Protein a Useful Marker for Periprosthetic Joint Infection?

Tetreault

Wetters

Moric

et al. 2014

Clin Orthop Relat Res

102

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Background Serum C-reactive protein (CRP) is a general marker of inflammation, and recent studies suggest that measurement of CRP in synovial fluid may be a more accurate method for diagnosing periprosthetic joint infection (PJI). Questions/purposes We aimed to (1) determine if there is a correlation between serum and synovial CRP values, (2) establish cutoff values for diagnosing infection based on serum and synovial CRP, and (3) compare the utility of measuring CRP in synovial fluid versus serum for the diagnosis of PJI using standard assay equipment available at most hospitals. Methods Between February 2011 and March 2012, we invited all 150 patients scheduled for revision TKA (84) or THA (66) to participate in this prospective study, of whom 100% agreed. Data ultimately were missing for 31 patients, leaving 60 patients undergoing revision TKA and 59 undergoing revision THA (71% and 89% of the original group, respectively) for whom CRP level was measured in serum and synovial fluid samples. Patients were deemed to have a PJI (32) or no infection (87) using Musculoskeletal Infection Society criteria. Serum and synovial CRP levels were assayed using the same immunospectrophotometer and the correlation coefficient was calculated. Receiver operating characteristic curve analyses were performed to compare utility in diagnosing PJI, which included area under the curve, diagnostic threshold, and test sensitivity, specificity, predictive values, and accuracy. In 22 of 150 patients (14.7%), synovial CRP could not be measured because the sample was too viscous or hemolyzed. Results In the analyzed 119 samples, there was a strong correlation (r = 0.76; p \ 0.001) between synovial and serum CRP. The area under the curve was 0.90 both for the synovial fluid (95% CI, 0.82-0.97) and serum (95% CI, 0.84-0.96) CRP assays. The diagnostic thresholds were 6.6 mg/L for synovial fluid and 11.2 mg/L for serum. Sensitivities, specificities, positive predictive value, negative predictive value, and accuracies were similar for synovial fluid and serum assays. Conclusions Although recent studies have suggested a superiority of synovial fluid CRP over serum CRP for the diagnosis of PJI, we found that measurement of CRP in synovial fluid rather than serum using readily available

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“…The sensitivity and specificity of the AD-1 assay were determined and 95% CIs were calculated [8]. The predetermined cutoffs for the other tests were greater than 1700 cells/mm 3 for cell count, greater than 30 mm/hour for erythrocyte sedimentation rate, and greater than 10 mg/L for C-reactive protein [1,5,6,11]. The sensitivity and specificity and the confidence intervals of the AD-1 assay were compared with the cultures, cell count, erythrocyte sedimentation rate, and C-reactive protein.…”

Section: Methodsmentioning

confidence: 99%

“…The symptoms of PJI often are nonspecific, therefore making the diagnosis of PJI can be challenging [4]. Individually, currently available laboratory tests used to detect infection have been shown to be inadequate in diagnosing a PJI [5,6,10]. Even the definition of what constitutes a PJI is a topic of controversy [9].…”

Section: Introductionmentioning

confidence: 99%

The Alpha Defensin-1 Biomarker Assay can be Used to Evaluate the Potentially Infected Total Joint Arthroplasty

Bingham

Clarke

Spangehl

et al. 2014

Clin Orthop Relat Res

179

115

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Background Diagnosing a periprosthetic joint infection (PJI) requires a complex approach using various laboratory and clinical criteria. A novel approach to diagnosing these infections uses synovial fluid biomarkers. Alpha defensin-1 (AD-1) is one such synovial-fluid biomarker. However little is known about the performance of the AD-1 assay in the diagnosis of PJI. Questions/purposes We sought to (1) determine the sensitivity and specificity of the AD-1 assay in a population of patients being evaluated for PJI, using the Musculoskeletal Infection Society (MSIS) criteria as the reference standard, and (2) compare the AD-1 assay with other currently available clinical tests, specifically cell count, culture, erythrocyte sedimentation rate, and C-reactive protein.Patients and Methods A retrospective review was performed of all patients undergoing workup for a PJI at our institution from January to June 2013. Sixty-one AD-1 assays were done in 57 patients. The group included 51 patients with 55 painful joints and six patients who underwent aspiration before second-stage reimplantation. Patients were considered to have a PJI if they met the MSIS criteria. We calculated the sensitivity and specificity of the AD-1 synovial fluid assay, and compared it with the sensitivity and specificity of the synovial fluid cell count, culture, erythrocyte sedimentation rate, and C-reactive protein. There were 19 diagnosed infections in the 61 aspirations, with 21 positive and 40 negative AD-1 assays. There were two false positive and no false negatives AD-1 assays. Results The sensitivity and specificity for the AD-1 assay were 100% (95% CI, 79%-100%) and 95% (95% CI, 83%-99%), respectively. The sensitivity and specificity of the other tests ranged from 68% to 95% and 66% to 88%, respectively. The AD-1 assay results outperformed the other tests but did not reach statistical significance except for the sensitivity of the erythrocyte sedimentation rate. Conclusion The sensitivity and specificity of the synovial fluid AD-1 assay exceeded the sensitivity and specificity of the other currently available clinical tests evaluated here but did not reach significance. The AD-1 assay offers another test with high sensitivity and specificity for diagnosing a PJI especially in the case where the diagnosis of PJI is uncertain, but larger studies will be needed to determine significance and cost effectiveness. Level of Evidence Level III, diagnostic study. See the Instructions for Authors for a complete description of levels of evidence.

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Cell Count and Differential of Aspirated Fluid in the Diagnosis of Infection at the Site of Total Knee Arthroplasty

Cited by 279 publications

References 21 publications

Premature Therapeutic Antimicrobial Treatments Can Compromise the Diagnosis of Late Periprosthetic Joint Infection

Premature Therapeutic Antimicrobial Treatments Can Compromise the Diagnosis of Late Periprosthetic Joint Infection

Is Synovial C-reactive Protein a Useful Marker for Periprosthetic Joint Infection?

The Alpha Defensin-1 Biomarker Assay can be Used to Evaluate the Potentially Infected Total Joint Arthroplasty

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