bluuebunny/crossref_metadata_2025 huggingface dataset:
Lifetime Risk for Development of Atrial Fibrillation
Authors: Lloyd-Jones Donald M. , Wang Thomas J. , Leip Eric P. , Larson Martin G. , Levy Daniel , Vasan Ramachandran S. , D’Agostino Ralph B. , Massaro Joseph M. , Beiser Alexa , Wolf Philip A. , Benjamin Emelia J.
Published: August 2004

Background—

Atrial fibrillation (AF) is the most common cardiac dysrhythmia and a source of considerable morbidity and mortality, but lifetime risk for AF has not been estimated.

Methods and Results—

We included all participants in the Framingham Heart Study who were free of AF at index ages of 40 years and older. We estimated lifetime risks for AF (including atrial flutter) to age 95 years, with death free of AF as a competing event. We followed 3999 men and 4726 women from 1968 to 1999 (176 166 person-years); 936 participants had development of AF and 2621 died without prior AF. At age 40 years, lifetime risks for AF were 26.0% (95% CI, 24.0% to 27.0%) for men and 23.0% (21.0% to 24.0%) for women. Lifetime risks did not change substantially with increasing index age despite decreasing remaining years of life because AF incidence rose rapidly with advancing age. At age 80 years, lifetime risks for AF were 22.7% (20.1% to 24.1%) in men and 21.6% (19.3% to 22.7%) in women. In further analyses, counting only those who had development of AF without prior or concurrent congestive heart failure or myocardial infarction, lifetime risks for AF were approximately 16%.

Conclusions—

Lifetime risks for development of AF are 1 in 4 for men and women 40 years of age and older. Lifetime risks for AF are high (1 in 6), even in the absence of antecedent congestive heart failure or myocardial infarction. These substantial lifetime risks underscore the major public health burden posed by AF and the need for further investigation into predisposing conditions, preventive strategies, and more effective therapies.
Benefits and Risks of the Combination of Clopidogrel and Aspirin in Patients Undergoing Surgical Revascularization for Non–ST-Elevation Acute Coronary Syndrome
Authors: Fox Keith A.A. , Mehta Shamir R. , Peters Ron , Zhao Feng , Lakkis Nasser , Gersh Bernard J. , Yusuf Salim
Published: August 2004

Background—

Antiplatelet therapy and antithrombin therapy have been demonstrated to reduce the risk of cardiac events in patients presenting with acute coronary syndrome, yet all effective therapies also increase the risk of bleeding.

Methods and Results—

In the Clopidogrel in Unstable angina to prevent Recurrent ischemic Events (CURE) trial, 12 562 patients were randomized to clopidogrel or placebo in addition to aspirin, and the primary outcome was cardiovascular (CV) death, myocardial infarction (MI), or stroke. The benefits were consistent among those undergoing percutaneous coronary intervention (PCI) [9.6% for clopidogrel, 13.2% for placebo; relative risk (RR), 0.72; 95% CI, 0.57 to 0.90], coronary artery bypass grafting (CABG) surgery (14.5% for clopidogrel 16.2% for placebo; RR, 0.89; 95% CI, 0.71 to 1.11), and medical therapy only (8.1% for clopidogrel, 10.0% for placebo; RR, 0.80; 95% CI, 0.69 to 0.92; test for interaction among strata, 0.53). For CABG during the initial hospitalization (530 for placebo, 485 for clopidogrel), the frequency of CV death, MI or stroke before CABG was 4.7% for placebo and 2.9% for clopidogrel (RR, 0.56; 95% CI, 0.29 to 1.08). For the entire study, there was a 1% excess of major bleeding but no significant excess of life-threatening bleeding. Among patients undergoing CABG, the rates of life-threatening bleeding were 5.6% for clopidogrel and 4.2% for placebo (RR, 1.30; 95% CI, 0.91 to 1.95; both nonsignificant).

Conclusions—

The benefits versus risks of early and long-term clopidogrel therapy (freedom from CV death, MI, stroke, or life-threatening bleeding) are similar in those undergoing revascularization (CABG or PCI) and in the study population as a whole. Overall, the benefits of starting clopidogrel on admission appear to outweigh the risks, even among those who proceed to CABG during the initial hospitalization.
Loss of Collagen XVIII Enhances Neovascularization and Vascular Permeability in Atherosclerosis
Authors: Moulton Karen S. , Olsen Bjorn R. , Sonn Silvia , Fukai Naomi , Zurakowski David , Zeng Xiaokun
Published: August 2004

Background—

Plaque neovascularization is thought to promote atherosclerosis; however, the mechanisms of its regulation are not understood. Collagen XVIII and its proteolytically released endostatin fragment are abundant proteoglycans in vascular basement membranes and the walls of major blood vessels. We hypothesized that collagen XVIII in the aortic wall inhibits the proliferation and intimal extension of vasa vasorum.

Methods and Results—

To test our hypothesis, we bred collagen XVIII-knockout (
Col18a1
−/−
) mice into the atherosclerosis-prone apolipoprotein E-deficient (
ApoE
−/−
) strain. After 6 months on a cholesterol diet, aortas from
ApoE
−/−
;
Col18a1
−/−
and
ApoE
−/−
;
Col18a1
+/−
heterozygote mice showed increased atheroma coverage and enhanced lipid accumulation compared with wild-type littermates. We observed more extensive vasa vasorum and intimal neovascularization in knockout but not heterozygote aortas. Endothelial cells sprouting from
Col18a1
−/−
aortas were increased compared with heterozygote and wild-type aortas. In contrast, vascular permeability of large and small blood vessels was enhanced with even heterozygous loss of collagen XVIII but was not suppressed by increasing serum endostatin to wild-type levels.

