bluuebunny/crossref_metadata_2025 huggingface dataset:
Adaptive aeroelastic control of nonlinear airfoil with multiple flaps under unsteady flow
Authors: Zhang K , Marzocca P , Behal A
Published: August 2015

In this paper, a fully adaptive control design is considered for a four-degree-of-freedom aeroelastic system that has structural nonlinearities and operates in an unsteady aerodynamic incompressible flowfield. By using the flap hinge torque of a trailing-edge flap surface in combination with a leading-edge active flap, a closed-loop controller that adapts for uncertainties in the system parameters is designed. An implicit observer is implemented in the control design to compensate for lack of measurements of the lag states that model the unsteady flow. The innovative Lyapunov-based control design procedure results in a partial-state feedback adaptive controller that is globally asymptotically stable. Numerical simulation results show the effectiveness of the control strategy; comparative simulations are run to illustrate the benefit of using twin flaps as opposed to the conventional single flap control design.
Living With and Within the Rules of Domestic Violence Shelters
Authors: Glenn Catherine , Goodman Lisa
Published: August 2015

As emergency domestic violence (DV) shelters have proliferated, there has been an increase in rules that shelter residents must follow. This qualitative descriptive study explores intimate partner violence (IPV) survivors’ experiences living with DV shelter rules. Five thematic clusters emerged from interviews with 11 survivors: (1) shelter environment/staff approach, (2) making sense of the rules, (3) staff enforcement of the rules, (4) short-term impact of the rules, and (5) coping. Results suggest that residents benefit from more flexible boundaries between staff and residents, less restrictive rules, and collaborative, transparent rule enforcement. Recommendations are made for shelter practice and future research.
How Do Golf Tourists Manage Golfing Constraints? A Choice Modeling Approach
Authors: Lyu Seong Ok , Lee Youngjin
Published: August 2015

Although there has been a remarkable increase in the supply of domestic golf courses in South Korea, the demand for golf trips is believed to have reached a plateau. In this competitive environment, golf course managers need to examine diverse constraining factors that discourage their customers from visiting the facilities, and learn how those constraints are managed by golf tourists through a variety of strategies. Using a choice modeling, this study provides useful opportunities to better understand golf tourists’ choices made by intricate comparisons between negotiation strategies that help relieve the impact of golfing constraints. The results indicate that levels of perceived importance vary on several constraint attributes when golf tourists make decisions for golf trips. This study also identifies heterogeneous preferences for negotiation strategies between two golf tourist groups segmented based on their golfing experiences.
Entertaining International Tourists: An Empirical Study of an Iconic Site in China
Authors: Pearce Philip L. , Wu Mao-Ying
Published: August 2015

Entertainment is a feature of some tourism settings and acts as a key pull factor for visiting certain destinations. Research-based studies about entertainment and the tourist experience are, however, rather limited. This study pursued this research opportunity and explored international tourists’ experiences in an iconic performance-based entertainment, the Impression Sanjie Liu in southern China. More than 350 tourists’ spontaneous reviews posted on TripAdvisor were analyzed through Leximancer software. It was found that international tourists were generally positive toward the culturally distinctive style of the entertainment. Despite the challenge of comprehending meanings and the language, they were impressed with the grand spectacle, the performances of many people, and the context. The disruptive behavior of other tourists, particularly the domestic Chinese tourists, troubled some international tourists. Implications for both academic research and the tourism entertainment industry are offered.
Effect of intramuscular interferon beta-1a on gray matter atrophy in relapsing−remitting multiple sclerosis: A retrospective analysis
Authors: Fisher E , Nakamura K , Lee J-C , You X , Sperling B , Rudick RA
Published: August 2015

Background:

Changes in gray matter (GM) volume may be a useful measure of tissue loss in multiple sclerosis (MS).

Objectives:

To investigate the rate, patterns, and disability correlates of GM volume change in an MS treatment clinical trial.

Methods:

Patients ( n=140) with relapsing−remitting MS were randomized to intramuscular (IM) interferon (IFN) beta-1a or placebo. Treatment effects on GM fraction (GMF) and white matter (WM) fraction (WMF) changes, differences in rates of GMF and WMF change in year one and two on treatment, and differences in atrophy rates by disease progression status were assessed retrospectively.

Results:

Significantly less GM atrophy (during year two), but not WM atrophy (at any point), was observed with IM IFN beta-1a compared with placebo. Pseudoatrophy effects were more apparent in WM than in GM; in year one, greater WM volume loss was observed with IM IFN beta-1a than with placebo, whereas GM volume loss was similar between groups. Risk of sustained disability progression was significantly associated with GM, but not WM, atrophy.

Conclusions:

These results suggest that GMF change is more meaningful than WMF as a marker of tissue loss and may be useful to augment whole brain atrophy measurements in MS clinical trials.
Atrophy of reward-related striatal structures in fatigued MS patients is independent of physical disability
Authors: Damasceno Alfredo , Damasceno Benito Pereira , Cendes Fernando
Published: August 2015

Background:

MRI studies have shown gray-matter abnormalities in fatigued multiple sclerosis (MS) patients. However, given that physical disability is highly correlated to MS fatigue, it is often difficult to disentangle its effect in these MRI findings.

Objective:

The objective of this research paper is to investigate gray-matter damage in mildly disabled MS patients, addressing which variables were better related to fatigue while controlling for physical disability and depression.

