bluuebunny/crossref_metadata_2025 huggingface dataset:
Positron Emission Tomography Examination of Cerebral Blood Flow and Glucose Metabolism in Young CADASIL Patients
Authors: Tuominen Susanna , Miao Qing , Kurki Timo , Tuisku Seppo , Pöyhönen Minna , Kalimo Hannu , Viitanen Matti , Sipilä Hannu T. , Bergman Jörgen , Rinne Juha O.
Published: March 2004

Background and Purpose—

CADASIL causes repeated ischemic strokes leading to subcortical vascular dementia. The purpose of this study was to assess whether cerebral blood flow (CBF) and regional cerebral metabolic rates of glucose (rCMR
gluc
) in CADASIL patients are affected in early adulthood.

Methods—

CBF and rCMR
gluc
were examined with positron emission tomography in correlation with magnetic resonance imaging (MRI) in 14 adult (19 to 41 years) CADASIL patients with the
Notch3
R133C mutation. Seven patients had experienced transient ischemic attack and 3 had experienced ≥1 strokes.

Results—

The mean CBF in the CADASIL patients was significantly lower in both frontal (
P
=0.019) and occipital (
P
=0.009) white matter (WM) than those in the controls. CBF decreased significantly with increased severity of the disease. The patients had lower mean rCMR
gluc
values than the controls, although differences were not statistically significant. Sum scores of semiquantitative MRI rating scale (Scheltens) correlated significantly with WM CBF but not with rCMR
gluc
.

Conclusions—

In CADASIL, there is an early and significant decrease in the CBF of WM associated with simultaneous MRI changes. These are obviously caused by the arteriopathy in long penetrating arteries and indicate early tissue damage, also expressed as impaired rCMR
gluc
in the WM.
Mechanical Thrombolysis in Acute Ischemic Stroke With Endovascular Photoacoustic Recanalization
Authors: Berlis Ansgar , Lutsep Helmi , Barnwell Stan , Norbash Alexander , Wechsler Lawrence , Jungreis Charles A. , Woolfenden Andrew , Redekop Gary , Hartmann Marius , Schumacher Martin
Published: March 2004

Background and Purpose—

We present the results of endovascular photoacoustic recanalization (EPAR) treatment for acute ischemic stroke from the Safety and Performance Study at 6 centers in Europe and North America. The objectives of mechanical thrombolysis are rapid vessel recanalization and minimal use of chemical thrombolysis.

Methods—

This study was a prospective, nonrandomized study. The National Institutes of Health Stroke Scale (NIHSS) score and the modified Rankin Scale (mRS) score were recorded before treatment. The presence of recanalization was assessed by angiography. To measure outcome, follow-up examinations were performed at 24 hours, 7 days, and 30 days after stroke onset.

Results—

Thirty-four patients (median NIHSS 19) were enrolled. Ten patients had internal carotid artery occlusion, 12 patients had middle cerebral artery occlusion, 11 patients had vertebrobasilar occlusion, and 1 patient had posterior cerebral artery occlusion. The overall recanalization rate was 41.1% (14/34). Complete EPAR treatment was possible in 18 patients (median NIHSS 18), with vessel recanalization in 11 patients (61.1%) after EPAR. The average lasing time was 9.65 minutes. Incomplete EPAR treatment (16/34, median NIHSS 19) was defined as intention to treat with EPAR and that the EPAR microcatheter entered the patient. Additional treatment with intraarterial application of rTPA occurred in 13 patients. An adverse event associated with use of the device occurred in 1 patient. Symptomatic hemorrhages occurred in 2 patients (5.9%). The mortality rate was 38.2%.

Conclusions—

This study demonstrates the safety and technical feasibility of EPAR. This new technique may provide another treatment option in the therapeutic armamentarium for patients with acute ischemic stroke.
Volume-Regulated Anion Channels Are the Predominant Contributors to Release of Excitatory Amino Acids in the Ischemic Cortical Penumbra
Authors: Feustel Paul J. , Jin Yiqiang , Kimelberg Harold K.
Published: March 2004

Background and Purpose—

Release of excitatory amino acids (EAA) is considered a cause of neuronal damage in ischemia. We investigated the sources and mechanisms of EAA release using microdialysis in regions of incomplete ischemia where perfusion was reduced by 50% to 80%, by applying inhibitors of volume-regulated anion channels (VRACs) and the GLT-1 glutamate transporter.

Methods—

Reversible middle cerebral artery occlusion (rMCAo) was induced in anesthetized rats using the intraluminal suture technique. Microdialysate concentrations of glutamate, aspartate, and taurine were measured before, during 2 hours of rMCAo, and for 2 hours after rMCAo. Vehicle, dihydrokainate (DHK, 1 mmol/L), a GLT-1 inhibitor, or tamoxifen (50 μmol/L), a VRAC inhibitor, were administered continuously via the dialysis probes starting one hour prior to ischemia.

Results—

During incomplete ischemia, dialysate glutamate levels averaged 1.74±0.31 μmol/L (SEM) in the control group (n=8), 2.08±0.33 μmol/L in the DHK group (n=7), and were significantly lower at 0.88±0.30 μmol/L in the tamoxifen group (n=9;
P
<0.05). As perfusion returned toward baseline levels, EAA levels declined in the vehicle and tamoxifen-treated animals but they remained elevated in the DHK-treated animals.

