bluuebunny/crossref_metadata_2025 huggingface dataset:
Assisting the Elderly in Remaining Politically Active: A Focus on Russia and its International Legal Obligations
Authors: Riekkinen Mariya
Published: June 2011

This article focuses on the potential of the elderly as a distinct social group capable of changing the direction of state policies. As far as the elderly have special rights and, also, expectations that these rights will be protected, they are capable of generating their own political preferences. In effect, they can be identified as a special group empowered to take part in the conduct of public affairs. It is a known fact that the political views of citizens are formulated long before individuals come to vote at polling stations. The author will examine which opportunities are provided for the elderly by the Russian state, so that these people can freely discuss public policies and remain politically active for an extended period of time.

These issues are dealt with in the context of Russian international legal obligations. This study is based on the praxis of international treaty-monitoring bodies. Russian statutory law and its application by courts and administrative organs are also explored.
Portraits of jurists from the 'Ancient Netherlands'
Authors: Feenstra R.
Published: June 2011

Extensive review of a publication including 22 engravings of jurists from the Low Countries, taken from J.F. Foppens,Bibliotheca Belgica, Bruxellis 1739. The editors, T. Dankers and P. Delsaerdt, add short comments on their lives and works, with references to biographical sources. In the present review special attention is given to Matthaeus Wesenbecius and Franciscus Modius.
The Royal Decree E 100 'Herstel Rechtsverkeer' of 1944 and the post-war case law concerning real estate
Authors: Kop Peter
Published: June 2011

Extensive review of the doctoral dissertation of Kornelius Meijer on this subject which focuses on the jurisdiction of the (Dutch) Council for the restoration of rights, on the procedural and substantive law of E 100 and on the case law concerning real estate. Up to now questions arise as to the unique position of the Decree E 100 and to the capacity of J. Eggens as a legislator.
Seasonal dynamics and overwintering strategy of the tachinid fly (Diptera: Tachinidae), Ormia ochracea (Bigot) in southern California
Authors: Paur Jennifer , Gray David
Published: June 2011

We present the first data on the seasonal abundance of an acoustically orienting parasitoid fly, Ormia ochracea (Bigot), in southern California. Peak population abundance of the parasitoid lags peak population abundance of its primary local host species the field cricket Gryllus lineaticeps Stål, by about six weeks. We also examined pupal diapause as a potential overwintering mechanism. Taken together our results suggest (1) that O. ochracea lacks a highly effective pupal diapause, (2) that spring adult field cricket species are safe from the fly, and (3) that most of the late fall flies die without reproducing.
Maria Sibylla Merian (1647-1717): an early investigator of parasitoids and phenotypic plasticity
Authors: Todd Kim
Published: June 2011

In a time when science and technology were almost exclusively dominated by men, the European naturalist and biological illustrator, Maria Sibylla Merian (1647-1717), studied arthropods, particularly American and European insects. rough careful observations, she documented and lavishly depicted phenomena that today we call parasitoidism and phenotypic plasticity, making her one of the first to inquire into these topics. Merian's legacy emphasizes the inextricable link between the environment and organisms.
Ants as biological control agents in agricultural cropping systems
Authors: Drummond Frank , Choate Beth
Published: June 2011

Ants positively impact agricultural systems by rapidly consuming large numbers of pest insects, disturbing pests during feeding and oviposition, and increasing soil quality and nutrients. The ability of ants to control pest species has been recognized since the year 300 A.D. and farmers continue to conserve and promote ant populations in agricultural systems worldwide. Naturally occurring ant species in milpas, mango, citrus, coconut, cashews, and cotton control many pest insects. Through judicious insecticide application and changes in management practices such as tillage, and other manipulations of vegetation and crop structure, beneficial ant populations are conserved in a variety of agroecosystems. The first recorded example of biological control was the manipulation of ants throughout citrus orchards in Asia. Augmentation continues in citrus, and methods of ant introduction have been developed in Malaysian and Indonesian cocoa plantations, as well as to control sweet potato and banana weevils in Cuba. Ant species have been formally incorporated into other integrated pest management programs for cashew in Australia, cocoa in Papua New Guinea, and mango in Australia and Vietnam. With efforts to reduce chemical pesticide input in agricultural systems, research evaluating the ability of generalist ant species to control pest insects must continue.
UN Peacekeeping in the Democratic Republic of Congo: Reflections on MONUSCO and Its Contradictory Mandate
Authors: Clark Janine Natalya
Published: June 2011

Both because the United Nations (UN) spectacularly failed in Rwanda and because of the close links between the 1994 Rwandan genocide and the continuing conflict in the Democratic Republic of Congo (DRC), the United Nations Organization Stabilization Mission in the Democratic Republic of Congo (MONUSCO) – formerly the United Nations Organization Mission in the Democratic Republic of Congo (MONUC) – constitutes an important test-case for UN peacekeeping. However, since MONUSCO is ongoing, it is too early to assess whether or not it has passed this test. This article, however, focuses on a particular issue that may ultimately cause the mission to fail, namely contradictions within its ever-expanding mandate. It argues that MONUSCO itself is helping to fuel these tensions through its flawed approach to one of the key components of its mandate, namely DDR (disarmament, demobilization and reintegration) and DDRRR (disarmament, demobilization, repatriation, resettlement and reintegration). It thus suggests how MONUSCO might revise its approach to these processes, particularly through a more ‘bottom-up’ focus that engages directly with local communities and with former combatants as individuals.
Civil Jurisdiction and Religious Accord: Bruker v. Marcovitz in the Supreme Court of Canada
Authors: Baumel Joseph Norma
Published: June 2011

