WorldWideScience

Sample records for fidelis lead fracture

  1. Medtronic Sprint Fidelis lead recall: determining the initial 5-year management cost to Medicare.

    Science.gov (United States)

    Mehrotra, Amit K; Knight, Bradley P; Smelley, Matthew P; Shah, Dipak P; Weisberg, Ian; Baez-Escudero, Jose; Beshai, John F; Burke, Martin C

    2011-08-01

    The Medtronic Sprint Fidelis defibrillator lead has a high failure rate and was recalled in October 2007. The purpose of this study was to determine the incremental cost of the management of this lead to Medicare. Real hospital cost data in U.S. dollars were collected on 32 patients with a Medtronic Sprint Fidelis lead who underwent lead revision. Of these patients, 15 were excluded because they had insurance coverage other than that provided by the Centers for Medicare & Medicaid Services. Seventeen patients with Medicare or Medicaid coverage underwent lead revision either electively (n = 6) or after being hospitalized for multiple shocks caused by a lead fracture (n = 11). Eighty-eight percent of the patients underwent extraction of the Fidelis lead at the time of lead revision. A decision model was made that outlines the potential management of the lead recall over time. The existing literature and Medtronic data were reviewed for parameters included in the decision model. The model assumed that 175,000 patients were alive with an implanted Fidelis lead at the time of the recall and that the annual failure rate will be 1.8% over the first 5 years. It was also assumed that 1% of patients without a lead fracture would also undergo elective lead revision each year and that the proportion of patients who would have the Fidelis lead extracted rather than abandoned would be 20:80. Estimates with ranges were used for parameters for which no data are available. The industry standard rate of lead failure was estimated based on the Sprint Quattro model 6947 lead, and this was subtracted from the estimated rates for the Sprint Fidelis lead such that the incremental cost of the lead failure could be estimated. The cost of lead revision trended higher when the Fidelis lead was extracted rather than abandoned ($45,077 ± $11,693 vs $33,802 ± $33, P = .20). In 5 years, the estimated cost impact of the Medtronic Sprint Fidelis lead recall to Medicare will be $287

  2. The Medtronic Sprint Fidelis Lead Advisory Notification has no adverse impact on patient reported outcomes in Danish implantable cardioverter defibrillator patients

    DEFF Research Database (Denmark)

    Pedersen, Susanne Møller; Versteeg, Henneke; Nielsen, Jens C.

    The Medtronic Sprint Fidelis Lead Advisory Notification has no adverse impact on patient reported outcomes in Danish implantable cardioverter defibrillator patients.......The Medtronic Sprint Fidelis Lead Advisory Notification has no adverse impact on patient reported outcomes in Danish implantable cardioverter defibrillator patients....

  3. The Medtronic Sprint Fidelis Lead Advisory Notification Has No Adverse Impact on Patient Reported Outcomes in Danish Implantable Cardioverter Defibrillator Patients

    DEFF Research Database (Denmark)

    Pedersen, Susanne Møller; Versteeg, Henneke; Nielsen, Jens C.

    The Medtronic Sprint Fidelis Lead Advisory Notification Has No Adverse Impact on Patient Reported Outcomes in Danish Implantable Cardioverter Defibrillator Patients.......The Medtronic Sprint Fidelis Lead Advisory Notification Has No Adverse Impact on Patient Reported Outcomes in Danish Implantable Cardioverter Defibrillator Patients....

  4. Metatarsal fracture leading to massive pulmonary embolism

    Directory of Open Access Journals (Sweden)

    Vikas Rajpurohit

    2017-01-01

    Full Text Available Immobilization and bed rest after fracture and orthopedic surgery are routinely advised protocol. Period of bed rest usually depends on the type of injury and orthopedic procedure, ranging from few days to weeks. The trauma, surgery, and immobilization with other contributing factors can lead to deep vein thrombosis and pulmonary embolism (PE in these patients. Although there is high incidence of PE in such patients, it is difficult to diagnose, primarily because of the variety of nonspecific signs and symptoms. Here, we discuss a case of a 30-year-old female, who had suffered a trivial roadside accident leading to metatarsal bone fracture and later on presented in emergency with seizures, pulmonary edema, and cardiac arrest, after immobilization of just 5 days which was diagnosed to be result of massive PE. Here, we will discuss the pathophysiology, risk factors, and management of massive PE.

  5. Patient-reported outcomes in Danish implantable cardioverter defibrillator patients with a Sprint Fidelis lead advisory notification

    DEFF Research Database (Denmark)

    Pedersen, Susanne S; Versteeg, Henneke; Nielsen, Jens Cosedis;

    2011-01-01

    Few studies have investigated the association between implantable cardioverter defibrillators (ICDs) and lead advisory notifications and patient-reported outcomes (PROs). We examined (i) whether the mode used to inform patients about a device advisory is associated with PROs, and (ii) whether pat...

  6. The influence of lead length on the fractures associated with leading corners and sidings

    CSIR Research Space (South Africa)

    Turner, PA

    1989-02-01

    Full Text Available Stopes on three reef horizons and at various depths were examined in the vicinity of inter-panel leads. The general geometry of fractures in the vicinity of inter-panels leads is outlined. The extend of fracturing parallel to the siding between...

  7. Pacemaker lead fracture without an increase in lead impedance caused by cardiac fibroma

    Directory of Open Access Journals (Sweden)

    Daisuke Sato

    2013-12-01

    Full Text Available We report the case of a 64-year-old man who had a permanent pacemaker with a unipolar silicone electrode positioned in the right ventricle in 1989 for sinus node dysfunction. On a routine checkup in June 2011, a 28-mm-diameter mass was discovered, which appeared to adhere to the tricuspid valve and the ventricular lead. The size of the mass did not change for the next 6 months, and the lead impedance was maintained at around 500–600 Ω. Because pacing failure was observed in January 2012, he underwent an urgent pacemaker check; however, the lead impedance was found not to have increased greatly (689 Ω. Nevertheless, the pacemaker lead was noted to be fractured at the tricuspid level. His echocardiogram showed new severe tricuspid regurgitation and a floating mass around the lead. We extracted the fractured lead, enucleated the tumor, replaced the tricuspid valve, and placed an epicardial lead. Macroscopic examination revealed that the tumor surrounded the fractured lead and covered the stump. Pathological examination revealed that the tumor was composed of fibrous connective tissue. We presumed that electric current continued to flow through the stump of the fractured unipolar lead to the generator, and this might have caused the limited increase in lead impedance.

  8. Lead Fractures in Deep Brain Stimulation during Long-Term Follow-Up

    Directory of Open Access Journals (Sweden)

    Fernando Seijo Fernández

    2010-01-01

    Full Text Available The purpose was to determine the incidence of lead fracture in patients with DBS over a long period of time. We present a retrospective study of 208 patients who received 387 DBS electrodes. Fourteen patients had sixteen lead fractures (4% of the implanted leads and two patients suffered from 2 lead fractures. Of all lead fractures, five patients had the connection between the leads and the extension cables located in mastoids region, ten in cervical area and one in thoracic region. The mean distance from the connection between the electrode and the extension cable and the lead fracture was 10.7 mm. The lead fracture is a common, although long-term complication in DBS surgery. In our experience, the most common site of electrode cable breakage is approximately between 9 and 13 mm from the junction between the lead and the extension cable. The most important cause of lead fracture is the rotational movement of the lead-extension cable system. If we suspect lead fracture, we must check the impedance of the electrode and to evaluate the side effects of voltage. Finally, we must conduct a radiological screening.

  9. Pregnancy Associated Osteoporosis Leading to Vertebral Compression Fracture

    Directory of Open Access Journals (Sweden)

    Berke Aras

    2016-08-01

    Full Text Available To describe a patient with low back pain developed in the postpartum period and diagnosed as having vertebral compression fracture due to pregnancy and lactation associated osteoporosis. A 28-year old woman presented with complaints of low back pain started two months after her first delivery. Laboratory tests including bone mineral density (BMD, biochemical evaluation and lomber spinal magnetic resonance imaging (MRI was evaluated. Lomber spine BMD was extremely decreased: L2-4: 0,685 g/cm2, T-score -3.9, Z-score -3.9. MRI revealed a compression fracture of T12 vertebra. The patient was investigated in terms of all possible risk factors and hormonal pathology causing osteoporosis and no abnormality was found. So she was diagnosed as having pregnancy and associated osteoporosis. Cease of the lactation and the treatment with teriparatide were recommended to the patient but she refused both of them. Clinicians should take into account of pregnancy and lactation associated osteoporosis, when evaluating patients with low back pain in early postpartum period.

  10. Fracture mechanics analyses of the slip-side joggle regions of wing-leading-edge panels

    Directory of Open Access Journals (Sweden)

    Kyongchan Song

    2011-01-01

    Full Text Available The Space Shuttle wing-leading edge consists of panels that are made of reinforced carbon-carbon. Coating spallation was observed near the slip-side region of the panels that experience extreme heating. To understand this phenomenon, a root-cause investigation was conducted. As part of that investigation, fracture mechanics analyses of the slip-side joggle regions of the hot panels were conducted. This paper presents an overview of the fracture mechanics analyses.

  11. Fracture Mechanics Analyses of the Slip-Side Joggle Regions of Wing-Leading-Edge Panels

    Science.gov (United States)

    Raju, Ivatury S.; Knight, Norman F., Jr.; Song, Kyongchan; Phillips, Dawn R.

    2011-01-01

    The Space Shuttle wing-leading edge consists of panels that are made of reinforced carbon-carbon. Coating spallation was observed near the slip-side region of the panels that experience extreme heating. To understand this phenomenon, a root-cause investigation was conducted. As part of that investigation, fracture mechanics analyses of the slip-side joggle regions of the hot panels were conducted. This paper presents an overview of the fracture mechanics analyses.

  12. Permanent pacing system malfunction due to hidden adjacent fractures of atrial and ventricular leads.

    Science.gov (United States)

    Wang, L; Davis, M J

    1997-03-01

    Periods of failure of ventricular pacing and atrial sensing were discovered on Holter recording in a 10-year-old boy 4 years after the implantation of a dual-chamber pacemaker with endocardial bipolar leads brought out through the right atrial wall. The old generator was explanted and the old leads tested. There was considerable atrial oversensing of an electrical artefact. The pacing threshold of ventricular lead was 1.8 V compared with 0.3 V 6 days post implantation. Post-operative lateral chest X-ray disclosed fractures of both atrial and ventricular leads at the approximate site of exit from the right atriotomy. Review of the preoperative lateral film showed that the fractures had been hidden by an ECG electrode.

  13. Review of the mechanical and fracture behavior of perovskite lead-free ferroelectrics for actuator applications

    Science.gov (United States)

    Webber, Kyle G.; Vögler, Malte; Khansur, Neamul H.; Kaeswurm, Barbara; Daniels, John E.; Schader, Florian H.

    2017-06-01

    There has been considerable progress in the development of large strain lead-free perovskite ferroelectrics over the past decade. Under certain conditions, the electromechanical properties of some compositions now match or even surpass commercially available lead-containing materials over a wide temperature range, making them potentially attractive for non-resonant displacement applications. However, the phenomena responsible for the large unipolar strains and piezoelectric responses can be markedly different to classical ferroelectrics such as Pb(Zr,Ti)O3 and BaTiO3. Despite the promising electromechanical properties, there is little understanding of the mechanical properties and fracture behavior, which is crucial for their implementation into applications where they will be exposed to large electrical, mechanical, and thermal fields. This work discusses and reviews the current understanding of the mechanical behavior of large-strain perovskite lead-free ferroelectrics for use in actuators and provides recommendations for further work in this important field.

  14. Fracture Mechanics Analyses of Reinforced Carbon-Carbon Wing-Leading-Edge Panels

    Science.gov (United States)

    Raju, Ivatury S.; Phillips, Dawn R.; Knight, Norman F., Jr.; Song, Kyongchan

    2010-01-01

    Fracture mechanics analyses of subsurface defects within the joggle regions of the Space Shuttle wing-leading-edge RCC panels are performed. A 2D plane strain idealized joggle finite element model is developed to study the fracture behavior of the panels for three distinct loading conditions - lift-off and ascent, on-orbit, and entry. For lift-off and ascent, an estimated bounding aerodynamic pressure load is used for the analyses, while for on-orbit and entry, thermo-mechanical analyses are performed using the extreme cold and hot temperatures experienced by the panels. In addition, a best estimate for the material stress-free temperature is used in the thermo-mechanical analyses. In the finite element models, the substrate and coating are modeled separately as two distinct materials. Subsurface defects are introduced at the coating-substrate interface and within the substrate. The objective of the fracture mechanics analyses is to evaluate the defect driving forces, which are characterized by the strain energy release rates, and determine if defects can become unstable for each of the loading conditions.

  15. Validation Test Report for the Arctic Cap Nowcast/Forecast System as a Fractures/Leads and Polynyas Product

    Science.gov (United States)

    2015-05-26

    provides nowcasts and forecasts of the global ocean environment which includes three-dimensional ocean temperature , salinity and current structure...and March 20th created instabilities in the wind-driven ice floes on the Arctic Ocean which led to multiple fractures in the ice near the camp...Test Report for the Arctic Cap Nowcast/Forecast System as a Fractures/Leads and Polynyas Product Julia W. Crout Vencore Services and Solutions, Inc

  16. Prone position in balloon kyphoplasty leads to no secondary vertebral compression fractures in osteoporotic spine – a MRI study

    Directory of Open Access Journals (Sweden)

    Spalteholz, Matthias

    2014-12-01

    Full Text Available Purpose: Vertebral compression fractures are the most common fractures in the elderly. Long lasting pain and deformity is responsible for consecutive impairment with markedly reduced life quality, increased morbidity and mortality. The beneficial effects of balloon kyphoplasty are verified in many studies. Subsequent fracture risk is not finally clarified, cement related risks and deformity related risks are discussed. There is less knowledge about the risk of bone marrow edema and new fractures during balloon kyphoplasty procedure. The goal of this study is to examine, if prone position during kyphoplasty is an independent risk factor for new fractures in the osteoporotic spine. Methods: Consecutive MRI study of 20 patients with fresh, non-traumatic thoracolumbar vertebral compression fractures and balloon kyphoplasty treatment. MRI Scans of the thoracolumbar spine were obtained after surgery, before patients have been mobilized. Specific MRI changes like new bone marrow edema, signal intensity changes in adjacent and remote segments and new fractures were assessed by specialized neuro-radiologist. Results: 20 MR images were examined within 48 hours after balloon kyphoplasty procedure. 85% did not show bone marrow edema extent changes after kyphoplasty. We found minor increase of bone marrow edema within the augmented vertebral body in 3 cases. We did not find any new bone marrow edema and no new fractures in adjacent and remote segments after balloon kyphoplasty treatment.Conclusion: Prone position leads to no new bone marrow edema and no new fractures in the osteoporotic spine. Accordingly, prone position has no risk for adjacent level fractures in osteoporotic spines.

