bluuebunny/crossref_metadata_2025 huggingface dataset:
Zeros of some special entire functions
Authors: Baricz Árpád , Singh Sanjeev
Published: August 2017

The real and complex zeros of some special entire functions such as Wright, hyper-Bessel, and a special case of generalized hypergeometric functions are studied by using some classical results of Laguerre, Obreschkhoff, Pólya, and Runckel. The obtained results extend the known theorem of Hurwitz on the exact number of nonreal zeros of Bessel functions of the first kind. Moreover, results on zeros of derivatives of Bessel functions and the cross-product of Bessel functions are also given, which are related to some recent open problems.
FIRE: functional inference of genetic variants that regulate gene expression
Authors: Ioannidis Nilah M , Davis Joe R , DeGorter Marianne K , Larson Nicholas B , McDonnell Shannon K , French Amy J , Battle Alexis J , Hastie Trevor J , Thibodeau Stephen N , Montgomery Stephen B , Bustamante Carlos D , Sieh Weiva , Whittemore Alice S
Published: August 2017

Motivation

Interpreting genetic variation in noncoding regions of the genome is an important challenge for personal genome analysis. One mechanism by which noncoding single nucleotide variants (SNVs) influence downstream phenotypes is through the regulation of gene expression. Methods to predict whether or not individual SNVs are likely to regulate gene expression would aid interpretation of variants of unknown significance identified in whole-genome sequencing studies.

Results

We developed FIRE (Functional Inference of Regulators of Expression), a tool to score both noncoding and coding SNVs based on their potential to regulate the expression levels of nearby genes. FIRE consists of 23 random forests trained to recognize SNVs in cis-expression quantitative trait loci (cis-eQTLs) using a set of 92 genomic annotations as predictive features. FIRE scores discriminate cis-eQTL SNVs from non-eQTL SNVs in the training set with a cross-validated area under the receiver operating characteristic curve (AUC) of 0.807, and discriminate cis-eQTL SNVs shared across six populations of different ancestry from non-eQTL SNVs with an AUC of 0.939. FIRE scores are also predictive of cis-eQTL SNVs across a variety of tissue types.

Availability and implementation

FIRE scores for genome-wide SNVs in hg19/GRCh37 are available for download at https://sites.google.com/site/fireregulatoryvariation/.

Supplementary information

Supplementary data are available at Bioinformatics online.
Plato’s Phaedo
Authors: Ebrey David
Published: August 2017

Plato’s Phaedo is set on the last day of Socrates’ life, ending with his moving death scene. The dialogue is one of Plato’s literary masterpieces, with classic discussions of forms, the immortality of the soul, and the value of the philosophical life. It is typically considered one of Plato’s middle-period dialogues due to its contrast between forms and sensible things, defense of the immortality of the soul, interest in natural science, and engagement with Pythagorean ideas. The primary interlocutors are Socrates, Simmias, and Cebes. Early in the dialogue, Socrates suggests that the poet Evenus should follow him in death. This shocks Simmias, leading Socrates first to defend the claim that a philosopher’s soul would be better separated from its body, and then the claim that the soul is immortal. Socrates’ four arguments for the immortality of the soul rely on considerations about the nature of change, causation, and the contrast between forms and sensible things. The two parts of the Phaedo that have received the most scholarship since the 1950s—among the most scholarship on any topic in ancient philosophy—are Socrates’ second argument for immortality, the Recollection Argument, which discusses central issues in Plato’s metaphysics and epistemology, and the so-called Autobiographical Section, which discusses Socrates’ earlier interest in natural science, the method of hypothesis, and his approach to providing causes. The dialogue ends with a long myth followed by Socrates’ death scene. For more on Plato, see the separate Oxford Bibliographies in Classics article “Plato.”
Political Economy of India
Authors: Sinha Aseema
Published: August 2017

Independent India is seventy years old (1947–2017) and may be the fastest-growing economy in the world. Yet, poverty, inequalities, and digital divides continue to bedevil the Indian economy. This combined paradox of economic success and deprivation for many makes the study of Indian political economy complex, interesting, and consequential. Academic assessment of India affects the lives and livelihood of millions of people. India and South Asia are engaged in a consequential “human drama,” an evocative phrase used by Gunnar Myrdal (see Myrdal 1968, cited under Political Economy of the Nehruvian State). What could be more important to study? Every economic and social analysis of India needs to be based in an understanding of the background of politics and economics, especially their intersections. If we talk of economic growth, we need to simultaneously bring in our understanding of the basis of that growth or the issues of distributional impact. Almost all economic challenges faced by a developing and poor yet growing economy bring political and economic questions and facts to the fore. Political economy is at the heart of India and its ongoing developmental trajectory. Political economy analysis of India, therefore, spans a fascinating set of debates and scholarly issues. More recently, as the Indian economy has become more complex, new approaches, questions, and literature have emerged, making the study of India’s political economy a large, productive, and sprawling field. This collection of relevant citations starts with general books, which are large topic-based compendiums and edited volumes covering a large range of material and themes. They are good starting points for any researcher, as they bring together a number of authors and approaches under one book cover. India’s developmental trajectory can be broken into two broad phases. The first of these is the Nehruvian period, which, it could be argued, lasted until 1991. Then, in 1991, sustainable economic reforms set India onto a new growth path. The logic of the origins of reforms must be distinguished from the logic of the sustainability of reforms. Thus, the reform period 1985–current can be broken into two separate phases. This article is organized according to the following structure. The first section focuses on General Overviews of India’s politics and political economy. The next section focuses on the Political Economy of the Nehruvian State, which underlies the Nehruvian model of development. Some thematic subsections are also interspersed: Agrarian Political Economy and Regional Political Economy and Federalism apart from class and societal analysis of the liberalization period. Then, the rest of the bibliographic paper is organized by the different phases of the Political Economy of Economic Reforms in India, including Recent Monographs on Political Economy, the Reforms of the 1980s, and the Reforms of the 1990s, followed by more thematic subsections. A separate subsection is devoted to policy and institutional studies and Class Analysis, Labor, and Politics of Reforms.
Trade and Development in International Law
Authors: Côté Charles-Emmanuel
Published: August 2017

