bluuebunny/crossref_metadata_2025 huggingface dataset:
Does health system performance reporting stimulate change?
Authors: Leeb Kira
Published: September 2018

For numerous countries, including Canada, regular health system performance reporting has become increasingly routine if not mandated by legislation. In Canada, the health system performance reporting agenda includes multiple players at all levels from national organizations to provincial health (quality) councils and others. Canada, like many other countries, also participates in international health system performance reporting initiatives. Making sense of what all of these reporting initiatives are telling us about health system performance both within Canada and compared to other countries is becoming increasingly more challenging. For almost 20 years, the Canadian Institute for Health Information has worked with provinces, territories, and other key partners to develop comparable, standardized pan-Canadian performance indicators. Throughout this process, many lessons have been identified including the actionability one can reasonably expect from public reporting initiatives. This article outlines some of the key aspects of these lessons.
In vivo tissue response and antibacterial efficacy of minocycline delivery system based on polymethylmethacrylate bone cement
Authors: Silva Tiago , Silva Jose C , Colaco Bruno , Gama Adelina , Duarte-Araújo Margarida , Fernandes Maria H , Bettencourt Ana , Gomes Pedro
Published: September 2018

This study aims the in vivo biological characterization of an innovative minocycline delivery system, based on polymethylmethacrylate bone cement. Bone cements containing 1% or 2.5% (w/w) minocycline were formulated and evaluated through solid-state characterization. Biological evaluation was conducted in vivo, within a rat model, following the subcutaneous and bone tissue implantation, and tissue implantation associated with Staphylococcus aureus is challenging. The assessment of the tissue/biomaterial interaction was conducted by histologic, histomorphometric and microtomographic techniques. Minocycline addition to the composition of the polymethylmethacrylate bone cement did not modify significantly the cement properties. Drug release profile was marked by an initial burst release followed by a low-dosage sustained release. Following the subcutaneous tissue implantation, a reduced immune-inflammatory reaction was verified, with diminished cell recruitment and a thinner fibro-connective capsule formation. Minocycline-releasing cements were found to enhance the bone-to-implant contact and bone tissue formation, following the tibial implantation. Lastly, an effective antibacterial activity was mediated by the implanted cement following the tissue challenging with S. aureus. Kinetic minocycline release profile, attained with the developed polymethylmethacrylate system, modulated adequately the in vivo biological response, lessening the immune-inflammatory activation and enhancing bone tissue formation. Also, an effective in vivo antibacterial activity was established. These findings highlight the adequacy and putative application of the developed system for orthopedic applications.
Effects of calcium and phosphorus incorporation on the properties and bioactivity of TiO2 nanotubes
Authors: Soares Paulo , Dias-Netipanyj Marcela Ferreira , Elifio-Esposito Selene , Leszczak Victoria , Popat Ketul
Published: September 2018

In this study, we investigate the formation of calcium and phosphorus-doped TiO2 nanotubes, produced by potentiostatic anodization of Ti in viscous electrolyte-containing HF and Ca/P ions. Characterization of the produced oxide layer was conducted using scanning electron microscopy, glancing-angle X-ray diffraction, X-ray photoelectron spectroscopy, contact angle, and protein adsorption measurements. Adipose-derived stem cells were used to study material cytotoxicity, cell viability and proliferation, and cell morphology and growth. To evaluate the adipose-derived stem-cell differentiation, we investigated the expression of osteocalcin and osteopontin by cells as well as calcium mineralization. Results show that it was possible to produce a superhydrophilic titanium oxide nanotube layer with incorporation of Ca and P ions. The presence of Ca and P in the oxide layer not only improved the cell adhesion and proliferation but also stimulated the production of key marker proteins indicating differentiation of cells.
Engaging With Persons to Transcend Patient Safety
Authors: Carroll Karen
Published: September 2018

This article focuses on engaging with persons to transcend patient safety endeavors and improvement projects. Transcending patient safety involves a situational awareness and engaging to bring to the forefront the goals, dreams, and aspirations of those persons entrusted to nursing care.
The Ontogeny of Human Self-Consciousness
Authors: Rochat Philippe
Published: September 2018

Self-consciousness is an essential characteristic of what it means to be human and is arguably a unique adaptation of our species. Human self-consciousness is construed here as the propensity to perceive and be aware of oneself not only for oneself, but also through the evaluative eyes of other individuals. The origins and determinants of this characteristic remain wide-open questions. I propose a developmental account and suggest possible new directions in the investigation of genetic, brain, and cultural factors that play a role in the ontogeny of human self-conscious psychology.
Firm-specific Parameters and Earnings Management: A Study in the Indian Context
Authors: Das Ramesh Chandra , Mishra Chandra Sekhar , Rajib Prabina
Published: September 2018