In 2007 the Supreme Court of Canada ruled on the case of Bruker v. Marcovitz with the majority position being delivered by Justice Abella. Although on one hand the case might appear simply as one of contract law in Quebec, this particular ruling had many ramifications in terms of freedom of religion and state—church interaction. The article addresses the particularities of Jewish divorce laws and the complexities entered into within a civil society. Questions of the separation of church and state and the interaction of two legal systems continue to cause conflict and debate in both Canada and the United States of America. The couple involved had many years of litigation, and had already been both civilly divorced and Jewishly divorced. The issue at hand was whether one party could sue the other party for breach of contract if the said contract involved a religious obligation. The debate intrigues scholars and community participants alike.
Jewish Communal Identity at the Crossroads: Early Jewish Responses to Canadian Multiculturalism, 1963-1965
Authors: Menkis Richard
Published: June 2011

This article challenges the assumption that the Canadian Jewish community embraced the discourse and potential of multiculturalism rapidly and enthusiastically. It has been proven that certain groups—most notably the Ukrainians—used the hearings of the Royal Commission on Bilingualism and Biculturalism, which promised to consider the ‘‘contributions of the other ethnic’’ groups, to promote the idea that Canada is multicultural. But the largest organization of Canadian Jewry—the Canadian Jewish Congress (CJC)—was very cautious in its dealings with the Commission. It only participated in the Preliminary Hearings, in order to protest the preamble’s language that referred to the ‘‘two founding races. From the records of meetings, it is evident that CJC, based in Montreal—which was the home of the largest Jewish community in Canada at the time—was worried that introducing ‘‘multiculturalism’’ would offend the French. This article also asserts that CJC was not willing to define the Jews as an ethnic group, which was the implied category for groups in the new discourse of multiculturalism. CJC thought that a self-definition of the Jews as an ethnic group would weaken the place of Jews in Canadian society, both because of how Jews defined themselves on the census of 1961 and because they believed that they had a higher profile in the division of society into Protestant—Catholic—Jew than in a society divided into ethnic groups.
Yom Hashoah , Jour commémoratif de l’Holocauste, dans le calendrier juif canadien
Authors: Bauer Julien
Published: June 2011

Le calendrier joue un rôle essentiel dans l’identité d’un groupe. Après la Seconde guerre mondiale, la question s’est posée si une date particulière devait commémorer les victimes de l’Holocauste. Les réponses ont varié selon les pays. Au Canada, une date particulière s’est imposée. D’une cérémonie limitée aux survivants et à leurs descendants, Yom Hashoah est, petit à petit, grâce à un certain nombre de changements dans son organisation, devenu un élément marquant, quasi unanimement reconnu par les Juifs du Canada.
‘‘The Other Side of the Coin’’: The Anatomy of a Public Controversy in the Montreal Jewish Community, 1931
Authors: Robinson Ira
Published: June 2011

This article examines in detail the repercussions of a 1931 sermon by Sheea Herschorn, an immigrant Orthodox rabbi in Montreal, on the public discourse of the Montreal Jewish community. It begins with a brief consideration of the position of the immigrant Orthodox rabbinate in Montreal and then explores the nature of the public discourse on this sermon, in which Rabbi Herschorn was accused of agreeing with an anti-Semitic position, through a close examination of the reportage of the controversy in Montreal’s Jewish press, which then included two newspapers in Yiddish, the Keneder Adler and Der Shtern, as well as the English-language Canadian Jewish Chronicle. Finally, the article explores some of the major issues raised in Rabbi Herschorn’s sermon regarding the contemporary situation of Polish Jews in relation to their society, tying it to his perception of the relationship of Canadian Jews and Canadian society as a whole. These latter issues included especially the relationship between Montreal Jews and Montreal’s public Anglophone institutions, such as the Royal Victoria Hospital, and McGill University, whose ambivalent acceptance of Jews as physicians and students was then an issue of great concern to the Jewish community.
‘‘The Problem of the Modern Orthodox Rabbinate’’: Montreal’s Vaad Harabbonim at Mid-Century
Authors: Lapidus Steven
Published: June 2011

The postwar years brought demographic expansion to Montreal’s Jewish community, including residential mobility into new neighbourhoods. These growing suburban Jewish communities engaged young, English-speaking and mostly American rabbis for their congregations. Not surprisingly, the arrival of several of these Modern Orthodox rabbis at mid-century was not unnoticed by the established, mostly eastern European, members of Montreal’s Rabbinical Council. Typically at this period, many European rabbis were sceptical of their American-trained colleagues’ authenticity, knowledge and capability. Montreal was no exception. Using archival documents, this article examines the tensions in mid-century Montreal between the rabbis of the Yiddish-speaking Vaad Harabbonim and the freshly-minted Modern Orthodox rabbis of the next generation.
International Review: Industrial Relations in Britain under New Labour, 1997-2010: A Post Mortem
Authors: Brown William
Published: June 2011