The intersection between trade and development in international law appeared in the wake of the decolonization movement, in the second half of the 20th century. Newly independent states joined the older Latin American republics in the shared awareness of their underdevelopment and identified themselves as the Third World, most notably after the landmark Bandung conference of 1955. Developing countries soon gained majority in the UN General Assembly and tried to reshape the rules of international law in order to restore fairness in the multilateral trading system. Its governing instrument, the General Agreement on Tariffs and Trade (GATT), was perceived as fundamentally flawed since it did not address development and the typical economic issues associated with it. The organization of the first UN Conference on Trade and Development (UNCTAD) in 1964 and its establishment as an organ of the General Assembly were instrumental in the proposal of rules to take developing countries into account in international trade law. The GATT incorporated special and differential treatment (S&DT) provisions for developing countries, and other legal regimes were created to deal with issues of specific interest to them, such as international trade in commodities. This process culminated with the attempt by developing countries to establish a New International Economic Order (NIEO) in the 1970s. The NIEO agenda was dominant on the international stage and in legal thinking on trade and development until the early 1990s. International recognition of a right to development connected the topic of trade and development with the field of human rights. The establishment of the World Trade Organization (WTO) in 1995 and globalization profoundly shook the foundations of the rules governing trade and development. It marked a paradigmatic shift in international law, where trade liberalization came largely to be seen as the key to development. Renewed critical theories emerged fleshing out Third World approaches to international law, dealing notably with trade-related issues. The topic of trade and development remains relevant in early-21st-century international law, as exemplified by the Doha Development Round of multilateral trade negotiations and by the fact that most WTO members still identify as developing countries in the world trading system. The need to further address the issues faced by developing countries remains pressing. The topic of trade and development focuses on North-South or South-South trade relations and must be disambiguated from the concept of sustainable development. The latter does not deal specifically with developing countries and refers to development that meets current needs without compromising the ability of future generations to meet their own.
Expropriation in International Investment Law
Authors: Baetens Freya
Published: August 2017

Expropriation is the taking of foreign property by a state, whether for public purposes or other reasons. Historic instances of expropriation included outright takings of property, but nowadays expropriation is most commonly a result of indirect governmental measures that have the equivalent effect of a formal taking of property. International law protecting foreigners from the taking of their property began to be incorporated into treaties in the 19th and 20th centuries. Meanwhile, judicial pronouncements, particularly in the aftermath of World War II, paved the way for customary international law on this issue. This included the development of minimum standards for lawful taking of foreign property, including that expropriation must be for a public purpose; applied in a nondiscriminatory manner; carried out with due process of law; and accompanied by payment of prompt, adequate, and effective compensation. Nowadays, the international legal framework for regulating the right to take foreign property is largely contained in international investment agreements (IIAs). IIAs incorporate the minimum standards for lawful expropriatory measures developed in customary international law, but also provide additional rules on the types of property protected, requirements for such protection, and the actions from which property is protected. One of the biggest questions faced by international investment tribunals interpreting IIAs is the distinction between compensable indirect expropriations and legitimate, non-compensable regulatory measures. Arbitral tribunals are also yet to agree on principles for quantifying compensation and criteria for valuing expropriated property. Much of the literature in this article is devoted to these thorny issues.
Genotypic and Phenotypic Variations in Botrytis spp. Isolates from Single Strawberry Flowers
Authors: Hu Meng-Jun , Dowling Madeline E. , Schnabel Guido
Published: August 2017

