Unicompartmental Knee Arthroplasty Is Associated with a Lower Rate of Periprosthetic Joint Infection Compared to Total Knee Arthroplasty

Background: Several studies have reported lower perioperative complications with unicompartmental knee arthroplasty (UKA) than with total knee arthroplasty (TKA). However, there is a paucity of data analyzing the incidence of periprosthetic joint infection (PJI) in similar patients undergoing UKA and TKA. As such, we sought to analyze the incidence of UKA and TKA PJI in a large matched population. Material and Methods: The Mariner data set of the PearlDiver database was queried for all patients undergoing UKA or TKA during 2010-2017. Included patients were required to have at least 2 years of database inclusion after surgery. Patients were then matched at a 1:3 ratio (UKA:TKA) on age, gender, Elixhauser Comorbidity Index, tobacco use, and obesity. Rates of PJI requiring operative intervention within 90 days and 1 year were calculated. Results: In total, 5636 patients having undergone UKA were matched to 16,890 patients having undergone TKA. Fifteen (0.27%) after UKA and 79 (0.47%) after TKA had a PJI surgically managed within 90 days (risk ratio = 0.57, 95% confidence interval = 0.33-0.99, P = .04). Thirty (0.53%) after UKA and 136 (0.81%) after TKA had a PJI surgically managed within 1 year (risk ratio = 0.66, 95% confidence interval = 0.45-0.98, P = .04). Conclusions: In a large group of rigorously matched patients, UKA was associated with a significantly lower rate of surgically managed PJI than TKA at 90 days and 1 year; however, the rate of PJI in both groups remained low at \u3c 1% at 90 days and 1 year

Exposure of Soil Microbial Communities to Chromium and Arsenic Alters Their Diversity and Structure

Extensive use of chromium (Cr) and arsenic (As) based preservatives from the leather tanning industry in Pakistan has had a deleterious effect on the soils surrounding production facilities. Bacteria have been shown to be an active component in the geochemical cycling of both Cr and As, but it is unknown how these compounds affect microbial community composition or the prevalence and form of metal resistance. Therefore, we sought to understand the effects that long-term exposure to As and Cr had on the diversity and structure of soil microbial communities. Soils from three spatially isolated tanning facilities in the Punjab province of Pakistan were analyzed. The structure, diversity and abundance of microbial 16S rRNA genes were highly influenced by the concentration and presence of hexavalent chromium (Cr (VI)) and arsenic. When compared to control soils, contaminated soils were dominated by Proteobacteria while Actinobacteria and Acidobacteria (which are generally abundant in pristine soils) were minor components of the bacterial community. Shifts in community composition were significant and revealed that Cr (VI)-containing soils were more similar to each other than to As contaminated soils lacking Cr (VI). Diversity of the arsenic resistance genes, arsB and ACR3 were also determined. Results showed that ACR3 becomes less diverse as arsenic concentrations increase with a single OTU dominating at the highest concentration. Chronic exposure to either Cr or As not only alters the composition of the soil bacterial community in general, but affects the arsenic resistant individuals in different ways

Evaluation of Multi-Level Barriers and Facilitators in a Large Diabetic Retinopathy Screening Program in Federally Qualified Health Centers: A Qualitative Study