This article examines the factors that influence the accrual-based earnings management (AM) and real earnings management (RM) in the Indian context. Different firm-specific parameters as determinants of AM and RM are examined using panel data for 268 listed Indian manufacturing firms for the period 2009–2013. To estimate the AM and RM, Modified Jones Model (Dechow, Sloan, & Sweeney, 1995) and Roychowdhury Model (2006, Journal of Accounting and Economics, 42(3), 335–370) are used, respectively. Findings based on these models indicate that the Indian firms indulge in both AM and RM. Firm-specific parameters namely growth opportunity, financial leverage, firm’s performance and business group affiliation positively affect both AM and RM, whereas firm’s size, institutional ownership and firm age affect negatively. However, accounting flexibility measured by the ratio of net operating assets and sales is only positively related to accrual-based earnings management. Overall, the study finds that firm’s growth opportunity, financial leverage, firm’s performance, institutional ownership, business group affiliation and firm’s age influence both AM and RM.
Approach on the improvement of the durability of an electrorheological valve
Authors: Bauerochs Tobias , Ulrich Stephan , Schneider Steffen , Bruns Rainer
Published: September 2018

This work presents an approach on the improvement of the durability of an electrorheological valve and an electrorheological fluid. The pressure difference which can be achieved with the electrorheological effect is determined at the electrorheological valve. In order to simulate realistic operating conditions and to obtain a time-dependent pressure difference, several experiments are carried out in which the electrorheological fluid is permanently loaded over a period of several days with a field strength of up to 5 kV/mm. The results show that a simulated operating time of 2000 h would be possible without any problems. The knowledge gained on the characteristics of the electrorheological valve and electrorheological fluid in continuous operation is important for the design of electrorheological applications in order to estimate and determine their service life.
Multi-objective storage location allocation optimization and simulation analysis of automated warehouse based on multi-population genetic algorithm
Authors: Jiao Yu-ling , Xing Xiao-cui , Zhang Peng , Xu Liang-cheng , Liu Xin-Ran
Published: September 2018

Aiming at the requirement of working efficiency and security of automated warehouse and taking the operation time of outbound–inbound, the equivalent center of gravity of overall shelf and the degree of relative accumulation of related products as the multi-objective functions, the mathematical model is constructed for multi-objective storage location allocation optimization. According to the simple weighted genetic algorithm, it is easily prone to the problem of immature convergence when solving multi-objective programming problems. So, the multi-population genetic algorithm is proposed to solve the mathematical model of storage location allocation optimization. Combining with the experiment data of toy car assembly and automated warehouse, the results of the automated warehouse storage location allocation are obtained. FlexSim dynamic simulation model is established based on the storage location allocation solution, the physical parameters of automated warehouse and the experimental requirements plan of vehicle model assembly. The operation effect of the model and the utilization rate of the equipment are analyzed. The result of multi-population genetic algorithm is more reasonable and effective. It is proved that the result of multi-population genetic algorithm is superior to the result of simple weighted genetic algorithm, which provides an effective method for storage location allocation optimization and outbound–inbound dynamic simulation.
S-plot2: Rapid Visual and Statistical Analysis of Genomic Sequences
Authors: Kalesinskas Laurynas , Cudone Evan , Fofanov Yuriy , Putonti Catherine
Published: September 2018

With the daily release of data from whole genome sequencing projects, tools to facilitate comparative studies are hard-pressed to keep pace. Graphical software solutions can readily recognize synteny by measuring similarities between sequences. Nevertheless, regions of dissimilarity can prove to be equally informative; these regions may harbor genes acquired via lateral gene transfer (LGT), signify gene loss or gain, or include coding regions under strong selection. Previously, we developed the software S-plot. This tool employed an alignment-free approach for comparing bacterial genomes and generated a heatmap representing the genomes’ similarities and dissimilarities in nucleotide usage. In prior studies, this tool proved valuable in identifying genome rearrangements as well as exogenous sequences acquired via LGT in several bacterial species. Herein, we present the next generation of this tool, S-plot2. Similar to its predecessor, S-plot2 creates an interactive, 2-dimensional heatmap capturing the similarities and dissimilarities in nucleotide usage between genomic sequences (partial or complete). This new version, however, includes additional metrics for analysis, new reporting options, and integrated BLAST query functionality for the user to interrogate regions of interest. Furthermore, S-plot2 can evaluate larger sequences, including whole eukaryotic chromosomes. To illustrate some of the applications of the tool, 2 case studies are presented. The first examines strain-specific variation across the Pseudomonas aeruginosa genome and strain-specific LGT events. In the second case study, corresponding human, chimpanzee, and rhesus macaque autosomes were studied and lineage specific contributions to divergence were estimated. S-plot2 provides a means to both visually and quantitatively compare nucleotide sequences, from microbial genomes to eukaryotic chromosomes. The case studies presented illustrate just 2 potential applications of the tool, highlighting its capability to identify and investigate the variation in molecular divergence rates across sequences. S-plot2 is freely available through https://bitbucket.org/lkalesinskas/splot and is supported on the Linux and MS Windows operating systems.
The mothers in me
Authors: Katila Saija
Published: September 2018