Gray mold, caused by Botrytis spp., is among the most devastating diseases affecting strawberry worldwide. The great diversity present in the pathogen enhances its ability to survive and adapt in the field. In this study, we explored the genotypic and phenotypic diversity present in single strawberry flowers. In total, 192 isolates were collected from 19 flowers and four farms, and 9 to 12 isolates were collected from each flower. Forty-two haplotypes were found using microsatellite fragment analysis. Multiple haplotypes of two different Botrytis spp. (Botrytis cinerea and B. fragariae) were found in 12 flowers. In the remaining seven flowers, the single-spore isolates examined were of identical haplotypes. In three flowers, the two Botrytis spp. were found to coexist. Isolates were either sensitive (zero chemical class resistance) or resistant to one, two, three, four, or five chemical classes of fungicides. Resistance to multiple fungicides was commonly observed in both species but resistance to boscalid and penthiopyrad was only found in B. cinerea isolates. Resistance to cyprodinil was found in B. fragariae for the first time in the United States. Each haplotype was generally linked to a single resistance profile; however, a single resistance profile often was represented by multiple haplotypes. Isolates from the same flower of multiple haplotypes were largely identical in resistance profiles. This study is a first detailed investigation of genotypic diversity combined with phenotypic analysis of Botrytis spp. at the single-tissue level. It demonstrates that high genotypic and phenotypic diversity is present not only within fields but also in individual blossoms as well. This information is important for understanding the epidemiology of Botrytis and also has implications for fungicide resistance management, particularly related to resistance monitoring practices.
Combining Single Nucleotide Polymorphism Genotyping Array with Bulked Segregant Analysis to Map a Gene Controlling Adult Plant Resistance to Stripe Rust in Wheat Line 03031-1-5 H62
Authors: Wu Jianhui , Wang Qilin , Xu Liangsheng , Chen Xianming , Li Bei , Mu Jingmei , Zeng Qingdong , Huang Lili , Han Dejun , Kang Zhensheng
Published: August 2017

Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most devastating diseases of wheat worldwide. Growing resistant cultivars is considered the best approach to manage this disease. In order to identify the resistance gene(s) in wheat line 03031-1-5 H62, which displayed high resistance to stripe rust at adult plant stage, a cross was made between 03031-1-5 H62 and susceptible cultivar Avocet S. The mapping population was tested with Chinese P. striiformis f. sp. tritici race CYR32 through artificial inoculation in a field in Yangling, Shaanxi Province and under natural infection in Tianshui, Gansu Province. The segregation ratios indicated that the resistance was conferred by a single dominant gene, temporarily designated as YrH62. A combination of bulked segregant analysis (BSA) with wheat 90K single nucleotide polymorphism (SNP) array was used to identify molecular markers linked to YrH62. A total of 376 polymorphic SNP loci identified from the BSA analysis were located on chromosome 1B, from which 35 kompetitive allele-specific PCR (KASP) markers selected together with 84 simple sequence repeat (SSR) markers on 1B were used to screen polymorphism and a chromosome region associated with rust resistance was identified. To saturate the chromosomal region covering the YrH62 locus, a 660K SNP array was used to identify more SNP markers. To develop tightly linked markers for marker-assisted selection of YrH62 in wheat breeding, 18 SNPs were converted into KASP markers. A final linkage map consisting of 15 KASP and 3 SSR markers was constructed with KASP markers AX-109352427 and AX-109862469 flanking the YrH62 locus in a 1.0 cM interval. YrH62 explained 63.8 and 69.3% of the phenotypic variation for disease severity and infection type, respectively. YrH62 was located near the centromeric region of chromosome 1BS based on the positions of the SSR markers in 1B deletion bins. Based on the origin, responses to P. striiformis f. sp. tritici races, and marker distances, YrH62 is likely different from the other reported stripe rust resistance genes/quantitative trait loci on 1B. The gene and tightly linked KASP markers will be useful for breeding wheat cultivars with resistance to stripe rust.
The Decanal Divide: Women in Decanal Roles at U.S. Medical Schools
Authors: Schor Nina F.
Published: August 2017

Purpose

To test the hypotheses that women in medical school dean-level (decanal) positions occupy lower-rank and more image- and education-focused positions than men, and that state and woman-led schools have more women in decanal positions.

Method

Data were collected on September 10–18, 2016, from Web sites of 136 allopathic, U.S. medical schools accredited by the Liaison Committee on Medical Education and represented on the roster of accredited MD programs in the United States with full accreditation as of June 22, 2016. Statistical significance of differences between comparison groups was assessed using Student t test with P < .05 indicating significance. Correlation between parameters was determined by Spearman rank correlation test with P < .05 indicating significant correlation.

Results

Findings demonstrate that only 15% (22/149) of deans and interim deans are women, and the prevalence of women in decanal positions decreases with ascending professional rank (R
2 = 0.93; P < .05). Women are most prevalent in decanal positions focusing on education and mentoring or institutional public image and least prevalent in those focusing on corporate strategy and policy, finance, or government relations. Schools with a woman as dean or interim dean have a higher percentage of decanal positions occupied by women than those with a man as dean or interim dean (P < .05). State and private medical schools do not differ from one another in this regard.