BACKGROUND: Recommended annual diabetic retinopathy (DR) screening for people with diabetes has low rates in the USA, especially in underserved populations. Telemedicine DR screening (TDRS) in primary care clinics could expand access and increase adherence. Despite this potential, studies have observed high variability in TDRS rates among clinics and over time, highlighting the need for implementation supports. Previous studies of determinants of TDRS focus on patients\u27 perspectives, with few studies targeting upstream multi-level barriers and facilitators. Addressing this gap, this qualitative study aimed to identify and evaluate multi-level perceived determinants of TDRS in Federally Qualified Health Centers (FQHCs), to inform the development of targeted implementation strategies. METHODS: We developed a theory-based semi-structured interview tool based on the Consolidated Framework for Implementation Research (CFIR). We conducted 22 key informant interviews with professionals involved in TDRS (administrators, clinicians, staff). The interviews were audio-recorded and transcribed verbatim. Reported barriers and facilitators were organized into emergent themes and classified according to CFIR constructs. Constructs influencing TDRS implementation were rated for each study site and compared across sites by the investigators. RESULTS: Professionals identified 21 main barriers and facilitators under twelve constructs of the five CFIR domains. Several identified themes were novel, whereas others corroborated previous findings in the literature (e.g., lack of time and human resources, presence of a champion). Of the 21 identified themes, 13 were classified under the CFIR’s Inner Setting domain, specifically under the constructs Compatibility and Available Resources. Themes under the Outer Setting domain (constructs External Incentives and Cost) were primarily perceived by administrators, whereas themes in other domains were perceived across all professional categories. Two Inner Setting (Leadership Engagement, Goals and Feedback) and two Process (Champion, Engaging) constructs were found to strongly distinguish sites with high versus low TDRS performance. CONCLUSIONS: This study classified barriers and facilitators to TDRS as perceived by administrators, clinicians, and staff in FQHCs, then identified CFIR constructs that distinguished high- and low-performance clinics. Implementation strategies such as academic detailing and collection and communication of program data and successes to leadership; engaging of stakeholders through involvement in implementation planning; and appointment of intervention champions may therefore improve TDRS implementation and sustainment in resource-constrained settings

Close companions around young stars

Multiplicity is a fundamental property that is set early during stellar lifetimes, and it is a stringent probe of the physics of star formation. The distribution of close companions around young stars is still poorly constrained by observations. We present an analysis of stellar multiplicity derived from APOGEE-2 spectra obtained in targeted observations of nearby star-forming regions. This is the largest homogeneously observed sample of high-resolution spectra of young stars. We developed an autonomous method to identify double lined spectroscopic binaries (SB2s). Out of 5007 sources spanning the mass range of $\sim$0.05--1.5 \msun, we find 399 binaries, including both RV variables and SB2s. The mass ratio distribution of SB2s is consistent with a uniform for $q0.95$. The period distribution is consistent with what has been observed in close binaries ($<10$ AU) in the evolved populations. Three systems are found to have $q\sim$0.1, with a companion located within the brown dwarf desert. There are not any strong trends in the multiplicity fraction (MF) as a function of cluster age from 1 to 100 Myr. There is a weak dependence on stellar density, with companions being most numerous at $\Sigma_*\sim30$ stars/pc$^{-2}$, and decreasing in more diffuse regions. Finally, disk-bearing sources are deficient in SB2s (but not RV variables) by a factor of $\sim$2; this deficit is recovered by the systems without disks. This may indicate a quick dispersal of disk material in short-period equal mass systems that is less effective in binaries with lower $q$.Comment: 25 pages, 20 figures. Accepted to A

