Neurocysticercosis is a neurologic parasitic disease caused by the encysted larva of the tapeworm Taenia solium and is the most important parasitic disease of the human central nervous system. It is ...the most common cause of acquired epilepsy in endemic settings and constitutes a public health challenge for most of the developing world. Nowadays, however, as a result of globalization, neurocysticercosis is being seen more frequently in developed countries as well. Neurocysticercosis is acquired through fecal-oral contamination, and the disease course is complex, with two intermediate hosts (ie, pigs and humans) and a definitive host (humans). Traditionally, it has been classified into active and nonactive forms according to disease location. Radiologists must be aware of its imaging appearance, which is quite variable, as is the differential diagnosis. Imaging findings depend on several factors, including the stage of the life cycle of T solium at presentation; the number and location (ie, subarachnoid, cisternal, or intraventricular) of parasites; and associated complications such as vascular involvement (ie, arteritis with or without infarction), inflammatory response (ie, edema, gliosis, or arachnoiditis), and, in ventricular forms, degree of obstruction. Thus, the diagnostic approach, management, and prognosis for neurocysticercosis differ widely depending on the type of infection.
Nanoscale light sources using metal cavities have been proposed to enable high integration density, efficient operation at low energy per bit and ultra-fast modulation, which would make them ...attractive for future low-power optical interconnects. For this application, such devices are required to be efficient, waveguide-coupled and integrated on a silicon substrate. We demonstrate a metal-cavity light-emitting diode coupled to a waveguide on silicon. The cavity consists of a metal-coated III-V semiconductor nanopillar which funnels a large fraction of spontaneous emission into the fundamental mode of an InP waveguide bonded to a silicon wafer showing full compatibility with membrane-on-Si photonic integration platforms. The device was characterized through a grating coupler and shows on-chip external quantum efficiency in the 10
-10
range at tens of microamp current injection levels, which greatly exceeds the performance of any waveguide-coupled nanoscale light source integrated on silicon in this current range. Furthermore, direct modulation experiments reveal sub-nanosecond electro-optical response with the potential for multi gigabit per second modulation speeds.
Patient-reported outcome measures are increasingly recognized as an important tool in quantifying the clinical success of arthroplasty surgery. The aim of this study is to measure post-operative ...joint awareness and satisfaction in patients with and without a quantitatively balanced knee following primary total knee arthroplasty (TKA).
In this multi-center study, a total of 318 eligible patients were assigned to one of the 2 patient groups: sensor-guided TKA or surgeon-guided TKA. In the sensor-guided group, quantitative balancing was performed according to intercompartmental tibiofemoral load measurements measured by an instrumented tibial trial component. In contrast, for the surgeon-guided group, the knees were balanced according to the surgeons’ standard manual techniques while blinding the surgeon to the sensor measurements. Patients were blinded to their allocation and filled out the validated Forgotten Joint Score and 2011 Knee Society Satisfaction questionnaires at 6 weeks and 6 months. For the purposes of this study, the subjects were pooled and stratified by their state of soft tissue balance, based on the mediolateral load differential through the range of motion.
In the surgeon-guided group, approximately 50% of the cases yielded a quantitatively balanced knee. Significantly more balanced knees were observed in the sensor-guided group (84.0%). More importantly, for both outcome measures, the balanced group of patients reported significantly better outcomes scores.
This demonstrates that using sensor feedback during knee arthroplasty surgery results in a more reproducible procedure, resulting in a higher percentage of balanced patients who in turn demonstrate superior clinical outcomes compared to unbalanced patients.
Although HbA1c is commonly used for assessing glycemic control before surgery, there is no consensus regarding its role and the appropriate threshold in predicting adverse outcomes. This study was ...designed to evaluate the potential link between HbA1c and subsequent periprosthetic joint infection (PJI), with the intention of determining the optimal threshold for HbA1c.
This is a multicenter retrospective study, which identified 1645 diabetic patients who underwent primary total joint arthroplasty (1004 knees and 641 hips) between 2001 and 2015. All patients had an HbA1c measured within 3 months of surgery. The primary outcome of interest was a PJI at 1 year based on the Musculoskeletal Infection Society criteria. Secondary outcomes included orthopedic (wound and mechanical complications) and nonorthopedic complications (sepsis, thromboembolism, genitourinary, and cardiovascular complications). A regression analysis was performed to determine the independent influence of HbA1c for predicting PJI.