Conclusions

Gender stereotypes and models appear to continue to drive the number and roles of women in decanal positions.
Can We Increase the Value and Decrease the Cost of Clinical Skills Assessment?
Authors: Burdick William P. , Boulet John R. , LeBlanc Kim Edward
Published: August 2017

Although the authors do not agree with medical students’ bid to end the United States Medical Licensing Examination Step 2 Clinical Skills or Comprehensive Osteopathic Medical Licensing Examination Level 2-Performance Evaluation tests, they concur with Ecker and colleagues that conducting further research to support the validity argument, providing greater feedback on performance, and exploring options to reduce costs are important for addressing students’ concerns. Evidence to support the validity of clinical skills exam scores and associated inferences already exists. What is lacking, and would help further justify the use of these examinations, is more evidence to support the “extrapolation” argument—that is, is performance on these examinations related to actual patient care? Enhanced feedback on exam performance should also be considered. While performance data from licensing examinations should be used judiciously given the primary purpose of these tests, additional data would be helpful to learners and their institutions. Centralized testing remains the least costly design, but efficiencies of standardized patient training, case development, and scoring can be reviewed. Scoring modifications made in the past several years at substantial cost should be evaluated to determine whether they have achieved desired goals. Testing organizations can and should embrace these essential elements of transparency and accountability to address concerns about the value of clinical skills examinations.
Step Up—Not On—The Step 2 Clinical Skills Exam: Directors of Clinical Skills Courses (DOCS) Oppose Ending Step 2 CS
Authors: Ecker David J. , Milan Felise B. , Cassese Todd , Farnan Jeanne M. , Madigosky Wendy S. , Massie F. Stanford , Mendez Paul , Obadia Sharon , Ovitsh Robin K. , Silvestri Ronald , Uchida Toshiko , Daniel Michelle
Published: August 2017

Recently, a student-initiated movement to end the United States Medical Licensing Examination Step 2 Clinical Skills and the Comprehensive Osteopathic Medical Licensing Examination Level 2-Performance Evaluation has gained momentum. These are the only national licensing examinations designed to assess clinical skills competence in the stepwise process through which physicians gain licensure and certification. Therefore, the movement to end these examinations and the ensuing debate merit careful consideration. The authors, elected representatives of the Directors of Clinical Skills Courses, an organization comprising clinical skills educators in the United States and beyond, believe abolishing the national clinical skills examinations would have a major negative impact on the clinical skills training of medical students, and that forfeiting a national clinical skills competency standard has the potential to diminish the quality of care provided to patients. In this Perspective, the authors offer important additional background information, outline key concerns regarding the consequences of ending these national clinical skills examinations, and provide recommendations for moving forward: reducing the costs for students, exploring alternatives, increasing the value and transparency of the current examinations, recognizing and enhancing the strengths of the current examinations, and engaging in a national dialogue about the issue.
Barriers to Career Flexibility in Academic Medicine: A Qualitative Analysis of Reasons for the Underutilization of Family-Friendly Policies, and Implications for Institutional Change and Department Chair Leadership
Authors: Shauman Kimberlee , Howell Lydia P. , Paterniti Debora A. , Beckett Laurel A. , Villablanca Amparo C.
Published: August 2017

Purpose

Academic medical and biomedical professionals need workplace flexibility to manage the demands of work and family roles and meet their commitments to both, but often fail to use the very programs and benefits that provide flexibility. This study investigated the reasons for faculty underutilization of work–life programs.

Method

As part of a National Institutes of Health–funded study, in 2010 the authors investigated attitudes of clinical and/or research biomedical faculty at the University of California, Davis, toward work–life policies, and the rationale behind their individual decisions regarding use of flexibility policies. The analysis used verbatim responses from 213 of 472 faculty (448 unstructured comments) to a series of open-ended survey questions. Questions elicited faculty members’ self-reports of policy use, attitudes, and evaluations of the policies, and their perceptions of barriers that limited full benefit utilization. Data were coded and analyzed using a grounded theory approach.

Results

Faculty described how their utilization of workplace flexibility benefits was inhibited by organizational influences: the absence of reliable information about program eligibility and benefits, workplace norms and cultures that stigmatized program participation, influence of uninformed/unsupportive department heads, and concerns about how participation might burden coworkers, damage collegial relationships, or adversely affect workflow and grant funding.

Conclusions

Understanding underuse of work–life programs is essential to maximize employee productivity and satisfaction, minimize turnover, and provide equal opportunities for career advancement to all faculty. The findings are discussed in relation to specific policy recommendations, implications for institutional change, and department chair leadership.
Characterizing the Age and Stimulus Frequency Interaction for Ocular Vestibular-Evoked Myogenic Potentials
Authors: Singh Niraj Kumar , Firdose Husna
Published: August 2017

Objectives:

The normal process of aging is mostly associated with global decline in almost all sensory aspects of the human body. While aging affects the 500-Hz tone burst–evoked ocular vestibular-evoked myogenic potentials (oVEMPs) by reducing the amplitudes and prolonging the latencies, its interaction with oVEMP responses at other frequencies has not been studied. Therefore, the present study aimed at investigating the impact of advancing age on the frequency tuning of oVEMP.