Conclusions—

Our results identify a previously unrecognized function for collagen XVIII that maintains vascular permeability. Loss of this basement membrane proteoglycan enhances angiogenesis and vascular permeability during atherosclerosis by distinct gene-dose-dependent mechanisms.
Prevalent Low-Frequency Oscillation of Heart Rate
Authors: Wichterle Dan , Simek Jan , La Rovere Maria Teresa , Schwartz Peter J. , Camm A. John , Malik Marek
Published: August 2004

Background—

This study evaluates a novel method for postinfarction risk stratification based on frequency-domain characteristics of heart rate variability (HRV) in 24-hour Holter recordings.

Methods and Results—

A new risk predictor, prevalent low-frequency oscillation (PLF), was determined in the placebo population of the European Myocardial Infarction Amiodarone Trial (EMIAT). Frequencies of peaks detected in 5-minute low-frequency HRV spectra were averaged to obtain the PLF index. PLF ≥0.1 Hz was the strongest univariate predictor of all-cause mortality associated with relative risk of 6.4 (95% CI, 3.9 to 10.6;
P
<10
−12
). In a multivariate Cox’s regression model including clinical risk factors, mean RR interval, HRV index, low- and high-frequency HRV spectral power, and heart rate turbulence, PLF was the most powerful mortality predictor, with a relative risk of 4.6 (95% CI, 2.2 to 9.3;
P
=0.00003). Predictive power of PLF was blindly validated in the population of the Autonomic Tone and Reflexes After Myocardial Infarction (ATRAMI) trial. PLF ≥0.1 Hz was associated with univariate relative risk of 6.1 (95% CI, 2.9 to 12.9;
P
<10
−5
) for cardiac mortality or resuscitated cardiac arrest. In multivariate Cox’s regression model including age, left ventricular ejection fraction, baroreflex sensitivity, mean RR interval, standard deviation of normal RR intervals, low- and high-frequency HRV spectral power, and heart rate turbulence, only left ventricular ejection fraction and PLF were significant predictors, with relative risks of 4.2 (95% CI, 1.5 to 11.7;
P
=0.007) and 3.6 (95% CI, 1.3 to 10.5;
P
=0.02), respectively.

Conclusions—

An innovative analysis of frequency-domain HRV, which characterizes the distribution of spectral power within the low-frequency band, is a potent and independent risk stratifier in postinfarction patients.
Leptin Induces Hypertrophy via Endothelin-1–Reactive Oxygen Species Pathway in Cultured Neonatal Rat Cardiomyocytes
Authors: Xu Fang-Ping , Chen Min-Sheng , Wang Yan-Zhen , Yi Quan , Lin Shu-Bing , Chen Alex F. , Luo Jian-Dong
Published: August 2004

Background—

Obesity is a major risk factor for the development of cardiovascular disease. Emerging evidence indicates that leptin, a protein encoded by the obesity gene, is linked with cardiac hypertrophy in obese humans and directly induces cardiomyocyte hypertrophy in vitro. However, the mechanisms by which leptin induces cardiomyocyte hypertrophy are poorly understood.

Methods and Results—

This study investigated how leptin contributes to cardiomyocyte hypertrophy. Cultured neonatal rat cardiomyocytes were used to evaluate the effects of leptin on hypertrophy. Both endothelin-1 (ET-1) and reactive oxygen species (ROS) levels were elevated in a concentration-dependent manner in cardiomyocytes treated with leptin for 4 hours compared with those cells without leptin treatment. ET-1 stimulated ROS production in a concentration-dependent manner in cardiomyocytes. The augmentation of ROS levels in cardiomyocytes treated with both leptin and ET-1 was reversed by a selective ET
A
receptor antagonist, ABT-627, and catalase, a hydrogen peroxide–decomposing enzyme. After treatment for 72 hours, leptin or ET-1 concentration-dependently increased total RNA levels, cell surface areas, and protein synthesis in cardiomyocytes, all of which were significantly inhibited by ABT-627 or catalase treatment.

Conclusions—

These findings indicate that leptin elevates ET-1 and ROS levels, resulting in hypertrophy of cultured neonatal rat cardiac myocytes. The ET-1–ET
A
–ROS pathway may be involved in cardiomyocyte hypertrophy induced by leptin. ET
A
receptor antagonists and antioxidant therapy may provide an effective means of ameliorating cardiac dysfunction in obese humans.
Atrial Fibrillation Is Associated With Increased Spontaneous Calcium Release From the Sarcoplasmic Reticulum in Human Atrial Myocytes
Authors: Hove-Madsen Leif , Llach Anna , Bayes-Genís Antoni , Roura Santiago , Font Enrique Rodriguez , Arís Alejandro , Cinca Juan
Published: August 2004

Background—

Spontaneous Ca
2+
release from the sarcoplasmic reticulum (SR) can generate afterdepolarizations, and these have the potential to initiate arrhythmias. Therefore, an association may exist between spontaneous SR Ca
2+
release and initiation of atrial fibrillation (AF), but this has not yet been reported.