Conclusions—

In contrast to previous results in severely ischemic regions, DHK did not reduce EAA release in less severely ischemic brain, suggesting a diminished role for transporter reversal in these areas. These findings also support the hypothesis that in regions of incomplete ischemia, release of EAAs via VRACs may play a larger role than reversal of the GLT-1 transporter.
Prehospital Neuroprotective Therapy for Acute Stroke
Authors: Saver Jeffrey L. , Kidwell Chelsea , Eckstein Marc , Starkman Sidney
Published: March 2004

Background and Purpose—

To demonstrate that paramedic initiation of intravenous magnesium sulfate (Mg) in the field in focal stroke patients is feasible, safe, and yields significant time-savings compared with in-hospital initiation of neuroprotective therapy.

Methods—

We performed an open-label clinical trial. Inclusion criteria were: (1) likely stroke as identified by the Los Angeles Prehospital Stroke Screen; (2) age 45 to 95; and (3) treatment initiation within 12 hours of symptom onset. Paramedics initiated 4 g Mg loading dose in the field, followed by 16 g over 24 hours in hospital.

Results—

Twenty patients were enrolled, with mean age 74 (range 44 to 92), and 50% were male. Final diagnosis was acute cerebrovascular disease in all (ischemic 80%, hemorrhagic 20%). Study agent infusion began a median of 100 minutes after symptom onset (range 24 to 703), and 70% received study agent within 2 hours of onset. The interval from paramedic arrival on scene to study agent start was: field-initiated, 26 minutes (range 15 to 64) versus in-hospital initiated (historic controls), 139 minutes (range 66 to 300;
P
<0.0001). Paramedics rated patient status on hospital arrival as improved 20%, worsened 5%, and unchanged 75%. Median NIHSS on hospital arrival was 11 in all patients and 16 in patients unchanged since field treatment start. Good functional outcome at 3 months (Rankin ≤ 2) occurred in 60%. No serious adverse events were associated with field therapy initiation.

Conclusions—

Field initiation of Mg sulfate in acute stroke patients is feasible and safe. Prehospital trial conduct substantially reduces on-scene to needle time and permits hyperacute delivery of neuroprotective therapy.
Alcohol Consumption and Risk of Stroke Among Middle-Aged Men: The JPHC Study Cohort I
Authors: Iso Hiroyasu , Baba Shunroku , Mannami Toshifumi , Sasaki Satoshi , Okada Katsutoshi , Konishi Masamitsu , Tsugane Shoichiro
Published: March 2004

Background and Purpose—

The impact of light-to-moderate alcohol consumption on risk of stroke has not been well examined in a single study, although the effect is hypothesized to differ among stroke subtypes from meta-analyses.

Methods—

A total of 19 544 men aged 40 to 59 years living in communities were followed-up from 1990 to 1992 to the end of 2001 in the Japan Public Health Center-based Prospective Study on Cancer and Cardiovascular Disease (JPHC Study).

Results—

After 214 504 person-years of follow-up, 694 incident strokes were documented, of which 611 were confirmed by imaging studies or autopsy, including 219 intraparenchymal hemorrhages, 73 subarachnoid hemorrhages, and 319 ischemic strokes. Alcohol consumption was positively associated with age-adjusted risk of total stroke with a 68% excess risk among drinkers of ≥450 g ethanol per week compared with occasional drinkers. This excess risk was confined primarily to hemorrhagic stroke, which remained statistically significant even after controlling for hypertension and other cardiovascular risk factors (RR: 2.15; 95% CI: 1.22 to 3.79). There was a lower risk of ischemic stroke, more specifically lacunar infarction, a higher risk of hemorrhagic stroke, and no excess risk of total stroke among drinkers of 1 to 149 g ethanol per week compared with occasional drinkers; the respective multivariate RR (95% CI) was 0.59 (0.37 to 0.93), 0.43 (0.22 to 0.87), 1.73 (0.98 to 3.07), and 0.98 (0.71 to 1.36).

Conclusions—

We found differential effects of light-to-moderate alcohol consumption on risks of hemorrhagic and ischemic strokes among middle-aged men. Light-to-moderate alcohol consumption, ie, ≤2 drinks per day, does not raise the risk of total stroke.
Morphometry of Medial Gaps of Human Brain Artery Branches
Authors: Canham Peter B. , Finlay Helen M.
Published: March 2004

Background and Purpose—

The bifurcation regions of the major human cerebral arteries are vulnerable to the formation of saccular aneurysms. A consistent feature of these bifurcations is a discontinuity of the tunica media at the apex of the flow divider. The objective was to measure the 3-dimensional geometry of these medial gaps or “medial defects.”

Methods—

Nineteen bifurcations and 2 junctions of human cerebral arteries branches (from 4 male and 2 female subjects) were formalin-fixed at physiological pressure and processed for longitudinal serial sectioning. The apex and adjacent regions were examined and measurements were made from high-magnification photomicrographs, or projection microscope images, of the gap dimensions at multiple levels through the bifurcation.

Results—

Plots were made of the width of the media as a function of distance from the apex. The media at each edge of the medial gap widened over a short distance, reaching the full width of the media of the contiguous daughter vessel. Medial gap dimensions were compared with the planar angle of the bifurcation, and a strong negative correlation was found, ie, the acute angled branches have the more prominent medial gaps.