Design:

Using a cross-sectional research design, oVEMPs were recorded for tone burst frequencies of 250, 500, 750, 1000, 1500, and 2000 Hz from 270 healthy individuals divided into six age groups (10–20, 20–30, 30–40, 40–50, 50–60, and >60 years).

Results:

The results revealed significantly lower response rates and amplitudes in age groups above 50 years of age than all the other groups at nearly all the frequencies (p < 0.05). Further, the frequency tuning was obtained at 500 or 750 Hz in majority of individuals below 60 years of age and at ≥1000 Hz in most of the individuals above 60 years of age (p < 0.05). Thus, there was a significant shift in frequency tuning of oVEMP from 500 or 750 Hz in the younger and the middle-aged adults to ≥1000 Hz in older adults, especially above 60 years of age.

Conclusions:

The results of the study showed significantly higher prevalence of frequency tuning at 1000 Hz in older adults above 60 years of age. Because the shift in frequency tuning to ≥1000 Hz is frequently used for identification of Meniere’s disease, it is suggested that age-related correction be used for the diagnosis of Meniere’s disease when using frequency tuning of oVEMP.
Application of AOSpine Subaxial Cervical Spine Injury Classification in Simple and Complex Cases
Authors: Aarabi Bizhan , Oner Cumhur , Vaccaro Alexander R. , Schroeder Gregory D. , Akhtar-Danesh Noori
Published: August 2017

Introduction:

Cervical spine injury classification systems should be simple, easy to relate and remember, reliable guide for surgical planning, and predictor of outcome in clinical settings. We investigated whether the AOSpine subaxial cervical spine classification system predicted injury severity and neurologic outcome.

Material and Methods:

We analyzed the relevant clinical, imaging, management, and American Spinal Injury Association (ASIA) impairment scale (AIS) grade conversion of 92 AIS grades A–C patients with cervical spine injury. We correlated morphology class with age, injury severity score (ISS), follow-up ASIA motor score (AMS), intramedullary lesion length (IMLL), and AIS grade conversion at 6 months after injury.

Results:

The mean age of patients was 39.3 years, 83 were men, and 69 were injured during an automobile accident or after a fall. The AOSpine class was A4 in 8, B2 in 5, B2A4 in 16, B3 in 19, and C in 44 patients. The mean ISS was 29.7 and AMS was 17.1. AIS grade was A in 48, B in 25, and C in 19 patients. Mean IMLL on postoperative magnetic resonance imaging was 72 mm: A4 = 68.1; B2A4 = 86.5; B2 = 59.3; B3 = 46.8; and C = 79.9. At a mean follow-up of 6 months, the mean AMS was 39.6. Compared to patients with class B3 injuries, those with class C injuries were significantly younger (P < 0.0001), had longer IMLL (P < 0.002), and were less likely to have AIS grade conversion to a better grade (P < 0.02).

Conclusions:

The AOSpine subaxial cervical spine injury classification system successfully predicted injury severity (longer IMLL) and chances of neurologic recovery (AIS grade conversion) across different class subtypes.
Does Surgical Intervention or Timing of Surgery Have an Effect on Neurological Recovery in the Setting of a Thoracolumbar Burst Fracture?
Authors: Kato So , Murray Jean-Christophe , Kwon Brian K. , Schroeder Gregory D. , Vaccaro Alexander R. , Fehlings Michael G.
Published: August 2017

Traumatic thoracolumbar burst fractures are one of the most common forms of spinal trauma with the majority occurring at the junctional area where mechanical load is maximal (AOSpine Thoracolumbar Spine Injury Classification System Subtype A3 or A4). Burst fractures entail the involvement of the middle column, and therefore, they are typically associated with bone fragment in the spinal canal, which may cause compression of the spinal cord, conus medullaris, cauda equina, or a combination of these. Fortunately, approximately half of the patients with thoracolumbar burst fractures are neurologically intact due to the wide canal diameter. Recent evidences have revealed that functional outcomes in the long term may be equivalent between operative and nonoperative management for neurologically intact thoracolumbar burst fractures. Nevertheless, consensus has not been met regarding the optimal treatment strategy for those with neurological deficits. The present review article summarizes the contemporary evidences to discuss the role of nonoperative management in the presence of neurological deficits and the optimal timing of decompression surgery for neurological recovery. In summary, although operative management is generally recommended for thoracolumbar fracture with significant neurological deficits, the evidence is weak, and nonoperative management can also be an option for those with solitary radicular symptoms. With regards to timing of operative management, high-quality studies comparing early and delayed intervention are lacking. Extrapolating from the evidence in cervical spine injury leads to an assumption that early intervention would also be beneficial for neurological recovery, but further studies are warranted to answer these questions.
Osteoporotic Thoracolumbar Fractures—How Are They Different?—Classification and Treatment Algorithm
Authors: Rajasekaran Shanmuganathan , Kanna Rishi M. , Schnake Klaus J. , Vaccaro Alexander R. , Schroeder Gregory D. , Sadiqi Said , Oner Cumhur
Published: August 2017