Overall 22 cases of PJI occurred at 1 year (1.3%). HbA1c at a threshold of 7.7 was distinct for predicting PJI (area under the curve, 0.65; 95% confidence interval, 0.51-0.78). Using this threshold, PJI rates increased from 0.8% (11 of 1441) to 5.4% (11 of 204). In the stepwise logistic regression analysis, PJI remained the only variable associated with higher HbA1c (odds ratio, 1.5; confidence interval, 1.2-2.0; P = .0001). There was no association between high HbA1c levels and other complications assessed.
High HbA1c levels are associated with an increased risk for PJI. A threshold of 7.7% seems to be more indicative of infection than the commonly used 7% and should perhaps be the goal in preoperative patient optimization.
Abstract Background The current gold standard to diagnose periprosthetic joint infection (PJI)—the Musculoskeletal Infection Society (MSIS) criteria, requires a battery of tests, the results of which ...may not be available at the time of decision-making. Thus, surgeons often rely on intraoperative frozen section histology. However, the accuracy of frozen sections has not been determined when matched for the MSIS criteria. We aimed to (1) assess the value of intraoperative histology in the diagnosis of PJI and (2) evaluate discrepancy rate between frozen and permanent section analysis. Methods A retrospective review of patients who underwent revision total hip or total knee arthroplasty for either PJI or mechanical failure in 2013 was conducted. Two hundred procedures where tissue samples for frozen sections had been collected were identified and included into the study. Results of frozen sections were compared to the modified MSIS criteria. Discrepancy rate between frozen and permanent sections was also calculated. Results Frozen sections had sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 73.7% (95% confidence interval CI, 59.7%-87.7%), 98.8% (95% CI, 97.1%-100.0%), 94.1% (95% CI, 90.6%-97.6%), 93.3.4% (95% CI, 84.4%-100.0%), 94.0% (95% CI, 90.7%-97.3%), respectively. There were 10 discrepancies between the results of frozen and permanent sections (N = 421 samples), thereby yielding 97.6% concordance. Conclusion When matched to the MSIS criteria, intraoperative frozen section histology yields a high specificity, positive predictive value, negative predictive value, accuracy, and moderate sensitivity. The discrepancy rate between frozen and permanent sections is low and both demonstrate good approximation of MSIS criteria.
Abstract Background The purpose of this study was to test the accuracy of a single synovial fluid biomarker, α-defensin, in diagnosing periprosthetic joint infection in revision total hip and ...revision total knee arthroplasty. Methods A total of 102 patients comprising 116 revision total hip arthroplasty and revision total knee arthroplasty procedures performed between May 2013 and March 2014 were prospectively evaluated. Cases were categorized as infected or notinfected using Musculoskeletal Infection Society criteria. Synovial fluid was obtained and tested for α-defensin using a commercially available kit (Synovasure CD Diagnostics, Baltimore, Maryland). Results For first-stage and single-stage revisions, the α-defensin test had a sensitivity of 100% (95% confidence interval CI, 86%-100%) and a specificity of 98% (95% CI, 90%-100%) with a positive predictive value of 96% (95% CI, 80%-99%) and negative predictive value of 100% (95% CI, 93%-100%). Conclusion A positive α-defensin test result was significantly more sensitive and specific for predicting infection than current diagnostic testing and should be considered when managing periprosthetic joint infection. Level of Evidence: Level III, Study of Diagnostic Test.
The diagnosis of periprosthetic joint infection (PJI) is difficult and requires a battery of tests and clinical findings. The purpose of this review is to summarize all current evidence for common ...and new serum biomarkers utilized in the diagnosis of PJI.
We searched two literature databases, using terms that encompass all hip and knee arthroplasty procedures, as well as PJI and statistical terms reflecting diagnostic parameters. The findings are summarized as a narrative review.
Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were the two most commonly published serum biomarkers. Most evidence did not identify other serum biomarkers that are clearly superior to ESR and CRP. Other serum biomarkers have not demonstrated superior sensitivity and have failed to replace CRP and ESR as first-line screening tests. D-dimer appears to be a promising biomarker, but more research is necessary. Factors that influence serum biomarkers include temporal trends, stage of revision, and implant-related factors (metallosis).