  17. 7 CFR 27.93 - Bona fide spot markets.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Bona fide spot markets. 27.93 Section 27.93... REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Spot Markets § 27.93 Bona fide spot markets. The following markets have been determined, after investigation, and are...

  18. Do cadmium, lead, and aluminum in drinking water increase the risk of hip fractures? A NOREPOS study.

    Science.gov (United States)

    Dahl, Cecilie; Søgaard, Anne Johanne; Tell, Grethe S; Flaten, Trond Peder; Hongve, Dag; Omsland, Tone Kristin; Holvik, Kristin; Meyer, Haakon E; Aamodt, Geir

    2014-01-01

    The aim of this study was to investigate relations between cadmium, lead, and aluminum in municipality drinking water and the incidence of hip fractures in the Norwegian population. A trace metals survey in 566 waterworks was linked geographically to hip fractures from hospitals throughout the country (1994-2000). In all those supplied from these waterworks, 5,438 men and 13,629 women aged 50-85 years suffered a hip fracture. Poisson regression models were fitted, adjusting for age, region of residence, urbanization, and type of water source as well as other possibly bone-related water quality factors. Effect modification by background variables and interactions between water quality factors were examined (correcting for false discovery rate). Men exposed to a relatively high concentration of cadmium (IRR = 1.10; 95 % CI 1.01, 1.20) had an increased risk of fracture. The association between relatively high lead and hip fracture risk was significant in the oldest age group (66-85 years) for both men (IRR = 1.11; 95 % CI 1.02, 1.21) and women (IRR = 1.10; 95 % CI 1.04, 1.16). Effect modification by degree of urbanization on hip fracture risk in men was also found for all three metals: cadmium, lead, and aluminum. In summary, a relatively high concentration of cadmium, lead, and aluminum measured in drinking water increased the risk of hip fractures, but the associations depended on gender, age, and urbanization degree. This study could help in elucidating the complex effects on bone health by risk factors found in the environment.

  19. Fracture Mechanics Analyses of the Slip-Side Joggle Regions of Wing-Leading Edge Panels

    Science.gov (United States)

    Raju, Ivatury S.; Knight, Norman F., Jr.; Song, Kyongchan; Phillips, Dawn R.

    2010-01-01

    The Space Shuttle Orbiter wing comprises of 22 leading edge panels on each side of the wing. These panels are part of the thermal protection system that protects the Orbiter wings from extreme heating that take place on the reentry in to the earth atmosphere. On some panels that experience extreme heating, liberation of silicon carbon (SiC) coating was observed on the slip side regions of the panels. Global structural and local fracture mechanics analyses were performed on these panels as a part of the root cause investigation of this coating liberation anomaly. The wing-leading-edge reinforced carbon-carbon (RCC) panels, Panel 9, T-seal 10, and Panel 10, are shown in Figure 1 and the progression of the stress analysis models is presented in Figure 2. The global structural analyses showed minimal interaction between adjacent panels and the T-seal that bridges the gap between the panels. A bounding uniform temperature is applied to a representative panel and the resulting stress distribution is examined. For this loading condition, the interlaminar normal stresses showed negligible variation in the chord direction and increased values in the vicinity of the slip-side joggle shoulder. As such, a representative span wise slice on the panel can be taken and the cross section can be analyzed using plane strain analysis.

  20. Reconstruction of the Terminal of an Abandoned Fractured Unipolar Coronary Sinus Lead: a Feasible Solution to Restore Effective Cardiac Resynchronization Therapy

    Directory of Open Access Journals (Sweden)

    Armando Gardini, MD

    2013-05-01

    Full Text Available Complications related to coronary sinus lead are not infrequent in recipients of cardiac resynchronization devices. We describe the case of a patient with a biventricular implantable cardioverter defibrillator with persistent phrenic nerve stimulation, previous coronary sinus lead fracture, and severe left subclavian vein stenosis. The reimplantation of a new coronary sinus lead on the left side, ipsilateral to the original implant, was unsuccessful. In order to avoid more complex and risky procedures, we performed the repair of the fractured abandoned lead with the reconstruction of the unipolar lead terminal. Effective biventricular pacing was obtained with satisfactory electrical parameters and it was maintained at twelve months follow-up.

  1. Fracture in a Young Male Patient Leading to the Diagnosis of Wilson's Disease: A Case Report.

    Science.gov (United States)

    Shin, John Junghun; Lee, Jun-Pyo; Rah, Jung-Ho

    2015-02-01

    Wilson's disease is a rare genetic disorder that has abnormal copper metabolism. Although the disease's main problems are found in liver and brain, some studies revealed manifestation of various musculoskeletal problems in the patients. In this report, we encountered a young patient who had fracture in the forearm bone. Initially, exception to a previous history of fracture from a motorcycle accident, the patient did not have any medical or drug use history, and laboratory work-ups were insignificant. However, with suspicion on his bone's integrity, bone densitometry was recommended and revealed osteopenic change. To disclose a cause for the change, questions were made to recall any particular history or event, and his complaint of recent vision loss led to ophthalmologic consultation where under slit-lamp test found Kayser-Fleischer ring. Further laboratory work-up found low levels of serum copper and ceruloplasmin and high copper level in 24-hr urine sample that led to the diagnosis of Wilson's disease. Although Wilson's disease has been frequently noticed with considerable musculoskeletal manifestation, it rarity makes the diagnosis illusive to a physician. Hence, despite of its rarity, it is imperative to remember the disease's bony manifestation, and it should be suspected in young patients with demineralized bone when the reason for brittle bone cannot be answered with other better known conditions.

  2. Dynamic fracturing by successive coseismic loadings leads to pulverization in active fault zones

    Science.gov (United States)

    Aben, F. M.; Doan, M.-L.; Mitchell, T. M.; Toussaint, R.; Reuschlé, T.; Fondriest, M.; Gratier, J.-P.; Renard, F.

    2016-04-01

    Previous studies show that pulverized rocks observed along large faults can be created by single high-strain rate loadings in the laboratory, provided that the strain rate is higher than a certain pulverization threshold. Such loadings are analogous to large seismic events. In reality, pulverized rocks have been subject to numerous seismic events rather than one single event. Therefore, the effect of successive "milder" high-strain rate loadings on the pulverization threshold is investigated by applying loading conditions below the initial pulverization threshold. Single and successive loading experiments were performed on quartz-monzonite using a Split Hopkinson Pressure Bar apparatus. Damage-dependent petrophysical properties and elastic moduli were monitored by applying incremental strains. Furthermore, it is shown that the pulverization threshold can be reduced by successive "milder" dynamic loadings from strain rates of ~180 s-1 to ~90 s-1. To do so, it is imperative that the rock experiences dynamic fracturing during the successive loadings prior to pulverization. Combined with loading conditions during an earthquake rupture event, the following generalized fault damage zone structure perpendicular to the fault will develop: furthest from the fault plane, there is a stationary outer boundary that bounds a zone of dynamically fractured rocks. Closer to the fault, a pulverization boundary delimits a band of pulverized rock. Consecutive seismic events will cause progressive broadening of the band of pulverized rocks, eventually creating a wider damage zone observed in mature faults.

  3. 29 CFR 1604.2 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Sex as a bona fide occupational qualification. 1604.2... GUIDELINES ON DISCRIMINATION BECAUSE OF SEX § 1604.2 Sex as a bona fide occupational qualification. (a) The commission believes that the bona fide occupational qualification exception as to sex should be...

  4. DMPD: NOD-like receptors (NLRs): bona fide intracellular microbial sensors. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18585455 NOD-like receptors (NLRs): bona fide intracellular microbial sensors. Shaw...tml) (.csml) Show NOD-like receptors (NLRs): bona fide intracellular microbial sensors. PubmedID 18585455 Ti...tle NOD-like receptors (NLRs): bona fide intracellular microbial sensors. Authors

  5. Lead

    Science.gov (United States)

    ... found? Who is at risk? What are the health effects of lead? Get educational material about lead Get certified as a Lead Abatement Worker, or other abatement discipline Lead in drinking water Lead air pollution Test your child Check and maintain your home ...

  6. A cost-effectiveness analysis of a proactive management strategy for the Sprint Fidelis recall: a probabilistic decision analysis model.

    Science.gov (United States)

    Bashir, Jamil; Cowan, Simone; Raymakers, Adam; Yamashita, Michael; Danter, Matthew; Krahn, Andrew; Lynd, Larry D

    2013-12-01

    The management of the recall is complicated by the competing risks of lead failure and complications that can occur with lead revision. Many of these patients are currently undergoing an elective generator change--an ideal time to consider lead revision. To determine the cost-effectiveness of a proactive management strategy for the Sprint Fidelis recall. We obtained detailed clinical outcomes and costing data from a retrospective analysis of 341 patients who received the Sprint Fidelis lead in British Columbia, where patients younger than 60 years were offered lead extraction when undergoing generator replacement. These population-based data were used to construct and populate a probabilistic Markov model in which a proactive management strategy was compared to a conservative strategy to determine the incremental cost per lead failure avoided. In our population, elective lead revisions were half the cost of emergent revisions and had a lower complication rate. In the model, the incremental cost-effectiveness ratio of proactive lead revision versus a recommended monitoring strategy was $12,779 per lead failure avoided. The proactive strategy resulted in 21 fewer failures per 100 patients treated and reduced the chance of an additional complication from an unexpected surgery. Cost-effectiveness analysis suggests that prospective lead revision should be considered when patients with a Sprint Fidelis lead present for pulse generator change. Elective revision of the lead is justified even when 25% of the population is operated on per year, and in some scenarios, it is both less costly and provides a better outcome. © 2013 Heart Rhythm Society Published by Heart Rhythm Society All rights reserved.

  7. Thoracolumbar spine fractures in the geriatric fracture center : early ambulation leads to good results on short term and is a successful and safe alternative compared to immobilization in elderly patients with two-column vertebral fractures

    NARCIS (Netherlands)

    Weerink, L B M; Folbert, E C; Kraai, M; Smit, R S; Hegeman, J H; van der Velde, D

    2014-01-01

    INTRODUCTION: Thoracolumbar spine fractures are common osteoporotic fractures among elderly patients. Several studies suggest that these fractures can be treated successfully with a nonoperative management. The aim of this study is to evaluate the conservative treatment of elderly patients with a ve

  8. Lead

    Science.gov (United States)

    ... Chapter 6 Chapter 7 Chapter 8 Chapter 9 Appendix I Appendix II Tables Figures State Programs Alabama Alaska Arizona ... Tool Kit Resources Healthy Homes and Lead Poisoning Prevention Training Center (HHLPPTC) Training Tracks File Formats Help: ...

  9. Semper Fidelis: Values of The Marine Retiree Group

    Directory of Open Access Journals (Sweden)

    Virienia Puspita

    2016-01-01

    the group through the method of analysis of fantasy by Bormann. The results of the this study indicate the stories of Marine retiree in Depok are the bridge of experience of Marine retiree in the past with present time. Besides that, it is the formation of behavior in forms of values, culture and communication behavior of them. From the analysis theme shows that the group values of Marine retiree in Depok has manifested by universal's idealism value of Marines Semper Fidelis (loyalty, sacrifice, dedication, pride and self esteem. The group rhetorical visions are pride of the group, desire for being accepted and close to their group's identity.

  10. A missed injury leading to delayed diagnosis and postoperative infection of an unstable thoracic spine fracture - case report of a potentially preventable complication

    Directory of Open Access Journals (Sweden)

    Stahel Philip F

    2011-10-01

    Full Text Available Abstract Background Patients suffering from polytrauma often present with altered mental status and have varying levels of examinability. This makes evaluation difficult. Physicians are often required to rely on advanced imaging techniques to make prompt and accurate diagnoses. Occasionally, injury detection on advanced imaging studies can be challenging given the subtle findings associated with certain conditions, such as diffuse idiopathic skeletal hyperostosis (DISH. Delayed or missed diagnoses in the setting of spinal fracture can lead to catastrophic neurological injury. Case presentation A man struck by a motor vehicle suffered multiple traumatic injuries including numerous rib fractures, a mechanically unstable pelvic fracture, and also had suspicion for an aortic injury. Unfortunately, the upper thoracic segment (T1-5 was only visualized with axial images based on the electronic data. Several days later, a contrast CT scan obtained to check the status of suspected aortic injury revealed T3-T4 subluxation indicative of an unstable extension-type fracture in the setting of DISH. Due to the missed injury and delay in diagnosis, surgery was not performed until eight days after the injury. At surgery, the patient was found to have left T3-T4 facet joint infection as well as infected hematoma surrounding a left T4 transverse process fracture and a traumatic T4 costo-transverse joint fracture-subluxation. Despite presence of infection, an instrumented posterior spinal fusion from T1-T6 was performed and the patient recovered well after antibiotic treatment. Conclusion A T3-T4 unstable DISH extension-type fracture was initially missed in a polytrauma patient due to inadequate imaging acquisition, which caused a delay in treatment and bacterial seeding of fracture hematoma. Complete imaging is especially needed in obtunded patients that cannot be thoroughly examined.

  11. 7 CFR 15a.61 - Sex as a bona-fide occupational qualification.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Sex as a bona-fide occupational qualification. 15a.61... RECEIVING OR BENEFITTING FROM FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs and Activities Prohibited § 15a.61 Sex as a bona-fide...

  12. Hertel 7 fracture of the humeral head. Can two different fixation systems (Diphos/PHP) lead to different outcomes? A retrospective study.

    Science.gov (United States)

    Gumina, S; Baudi, P; Candela, V; Campochiaro, G

    2016-10-01

    To compare clinical outcomes and complication rates in the medium-to-long-term follow-up of Hertel 7 humeral head fractures treated with two different locking plates. A total of 52 patients with type 7 humeral head fracture (in accordance with Hertel classification) were enrolled retrospectively: 24 patients [4 male, 20 female; mean age (standard deviation [SD]): 68.9 (5.8) years] were treated with Diphos H plate (Group A) and 28 patients [6 male, 22 female; mean age (SD): 61.0 (7.5) years] with Proximal Humeral Plate (PHP; Group B). The mean follow-up periods were 25.6 and 18.9 months, respectively. Functional outcomes were assessed using the Constant score and Disabilities of the Arm, Shoulder and Hand (DASH) score; X-ray evaluation was also performed and complications were recorded. The mean Constant score in the Diphos and PHP groups at follow-up were 75.6 (SD 13.4) and 78.9 (SD 12.8), respectively (p>0.05). The DASH score was similar in both groups (Diphos: 18.6, range 0-51.5; PHP: 16.8, range 0-47.8) (p>0.05). In our series, 9.6% of patients had complications; these included a case of aseptic non-union and a case of avascular necrosis of the humeral head in each group, and a secondary screw perforation in a patient treated with Diphos. In patients with Hertel 7 proximal humeral fractures, Diphos and PHP lead to similar satisfactory functional outcomes and are associated with low complication rates; this confirms that both are useful implants for the treatment of this pattern of fracture. Copyright © 2016. Published by Elsevier Ltd.