Methods:

Forty-nine relapsing–remitting MS (RRMS) patients and 30 controls underwent MRI (3T). Fatigue was assessed using the Fatigue Severity Scale (FSS). Multivariate logistic regression was performed to assess the contribution of clinical and MRI metrics to fatigue. Statistical analyses were performed controlling for disability and depression.

Results:

Fatigue was present in 22 (44.9%) patients. FSS score was highly correlated with EDSS ( p = 0.00001). Patients with fatigue had lower brain cortical and subcortical gray-matter volumes. However, after controlling for EDSS, only the caudate and the accumbens volumes remained statistically significant.

Conclusions:

Fatigued MS patients have a global cortical and subcortical gray-matter atrophy that seems largely related to higher physical disability. However, striatal structures involved in effort-reward functions exhibited smaller volumes in fatigued patients, independently of physical disability and depressive symptoms, supporting the theory of cortico-striatal network impairment in MS fatigue.
Bullying-related behaviour in a mainstream high school versus a high school for autism: Self-report and peer-report
Authors: Begeer Sander , Fink Elian , van der Meijden Sandra , Goossens Frits , Olthof Tjeert
Published: August 2015

This study examined the frequency of bullying, victimisation and defending behaviours among children with autism spectrum disorder and normal intelligence, using both self-report and peer-report information. Peer-report and self-report data were collected on a single classroom of 26 early adolescent boys attending a special school for children with autism and compared with 23 typically developing boys attending a single mainstream secondary school. Results showed that self- and peer-reported bully and victimisation rates did not differ between boys with autism spectrum disorder and typically developing boys. However, self-reported defending behaviour was less likely to be reported by boys in the autism spectrum disorder school compared to boys in the mainstream school, although there was no such difference for peer-reported defending.
Book review: Choudry, A. and Kapoor, D., editors. 2013: NGOization: Complicity, contradictions and prospects
Authors: Ahmed Iqbal
Published: August 2015

Choudry, A. and Kapoor, D., editors. 2013: NGOization: Complicity, contradictions and prospects. London: Zed Books. 236 pp. £71.04 hardback, £19.99 paper, $17.99 e-book. ISBN: 9781780322582 hardback, 9781780322575 paperback.
The project implementation profile: A tool for enhancing management of NGO projects
Authors: Rusare Masiiwa , Jay C. Ian
Published: August 2015

This article argues for the use of the Project Implementation Profile (PIP) tool in managing non-governmental organization (NGO) projects. It applies the PIP to a project in the non-profit NGO sector and assesses the extent to which it provides project success assurance. The findings suggest that PIP can be used in this sector. Further work to refine the tool and integrate it with the Logical Framework is suggested.
Improving the credibility and effectiveness of non-governmental organizations
Authors: Amagoh Francis
Published: August 2015

As a part of the third-sector, non-governmental organizations (NGOs) are faced with issues of trust and accountability. Questions are increasingly being raised about how to make NGOs more accountable for the funds they receive and how to enhance their effectiveness and performance. This article examines the issues of trust and credibility of NGOs. The article identifies a number of factors that would help improve NGOs’ credibility, effectiveness and performance. Implications for third-sector organizations are discussed.
Federal government debt and economic growth: Evidence from Malaysia
Authors: Daud Siti Nurazira Mohd , Podivinsky Jan M.
Published: August 2015

This article conducts an investigation into the effect of federal government debt on Malaysia’s economic growth with the application of threshold regression. The result reveals that, beyond the government debt threshold level, the country is experiencing a positive effect on economic growth.
Using a smartphone app in qualitative research: the good, the bad and the ugly
Authors: García Borja , Welford Jo , Smith Brett
Published: August 2015

This article reflects on the use of a smartphone application (‘app’) in qualitative research following the experience of the FREE (Football Research in an Enlarged Europe) project, which investigated the lives of football fans in the UK. To meet this aim, a participant-focused audiovisual methodology was designed, featuring the use of an app to collect data. Fans were asked to take photographs and keep diaries to show the role football plays in their lives. The smartphone app was developed to allow fans to use their own mobile phones, capturing qualitative data in ‘real time’. The paper reflects on our experience of using the smartphone app in this qualitative research, analysing the advantages, disadvantages and the main risks that researchers will need to take into account when using smartphone apps in their future qualitative research projects. We encourage others to build on and advance this under-researched but potentially valuable tool.
Association of the angiotensinogen M235T polymorphism with recurrence after catheter ablation of acquired atrial fibrillation
Authors: Wang Qunshan , Hu Xiaofeng , Li Shuyuan , Wang Xiaofeng , Wang Jun , Zhang Rui , Sun Jian , Zhang Pengpai , Feng Xiangfei , Li Yi-Gang
Published: August 2015

Purpose:

Previous studies showed that genetic variants of the angiotensinogen ( AGT) gene conferred higher risk for acquired atrial fibrillation (AF). The present study investigated whether AGT variants correlate with the clinical outcome in patients with acquired AF after catheter ablation (CA).

Methods:

A total of 150 acquired symptomatic drug-refractory AF patients (mean age 63.7±11.0 years, 24.6% non-paroxysmal AF) with acquired AF underwent a single CA procedure in our department and were included in this retrospective analysis. Eight tagging single nucleotide polymorphisms (tSNPs) in the AGT gene were genotyped. Standard electrocardiographs (ECGs) and 24-hour Holter recordings were performed during a median follow-up period of 57.5 months to detect AF recurrence.