Methods and Results—

Spontaneous Ca
2+
release from the SR, manifested as Ca
2+
sparks and Ca
2+
waves, was recorded with confocal microscopy in atrial myocytes isolated from patients with and those without AF. In addition, the spontaneous inward current associated with Ca
2+
waves was measured with the use of the perforated patch-clamp technique. The Ca
2+
spark frequency was higher in 8 patients with AF than in 16 patients without (6.0±1.2 versus 2.8±0.8 sparks/mm per second,
P
<0.05). Similarly, the spontaneous Ca
2+
wave frequency was greater in patients with AF (2.8±0.5 versus 1.1±0.3 waves/mm per second,
P
<0.01). The spontaneous inward current frequency was also higher in 10 patients with AF than in 13 patients without this arrhythmia (0.101±0.028 versus 0.031±0.007 per second,
P
<0.05, at a clamped potential of −80 mV). In contrast, both the Ca
2+
released from the SR and the Na
+
-Ca
2+
exchange rate induced by a rapid caffeine application were comparable in patients with and without AF.

Conclusions—

The observed increase in spontaneous Ca
2+
release in patients with AF probably is due to an upregulation of the SR Ca
2+
release channel activity, which may contribute to the development of AF.
Randomized, Controlled Evaluation of Short- and Long-Term Benefits of Heart Failure Disease Management Within a Diverse Provider Network
Authors: Kimmelstiel Carey , Levine Daniel , Perry Kathleen , Patel Ayan R. , Sadaniantz Ara , Gorham Noreen , Cunnie Margaret , Duggan Lynne , Cotter Linda , Shea-Albright Patricia , Poppas Athena , LaBresh Kenneth , Forman Daniel , Brill David , Rand William , Gregory Douglas , Udelson James E. , Lorell Beverly , Konstam Varda , Furlong Kathleen , Konstam Marvin A.
Published: August 2004

Background—

Several trials support the usefulness of disease management (DM) for improving clinical outcomes in heart failure (HF). Most of these studies are limited by small sample size; absence of concurrent, randomized controls; limited follow-up; restriction to urban academic centers; and low baseline use of effective medications.

Methods and Results—

We performed a prospective, randomized assessment of the effectiveness of HF DM delivered for 90 days across a diverse provider network in a heterogeneous population of 200 patients with high baseline use of approved HF pharmacotherapy. During a 90-day follow-up, patients randomized to DM experienced fewer hospitalizations for HF [primary end point, 0.55±0.15 per patient-year alive versus 1.14±0.22 per patient-year alive in control subjects; relative risk (RR), 0.48,
P
=0.027]. Intervention patients experienced reductions in hospital days related to a primary diagnosis of HF (4.3±0.4 versus 7.8±0.6 days hospitalized per patient-year; RR, 0.54;
P
<0.001), cardiovascular hospitalizations (0.81±0.19 versus 1.43±0.24 per patient-year alive; RR, 0.57;
P
=0.043), and days in hospital per patient-year alive for cardiovascular cause (RR, 0.64;
P
<0.001). Intervention patients showed a trend toward reduced all-cause hospitalizations and total hospital days. On long-term (mean, 283 days) follow-up, there was substantial attrition of the 3-month gain in outcomes, with sustained significant reduction only in days in hospital for cardiac cause.

Conclusions—

In a population with high background use of standard HF therapy, a DM intervention, uniformly delivered across varied clinical sites, produced significant short-term improvement in HF-related clinical outcomes. Longer-term benefit likely requires more active chronic intervention, even among patients who appear clinically stable.
Platelet Function Predicts Myocardial Damage in Patients With Acute Myocardial Infarction
Authors: Frossard Martin , Fuchs Ingrid , Leitner Judith M. , Hsieh Kety , Vlcek Marianne , Losert Heidrun , Domanovits Hans , Schreiber Wolfgang , Laggner Anton N. , Jilma Bernd
Published: August 2004

Background—

Platelet activation is a hallmark of acute coronary syndromes. Numerous lines of evidence suggest a mechanistic link between von Willebrand factor or platelet hyperfunction and myocardial damage in patients with acute coronary syndromes. Thus, we assessed whether platelet function under high shear rates (collagen adenosine diphosphate closure times [CADP-CTs]) measured with the platelet function analyzer (PFA-100) may be enhanced in patients with myocardial infarction (MI) and whether it may predict the extent of myocardial damage as measured by creatine kinase (CK-MB) or troponin T (TnT) levels.

Methods and Results—

Patients with acute chest pain or symptoms suggestive of acute coronary syndromes (n=216) were prospectively examined at an emergency department. CADP-CT was significantly shorter in patients with MI, particularly in those with an ST-segment-elevation MI (STEMI) compared with the other patient groups (unstable angina, stable coronary artery disease, or controls). Furthermore, CADP-CT and collagen epinephrine–CT at presentation were independent predictors of myocardial damage as measured by CK-MB or TnT. Patients with MI whose CADP-CT values fell in the first quartile had 3-fold higher CK-MB and TnT levels than those in the fourth quartile.

Conclusions—

Patients with STEMI have significantly enhanced platelet function when measured under high shear rates. CADP-CT is an independent predictor of the severity of MI, as measured by markers of cardiac necrosis. Measurement of platelet function with the PFA-100 may help in the risk stratification of patients presenting with MI.
Surgery for Aneurysms of the Aortic Root
Authors: Zehr Kenton J. , Orszulak Thomas A. , Mullany Charles J. , Matloobi Alireza , Daly Richard C. , Dearani Joseph A. , Sundt Thoralf M. , Puga Francisco J. , Danielson Gordon K. , Schaff Hartzell V.
Published: August 2004

Background—

This study evaluated long-term results of aortic root replacement and valve-preserving aortic root reconstruction for patients with aneurysms involving the aortic root.