A revival of trade unions was widely expected when Blair’s New Labour government took over from the Conservatives in Britain in 1997. This did not occur and collective bargaining continued to retreat. This article discusses the implications of the changing economic context for the government’s legal innovations, notably, statutory trade union recognition and a minimum wage, and describes the consequences for industrial relations. It concludes that New Labour’s legacy may lie in its nurturing of the institutions of social partnership and the use of conciliation.
Major Tribunal Decisions in 2010
Authors: Catanzariti Joseph , Brown Simon
Published: June 2011

This article examines a number of Full Bench decisions from Fair Work Australia in 2010, in particular those relating to agreement-making and enterprise bargaining under the Fair Work Act 2009. Those decisions have shed further light on the operation of what remains relatively new legislation. With respect to agreement-making, the Full Bench has evinced an intention to take a practical and non-technical approach in determining whether the pre-approval requirements under s.180 of the Act have been met, and to afford employers an opportunity to address any concerns about approval of an agreement by way of undertakings. The Full Bench decisions examined in this article also demonstrate that Fair Work Australia will take a non-interventionist approach to enterprise bargaining and protected industrial action. Provided the parties are conducting themselves in accordance with the Fair Work Act, the tribunal will be loath to intervene in enterprise bargaining in a way that would alter the status quo or undermine the bargaining position of a party. The rationale for this approach is that, in the absence of any meaningful powers of compulsory arbitration under the Fair Work Act, enterprise bargaining is now the only means by which employees can collectively negotiate terms and conditions above the minima set down under modern awards and the National Employment Standards.
Industrial Relations in 2010: ‘Dead, Buried and Cremated’?
Authors: Cooper Rae
Published: June 2011

The process of embedding the Fair Work system was interrupted briefly in 2010 by high political drama. The Prime Minister, Kevin Rudd, was successfully challenged by his Deputy, the Minister for Employment and Workplace Relations, Julia Gillard. With its first female leader, the Australian Labor Party attempted to run a campaign echoing the anti-Work Choices theme of 2007. This was stymied by the new leader of the opposition Tony Abbott’s insistence that Work Choices was ‘dead, buried and cremated’. Subsequently, a minority Labor government was formed. This article provides an overview of industrial relations in 2010, with an emphasis on politics.
Practitioner Review: Enough Love to End the Struggle? A Union Reflection on Life under Fair Work and Portents for the Future
Authors: Lyons Tim
Published: June 2011

Although the initial signs are encouraging, it is too early to pass final judgement on the performance of the Fair Work system. Key aspects of the bargaining regime are likely to require amendment to take better account of the nature of Australia’s labour market and economy, in particular to facilitate easier access to multi-employer bargaining and to deal with contingent employment.
Employer and Employer Association Matters in 2010
Authors: Todd Patricia
Published: June 2011

In 2010 much of the activity in industrial relations for employers and employer associations was focused on transitioning to and complying with the Fair Work Act 2009. The issues identified by employer associations as being of most concern have varied. For many in the services sector, as well as in small businesses in other sectors, the focus has been on the impact of the modern awards; while in industries such as mining, construction and manufacturing, bargaining and agreement-making have been of a higher order of priority. There have been numerous other IR matters also occupying employers’ time, including the proposed amendments to the building industry inspectorate’s powers, which remain in ‘limbo’. Towards the end of the year, serious concerns about the supply of skilled labour arose again, which, together with the enhanced union bargaining capacity provided by the Fair Work Act, suggests that employers may expect more ‘hard bargaining’ in some sectors in 2011.
Observer-based robust motion control of a piezo-actuated stage under external disturbances
Authors: Sofla Mohammad Sheikh , Barazandeh Farshad , Rezaei Seyed Mehdi , Zareinejad Mohammad , Saadat Mozafar
Published: June 2011

Piezoelectric actuators (PEAs) are frequently used in a wide variety of micromanipulation systems. However, the hysteresis non-linearity and the creep reduce their fidelity and cause difficulties in the micromanipulation control procedure. Besides, variation of temperature and external loads could change the model parameters identified for the piezo actuator. In this paper, a robust feedforward–feedback controller is proposed for precise tracking control of PEAs, under external disturbances. A Bouc–Wen hysteresis model is integrated with a second-order linear dynamic, to represent the behaviour of a PEA. Based on the Bouc–Wen model, a hysteresis observer is developed to estimate the hysteresis non-linear effect. Then, for real-time compensation of the observer error and the thermal and external load disturbances, a sliding mode control (SMC) strategy with a perturbation estimation function is utilized. To verify the efficiency of the proposed method, a comparison between the proposed approach and a classical SMC is presented.
Have We Drawn the Wrong Conclusions About the Value of Care Pathways? Is a Cochrane Review Appropriate?
Authors: Vanhaecht Kris , Ovretveit John , Elliott Martin J. , Sermeus Walter , Ellershaw John , Panella Massimiliano
Published: June 2011