Results:

Sixty-one patients (40.7%) suffered AF recurrences after a single CA procedure during follow up. Of the eight tSNPs, the frequency of the M allele of M235T was significantly higher in the recurrence group (28%) compared to the non-recurrence group (18%) ( p=0.042). The recurrence rates of patients with the TT, MT, and MM genotypes were 34.4%, 50%, and 55.6%, respectively ( ptrend=0.049). After adjusting for age, sex, body mass index, hypertension, left atrial volume index (LAVI) and other covariates, M235T increased the risk of AF recurrence in additive and dominant models with odds ratios of 2.023 (95% confidence interval (CI): 1.034–3.926, p=0.033) and 2.601 (95% CI: 1.102–6.056, p=0.025), respectively. However, in multiple correction analyses, the p values of multiple comparisons were not statistically significant ( pcorrect>0.05).

Conclusions:

The M allele of M235T might be associated with an increased risk of AF recurrence after CA. Genotyping may thus be helpful on identifying patients with higher risks of AF recurrence after CA and developing optimal follow-up strategies. These strategies may differ and should be individualized according to patients’ genotype. Future studies are warranted to validate the potential effect of AGT M235T on AF recurrence post CA.
The blocking of angiotensin II type 1 receptor and RhoA/Rho kinase activity in hypertensive patients: Effect of olmesartan medoxomil and implication with cardiovascular-renal remodeling
Authors: Ravarotto Verdiana , Pagnin Elisa , Maiolino Giuseppe , Fragasso Antonio , Carraro Gianni , Rossi Barbara , Calò Lorenzo A
Published: August 2015

Hypothesis/Introduction:

The pathophysiological role of oxidative stress (OxSt) in hypertension and target organ damage is recognized. Angiotensin II (Ang II) induces OxSt via NAD(P)H oxidase activation and production of proinflammatory cytokines/growth factors leading to cardiovascular-renal remodeling. Ang II stimulates the RhoA/Rho kinase (ROCK) pathway, which is deeply involved in the development of cardiovascular-renal remodeling via OxSt induction. Olmesartan, an Ang II type 1 receptor blocker, possesses antioxidant and activating nitric oxide system-related effects, which we have shown in terms of p22phox reduction, heme oxygenase-1 and calcitonin gene-related peptide increase. This study evaluates in 15 untreated hypertensive patients the effect of olmesartan treatment on p63RhoGEF, key in Ang II-induced ROCK activation, and MYPT-1 phosphorylation, a marker of ROCK activity.

Materials and methods:

The p63RhoGEF protein level and MYPT-1 phosphorylation (Western blot) were evaluated at baseline, and after three and six months of olmesartan treatment.

Results:

Olmesartan normalized systolic and diastolic BP ( p < 0.001), reduced p63RhoGEF level: 1.3±0.25 d.u. (baseline) vs 1.0±0.29 (three months), p < 0.0001 vs 1.0±0.22, (six months), p < 0.0001 and MYPT-1 phosphorylation: 1.2 ±0.14 (baseline) vs 0.9±0.19 (three months), p = 0.008, vs 0.8±0.16 (six months), p = 0.001.

Conclusions:

These data added to our previous results further provide a mechanistic rationale for olmesartan’s antioxidant/anti-inflammatory potential translation, in the long term, toward anti-atherosclerotic/anti-remodeling effects reported by clinical trials.
The experiences of host country nationals in international schools: A case-study from Malaysia
Authors: Bailey Lucy
Published: August 2015

Although there has been considerable research into expatriate children attending international schools, there has been little investigation into children who attend international schools within their own nation. Seeking to redress this imbalance, this article analyses interview data from a small-scale study of host country nationals attending an international school in Malaysia, in order to examine the significance attached by them to international schooling, and contrasts these accounts with interviews conducted with their expatriate teachers.
Using international accreditation in higher education to effect changes in organisational culture: A case study from a Turkish university
Authors: Collins Ian
Published: August 2015

International accreditation is now a significant yet controversial issue in global higher education. This case study looked at the experience of an intensive English language preparatory programme within a university in Turkey going through an accreditation by a foreign institution, and assessed to what extent the project managed to foster changes in its organisational culture. While it was clear that most felt the accreditation had a significant impact, there was much less clear evidence of changes in organisational culture.
Envisioning world citizens? Self-presentations of an international school in Germany and related orientations of its pupils
Authors: Keßler Catharina , Krüger Heinz-Hermann , Schippling Anne , Otto Ariane
Published: August 2015

Against the backdrop of changes in global education, the German education system has undergone immense diversification. Many private schools are being founded, among them international schools catering both to an international clientele and to growing numbers of Germans. This article presents results from part of a qualitative longitudinal study on educational careers of young people and the role of peer cultures. The self-presentations of an international school centred on pupil support, lifelong learning and global citizenship are set in relation to the perspectives of their pupils in this context.
International HRD and Offshore Outsourcing
Authors: Anderson Valerie
Published: August 2015

