Sensitivity and Specificity of Serum and Synovial Fluid Markers in Diagnosis of Infection in Head-Neck Taper Corrosion of Metal-On-Polyethylene Total Hip Arthroplasty

Abstract Background Total nucleated cell (TNC) count and differential are used to classify joint effusions as inflammatory or noninflammatory. Further diagnostic evaluation and management is contingent on this classification. TNC count can be measured by automated analyzers or by manual assessment using a hemocytometer. Studies have raised concerns regarding the accuracy of TNC counts measured by automated instruments, particularly in the setting of joint arthroplasty. The objective of this study was to determine whether metallosis, a complication of total hip arthroplasty in which metal debris accumulates in periprosthetic tissues and synovial fluid, is associated with inaccurate TNC counts in synovial fluid. Methods We compared the accuracy of cell counts measured by the Sysmex XN-1000 and Beckman Coulter Iris iQ200 with the gold standard of manual assessment using a hemocytometer in synovial fluid from patients with suspected metallosis and in fluid obtained from controls from patients with native joints and a history of arthroplasty for other indications. Results TNC counts produced by automated analyzers were associated with increased levels of discordance (relative to manual counts) in patients with metallosis. Metallosis was not associated with increased levels of discordance for RBC counts or WBC differentials. The Sysmex XN flagged all but 1 metallosis sample for manual verification of the results. Conclusions Automated methods are generally reliable for analysis of synovial fluid. TNC counts can be inaccurate in the context of metallosis following total hip arthroplasty. Laboratories should correlate automated cell counts with a microscopic assessment of the specimen, as recommended by instrument manufacturers.

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Combination of CRP with NLR is a sensitive tool for screening fixation-related infection in patients undergoing conversion total hip arthroplasty after failed internal fixation for femoral neck fracture

The Bone & Joint Journal ◽

10.1302/0301-620x.103b.bjj-2021-0105.r1 ◽

2021 ◽

pp. 1-7

Author(s):

Hong Xu ◽

Jin-Wei Xie ◽

Li Liu ◽

Duan Wang ◽

Ze-Yu Huang ◽

...

Keyword(s):

Total Hip Arthroplasty ◽

Femoral Neck ◽

Internal Fixation ◽

Femoral Neck Fracture ◽

Sensitivity And Specificity ◽

Hip Arthroplasty ◽

Lymphocyte Ratio ◽

Total Hip ◽

Sensitive Tool ◽

Neck Fracture

Aims Monocyte-lymphocyte ratio (MLR) or neutrophil-lymphocyte ratio (NLR) are useful for diagnosing periprosthetic joint infection (PJI), but their diagnostic values are unclear for screening fixation-related infection (FRI) in patients for whom conversion total hip arthroplasty (THA) is planned after failed internal fixation for femoral neck fracture. Methods We retrospectively included 340 patients who underwent conversion THA after internal fixation for femoral neck fracture from January 2008 to September 2020. Those patients constituted two groups: noninfected patients and patients diagnosed with FRI according to the 2013 International Consensus Meeting Criteria. Receiver operating characteristic (ROC) curves were used to determine maximum sensitivity and specificity of these two preoperative ratios. The diagnostic performance of the two ratios combined with preoperative CRP or ESR was also evaluated. Results The numbers of patients with and without FRI were 19 (5.6%) and 321 (94.4%), respectively. Areas under the ROC curve for diagnosing FRI were 0.763 for MLR, 0.686 for NLR, 0.905 for CRP, and 0.769 for ESR. Based on the Youden index, the optimal predictive cutoffs were 0.25 for MLR and 2.38 for NLR. Sensitivity and specificity were 78.9% and 71.0% for MLR, and 78.9% and 56.4% for NLR, respectively. The combination of CRP with MLR showed a sensitivity of 84.2% and specificity of 94.6%, while the corresponding values for the combination of CRP with NLR were 89.5% and 91.5%, respectively. Conclusion The presence of preoperative FRI among patients undergoing conversion THA after internal fixation for femoral neck fracture should be determined. The combination of preoperative CRP with NLR is sensitive tool for screening FRI in those patients.

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Femoral head material loss at the head-neck junction in total hip arthroplasty: the effect of head size, stem material and stem offset

Hip International ◽

10.1177/1120700018814473 ◽

2018 ◽

Vol 29 (6) ◽

pp. 647-651 ◽

Cited By ~ 1

Author(s):

Giuseppe Valente ◽

Brent Lanting ◽

Steven MacDonald ◽

Matthew G Teeter ◽

Douglas Van Citters ◽

...