Care pathways are used increasingly worldwide to organize patient care. However, different views exist about their effectiveness. One of the reasons for this is that pathways are complex interventions. A recent Cochrane review was published which reported positive results, but although the Cochrane team performed excellent work with an enormous commitment, the conclusions may be inappropriate. To fully understand the potential and problems of care pathways, it is important to define (a) exactly what we are talking about (b) whether the study methods are appropriate, and (c) whether we can properly define the outcomes.
Revisiting the importance of cognition in information science
Authors: Budd John M.
Published: June 2011

For a considerable amount of time the field of information science has employed its own, as well as the knowledge bases and methods of other fields (with productive results). One field that has been appropriated from has been cognitive science. Cognitive science, however, has been in flux over the last few decades, with different conceptual frameworks assuming ascendance at various times. That dynamic implies that information science should pay close attention to what is occurring in cognitive science in order to investigate the most complex of challenges in information retrieval use, behaviour, and other phenomena. This paper includes a review of the frameworks of cognitive science and suggests that some of the most recent work in that field holds promise for development of thought and inquiry in information science. Understanding of the complex individual processes within human brains, the relationships among thinking communicators, and the relationship of brain and mind, is one of the areas where particular attention should be paid.
Text summarization using Latent Semantic Analysis
Authors: Ozsoy Makbule Gulcin , Alpaslan Ferda Nur , Cicekli Ilyas
Published: June 2011

Text summarization solves the problem of presenting the information needed by a user in a compact form. There are different approaches to creating well-formed summaries. One of the newest methods is the Latent Semantic Analysis (LSA). In this paper, different LSA-based summarization algorithms are explained, two of which are proposed by the authors of this paper. The algorithms are evaluated on Turkish and English documents, and their performances are compared using their ROUGE scores. One of our algorithms produces the best scores and both algorithms perform equally well on Turkish and English document sets.
Making ‘care’ accessible: Personal assistance for disabled people and the politics of language
Authors: Kelly Christine
Published: June 2011

Disability scholars and activists argue that ‘care’ is a complex form of oppression and reject it as a term and concept. I explore the possibility of salvaging care from its oppressive medical and charitable legacies through a discussion of personal assistance. While not arguing for a return to terming personal assistance ‘care’, I argue care can be made accessible in policies and discussions of attendant services and in more general discussions related to care. Like the built environment, care requires ‘retrofitting’ as in updating existing structures to fully include disability perspectives. This requires redefining care as a complex tension. Accessibility also evokes the sense of ‘at hand’; keeping care at hand in policy discussions allows us to consider transformative feminist conceptualizations of care and captures intricate relationships between attendants and disabled people, including people with intellectual disabilities. Most importantly, accessible versions of care always acknowledge the oppressive legacies and coercive potentials of care.
Effects of acute alcohol consumption on alcohol-related cognitive biases in light and heavy drinkers are task-dependent
Authors: Adams Sally , Ataya Alia F , Attwood Angela S , Munafò Marcus R
Published: June 2011

We investigated (1) the effects of alcohol on cognitive biases for alcohol-related cues, (2) the effects of drinking status on alcohol-related cognitive biases and (3) the similarity of any effects of alcohol across two measures of alcohol cognitive bias. Healthy, heavy and light social alcohol users ( n = 72) were examined in a single-blind placebo-controlled design. Participants received 0.00 g/kg, 0.13 g/kg or 0.40 g/kg of alcohol in a between-subjects design and then completed both a modified Stroop task and a visual probe task. Modified Stroop data indicated a main effect of cue type, which was qualified by drinking status, with heavier drinkers slower to respond to alcohol-related cues. Visual probe data, in contrast, indicated a significant interaction effect between validity (valid: alcohol-related, invalid: neutral) and drink condition. Participants receiving a moderate dose of alcohol (0.40 g/kg) were faster to respond to alcohol-related stimuli compared with participants receiving a low dose of alcohol or placebo. These data indicate that the cognitive processes assayed by the visual probe and Stroop tasks may not be mediated by a common underlying mechanism.
Musical activities predispose to involuntary musical imagery
Authors: Liikkanen Lassi A.
Published: June 2011

Involuntary semantic memories are a new topic in psychology. Initial research has suggested that musical memories are a dominant type of involuntary memory. Interestingly, no comprehensive information exists on the commonality of “earworms”, or repeated involuntary imagery of music (INMI), and its relationship to the engagement with musical activities. The present study investigated these using cross-sectional, retrospective reports from a questionnaire study that was conducted among Finnish internet users ( N = 12,519). The analyses of the data revealed that 89.2% of participants reported experiencing this phenomenon at least once a week. The amount of music practice and listening was positively related to the frequency of involuntary music. Women reported elevated levels of involuntary imagery episodes in contrast to men, who reacted differently. In older age-groups the frequency of the incidents decreased among both sexes. People with extensive musical practice history seemed to experience longer musical segments and more often instrumental ones. They were less agitated by involuntary music and reported it less often. The results are discussed in relation to a memory-based hypothesis of involuntary musical imagery. In conclusion, INMI is viewed as an integral part of our musical mind.
Fatigue microcrack detection with digital image correlation
Authors: Rupil J , Roux S , Hild F , Vincent L
Published: June 2011