Conclusions—

A discontinuity of the media at the apex was seen in all the bifurcations examined and was also found in the junction regions of brain arteries. We determined that the gap width is continuous with well-defined dimensions throughout its length and average length-to-width ratio of 6.9. The gaps were generally centered on the prominence of the apical ridge.
Prothrombin Fragment 1+2 Is Associated With Carotid Intima-Media Thickness in Subjects Free of Clinical Cardiovascular Disease
Authors: Páramo J.A. , Orbe J. , Beloqui O. , Benito A. , Colina I. , Martinez-Vila E. , Diez J.
Published: March 2004

Background and Purpose—

Thrombin, a central enzyme in the clotting cascade, plays a role not only in thrombosis but also in the progression of atherosclerosis. We studied the relationship between prothrombin fragment 1+2 (F1+2), a specific marker of thrombin generation in vivo, and carotid intima-media thickness (IMT), an index of subclinical atherosclerosis.

Methods—

We examined 181 asymptomatic middle-aged subjects (mean age 55.6 years, 76.7% men) free of overt clinical atherosclerotic disease. F1+2 was measured by enzyme-linked immunosorbent assay and IMT by duplex ultrasonography of carotid artery. Multiple linear regression analysis was used to assess the relationship between the 2 parameters.

Results—

Compared with individuals in the lowest tertile of F1+2, those in the upper tertile (>0.55 nmol/L) showed significantly higher IMT (
P
<0.01). In correlation analysis, a positive relationship was found between plasma F1+2 and carotid IMT. F1+2 also correlated positively with cholesterol (
P
<0.008) and low-density lipoprotein cholesterol (
P
<0.005), but not with blood pressure or body mass index. In the multivariate analysis, the association of F1+2 with carotid IMT remained significant (
P
<0.001) after adjustment for age, sex, body mass index, systolic blood pressure, cholesterol, diabetes, and smoking.

Conclusions—

In a population sample of adults without clinically overt atherosclerotic disease, the plasma levels of F1+2 were significantly associated with carotid IMT, suggesting a relationship between thrombin generation and the development atherosclerosis.
THE FIGURE OF EVE IN ROMANS 7:5-25
Authors: Busch Austin
Published: March 2004

Rom. 7:7-25 functions as a prosopopoiia in which Paul rhetorically assumes the identity of Eve in the scene of the primeval transgression. While most Hellenistic biblical interpreters associated Eve with "feminine" passivity, Paul in Romans 7 (and to a lesser degree in 2 Corinthians 11) calls this simplistic association into question by drawing attention to an element of ("masculine") activity in her experience that other interpreters either overlooked or could not satisfactorily account for in their interpretations of her story. In Rom. 7:7-13 Eve in the scene of the primeval transgression (Genesis 2-3) becomes a figure of passivity and activity paradoxically conflated. In the following verses (7:14-25) Paul manipulates this conflation in order to illustrate the ego or self split under sin. Observing the unique way in which Paul employs the figure of Eve in Rom. 7:5-25 allows us to read the passage as a meditation on the primeval transgression offering a new perspective on the relationship between the self under sin and the law. This relationship bears deep structural similarities to the relationship of the infant to its mirror image that Jacques Lacan examines in his lecture "The Mirror Stage as Formative of the Function of the I" and a comparison between the two will clarify Paul's discussion of the connection between the self, the law, and sin in Rom. 7:5-25.
Ironic Representation, Authorial Voice, and Meaning in Qohelet
Authors: Sharp Carolyn
Published: March 2004

The book of Qohelet presents a literarily noteworthy double voicing and differing perspectives by means of the sage "Qohelet" and the Epilogist. Interpreters have responded with redactional schemas, on the one hand, and with literary defenses of the rhetorical unity of the book, on the other. Aligned with literary studies that discern a rhetorical purpose underlying the fictional character of the sage, the present essay argues for a governing metanarratological irony mediated by the construction of the persona of "Qohelet." Building on appraisals of key functions of irony by Kierkegaard, Booth, and Hutcheon, this study analyzes ways in which ironic representation and authorial voice work rhetorically in the book of Qohelet. Clues to the pervasive irony informing the representation of the persona of "Qohelet" can be discerned in the unreliability of "Qohelet's" voice, in the hyperbole that shades over into caricature regarding "Qohelet's" claims about himself, and in the epistemologically illegitimate way in which "Qohelet" grounds his global skepticism in his avowedly unique and un(con)testable personal experience. Intertextual allusions to the Garden of Eden story are mustered in support of the position that the book's ironic perspective inscribes in the body of "Qohelet" and in the corpus of the text the catastrophic effects of the human choice to privilege the sapiential quest over halakhic obedience. Implications of the present analysis press a challenge to postmodernist hermeneutical strategies that fail to address adequately the issue of the competent decoding of authorial intention in ironic texts.
Toward an Integrated Assessment of the Impacts of Extreme Wind Events on Barrow, Alaska
Authors: Lynch A. H. , Curry J. A. , Brunner R. D. , Maslanik J. A.
Published: March 2004

Warming of the arctic climate is having a substantial impact on the Alaskan North Slope coastal region. The warming is associated with increasing amounts of open water in the arctic seas, rising sea level, and thawing permafrost. Coastal geography and increasing development along the coastline are contributing to increased vulnerability of infrastructure, utilities, and supplies of food and gasoline to storms, flooding, and coastal erosion. Secondary impacts of coastal flooding may include harm to animals and their land or sea habitats, if pollutants are released. Further, Inupiat subsistence harvesting of marine sources of food, offshore resource extraction, and marine transportation may be affected. This paper describes a project to understand, support, and enhance the local decision-making process on the North Slope of Alaska on socioeconomic issues that are influenced by warming, climate variability, and extreme weather events.
MAJOR ADVANCES FORESEEN IN HUMIDITY PROFILING FROM THE WATER VAPOUR LIDAR EXPERIMENT IN SPACE (WALES)
Authors: Gerard É. , Tan D. G. H. , Garand L. , Wulfmeyer V. , Ehret G. , Di Girolamo P.
Published: March 2004