Offshore outsourcing is an increasing trend in the global business environment and has important consequences for human resource development (HRD) practices such as organization development, knowledge transfer, organizational culture, and training and development. However, the links between international HRD (IHRD) and offshore outsourcing have yet to be explored in the HRD literature. This article argues that robust IHRD research into offshore outsourcing contexts is required that challenges the dominant “headquarters perspective” taken in existing accounts of the global trend to offshore outsourcing. To provide the basis for a research agenda, the article undertakes a conceptual review of the IHRD and offshore outsourcing literatures. It develops a conceptual framework that identifies connections between these fields as a basis for an IHRD research agenda to examine the HRD effects and contributions to offshore outsourcing arrangements for individuals and teams working in “provider” and “client” organizations and to investigate the consequences for HRD in both “home” and “destination” countries.
Ever and Annual Use of Prostate Cancer Screening in African American Men
Authors: Halbert Chanita Hughes , Gattoni-Celli Sebastiano , Savage Stephen , Prasad Sandip M. , Kittles Rick , Briggs Vanessa , Delmoor Ernestine , Rice LaShanta J. , Jefferson Melanie , Johnson Jerry C.
Published: August 2015

Since prostate cancer continues to disproportionately affect African American men in terms of incidence, morbidity, and mortality, prostate-specific antigen (PSA) screening plays an important role in early detection, especially when men engage in informed decision making to accept or decline this test. The authors evaluated utilization of PSA testing among African American men based on factors that are important components of making informed decisions. Utilization of PSA testing was evaluated based on whether men had ever had PSA testing and PSA testing during the past year in a community-based sample of African American men ages 50 to 75 ( n = 132). Overall, 64% of men ( n = 85) reported that they had ever had a PSA test; the mean ( SD) age for first use of PSA testing was 47.7 ( SD = 7.4). The likelihood of ever having a PSA test increased significantly with physician communication (odds ratio [OR] = 14.2; 95% confidence interval [CI] = 4.20, 48.10; p = .0001) and with having an annual household income that was greater than $20,000 (OR = 9.80; 95% CI = 3.15, 30.51; p = .0001). The odds of ever having a PSA test were also decreased with each unit increase in future temporal orientation (OR = 0.66; 95% CI = 0.47, 0.93; p = .02). Of the men who had ever had PSA testing, 57% were screened during the past year. Only health insurance status had a significant independent association with having annual PSA testing (OR = 5.10; 95% CI = 1.67, 15.60; p = .004). Different factors were associated significantly with ever having PSA testing and annual testing among African American men. African American men may not be making an informed decision about prostate cancer screening.
Human Bisphenol A Exposure and the “Diabesity Phenotype”
Authors: Bertoli Simona , Leone Alessandro , Battezzati Alberto
Published: August 2015

Bisphenol A (BPA), a known endocrine disruptor, is a food contaminant suspected of being a contributing factor to the present-day increase in obesity, diabetes, and cardiovascular disease. This issue is of increasing interest in the field of diabetes research and has become a matter of concern for regulatory agencies and food industries. Recently, the number of studies involving BPA has increased exponentially, but there are still many gaps in the knowledge of the relationship between actual BPA exposure and cardiometabolic risk and of the modalities of food intake exposure, all of which prevents sound judgments concerning the risks to human health. This review focuses on the association between human exposure to BPA and obesity, thyroid function, diabetes, insulin resistance, metabolic syndrome, cardiovascular diseases, and BPA content in food. Many cross-sectional studies support, sometimes contradictorily, an adverse effect of BPA exposure on obesity, diabetes, and cardiovascular diseases. Few prospective studies support an adverse effect of BPA exposure on such pathologies. Moreover, no intervention studies have been conducted to evaluate the causality of such associations. This is mainly due to lack of an appropriate database of BPA content in foods, thus hindering any estimation of the usual dietary BPA intake.
Making the next steps in psoriatic arthritis management: current status and future directions
Authors: Sritheran Diviya , Leung Ying Ying
Published: August 2015

Psoriatic arthritis (PsA) is a chronic inflammatory condition with articular and extra-articular manifestations: peripheral arthritis, axial disease, enthesitis, dactylitis, and skin and nail disease. It is associated with cardiovascular comorbidities. It is now recognized as a new entity, different from rheumatoid arthritis and other spondyloarthritis in terms of clinical manifestations, pathogenesis, and response to therapies. Anti-tumor necrosis factors (anti-TNFs) have demonstrated clinical efficacies exceeding that of conventional disease modifying antirheumatic drugs (DMARDs). The current treatment paradigms recommend early diagnosis and treatment, and a strategic and target orientated approach, aiming at a low disease activity status. New understanding in the immunopathogenesis of PsA has led to new treatment targets. This review addresses the evidence of current treatment for each of the domains as an aid to the clinician managing these patients in the clinic. Some new therapeutic targets are presented. We highlight the importance of development and validation in outcome measures, including that of composite scores that capture various disease domains that will facilitate future clinical trials to inform the best treatment.
Anaesthesia for goitre surgery: A review
Authors: Wong Patrick , Chieh Liew Geoffrey Haw , Kothandan Harikrishnan
Published: August 2015

Goitres are relatively common and, in extreme cases, present unique challenges (particularly in airway management) for the anaesthetist. There are no specific guidelines from the Difficult Airway Society (United Kingdom) or the American Society of Anesthesiologists for the management of the obstructed airway. We therefore present the principles governing the provision of safe anaesthesia for goitre surgery including formulating a plan ABC for patients with a stable airway and for those presenting with acute airway obstruction.
Babies and big boys: Power, desire and the politics of belonging in early childhood education and care
Authors: Stratigos Tina
Published: August 2015