Abstraction of the narrative

The paper aims to evoke readers’ reflective and affective capacities and thereby facilitate understanding of the multisensorial, affective, and relational nature of knowing and becoming. It highlights the role of embodied knowing in becoming by following the journey of an individual faced with sudden trauma. It describes the affective energies crossing time and space in the continuously changing sociomaterial networks of relationships encountered in different organizational settings, be they in academia, health and social services, family, or otherwise. The paper is based on an auto-ethnographic narrative of becoming a mother that connects individual experiences with cultural understandings. The narrative is an outcome of a diffractive analysis of becoming; knowing emerges during the course of a writing process in which theoretical understandings, emotions, concepts, discourses, embodied experiences, and affects come together. The paper brings out the multiplicity of contradictory discourses involved in knowing and becoming. In so doing, it highlights the entangled coexistence of body and mind, reality and imagination, public and private, reason and emotion, as well as past, present, and future.
Effects of friction-based fixed bearings on seismic performance of high-speed railway simply supported girder bridges and experimental validation
Authors: Jiang Lizhong , Cao Shanshan , Wei Biao
Published: September 2018

This study investigated the seismic performance of simply supported girder bridges with a span length of 32 m. Those bridges were a common part in China’s high-speed railway system and used spherical bearings to connect girders and piers. First, a finite element model of the scaled bridge with a geometrical similarity ratio of 1:8 was established by OpenSees. Second, five seismic damage states of fixed bearings and piers were defined based on the deformation failure criterion. Finally, an incremental dynamic analysis and a pseudo-dynamic test were performed to evaluate the effects of friction-based fixed bearings on the seismic response and damage state of bearings and piers. Results show that the sliding of friction-based fixed bearings effectively restricts the force transmitting between piers and girders, and reduces the seismic damage of piers. Those bearings with a small friction coefficient lead to a large relative displacement between piers and girders, while those bearings with a large friction coefficient cause a large seismic force exceeding the yield load of piers. Therefore, an appropriate friction coefficient of friction-based fixed bearing should be determined to achieve an optimal seismic performance of bridge according to the specific conditions of bridge and ground motion inputs.
Angiotensin IV suppresses inflammation in the brains of rats with chronic cerebral hypoperfusion
Authors: Wang Qing-Guang , Xue Xiao , Yang Yang , Gong Peng-Yu , Jiang Teng , Zhang Ying-Dong
Published: September 2018

Introduction:

This study aimed to evaluate the influence of central angiotensin IV (Ang IV) infusion on chronic cerebral hypoperfusion (CCH)-related neuropathological changes including amyloid-β (Aβ), hyperphosphorylated tau (p-tau) and the inflammatory response.

Materials and methods:

Rats with CCH received central infusion of Ang IV, its receptor AT4R antagonist divalinal-Ang IV or artificial cerebrospinal fluid for six weeks. During this procedure, the systolic blood pressure (SBP) was monitored, and the levels of Aβ42, p-tau and pro-inflammatory cytokines in the brain were detected.

Results:

Rats with CCH exhibited higher levels of Aβ42, p-tau and pro-inflammatory cytokines in the brain when compared with controls. Infusion of Ang IV significantly reduced the expression of pro-inflammatory cytokines in the brains of rats with CCH. Meanwhile, the reduction of pro-inflammatory cytokines levels caused by Ang IV was reversed by divalinal-Ang IV. During the treatment, the SBP in rats was not significantly altered.

Conclusion:

This study demonstrates for the first time that Ang IV dose-dependently suppresses inflammation through AT4R in the brains of rats with CCH, which is independent from SBP. These findings suggest that Ang IV/AT4R may represent a potential therapeutic target for CCH-related neurological diseases.
Visual saliency–based image binarization approach for detection of surface microcracks by distributed optical fiber sensors
Authors: Song Qingsong , Abdoli Oskoui Elias , Taylor Todd , Ansari Farhad
Published: September 2018