The need for an absolute standard for water vapor observations, in the form of a global dataset with high accuracy and good spatial resolution, has long been recognized. The European Space Agency's Water Vapour Lidar Experiment in Space (WALES) mission aims to meet this need by providing high-quality water vapor profiles, globally and with good vertical resolution, using a differential absorption lidar (DIAL) system in a low earth-orbit satellite. WALES will be the first active system to measure humidity from space routinely. With launch envisaged in the 2008–2010 time frame and a minimum duration of two years, the primary mission goals are to (a) contribute to scientific research and (b) demonstrate the feasibility of longer-term operational missions. This paper assesses the benefits of the anticipated data to NWP through quantitative analysis of information content. Good vertical resolution and low random errors are shown to give substantial improvements in analysis error in one-dimensional variational data assimilation (1DVAR) comparisons with advanced infrared sounders. In addition, the vertical extent of the profiles is shown to reach 16.5 km or ~100 hPa, well above the limit of radiance assimilation (13 km or 200 hPa). Also highlighted are important applications in atmospheric sciences and climate research that would benefit from the low bias promised by spaceborne DIAL data and their complementarity to other types of humidity observations.
An Overview of the International H2O Project (IHOP_2002) and Some Preliminary Highlights
Authors: Weckwerth Tammy M. , Parsons David B. , Koch Steven E. , Moore James A. , LeMone Margaret A. , Demoz Belay B. , Flamant Cyrille , Geerts Bart , Wang Junhong , Feltz Wayne F.
Published: March 2004

The International H2O Project (IHOP_2002) is one of the largest North American meteorological field experiments in history. From 13 May to 25 June 2002, over 250 researchers and technical staff from the United States, Germany, France, and Canada converged on the Southern Great Plains to measure water vapor and other atmospheric variables. The principal objective of IHOP_2002 is to obtain an improved characterization of the time-varying three-dimensional water vapor field and evaluate its utility in improving the understanding and prediction of convective processes. The motivation for this objective is the combination of extremely low forecast skill for warm-season rainfall and the relatively large loss of life and property from flash floods and other warm-season weather hazards. Many prior studies on convective storm forecasting have shown that water vapor is a key atmospheric variable that is insufficiently measured. Toward this goal, IHOP_2002 brought together many of the existing operational and new state-of-the-art research water vapor sensors and numerical models.

The IHOP_2002 experiment comprised numerous unique aspects. These included several instruments fielded for the first time (e.g., reference radiosonde); numerous upgraded instruments (e.g., Wyoming Cloud Radar); the first ever horizontal-pointing water vapor differential absorption lidar (DIAL; i.e., Leandre II on the Naval Research Laboratory P-3), which required the first onboard aircraft avoidance radar; several unique combinations of sensors (e.g., multiple profiling instruments at one field site and the German water vapor DIAL and NOAA/Environmental Technology Laboratory Doppler lidar on board the German Falcon aircraft); and many logistical challenges. This article presents a summary of the motivation, goals, and experimental design of the project, illustrates some preliminary data collected, and includes discussion on some potential operational and research implications of the experiment.
Initial Fixation Strength of Two Bioabsorbable Pins for the Fixation of Hamstring Grafts Compared to Interference Screw Fixation
Authors: Zantop Thore , Weimann Andre , Rümmler Markus , Hassenpflug Joachim , Petersen Wolf
Published: March 2004

Background

During the early postoperative period, the fixation of a hamstring graft to the bone tunnel is the primary factor in limiting rehabilitation.

Hypothesis

The initial fixation strength of a double cross pin fixation technique is comparable with the biodegradable interference screw fixation technique.

Study Design

Experimental laboratory study.

Methods

The authors examined the initial fixation strength of two 3.3-mm bioabsorbable pins compared to interference screws for hamstring grafts in bovine knees.

Results

Analysis of yield load, maximum load, and stiffness in the single-cycle loading test showed no statistically significant differences for cross pin and interference fixation (P< .05). For cross pins and interference screws, the mean displacement under 1000 cycles to 250 N was 5.07 (±1.9) mm and 4.81 (±2.5) mm, stiffness 252 (±78) N/mm and 289 (±148) N/mm. Only grafts fixed with cross pins survived 1000 cycles to 450 N.

Conclusion

The initial fixation strength of the double cross pin technique is comparable to that of interference screw fixation with a stiffness comparable to that of the native ACL.

Clinical Relevance

Hamstring graft fixation using two cross pins provides an alternative to bioabsorbable interference screw fixation.
Prospective Evaluation of 1485 Meniscal Tear Patterns in Patients with Stable Knees
Authors: Metcalf Michael H. , Barrett Gene R.
Published: March 2004

Background

Despite emphasis on classifying meniscal tears based on healing potential of the tear, research has concentrated on unstable knees, and few reports have provided information regarding associated clinical variables in stable knees.

Purpose

To report on a large series of meniscal tears in stable knees that have been carefully mapped by tear shape and tear zones to allow comparison with meniscal tears in unstable knees.

Study Design

Prospective case series, reviewed retrospectively.

Methods

A total of 1485 meniscal tears in stable knees were evaluated. Preoperatively, each patient underwent a standardized assessment. Each tear was carefully mapped at arthroscopy. Statistical analysis was performed to determine factors that may be associated with peripheral meniscal tears.

Results

The distribution and shape of tears varied significantly within the radial and circumferential zones in this stable knee population. Five prospective variables were associated with peripheral tears: gender, presence of an effusion, positive McMurray test, varus alignment, or a loss of extension more than 5°.