  13. Bona fide interaction-driven topological phase transition in correlated symmetry-protected topological states

    Science.gov (United States)

    He, Yuan-Yao; Wu, Han-Qing; You, Yi-Zhuang; Xu, Cenke; Meng, Zi Yang; Lu, Zhong-Yi

    2016-03-01

    It is expected that the interplay between nontrivial band topology and strong electron correlation will lead to very rich physics. Thus a controlled study of the competition between topology and correlation is of great interest. Here, employing large-scale quantum Monte Carlo simulations, we provide a concrete example of the Kane-Mele-Hubbard model on an AA-stacking bilayer honeycomb lattice with interlayer antiferromagnetic interaction. Our simulation identified several different phases: a quantum spin Hall insulator (QSH), an x y -plane antiferromagnetic Mott insulator, and an interlayer dimer-singlet insulator. Most importantly, a bona fide topological phase transition between the QSH and the dimer-singlet insulators, purely driven by the interlayer antiferromagnetic interaction, is found. At the transition, the spin and charge gap of the system close while the single-particle excitations remain gapped, which means that this transition has no mean-field analog and it can be viewed as a transition between bosonic symmetry-protected topological (SPT) states. At one special point, this transition is described by a (2 +1 )d O (4 ) nonlinear sigma model with exact S O (4 ) symmetry and a topological term at exactly Θ =π . The relevance of this work towards more general interacting SPT states is discussed.

  14. Bona fide interaction-driven topological phase transition in correlated SPT states

    Science.gov (United States)

    Meng, Zi Yang; He, Yuan-Yao; Wu, Han-Qing; You, Yi-Zhuang; Xu, Cenke; Lu, Zhong-Yi

    It is expected the interplay between non-trivial band topology and strong electron correlation will lead to very rich physics. Thus a controlled study of the competition between topology and correlation is of great interest. Here, employing large-scale quantum Monte Carlo simulations, we provide a concrete example of the Kane-Mele-Hubbard model on an AA stacking bilayer honeycomb lattice with inter-layer antiferromagnetic interaction. Our simulation identified several different phases: a quantum spin-Hall insulator (QSH), a xy-plane antiferromagnetic Mott insulator (xy-AFM) and an inter-layer dimer-singlet insulator (dimer-singlet). Most importantly, a bona fide topological phase transition between the QSH and the dimer-singlet insulators, purely driven by the inter-layer antiferromagnetic interaction is found. At the transition, the spin and charge gap of the system close while the single-particle excitations remain gapped, which means that this transition has no mean field analogue and it can be viewed as a transition between bosonic SPT states. At one special point, this transition is described by a (2+1)d O(4) nonlinear sigma model with exact SO(4) symmetry, and a topological term at theta=p. Relevance of this work towards more general interacting SPT states is discussed.

  15. Imaging of vertebral fractures

    Directory of Open Access Journals (Sweden)

    Ananya Panda

    2014-01-01

    Full Text Available Vertebral fracture is a common clinical problem. Osteoporosis is the leading cause of non-traumatic vertebral fracture. Often, vertebral fractures are not clinically suspected due to nonspecific presentation and are overlooked during routine interpretation of radiologic investigations. Moreover, once detected, many a times the radiologist fails to convey to the clinician in a meaningful way. Hence, vertebral fractures are a constant cause of morbidity and mortality. Presence of vertebral fracture increases the chance of fracture in another vertebra and also increases the risk of subsequent hip fracture. Early detection can lead to immediate therapeutic intervention improving further the quality of life. So, in this review, we wish to present a comprehensive overview of vertebral fracture imaging along with an algorithm of evaluation of vertebral fractures.

  16. Oportere ex fide bona. Una construcción decisiva de la jurisprudencia romana

    Directory of Open Access Journals (Sweden)

    Javier Humberto Facco

    2013-06-01

    Full Text Available Verificada la secularización de la antigua fides, asistimos al surgimiento de una construcción cuya valencia técnica parece concretarse en el específico ámbito del proceso. La fides resulta adjetivada con el calificativo de bona. A partir de entonces el sintagma bona fides significará una característica procesal, una cualidad de ciertas acciones que en la intentio de su fórmula se estructuraban en base al oportere ex fide bona. El núcleo de estas acciones estaba representado por los contratos sinalagmáticos, cuya fuerza obligatoria se fundaba en el consentimiento y pertenecían a la órbita del comercio internacional (ius gentium. Con todo, al margen de su aplicación pretoriana, la cláusula quidquid dare facere oportet ex fide bona fue una elaboración eminentemente jurisprudencial, producto del ingenio de los juristas romanos. Fueron ellos quienes idearon buena parte de las soluciones sobre cuestiones ligadas a la eficacia de los contratos consensuales que todavía hoy se consideran emanaciones de la buena fe-lealtad. Recuperar la trascendencia del rol de los juristas en la tarea de hacer que el derecho sea adherente a la realidad constituye la principal invitación que nace de este escrito.

  17. Oportere ex fide bona. Una construcción decisiva de la jurisprudencia romana

    Directory of Open Access Journals (Sweden)

    Javier Humberto Facco

    2013-07-01

    Full Text Available Verificada la secularización de la antigua fides, asistimos al surgimiento de una construcción cuya valencia técnica parece concretarse en el específico ámbito del proceso. La fides resulta adjetivada con el calificativo de bona. A partir de entonces el sintagma bona fides significará una característica procesal, una cualidad de ciertas acciones que en la intentio de su fórmula se estructuraban en base al oportere ex fide bona. El núcleo de estas acciones estaba representado por los contratos sinalagmáticos, cuya fuerza obligatoria se fundaba en el consentimiento y pertenecían a la órbita del comercio internacional (ius gentium. Con todo, al margen de su aplicación pretoriana, la cláusula quidquid dare facere oportet ex fide bona fue una elaboración eminentemente jurisprudencial, producto del ingenio de los juristas romanos. Fueron ellos quienes idearon buena parte de las soluciones sobre cuestiones ligadas a la eficacia de los contratos consensuales que todavía hoy se consideran emanaciones de la buena fe-lealtad. Recuperar la trascendencia del rol de los juristas en la tarea de hacer que el derecho sea adherente a la realidad constituye la principal invitación que nace de este escrito.

  18. Did FIDELIS projects contribute to the detection of new smear-positive pulmonary tuberculosis cases in China?

    Science.gov (United States)

    Lin, Y; Chiang, C-Y; Rusen, I D; Hinderaker, S G; Roldan, A; Heldal, E; Enarson, D A; Zhang, L-X

    2016-09-01

    Setting: The first phase of the Fund for Innovative DOTS Expansion through Local Initiatives to Stop TB (FIDELIS) projects in China started in 2003. Objective: To determine whether the FIDELIS projects contributed to the increased case detection rate for new smear-positive pulmonary tuberculosis (PTB) in China. Methods: We compared the case notification rates (CNRs) in the intervention year with those of the previous year in the FIDELIS areas, then compared the difference between the CNRs of the intervention year and the previous year in the FIDELIS areas with those in the non-FI-DELIS areas within the province. Results: There was an increase in the CNR in the intervention year compared with the previous year for all the project sites. The differences between the CNR in the intervention year and the previous year ranged from 6.4 to 31.1 per 100 000 population in the FIDELIS areas and from 2.9 to 20.4/100 000 in the non-FIDELIS areas. Differences-in-differences analysis shows that the differences in the CNRs in the FIDELIS areas were not statistically significantly different from those in the non-FIDELIS areas (P = 0.393). Conclusion: The FIDELIS projects may have contributed to the increase in case detection of new smear-positive PTB in China, but the level of evidence is low.

  19. Fracture of the styloid process associated with the mandible fracture

    Directory of Open Access Journals (Sweden)

    K N Dubey

    2013-01-01

    Full Text Available Fracture of the styloid process (SP of temporal bone is an uncommon injuries. Fracture of the SP can be associated with the facial injuries including mandible fracture. However, injury to the SP may be concealed and missed diagnosis may lead to the improper or various unnecessary treatments. A rare case of SP fracture associated with the ipsilateral mandibular fracture and also the diagnostic and management considerations of the SP fracture are discussed.

  20. FIDELIS--innovative approaches to increasing global case detection of tuberculosis.

    Science.gov (United States)

    Rusen, I D; Enarson, Donald A

    2006-01-01

    Tuberculosis was declared a global public health emergency in 1993. In 2003, only 45% of the world's estimated new smear-positive tuberculosis cases were detected-well below the 70% global case detection target set by the World Health Organization. The FIDELIS (Fund for Innovative DOTS Expansion Through Local Initiatives to Stop TB) initiative is a new global disease control initiative that has been developed to rapidly assess and implement innovative approaches to increase tuberculosis case detection. To date, 32 projects have been approved-covering approximately 378 million people in 13 countries-24 (75%) of which are in the world's 6 highest-burden countries. A wide range of target populations and interventions have been incorporated into successful FIDELIS projects. The FIDELIS initiative may serve as a model to discover best practices to address other urgent global public health problems.

  1. Fiat or bona fide boundary--a matter of granular perspective.

    Directory of Open Access Journals (Sweden)

    Lars Vogt

    Full Text Available BACKGROUND: Distinguishing bona fide (i.e. natural and fiat (i.e. artificial physical boundaries plays a key role for distinguishing natural from artificial material entities and is thus relevant to any scientific formal foundational top-level ontology, as for instance the Basic Formal Ontology (BFO. In BFO, the distinction is essential for demarcating two foundational categories of material entity: object and fiat object part. The commonly used basis for demarcating bona fide from fiat boundary refers to two criteria: (i intrinsic qualities of the boundary bearers (i.e. spatial/physical discontinuity, qualitative heterogeneity and (ii mind-independent existence of the boundary. The resulting distinction of bona fide and fiat boundaries is considered to be categorial and exhaustive. METHODOLOGY/PRINCIPAL FINDINGS: By Referring to various examples from biology, we demonstrate that the hitherto used distinction of boundaries is not categorial: (i spatial/physical discontinuity is a matter of scale and the differentiation of bona fide and fiat boundaries is thus granularity-dependent, and (ii this differentiation is not absolute, but comes in degrees. By reducing the demarcation criteria to mind-independence and by also considering dispositions and historical relations of the bearers of boundaries, instead of only considering their spatio-structural properties, we demonstrate with various examples that spatio-structurally fiat boundaries can nevertheless be mind-independent and in this sense bona fide. CONCLUSIONS/SIGNIFICANCE: We argue that the ontological status of a given boundary is perspective-dependent and that the strictly spatio-structural demarcation criteria follow a static perspective that is ignorant of causality and the dynamics of reality. Based on a distinction of several ontologically independent perspectives, we suggest different types of boundaries and corresponding material entities, including boundaries based on function

  2. [Periprosthetic Acetabulum Fractures].

    Science.gov (United States)

    Schreiner, A J; Stuby, F; de Zwart, P M; Ochs, B G

    2016-12-01

    In contrast to periprosthetic fractures of the femur, periprosthetic fractures of the acetabulum are rare complications - both primary fractures and fractures in revision surgery. This topic is largely under-reported in the literature; there are a few case reports and no long term results. Due to an increase in life expectancy, the level of patients' activity and the number of primary joint replacements, one has to expect a rise in periprosthetic complications in general and periprosthetic acetabular fractures in particular. This kind of fracture can be intra-, peri- or postoperative. Intraoperative fractures are especially associated with insertion of cementless press-fit acetabular components or revision surgery. Postoperative periprosthetic fractures of the acetabulum are usually related to osteolysis, for example, due to polyethylene wear. There are also traumatic fractures and fractures missed intraoperatively that lead to some kind of insufficiency fracture. Periprosthetic fractures of the acetabulum are treated conservatively if the implant is stable and the fracture is not dislocated. If surgery is needed, there are many possible different surgical techniques and challenging approaches. That is why periprosthetic fractures of the acetabulum should be treated by experts in pelvic surgery as well as revision arthroplasty and the features specific to the patient, fracture and prosthetic must always be considered. Georg Thieme Verlag KG Stuttgart · New York.

  3. Fides: Lightweight Authenticated Cipher with Side-Channel Resistance for Constrained Hardware

    NARCIS (Netherlands)

    Bilgin, Begül; Bogdanov, Andrey; Knezevic, Miroslav; Mendel, Florian; Wang, Qingju; Bertoni, G.; Coron, J.S.

    2013-01-01

    In this paper, we present a novel lightweight authenticated cipher optimized for hardware implementations called Fides. It is an online nonce-based authenticated encryption scheme with authenticated data whose area requirements are as low as 793 GE and 1001 GE for 80-bit and 96-bit security, respect

  4. 78 FR 9330 - Revision of Regulations Defining Bona Fide Cotton Spot Markets

    Science.gov (United States)

    2013-02-08

    ... Cotton Research and Promotion Act and to allow for published spot quotes to consider spot prices of... and Promotion Act and to allow for ] published spot quotes to consider spot prices of cotton marketed... Cotton Research and Promotion Act. Updated bona fide spot market definitions will allow for...

  5. 15 CFR 8a.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Sex as a bona fide occupational... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 8a.550 Sex as...

  6. 22 CFR 229.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Sex as a bona fide occupational qualification... THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 229.550 Sex...

  7. 13 CFR 113.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Sex as a bona fide occupational... ADMINISTRATOR Nondiscrimination on the Basis of Sex in Education Programs or Activities Receiving Federal Financial Assistance Discrimination on the Basis of Sex in Employment in Education Programs Or...

  8. 43 CFR 41.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Sex as a bona fide occupational... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 41.550 Sex as...

  9. 22 CFR 146.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Sex as a bona fide occupational qualification... BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 146.550 Sex as...

  10. 29 CFR 36.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Sex as a bona fide occupational qualification. 36.550 Section 36.550 Labor Office of the Secretary of Labor NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex...

  11. 34 CFR 106.61 - Sex as a bona-fide occupational qualification.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Sex as a bona-fide occupational qualification. 106.61..., DEPARTMENT OF EDUCATION NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs...

  12. 38 CFR 23.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Sex as a bona fide... VETERANS AFFAIRS (CONTINUED) NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in...

  13. 45 CFR 618.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Sex as a bona fide occupational qualification. 618... FOUNDATION NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or...

  14. 32 CFR 196.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Sex as a bona fide occupational qualification... DEFENSE (CONTINUED) MISCELLANEOUS NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment...

  15. 6 CFR 17.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-01-01

    ... 6 Domestic Security 1 2010-01-01 2010-01-01 false Sex as a bona fide occupational qualification... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 17.550 Sex as...