Methods and Results—

Two-hundred three patients aged 53±16 years (mean±SD; 153 male, 50 female) underwent elective or urgent aortic root surgery from 1971 to 2000 for an aortic root aneurysm: 149 patients underwent a composite valve conduit reconstruction, and 54 patients underwent valve-preserving aortic root reconstruction. Fifty patients had Marfan syndrome. In-hospital and 30-day mortality was 4.0% (8/203) overall: for a composite valve conduit procedure, the corresponding value was 4.0% (6/149) and for valve-preserving procedure, 3.7% (2/54) (
P
=NS). Morbidity included 3 strokes (1%), 10 perioperative myocardial infarctions (5%), and 8 reoperations for bleeding (4%). Actuarial survival at 5, 10, 15, and 20 years was 93% (95% confidence interval [CI] = 88% to 97%), 79% (95% CI = 71% to 87%), 67% (95% CI = 57% to 79%), and 52% (95% CI = 36% to 69%), respectively. Freedom from reoperation was 72% (95% CI = 54% to 86%) at 20 years. Complications with anticoagulation occurred in 29 patients; with valve thrombosis, in 2; and with hemorrhage, in 27 (4 life threatening and 23 minor). Freedom from thromboembolism was 91% (95% CI = 77% to 98%) at 20 years. Freedom from endocarditis was 99% (95% CI = 92% to 100%) at 20 years. Multivariate analysis revealed preoperative mitral valve regurgitation (+3 to 4) and older age to be significant predictors of late death (
P
≤0.005), and Marfan syndrome, initial valve-preserving aortic root reconstruction, and need for a concomitant procedure at initial operation to be significant predictors of the need for reoperation (
P
≤0.01).

Conclusions—

Aortic root replacement for aortic root aneurysms can be done with low morbidity and mortality. Composite valve conduit reconstruction resulted in a durable result. There were few serious complications related to the need for long-term anticoagulation or a prosthetic valve. Reoperation was most commonly required because of failure of the aortic valve when a valve-preserving aortic root reconstruction was performed or for other cardiac or aortic disease elsewhere.
The Internet as Distributor and Mirror of Religious and Ritual Knowledge
Authors: Krueger Oliver
Published: August 2004

Since the early 1990s, religious movements appeared on the Internet and introduced new forms of communication in ritual and dogma. Their Internet sites present different dogmatic, institutional, and other aspects of their religion; provide interactive communications and religious services; or simply sell religious items. This paper puts forth the argument that the gaining of ritual and dogmatic knowledge is losing its dependence on direct social interaction in a spatial community, and increasingly relies on Internet-based discourse in religious newsgroups and other discussion forums. Nevertheless, for migrant communities in the diaspora (Zoroastrians, Hindus, and adherents of Afro-American religions), the Internet appears to be offering a new opportunity for re-establishing the spatial bonds of the lost religious community. In other cases such as that of the Wicca religion, this greater independence of traditional religious and social hierarchies encourages the development of fragmentary and syncretic forms of religion.
Asian Americans: Achievements Mask Challenges
Authors: Varma Roli
Published: August 2004

This article focuses on the existence of the "glass ceiling" to upward career mobility experienced by Asian Americans in professional occupations. It questions the recent portrayal of Asian Americans as a "model minority" who have "made it" in America. Instead, it shows that despite their good record of achievement, Asian Americans do not reach a level at which they can participate in policy and decision-making responsibilities. This article builds on the emerging glass ceiling literature by Asian American scholars, while examining social/cultural complexities, peculiarities, and nuances in private companies, government agencies, and institutions of higher education.
Virtual Warfare: The Internet as the New Site for Global Religious Conflict
Authors: Robinson Rowena
Published: August 2004

This paper explores the ways in which a resurgent Hindu fundamentalism (Hindutva) is redefining Hinduism and Hindu identities in a transnational, global context. The global project of Hindutva makes use of new global communication channels, including the Internet, and is apparently espoused by influential sections of the transnational Hindu middle class, especially in the United States. This paper examines a selected sample of Internet sites devoted to the spread of religious and fundamentalist beliefs and ideas particularly relevant to India and transnational Hinduism, and explores the ways in which the Internet is changing the shape of communities and the ways in which they represent one another. The paper puts forth the argument that in the context of globalization, the Net has become an important space for the creation of transnational religious identities. The Net is shaping religion, specifically Hinduism, in distinct ways and is the newest expression of religion's changing face. The battle for souls is being fought on Internet sites. The questions of this paper relate to the modes of representation of "other religions" as revealed particularly by Hindu sites, the ways in which Internet sites garner audiences, and the strategies they adopt to link themselves with both global audiences and local groups. A sociological analysis will reveal the shape of these discourses and link their popularity with the social and political context of globalization, a liberalized economy, and the organization of religious practice in post1990s India.
Capitalisms: Asian-European Dialogue after Enron
Authors: Pieterse Jan Nederveen
Published: August 2004

This dicussion suggests three steps. One is to retrieve the varieties of capitalism from the propaganda that claims there is no alternative to free market capitalism. Second is to examine the growing influence of American capitalism and the diversity or convergence of capitalisms in light of Enron and related episodes. Third is to probe options for the articulation of alternative capitalisms. Looking forward, one way in which this can happen is through a substantive dialogue between Asian countries and the European Union with regard to the direction of contemporary capitalism and globalization. This line of argument can function at two levels — as a broad-brush policy direction and as opening up thinking about globalization — probing the scope for choice.
THE ABILITY/INABILITY TO EAT: DETERMINING LIFE AND DEATH IN BEL ET DRACO
Authors: Bergmann Claudia
Published: August 2004