Conclusions

Patient demographic information and physical examination can be useful in identifying patients who may have a peripheral meniscus tear.
Mechanical Effects of Autogenous Osteochondral Surgical Grafting Procedures and Instrumentation on Grafts of Articular Cartilage
Authors: Kuroki Hiroshi , Nakagawa Yasuaki , Mori Koji , Ikeuchi Ken , Nakamura Takashi
Published: March 2004

Purpose

To analyze the mechanical effects of autogenous osteochondral grafting procedures on articular cartilage.

Methods

The intensity, duration, and interval (indexes of stiffness, surface irregularity, and thickness) of the cartilage were assessed in a porcine model using an ultrasonic measurement system. In 7 of 12 knees, 6-mm-diameter plugs were harvested from the donor knees and grafted into 5-mm recipient holes at 3 different points per knee (21 plugs). In the remaining 5 knees, 5-mm plugs were harvested and returned to their original position (28 plugs).

Results

No significant differences in the intensity, duration, and interval of the cartilage were observed with the plugs before harvesting and after grafting by the paired ttest. The 3 indexes of the 6- and 5-mm plugs that were grafted correlated significantly with those before they were.

Conclusions

These results suggest that osteochondral graft surgery does not affect the stiffness, surface irregularity, and thickness of the cartilage of the plugs at time zero.
Comparison of Shoulder Stabilization Using Arthroscopic Transglenoid Sutures versus Open Capsulolabral Repairs
Authors: Hubbell John D. , Ahmad Sohail , Bezenoff Leigh S. , Fond Jason , Pettrone Frank A.
Published: March 2004

Background

Few long-term studies have compared the efficacy of shoulder stabilization using arthroscopic or open procedures.

Purpose

To directly compare the outcomes of shoulder stabilization using arthroscopic transglenoid sutures versus open capsulolabral repairs.

Study Design

Uncontrolled retrospective review.

Methods

Fifty patients (30 arthroscopic and 20 open) were followed for a minimum of 5 years (mean, 68 months). Pain, motion, strength, function, stability, patient satisfaction, radiographs, and ability to return to preinjury activity levels were evaluated.

Results

The arthroscopic group had a 17% (5 of 30) dislocation rate and a 60% (18 of 30) rate of instability. Sixty-seven percent (6 of 9) of patients participating in collision sports had repeat instability. Eight of 18 patients with instability required open repair for persistent symptoms. There were no limitations of motion following arthroscopic stabilization. The open group had no episodes of dislocations or instability. Forty-five percent (9 of 20) had some loss of external rotation (range, 10°-40°) with a mean loss of 18. The one failure in this group had a 40° loss of external rotation and difficulty with recreational activity. No patients participating in collision sports had repeat instability.

Conclusion

We recommend open stabilization for patients participating in collision sports (for example, football, wrestling) or activities where better stability is required. For those participating in sports where performance may be compromised by loss of external rotation (such as swimming), newer arthroscopic techniques are recommended.
A Biomechanical Comparison of Repair Techniques for Type II SLAP Lesions
Authors: DiRaimondo Carl A. , Alexander Jerry W. , Noble Philip C. , Lowe Walter R. , Lintner David M.
Published: March 2004

Background

Multiple options exist for repair of superior labral tears.

Purpose

To compare commonly used fixation techniques for superior labral tears.

Study Design

Biomechanical cadaveric study.

Methods

A comparison of the initial strengths of fixation for type II superior labral anterior posterior (SLAP) lesions was performed in three cadaveric shoulder groups, each containing seven specimens. Two groups were repaired with screw-in anchors; one group had vertical sutures, the other horizontal. Group 3 was repaired using bioabsorbable tacks. Cyclic traction was applied to the biceps tendon. Repair failure (2 mm of permanent displacement) and ultimate failure were measured.

Results

Specimen stiffness was similar between groups. The mean load to repair failure was 123 ± 17 N in group 1, 114 ± 11 N in group 2, and 95 ± 13 N in group 3. The mean load to ultimate failure was 163 ± 15 N, 161 ± 12 N, and 145 ± 12 N, respectively. Although the repair failure loads of groups 1 and 2 were 29% and 17%, respectively, greater than the tack group, the differences were not statistically significant (P> .05). All ultimate failures occurred at the labral-implant interface.

Conclusion

Initial fixation strength of tissue tack and suture anchor repairs of SLAP lesions are comparable.
Tibiofemoral Kinematics of the Anterior Cruciate Ligament (ACL)-Deficient Weightbearing, Living Knee Employing Vertical Access Open “Interventional” Multiple Resonance Imaging
Authors: Logan Martin , Dunstan Edward , Robinson James , Williams Andrew , Gedroyc Wady , Freeman Michael
Published: March 2004

Background

Our current understanding of tibiofemoral kinematics in the anterior cruciate ligament (ACL)-deficient knee is very limited. Using vertical open-access MRI, it is possible to accurately analyze tibiofemoral motion in patients with isolated rupture of the ACL.

Study

Prospective cohort study.

Purpose

To assess if ACL rupture alters normal knee weightbearing kinematics.

Methods

Tibiofemoral motion was assessed through the arc of flexion from 0 ° to 90 ° in 10 patients with isolated rupture of the ACL in one knee and a normal contralateral knee. Midmedial and midlateral sagittal images were analyzed in all positions of flexion in both knees to assess the tibiofemoral relationship.