  16. 10 CFR 5.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Sex as a bona fide occupational qualification. 5.550 Section 5.550 Energy NUCLEAR REGULATORY COMMISSION NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex...

  17. 40 CFR 5.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Sex as a bona fide occupational... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 5.550 Sex as...

  18. 24 CFR 3.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Sex as a bona fide occupational... and Urban Development NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in...

  19. 45 CFR 86.61 - Sex as a bona-fide occupational qualification.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Sex as a bona-fide occupational qualification. 86... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 86.61 Sex as...

  20. 18 CFR 1317.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Sex as a bona fide... VALLEY AUTHORITY NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs...

  1. 10 CFR 1042.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Sex as a bona fide occupational qualification. 1042.550 Section 1042.550 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of...

  2. 14 CFR 1253.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Sex as a bona fide occupational... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 1253.550 Sex...

  3. 45 CFR 2555.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Sex as a bona fide occupational qualification... FOR NATIONAL AND COMMUNITY SERVICE NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment...

  4. 41 CFR 101-4.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Sex as a bona fide... ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 101-4.550...

  5. 36 CFR 1211.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Sex as a bona fide occupational qualification. 1211.550 Section 1211.550 Parks, Forests, and Public Property NATIONAL ARCHIVES AND... to such action is essential to successful operation of the employment function concerned. A...

  6. 44 CFR 19.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Sex as a bona fide... MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY GENERAL NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex...

  7. 49 CFR 25.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Sex as a bona fide occupational qualification. 25... BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 25.550 Sex as...

  8. 31 CFR 28.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Sex as a bona fide occupational... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 28.550 Sex as...

  9. 28 CFR 54.550 - Sex as a bona fide occupational qualification.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Sex as a bona fide occupational... ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 54.550 Sex as...

  10. Failure of implantable cardioverter-defibrillator leads: a matter of lead size?

    Science.gov (United States)

    Rordorf, Roberto; Poggio, Luca; Savastano, Simone; Vicentini, Alessandro; Petracci, Barbara; Chieffo, Enrico; Klersy, Catherine; Landolina, Maurizio

    2013-02-01

    Small-diameter implantable cardioverter-defibrillator (ICD) Sprint Fidelis and Riata leads have been recalled owing to an increased risk of lead failure, thus arousing the suspicion that lead size might be a critical issue. To compare the incidence of failure of small-diameter (≤8 F) and standard-diameter (>8 F) ICD leads implanted in a single center. From January 2003 to December 2010, 190 Sprint Fidelis, 182 Riata/Riata ST, 99 Optim (Riata Optim/Durata), and 419 standard-diameter leads were implanted in our center. During a median follow-up of 33 months, the overall failure rate was 6.3%. Follow-up duration was similar for Sprint Fidelis, Riata, and standard-diameter leads but shorter for the Optim group. The failure rate was significantly higher in Sprint Fidelis leads than in both standard-diameter (4.8%/year vs 0.8%/year; P<.001) and Riata/Riata ST (4.8%/year vs 2.6%/year; P = .03) leads. The incidence of lead failure in Riata/Riata ST leads proved significantly higher than in standard-diameter leads (2.6%/year vs 0.8%/year; P = .001). No cases of lead failure were recorded in the Optim group. On multivariable analyses, small-diameter (hazard ratio [HR] 5.03, 2.53-10.01, P<.001), Sprint Fidelis (HR 6.3, 3.1-13.3, P<.001), or Riata/Riata ST (HR 4.5, 1.9-10.5, P = .001) leads and age<60 years (HR 2.3, 1.3-4.3, P = .005) were found to independently increase the risk of lead failure. Compared with standard-diameter leads, both Sprint Fidelis and Riata/Riata ST small-diameter ICD leads are at an increased risk of failure, although the incidence of events is significantly lower in the Riata than in the Sprint Fidelis group. Copyright © 2013 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  11. Imaging of insufficiency fractures

    Energy Technology Data Exchange (ETDEWEB)

    Krestan, Christian [Department of Radiology, Medical University of Vienna, Vienna General Hospital, Waehringerstr. 18-20, 1090 Vienna (Austria)], E-mail: christian.krestan@meduniwien.ac.at; Hojreh, Azadeh [Department of Radiology, Medical University of Vienna, Vienna General Hospital, Waehringerstr. 18-20, 1090 Vienna (Austria)

    2009-09-15

    This review focuses on the occurrence, imaging and differential diagnosis of insufficiency fractures. Prevalence, the most common sites of insufficiency fractures and their clinical implications are discussed. Insufficiency fractures occur with normal stress exerted on weakened bone. Postmenopausal osteoporosis is the most common cause of insufficiency fractures. Other conditions which affect bone turnover include osteomalacia, hyperparathyroidism, chronic renal failure and high-dose glucocorticoid therapy. It is a challenge for the radiologist to detect and diagnose insufficiency fractures, and to differentiate them from other bone lesions. Radiographs are still the most widely used imaging method for identification of insufficiency fractures, but sensitivity is limited, depending on the location of the fractures. Magnetic resonance imaging (MRI) is a very sensitive tool to visualize bone marrow abnormalities associated with insufficiency fractures. Thin section, multi-detector computed tomography (MDCT) depicts subtle fracture lines allowing direct visualization of cortical and trabecular bone. Bone scintigraphy still plays a role in detecting fractures, with good sensitivity but limited specificity. The most important differential diagnosis is underlying malignant disease leading to pathologic fractures. Bone densitometry and clinical history may also be helpful in confirming the diagnosis of insufficiency fractures.

  12. Treatment delay among tuberculosis patients in Tanzania: Data from the FIDELIS Initiative

    Directory of Open Access Journals (Sweden)

    Enarson Donald A

    2011-05-01

    Full Text Available Abstract Background Several FIDELIS projects (Fund for Innovative DOTS Expansion through Local Initiatives to Stop TB in Tanzania were conducted by the National Tuberculosis and Leprosy Programme (NTLP during the years 2004-2008 to strengthen diagnostic and treatment services. These projects collected information on treatment delay and some of it was available for research purposes. With this database our objective was to assess the duration and determinants of treatment delay among new smear positive pulmonary tuberculosis (TB patients in FIDELIS projects, and to compare delay according to provider visited prior to diagnosis. Methods Treatment delay among new smear positive TB patients was recorded for each patient at treatment initiation and this information was available and fairly complete in 6 out of 57 districts with FIDELIS projects enrolling patients between 2004 and 2007; other districts had discarded their forms at the time of analysis. It was analysed as a cross sectional study. Results We included 1161 cases, 10% of all patients recruited in the FIDELIS projects in Tanzania. Median delay was 12 weeks. The median duration of cough, weight loss and haemoptysis was 12, 8 and 3 weeks, respectively. Compared to Hai district Handeni had patients with longer delays and Mbozi had patients with shorter delays. Urban and rural patients reported similar delays. Patients aged 15-24 years and patients of 65 years or older had longer delays. Patients reporting contact with traditional healers before diagnosis had a median delay of 15 weeks compared to 12 weeks among those who did not. Patients with dyspnoea and with diarrhoea had longer delays. Conclusion In this patient sample in Tanzania half of the new smear positive pulmonary tuberculosis patients had a treatment delay longer than 12 weeks. Delay was similar in men and women and among urban and rural patients, but longer in the young and older age groups. Patients using traditional healers had

  13. Cementless Titanium Mesh Fixation of Osteoporotic Burst Fractures of the Lumbar Spine Leads to Bony Healing: Results of an Experimental Sheep Model

    Directory of Open Access Journals (Sweden)

    Anica Eschler

    2016-01-01

    Full Text Available Introduction. Current treatment strategies for osteoporotic vertebral compression fractures (VCFs focus on cement-associated solutions. Complications associated with cement application are leakage, embolism, adjacent fractures, and compromise in bony healing. This study comprises a validated VCF model in osteoporotic sheep in order to (1 evaluate a new cementless fracture fixation technique using titanium mesh implants (TMIs and (2 demonstrate the healing capabilities in osteoporotic VCFs. Methods. Twelve 5-year-old Merino sheep received ovariectomy, corticosteroid injections, and a calcium/phosphorus/vitamin D-deficient diet for osteoporosis induction. Standardized VCFs (type AO A3.1 were created, reduced, and fixed using intravertebral TMIs. Randomly additional autologous spongiosa grafting (G1 or no augmentation was performed (G2, n=6 each. Two months postoperatively, macroscopic, micro-CT and biomechanical evaluation assessed bony consolidation. Results. Fracture reduction succeeded in all cases without intraoperative complications. Bony consolidation was proven for all cases with increased amounts of callus development for G2 (58.3%. Micro-CT revealed cage integration. Neither group showed improved results with biomechanical testing. Conclusions. Fracture reduction/fixation using TMIs without cement in osteoporotic sheep lumbar VCF resulted in bony fracture healing. Intravertebral application of autologous spongiosa showed no beneficial effects. The technique is now available for clinical use; thus, it offers an opportunity to abandon cement-associated complications.

  14. Growing skull fracture

    Directory of Open Access Journals (Sweden)

    Mihajlović Miljan H.

    2006-01-01

    Full Text Available Background. Growing skull fracture or craniocerebral erosion is a rare complication of linear skull fracture in childhood. It is characterized by progressive diastatic enlargement of the fracture line, which leads to a cranial defect, dural cleft, and cerebral herniation. It is presented as a soft pulsabile scalp swelling above the fracture, with a clear cranial defect. Case report. In this paper we presented a patient, an 8-month-old boy with the growing skull fracture revealed four weeks after the injury. After the surgical treatment, the boy was in a good general condition without the presence of neurologic impairment. Conclusion. Early recognition of craniocerebral erosion is very important. Timely detection prevents further progression of the disease and the evolution of neurological impairment. Surgery is the method of choice for treating a growing skull fracture .

  15. Hip Fracture

    Science.gov (United States)

    Diseases and Conditions Hip fracture By Mayo Clinic Staff A hip fracture is a serious injury, with complications that can be life-threatening. The risk of hip fracture rises with age. Older people are at a ...

  16. Fides: Lightweight Authenticated Cipher with Side-Channel Resistance for Constrained Hardware

    DEFF Research Database (Denmark)

    Bilgin, Begul; Bogdanov, Andrey; Knezevic, Miroslav

    2013-01-01

    In this paper, we present a novel lightweight authenticated cipher optimized for hardware implementations called Fides. It is an online nonce-based authenticated encryption scheme with authenticated data whose area requirements are as low as 793 GE and 1001 GE for 80-bit and 96-bit security, resp......, cryptographically optimal 5-bit and 6-bit S-boxes are used as basic nonlinear components while paying a special attention on the simplicity of providing first order side-channel resistance with threshold implementation....

  17. ‘In fide constans’? Politiek van herinnering in het Mechelse stadsbestuur

    Directory of Open Access Journals (Sweden)

    Bram Caers

    2013-12-01

    Full Text Available Around 1600, the Mechelen mayor Jan van Wachtendonck wrote an urban chronicle of his town that thoroughly revised the existing chronicle dating about a century back. Wachtendonck's text presents a version in which Mechelen sides firmly with the princely authorities, notably the Burgundian dukes. This contribution shows that the revision of Mechelen's history is part of a broader policy of memory initiated by the city council after the calvinist regime (1580-1585. Through text and image, the new council aimed to reassert the city's image as a catholic and loyal capital, in accordance with its motto 'in fide constans'.

  18. The Galactic Cepheid period-luminosity relation revisited using bona fide cluster Cepheids

    Science.gov (United States)

    Anderson, Richard I.; Mowlavi, Nami; Eyer, Laurent

    2013-02-01

    Classical Cepheids in Galactic open clusters (cluster Cepheids: CCs) have been studied extensively for multiple decades, thanks to their importance as calibrators of the Galactic Cepheid period-luminosity relation (PLR). Here we revisit the calibration of the Galactic PLR using a new sample of CCs, since even recent calibrations show significant discrepancies. The CC sample employed for the calibration is based on the preliminary results of a self-consistent, eight-dimensional all-sky census. This census is based mostly on literature data, supplemented with high-precision radial-velocity observations from both hemispheres. New CCs are identified from our census and the degree of confidence in membership is quantified for known candidates. Using only bona fide CCs, we obtain MV = (-3.08 +/- 0.50) log P + (-0.94 +/- 0.42) mag, which is in perfect agreement with the results by Sandage, Tammann, and Reindl, albeit with larger error bars and an rms of 0.21 mag. The key to obtaining a meaningful calibration is to employ accurate cluster distance moduli and space reddening values. A homogeneous study of all bona fide host clusters would be desirable to increase precision and confidence in the calibration.

  19. Fides et ratio: An early enlightenment defence of non-confessional religion by poiret and his circle

    NARCIS (Netherlands)

    H.A. Krop (Henri)

    2010-01-01

    textabstractIn 1707 an anonymous collection of treatises Fides et ratio was published in Amsterdam. The voluminous work of several authors contains a fierce critique of Locke's notion of faith and the moderate Enlightenment's conception of a reasonable Christianity. The sympathiser with mystic

  20. Fides et ratio: An early enlightenment defence of non-confessional religion by poiret and his circle

    NARCIS (Netherlands)

    H.A. Krop (Henri)

    2010-01-01

    textabstractIn 1707 an anonymous collection of treatises Fides et ratio was published in Amsterdam. The voluminous work of several authors contains a fierce critique of Locke's notion of faith and the moderate Enlightenment's conception of a reasonable Christianity. The sympathiser with mystic theol

  1. 78 FR 20642 - Notice of Proposed CERCLA Agreement and Order on Consent for Removal Action by Bona Fide...

    Science.gov (United States)

    2013-04-05

    ... Chromium Operable Unit, 264 W. Spazier Ave., Burbank, California ACTION: Notice; request for public comment... Valley Area 2 Superfund Site, Glendale Chromium Operable Unit, located at 264 W. Spazier Ave., Burbank... May 31, 2012 (Purchaser), the Bona Fide Prospective Purchaser of 264 W. Spazier Ave.,...

  2. Fides et ratio: An early enlightenment defence of non-confessional religion by poiret and his circle

    NARCIS (Netherlands)

    H.A. Krop (Henri)

    2010-01-01

    textabstractIn 1707 an anonymous collection of treatises Fides et ratio was published in Amsterdam. The voluminous work of several authors contains a fierce critique of Locke's notion of faith and the moderate Enlightenment's conception of a reasonable Christianity. The sympathiser with mystic theol

  3. [Atlas fractures].