Our review helped to identify factors that can influence serum biomarkers' level changes; the recognition of such factors can help improve their diagnostic utility. As such, we cannot rely on ESR and CRP alone for the diagnosis of PJI prior to second-stage reimplantation, or in metal-on-metal or corrosion cases. The future of serum biomarkers will likely shift towards using genomics and proteomics to identify proteins transcribed via messenger RNA in response to infection and sepsis.
2018;7:85-93.
Background
Frozen section histology is widely used to aid in the diagnosis of periprosthetic joint infection at the second stage of revision arthroplasty, although there are limited data regarding ...its utility. Moreover, there is no definitive method to assess control of infection at the time of reimplantation. Because failure of a two-stage revision can have serious consequences, it is important to identify the cases that might fail and defer reimplantation if necessary. Thus, a reliable test providing information about the control of infection and risk of subsequent failure is necessary.
Questions/purposes
(1) At second-stage reimplantation surgery, what is the diagnostic accuracy of frozen sections as compared with the Musculoskeletal Infection Society (MSIS) as the gold standard? (2) What are the diagnostic accuracy parameters for the MSIS criteria and frozen sections in predicting failure of reimplantation? (3) Do positive MSIS criteria or frozen section at the time of reimplantation increase the risk of subsequent failure?
Methods
A total of 97 patients undergoing the second stage of revision total hip arthroplasty or total knee arthroplasty in 2013 for a diagnosis of periprosthetic joint infection (PJI) were considered eligible for the study. Of these, 11 had incomplete MSIS criteria and seven lacked 1-year followup, leaving 79 patients (38 knees and 41 hips) available for analysis. At the time of reimplantation, frozen section results were compared with modified MSIS criteria as the gold standard in detecting infection. Subsequently, success or failure of reimplantation was defined by (1) control of infection, as characterized by a healed wound without fistula, drainage, or pain; (2) no subsequent surgical intervention for infection after reimplantation surgery; and (3) no occurrence of PJI-related mortality; and diagnostic parameters in predicting treatment failure were calculated for both the modified MSIS criteria and frozen sections.
Results
At the time of second-stage reimplantation surgery, frozen section is useful in ruling in infection, where the specificity is 94% (95% confidence interval CI, 89%–99%); however, there is less utility in ruling out infection, because sensitivity is only 50% (CI, 13%–88%). Both the MSIS criteria and frozen sections have high specificity for ruling in failure of reimplantation (MSIS criteria specificity: 96% CI, 91%–100%; frozen section: 95% CI, 88%–100%), but screening capabilities are limited (MSIS sensitivity: 26% CI, 9%–44%; frozen section: 22% CI, 9%–29%). Positive MSIS criteria at the time of reimplantation were a risk factor for subsequent failure (hazard ratio HR, 5.22 1.64–16.62, p = 0.005), whereas positive frozen section was not (HR, 1.16 0.15–8.86, p = 0.883).
Conclusions
On the basis of our results, both frozen section and MSIS are recommended at the time of the second stage of revision arthroplasty. Both frozen section and modified MSIS criteria had limited screening capabilities to identify failure, although both demonstrated high specificity. MSIS criteria should be evaluated at the second stage of revision arthroplasty because performing reimplantation in a joint that is positive for infection significantly increases the risk for subsequent failure.
Level of Evidence
Level III, diagnostic study.
The III–V semiconductor InGaAs is a key material for photonics because it provides optical emission and absorption in the 1.55 μm telecommunication wavelength window. However, InGaAs suffers from ...pronounced nonradiative effects associated with its surface states, which affect the performance of nanophotonic devices for optical interconnects, namely nanolasers and nanodetectors. This work reports the strong suppression of surface recombination of undoped InGaAs/InP nanostructured semiconductor pillars using a combination of ammonium sulfide, (NH4)2S, chemical treatment and silicon oxide, SiO x , coating. An 80-fold enhancement in the photoluminescence (PL) intensity of submicrometer pillars at a wavelength of 1550 nm is observed as compared with the unpassivated nanopillars. The PL decay time of ∼0.3 μm wide square nanopillars is dramatically increased from ∼100 ps to ∼25 ns after sulfur treatment and SiO x coating. The extremely long lifetimes reported here, to our knowledge the highest reported to date for undoped InGaAs nanostructures, are associated with a record-low surface recombination velocity of ∼260 cm/s. We also conclusively show that the SiO x capping layer plays an active role in the passivation. These results are crucial for the future development of high-performance nanoscale optoelectronic devices for applications in energy-efficient data optical links, single-photon sensing, and photovoltaics.
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