Occult Pneumothoraces in Children With Blunt Torso Trauma

Objectives Plain chest x‐ray (CXR) is often the initial screening test to identify pneumothoraces in trauma patients. Computed tomography (CT) scans can identify pneumothoraces not seen on CXR (“occult pneumothoraces”), but the clinical importance of these radiographically occult pneumothoraces in children is not well understood. The objectives of this study were to determine the proportion of occult pneumothoraces in injured children and the rate of treatment with tube thoracostomy among these children. Methods This was a planned substudy from a large prospective multicenter observational cohort study of children younger than 18 years old evaluated in emergency departments (EDs) in the Pediatric Emergency Care Applied Research Network (PECARN) for blunt torso trauma from May 2007 to January 2010. Children with CXRs as part of their trauma evaluations were included for analysis. The faculty radiologist interpretations of the CXRs and any subsequent imaging studies, including CT scans, were reviewed for the absence or presence of pneumothoraces. An “occult pneumothorax” was defined as a pneumothorax that was not identified on CXR, but was subsequently demonstrated on cervical, chest, or abdominal CT scan. Rates of pneumothoraces and placement of tube thoracostomies and rate differences with 95% confidence intervals (CIs) were calculated. Results Of 12,044 enrolled in the parent study, 8,020 (67%) children (median age = 11.3 years, interquartile range [IQR] = 5.3 to 15.2 years) underwent CXRs in the ED, and these children make up the study population. Among these children, 4,276 had abdominal CT scans performed within 24 hours. A total of 372 of 8,020 children (4.6%; 95% CI = 4.2% to 5.1%) had pneumothoraces identified by CXR and/or CT. The CXRs visualized pneumothoraces in 148 patients (1.8%; 95% CI = 1.6% to 2.2%), including one false‐positive pneumothorax, which was identified on CXR, but was not demonstrated on CT. Occult pneumothoraces were present in 224 of 372 (60.2%; 95% CI = 55.0% to 65.2%) children with pneumothoraces. Tube thoracostomies were performed in 85 of 148 (57.4%; 95% CI = 49.0% to 65.5%) children with pneumothoraces on CXR and in 35 of 224 (15.6%; 95% CI = 11.1% to 21.1%) children with occult pneumothoraces (rate difference = –41.8%; 95% CI = –50.8 to –32.3%). Conclusions In pediatric patients with blunt torso trauma, pneumothoraces are uncommon, and most are not identified on the ED CXR. Nearly half of pneumothoraces, and most occult pneumothoraces, are managed without tube thoracostomy. Observation, including in children requiring endotracheal intubation, should be strongly considered during the initial management of children with occult pneumothoraces. Resumen Objetivos La radiografía de tórax simple (RXT) es a menudo la prueba de despistaje inicial para identificar los neumotórax en los pacientes con traumatismo. La tomografía computarizada (TC) puede identificar neumotórax no vistos en la RXT (“neumotórax ocultos”), aunque la importancia clínica de estos neumotórax radiográficamente ocultos en los niños no está muy estudiada. Los objetivos de este estudio fueron determinar la proporción de neumotórax ocultos en los niños accidentados y el porcentaje de tratamiento con tubo de toracostomía en estos niños. Metodología Subestudio diseñado a partir de un gran estudio observacional de cohorte prospectivo multicéntrico de niños menores de 18 años atendidos en los servicios de urgencias (SU) de la Pediatric Emergency Care Applied Research Network (PECARN) que habían sido evaluados por traumatismo torácico cerrado de mayo de 2007 a enero de 2010. Se incluyeron en el análisis los niños en los que la RXT fue parte de la evaluación inicial del traumatismo. Las interpretaciones del radiólogo de las RXT y de cualquier estudio de imagen posterior, incluyendo a TC, se revisaron para la ausencia o presencia de neumotórax. Se definió “neumotórax oculto” como un neumotórax que no fue identificado en la RXT pero que fue posteriormente visualizado en la TC abdominal, torócica o cervical. Se calcularon los porcentajes de neumotórax e inserción de tubo de toracostomía y las diferencias de sus porcentajes con los intervalos de confianza (IC) al 95%. Resultados De los 12.044 incluidos en el estudio principal, se llevo a cabo una RXT en el SU en 8.020 (67%) niños (mediana de edad 11,3 años, rango intercuartílico 5,3 a 15,2), que constituyeron la población de estudio. De estos niños, 4.276 tuvieron una TC realizada en las primeras 24 horas. En 372 de los 8.020 niños (4,6%; IC 95% = 4,2% a 5,1%) se identificó un neumotórax en la RXT y/o la TC. La RXT mostró neumotórax en 148 pacientes (1,8%; IC 95% = 1,6% a 2,2%), incluyendo un falso positivo de neumotórax, que fue identificado en la RXT pero que no fue demostrado en la TC. Los neumotórax ocultos estuvieron presentes en 224 de los 372 niños con neumotórax (60,2%; IC 95% = 55,0% a 65,2%). Se insertaron tubos de toracostomía en 85 de los 148 niños con neumotórax en la RXT (57,4%; IC 95% = 49,0% a 65,5%), y en 35 de los 224 niños con neumotórax oculto (15,6%; IC 95% = 11,1% a 21,1%; diferencia de porcentajes ‐41,8%; IC 95% = ‐50,8 a ‐32,3%). Conclusiones En los pacientes pediátricos con traumatismo torácico cerrado, los neumotórax son poco frecuentes, y la mayoría no son identificados en la RXT en el SU. Casi la mitad de los neumotórax, y la mayoría de los neumotórax ocultos son manejados sin tubo de toracostomía. La observación, incluyendo en los niños que requieren intubación endotraqueal, debería ser especialmente considerada durante el manejo inicial de los niños con neumotórax ocultos.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106913/1/acem12344.pd