Belonging is a fundamental human need that impacts young children’s everyday experiences and wellbeing in group care. We know little, however, about how belonging works for infants in multi-age settings such as family day care. In this article, I use Sumsion and Wong’s three intersecting axes of belonging – categorisation, performativity, and resistance and desire – to analyse two segments of video data from a longitudinal case study of belonging for an infant in family day care. I draw on concepts from Deleuze and Guattari, in particular assemblage and desire, to develop understandings of how the axes appeared to be at work and what they meant for the infant’s belonging at family day care. I am particularly interested in what an examination of the axes might reveal about the roles infants can play in the politics of belonging in early childhood education and care. The data illustrate the important role played by material aspects of assemblages, the dynamic nature of social categories and the complex roles of desire and power in the politics of belonging for infants.
‘Be careful!’ Using our words as a discursive exploration of early childhood educators regulating children’s play
Authors: Kenneally Noah
Published: August 2015

What early childhood educators say to children on playgrounds shapes children’s behaviour. ‘Be careful!’ may be the most common phrase uttered on playgrounds across Ontario, as early childhood educators manage children’s play and work to maintain their safety. These utterances, and the disciplinary practices that accompany them, shape what is acceptable and unacceptable for children to do and, ultimately, what kind of children they can be. Making use of analytic strategies derived from Foucault, I take some first steps to show that injunctions to ‘be careful’ and other similar utterances regulate children’s behaviour to produce a particular child-subject, while in the same moment revealing much about some of the discourses at work in the playgrounds of many early learning settings. I propose that these discourses – the discourses of safety, socialization and purposeful play, all embedded within an overarching developmental discursive framework – connect early childhood educators’ utterances and practices on playgrounds to concepts of discipline and governmentality. I also explore in this article how a Foucauldian perspective may provide educators a space to question established ideas regarding children and their play and explore new approaches for ensuring children’s safety without controlling them.
Early childhood care and education in a consumer society: Questioning the child–adult binary and childhood inequality
Authors: Lim Sirene May-Yin
Published: August 2015

Like many globalised urban cities, Singapore is a consumer society – a social system shaped by the production and consumption of commodities. Through a cultural studies framework, this article utilises ethnographic data of children’s peer culture to raise questions about the child–adult binary and developmentalism that tends to govern educational thought and practice in Singapore. Drawing from the talk and action of a group of 4- and 5-year-olds and parent interviews, this article sheds light on how a group of preschoolers and their families actively wrestle with similar processes of ‘being’ and ‘becoming’ within a consumer society, albeit in their own terms. In creating a peer culture of shared experiences, the children exchange personal facts and knowledge of cultural symbols, inadvertently including and excluding certain peers in such dialogues. This investigation reveals children’s creative appropriation of their family’s consumer culture in the process of connecting with peers. I pursue an argument emphasising the need for adults to acknowledge and respect young children as interpreters of societal culture and as agents in their own learning; to rethink assumptions of young children as ‘innocent’, ‘vulnerable’ and ‘incompetent’, and adults as ‘knowledgeable’ and ‘in control’.
Beauty and disability
Authors: Anderson David W
Published: August 2015

People often hold stereotypical notions about disability, assuming people with significant disabilities offer little in terms of friendship or contribution. Some are even repulsed by that person’s physical appearance. Such responses, evident within the Christian community as well, fail to acknowledge the inherent worth of the person as created in God’s image. Obviously harmful to the disabled, such attitudes also trap able-bodied persons within a normate bias, making difficult the successful inclusion of persons with disabilities in classrooms, churches, and communities. Beauty and the Beast is used to challenge these perceptions and point to the beauty of the disabled, made visible through “wholesight.” Personal acquaintance and anecdotal descriptions of persons with disabilities illustrate such beauty.
Two Helpful MRI Signs for Evaluation of Posterolateral Bundle Tears of the Anterior Cruciate Ligament
Authors: Volokhina Yulia V. , Syed Hasan M. , Pham Peter H. , Blackburn Allie K.
Published: August 2015

Background:

Diagnosis of partial anterior cruciate ligament (ACL) tears is difficult on magnetic resonance imaging (MRI), particularly the isolated tears of the posterolateral bundle.

Purpose:

To describe 2 MRI signs of partial ACL tear involving the posterolateral bundle on conventional knee MRI sequences, specifically, the “gap” and “footprint” signs.

Study Design:

Case-control study.

Methods:

We retrospectively reviewed the MRI appearance of the ACL in 11 patients with arthroscopically proven partial ACL tears isolated to the posterolateral bundle, as well as in 10 patients with arthroscopically proven intact ACLs, and evaluated for the presence of gap and/or footprint signs.

Results:

There was high degree of sensitivity and specificity associated with the MRI findings of “gap” and “footprint” signs with arthroscopically proven isolated posterolateral bundle tears.