Results

In the lateral compartment of the knee, the tibial plateau is persistently subluxed anteriorly throughout the arc of flexion from 0 ° to 90 ° (flexion facet center to posterior tibial cortex distance of 15.8 mm ± 2.9 in ACL-deficient knees compared to 21.4 mm ± 1.4 in normal knees at 0 ° extension, P< .0001) when compared to normal knees. The medial tibiofemoral relationship is unchanged compared to normal knees.

Conclusion

Rupture of the ACL changes tibiofemoral kinematics producing anterior subluxation of the lateral tibial plateau.

Clinical Significance

Altered kinematics may explain, at least in part, the increased incidence of secondary osteoarthritis in patients with ACL rupture.
The Incidence and Risk Factors in the Development of Medial Tibial Stress Syndrome among Naval Recruits
Authors: Yates Ben , White Shaun
Published: March 2004

Purpose

To identify the incidence of medial tibial stress syndrome (MTSS) in a group of naval recruits undergoing a 10-week basic training period and to determine potential risk factors.

Method

One hundred and twenty-four recruits (84 men and 40 women) were followed prospectively during basic training. Anthropometric and lower limb biomechanical data were recorded at the start of the program along with injury history and previous sporting activity for the 3 months prior to enlisting. Recruits were monitored during training for development of medial tibial strees syndrome and were asked to complete an exit interview at the end of the program.

Results

Forty recruits (22 men and 18 women) developed medial tibial stress syndrome, giving an incidence of 35%. A significant relationship existed between gender and medial tibial stress syndrome (P= .012), with female recruits more likely to develop medial tibial stress syndrome than male recruits (53% vs 28%). A risk estimate revealed a relative risk of 2.03. The biomechanical results indicated a more pronated foot type (P= .002) in the medial tibial stress syndrome group when compared to the control group. A risk estimate established that recruits with a more pronated foot type had a relative risk of 1.70.

Conclusion

Identifying a pronated foot type prior to training may help reduce the incidence of medial tibial stress syndrome by early intervention to control abnormal pronation. Findings of a higher incidence of medial tibial stress syndrome among female recruits require further investigation.
Temperature Requirements for Altering the Morphology of Osteoarthritic and Nonarthritic Articular Cartilage
Authors: Kaplan Lee D. , Ionescu Dan , Ernsthausen John M. , Bradley James P. , Fu Freddie H. , Farkas Daniel L.
Published: March 2004

Background

Radiofrequency and laser thermal chondroplasty procedures are performed to debride and smooth fibrillated, articular cartilage.

Hypothesis

Temperature requirements necessary to achieve morphological change will be lower in fibrillated arthritic cartilage as compared with nonarthritic articular cartilage.

Study Design

Controlled laboratory study.

Methods

A thermal cell-culture chamber was mounted on a stereoscopic microscope and coordinated with a custom temperature-control program. Nonarthritic and osteoarthritic articular cartilage specimens were sectioned into full-thickness slices. The articular sections were exposed to temperatures incrementally from 37°C to 75°C. Real-time, digital capture microscopy was used to visualize and analyze the morphological changes undergone by the articular cartilage specimens.

Results

Arthritic articular cartilage displayed morphological change at 56.5 ± 1.7°C. Loss of fibrillation was the initial morphological change visualized. Continued thermal exposure caused a shrinkage effect of the entire tissue section that was similar to the change seen in nonarthritic sections. Nonarthritic cartilage displayed morphological change at 60.9 ± 1.9°C.

Conclusions

Consistent characteristic morphological changes were found at distinct temperatures in osteoarthritic and nonarthritic articular cartilage.

Clinical Relevance

This information begins to establish the thermal parameters required for morphological change of osteoarthritic articular cartilage.
Kinematic MRI Assessment of McConnell Taping before and after Exercise
Authors: Pfeiffer Ronald P. , DeBeliso Mark , Shea Kevin G. , Kelley Lorrie , Irmischer Bobbie , Harris Chad
Published: March 2004

Background

The authors assessed the effectiveness of McConnell medial glide taping after exercise using an MRI extremity scanner.

Hypothesis

McConnell taping would not be effective in maintaining medial glide of the patella after exercise.

Methods

Eighteen healthy women (mean age 22.28 ± 2.02 years) participated in the study. The patellofemoral joint was imaged at 4 knee flexion angles (0°, 12°, 24°, and 36°) in 3 conditions (no tape, with McConnell taping–medial glide, and with tape after exercise). Effectiveness was determined by measuring lateral patellar displacement. ANOVA and post hoc paired ttests were used to test for changes in lateral patellar displacement at each knee angle and condition.

Results

Statistical analysis revealed significant differences in lateral patellar displacement at all test angles, between the tape and no tape and between tape and tape after exercise conditions.

Conclusions

McConnell medial glide taping resulted in significant medial glide of the patellofemoral joint at all 4 knee angles before but not after exercise. However, McConnell medial glide taping may be effective under controlled rehabilitation conditions in which exercise is less intense.

Clinical Relevance

Beneficial effects of McConnell medial glide taping may be related to factors other than altered patellar alignment.
Automated External Defibrillators in National Collegiate Athletic Association Division I Athletics
Authors: Coris Eric E. , Sahebzamani Frances , Walz Steve , Ramirez Arnold M.
Published: March 2004

Background

Sudden cardiac death is the leading cause of death in athletes. Evidence on current sudden cardiac death prevention through preparticipation history, physicals, and noninvasive cardiovascular diagnostics has demonstrated a low sensitivity for detection of athletes at high risk of sudden cardiac death. Data are lacking on automated external defibrillator programs specifically initiated to respond to rare dysrhythmia in younger, relatively low-risk populations.