    Science.gov (United States)

    Schären, S; Jeanneret, B

    1999-05-01

    Fractures of the atlas account for 1-2% of all vertebral fractures. We divide atlas fractures into 5 groups: isolated fractures of the anterior arch of the atlas, isolated fractures of the posterior arch, combined fractures of the anterior and posterior arch (so-called Jefferson fractures), isolated fractures of the lateral mass and fractures of the transverse process. Isolated fractures of the anterior or posterior arch are benign and are treated conservatively with a soft collar until the neck pain has disappeared. Jefferson fractures are divided into stable and unstable fracture depending on the integrity of the transverse ligament. Stable Jefferson fractures are treated conservatively with good outcome while unstable Jefferson fractures are probably best treated operatively with a posterior atlanto-axial or occipito-axial stabilization and fusion. The authors preferred treatment modality is the immediate open reduction of the dislocated lateral masses combined with a stabilization in the reduced position using a transarticular screw fixation C1/C2 according to Magerl. This has the advantage of saving the atlanto-occipital joints and offering an immediate stability which makes immobilization in an halo or Minerva cast superfluous. In late instabilities C1/2 with incongruency of the lateral masses occurring after primary conservative treatment, an occipito-cervical fusion is indicated. Isolated fractures of the lateral masses are very rare and may, if the lateral mass is totally destroyed, be a reason for an occipito-cervical fusion. Fractures of the transverse processes may be the cause for a thrombosis of the vertebral artery. No treatment is necessary for the fracture itself.

  4. Root fractures

    DEFF Research Database (Denmark)

    Andreasen, Jens Ove; Christensen, Søren Steno Ahrensburg; Tsilingaridis, Georgios

    2012-01-01

    The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed.......The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed....

  5. Stress Fractures

    Science.gov (United States)

    Stress fractures Overview Stress fractures are tiny cracks in a bone. They're caused by repetitive force, often from overuse — such as repeatedly jumping up and down or running long distances. Stress fractures can also arise from normal use of ...

  6. Unsolved issues in diagnostics and treatment decisions for clavicular fractures

    NARCIS (Netherlands)

    Stegeman, Sylvia Alexandra

    2015-01-01

    Clavicular fractures are among the most common fractures of the shoulder. Displacement or comminution of the fracture fragments may lead to shortening of the clavicle, but could also cause mal-union or non-union of the clavicle and might lead to poor functional outcome. These fracture characteristic

  7. Hydraulic fracture propagation modeling and data-based fracture identification

    Science.gov (United States)

    Zhou, Jing

    Successful shale gas and tight oil production is enabled by the engineering innovation of horizontal drilling and hydraulic fracturing. Hydraulically induced fractures will most likely deviate from the bi-wing planar pattern and generate complex fracture networks due to mechanical interactions and reservoir heterogeneity, both of which render the conventional fracture simulators insufficient to characterize the fractured reservoir. Moreover, in reservoirs with ultra-low permeability, the natural fractures are widely distributed, which will result in hydraulic fractures branching and merging at the interface and consequently lead to the creation of more complex fracture networks. Thus, developing a reliable hydraulic fracturing simulator, including both mechanical interaction and fluid flow, is critical in maximizing hydrocarbon recovery and optimizing fracture/well design and completion strategy in multistage horizontal wells. A novel fully coupled reservoir flow and geomechanics model based on the dual-lattice system is developed to simulate multiple nonplanar fractures' propagation in both homogeneous and heterogeneous reservoirs with or without pre-existing natural fractures. Initiation, growth, and coalescence of the microcracks will lead to the generation of macroscopic fractures, which is explicitly mimicked by failure and removal of bonds between particles from the discrete element network. This physics-based modeling approach leads to realistic fracture patterns without using the empirical rock failure and fracture propagation criteria required in conventional continuum methods. Based on this model, a sensitivity study is performed to investigate the effects of perforation spacing, in-situ stress anisotropy, rock properties (Young's modulus, Poisson's ratio, and compressive strength), fluid properties, and natural fracture properties on hydraulic fracture propagation. In addition, since reservoirs are buried thousands of feet below the surface, the

  8. A discussion on the causes of children distal humerus fractures leading to cubitus varus%儿童肱骨远端骨折致肘内翻形成原因的探讨

    Institute of Scientific and Technical Information of China (English)

    张天久; 俞松; 杨小红

    2015-01-01

    目的:探讨儿童肱骨远端骨折致肘内翻形成的原因及机制,为手术矫正肘内翻提供临床参考。方法回顾性研究2009年1月至2014年2月,我科收治的肘内翻畸形患儿65例,男51例,女14例,年龄4~14岁,平均7.5岁;所有患儿均有明确的肱骨远端骨折病史,其中31例为肱骨髁上骨折,2例为肱骨外髁骨折,3例为肱骨内髁骨折,3例为肱骨远端全骨骺分离,26例具体骨折诊断不详。观察所有患儿的患侧肘关节正侧位 X 线片,与对侧肘关节或正常肘关节正侧位 X 线片比较,观察骨折愈合后残留的影像学痕迹及肱骨远端骨骺发育情况,测量肘内翻角度,观察肱骨内、外髁大小形态,尺骨鹰嘴窝、肱尺关节形态,滑车改变,肱骨头前倾角,骺板发育情况等。将骨折畸形愈合导致的肘内翻和肱骨远端内外侧骨骺生长发育不平衡导致的肘内翻分两类进行对比,分析肘内翻形成的原因及机制。结果58例肘内翻主要因骨折畸形愈合所致,占89.2%,其中包括诊断明确的31例肱骨髁上骨折、2例为肱骨外髁骨折和2例肱骨远端全骨骺分离;7例肘内翻主要为肱骨远端内外侧骨骺生长发育不平衡所造成,包括3例肱骨内髁骨折和1例为肱骨远端全骨骺分离。结论临床上儿童肘内翻绝大部分由肱骨远端骨折后畸形愈合所致,但少部分可由肱骨远端骨骺生长发育不平衡所引起,在手术截骨矫正该类型的肘内翻时,需考虑到患儿的年龄及肘关节生长潜力,适度矫枉过正,提高治疗效果,减少术后复发率。%Objective To explore the causes and mechanism of children distal humerus fractures leading to cubitus varus and to provide a clinical reference for surgical correction.Methods From January 2009 to February 2014, 65 children with cubitus varus were adopted, whose clinical data were retrospectively studied. There were 51

  9. Oxygen vacancies lead to loss of domain order, particle fracture, and rapid capacity fade in lithium manganospinel (LiMn₂O₄) batteries.

    Science.gov (United States)

    Hao, Xiaoguang; Lin, Xianke; Lu, Wei; Bartlett, Bart M

    2014-07-23

    Spinel-structured lithium manganese oxide (LiMn2O4) has attracted much attention because of its high energy density, low cost, and environmental impact. In this article, structural analysis methods such as powder neutron diffraction (PND), X-ray diffraction (XRD), and high-resolution transmission and scanning electron microscopies (TEM & SEM) reveal the capacity fading mechanism of LiMn2O4 as it relates to the mechanical degradation of the material. Micro-fractures form after the first charge (to 4.45 V vs. Li(+/0)) of a commercial lithium manganese oxide phase, best represented by the formula LiMn2O3.88. Diffraction methods show that the grain size decreases and multiple phases form after 850 electrochemical cycles at 0.2 C current. The microfractures are directly observed through microscopy studies as particle cracks propagate along the (1 1 1) planes, with clear lattice twisting observed along this direction. Long-term galvanostatic cycling results in increased charge-transfer resistance and capacity loss. Upon preparing samples with controlled oxygen contents, LiMn2O4.03 and LiMn2O3.87, the mechanical failure of the lithium manganese oxide can be correlated to the oxygen vacancies in the materials, providing guidance for better synthesis methods.

  10. White Spot Syndrome Virus Orf514 Encodes a Bona Fide DNA Polymerase

    Directory of Open Access Journals (Sweden)

    Rogerio R. Sotelo-Mundo

    2011-01-01

    Full Text Available White spot syndrome virus (WSSV is the causative agent of white spot syndrome, one of the most devastating diseases in shrimp aquaculture. The genome of WSSV includes a gene that encodes a putative family B DNA polymerase (ORF514, which is 16% identical in amino acid sequence to the Herpes virus 1 DNA polymerase. The aim of this work was to demonstrate the activity of the WSSV ORF514-encoded protein as a DNA polymerase and hence a putative antiviral target. A 3.5 kbp fragment encoding the conserved polymerase and exonuclease domains of ORF514 was overexpressed in bacteria. The recombinant protein showed polymerase activity but with very low level of processivity. Molecular modeling of the catalytic protein core encoded in ORF514 revealed a canonical polymerase fold. Amino acid sequence alignments of ORF514 indicate the presence of a putative PIP box, suggesting that the encoded putative DNA polymerase may use a host processivity factor for optimal activity. We postulate that WSSV ORF514 encodes a bona fide DNA polymerase that requires accessory proteins for activity and maybe target for drugs or compounds that inhibit viral DNA replication.

  11. MN48: a new Galactic bona fide luminous blue variable revealed by Spitzer and SALT

    Science.gov (United States)

    Kniazev, A. Y.; Gvaramadze, V. V.; Berdnikov, L. N.

    2016-07-01

    In this paper, we report the results of spectroscopic and photometric observations of the candidate evolved massive star MN48 disclosed via detection of a mid-infrared circular shell around it with the Spitzer Space Telescope. Follow-up optical spectroscopy of MN48 with the Southern African Large Telescope (SALT) carried out in 2011-2015 revealed significant changes in the spectrum of this star, which are typical of luminous blue variables (LBVs). The LBV status of MN48 was further supported by photometric monitoring which shows that in 2009-2011 this star has brightened by ≈0.9 and 1 mag in the V and Ic bands, respectively, then faded by ≈1.1 and 1.6 mag during the next four years, and apparently started to brighten again recently. The detected changes in the spectrum and brightness of MN48 make this star the 18th known Galactic bona fide LBV and increase the percentage of LBVs associated with circumstellar nebulae to more than 70 per cent. We discuss the possible birth place of MN48 and suggest that this star might have been ejected either from a putative star cluster embedded in the H II region IRAS 16455-4531 or the young massive star cluster Westerlund 1.

  12. MN48: a new Galactic bona fide luminous blue variable revealed by Spitzer and SALT

    CERN Document Server

    Kniazev, A Y; Berdnikov, L N

    2016-01-01

    In this paper, we report the results of spectroscopic and photometric observations of the candidate evolved massive star MN48 disclosed via detection of a mid-infrared circular shell around it with the Spitzer Space Telescope. Follow-up optical spectroscopy of MN48 with the Southern African Large Telescope (SALT) carried out in 2011--2015 revealed significant changes in the spectrum of this star, which are typical of luminous blue variables (LBVs). The LBV status of MN48 was further supported by photometric monitoring which shows that in 2009--2011 this star has brightened by approx 0.9 and 1 mag in the V and I_c bands, respectively, then faded by approx 1.1 and 1.6 mag during the next four years, and apparently started to brighten again recently. The detected changes in the spectrum and brightness of MN48 make this star the 18th known Galactic bona fide LBV and increase the percentage of LBVs associated with circumstellar nebulae to more than 70 per cent. We discuss the possible birth place of MN48 and sugge...

  13. Direct Reading of Bona Fide Barcode Assays for Diagnostics with Smartphone Apps

    Science.gov (United States)

    Wong, Jessica X. H.; Li, Xiaochun; Liu, Frank S. F.; Yu, Hua-Zhong

    2015-06-01

    The desire to develop new point-of-care (POC) diagnostic tools has led to the adaptation of smartphones to tackle limitations in state-of-the-art instrumentation and centralized laboratory facilities. Today’s smartphones possess the computer-like ability to image and process data using mobile apps; barcode scanners are one such type of apps. We demonstrate herein that a diagnostic assay can be performed by patterning immunoassay strips in a bona fide barcode format such that after target binding and signal enhancement, the linear barcode can be read directly with a standard smartphone app. Quantitative analysis can then be performed based on the grayscale intensities with a customized mobile app. This novel diagnostic concept has been validated for a real-world application, i.e., the detection of human chorionic gonadotropin, a pregnancy hormone. With the possibility of multiplex detection, the barcode assay protocol promises to boost POC diagnosis research by the direct adaptation of mobile devices and apps.

  14. Discovery of a new bona fide luminous blue variable in Norma

    CERN Document Server

    Gvaramadze, V V; Berdnikov, L N

    2015-01-01

    We report the results of optical spectroscopy of the candidate evolved massive star MN44 revealed via detection of a circular shell with the Spitzer Space Telescope. First spectra taken in 2009 May--June showed the Balmer lines in emission as well as numerous emission lines of iron, which is typical of luminous blue variables (LBVs) near the visual maximum. New observations carried out in 2015 May--September detected significant changes in the spectrum, indicating that the star became hotter. We found that these changes are accompanied by significant brightness variability of MN44. In particular, the I_c-band brightness decreased by \\approx 1.6 mag during the last six years and after reaching its minimum in 2015 June has started to increase. Using archival data, we also found that the I_c-band brightness increased by \\approx 3 mag in \\approx 30 yr preceding our observations. MN44 therefore represents the seventeenth known example of the Galactic bona fide LBVs. We detected a nitrogen-rich knot to the northwes...

  15. [Acetabular fractures].

    Science.gov (United States)

    Gänsslen, A; Oestern, H J

    2011-12-01

    Treatment of acetabular fractures requires extensive knowledge of the bony anatomy, the amount of possible exposure of the bone with the selected approaches and fracture type-dependent indications of operative treatment. Classification of the fracture with detailed analysis of the fracture morphology is the basis for decision making and planning. The primary treatment aim is the anatomic reconstruction of the acetabulum which results in optimal long-term results.The basis of this overview is the presentation of standard treatment concepts in acetabular fracture surgery. Beside characteristics of the acetabular bony anatomy, biomechanical and pathomechanical principles and the relevant radiological anatomy, the treatment options, both conservative and operative and basic principles of the indications for standard surgical approaches will be discussed.The special fracture type is discussed in detail regarding incidence, injury mechanism, concomitant injuries, options for conservative and operative treatment, quality of operative reduction and long-term results.Furthermore, epidemiological data on typical postoperative complications are evaluated.