A digital image correlation method is proposed to detect and quantify automatically microcracks on the surface of a specimen during a fatigue test. The proposed procedure allows for a fast scanning of the entire surface with all possible (pixel-wise) locations of microcrack centres and the detection of cracks having a sub-pixel opening. An experimental test case is presented as an illustration of the method and a comparison with a replica technique is performed.
Weld zone representation during the formability prediction of friction stir welded blanks with similar thickness sheets
Authors: Ramulu P J , Ganesh Narayanan R
Published: June 2011

During formability prediction of friction stir welded (FSW) blanks, it is necessary to incorporate nugget zone and heat-affected zone (HAZ) properties separately for better accuracy. In general, it is observed that the weld zone is represented as a single entity, in which only global weld zone properties are implemented. In this work, it is proposed that there is a domain of weld conditions in which the single-zone assumption (nugget and HAZ are modelled without incorporating their individual properties) breaks down and the double-zone assumption (nugget zone and HAZ are represented separately) should be followed. During limiting dome height simulations, a representative base material is considered from the literature with changing nugget zone and HAZ properties. The punch displacement at failure and maximum load are compared between FSW blanks modelled with single- and double-zone assumptions. It is observed that modelling FSW blanks with double-zone assumption plays a vital role for accurate formability prediction. The single-zone assumption is not valid for all the FSW conditions. Both in transverse and longitudinal weld orientations, there are possibilities of multiple domains in which the double-zone assumption is valid. It is found that there exists a relationship between the thickness distribution and availability of single-zone or double-zone models. Whenever the thickness distribution of a particular double zone is closer to the reference case modelled with single zone, it is sufficient to model that weld zone case with a single zone. Double-zone representation is required in cases when the thickness distribution is very different. The domains for weld zone modelling in FSW blanks are sensitive to failure location. Put simply, it is advisable to model HAZ separately, when failure occurs in it. But this is not always the case. It depends on a compromise between the accuracy and availability of HAZ properties.
An incremental formulation for half-plane contact problems subject to varying normal load, shear, and tension
Authors: Hills D A , Davies M , Barber J R
Published: June 2011

The classical Cauchy integral equation formulation used to solve contact problems capable of representation within a half-plane formulation for elastically similar materials, is developed so that the problem is reducible to an Abel equation for normal load. A fully-adhered solution is then developed permitting the interfacial shearing tractions induced by shear and a difference in remote tensions. This is applied to wedge, Hertz and flat and rounded contact problems, and the condtions for sustained adhesion found. The results found have general applicability, but are particularly relevant to the kind of load history experienced in a gas turbine blade root fixing.
Equivalent stress and strain distribution in helical compression springs subjected to bending
Authors: Keller S G , Gordon A P
Published: June 2011

Stress and strain analyses of helical compression springs have long been an important factor in machine design. Designs routinely incorporate helical springs, either tensile or compressive, to transmit uniaxial loads. Recently, multiaxial loading has become more commonplace, with devices such as flexible shaft couplings. Through static mechanical experiments, coupled with finite element analysis, the equivalent stress distribution in uniformly deformed springs is developed based solely upon visual inspection of the bent helix. Equivalent strains are also approximated, with satisfactory correlation between predicted and observed strains. In situations that involve space constraints, stress monitoring equipment may be intrusive; as such, approximations have been based solely on visual inspection of the deformed helix.
Concentration of shear stresses in shallow periodic notches
Authors: Dragoni E , Castagnetti D
Published: June 2011

The torsional stresses in straight round bars with periodic U-shaped shallow grooves are calculated numerically (boundary elements) taking advantage of a computationally efficient thermal analogy. Neuber’s theory is scrutinized, which equates the stress concentration factor in the periodic notch to the stress concentration factor in the single notch of like profile and lower depth. (Corrected depth = original depth times a depth reduction factor, which is a function of the depth-to-pitch aspect ratio of the periodic notch.) The results disclose a depth correction function in close agreement with Neuber’s theory for ideally sharp notches. For a wide range of rounded notches, which are more likely to occur in practice, the paper shows that Neuber’s depth correction grossly overestimates the stresses. By modifying the expression of the depth correction factor, however, Neuber’s conceptual equivalence works well for engineering purposes. Comparison with former results by the authors indicates that the optimal depth correction function is different for notches affected by shear stresses (as in this paper) or by normal stresses.
Effect of Acetabular Labrum Tears on Hip Stability and Labral Strain in a Joint Compression Model
Authors: Smith Matthew V. , Panchal Hemang B. , Ruberte Thiele Ramon A. , Sekiya Jon K.
Published: June 2011

Background

Acetabular labrum tears are now commonly diagnosed in young and active patients. Because the role of the acetabular labrum is incompletely understood, it is critical to determine how these tears affect native hip biomechanics.

Hypothesis

Radial and circumferential labral tears significantly decrease hip stability and significantly alter strain patterns in the anterior and anterior-superior acetabular labrum.

Study Design

Controlled laboratory study.

Methods

Twenty-two human cadaveric hips without evidence of degeneration or dysplasia were assigned to a circumferential tear (n = 11) and a radial tear (n = 11) group. The hips were tested in a neutral position with an average compressive force of 25 N. In the circumferential tear group, the labral states were intact; 1-, 2-, and 3-cm circumferential tears; a 3-cm partial labrectomy; and a full labrectomy. In the radial tear group, the labral states were intact; a radial tear; a 1-, 2-, and 3-cm partial labrectomy; and a full labrectomy. The effect of labral injury on the stability ratio (peak dislocation force/compressive loads) and labral strain in the anterior and anterior-superior labrum was analyzed using repeated-measures analysis of variance.