Bel et Draco, a work of Second Temple Judaism, makes the intentional destruction of two idols by a human being the main topic of its narrative. Unlike other Second Temple texts, which discuss what idols are, how they were created by human hands, why they exist, and how they can be destroyed, Bel et Draco focuses on only one of the characteristics of the idols that will lead to their demise: their ability or inability to distinguish between and consume different types of food. This motif becomes so important for Bel et Draco that it is used in connection with almost every character appearing in the story. How this literary device is used in the description of the fate of the characters and in the establishment of a hierarchy between them is the topic of this article.
JUBILEES —BETWEEN ENOCH AND MOSES. A NARRATIVE READING
Authors: Kvanvig Helge
Published: August 2004

There is no doubt that the biblical story in Genesis and Exodus, extending from creation to Sinai, forms the backbone of the narrative in Jubilees. Often analyses of Jubilees concentrate on this aspect, without paying sufficient attention to the narrative design in Jubilees itself. In this article some common tools in narratology are applied to focus on Jubilees as a whole. In the narrative structures it appears that the Enochic traditions are formative. Moses is placed in the front of the narrative as a witness not to the torah of the Pentateuch, but to a narrative shaped to give room for the Enochic traditions. Thus Jubilees mediates between the Mosaic and Enochic traditions, using Moses to emphasise the importance of Enoch. The two figures represent two different attitudes toward revelation, the unique concentration on Sinai as the centre of history and the common mythical world-view that the foundational events took place in primeval time.
The Effect of Estrogen on Ovine Anterior Cruciate Ligament Fibroblasts
Authors: Seneviratne Aruna , Attia Erik , Williams Riley J. , Rodeo Scott A. , Hannafin Jo A.
Published: August 2004

Estrogen has been implicated as a causal factor for anterior cruciate ligament injuries in women. Studies have demonstrated a decrease in anterior cruciate ligament fibroblast proliferation and collagen synthesis at supraphysiologic levels of estrogen in a rabbit model.

Hypothesis

The authors hypothesized that physiologic levels of estrogen would have no significant effect on anterior cruciate ligament fibroblast proliferation and collagen synthesis in an ovine model.

Methods

Anterior cruciate ligament fibroblasts were isolated from sheep knees using routine cell culture methods. The cells were exposed to 17β-estradiol at physiologic concentrations of 2.2, 5, 15, 25, 250, and 2500 pg/ml. Cell proliferation was determined by cell counts on days 4 and 6. Collagen synthesis was determined by 3H-proline incorporation on day 4. Immunohistochemistry was performed to detect estrogen receptors.

Results

Immunohistochemistry demonstrated the presence of estrogen receptors in ovine anterior cruciate ligament fibroblasts. There was no significant difference in anterior cruciate ligament fibroblast proliferation or collagen synthesis regardless of 17β-estradiol concentration.

Conclusions

Based on results of this study, and given the low turnover of collagen in ligaments, it is unlikely that a 2- to 3-day per month increase in circulating estrogen would result in rapid, clinically significant alterations in material properties ofthe anterior cruciate ligament in vivo. The etiology of noncontact anterior cruciate ligament injuries is complex and multifactorial in nature, meriting further investigation.
Evidence of Subclinical Medial Collateral Ligament Injury and Posteromedial Impingement in Professional Baseball Players
Authors: Kooima Cynthia L. , Anderson Kyle , Craig Joseph V. , Teeter Douglas M. , van Holsbeeck Marnix
Published: August 2004

Background

Recognition and treatment of elbow conditions such as medial collateral ligament injury and posteromedial impingement are increasing in throwing athletes. Magnetic resonance imaging may provide pivotal information in the management of these athletes. Knowledge of the utility of magnetic resonance imaging has become widespread throughout the baseball community. However, data on the frequency and extent of asymptomatic magnetic resonance imaging findings in the elbows of this throwing population are lacking.

Hypothesis

Abnormalities in the throwing elbows of asymptomatic professional baseball players compared to the nonthrowing elbows are frequently seen in magnetic resonance images.

Study Design

Descriptive anatomical study.

Methods

Sixteen asymptomatic professional baseball players with no history of injury underwent bilateral elbow magnetic resonance imaging using a standardized sequencing protocol. The magnetic resonance images were reviewed, in a blinded fashion, by 2 musculoskeletal radiologists and 1 orthopaedic surgeon.

Results

Medial collateral ligament abnormalities (including thickening, signal heterogeneity, or discontinuity) were present in 87% of players’ dominant elbows. Findings consistent with posteromedial impingement were present in 13 of 16 subjects. There was a significant correlation between medial collateral ligament thickening and posteromedial subchondral sclerosis (P = .04). The throwing elbow was correctly identified in all 16 subjects. No significant correlation between magnetic resonance imaging findings and age could be detected.

Conclusions

This study demonstrates a high rate of abnormal magnetic resonance imaging findings in asymptomatic throwers’ elbows. These baseline findings must be considered when magnetic resonance imaging is being used as a factor in treatment decisions.
Femoral Press-Fit Fixation of the Hamstring Tendons for Anterior Cruciate Ligament Reconstruction
Authors: Jagodzinski Michael , Behfar Vahid , Hurschler Christof , Albrecht Knut , Krettek Christian , Bosch Ulrich
Published: August 2004

Background

Press-fit fixation of patellar tendon–bone anterior cruciate ligament autografts is an interesting technique because no hardware is necessary. For hamstring tendon grafts, no biomechanical data exist of a press-fit procedure.

Hypothesis

Press-fit femoral fixation of hamstring tendons is mechanically equivalent to press-fit patellar tendon–bone fixation.

Study Design

Controlled laboratory study.