Osteoporotic vertebral fractures constitute at least 50% of the osteoporotic fractures that happen worldwide. Occurrence of osteoporotic fractures make the elderly patient susceptible for further fractures and increases the morbidity due to kyphosis and pain; the mortality risk is also increased in these patients. Most fractures occur in the thoracic and thoracolumbar region and are often stable. Different descriptive and prognostic classification systems have been described, but none are universally accepted. Radiographs, computed tomography, and magnetic resonance imaging are useful in imaging the fracture and evaluating the bone density. In acute stages, the fractures are well treated with conservative measures including short bed rest, analgesics, bracing, and exercises. Although most fractures heal well, up to 30% of fractures can develop painful nonunion, progressive kyphosis, and neurological deficit. For patients who develop severe pain not responding to nonoperative measures and painful nonunion, percutaneous cement augmentation procedures including vertebroplasty or kyphoplasty have been suggested. For fractures with severe collapse and that lead to neurological deficit and increasing kyphosis, instrumented stabilization is advised. Prevention and management of osteoporosis is the key element in the management of osteoporotic fractures in the elderly. Guidelines for essential adequate dietary and supplemental calcium and vitamin D, and antiosteoporotic medications have been described.
Spine Trauma—What Are the Current Controversies?
Authors: Oner Cumhur , Rajasekaran Shanmuganathan , Chapman Jens R. , Fehlings Michael G. , Vaccaro Alexander R. , Schroeder Gregory D. , Sadiqi Said , Harrop James
Published: August 2017

Although less common than other musculoskeletal injuries, spinal trauma may lead to significantly more disability and costs. During the last 2 decades there was substantial improvement in our understanding of the basic patterns of spinal fractures leading to more reliable classification and injury severity assessment systems but also rapid developments in surgical techniques. Despite these advancements, there remain unresolved issues concerning the management of these injuries. At this moment there is persistent controversy within the spinal trauma community, which can be grouped under 6 headings. First of all there is still no unanimity on the role and timing of medical and surgical interventions for patients with associated neurologic injury. The same is also true for type and timing of surgical intervention in multiply injured patients. In some common injury types like odontoid fractures and burst type (A3-A4) fractures in thoracolumbar spine, there is wide variation in practice between operative versus nonoperative management without clear reasons. Also, the role of different surgical approaches and techniques in certain injury types are not clarified yet. Methods of nonoperative management and care of elderly patients with concurrent complex disorders are also areas where there is no consensus. In this overview article the main reasons for these controversies are reviewed and the possible ways for resolutions are discussed.
Management of Hangman's Fractures: A Systematic Review
Authors: Murphy Hamadi , Schroeder Gregory D. , Shi Weilong J. , Kepler Christopher K. , Kurd Mark F. , Fleischman Andrew N. , Kandziora Frank , Chapman Jens R. , Benneker Lorin M. , Vaccaro Alexander R.
Published: August 2017

Background:

Traumatic spondylolisthesis of the axis, is a common cervical spine fracture; however, to date there is limited data available to guide the treatment of these injuries. The purpose of this review is to provide an evidence-based analysis of the literature and clinical outcomes associated with the surgical and nonsurgical management of hangman's fractures.

Methods:

A systematic literature search was conducted using PubMed (MEDLINE) and Scopus (EMBASE, MEDLINE, COMPENDEX) for all articles describing the treatment of hangman's fractures in 2 or more patients. Risk of nonunion, mortality, complications, and treatment failure (defined as the need for surgery in the nonsurgically managed patients and the need for revision surgery for any reason in the surgically managed patients) was compared for operative and nonoperative treatment methods using a generalized linear mixed model and odds ratio analysis.

Results:

Overall, 25 studies met the inclusion criteria and were included in our quantitative analysis. Bony union was the principal outcome measure used to assess successful treatment. All studies included documented fracture union and were included in statistical analyses. The overall union rate for 131 fractures treated nonsurgically was 94.14% [95% confidence interval (CI), 76.15–98.78]. The overall union rate for 417 fractures treated surgically was 99.35% (95% CI, 96.81–99.87). Chance of nonunion was lower in those patients treated surgically (odds ratio, 0.12; 95% CI, 0.02–0.71). There was not a significant difference in mortality between patients treated surgically (0.16%; 95% CI, 0.01%–2.89%) and nonsurgically (1.04%; 95% CI, 0.08%–11.4%) (odds ratio, 0.15; 95% CI, 0.01–2.11). Treatment failure was less likely in the surgical treatment group (0.12%; 95% CI, 0.01%–2.45%) than the nonsurgical treatment group (0.71%; 95% CI, 0.28%–15.75%) (odds ratio 0.07; 95% CI, 0.01–0.56).