Comparison of Clinician Suspicion Versus a Clinical Prediction Rule in Identifying Children at Risk for Intra‐abdominal Injuries After Blunt Torso Trauma

ObjectivesEmergency department (ED) identification and radiographic evaluation of children with intra‐abdominal injuries who need acute intervention can be challenging. To date, it is unclear if a clinical prediction rule is superior to unstructured clinician judgment in identifying these children. The objective of this study was to compare the test characteristics of clinician suspicion with a derived clinical prediction rule to identify children at risk of intra‐abdominal injuries undergoing acute intervention following blunt torso trauma.MethodsThis was a planned subanalysis of a prospective, multicenter observational study of children (50% prior to knowledge of abdominal computed tomography (CT) scanning (if performed). Intra‐abdominal injuries undergoing acute intervention were defined by a therapeutic laparotomy, angiographic embolization, blood transfusion for abdominal hemorrhage, or intravenous fluid administration for 2 or more days in those with pancreatic or gastrointestinal injuries. Patients were considered to be positive for clinician suspicion if suspicion was documented as ≥1%. Suspicion ≥ 1% was compared to the presence of any variable in the prediction rule for identifying children with intra‐abdominal injuries undergoing acute intervention.ResultsClinicians recorded their suspicion in 11,919 (99%) of 12,044 patients enrolled in the parent study. Intra‐abdominal injuries undergoing acute intervention were diagnosed in 203 (2%) patients. Abdominal CT scans were obtained in the ED in 2,302 of the 2,667 (86%, 95% confidence interval [CI] = 85% to 88%) enrolled patients with clinician suspicion ≥1% and in 3,016 of the 9,252 (33%, 95% CI = 32% to 34%) patients with clinician suspicion  50% previamente a conocer la tomografía computarizada (TC) abdominal (si fue realizada). La LIA con necesidad de intervención urgente se definió como laparotomía terapéutica, embolización angiográfica, transfusión de sangre por hemorragia intrabdominal o administración de fluidos intravenosos durante 2 o más días en aquéllos con lesiones pancreáticas o gastrointestinales. Los pacientes se consideraron positivos para la sospecha clínica si la sospecha se documentó como ≥1%. La sospecha > 1% se comparó con la presencia de cualquier variable en la regla de predicción para la identificación de niños con LIA con necesidad de una intervención urgente.ResultadosLos clínicos documentaron su sospecha en 11.919 (99%) de los 12.044 pacientes incluidos en el estudio original. La LIA con necesidad de intervención urgente se diagnosticó en 203 (2%) pacientes. Las TC abdominales se obtuvieron en el SU en 2.302 de los 2.667 pacientes (86%, IC95% = 85% a 88%) incluidos con sospecha clínica ≥1%; y en 3.016 de los 9.252 pacientes (33%, IC95% = 32% a 34%) con sospecha clínica < 1%. La sensibilidad de la regla de predicción para LIA con necesidad de intervención aguda fue mayor que la sospecha clínica ≥1% (197 de 203, 97,0%, IC95% = 93,7% a 98,9%, frente a 168 de 203, 82,8%, IC95% = 76,9% a 87,7%, respectivamente; diferencia de 14,2%, IC95% = 8,6% a 20,0%). La especificidad de la regla de predicción, sin embargo, fue menor que la sospecha clínica (4,979 de los 11.716, 42,5%, IC95% = 41,6% a 43,4%, frente a 9,217 de los 11.716, 78,7%, IC95% = 77,9% a 79,4%, respectivamente; diferencia de –36,2%, IC95% = –37,3% a –35,0%). Treinta y cinco de los pacientes con sospecha clínica < 1% (0,4%, IC95% = 0,3% a 0,5%) tuvieron LIA con necesidad de intervención urgente.ConclusionesLa regla de predicción clínica derivada tuvo una sensibilidad mayor de forma significativa, pero menor especificidad que la sospecha clínica para la identificación de niños con necesidad de una intervención urgente. La mayor especificidad de la sospecha clínica, sin embargo, no se tradujo en la práctica clínica, ya que los clínicos obtuvieron más frecuentemente TC abdominales en los pacientes que consideraron de muy bajo riesgo. Si se validase, esta regla de predicción puede ayudar en la toma de decisiones clínicas sobre el uso de TC abdominal en los niños con traumatismo torácico cerrado.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113736/1/acem12739.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/113736/2/acem12739_am.pd