Methods

Patellar and hamstring tendons of 30 human cadavers (age, 53.8 ± 18.0 years) were used. An outside-in press-fit fixation with a knot in the semitendinosus and gracilis tendons and an inside-out and outside-in fixation with the tendons wrapped around a bone block were compared with patellar tendon–bone press-fit fixation in 30 ovine femora. Constructs were cyclically strained and then loaded until failure. Maximum load to failure, stiffness, and elongation during failure testing and cyclical loading were investigated.

Results

The maximum load to failure was 561 ± 309 N for the patellar tendon, 599 ± 234 N for the semitendinosus/gracilis tendons knot construct, 678 ± 231 for the semitendinosus/gracilis tendons bone construct inserted outside in, and 339 ± 236 for the semitendinosus/gracilis tendons bone construct inserted inside out (inferior to the others; analysis of variance, Dunn test, P < .01). Stiffness of the constructs averaged 134 ± 32 N/mm for the patellar tendon, 124 ± 21 N/mm for the knot construct, 118 ± 27 N/mm for the outside-in fixation, and 117 ± 23 N/mm for inside-out fixation. Elongation during initial cyclical loading was 0.7 ± 0.6 mm for the patellar tendon, 1.6 ± 0.5 mm for the knot construct, 1.9 ± 1.2 mm for the outside-in fixation, and 1.9 ± 0.9 mm for the inside-out fixation (significantly larger for all semitendinosus/gracilis tendon techniques, P < .05).

Conclusions

Failure loads for the semitendinosus/gracilis tendons bone construct inserted outside in and the semitendinosus/gracilis tendons knot construct were within the confidence interval of the patellar tendon press-fit fixation. All semitendinosus/gracilis tendon graft techniques exhibited larger elongation during initial cyclical loading than the patellar tendon graft. There was no difference in stiffness between all techniques.

Clinical Relevance

Two of the 3 hamstring press-fit fixation techniques showed loads to failure similar to the patellar tendon fixation. Preconditioning of the constructs is critical. These results must be interpreted with care because of high standard deviations.
Force Measurements on the Fibular Collateral Ligament, Popliteofibular Ligament, and popliteus Tendon to Applied Loads
Authors: LaPrade Robert F. , Tso Andy , Wentorf Fred A.
Published: August 2004

Background

Little information is known about the forces seen on the main individual structures of the posterolateral knee to applied loads. This information is needed to determine which structures should be reconstructed and also the relative strengths needed for reconstruction grafts.

Purpose

To determine in vitro forces in the fibular collateral ligament, popliteofibular ligament, and popliteus tendon for various posterolateral knee loading conditions.

Study Design

Cadaveric study.

Results

The fibular collateral ligament was loaded in varus, internal rotation, and external rotation. The highest amount of force seen on the fibular collateral ligament was at 0° of knee flexion with external rotation, with the mean load response to external rotation significantly less at 90°. Fibular collateral ligament varus load response at 0°, 30°, and 60° was fairly constant, with a significant decrease at 90° compared to 30° of knee flexion. The popliteus tendon and popliteofibular ligament were loaded with an external rotation moment and were noted to have similar loading patterns. The mean load response on both the popliteus tendon and the popliteofibular ligament peaked at 60° of knee flexion. The mean popliteus tendon and popliteofibular ligament load response at 0° was significantly less than the mean load response at 30°, 60°, and 90° of knee flexion.

Conclusions

High relative loads were seen on the fibular collateral ligament with varus and external rotation and on the popliteus tendon and popliteofibular ligament, with external rotation. A reciprocal relationship of load sharing in external rotation depending on knee flexion angle was revealed that has not been previously reported. The force on the fibular collateral ligament with external rotation loads was higher than the load on the popliteus complex at lower flexion angles, with the popliteus complex having higher load sharing at 60° and 90° of knee flexion. These results provide a measure of the potential for failure of these structures with joint loading and guidelines for both graft strength requirements for surgical reconstructions and postoperative rehabilitation protocols.
Radiographic Changes in the Hands and Fingers of Young, High-Level Climbers
Authors: Schöffl Volker , Hochholzer Thomas , Imhoff Andreas
Published: August 2004

Background

In the past few years, competition climbing has grown in popularity, and younger people are being drawn to the sport.

Hypothesis

Although the radiographic changes in long-term climbers are known, there are little data available on young climbers. The question arises as to whether climbing at high levels at a young age leads to radiographic changes and possibly an early onset of osteoarthrosis in the finger joints.

Study Design

Cross-sectional study.

Methods

Nineteen members of the German Junior National Team and 18 recreational climbers were examined clinically and through radiographs. For comparison, radiographs of 12 young nonclimbers (control group) were collected. Radiographs were evaluated using a standard protocol. For evaluation of the physiologic adaptation, the cortical thickness of the middle phalanx and the Barnett Nordin index were analyzed. The results were compared between the 3 groups and against radiographs of 140 long-term, experienced climbers.

Results

Six climbers (32%) of the German Junior National Team presented a decreased range of motion for the small finger joints; none of the recreational climbers showed this decrease. In 47% of the German Junior National Team and 28% of the recreational climbers, stress reactions could be found: cortical hypertrophy (26% German Junior National Team, 11% recreational climbers), subchondral sclerosis (47% German Junior National Team, 6% recreational climbers), broadened base of the proximal interphalangeal joint (42% German Junior National Team, 28% recreational climbers), and broadened base of the distal interphalangeal joint (16% German Junior National Team, 0 recreational climbers). Signs of an early stage of osteoarthrosis were seen in 1 climber in each group. The control group showed no radiologic abnormalities. The Barnett Nordin index was 0.49 ± 0.05 in German Junior National Team, 0.49 ± 0.07 in recreational climbers, and 0.48 ± 0.08 in the control group. There was no statistically significant difference on the Barnett Nordin index between the groups (German Junior National Team/recreational climbers: P = .89; German Junior National Team/control group: P = .58; recreational climbers/control group: P = .55).