Methods

Surveys were mailed to the head athletic trainers of all National Collegiate Athletic Association Division I athletics programs listed in the National Athletic Trainers’ Association directory. In all, 303 surveys were mailed; 186 departments (61%) responded.

Results

Seventy-two percent (133) of responding National Collegiate Athletic Association Division I athletics programs have access to automated external defibrillator units; 54% (101) own their units. Proven medical benefit (55%), concern for liability (51%), and affordability (29%) ranked highest in frequency of reasons for automated external defibrillator purchase. Unit cost (odds ratio = 1.01; 95% confidence interval, 1.01-1.0), donated units (odds ratio = 1.92; confidence interval, 3.66-1.01), institution size (odds ratio = .0001; confidence interval, 1.3 E-4 to 2.2E-05), and proven medical benefit of automated external defibrillators (odds ratio = 24; confidence interval, 72-8.1) were the most significant predictors of departmental defibrillator ownership. Emergency medical service response time and sudden cardiac death event history were not significantly predictive of departmental defibrillator ownership. The majority of automated external defibrillator interventions occurred on nonathletes.

Conclusions

Many athletics medicine programs are obtaining automated external defibrillators without apparent criteria for determination of need. Usage and maintenance policies vary widely among departments with unit ownership or access. Programs need to approach the issue of unit acquisition and implementation with knowledge of the surrounding emergency medical service system, geography of their individual sports medicine facilities, numbers and relative risk of their athletes, and budgetary constraints.
Repetitive Low-Energy Shock Wave Treatment for Chronic Lateral Epicondylitis in Tennis Players
Authors: Rompe Jan D. , Decking Jens , Schoellner Carsten , Theis Christoph
Published: March 2004

Background

There is conflicting evidence regarding extracorporeal shock wave treatment for chronic tennis elbow.

Hypothesis

Treatment with repetitive low-energy extracorporeal shock wave treatment is superior to repetitive placebo extracorporeal shock wave treatment.

Methods

Seventy-eight patients enrolled in a placebo-controlled trial. All patients were tennis players with recalcitrant MRIconfirmed tennis elbow of at least 12 months’ duration. Patients were randomly assigned to receive either active low-energy extracorporeal shock wave treatment given weekly for 3 weeks (treatment group 1) or an identical placebo extracorporeal shock wave treatment (sham group 2). Main outcome measure was pain during resisted wrist extension at 3 months; secondary measures were >50% reduction of pain andthe Upper Extremity Function Scale.

Results

At 3 months, there was a significantly higher improvement in pain during resisted wrist extension in group 1 than in group 2 (mean [SD] improvement, 3.5 [2.0] and 2.0 [1.9]; P= .001 for between-group difference of improvement) and in the Upper Extremity Function Scale (mean [SD] improvement, 23.4 [14.8] and 10.9 [14.9]; P< .001 for between-group difference of improvement). In the treatment group, 65% of patients achieved at least a 50% reduction of pain, compared with 28% of patients in the sham group (P= .001 for between-group difference).

Conclusion

Low-energy extracorporeal shock wave treatment as applied is superior to sham treatment for tennis elbow.
Does Immobilization after Radiofrequency-Induced Shrinkage Influence the Biomechanical Properties of Collagenous Tissue?
Authors: Pötzl Wolfgang , Heusner Till , Kümpers Philipp , Marquardt Björn , Steinbeck Jörn
Published: March 2004

Background

Despite widespread use of radiofrequency-induced shrinkage of collagenous tissue, there have been no animal studies on the effects of postoperative immobilization on the biomechanical behavior of shrunken tissue.

Purpose

To examine the role of postoperative immobilization after radiofrequency-induced shrinkage, with special emphasis on the biomechanical properties of shrunken collagenous tissue.

Study Design

Controlled laboratory study.

Methods

One patellar tendon of 66 New Zealand White rabbits was shrunk. Six rabbits were sacrificed immediately after surgery. Twenty rabbits were not immobilized, twenty were immobilized for 3 weeks, and twenty were immobilized for 6 weeks. The biomechanical parameters failure strength, stiffness, and relaxation were tested.

Results

Nine weeks after surgery, biomechanical parameters were still low compared to control tendons. Shrunken tendons did not reach levels of normal tissue at any time after surgery, regardless of whether the animals had been immobilized. According to time-related development, all biomechanical parameters had the lowest levels 3 weeks after surgery. Immobilized tendons demonstrated a better and faster recovery than nonimmobilized tendons compared to the immediate postoperative level.

Conclusion

Postoperative immobilization supports recovery of biomechanical properties after shrinkage. Despite immobilization, biomechanical properties of shrunken tissue did not completely reach levels of normal tissue.

Clinical Relevance

Careful rehabilitation is imperative after radiofrequency-induced shrinkage. This animal model supports an immobilization period of at least 6 weeks after surgery.
Mechanical Properties of Soft Tissue Femoral Fixation Devices for Anterior Cruciate Ligament Reconstruction
Authors: Ahmad Christopher S. , Gardner Thomas R. , Groh Megan , Arnouk Johnny , Levine William N.
Published: March 2004

Purpose

To evaluate femoral soft tissue fixation for anterior cruciate ligament reconstruction.

Hypothesis

Femoral fixation devices have different ultimate strengths and slippage under cyclic loading.

Study Design

Controlled laboratory study.