Conclusion:

Gap and footprint signs are suggestive of posterolateral bundle tear of the ACL, and the presence of 1 or both of these imaging findings should alert the radiologist to the possibility of a posterolateral bundle tear.
Outcomes 2 Years After ACLR In Athletes
Authors: Failla Mathew , Logerstedt David , Grindem Hege , Axe Michael J. , Engebretsen Lars , Risberg May Arna , Snyder-Mackler Lynn
Published: August 2015

Objectives:

At least 175,000 Anterior Cruciate Ligament Reconstructions (ACLR) are performed yearly in the United States, with the goal of restoring static knee stabilization for full return to previous level of function. Large data registries have reported general population outcomes after ACLR, but less is known about the athletic population. The purpose of this study is to evaluate functional outcomes, return to sport rates, and re-injury rates 2 years after ACLR from an all athlete cohort and make comparisons to outcomes reported in the literature.

Methods:

Three hundred subjects were prospectively enrolled after ACL injury. All subjects sustained an isolated ACL injury and were enrolled within 7 months of injury. Subjects regularly participated in level I or II sports greater than 50 hours per year. All subjects underwent preoperative neuromuscular training. 201 of these subjects underwent ACLR. 157 patients returned for follow-up 2 years after surgery for performance-based and patient-reported testing. Quadriceps strength testing was completed either isometrically or isokinetically using an electromechanical dynamometer, and reported as quadriceps index (QI) [involved/uninvolved x 100]. Patient reported measures included The International Knee Documentation Committee 2000 Subjective Knee Form (IKDC2000), return to pre-injury activity (RTS), return to pre-injury activity competitive level (RTS-L), and re-injury. Statistics are expressed in means and standard deviations with T-tests or Chi-square for comparisons with values reported in literature.

Results:

Two year follow up QI (mean±SD: 96.94±13.4%) revealed significantly higher quadriceps index compared to Hamada 2001 (89.8±16.5%) ( P<.001). IKDC2000 (90.40±11.0; median: 94) scores were higher than the median score reported by the MOON group at 2 years (median: 75). Our RTS (72%) was significantly higher than Arden et al. 2014 (65%) ( P=.012), whereas, our RTS-L (55%) was similar to Arden 2014 (55%) ( P=.997). Our Re-injury rate was 13.9% (19 ipsilateral, 9 contralateral) which was significantly less (P=.002) than Paterno 2014 (29.5%).

Conclusion:

A comprehensive pre-operative rehabilitation program including neuromuscular training, combined with a post-operative rehabilitation program resulted in higher quadriceps strength, return to sport rates, and re-injury rates in athletes 2 years after ACLR compared to recent findings in the scientific literature. These findings highlight that despite excellent clinical outcomes, ACLR does not guarantee return to sport, and re-injury rates remain high. Limitations include motivational differences in athletes compared to general populations as well as age differences compared to Paterno 2014. Further research is needed to determine how to improve return to sport competitive levels rates and reduce subsequent injury risk in athletes after ACLR.
Do Ankle Sleeves And Lace-Up Braces Effect Neuromuscular Control And Athletic Performance?
Authors: Bodendorfer Blake , Stover Gary , James Christopher Ryan , Arnold Nicholas R. , Summerhays Ben , Gray Aaron D. , Sherman Seth Lawrence
Published: August 2015

Objectives:

Athletes commonly wear fitted silicone ankle sleeves (SAS) and lace-up ankle braces (LAB). There is limited data about their effect on neuromuscular control or athletic performance. Our goal is to evaluate their efficacy in a young, active population during athletic tasks using motion analysis.

Methods:

Ten subjects (5 males, 5 females) without prior musculoskeletal injury were recruited. They were asked to perform the Drop Vertical Jump test (DVJ), 45 degree bound, and cutting maneuvers under three conditions: No brace, SAS, LAB. DVJ was used as a surrogate for neuromuscular control, and the 45 degree bound and cutting for athletic performance. Tasks were performed in separate sessions to minimize effects of fatigue. Markerless motion-capture technology was used for data collection. For the DVJ, knee flexion, hip internal rotation, and dynamic valgus were measured during both contact and loading phases of landing. Ankle torque and range of motion were also evaluated. For the 45 degree bound, ankle torque was measured during the initial movement to the dominant knee. Performance time for the cutting with the dominant pivot foot was recorded. Statistics were calculated using a two-tailed Student's t-test with significance set at p=0.05.

Results:

When compared to controls for both the contact and loading phases of the DVJ, use of the SAS or LAB demonstrated significantly decreased hip internal rotation (67%, 15%, respectively), ankle torque (13%, 11% respectively), and ankle range of motion (p<0.01). Knee flexion was increased at initial contact in both the SAS and LAB groups compared to control (p<0.01). There was no significant effect of the braces on dynamic knee valgus, and no differences detected between the SAS and LAB on all parameters. When compared to controls for the 45 degree bound, ankle torque was significantly reduced for subjects wearing either SAS or LAB (24%, 13.5% respectively, p<0.01). The use of SAS or LAB had no significant effect on timed cutting maneuver vs. controls (p=0.1181, p=0.1124 respectively). There were no differences detected between the SAS and LAB for all parameters. See Figure 1 for results.