  16. Double segmental tibial fractures - an unusual fracture pattern

    Directory of Open Access Journals (Sweden)

    Bali Kamal

    2012-02-01

    Full Text Available 【Abstract】A case of a 50-year-old pedestrian who was hit by a bike and suffered fractures of both bones of his right leg was presented. Complete clinical and radiographic assessment showed double segmental fractures of the tibia and multisegmental fractures of the fibula. Review of the literature revealed that this fracture pattern was unique and only a single case was reported so far. Moreover, we discussed the possible mechanisms which can lead to such an injury. We also discussed the management of segmental tibial fracture and the difficulties encountered with them. This case was managed by modern osteosynthesis tech- nique with a pleasing outcome. Key words: Fracture, bone; Tibia; Fibula; Nails

  17. Validity of Contract in Bona Fide Acquisition%论善意取得中合同的效力

    Institute of Scientific and Technical Information of China (English)

    林耕宇

    2012-01-01

    Taking hot social issues as a starting point, the problem of identification of validity of contract in bona fide acquisition is focused on. In the context of general rule of transferring property right which was stipulated in Property Law, claiming the validity of contract of bona fide acquisition would confront obstacles both in theory and practice. The argument that the contract of bona fide acquisition to be validity can only be established on the basis of the admission of juristic act to jus in rein. If the Judicial system of our country still can not adopt such a theory, it should be insisted that the contract of bona fide acquisition shall be consider to be invalid.%以社会热点问题为出发点,重点论述善意取得合同的效力认定问题。认为在我国债权形式主义的物权转移模式背景下,主张善意取得合同有效存在着理论与实践上的障碍。认定无权处分合同有效只能建立在承认物权行为理论的基础上。在我国司法实践中如果尚不能作出这种变革则应当坚持无权处分合同无效的观点,对于其在实践中可能存在的问题可以通过适当司法解释予以解决。

  18. Sports fractures.

    OpenAIRE

    DeCoster, T. A.; Stevens, M. A.; Albright, J. P.

    1994-01-01

    Fractures occur in athletes and dramatically influence performance during competitive and recreational activities. Fractures occur in athletes as the result of repetitive stress, acute sports-related trauma and trauma outside of athletics. The literature provides general guidelines for treatment as well as a variety of statistics on the epidemiology of fractures by sport and level of participation. Athletes are healthy and motivated patients, and have high expectations regarding their level o...

  19. Hamate fractures.

    Science.gov (United States)

    Sarabia Condés, J M; Ibañez Martínez, L; Sánchez Carrasco, M A; Carrillo Julia, F J; Salmerón Martínez, E L

    2015-01-01

    The purpose of this paper is to present our experience in the treatment of the fractures of the hamate and to make a review of the literature on this topic. We retrospectively reviewed 10 patients treated in our clinic between 2005-2012 suffering from fractures of the hamate. Six cases were fractures of the body and four were fractures of the hamate. Five cases were of associated injuries. Diagnostic delay ranged from 30 days to 2 years. Patient follow-up ranged from 1 to 10 years. Patient satisfaction was evaluated using the DASH questionnaire. Five patients with a fracture of the body underwent surgery, and one was treated conservatively. Two patients with fracture of the hook of the hamate were treated with immobilization, and two more patients had the fragment removed. The grip strength and the digital clip were reduced in 2 cases. Flexion and extension of the wrist was limited in 3 cases. The mobility of the fingers was normal in all the cases, except in one. The results obtained from the DASH questionnaire were normal in all the cases, except in one case of fracture of the hamate, and in two cases of fracture of the body. The surgical treatment should reduce the dislocation and stabilize the injuries with osteosynthesis. The fractures of the hamate are usually diagnosed late, and the most recommended treatment is removal of the fragment, although it cannot be deduced from this study. Copyright © 2014 SECOT. Published by Elsevier Espana. All rights reserved.

  20. Colles Fracture

    OpenAIRE

    Sánchez León, Belisario; Facultad de Medicina, Universidad Nacional Mayor de San Marcos, Lima, Perú

    2014-01-01

    Our expertise is the study of more than 2,000 cases of Colles' fractures. Colles name should in this case to synthesize the type of fractures of the lower end of the radius. There have been various proposed classifications according to the different fracture lines can be demonstrated radiologically in the region of the wrist. We believe that these ratings should only be retained if the concept of the articular fracture or not in the classical sense, since it has great value in the functional ...

  1. New C2 synchondrosal fracture classification system

    Energy Technology Data Exchange (ETDEWEB)

    Rusin, Jerome A.; Ruess, Lynne [Department of Radiology, Nationwide Children' s Hospital, Columbus, OH (United States); The Ohio State University College of Medicine and Public Health, Columbus, OH (United States); Daulton, Robert S. [Department of Radiology, Nationwide Children' s Hospital, Columbus, OH (United States)

    2015-06-15

    Excessive cervical flexion-extension accompanying mild to severe impact injuries can lead to C2 synchondrosal fractures in young children. To characterize and classify C2 synchondrosal fracture patterns. We retrospectively reviewed imaging and medical records of children who were treated for cervical spine fractures at our institution between 1995 and 2014. We reviewed all fractures involving the five central C2 synchondroses with regard to patient demographics, mechanism of injury, fracture pattern, associated fractures and other injuries, treatment plans and outcome. Fourteen children had fractures involving the central C2 synchondroses. There were nine boys and five girls, all younger than 6 years. We found four distinct fracture patterns. Eleven complete fractures were further divided into four subtypes (a, b, c and d) based on degree of anterior displacement of the odontoid segment and presence of distraction. Nine of these 11 children had fractures through both odontoneural synchondroses and the odontocentral synchondrosis; one had fractures involving both neurocentral synchondroses and the odontoneural synchondrosis; one had fractures through bilateral odontoneural and bilateral neurocentral synchondroses. Three children had incomplete fractures, defined as a fracture through a single odontoneural synchondrosis with or without partial extension into either the odontocentral or the adjacent neurocentral synchondroses. All complete fractures were displaced or angulated. Four had associated spinal cord injury, including two contusions (subtype c fractures) and two fatal transections (subtype d fractures). Most children were treated with primary halo stabilization. Subtype c fractures required surgical fixation. We describe four patterns of central C2 synchondrosal fractures, including two unique patterns that have not been reported. We propose a classification system to distinguish these fractures and aid in treatment planning. (orig.)

  2. Fracture Mechanics

    CERN Document Server

    Zehnder, Alan T

    2012-01-01

    Fracture mechanics is a vast and growing field. This book develops the basic elements needed for both fracture research and engineering practice. The emphasis is on continuum mechanics models for energy flows and crack-tip stress- and deformation fields in elastic and elastic-plastic materials. In addition to a brief discussion of computational fracture methods, the text includes practical sections on fracture criteria, fracture toughness testing, and methods for measuring stress intensity factors and energy release rates. Class-tested at Cornell, this book is designed for students, researchers and practitioners interested in understanding and contributing to a diverse and vital field of knowledge. Alan Zehnder joined the faculty at Cornell University in 1988. Since then he has served in a number of leadership roles including Chair of the Department of Theoretical and Applied Mechanics, and Director of the Sibley School of Mechanical and Aerospace Engineering.  He teaches applied mechanics and his research t...

  3. Fractured Petroleum Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Firoozabadi, Dr. Abbas

    2000-01-18

    In this report the results of experiments of water injection in fractured porous media comprising a number of water-wet matrix blocks are reported for the first time. The blocks experience an advancing fracture-water level (FWL). Immersion-type experiments are performed for comparison; the dominant recovery mechanism changed from co-current to counter-current imbibition when the boundary conditions changed from advancing FWL to immersion-type. Single block experiments of co-current and counter-current imbibition was performed and co-current imbibition leads to more efficient recovery was found.

  4. SCF(JFK) is a bona fide E3 ligase for ING4 and a potent promoter of the angiogenesis and metastasis of breast cancer.

    Science.gov (United States)

    Yan, Ruorong; He, Lin; Li, Zhongwu; Han, Xiao; Liang, Jing; Si, Wenzhe; Chen, Zhe; Li, Lei; Xie, Guojia; Li, Wanjin; Wang, Peiyan; Lei, Liandi; Zhang, Hongquan; Pei, Fei; Cao, Dengfeng; Sun, Luyang; Shang, Yongfeng

    2015-03-15

    Loss of function/dysregulation of inhibitor of growth 4 (ING4) and hyperactivation of NF-κB are frequent events in many types of human malignancies. However, the molecular mechanisms underlying these remarkable aberrations are not understood. Here, we report that ING4 is physically associated with JFK. We demonstrated that JFK targets ING4 for ubiquitination and degradation through assembly of an Skp1-Cul1-F-box (SCF) complex. We showed that JFK-mediated ING4 destabilization leads to the hyperactivation of the canonical NF-κB pathway and promotes angiogenesis and metastasis of breast cancer. Significantly, the expression of JFK is markedly up-regulated in breast cancer, and the level of JFK is negatively correlated with that of ING4 and positively correlated with an aggressive clinical behavior of breast carcinomas. Our study identified SCF(JFK) as a bona fide E3 ligase for ING4 and unraveled the JFK-ING4-NF-κB axis as an important player in the development and progression of breast cancer, supporting the pursuit of JFK as a potential target for breast cancer intervention.

  5. Fracture mechanics

    CERN Document Server

    Perez, Nestor

    2017-01-01

    The second edition of this textbook includes a refined presentation of concepts in each chapter, additional examples; new problems and sections, such as conformal mapping and mechanical behavior of wood; while retaining all the features of the original book. The material included in this book is based upon the development of analytical and numerical procedures pertinent to particular fields of linear elastic fracture mechanics (LEFM) and plastic fracture mechanics (PFM), including mixed-mode-loading interaction. The mathematical approach undertaken herein is coupled with a brief review of several fracture theories available in cited references, along with many color images and figures. Dynamic fracture mechanics is included through the field of fatigue and Charpy impact testing. Explains computational and engineering approaches for solving crack-related problems using straightforward mathematics that facilitate comprehension of the physical meaning of crack growth processes; Expands computational understandin...

  6. Fracture mechanics

    Science.gov (United States)

    Shannon, John L., Jr.

    1986-01-01

    The application of fracture mechanics to the design of ceramic structures will require the precise measurement of crack growth and fracture resistance of these materials over their entire range of anticipated service temperatures and standardized test methods for making such measurements. The development of a standard test for measuring the plane strain fracture toughness is sought. Stress intensity factor coefficients were determined for three varieties of chevron-notch specimens, and fracture toughness measurements were made on silicon nitrides, silicon carbides, and aluminum oxides to assess the performance of each specimen variety. It was determined that silicon nitride and silicon carbides have flat crack growth resistance curves, but aluminum oxide does not. Additionally, batch-to-batch differences were noticed for the aluminum oxide. Experiments are continuing to explain the rising crack growth resistance and batch-to-batch variations for the aluminum oxide.

  7. IMAGING DIAGNOSIS OF THORACOLUMBAR BURST FRACTURES

    Institute of Scientific and Technical Information of China (English)

    Li-yang Dai

    2004-01-01

    Objective To review imaging use in the diagnosis ofthoracolumbar burst fractures and to determine the diagnostic value of different imaging methods.Methods One hundred and fourteen patients with 120 thoracolumbar burst fractures were retrospectively reviewed. Plain radiographs were available in all cases; CT scans and MRI were obtained in 96 and 74 cases, respectively.Results A total of 27 burst fractures were misdiagnosed as other types of fractures on radiographs alone, and accounted for 22.5% of all fractures. The results indicated that plain radiographs often fail to delineate the pathological features of thoracolumbar burst fractures, leading to delay in diagnosis.Conclusion In regard to thoracolumbar injury diagnosis, burst fractures should be differentiated from compression fractures. CT should be routinely indicated and MRI examination, when necessary, may be simultaneously considered.

  8. An Unusual Combination of Acetabular and Pelvic Fracture: Is This a New Subtype of Acetabular Fracture?

    Directory of Open Access Journals (Sweden)

    Reza Tavakoli Darestani

    2013-01-01

    Full Text Available Introduction: Acetabular fractures are a common problem among young males. An acetabular fracture with disruption of the joint surface, if untreated, will rapidly lead to post-traumatic osteoarthritis. Proper reduction and internal fixation depend on accurate classification and the quality of imaging.Case Presentation: We present an unusual form of acetabular fracture, which is not included in the conventional classification (Judet and Letournel ; this occurred in a middle-aged male who was operatively treated without any complications. In this case due to posterior extension of the fracture into the SI joint and concomitant anterior column fracture in the area above the acetabular dome, no portion of the acetabular anterior surface remained connected to the innominate bone.Conclusions: We recognized this type of fracture and treated it similarly to both column fractures. We recommend that the classification of acetabular fractures be modified to include this type of fracture.

  9. Physical chemistry of glass fracture

    Energy Technology Data Exchange (ETDEWEB)

    Michalske, T.A. [Sandia National Laboratories, Albuquerque, NM (United States)

    1993-12-31

    Since silica glass is a brittle material, its susceptibility to fracture often limits its use in technological applications. Previous studies have demonstrated that the fracture resistance of silica glass is decreased greatly by the presence of chemically reactive species such as water. By studying the effect of controlled amounts of reactive gases on the fracture rate in silica glass, the authors have developed chemical kinetics based models to describe the molecular level processes that lead to stress corrosion fracture of glass. A key aspect of our chemical kinetics based model is the measurement of the stress dependence for the hydrolysis of siloxane bonds. The authors derive the stress dependence for hydrolysis from reaction rate studies that are conducted on strained cyclosiloxane model compounds. The chemical kinetic parameter derived from model compounds is used to successfully predict the fracture behavior of bulk silica glass and the mechanical fatigue of high-strength silica glass fibers in various reactive chemical environments.

  10. Anterior internal fixation to treat vertical unstable pelvic fracture

    Institute of Scientific and Technical Information of China (English)

    王世松; 张鹏程; 杜敦进; 杨泗华

    2002-01-01

    With the Chinese development of industry, agriculture and communication, various traffic and work related accidents are increasing, leading to an increase in pelvic fractures. Among the different kinds of fractures, pelvic fracture is the third largest cause of death.1 The treatment of pelvic fractures is a “hot spot” and a difficult point in orthopedic surgery. Since 1998 we have treated 20 patients with vertical unstable pelvic fracture using anterior internal fixation. Satisfactory results have been obtained.

  11. A Resource for the Transcriptional Signature of Bona Fide Trophoblast Stem Cells and Analysis of Their Embryonic Persistence

    Directory of Open Access Journals (Sweden)

    Georg Kuales

    2015-01-01

    Full Text Available Trophoblast stem cells (TSCs represent the multipotent progenitors that give rise to the different cells of the embryonic portion of the placenta. Here, we analysed the expression of key TSC transcription factors Cdx2, Eomes, and Elf5 in the early developing placenta of mouse embryos and in cultured TSCs and reveal surprising heterogeneity in protein levels. We analysed persistence of TSCs in the early placenta and find that TSCs remain in the chorionic hinge until E9.5 and are lost shortly afterwards. To define the transcriptional signature of bona fide TSCs, we used inducible gain- and loss-of-function alleles of Eomes or Cdx2, and EomesGFP, to manipulate and monitor the core maintenance factors of TSCs, followed by genome-wide expression profiling. Combinatorial analysis of resulting expression profiles allowed for defining novel TSC marker genes that might functionally contribute to the maintenance of the TSC state. Analyses by qRT-PCR and in situ hybridisation validated novel TSC- and chorion-specific marker genes, such as Bok/Mtd, Cldn26, Duox2, Duoxa2, Nr0b1, and Sox21. Thus, these expression data provide a valuable resource for the transcriptional signature of bona fide and early differentiating TSCs and may contribute to an increased understanding of the transcriptional circuitries that maintain and/or establish stemness of TSCs.