Results

There was no significant difference in stability ratio after circumferential tears 3 cm or less in size compared with the intact labral state. Strain in the anterior and anterior-superior labrum was either unchanged or increased after circumferential labral tear. There was no significant difference in stability ratio after a radial tear or a 1-cm partial labrectomy compared with the intact labral state. A 2-cm partial labrectomy significantly decreased the stability ratio. Anterior and anterior-superior labral strain significantly decreased after a radial tear.

Conclusion

Under the influence of joint compression in a neutral hip position, the acetabular labrum continues to resist femoral head dislocation despite detachment from the acetabular rim. A radial tear in the acetabular labrum decreases adjacent labral strain, but removal of 2 cm or more of the acetabular labrum is needed before hip stability decreases.

Clinical Relevance

The findings suggest that the acetabular labrum continues to function to resist femoral head translation despite chondral-labral separation and that labral preservation, particularly with larger tears, may be important for maintaining hip stability. Further studies are needed to determine the effect of partial labral excision on the stability ratio with the hip in provocative positions such as extension, external rotation, and abduction.
Outcomes after the Arthroscopic Treatment of Femoroacetabular Impingement in a Mixed Group of High-Level Athletes
Authors: Nho Shane J. , Magennis Erin M. , Singh Christopher K. , Kelly Bryan T.
Published: June 2011

Background

Femoroacetabular impingement has become more widely recognized in the athletic patient population. The purpose of the present study was to review the clinical outcome after arthroscopic treatment of femoroacetabular impingement in a mixed population of high-level athletes.

Hypothesis

Arthroscopic treatment of femoroacetabular impingement results in significant improvement in clinical outcome and a high rate of return to play.

Study Design

Case series; Level of evidence, 4.

Methods

High-level athletes who underwent arthroscopic treatment of femoroacetabular impingement (rim trimming, labral refixation or debridement, femoral osteochondroplasty) with a minimum of 1-year follow-up were retrospectively identified. All patients completed hip-specific outcome scores (Modified Harris Hip Score [MHHS] and Hip Outcome Score [HOS]) at baseline and most recent follow-up.

Results

Forty-seven patients with an average age of 22.8 ± 6.2 years met the study criteria with a mean follow-up of 27.0 ± 5.5 months. Thirty-three patients (70.2%) were available for follow-up. The level of competition was 27.7% varsity high school, 53.2% college, and 19.1% professional athletes. There were statistically significant improvements in the mean MHHS score (preoperative, 68.6 ± 12.8; postoperative, 88.5 ± 17.7; P = .002) as well as the HOS score (preoperative, 78.8 ± 11.3; postoperative, 91.4 ± 14.0; P = .03). There was a significant improvement in the alpha angle, with 76.4° ± 14.5° preoperatively and 51.4° ± 11.7° postoperatively (P = .0003). Seventy-nine percent of patients were able to return to play after hip arthroscopy at a mean of 9.4 ± 4.7 months (range, 4-26 months); of those patients, 92.3% were able to return to the same level of competition. At 2-year follow-up, 73% of patients were able to return to play.

Conclusion

Arthroscopic treatment of femoroacetabular impingement in a mixed group of high-level athletes may result in a significant improvement in hip functional outcome: 78% of athletes were able to return to play at 1 year and 73% of athletes were able to play at 2-year follow-up.
Epidemiology of Major League Baseball Injuries
Authors: Posner Matthew , Cameron Kenneth L. , Wolf Jennifer Moriatis , Belmont Philip J. , Owens Brett D.
Published: June 2011

Background

Little is known about the injury rates in Major League Baseball (MLB) players, as a formal injury surveillance system does not exist. The goal of this study was to characterize the epidemiology of MLB injuries over a 7-year period.

Hypothesis

Injuries in MLB would be common.

Study Design

Descriptive epidemiologic study.

Methods

The authors analyzed the MLB disabled list data from 2002 through 2008. Injuries were analyzed for differences between seasons, as well as during seasons on a monthly basis. The injuries were categorized by major anatomic zones and then further stratified based on injury type. Position-specific subanalyses for pitcher and position players were performed.

Results

From the 2002 season through the 2008 season, an average of 438.9 players per year were placed on the disabled list, for a rate of 3.61 per 1000 athlete-exposures. There was a significant 37% increase in injuries between 2005 and 2008. The highest injury rate during the season was during the month of April (5.73/1000 exposures) and the lowest in September (0.54/1000 exposures). No differences were noted in the injury rates between the National League and the American League (incidence rate ratio [IRR] = 1.06; 95% confidence interval [CI] = 0.98, 1.15). Pitchers experienced 34% higher incidence rates for injury compared with fielders during the study period (IRR = 1.34; 95% CI = 1.25, 1.44). Among all player injuries, upper extremity injuries accounted for 51.4% while lower extremity injuries accounted for 30.6%. Injuries to the spine and core musculature accounted for 11.7% while other injuries and illnesses were 6.3% of the total disabled list entries. There was a significant association between position played and anatomic region injured ( P < .001), with pitchers experiencing a significantly greater proportion of injuries to the upper extremity (67.0%; 95% CI = 63.1%, 70.9%) compared with fielders (32.1%; 95% CI = 29.1%, 35.1%). Conversely, fielders experienced a significantly greater proportion of injuries to the lower extremity (47.5%; 95% CI = 43.8%, 51.1%) compared with pitchers (16.9%; 95% CI = 14.9%, 18.8%). The mean number of days on the disabled list was 56.6. Overall, a greater proportion of disability days were experienced by pitchers (62.4%; 95% CI = 62.0%, 62.8%; P < .001) compared with fielders (37.6%; 95% CI = 37.3%, 37.9%).