Conclusion:

Athletes wearing ankle sleeves and lace-up braces demonstrated improvements in neuromuscular control during the DVJ (decreased hip internal rotation, increased knee flexion at initial contact), decreased ankle torque during 45 degree bounding maneuvers, and no performance time deficit versus control during cutting maneuvers. There were no differences detected in either neuromuscular control or athletic performance between the brace types. The effect that these findings have on the incidence of lower extremity injury remains largely unknown and requires further investigation.
The Use of Micronized Allograft Articular Cartilage (BioCartilage) and Platelet Rich Plasma to Augment Marrow Stimulation in an Equine Model of Articular Cartilage Defects
Authors: Cole Brian J. , Fortier Lisa A. , Cook James L. , Cross Jessica , Chapman Hannah-Sophie , Roller Brandon
Published: August 2015

Objectives:

Microfracture continues to be a dominant treatment strategy for symptomatic articular cartilage defects. Improving the histologic and clinical outcomes with biologic adjuncts offers promise to enhance this widely utilized technique. Specifically, the use of a novel scaffold that is potentially conductive and inductive such as micronized allograft articular cartilage (BioCartilage-BC) combined with platelet rich plasma (PRP) was investigated as an adjunct to microfracture in an equine model of articular cartilage defects.

Methods:

Five adult horses were anesthetized and 2 - 10mm diameter full thickness cartilage defects were created in the trochlear ridge in both knees; one proximal (high load) and another distal (low load). In one knee, microfracture (MFx) followed by grafting with BioCartilage(BC). BioCartilage was mixed with PRP and injected into the defect with a touhey needle and sealed with fibrin under CO2 arthroscopy. The opposite limb served as a control and received MFx only. Horses were euthanized at 13 months post-operatively. Outcome was assessed with serial arthroscopy, 3T T2 and T1rho MRI, microCT, and histology. Statistics were performed using a mixed effect model with response variable contrasts. P≤0.05 was considered significant.

Results:

No complications such as joint inflammation, infection or lameness were encountered. The score for overall repair (12=normal, 0=complete degeneration) in both the proximal and distal defects was significantly better in the BC group compared to MFx (proximal BC 7.4±0.51, MFx 4.8±.1; p=0.041)(distal BC 5.6±0.98, MFx 2.6±1.5; p=0.022). All significant findings on histology (100=normal, o=complete degeneration) were confined to the proximal, high load defects. Graft perimeter integration (BC 96±8.9, MFx 68±19; p=0.02), graft base integration (BC 100+/- 0.0, MFx 70±37;p=0.044), subchondral bone architecture under the graft (BC 66±18, MFx 34±16; p=0.050) and collagen type II BC 82+/-8, MFx 58±11; p=0.051. There were no significant differences between BC and MFx in MRI or uCT analyses.

Conclusion:

Micronized allograft articular cartilage (BioCartilage) and PRP improve cartilage repair compared to marrow stimulation alone in an equine model of articular cartilage defects. This technology offers promise for the use of homologous allograft tissue as a low-cost and safe augmentation procedure for traditional microfracture surgery.
The Effect of Recombinant Human Parathyroid Hormone (rhPTH) on Tendon-to-Bone Healing in a Rat Rotator Cuff Model
Authors: Duchman Kyle R. , Goetz Jessica , Hettrich Carolyn M.
Published: August 2015

Objectives:

Successful rotator cuff tendon repair is predicated upon secure tendon-to-bone healing. A recent study has shown that recombinant human parathyroid hormone (rhPTH) treatment results in improved tendon-to-bone healing at the latter stages of healing, but not at early time points. We hypothesized that delaying administration of rhPTH until after the acute inflammatory phase would improve tendon-to-bone healing at all time points in a rat rotator cuff repair model.

Methods:

One hundred and eight male Sprague Dawley rats underwent detachment and subsequent repair of the supraspinatus tendon based on an a priori power analysis. Fifty four rats underwent repair alone and 54 rats received repair plus daily subcutaneous injections of 10 µg/kg of rhPTH beginning on postoperative day 7 and continuing for 12 weeks. Rats were sacrificed at 2 and 16 weeks postoperatively for biomechanical testing or histologic and immunohistochemical analysis. Histologic slides were digitized, and the enthesis was evaluated quantitatively using NIH Image J and VisioMorph software.

Results:

At 2 weeks postoperatively, the rhPTH group had significantly higher load to failure than the control group (10.85 versus 5.16 N; p = 0.003). At 16 weeks, there was no significant difference in load to failure between the two groups (Figure 1). With respect to stiffness of the repair, there was no significant difference between the two groups at either time point, but there was a trend toward increased stiffness in the rhPTH group at 2 weeks postoperatively compared to the control group (5.09 vs. 3.77 N/mm; p = 0.12). Histologically, the rhPTH specimens had more fibrocartilage and osteoblasts at all time points, with significantly better collagen fiber orientation at 2 weeks.

Conclusion:

Administration of rhPTH significantly increased load to failure at 2 weeks postoperatively in a rat rotator cuff repair model, with improved collagen fiber organization and increased fibrocartilage formation. Delaying administration of rhPTH until postoperative day number 7, after the resolution of the acute inflammation from surgery had subsided, improved rotator cuff healing in the early postoperative period while maintaining later-stage mechanical strength.
The Effects of Latarjet Reconstruction on Glenohumeral Instability in the Presence of Combined Bony Defects
Authors: Patel Ronak Maneklal , Walia Piyush , Gottschalk Lionel , Jones Morgan H. , Fening Stephen D. , Miniaci Anthony
Published: August 2015

Objectives:

Recurrent glenohumeral instability is often as a result of underlying bony defects in the glenoid and/or humeral head. Anterior glenoid augmentation with a bone block (i.e. Latarjet) has been recommended for glenoid bone loss in the face of recurrent instability. However, no study has investigated the effect of Latarjet augmentation in the setting of both glenoid and humeral head defects (Hill-Sachs Defects (HSD)). The purpose of this study was to evaluate the stability achieved through a Latarjet procedure in the presence of combined bony defects.