Early detection of defects and anomalies is important for safety and efficient management of structural elements. Brillouin scattering–based optical fiber sensors provide distributed sensing capabilities by monitoring the strain and temperature over large distances in structural elements. Their use has been limited to oil and gas explorations, mainly due to the inherent low signal-to-noise ratio in such systems, preventing detection of microcracks in structural monitoring applications. This study introduces a method based on the visual saliency approach through which the digital images acquired by the distributed strain data are employed for the detection of surface microcracks. When using this method, strain data sequences along the entire length of a structural element are sampled with a Brillouin scattering–based optical fiber sensor and then divided into a set of equal-length subsequences. A similarity measure matrix is composed based on the distributed strain data and then converted into a grayscale image. The saliency maps of the acquired grayscale images are calculated and a center-hollowed square template is defined and exploited for convolution with the binarized saliency map as a filter operator. The pixels retained after the filtering correspond to the locations of microcracks. Verification of the method was accomplished by experiments on a 15-m-long steel beam with fabricated defects.
Resisting neoliberal policies in UK higher education: Exploring the impact of critical pedagogies on non-traditional students in a post-1992 university
Authors: Sanders-McDonagh Erin , Davis Carole
Published: September 2018

In this article, we focus on how neoliberal performance metrics impact on non-traditional students at a modern university in England. We argue that the introduction of ‘quality assurance’ measures, (such as the National Student Survey and the Teaching Excellence Framework) are driven by an ideology which purports to have student’s best interests at heart by raising teaching standards, focusing on graduate employability and wider participation, but in fact works to discourage critical pedagogic practices that would allow for more democratic and dialogic spaces of learning. This article presents findings from one multi-modal qualitative case study at a particular higher education institution in London, where many of the students originate from socially and economically deprived areas and frequently come from ethnic minority groups. We argue that the radical space of the classroom provides a unique opportunity for students to move into collective and empathetic modes of learning that yield both normative measures of ‘success’ as well as more transformative outcomes. We maintain that critical pedagogies work to disrupt the neoliberal narrative that champions individual success and the student-as-consumer model, and by doing so, helps to redress the persistent inequalities that non-traditional students face in UK higher education settings.
College-Bound: Transition Planning Strategies for Students With Type 1 Diabetes
Authors: Klein Kathleen , Wheeler Michelle , Yonkaitis Catherine F.
Published: September 2018

Transition planning is mandated for students who receive special education services; however, it is not required for students with chronic conditions. Students with chronic conditions nearing graduation would benefit from more intensive attention to their post–high school self-care needs and responsibilities. Students with type 1 diabetes must be able to understand the necessary self-care of one of the most complicated and intensive chronic conditions yet there are no evidence-based strategies for how to help students transition from the support provided at school to independence at graduation. The need for a student with type 1diabetes to independently manage their diabetes is even greater as the student leaves home for college. School nurses, who are also certified diabetes educators, created a support group for seniors with type 1 diabetes. The group focused on life after high school and provided the students with a detailed checklist to help improve knowledge and prepare students for the transition to college. Participants felt better prepared to move on to college armed with their checklist and other resources to help when away from home.
Future directions for mobile augmented reality research: Understanding relationships between augmented reality users, nonusers, content, devices, and industry
Authors: Liao Tony
Published: September 2018

As the field of mobile media studies continues to grow, researchers are focusing on new developments and trends in mobile technologies. One of these areas that has been garnering interest is mobile augmented reality (AR) technologies. While much of the earliest research in AR was primarily focused on answering computer science and engineering related questions, social science and humanities scholars have started taking note of AR as perhaps the next major development in mobile media. Given that much of this research has been distributed across interdisciplinary lines and from many different theoretical perspectives, this piece identifies some early lines of media, communication, and social science research into AR and identifies key themes and areas of focus: AR users/nonusers, AR devices, AR content, and AR industry. By organizing these lines of research, this manuscript serves as a call for specific future areas of research, suggests new approaches that researchers could take to explore interrelationships between these areas, and advocates for the necessity of research that examines different levels (micro/meso/macro) of analysis within AR. The goal of this piece is to advance a framework that informs and motivates mobile scholars to consider and integrate AR into their research areas, at a moment where it is in the process of moving from science fiction to material reality, from blueprint to prototype, and from laboratory to homes, cars, workplaces, and pockets.
Density and tailored breast cancer screening: practice and prediction – an overview
Authors: Wengert Georg J , Helbich Thomas H , Kapetas Panagiotis , Baltzer Pascal AT , Pinker Katja
Published: September 2018

Mammography, as the primary screening modality, has facilitated a substantial decrease in breast cancer-related mortality in the general population. However, the sensitivity of mammography for breast cancer detection is decreased in women with higher breast densities, which is an independent risk factor for breast cancer. With increasing public awareness of the implications of a high breast density, there is an increasing demand for supplemental screening in these patients. Yet, improvements in breast cancer detection with supplemental screening methods come at the expense of increased false-positives, recall rates, patient anxiety, and costs. Therefore, breast cancer screening practice must change from a general one-size-fits-all approach to a more personalized, risk-based one that is tailored to the individual woman’s risk, personal beliefs, and preferences, while accounting for cost, potential harm, and benefits.