Triggerable tough hydrogels for gastric resident dosage forms

Systems capable of residing for prolonged periods of time in the gastric cavity have transformed our ability to diagnose and treat patients. Gastric resident systems for drug delivery, ideally need to be: ingestible, be able to change shape or swell to ensure prolonged gastric residence, have the mechanical integrity to withstand the forces associated with gastrointestinal motility, be triggerable to address any side effects, and be drug loadable and release drug over a prolonged period of time. Materials that have been primarily utilized for these applications have been largely restricted to thermoplastics and thermosets. Here we describe a novel set of materials, triggerable tough hydrogels, meeting all these requirement, supported by evaluation in a large animal model and ultimately demonstrate the potential of triggerable tough hydrogels to serve as prolonged gastric resident drug depots. Triggerable tough hydrogels may be applied in myriad of applications, including bariatric interventions, drug delivery, and tissue engineering.Bill & Melinda Gates Foundation (Grant OPP1096734)Bill & Melinda Gates Foundation (Grant OPP1139927)National Institutes of Health (U.S.) (Grant EB000244

Explorations, Vol. 4, No. 1

Articles include: Cover: Old Yarmouth Light, 1960, Cape Forchu, Nova Scotia. By and from the collection of Edgar McKay. The Borderlands Concept: a new look at U.S.-Canada relations, by Victor Konrad and Lauren McKensey Fundy Tidal Power Project, by Gregory White Canadian Poet: Ken Norris Native American Life and Art: a celebration, November, 1986, by Lee-Ann Konrad The Montreal Canadiens: a cultural institution, by James J. Herlan U.S. and Canadian Executives: uses of formal and informal plans in top executive decision-making, by Kent Carter Our Cover Artist: bits and pieces of one man\u27s Nova Scotia, by Edgar McKay The Canadian-American Center and the Canadian Collection of the Fogler Library, by Alice Stewart Capitalist Development in the New England-Atlantic Provinces Region, by Robert H. Babcock Atlantic Canadian Members of Parliament as Representatives, by Howard Cody The Rower and the Pyramid: a tribute to Joe Walsh, by Edward D. Ives The Canadian-American Center: exercise in excellence, by Rand Erb Canadian and Maine Potatoes: a bushel of questions, by George K. Griner, Alan S. Kezis, and James D. Leiby After 20: the Future of the Canadian-American Center, by Victor Konra