Conclusion

Injuries in MLB resulting in disabled list designation are common. Upper extremity injuries were predominant in pitchers, while lower extremity injuries are more common in position players. These data may be used in the development of a formal MLB injury database, as well as in the development and implementation of specific preseason training and in-season conditioning for injury prevention.
Defining a Safety Margin for Labral Suture Anchor Insertion Using the Acetabular Rim Angle
Authors: Lertwanich Pisit , Ejnisman Leandro , Torry Michael R. , Giphart J. Erik , Philippon Marc J.
Published: June 2011

Background

Suture anchors are commonly used to reattach a torn labrum to the acetabular rim. The acetabular rim anatomy is not uniform, and the safety margin for inserting suture anchors is unknown. The acetabular rim angle is an anatomic measurement that is indicative of the safety margin for inserting suture anchors.

Purpose

To investigate the acetabular rim angle as a function of clock position, to evaluate the effect of drill depth on the acetabular rim angle, and to evaluate the effect of rim trimming on the acetabular rim angle.

Study Design

Descriptive laboratory study.

Methods

Three-dimensional acetabular models were reconstructed from computed tomography scans of 20 nonpaired cadaveric hip specimens, and the acetabular rim angle, which quantifies the angle between the subchondral margin and the outer cortex of the acetabulum, was measured from the 8- to 4-o'clock positions. At each position, the acetabular rim angle was measured for 5 drill depths (10, 12.5, 15, 20, and 25 mm) to simulate different lengths of suture anchors or drill bit depths on the acetabular rim angle. To simulate rim trimming, the acetabular rim angle was measured at the points that would become the suture anchor insertion points after 2.5- and 5-mm rim trimming.

Results

Clock position, drill depth, and rim trimming all had significant effects on the acetabular rim angle (P < .0001). The acetabular rim angle was largest at the 2-o'clock and smallest at the 3-o'clock position. Greater drill depths provided smaller acetabular rim angles, whereas rim trimming provided larger acetabular rim angles.

Conclusion

The acetabular rim angle varied significantly as a function of the location on the acetabular rim. A shorter drill depth and a greater amount of rim trimming provided a larger acetabular rim angle.

Clinical Relevance

Surgeons should be aware of the acetabular rim variations, especially in the anterosuperior quadrant, as well as the effects of drill depth and rim trimming, when selecting the optimal insertion angle for suture anchor placement to avoid articular cartilage penetration. The acetabular safety angle was smallest at the 3-o'clock position. Therefore, extra care must be taken when drilling or inserting anchors around the 3-o'clock position.
Efficacy of Hip Arthroscopy in the Management of Synovial Chondromatosis
Authors: Marchie Anthony , Panuncialman Ian , McCarthy Joseph C.
Published: June 2011

Background

Synovial chondromatosis can result in intra-articular loose bodies. Open arthrotomy has been the conventional treatment for this condition in the hip. Hip arthroscopy, however, is a minimally invasive approach and avoids potential problems with open arthrotomy.

Purpose

This series was described to evaluate the role of arthroscopy in treatment and outcome of synovial chondromatosis of the hip at early to intermediate follow-up.

Study Design

Case series; Level of evidence, 4.

Methods

Twenty-nine patients had arthroscopic treatment for synovial chondromatosis of the hip. All loose bodies were intracapsular and smaller than 10 mm. Radiographs of the painful hip, computed tomography (CT), and gadolinium-enhanced magnetic resonance imaging (MRI) were obtained preoperatively. Intraoperatively, loose bodies were removed, and partial synovectomy, partial labrectomy, chondroplasty, and microfracture were done as needed.

Results

There were 14 women and 15 men (mean age, 41 years; mean duration of symptoms, 52 months). All patients had hip pain and 63% reported mechanical hip symptoms. Twenty-three patients were followed for at least 12 months (mean, 64 months). Loose bodies could be seen in the imaging studies of 52% of patients: 8 on radiographs and 7 with CT or gadolinium-enhanced MRI. At surgery, 23 of the 29 (79%) patients had torn labra and femoral head changes. There were an average of 35 loose bodies per patient. Twenty-five of the 29 (86%) had acetabular chondral findings. Five of the 29 patients (17%) eventually underwent total hip reconstruction surgery at a mean of 52 months; 5 of these patients had grade III/IV lesions at the time of arthroscopy. Eleven of the 23 patients (48%) had good to excellent outcomes at an average of 60 months. Recurrent symptoms were seen in 7 patients, and revision arthroscopy was done for 1 patient at 1-year follow-up, 2 patients at 4 years, 1 at 5 years, and 1 at 7-year follow-up. Complications included transient perineal and pedal paresthesia in 2 patients.