This overview will provide an overview of the available breast density assessment modalities, the current breast density screening recommendations for women at average risk of breast cancer, and supplemental methods for breast cancer screening. In addition, we will provide a look at the possibilities for a risk-adapted breast cancer screening.
Effects of Exposure to New Car Interiors in Patients With Asthma and Allergic Rhinitis
Authors: Pepper Amber N. , Bulkhi Adeeb , Smith Catherine R. , Colli Matthias , Bergmann Karl-Christian , Zuberbier Torsten , Casale Thomas B.
Published: September 2018

Rationale

Vehicle interiors are an important microenvironment for atopic subjects. This study evaluated the subjective and objective physiologic and clinical effects of exposing subjects with asthma and allergic rhinitis to new 2017 Mercedes vehicles during 90-minute rides.

Methods

Ten adult asthmatics with allergic rhinitis were assessed before and 45 and 90 minutes into rides in a 2017 Mercedes-Benz S-Class sedan and GLE-Class SUV on 2 separate days. Assessments included spirometry, fractional exhaled nitric oxide, peak nasal inspiratory flow, asthma symptom scores, and physical examinations.

Results

Of the 10 subjects, 6 were women, mean age was 32 years, and 6 and 4 were using chronic asthma controllers or intranasal corticosteroids, respectively. None of the subjects had worsening of asthma or rhinitis symptoms during the rides. There were no statistically significant changes from baseline in forced expiratory volume in 1 second, forced expiratory volume in 1 second:forced vital capacity ratio, forced expiratory flow at 25%–75% of vital capacity, fractional exhaled nitric oxide, or peak nasal inspiratory flow at 45 or 90 minutes into the rides with either Mercedes vehicle (all P values > .1 using generalized linear mixed model).

Conclusion

The interior environment of the tested Mercedes vehicles did not cause changes in subjective or objective measures of asthma and allergic rhinitis. We suggest that this model system can be used to test other vehicles for putatively adverse effects on patients with allergic respiratory disorders.
A Seat at the Top? A Historical Appraisal of Brazil’s Case for the UN Security Council
Authors: Garcia Eugenio V. , Coelho Natalia B. R.
Published: September 2018

Emerging powers have increasingly been vocal about reforming the structures of global governance. Brazil has asserted itself both as a player to be reckoned with in multilateral organizations and as a candidate for permanent membership at the United Nations Security Council. This article aims at investigating the circumstances surrounding Brazil’s efforts at three historical moments: the failed attempt to gain a permanent seat on the Council of the League of Nations, the short-lived campaign to become the “sixth permanent member” of the Security Council in 1945, and the candidacy in the 1990s and after. Although some studies focus on each candidature separately, there is not a comprehensive comparison to put them into perspective. By comparing how foreign policy was conducted by different administrations, the article sheds light on the future behavior that could be expected from Brazil on this issue, regardless of the government in charge.
Self-Reported Skin Disorders Among Health Care Workers
Authors: Alhaji Mohammed Mohammed , Lai Alice , Naing Lin , Tuah Nik Ani
Published: September 2018

This study aimed to estimate the point prevalence and 1-year period prevalence of skin disorder symptoms (SDS) among health care workers (HCWs) and to explore the possible risk factors. A random sample of 400 HCWs from 13 government health centers in Brunei Darussalam self-administered an adapted Nordic Occupational Skin Questionnaire (NOSQ-2002/SHORT). The point and 1-year prevalence of SDS were 12% and 19%, respectively. Having a history of SDS before the current job, exposure to SDS-exacerbating materials at the workplace, and having clinical roles were correlated for both prevalence estimates. Frequent handwashing and moderate use of latex gloves were associated with higher risk of SDS at 1-year. Female HCWs were more likely to report SDS. In multivariate analyses, only contact with SDS-exacerbating materials at the workplace, prejob SDS, and moderate glove usage were significant predictors of SDS.
A Return to Functional Analysis, the Search for Mechanisms of Change, and the Nomothetic-Idiographic Issue in Psychosocial Interventions
Authors: Davison Gerald C.
Published: September 2018

In this invited commentary, I provide an historical and conceptual context for “The Future of Intervention Science: Process-Based Therapy” by Stefan Hofmann and Steven Hayes (this issue, p. 37). Special attention is paid to the importance of change mechanisms in psychological intervention, the use of functional analysis instead of categorical schemes such as the Diagnostic and Statistical Manual of Mental Disorders and treatment manuals in randomized clinical trials, and the challenge of applying nomothetic principles to individual cases. Historical context is provided for prior examination of these core issues in numerous articles and books extending back for over 60 years.
Does Patient-specific Instrumentation Yield Better Component Position than Standard Instrumentation in Total Ankle Arthroplasty?
Authors: Escudero Mario , Wing Kevin , Waly Feras , Bemenderfer Thomas , Davis W. Hodges , Anderson Robert , Penner Murray
Published: September 2018

Category:

Ankle Arthritis

Introduction/Purpose:

The unique anatomy and biomechanics of the ankle joint have made total ankle arthroplasty (TAA) challenging over the past few decades. Final implant position and successful soft tissue balancing are key components to the longevity of total ankle implants. Preoperative computer navigation, templating, and patient-specific instrumentation (PSI) have shown promising results in total ankle replacement with accurate and reproducible radiographic outcomes. Recent data has also suggested that even experienced surgeons benefit from the improved time efficiency of PSI. The purpose of this study is to determine if radiographic outcomes differ between patients undergoing TAA with PSI and those who undergo TAA with standard instrumentation (SI).