Conclusions

Intensive training and climbing lead to adaptive reactions; nevertheless, osteoarthrotic changes are rare.
Effectiveness of Extracorporeal Shock Wave Therapy in the Treatment of Previously Untreated Lateral Epicondylitis
Authors: Chung Bryan , Wiley J. Preston
Published: August 2004

Background

Extracorporeal shock wave therapy is a relatively new therapy used in the treatment of chronic tendon-related pain. Few randomized controlled trials have been performed on it, and no studies have examined the effectiveness of extracorporeal shock wave therapy as a frontline therapy for tendon-related pain.

Hypothesis

Subjects treated with active extracorporeal shock wave therapy will have higher rates of treatment success than subjects treated with sham extracorporeal shock wave therapy.

Design

Double-blind randomized controlled trial.

Methods

Sixty subjects who had previously untreated lateral epicondylitis for less than 1 year and more than 3 weeks were included in this study. Subjects were randomly allocated to receive 1 session per week for 3 weeks of either sham or active extra-corporeal shock wave therapy. Subjects in the active therapy group received 2000 pulses (energy flux density, 0.03-0.17 mJ/mm2). All subjects were provided with a forearm-stretching program. After 8 weeks of therapy, subjects were classified as either treatment successes or treatment failures according to fulfillment of all 3 criteria: (1) at least a 50% reduction in the over-all pain visual analog scale score, (2) a maximum allowable overall pain visual analog scale score of 4.0 cm, and (3) no use of pain medication for elbow pain for 2 weeks before the 8 week follow-up. Visual analog scale scores were also collected for pain at rest, during sleep, during activity, at its worst, and at its least, as well as for quality of life (using the EuroQoL questionnaire) and grip strength.

Results

Success rates in the sham and active therapy groups were 31% and 39%, respectively. No significant difference was detected between groups (χ21 = 0.3880, P = .533). Mean change in quality of life over 8 weeks was an increase of 1.3 and 3.3 for sham and active therapy groups, respectively, and mean change in grip strength over 8 weeks was an increase of 7.4 kg and 6.8 kg for sham and active therapy groups, respectively.

Conclusions

Despite improvement in pain scores and pain-free maximum grip strength within groups, there does not appear to be a meaningful difference between treating lateral epicondylitis with extracorporeal shock wave therapy combined with forearm-stretching program and treating with forearm-stretching program alone, with respect to resolving pain within an 8-week period of commencing treatment.
Elbow Medial Ulnar Collateral Ligament Insufficiency Alters Posteromedial Olecranon Contact
Authors: Ahmad Christopher S. , Park Maxwell C. , ElAttrache Neal S.
Published: August 2004

Background

The effect of elbow medial ulnar collateral ligament injury on posteromedial compartment contact is unknown.

Hypothesis

Medial ulnar collateral ligament injury causes altered contact area and pressure in the posteromedial compartment of the elbow.

Study Design

Controlled laboratory study.

Methods

Seven elbow cadaveric specimens were tested in an apparatus that positioned the elbow at 30° and 90° of flexion. Partial and full tears were simulated by releasing the medial ulnar collateral ligament. Pressure-sensitive film was placed in the posteromedial compartment for each condition. Valgus torques of 1.25 and 2.0 N.m were applied for each ligament condition, and kinematic data were obtained at each flexion angle using a 3-dimensional digitizer.

Results

Both ligament condition and valgus load had significant effects on contact area and pressure (P < .05). For a given load and flexion angle, the contact area decreased and the pressure increased with increasing medial ulnar collateral ligament insufficiency. Within these trends, statistical significance was found at 30° of elbow flexion for both area and pressure (P < .05); at 90° of elbow flexion, increasing medial ulnar collateral ligament insufficiency did not significantly affect contact area or pressure (P > .05).

Discussion

Medial ulnar collateral ligament insufficiency alters contact area and pressure between the posteromedial trochlea and olecranon and helps explain the development of posteromedial osteophytes.
Parecoxib Impairs Early Tendon Repair but Improves Later Remodeling
Authors: Virchenko Olena , Skoglund Björn , Aspenberg Per
Published: August 2004

Background

Cyclooxygenase-2 inhibitors inhibit bone repair.

Hypothesis

Cyclooxygenase inhibitors might also have a negative effect on early tendon repair, although a positive effect on late tendon repair previously has been shown.

Study Design

Controlled laboratory study.

Methods

Achilles tendon transection was performed on 80 rats. Sixty rats were given daily intramuscular injections of either parecoxib (6.4 mg/kg body weight) or saline for the first 5 days after surgery and sacrificed either at 8 or 14 days. The remaining 20 rats were given intramuscular parecoxib or saline injections from day 6 until sacrifice at 14 days.

Results

At 8 days, early parecoxib treatment caused a 27% decrease in force at failure (P = .007), a 25% decrease in maximum stress (P = .01), and a 31% decrease in energy uptake (P = .05). Stiffness and transverse area were not significantly affected. At 14 days, early parecoxib treatment caused a decrease in stiffness (P = .004). In contrast to early treatment, late parecoxib treatment caused a 16% decrease in cross-sectional area (P = .03) and a 29% increase in maximum stress (P = .04).

Conclusions

During early tendon repair, a cyclooxygenase-2 inhibitor had a detrimental effect. During remodelling, however, inflammation appears to have a negative influence, and cyclooxygenase-2 inhibitors might be of value.