Conclusion

Patients with synovial chondromatosis with hip central compartment loose bodies that were less than 10 mm benefited from hip arthroscopy. Imaging studies alone failed to establish the diagnosis in 14 of 29 patients (48%). Diagnosis was made by direct visualization via arthroscopy. For patients with grade I/II cartilage change, early diagnosis and treatment via arthroscopy helped. It is a valid and effective treatment at early to intermediate follow-up.
Vascular Safe Zones in Hip Arthroscopy
Authors: McCormick Frank , Kleweno Conor P. , Jo Kim Young , Martin Scott D.
Published: June 2011

Background

Hip arthroscopy is an evolving surgical technique being performed in greater numbers because of advances in skill, improved technology, and increased demand. Identifying vascular safe zones using anatomic and intracapsular landmarks provides a valuable intraoperative guide to reduce the risk of damage to the femoral head blood supply during femoral neck osteoplasty and psoas tendon release.

Purpose

This series is presented to identify vascular safe zones for use in hip arthroscopy.

Study Design

Case series; Level of evidence, 4.

Methods

The authors analyzed 76 consecutive contrast-enhanced magnetic resonance scans obtained from patients with diagnosed femoral acetabular impingement. High-resolution 3-dimensional images were reconstructed to visualize the vasculature. The medial femoral circumflex artery (MFCA) course was traced from the anterior thigh to the femoral head. Specific attention was paid to its proximity to the psoas tendon at the site of release and the retinacular vessel course in relation to the femoral neck using a clock-face orientation.

Results

The MFCA was found inserting on the posterior superior femoral neck from the 10:30 to 12-o'clock position on the femoral neck shaft, just posterior to the lateral synovial fold, and progressed on the femoral neck via an average of 4 retinacular vessels (range, 2-6). Ninety-seven percent of vessels were posterior to the 12-o'clock position. The MFCA passes posteriorly a mean distance of 50% ± 8% between the lesser trochanter and inferior femoral head/acetabular junction, located a mean 15 ± 0.37 mm medial to the medial cortex of the femoral neck. The MFCA was within the middle third zone in 100% of the measurements.

Conclusion

The authors defined the following 2 safe zones: the femoral neck osteoplasty safe zone is on the anterior half of the femoral neck; the psoas tendon release safe zone is astride the middle third of the medial hip capsule (bordered by the lesser trochanter and inferior femoral head/acetabular junction).
Surgical Treatment of Femoroacetabular Impingement Improves Hip Kinematics
Authors: Bedi Asheesh , Dolan Mark , Hetsroni Iftach , Magennis Erin , Lipman Joseph , Buly Robert , Kelly Bryan T.
Published: June 2011

Background

Femoroacetabular impingement (FAI) is now recognized as the most common cause of early osteoarthritis in the nondysplastic hip. While the surgical treatment of FAI has demonstrated favorable clinical outcomes, the ability of an osteoplasty to reliably improve hip kinematics and range of motion remains unknown.

Purpose

This study used computer-assisted 3-dimensional (3D) analysis to assess differences in hip range of motion before and after the arthroscopic surgical treatment of symptomatic FAI.

Study Design

Case series; Level of evidence, 4.

Methods

Ten patients with symptomatic, focal cam and/or pincer impingement lesions underwent high-resolution computed tomography scans and computer-assisted 3D modeling of the involved hip before and after corrective arthroscopic surgery by the senior author. Cam location, alpha angle, neck-shaft angle, femoral version, and acetabular version at 12-o'clock through 3-o'clock positions were measured. The model was subsequently dynamized to define the preoperative and postoperative range of motion and location of impingement with hip flexion, internal rotation, and internal rotation at 90° of hip flexion. Statistical analysis of preoperative and postoperative hip flexion and internal rotation at 90° of hip flexion was performed using paired t tests with P < .05 defined as significant.

Results

The cam lesion was located between 12 o'clock and 5 o'clock in all cases. Mean preoperative alpha angle was 59.8° (range, 36°-76°). Mean femoral version was 12.5° (range, −15° to 32°). Mean preoperative hip flexion was 107.40° ± 11.6°, and mean internal rotation at 90° of hip flexion was 19.10° ± 13.0°. The location of impingement was unique in each case and not predictable based on simple radiographic measures (ie, alpha angle) alone. Corrective femoral and rim osteoplasty resulted in significant improvements in both hip flexion (3.8°; P = .002) and internal rotation (9.3°; P = .0002). Mean postoperative alpha angle was 36.4° (range, 22°-46°).

Conclusion

Focal cam and/or rim osteoplasty can reliably improve hip kinematics and range of motion in patients with symptomatic FAI, particularly the limitation of internal rotation in a flexed position. Computed tomography–based computer modeling can localize regions of anticipated mechanical impingement in symptomatic patients. A complete osteoplasty in these defined regions, through an arthroscopic or open approach, predictably improves range of motion and may help to eliminate the recurrent mechanical collision and secondary chondral injury associated with FAI.