Methods:

Eighteen fresh-frozen cadaveric specimens were tested at all combinations of glenohumeral abduction (ABD) angles of 20°, 40°, and 60° and three external rotation (ER) levels (0°, 40°, and 80°). Each experiment comprised of anterior dislocation by translating the glenoid under a 50N medial load applied on the humerus, simulating the static load of soft tissues. Translational distance and medial-lateral displacement of the humeral head, along with horizontal reaction forces were recorded for every trial. Specimens were tested in an intact condition (no defect), different combinations of defects, and with Latarjet augmentation. The Latarjet was performed for 20% and 30% glenoid defects by transferring the specimen's coracoid process anterior to the glenoid flush with the articulating surface. Four different humeral head defects were created of sizes 6%, 19%, 31%, and 44% of humeral diameter. Repeated measures analysis of variance (ANOVA) was performed with statistical significance set at p <0.05.

Results:

Results are summarized in Fig. 1. The vertical axis represents the normalized distance to dislocation with respect to the values of the intact joint. The horizontal axis represents the varying sizes and combinations of bony defects. At 20° ABD and 0°ER, increasing HSD size did not affect percentage of intact translation with a constant glenoid defect of 20% before and after Latarjet augmentation (Fig. 1A). However, at an arm position of 60° ABD and 80° ER increasing HSD size led to a decrease in stability for both the defect state and post-Latarjet trials (Fig. 1B). Nevertheless, Latarjet augmentation helped in regaining stability for every combination of bony defects. With a HSD size of 44% the defect state had 0% intact translation for all 18 specimens.

Conclusion:

Clinically, these results demonstrate that some degree of stability can be regained for combined bony Bankart and Hill-Sachs defects with a Latarjet procedure. However, for humeral defects larger than 30%, the rotational effect of the HSD led to persistent instability. Thus, directly addressing the humeral defect to restore the articular surface should be considered in these cases. In conclusion, this study demonstrated that Latarjet procedure can restore the stability for combined defects, however for humeral defects greater than 31% may need attention.
Clinical Outcomes Following Revision Anterior Shoulder Stabilization
Authors: Frank Rachel M. , Mellano Chris , Shin Jason J. , Feldheim Terrence F. , Mascarenhas Randhir , Yanke Adam Blair , Cole Brian J. , Nicholson Gregory P. , Romeo Anthony A. , Verma Nikhil N.
Published: August 2015

Objectives:

The purpose of this study was to determine the clinical outcomes following revision anterior shoulder stabilization performed either via all-arthroscopic soft tissue repair or via Latarjet coracoid transfer.

Methods:

A retrospective review of prospectively collected data on 91 shoulders undergoing revision anterior shoulder stabilization was performed. All patients underwent prior soft tissue stabilization; those with prior open bone grafting procedures were excluded. For patients with 25% glenoid bone loss, Latarjet was performed (n=28). Patients were queried regarding recurrent instability (subluxation or dislocation). Clinical outcomes were evaluated using validated patient reported outcome questionnaires including the American Shoulder and Elbow Surgeons (ASES) score, Simple Shoulder Test (SST), visual analog scale (VAS) for pain, and Western Ontario Shoulder Instability Index (WOSI).

Results:

A total of 63 shoulders in 62 patients (46 males, 16 females) with an average age of 23.2 ± 6.9 years were included in the revision arthroscopy group. At an average follow-up of 46.9 ± 16.8 months (range, 15 to 78), the mean WOSI score was 80.1 (range, 15.0 to 100), and there were significant improvements (p<0.001) in ASES (63.7 to 85.1), SST (6.2 to 9.1), and VAS pain scores (2.89 to 0.81). Recurrent instability occurred in 12 of 63 shoulders (19%); the number of prior surgeries and baseline hyperlaxity were significant risk factors for failure (p<0.001 and p=0.04, respectively). No patients developed clinical or radiographic evidence of arthritis. A total of 28 shoulders in 28 patients (21 male, 7 female) with an average age of 27.5 years (range 14 to 45) were included in the Latarjet group. Thirteen (46%) had more than one previous stabilization attempt. ), the average WOSI score was 71.9, and there were significant improvements (p<0.001) in ASES (65.7 to 87.0), SST (7.2 to 10.3), and VAS (3.1 to 1.1). Recurrent instability occurred in 2 of 28 shoulders (7%), including 1 patient with symptomatic subluxation and 1 patient with a recurrent dislocation resulting in rapid arthrosis requiring revision to hemiarthroplasty at 20 months after Latarjet.

Conclusion:

Both arthroscopic revision stabilization and Latarjet coracoid transfer result in satisfactory outcomes in patients who have failed previous arthroscopic capsulolabral repair. Recurrent instability rates were higher in the all-arthroscopic group (19% versus 7%). Longer-term studies are required to determine whether similar results are maintained over time, and to provide guidance on focused clinical indications for this challenging patient population.