Conclusion:

Hangman's fractures are common injuries, and surgical treatment leads to an increase in the rate of osteosynthesis/fusion without significantly increasing the rate of complication. Both an anterior and a posterior approach result in a high rate of fusion, and neither approach seems to be superior.
Patient Perceptions of the Use of Medical Marijuana in the Treatment of Pain After Musculoskeletal Trauma: A Survey of Patients at 2 Trauma Centers in Massachusetts
Authors: Heng Marilyn , McTague Michael F. , Lucas Robert C. , Harris Mitchel B. , Vrahas Mark S. , Weaver Michael J.
Published: August 2017

Objective:

To evaluate musculoskeletal trauma patients' beliefs regarding the usefulness of marijuana as a valid medical treatment for postinjury and postoperative pain and anxiety.

Design:

Prospective survey.

Setting:

Two academic Level 1 trauma centers.

Patients/Participants:

Five hundred patients in an orthopedic outpatient clinic.

Intervention:

Survey.

Main Outcome Measurements:

(1) Do patients believe that marijuana can be used as medicine? (2) Do patients believe that marijuana can help treat postinjury pain? (3) Are patients comfortable speaking with their health care providers about medical marijuana?

Results:

The majority of patients felt that marijuana could be used to treat pain (78%, 390) and anxiety (62%, 309). Most patients (60%, 302) had used marijuana at least once previously, whereas only 14% reported using marijuana after their injury. Of those who used marijuana during their recovery, 90% (63/70) believed that it reduced symptoms of pain, and 81% (57/70) believed that it reduced the amount of opioid pain medication they used.

Conclusions:

The majority of patients in this study believed that medical marijuana is a valid treatment and that it does have a role in reducing postinjury and postoperative pain. Those patients who used marijuana during their recovery felt that it alleviated symptoms of pain and reduced their opioid intake. Our results help inform clinicians regarding the perceptions of patients with trauma regarding the usefulness of marijuana in treating pain and support further study into the utility of medical marijuana in this population.
A Prospective Randomized Study on Operative Treatment for Simple Distal Tibial Fractures—Minimally Invasive Plate Osteosynthesis Versus Minimal Open Reduction and Internal Fixation
Authors: Kim Ji Wan , Kim Hyun Uk , Oh Chang-Wug , Kim Joon-Woo , Park Ki Chul
Published: August 2017

Objectives:

To compare the radiologic and clinical results of minimally invasive plate osteosynthesis (MIPO) and minimal open reduction and internal fixation (ORIF) for simple distal tibial fractures.

Design:

Randomized prospective study.

Setting:

Three level 1 trauma centers.

Patients:

Fifty-eight patients with simple and distal tibial fractures were randomized into a MIPO group (treatment with MIPO; n = 29) or a minimal group (treatment with minimal ORIF; n = 29). These numbers were designed to define the rate of soft tissue complication; therefore, validation of superiority in union time or determination of differences in rates of delayed union was limited in this study.

Intervention:

Simple distal tibial fractures treated with MIPO or minimal ORIF.

Main Outcome Measurements:

The clinical outcome measurements included operative time, radiation exposure time, and soft tissue complications. To evaluate a patient's function, the American Orthopedic Foot and Ankle Society ankle score (AOFAS) was used. Radiologic measurements included fracture alignment, delayed union, and union time.

Results:

All patients acquired bone union without any secondary intervention. The mean union time was 17.4 weeks and 16.3 weeks in the MIPO and minimal groups, respectively. There was 1 case of delayed union and 1 case of superficial infection in each group. The radiation exposure time was shorter in the minimal group than in the MIPO group. Coronal angulation showed a difference between both groups. The American Orthopedic Foot and Ankle Society ankle scores were 86.0 and 86.7 in the MIPO and minimal groups, respectively. Minimal ORIF resulted in similar outcomes, with no increased rate of soft tissue problems compared to MIPO.

Conclusions:

Both MIPO and minimal ORIF have high union rates and good functional outcomes for simple distal tibial fractures. Minimal ORIF did not result in increased rates of infection and wound dehiscence.

Level of Evidence:

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.
Ewing Sarcoma of the Spine
Authors: Charest-Morin Raphaële , Dirks Michael S. , Patel Shreyaskumar , Boriani Stefano , Luzzati Alessandro , Fehlings Michael G. , Fisher Charles G. , Dekutoski Mark B. , Williams Richard , Quraishi Nasir A. , Gokaslan Ziya L. , Bettegowda Chetan , Germscheid Niccole M. , Varga Peter P. , Rhines Laurence D.
Published: August 2017

Study Design.

Multicenter, ambispective observational study.

Objective.

To quantify mortality and local recurrence after surgical treatment of spinal Ewing sarcoma (ES) and to determine whether an Enneking appropriate procedure and surgical margins (en bloc resection with wide/marginal margins) are associated with improved prognosis.

Summary of Background Data.

Treatment of primary ES of the spine is complex. Ambiguity remains regarding the role and optimal type of surgery in the treatment of spinal ES.

Methods.

The AOSpine Knowledge Forum Tumor developed a multicenter database including demographics, diagnosis, treatment, mortality, and recurrence rate data for spinal ES. Patients were stratified based on surgical margins and Enneking appropriateness. Survival and recurrence were analyzed using Kaplan-Meier curves and log-rank tests.

Results.