Methods:

The first 67 consecutive patients who underwent primary Infinity total ankle arthroplasty (TAA) at 2 North American sites between 2013 and 2015 were reviewed in a prospective observational study. All TAA’s were performed by one of four fellowship-trained foot and ankle surgeons. Demographic, radiographic, and functional outcome data was collected preoperatively, at 6-12 months postoperatively, and annually thereafter. The radiographic variables measured were the medial distal tibial angle (MDTA), talar tilt angle (TTA), lateral talar station (LTS), sagittal distal tibial articular angle (sDTAA), and the gamma angle. Acceptable intervals for each parameter were selected and TAAs were then categorized as being “correctly aligned” or “not correctly aligned” for all the parameters described. The rate of “correctly aligned” TAA’s was compared between cases with PSI and those with SI. Fisher’s exact test was used to analyze difference by groups. A significance of 5% was used.

Results:

Of a total of 67 TAAs included, 51 were in the PSI group and 16 in the SI group. No significant statistically differences were found between PSI and NPSI regarding MDTA (p=0.174), LTS (p=0.922), sDTAA (p=0.986), gamma angle (p=0.252) and TTA (p=0.145). We did not find a significant statistical difference in the rate of “correctly aligned TAR” when we compared both groups (p=0.35).

Conclusion:

This study suggests that both PSI and SI provide accurate and reproducible TAA radiographic alignment when performed by experienced surgeons. In view of previously published data demonstrating high levels of reproducibility for PSI in TAA, these data also suggest that PSI may offer a means for less experienced surgeons to achieve radiographic results similar to those achieved by experienced surgeons. It also suggests that experienced surgeons may not need to use PSI to achieve satisfactory implant alignment, though improved time efficiency with PSI, as demonstrated in other studies, may still be of benefit for experienced surgeons.
Predicting Failure in Total Ankle Arthroplasty. A COFAS study
Authors: Escudero Mario , Le Vu (Brian) , Veljkovic Andrea , Wing Kevin , Younger Alastair , Penner Murray
Published: September 2018

Category:

Ankle Arthritis

Introduction/Purpose:

Total ankle arthroplasty (TAA) and ankle arthrodesis (AA) are standard treatment modalities for end-stage ankle osteoarthritis. The total ankle arthroplasty (TAA) anatomical alignment is critical for the longevity of total ankle components. Coronal and sagittal malalignment results in altered joint mechanics and reactive forces that result in implant failure. Also, to our knowledge, tibial component sizing in the sagittal plane has been addressed in knee arthroplasty literature, but not in ankle arthroplasty literature. Based on these parameters, we developed a novel radiographic predictive score for failure in TAA (RPSFT).

Methods:

A retrospective review performed on the COFAS database, selecting for all total ankle replacements done at a single institution between September 2004 and June 2015. Those with complete series of anteroposterior and lateral standing ankle radiographs, both preoperative and postoperative and a minimum of 1 year of follow-up, were included. We performed a multivariate logistic regression, using the medial distal tibial component angle, lateral talar station, talar tilt angle, and the absence of posterior under= or overhang of the tibial component in the first post-operative radiographs. These parameters were used to develop a RPSFT. Binomial regression was used to determine each variable’s weight in the RPSFT and assigned a corresponding score value. A univariate logistic regression was estimated, using the RPSFT as the independent variable and mechanical failure as the dependent variable. Then a Receiver-Operating Characteristic curve was constructed and the probability of failure for each possible score was estimated.

Results:

Of a total of 296 TAAs, 146 were included, and 8 TAAs required revision (5%). TAA revision was defined as a reoperation to remove one or both metal components, or amputation. According to our predictive score, if all the parameters are within established normal ranges (17 points) the TAA failure probability (TFP) is 2% [0-0.1] p<0.01. If none of them are obtained (0 points) the TFP rise to 42% p<0.01 (see attached table). Time to TAA failure averaged 4.4 years and ranged from 1.4 to 9.6 years.