Clinical Relevance

The results suggest that cyclooxygenase-2 inhibitors should be used with care in the early period after tendon injury.
Cannulated Screw Fixation of Jones Fractures
Authors: Reese Keri , Litsky Alan , Kaeding Christopher , Pedroza Angela , Shah Nilesh
Published: August 2004

Background

Traditional nonsurgical treatment of Jones fractures has high rates of delayed union, nonunion, and refracture. Internal fixation has become the treatment of choice in athletes and active patients.

Purpose

The purpose of this study was (1) to review the short- and long-term clinical results of cannulated screw fixation of Jones fractures and (2) to perform a biomechanical evaluation of fatigue failure characteristics of several types of screws used in the fixation of Jones fractures.

Study Design

Retrospective case series and in vitro biomechanical study.

Methods

Ten male and 5 female patients with Jones fractures fixed with cannulated screws ranging from 4 mm to 6.5 mm in diameter were evaluated by chart review, review of radiographs, and telephone interview. Mean follow-up from surgery to phone survey was 34 months. Screws ranging in size from 2.7 mm to 7.3 mm, both cannulated and noncannulated, stainless steel and titanium, were tested in the laboratory by cyclic loading to 250 N up to a maximum of 200 000 cycles.

Results

Mean time to healing as shown on radiographs and by full activity after surgery were 7.3 and 7.9 weeks, respectively. All patients were able to return to their previous levels of activity. Screw fatigue data showed that the number of cycles to failure increased with increasing screw diameter. For 4-mm screws, mean number of cycles to failure was 4308 for cannulated titanium screws, 22 012 for cannulated stainless steel screws, and 44 523 for noncannulated stainless steel screws.

Conclusions

In our patients, cannulated screw fixation of Jones fractures was a procedure that was reliable, had low morbidity, and afforded athletes a quick return to activity.

Clinical Relevance

The laboratory study suggests that the largest screw possible should be used for surgical fixation of these fractures and that screws less than 4 mm in diameter should be used with caution.
Bone Anchors or Interference Screws?
Authors: Jeys Lee , Korrosis Sotiris , Stewart Todd , Harris Nicholas J.
Published: August 2004

Background

Autograft stabilization uses free semitendinosus tendon grafts to anatomically reconstruct the anterior talofibular ligament. Study aims were to evaluate the biomechanical properties of Mitek GII anchors compared with the Arthrex Bio-Tenodesis Screw for free tendon reconstruction of the anterior talofibular ligament.

Null Hypothesis

There are no differences in load to failure and percentage specimen elongation at failure between the 2 methods.

Study Design

Controlled laboratory study using porcine models.

Methods

Sixty porcine tendon constructs were failure tested. Re-creating the pull of the anterior talofibular ligament, loads were applied at 70° to the bones. Thirty-six tendons were fixed to porcine tali and tested using a single pull to failure; 10 were secured with anchors and No. 2 Ethibond, 10 with anchors and Fiber Wire, 10 with screws and Fiberwire, and 6 with partially gripped screws. Cyclic preloading was conducted on 6 tendons fixed by anchors and on 6 tendons fixed by screws before failure testing. Two groups of 6 components fixed to the fibula were also tested.

Results

The talus single-pull anchor group produced a mean load of 114 N and elongation of 37% at failure. The talus single-pull screw group produced a mean load of 227 N and elongation of 22% at failure (P < .05). Cyclic preloading at 65% failure load before failure testing produced increases in load and decreases in elongation at failure. Partially gripped screws produced a load of 133 N and elongation of 30% at failure. The fibula model produced significant increases in load to failure for both. The human anterior talofibular ligament has loads of 139 N at failure with instability occurring at 20% elongation.

Conclusions

Interference screw fixation produced significantly greater failure strength and less elongation at failure than bone anchors.

Clinical Relevance

The improved biomechanics of interference screws suggests that these may be more suited to in vivo reconstruction of the anterior talofibular ligament than are bone anchors.
Prospective Evaluation of the Effect of Rotator Cuff Integrity on the Outcome of Open Rotator Cuff Repairs
Authors: Klepps Steven , Bishop Julie , Lin Jason , Cahlon Oren , Strauss Alyssa , Hayes Patrick , Flatow Evan L.
Published: August 2004

Background

Open rotator cuff repairs have led to excellent clinical results; however, several studies have linked postoperative structural integrity to patient outcomes. The purpose of this study is to prospectively assess postoperative cuff integrity after open rotator cuff repair and assess its relationship to clinical outcome.

Hypothesis

Preoperative rotator cuff tear size and postoperative rotator cuff integrity are important factors in overall clinical outcomes.

Study Design

Prospective nonrandomized clinical outcomes study.

Methods

Forty-seven consecutive patients undergoing repair of full-thickness rotator cuff tears by a single surgeon were enrolled in this prospective study. A standardized evaluation was performed preoperatively and postoperatively at annual intervals. All patients underwent postoperative magnetic resonance imaging at least 1 year after surgery. Statistical evaluation was performed using paired and unpaired 2-tailed t tests for comparison.

Results

Thirty-two patients were available for evaluation. Overall, the patients experienced a significant (P < .05) improvement in their American Shoulder and Elbow Surgeons survey (40-85) and Constant (53-80) scores. The overall retear rate was 31%. Although patients with large tears preoperatively and retears postoperatively had lower overall outcomes scores, this was not significant.

Conclusion

These data support open rotator cuff repair as an effective technique that restores excellent shoulder function. The authors did not find postoperative cuff integrity to have a significant effect on outcomes when compared with those with an intact cuff. In fact, those with a retear still had a significant improvement in all clinical areas assessed, including strength.