Fifty-eight patients diagnosed with primary spinal ES underwent surgery. Enneking appropriateness of surgery was known for 55 patients; 24 (44%) treated Enneking appropriately (EA) and 31 (56%) treated Enneking inappropriately (EI). A statistically significant difference in favor of EA-treated patients was found with regards to survival (P = 0.034). Neoadjuvant and postoperative chemotherapy was significantly associated with increased survival (P = 0.008). Local recurrence occurred in 22% (N = 5) of patients with an EA procedure versus 38% (N = 11) of patients with an EI procedure. The timing of chemotherapy treatment was significantly different between the Enneking cohorts (P < 0.001) and all EA-treated patients received chemotherapy treatment. Although, local recurrence was not significantly different between Enneking cohorts (P = 0.140), intralesional surgical margins and patients who received a previous spine tumor operation were associated with increased local recurrence (P = 0.025 and P = 0.018, respectively).

Conclusion.

Surgery should be undertaken when an en bloc resection with wide/marginal margins is feasible. An EA surgery correlates with improved survival, but the impact of other prognostic factors needs to be evaluated. En bloc resection with wide/marginal margins is associated with local control.

Level of Evidence: 3
Hyperbaric Oxygen Therapy After Acute Thoracic Spinal Cord Injury
Authors: Falavigna Asdrubal , Figueiró Manuela Peletti , Silva Pedro Guarise da , Conzatti Lucas Piccoli , Rizkalla Elisa Braun , Santos Scheila Cardoso dos , Quadros Francine Würzius de , Radaelli Lucas
Published: August 2017

Study Design.

A controlled laboratory study.

Objective.

The aim of this study was to analyze the effectiveness of hyperbaric therapy (HT) using mild and moderate models of spinal cord injury (SCI).

Summary of Background Data.

SCI can cause permanent impairment with socioeconomic consequences. The motor deficit occurs by two mechanisms: destruction of neuronal cells and local inflammatory response, resulting in hypoxia. HT acts by increasing oxygen in the injured area.

Methods.

Thoracic laminectomy was performed in 72 female Wistar rats. The MASCIS impactor was used at 12.5 mm (n = 35) and 25 mm (n = 35) of height to perform, respectively, mild and moderate SCI. Muscle strength was assessed through the Basso, Beattie, and Bresnahan scale (BBB) on days 1, 7, 14, 21, and 28 after SCI. The animals were randomized into five subgroups with seven animals each: (1) control group had SCI without HT; (2) HT 30 minutes after SCI; (3) HT 30 minutes after SCI and daily for 7 days; (4) HT 12 hours after SCI; and (5) HT 12 hours after SCI and daily for 7 days. HT was performed at 2.5 atm for 1 hour.

Results.

There was a linear relationship between injury severity and motor deficit until day 21, with similar BBB scores on day 28. A pattern of uniform lesions was observed in the mild SCI, with lower variation of BBB when compared with moderate SCI. All animals that underwent HT had significant improvement in motor function and histology when compared with control group. Regardless of the injury model, animals submitted to 7-day protocols had an early improvement in motor function and a smaller area of histological injury.

Conclusion.

The present study reported that the sooner HT is begun after mild and moderate SCI and the larger the number of sessions, the greater and earlier is the motor recovery and smaller is the tissue injury.

Level of Evidence: N/A
Getting PEEK to Stick to Bone: The Development of Porous PEEK for Interbody Fusion Devices
Authors: Torstrick F. Brennan , Safranski David L. , Burkus J. Kenneth , Chappuis James L. , Lee Christopher S.D. , Guldberg Robert E. , Gall Ken , Smith Kathryn E.
Published: August 2017

Interbody fusion cages are routinely implanted during spinal fusion procedures to facilitate arthrodesis of a degenerated or unstable vertebral segment. Current cages are most commonly made from polyether-ether-ketone (PEEK) due to its favorable mechanical properties and imaging characteristics. However, the smooth surface of current PEEK cages may limit implant osseointegration and may inhibit successful fusion. We present the development and clinical application of the first commercially available porous PEEK fusion cage (COHERE) ® that aims to enhance PEEK osseointegration and spinal fusion outcomes. The porous PEEK structure is extruded directly from the underlying solid and mimics the structural and mechanical properties of trabecular bone to support bone ingrowth and implant fixation. Biomechanical testing of the COHERE device has demonstrated greater expulsion resistance versus smooth PEEK cages with ridges and greater adhesion strength of porous PEEK versus plasma-sprayed titanium coated PEEK surfaces. In vitro experiments have shown favorable cell attachment to porous PEEK and greater proliferation and mineralization of cell cultures grown on porous PEEK versus smooth PEEK and smooth titanium surfaces, suggesting that the porous structure enhances bone formation at the cellular level. At the implant level, preclinical animal studies have found comparable bone ingrowth into porous PEEK as those previously reported for porous titanium, leading to twice the fixation strength of smooth PEEK implants. Finally, two clinical case studies are presented demonstrating the effectiveness of the COHERE device in cervical spinal fusion.