Methods

Thirty-three porcine femora were used to study interference screw (9), Endobutton (8), Rigidfix cross-pin (8), and Bio-Transfix cross-pin (8) fixation methods. Fixation slippage was evaluated under cyclical load from 50 N to 250 N using a materials testing machine. Ultimate load was determined with a single load to failure.

Results

Total graft slippage was greater (P< .001) for the Rigidfix (6.02 ± 2.12 mm) and the interference screw (5.44 ± 3.25 mm) compared to the Endobutton (1.75 ± 0.97 mm) and the Bio-Transfix (1.14 ± 0.53 mm). All techniques showed the greatest slippage during the first 100 cycles (Rigidfix 84%, Endobutton 70%, interference screw 56%, and Bio-Transfix 55%). The failure load for the interference screw technique (539 ± 114 N) was lower (P= .0008) than for the other 3 techniques (737 ± 140 N for Rigidfix, 746 ± 119 N for Bio-Transfix, and 864 ± 164 N for Endobutton).

Conclusions

The interference screw and the Rigidfix fixation demonstrated inferior fixation biomechanics compared to the Bio-Transfix and the Endobutton techniques.
Foam-Reinforced Elderly Human Tibia Approximates Young Human Tibia Better than Porcine Tibia
Authors: Bailey Shana B. , Grover Dustin M. , Howell Stephen M. , Hull Maury L.
Published: March 2004

Background

Because there is an insufficient supply of young human knees, an alternative is needed for evaluating anterior cruciate ligament reconstructions. The authors determined whether an elderly human tibia reinforced with foam is a better substitute for a young human tibia than a porcine tibia in this study of the tibial fixation of a soft tissue anterior cruciate ligament graft using 3 devices.

Hypothesis

A foam-reinforced elderly human tibia more closely approximates the performance of a young human tibia than a porcine tibia.

Study Design

Biomechanical study.

Methods

Failure mode, stiffness, yield, and slippage were determined for a double-looped tendon graft fixed with either an interference screw, WasherLoc, or tandem washers in young human tibiae, foam-reinforced tibiae from elderly humans, and porcine tibiae.

Results

The stiffness and yield of interference screw and WasherLoc fixation in foam-reinforced tibiae more closely approximate those in young human tibiae than in porcine tibiae. Slippage of all combinations of tibiae and fixation devices was similar.

Conclusions

A foam-reinforced human tibia more closely approximates the performance of a young human tibia than that of a porcine tibia in this study.

Clinical Relevance

Fixation devices should be tested in foam-reinforced tibiae from elderly humans rather than tibiae from large farm animals when the supply of young human knees is insufficient.
Biomechanical Comparison of Tibial Inlay versus Transtibial Techniques for Posterior Cruciate Ligament Reconstruction
Authors: Margheritini Fabrizio , Mauro Craig S. , Rihn Jeffrey A. , Stabile Kathryne J. , Woo Savio L-Y. , Harner Christopher D.
Published: March 2004

Background

The tibial inlay technique for posterior cruciate ligament reconstruction has been proposed to provide a more anatomic reconstruction because it eliminates the sharp turn in the graft as it exits the proximal margin of the tibial tunnel in the transtibial technique.

Hypothesis

Reconstruction of the posterior cruciate ligament using the tibial inlay technique would more closely restore intact knee kinematics and in situ forces in the posterior cruciate ligament than would reconstruction using the transtibial technique.

Methods

Ten human cadaveric knees were tested in a controlled laboratory study. A robotic/universal force-moment sensor testing system was used to apply a 134-N posterior tibial load at 5 knee flexion angles: 0°, 30°, 60°, 90°, and 120°. Four knee conditions were tested: intact, posterior cruciate ligament–deficient, and the single-bundle tibial inlay reconstruction and transtibial posterior cruciate ligament reconstruction.

Results

Both reconstruction techniques restored posterior tibial translations to 1.7 to 2.1 mm of the intact knee, with no statistical differences between the techniques. In response to the posterior tibial load, in situ forces in both grafts were between 7 and 39 N less than those in the intact posterior cruciate ligament, with no significant differences between the grafts.

Clinical Relevance

The study suggests that either technique may be performed with similar biomechanical results at initial fixation under these loading conditions.
Relationship between Radiographic Abnormalities of Lumbar Spine and Incidence of Low Back Pain in High School and College Football Players
Authors: Iwamoto Jun , Abe Hitoshi , Tsukimura Yasunori , Wakano Koichi
Published: March 2004

Background

Low back pain is a common presenting symptom among players of American football. In Japan, however, skeletal disorders in football players, including low back problems, have been rarely studied, and management to prevent skeletal disorders has not been established.

Study Design

An epidemiological study with prospective observation.

Methods

The authors analyzed the relationship between lumbar spine abnormalities viewed through radiographs taken during the preparticipation physical examination, and the incidence of low back pain during a 1-year period in 171 high school and 742 college football players. Abnormalities assessed were spondylolysis, disc space narrowing, spinal instability, Schmorl's node, balloon disc, and spina bifida occulta.

Results

High school players with spondylolysis had a higher incidence of low back pain (79.8%) than those with no abnormal radiographic results (37.1%). College players with spondylolysis, disc space narrowing, and spinal instability had a higher incidence of low back pain (80.5%, 59.8%, and 53.5%, respectively) than those with no abnormal radiographs (32.1%), and college players with spondylolysis had a higher incidence of low back pain than those with disc space narrowing and spinal instability.

Conclusions

The results of the present study suggest that an abnormality such as spondylolysis is the most significant risk factor for low back pain in high school and college football players, and that disc space narrowing and spinal instability are also significant risk factors for low back pain in athletes with greater athletic activity such as college football players.