Keyword(s):

Femoral Head ◽

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Head Size ◽

Material Loss ◽

Total Hip ◽

Femoral Heads ◽

Measuring Machine ◽

Head Neck ◽

Neck Junction

Introduction:Material loss at the head-neck junction in total hip arthroplasty may cause adverse clinical symptoms and implant failure. The purpose of this study was to quantitatively examine the effects of head size, stem material and stem offset on material loss of the head-neck taper interface of a single trunnion design in retrieval implants of metal on polyethylene bearing surfaces.Methods:A retrieval study was performed to identify all 28-mm and 32-mm femoral heads from a single implant/taper design implanted for >2 years. This included n = 56 of the 28-mm heads and n = 23 of the 32-mm heads. The 28-mm femoral heads were matched to 32-mm femoral heads based on time in vivo and head length. A coordinate measuring machine was used to determine maximum linear corrosion depth (MLD). Differences in MLD for head diameter, stem material, and stem offset were determined.Results:There were no differences between groups for age, gender, BMI, or implantation time. There was no difference in MLD between 28 mm and 32 mm matched paired head diameters ( p = 0.59). There was also no difference in MLD between titanium or cobalt-chromium stems ( p = 0.79), and regular or high-offset stems ( p = 0.95).Conclusion:There is no statistical difference in femoral head MLD at the head-neck junction in THA between 28-mm and 32-mm matched paired femoral heads, similar or mixed alloy coupled femoral head stem constructs, and regular or high offset stems.

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Ultrasound for diagnosis of infection in revision total hip arthroplasty

The Journal of Arthroplasty ◽

10.1054/arth.2001.24378 ◽

2001 ◽

Vol 16 (8) ◽

pp. 1010-1017 ◽

Cited By ~ 26

Author(s):

T. Eisler ◽

O. Svensson ◽

C.-F. Engström ◽

F.P. Reinholt ◽

Christina Lundberg ◽

...

Keyword(s):

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Revision Total Hip Arthroplasty ◽

Total Hip ◽

Diagnosis Of Infection

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Metal on Metal Bearing in Total Hip Arthroplasty and Its Impact on Synovial Cell Count

Journal of Clinical Medicine ◽

10.3390/jcm9103349 ◽

2020 ◽

Vol 9 (10) ◽

pp. 3349

Author(s):

Henrik C. Bäcker ◽

Chia H. Wu ◽

David Krüger ◽

Clemens Gwinner ◽

Carsten Perka ◽

...

Keyword(s):

Synovial Fluid ◽

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Periprosthetic Joint Infection ◽

Joint Infection ◽

Control Group ◽

Total Hip ◽

Metal On Metal ◽

Matching Criteria ◽

The Impact

Introduction: The effect of different bearings on synovial white blood cell (WBC) count and polymorphonuclear percentage (PMN%) in aspirations remains unclear. Therefore, this study investigates the impact of aseptic Metal-on-Metal (MoM) bearing on synovial fluid. Methods: We searched our arthroplasty registry for aseptic painful THAs with MoM bearings between 2011 and 2018. Then, a case-matched control group was selected with septic and aseptic Total Hip Arthroplasty (THA) with ceramic on a polyethylene (PE) bearing. The matching criteria consisted of gender, age +/−10 years, and time of aspiration (+/−2years). Periprosthetic Joint Infection (PJI) was defined according to the Infectious Diseases Society of America (IDSA), and Musculoskeletal Infection Society (MSIS) using bacterial cultures, sonication and histology. Results: In total, 19 patients who underwent hip aspiration with MoM bearing were identified. Five patients had to be excluded due to insufficient synovial fluid obtained (n = 2) or bacterial growth after sonication that was initially negative with the standard microbiological cultures (n = 3). As such, 14 were included. These patients were matched with 14 aseptic and 14 septic THAs with ceramic on a PE bearing, which constituted the control group. The mean serum chrome level was 20.0 ± 15.5 nmol/L and cobalt level 18.4 ± 22.1 nmol/L. The synovial WBC and PMN% varied significantly between MoM bearing group and the aseptic THA ceramic PE group (both p < 0.001), as well as the septic THA group (WBC p = 0.016, PMN% p < 0.001). Furthermore, the septic THA group had significantly higher CRP values than the aseptic MoM group (p = 0.016). Conclusion: MoM bearing shows significantly higher synovial WBC and PMN% when compared to aseptic THA with ceramic on PE bearing above the MSIS cut-off. This is an important consideration when diagnosing periprosthetic joint infection using the MSIS guidelines.

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