  12. Effects of fracture reactivation and diagenesis on fracture network evolution: Cambrian Eriboll Formation, NW Scotland

    Science.gov (United States)

    Hooker, J. N.; Eichhubl, P.; Xu, G.; Ahn, H.; Fall, A.; Hargrove, P.; Laubach, S.; Ukar, E.

    2011-12-01

    , new, more favorably oriented slip surfaces form while earlier formed slip surfaces become inactive and cemented. This interaction between mechanical processes of fault-fracture network evolution with cementation leads to complex fault systems with heterogeneous permeability structure.

  13. Gravity-Driven Hydraulic Fractures

    Science.gov (United States)

    Germanovich, L. N.; Garagash, D.; Murdoch, L. C.; Robinowitz, M.

    2014-12-01

    This study is motived by a new method for disposing of nuclear waste by injecting it as a dense slurry into a hydraulic fracture that grows downward to great enough depth to permanently isolate the waste. Disposing of nuclear waste using gravity-driven hydraulic fractures is mechanically similar to the upward growth of dikes filled with low density magma. A fundamental question in both applications is how the injected fluid controls the propagation dynamics and fracture geometry (depth and breadth) in three dimensions. Analog experiments in gelatin [e.g., Heimpel and Olson, 1994; Taisne and Tait, 2009] show that fracture breadth (the short horizontal dimension) remains nearly stationary when the process in the fracture "head" (where breadth is controlled) is dominated by solid toughness, whereas viscous fluid dissipation is dominant in the fracture tail. We model propagation of the resulting gravity-driven (buoyant or sinking), finger-like fracture of stationary breadth with slowly varying opening along the crack length. The elastic response to fluid loading in a horizontal cross-section is local and can be treated similar to the classical Perkins-Kern-Nordgren (PKN) model of hydraulic fracturing. The propagation condition for a finger-like crack is based on balancing the global energy release rate due to a unit crack extension with the rock fracture toughness. It allows us to relate the net fluid pressure at the tip to the fracture breadth and rock toughness. Unlike the PKN fracture, where breadth is known a priori, the final breadth of a finger-like fracture is a result of processes in the fracture head. Because the head is much more open than the tail, viscous pressure drop in the head can be neglected leading to a 3D analog of Weertman's hydrostatic pulse. This requires relaxing the local elasticity assumption of the PKN model in the fracture head. As a result, we resolve the breadth, and then match the viscosity-dominated tail with the 3-D, toughness

  14. Galeazzi fracture.

    Science.gov (United States)

    Atesok, Kivanc I; Jupiter, Jesse B; Weiss, Arnold-Peter C

    2011-10-01

    Galeazzi fracture is a fracture of the radial diaphysis with disruption at the distal radioulnar joint (DRUJ). Typically, the mechanism of injury is forceful axial loading and torsion of the forearm. Diagnosis is established on radiographic evaluation. Underdiagnosis is common because disruption of the ligamentous restraints of the DRUJ may be overlooked. Nonsurgical management with anatomic reduction and immobilization in a long-arm cast has been successful in children. In adults, nonsurgical treatment typically fails because of deforming forces acting on the distal radius and DRUJ. Open reduction and internal fixation is the preferred surgical option. Anatomic reduction and rigid fixation should be followed by intraoperative assessment of the DRUJ. Further intraoperative interventions are based on the reducibility and postreduction stability of the DRUJ. Misdiagnosis or inadequate management of Galeazzi fracture may result in disabling complications, such as DRUJ instability, malunion, limited forearm range of motion, chronic wrist pain, and osteoarthritis.

  15. When do fractured media become seismically anisotropic? Some implications on quantifying fracture properties

    Science.gov (United States)

    Yousef, B. M.; Angus, D. A.

    2016-06-01

    Fractures are pervasive features within the Earth's crust and they have a significant influence on the multi-physical response of the subsurface. The presence of coherent fracture sets often leads to observable seismic anisotropy enabling seismic techniques to remotely locate and characterise fracture systems. In this study, we confirm the general scale-dependence of seismic anisotropy and provide new results specific to shear-wave splitting (SWS). We find that SWS develops under conditions when the ratio of wavelength to fracture size (λS / d) is greater than 3, where Rayleigh scattering from coherent fractures leads to an effective anisotropy such that effective medium model (EMM) theory is qualitatively valid. When 1 scattering, where no effective anisotropy develops and hence the SWS measurements are unstable. When λS / d scattering and begin to see behaviour similar to transverse isotropy. We find that seismic anisotropy is more sensitive to fracture density than fracture compliance ratio. More importantly, we observe that the transition from scattering to an effective anisotropic regime occurs over a propagation distance between 1 and 2 wavelengths depending on the fracture density and compliance ratio. The existence of a transition zone means that inversion of seismic anisotropy parameters based on EMM will be fundamentally biased. More importantly, we observe that linear slip EMM commonly used in inverting fracture properties is inconsistent with our results and leads to errors of approximately 400% in fracture spacing (equivalent to fracture density) and 60% in fracture compliance. Although EMM representations can yield reliable estimates of fracture orientation and spatial location, our results show that EMM representations will systematically fail in providing quantitatively accurate estimates of other physical fracture properties, such as fracture density and compliance. Thus more robust and accurate quantitative estimates of in situ fracture

  16. Fracture Blisters

    Directory of Open Access Journals (Sweden)

    Uebbing, Claire M

    2011-02-01

    Full Text Available Fracture blisters are a relatively uncommon complication of fractures in locations of the body, such as the ankle, wrist elbow and foot, where skin adheres tightly to bone with little subcutaneous fat cushioning. The blister that results resembles that of a second degree burn.These blisters significantly alter treatment, making it difficult to splint or cast and often overlying ideal surgical incision sites. Review of the literature reveals no consensus on management; however, most authors agree on early treatment prior to blister formation or delay until blister resolution before attempting surgical correction or stabilization. [West J Emerg Med. 2011;12(1;131-133.

  17. Interpretation of stress damage on fracture conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Berumen, Sergio; Tiab, Djebbar [PEMEX E and P and The University of Oklahoma, School of Petroleum and Geological Engineering, Norman, OK (United States)

    1997-02-01

    This paper focuses on the investigation of pressure responses in a well producing through a composite system of a stress-sensitive vertical symmetric or asymmetric fracture interacting with a stress-sensitive permeable-porous medium. Results of this investigation demonstrate that when the fracture conductivity is stress dependent, the use of conventional techniques to evaluate fractured wells may lead to incorrect estimates of the fracture-formation properties. For finite conductivity fractures, the stress effects in the formation have a negligible influence on the absolute value of the slope that defines the pseudo-bilinear flow regime. During this flow regime only the pressure sensitivity in the fracture and the fracture conductivity govern this flow period. For cases that involve highly conductive fractures, it was found that the slope of 0.5 which defines the linear flow regime is not influenced by the stress effect of the fracture and formation. However, stress in highly conductive fractures has a measurable influence in the change of conductivity. The occurrence of the stress damage in finite and infinite conductivity fractures is due to the partial closure fracture or partial choke fracture effect and can be anticipated in terms of pressure or time level by using the equations provided in this work. The results derived from this research have a major impact in improving the analysis of fractured wells pressure responses, as well as in forecasting of fracture closure occurrence and in programming stimulation operations in fractured wells. An example with synthetic data is presented to illustrate these new findings

  18. Neglected hangman fracture

    Directory of Open Access Journals (Sweden)

    Sudhir Kumar Srivastava

    2015-01-01

    Full Text Available Acute management of hangman fracture is well described; however the surgical management of neglected hangman fracture has not been described in literature. We report the surgical management of an untreated hangman′s fracture. A 30-year-old male had fallen from a tree 12 weeks back. Patient presented with cervical myelopathy and restricted neck movements. Radiographs and computed tomography (CT scan revealed fracture of pars interarticularis of axis with Grade III C2-C3 spondylolisthesis with localized kyphosis of 33°. Gentle reduction under general anesthesia (GA failed to improve the alignment. Patient was operated in three stages in a single setting. In Stage I, release of contracted anterior structures and C2-C3 discectomy was done in supine position followed by C2-C3 posterior fixation and fusion in Stage II. C2-C3 interbody bone grafting and anterior plating completed the third stage. C2-C3 interbody fusion was seen at 5 months and a CT scan at 18 months postoperative confirmed fusion and maintenance of alignment. The satisfactory outcome in our patient leads us to believe that anterior-posterior-anterior is the appropriate surgical approach for treatment of such patients.

  19. Discrete fracture modeling of multiphase flow and hydrocarbon production in fractured shale or low permeability reservoirs

    Science.gov (United States)

    Hao, Y.; Settgast, R. R.; Fu, P.; Tompson, A. F. B.; Morris, J.; Ryerson, F. J.

    2016-12-01

    It has long been recognized that multiphase flow and transport in fractured porous media is very important for various subsurface applications. Hydrocarbon fluid flow and production from hydraulically fractured shale reservoirs is an important and complicated example of multiphase flow in fractured formations. The combination of horizontal drilling and hydraulic fracturing is able to create extensive fracture networks in low permeability shale rocks, leading to increased formation permeability and enhanced hydrocarbon production. However, unconventional wells experience a much faster production decline than conventional hydrocarbon recovery. Maintaining sustainable and economically viable shale gas/oil production requires additional wells and re-fracturing. Excessive fracturing fluid loss during hydraulic fracturing operations may also drive up operation costs and raise potential environmental concerns. Understanding and modeling processes that contribute to decreasing productivity and fracturing fluid loss represent a critical component for unconventional hydrocarbon recovery analysis. Towards this effort we develop a discrete fracture model (DFM) in GEOS (LLNL multi-physics computational code) to simulate multiphase flow and transfer in hydraulically fractured reservoirs. The DFM model is able to explicitly account for both individual fractures and their surrounding rocks, therefore allowing for an accurate prediction of impacts of fracture-matrix interactions on hydrocarbon production. We apply the DFM model to simulate three-phase (water, oil, and gas) flow behaviors in fractured shale rocks as a result of different hydraulic stimulation scenarios. Numerical results show that multiphase flow behaviors at the fracture-matrix interface play a major role in controlling both hydrocarbon production and fracturing fluid recovery rates. The DFM model developed in this study will be coupled with the existing hydro-fracture model to provide a fully integrated

  20. Hand Fractures

    Science.gov (United States)

    ... Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is ... serve as a framework. This framework supports the muscles that make the wrist ... When one of these hand bones is broken (fractured), it can prevent you ...

  1. Fracture source

    Directory of Open Access Journals (Sweden)

    2003-07-01

    Full Text Available The fracture properties of many different types of fibers are covered in a timely new book that will prove to be a tremendous source of information and references for researchers in the wide and diverse field of fibers and composites, says Bill Clegg.

  2. Rib Fractures

    Science.gov (United States)

    ... Commentary Recent News Scientists Working on Solar-Powered Prosthetic Limbs Exercise a Great Prescription to Help Older Hearts Bavencio Approved for Rare Skin Cancer Older Mothers May Raise Better-Behaved Kids, Study ... or a collapsed lung (pneumothorax—see Traumatic Pneumothorax ). An injury that fractures the lower ribs sometimes also damages the liver (see Liver ...

  3. [Thoracolumbar fractures].

    Science.gov (United States)

    Freslon, M; Bouaka, D; Coipeau, P; Defossez, G; Leclercq, N; Nebout, J; Marteau, E; Poilbout, N; Prebet, R

    2008-06-01

    Thoracolumbar fractures are frequent and the functional outcomes are sometimes severe. This multicentric study, including five medical centers, was performed to evaluate the long-term outcomes of the patients. One hundred and thirty six patients with thoracolumbar fracture (T11 to L2) was evaluated with a minimal follow-up of two years. Every one had a clinical exam with a score of Oswestry and an X-Ray study (before and after treatment and at revision). Most of them presented compression fractures, the most often at L1 level. On X-rays, a gain was noted on the vertebral kyphosis immediately after surgery, but there is a loss of correction over time whatever the treatment. The clinical outcomes for the patients were great, with an Oswestry average score of 6,4. A correlation was noted between this functional score and vertebral kyphosis. So, an anterior column strengthening (isolated or performed during the surgery) could improve these functional outcomes. Moreover, the Thoraco Lumbar Injury Severity Score (TLISS) seems to be a simple organigram to determine the most appropriate treatment of these fractures, with particular attention to the distraction mechanism or posterior ligamentous complex lesions. However, RMI before surgery is necessary to evaluate these lesions.

  4. Educar para corregir una actitud de los universitarios: el fideísmo Educar para corrigir uma atitude de faculdade: o fideísmo Education to Correct an Attitude among University Students and Teachers: Fideism

    Directory of Open Access Journals (Sweden)

    Juan Fernando Selles

    2009-12-01

    Full Text Available En este trabajo se desvela el error de una actitud educativa que acepta taimadamente el "fideísmo": actitud que afecta a muchos universitarios -docentes y discentes- que quieren ser y se consideran a sí mismos como hombres "buenos". Se describe la índole de este yerro, así como algunas de sus usuales manifestaciones universitarias. Se indica que no es una actitud natural humana ni tampoco cristiana, pues es contraria tanto a la razón natural como a la doctrina de la fe. Al final se ofrecen algunas pautas para hacer frente a esta desorientación educativa.Este artigo se revela o erro de uma atitude educativa que dissimuladamente aceita o fideísmo: esta "atitude" afeta a muitos universitários (professores e alunos que querem ser homens "bons" e se consideram como tais. Descreve-se a natureza deste erro e algumas das suas manifestações freqüentes. Afirma-se que não é uma atitude natural do ser humano, nem do cristão, porque é contrária tanto à razão natural e à doutrina da fé. No final se oferecem algumas diretrizes para resolver esta falta de orientação educacional.The article exposes an educational attitude that stubbornly accepts "fideism": an attitude found among many university teachers and students who want to be and regard themselves as "good" men and women. The nature of this error is described, along with some of its more common manifestations in the university environment. Fideism is cited as being neither a natural human attitude, nor a Christian attitude. It is contrary to both natural reasoning and the doctrine of the faith. The article ends with several guidelines on how to deal with this educational disorientation.