Conclusion:

Our model suggests that a coronal and sagittal alignment and absence of tibial implant under/overhang are of vital importance to prevent TAA failure. To our knowledge, this is the first study that presents a predictive score for failure in TAA using postoperative ALSAR. Further data analyses are ongoing and may expand our predictive model to include other radiographic parameters.
Should 15° of Valgus Coronal-Plane Deformity Be the Upper Limit for a Total Ankle Replacement?
Authors: Halai Mansur , Mann Matthew , Khan Ryan , Pinsker Ellie , Daniels Timothy
Published: September 2018

Category:

Ankle Arthritis

Introduction/Purpose:

Preoperative talar valgus deformity increases the technical difficulty of total ankle replacement (TAR) and is associated with an increased failure rate. Deformity of ≥15° has been reported to be a contraindication to arthroplasty. The goal of the present study was to determine whether the clinical outcomes of TAR for treatment of end-stage ankle arthritis were comparable for patients with preoperative talar valgus deformity of ≥15° as compared to those with <15°.

Methods:

Fifty ankles with preoperative coronal-plane tibiotalar valgus deformity of ≥15° (“valgus” group) and 50 ankles with valgus deformity of <15° (“control” group) underwent TAR. The cohorts were similar with respect to demographics and components used. All TARs were performed by a single surgeon. The mean duration of clinical follow-up was 5.5 years (minimum two years). Preoperative and postoperative radiographic measurements of coronal-plane deformity, Ankle Osteoarthritis Scale (AOS) scores and Short Form (SF)-36 scores were prospectively recorded. All ancillary (intraoperative) and secondary procedures, complications and measurements were collected.

Results:

The AOS pain and disability subscale scores decreased significantly in both groups. The improvement in AOS and SF-36 scores did not differ significantly between the groups at the time of the final follow-up. The valgus group underwent more ancillary procedures during the index surgery (80% vs 26%). Tibio-talar deformity improved significantly toward a normal weight-bearing axis in the valgus group. Secondary postoperative procedures were more common in the valgus group (36%) than the controls (20%). Overall, re-operation was not associated with poorer patient outcome scores. Metal component revision surgery occurred in seven patients (three valgus and four controls). These revisions included two deep infections (2%), one in each group, which were converted to hindfoot fusions. Therefore, 94% of the valgus group retained their original components at final follow-up.

Conclusion:

Satisfactory midterm results were achieved in patients with valgus mal-alignment of ≥15°. The valgus cohort required more procedures during and after their TAR, as well as receiving more novel techniques to balance their TAR. Whilst longer term studies are needed, valgus coronal-plane alignment of ≥15° should not be considered an absolute contraindication to TAR if the associated deformities are addressed.
Outcomes of Acute Hematogenous Periprosthetic Joint Infection in Total Ankle Arthroplasty Treated with Irrigation, Debridement, and Polyethylene Exchange
Authors: Lachman James , Ramos Jania A. , Nunley James , DeOrio James , Adams Samuel
Published: September 2018

Category:

Ankle

Introduction/Purpose:

Acute hematogenous periprosthetic joint infection(PJI) is defined in the literature as infection diagnosed and treated within two to four weeks from the onset of symptoms. In total hip and knee arthroplasty, irrigation, debridement(I&D) and polyethylene exchange with component retention is the treatment of choice. There is minimal literature evaluating this treatment method for PJI in total ankle arthroplasty (TAA), however, with four patients being the largest sample size. The purpose of this study was to evaluate both the clinical and patient reported outcomes and survivorship of treating PJI in TAA with I&D and polyethylene exchange in patients with acute hematogenous PJIs.

Methods:

A single center, retrospective chart review of prospectively collected data in patients with TAA PJI who subsequently underwent I&D and polyethylene exchange with retention of metal components was conducted. The primary outcome was failure rate of I&D and polyethylene exchange where failure was defined as subsequent removal of all components and two-stage revision or arthrodesis. Patient reported outcomes collected before primary arthroplasty, after primary arthroplasty and after polyethylene exchange were also analyzed.

Results:

We identified 11 patients with acute hematogenous PJI who underwent I&D/ polyethylene exchange with retention of metal components. The average time from onset of symptoms to I&D/ polyethylene exchange was 11.55 days +/-5.57. The mean follow-up after this surgery was 2.8 years +/-1.45. The long-term failure rate was 50%. The most common bacteria isolated in patients who failed was Methicillin Resistant Staphylococcus Aureus (MRSA). The most common bacteria isolated in patients who retained their implants was Methicillin Sensitive Staphylococcus Aureus(MSSA). Visual Analog Scale (VAS), Short Musculoskeletal Function Assessment (SMFA), Short Form-36 (SF36), and American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scale showed significant improvement when compared to preoperative scores in patients who retained their implants both after primary and after I&D and polyethylene exchange.

Conclusion:

I&D and polyethylene exchange with retention of metal components has comparable long-term survivorship to those reported in the Knee and Hip Arthroplasty literature. Patient reported outcomes after I&D and polyethylene exchange were comparable to those collected after primary arthroplasty in patients who ultimately retained their implants. Two variables which were independent predictors of failure of this surgery include duration of symptoms prior to I&D as well as organism isolated on culture. With a failure rate of 50%, the authors recommend thorough evaluation on a case by case basis prior to indicating a patient for single stage I&D with polyethylene exchange.
Posterior Malleolar Ankle Fractures
Authors: Mason Lyndon , Widnall James , Redfern James , Swanton Eric , Molloy Andrew
Published: September 2018

Category:

Ankle

Introduction/Purpose:

There is an increasing acceptance that the clinical outcomes following posterior malleolar fractures are less than satisfactory. In creating a treatment guiding classification and algorithm, we report our results in a system change in management of posterior malleolar fractures in our unit.

Methods:

All fractures were classified according to Mason and Molloy classification (Foot Ankle Int. 2017 Nov;38(11):1229-1235) based on CT scans obtained pre-operatively. This dictated the treatment algorithm. Type 1 fractures underwent syndesmotic fixation. Type 2A fractures underwent ORIF through a posterolateral incision, and type 2B and 3 fractures underwent ORIF through a posteromedial incision. The patient remained NWB for 6 weeks postoperative. Data was collected prospectively from December 2014 to July 2017.

Results:

Patient-related outcome measures were obtained in 50 patients with at least 1 year follow up (mean 18 months). The overall OMAS score for all posterior malleolar fractures in this cohort was 74.1 (range 35-100). According to Mason and Molloy classification, the mean OMAS for type 1 was 75.9 (Range 30-100), type 2A 75.0 (range 35-100), type 2B 74.0 (range 55-100) and type 3 70.5 (Range 35-100). Using one way ANOVA test, there was no significant difference (p=.886) between groups or within groups. There was a trend, however, that the lower the Mason and Molloy classification had higher OMAS outcomes. The overall 1-year EQ-5D index for this cohort was 0.88 (SD 0.22). The average visual analogue score for this patient group was 77.5 (SD 26.2).

Conclusion:

We have been able to demonstrate an improvement in functional scores for all posterior malleolar fractures with the treatment algorithm applied using the Mason and Molloy classification. This is compared to our previous study where traditional posterior malleolar management was undertaken. Our OMAS scores have now improved to what would be expected from unimalleolar fractures, illustrating the importance of understanding the injury mechanism and patterns of injury. Mason and Molloy type 3 fractures have marginally poorer outcomes, which correlates with a more significant injury.
Mechanical and Anatomical Axis in Total Ankle Arthroplasty
Authors: Najefi Ali-Asgar , Goldberg Andrew
Published: September 2018

Category:

Ankle Arthritis

Introduction/Purpose:

Inadequate correction of alignment in the coronal, sagittal or axial planes will inevitably lead to failure of the Total Ankle Arthroplasty (TAA). The mechanical axis of the lower limb (MAL), the mechanical axis of the tibia (MAT) and the anatomical axis of the tibia (AAT) are three recognized coronal plane measurements using plain radiography. The relationship between anatomical and mechanical axes depends on the presence of femoral or tibial deformities from trauma or inherited conditions, or previous corrective or replacement surgery. Ankle arthroplasty relies heavily on preoperative radiographs or CT scans and the purpose of this study was to assess whether MAL, MAT and AAT are the same in a cohort of patients upon which placement of TAA is considered.

Methods:

We analysed 75 patients operated on between 2015 and 2016 at a specialist tertiary centre for elective orthopaedic surgery. All patients had a pre-operative long leg radiograph. They were split into 2 groups. The first group had known deformity proximal to the ankle (such as previous tibial or femoral fracture, severe arthritis, or previous reconstructive surgery) and the second group had no clinically detectable deformity. The MAL, MAT and AAT were assessed and the difference between these values was calculated.

Results:

There were 54 patients in the normal group, and 21 patients in the deformity group. Overall, 25 patients(33%) had a difference between all three axes of less than 1 degree. In 33 patients(44%), there was a difference in one of the axes of ≥2 degrees. There was no significant difference between MAT and AAT in patients in the normal group(p=0.6). 95% of patients had a difference of <1 degree. There was a significant difference between the MAT and AAT in patients in the deformity group(p<0.01). In the normal group, 39 patients(73%) had a difference of <2 degrees between the AAT and MAL. In the deformity group, only 10 patients (48%) had a difference of <2 degrees.In fact, 24% of patients had a difference ≥3 degrees.

Conclusion:

Malalignment in the coronal plane in TAA may be an issue that we have not properly addressed. Up to 66% of patients without known deformity may have a TAA that is placed at least 1 degree incorrectly relative to the MAL. We recommend the use of full-length lower limb radiographs when planning a TAA in order to plan the placement of implants. The decision to perform extramedullary referencing, intramedullary referencing, or patient specific Instrumentation must be part of the pre-operative planning process.