  5. Study of the morphology and biomechanics of sacral fracture

    Institute of Scientific and Technical Information of China (English)

    QUAN Ren-fu; YANG Di-sheng; WANG Yi-jin

    2006-01-01

    Objective: To observe the morphological characteristics of sacral fracture under different impact loads.Method: Ten fresh pelvic specimens were loaded in dynamic or static state. A series of mechanical parameters including the pressure strain and velocity were recorded.Morphological characteristics were observed under scanning electron microscope.Results: The form of sacral fracture was related to the impact energy. Under low-energy impact loads, ilium fracture, acetabulum fracture and crista iliaca fracture were found. Under high-energy impact loads, three types of sacral fracture occurred according to the classification of Denis: sacral ala fracture, Type Ⅰ fracture; sacral foramen cataclasm fracture, Type Ⅱ fracture; central vertebral canal fracture, Type Ⅲ fracture. Nerve injury of one or two sides was involved in all three types of sacral fracture.The fracture mechanism of sacrum between the dynamic impact and static compression was significantly different.When the impact energy was above 25 J, sacral foramen cataclasm fracture occurred, involving nerve root injury.When it was below 20 J, ilium and sacral fracture was most likely to occur. When it was 20 ~ 25 J, Type Ⅰ fracture would occur. While in the static test, most of the fracture belonged to ilium or acetabulum fracture. The cross section of sacrum was crackly and the bone board of Haversian system was brittle, which could lead to separation of bone boards and malposition of a few of cross bone boards.Conclusions: In dynamic state, sacrum fracture mostly belongs to Type Ⅰ and Type Ⅱ, and usually involves the nerve roots. Sacrum fracture is relevant to the microstructures, the distribution of the bone trabecula, the osseous lacuna and the Haversian system of sacrum. The fracture of ilium and acetabulum more frequently appears in static state, with slight wound of peripheral tissues.

  6. Anterior fracture dislocation of sacroiliac joint: A rare type of crescent fracture

    Directory of Open Access Journals (Sweden)

    Vivek Trikha

    2015-01-01

    Full Text Available Crescent fractures of the pelvis are usually described as posterior sacro iliac fracture dislocations. Rarely anterior displacement of the fractured iliac fragment along with dislocation has been reported in crescent fractures. Four cases of anterior fracture dislocation of the sacro iliac joint managed in the last two years by a single surgeon are presented. The injury mechanism, radiological diagnosis, management protocol along with functional outcomes of all the four patients have been discussed. CT scan is essential in the diagnosis and preoperative planning of this injury pattern. Early fixation along with proper reduction leads to excellent functional outcome in this subset of lateral compression injuries of the pelvis.

  7. Fluid Compressibility Effects during Hydraulic Fracture: an Opportunity for Gas Fracture Revival

    Science.gov (United States)

    Mighani, S.; Boulenouar, A.; Moradian, Z.; Evans, J. B.; Bernabe, Y.

    2015-12-01

    Hydraulic fracturing results when internal pore pressure is increased above a critical value. As the fracture extends, the fluid flows to the crack tip. The fracturing process depends strongly on the physical properties of both the porous solid and the fluid (e.g. porosity and elastic moduli for the solid, viscosity and compressibility for the fluid). It is also affected by the in-situ stress and pore pressure conditions. Here, we focus on the effect of fluid properties on hydraulic fracturing under conventional triaxial loading. Cylinders of Solnhofen limestone (a fine-grained, low permeability rock) were prepared with a central borehole through which different pressurized fluids such as oil, water or argon, were introduced. Preliminary experiments were performed using a confining pressure of 5 MPa and axial stress of 7 MPa. Our goal was to monitor fracture extension using strain gauges, acoustic emissions (AE) recording and ultrasonic velocity measurements. We also tried to compare the data with analytical models of fracture propagation. Initial tests showed that simple bi-wing fractures form when the fracturing fluid is relatively incompressible. With argon as pore fluid, a complex fracture network was formed. We also observed that the breakdown pressure was higher with argon than with less compressible fluids. After fracturing occurred, we cycled fluid pressure for several times. During the first cycles, re-opening of the fracture was associated with additional propagation. In general, it took 4 cycles to inhibit further propagation. Analytical models suggest that initial fractures occurring with compressible fluids tend to stabilize. Hence, formation and extension of additional fractures may occur, leading to a more complex morphology. Conversely, fractures formed by incompressible fluids remain critically stressed as they extend, thus producing a simple bi-wing fracture. Using compressible fracturing fluids could be a suitable candidate for an efficient

  8. Postmenopausal osteoporosis: fracture risk and prevention.

    Science.gov (United States)

    Kaunitz, Andrew M; McClung, Michael R; Feldman, Robert G; Wysocki, Susan

    2009-11-01

    In the estrogen-regulated RANK ligand (RANKL)/RANK/osteoprotegerin (OPG) pathway, estrogen deficiency favors osteoclast maturation, leading to increased bone resorption compared with bone formation. Treatment of low bone mineral density (BMD) should be based on fracture risk, assessed using the WHO Fracture Risk Algorithm (FRAX(R)). Criteria for treatment are 10-year overall fracture risk ≥ 20% or 10-year hip fracture risk ≥ 3%. Vitamin D supplementation at levels higher than those traditionally recommended may be appropriate for healthy menopausal women. Multiple strategies are needed to effectively manage osteoporosis in postmenopausal women.

  9. Seizure-induced muscle force can caused lumbar spine fracture

    DEFF Research Database (Denmark)

    Mehlhorn, A T; Strohm, P C; Hausschildt, O;

    2007-01-01

    Patients suffering form epilepsy have an increased risk for fractures. Beside fractures caused by fall or accident muscles forces alone generated during tonic-clonic seizure can result in severe musculoskeletal injury. Contractions of strong paraspinal muscles can lead to compression fracture of ...

  10. Intelligent fracture creation for shale gas development

    KAUST Repository

    Douglas, Craig C.

    2011-05-14

    Shale gas represents a major fraction of the proven reserves of natural gas in the United States and a collection of other countries. Higher gas prices and the need for cleaner fuels provides motivation for commercializing shale gas deposits even though the cost is substantially higher than traditional gas deposits. Recent advances in horizontal drilling and multistage hydraulic fracturing, which dramatically lower costs of developing shale gas fields, are key to renewed interest in shale gas deposits. Hydraulically induced fractures are quite complex in shale gas reservoirs. Massive, multistage, multiple cluster treatments lead to fractures that interact with existing fractures (whether natural or induced earlier). A dynamic approach to the fracturing process so that the resulting network of reservoirs is known during the drilling and fracturing process is economically enticing. The process needs to be automatic and done in faster than real-time in order to be useful to the drilling crews.

  11. Meshless Animation of Fracturing Solids

    Science.gov (United States)

    Pauly, Mark; Keiser, Richard; Adams, Bart; Dutré, Philip; Gross, Markus; Guibas, Leonidas J.

    2010-01-01

    We present a new meshless animation framework for elastic and plastic materials that fracture. Central to our method is a highly dynamic surface and volume sampling method that supports arbitrary crack initiation, propagation, and termination, while avoiding many of the stability problems of traditional mesh-based techniques. We explicitly model advancing crack fronts and associated fracture surfaces embedded in the simulation volume. When cutting through the material, crack fronts directly affect the coupling between simulation nodes, requiring a dynamic adaptation of the nodal shape functions. We show how local visibility tests and dynamic caching lead to an efficient implementation of these effects based on point collocation. Complex fracture patterns of interacting and branching cracks are handled using a small set of topological operations for splitting, merging, and terminating crack fronts. This allows continuous propagation of cracks with highly detailed fracture surfaces, independent of the spatial resolution of the simulation nodes, and provides effective mechanisms for controlling fracture paths. We demonstrate our method for a wide range of materials, from stiff elastic to highly plastic objects that exhibit brittle and/or ductile fracture. PMID:21165160

  12. Growth Plate Fractures

    Science.gov (United States)

    ... the most widely used by doctors is the Salter-Harris system, described below. Type I Fractures These ... incidence of growth plate fractures peaks in adolescence. Salter-Harris classification of growth plate fractures. AAOS does ...

  13. For the first fracture to be the last

    Directory of Open Access Journals (Sweden)

    Bernardo Stolnicki

    2016-04-01

    Full Text Available Increased longevity has made progression in the number of fractures increasingly significant. Because hip fractures give rise to high morbidity and mortality rates and have high treatment costs, their occurrence is the most important marker of effectiveness in relation to osteoporosis treatment. In countries and systems that, especially over the last decade, have been investing in the prevention of osteoporosis and its consequences, the number of hip fractures has been decreasing. What these countries have in common is secondary prevention of fractures, i.e. to avoid subsequent fractures. Given that half of the patients who present hip fractures have had a previous fracture and that the treatments available have proven to be extremely efficient for decreasing subsequent fractures, a good proportion of hip fractures are preventable. It is within this scenario that orthopedists play a leading role.

  14. For the first fracture to be the last

    Science.gov (United States)

    Stolnicki, Bernardo; Oliveira, Lindomar Guimarães

    2016-01-01

    Increased longevity has made progression in the number of fractures increasingly significant. Because hip fractures give rise to high morbidity and mortality rates and have high treatment costs, their occurrence is the most important marker of effectiveness in relation to osteoporosis treatment. In countries and systems that, especially over the last decade, have been investing in the prevention of osteoporosis and its consequences, the number of hip fractures has been decreasing. What these countries have in common is secondary prevention of fractures, i.e. to avoid subsequent fractures. Given that half of the patients who present hip fractures have had a previous fracture and that the treatments available have proven to be extremely efficient for decreasing subsequent fractures, a good proportion of hip fractures are preventable. It is within this scenario that orthopedists play a leading role. PMID:27069877

  15. Delayed ICD lead cardiac perforation: comparison of small versus standard-diameter leads implanted in a single center.

    Science.gov (United States)

    Rordorf, Roberto; Canevese, Fabio; Vicentini, Alessandro; Petracci, Barbara; Savastano, Simone; Sanzo, Antonio; Gandolfi, Edoardo; Dore, Roberto; Landolina, Maurizio

    2011-04-01

    An increased risk of delayed cardiac perforation (DCP) with active-fixation small-diameter ICD leads has recently been reported, especially with regard to the St. Jude Riata lead (St. Jude Medical, Sylmar, CA, USA). Few data on the risk of DCP in small versus standard-diameter leads implanted in a single high-volume center are available. Moreover, no data on the performances of St. Jude's new small-diameter Durata lead are as yet available. The aim of this study was to assess the incidence of DCP in small versus standard-diameter leads implanted in our center. Between January 2003 and October 2009, 437 small-diameter leads (190 Medtronic Sprint Fidelis [Medtronic Inc., Minneapolis, MN, USA], 196 Riata, 51 Durata) and 421 standard-diameter (>8 Fr) leads were implanted. After a median follow-up of 421 days seven of 858 (0.8%) patients experienced DCP. The incidence of DCP was higher in patients with small-diameter leads than in those with standard-diameter leads (1.6% vs 0%, P = 0.01). No cases of DCP occurred among 371 passive-fixation leads versus 1.4% of events among active-fixation leads (P = 0.02). The incidence of DCP was 2.5% in Riata, 1% in Sprint Fidelis, 0% in Durata, and 0% in standard-diameter leads (P < 0.01 for Riata vs standard-diameter leads). Small-diameter active-fixation ICD leads are at increased risk of DCP, a finding mostly due to the higher incidence of events in the Riata family. By contrast, passive-fixation small-diameter leads and standard-diameter leads appear to be safe enough regarding the risk of DCP. Our preliminary data suggest that the new Durata lead is not associated with an increased risk of DCP. ©2010, The Authors. Journal compilation ©2010 Wiley Periodicals, Inc.

  16. Acidization of shales with calcite cemented fractures

    Science.gov (United States)

    Kwiatkowski, Kamil; Szymczak, Piotr; Jarosiński, Marek

    2017-04-01

    Investigation of cores drilled from shale formations reveals a relatively large number of calcite-cemented fractures. Usually such fractures are reactivated during fracking and can contribute considerably to the permeability of the resulting fracture network. However, calcite coating on their surfaces effectively excludes them from production. Dissolution of the calcite cement by acidic fluids is investigated numerically with focus on the evolution of fracture morphology. Available surface area, breakthrough time, and reactant penetration length are calculated. Natural fractures in cores from Pomeranian shale formation (northern Poland) were analyzed and classified. Representative fractures are relatively thin (0.1 mm), flat and completely sealed with calcite. Next, the morphology evolution of reactivated natural fractures treated with low-pH fluids has been simulated numerically under various operating conditions. Depth-averaged equations for fracture flow and reactant transport has been solved by finite-difference method coupled with sparse-matrix solver. Transport-limited dissolution has been considered, which corresponds to the treatment with strong acids, such as HCl. Calcite coating in reactivated natural fractures dissolves in a highly non-homogeneous manner - a positive feedback between fluid transport and calcite dissolution leads to the spontaneous formation of wormhole-like patterns, in which most of the flow is focused. The wormholes carry reactive fluids deeper inside the system, which dramatically increases the range of the treatment. Non-uniformity of the dissolution patterns provides a way of retaining the fracture permeability even in the absence of the proppant, since the less dissolved regions will act as supports to keep more dissolved regions open. Evolution of fracture morphology is shown to depend strongly on the thickness of calcite layer - the thicker the coating the more pronounced wormholes are observed. However the interaction between

  17. Chopart fractures.

    Science.gov (United States)

    Klaue, Kaj

    2004-09-01

    The Chopart articular space was described by François Chopart (1743-1795) as a practical space for amputations in cases of distal foot necrosis. It corresponds to the limit between the anatomical hind-foot and the mid-foot. The bones involved are the talus and the calcaneus proximally, and the navicular and the cuboid distally. This space thus holds two functionally distinct entities, the anterior part of the coxa pedis (an essential functional joint) and the calcaneo-cuboidal joint,which can be considered to be an "adaptive joint" within a normal foot. Trauma to this region may cause fractures and/or dislocations and, in high energy trauma,compartment syndromes. Principles of treatment are immediate reduction of dislocations and realignment of the medial and lateral column of the foot in length and orientation. Open reduction and internal fixation of talus and navicular fractures are often indicated to restore the "coxa pedis". Open reconstruction or fusion in correct length of the calcaneo-cuboidal joint is occasionally indicated. Salvage procedures in malunions include navicular osteotomies and calcaneo-cuboidal bone block fusions. Treatment of joint destructions, especially involving the talo-navicular joint, include triple arthrodesis.

  18. [Stress fractures of the distal fibula in an osteoporotic woman].

    Science.gov (United States)

    Schwartz, Frederik; Heerfordt, Ida Marie

    2014-08-04

    We report a case of an 81-year-old osteoporotic woman, who suffered stress fractures of the distal fibula on both sides within a two-year period. The risk factors for stress fractures are reviewed and the importance of a high index of suspicion for stress fractures is emphasized. When a stress fracture is suspected it should lead to plain radiography and treatment with protected weight-bearing with crutches or a brace.

  19. Fractures of the distal radius (Colles' fracture)

    National Research Council Canada - National Science Library

    João Carlos Belloti; João Baptista Gomes dos Santos; Álvaro Nagib Atallah; Walter Manna Albertoni; Flavio Faloppa

    2007-01-01

    CONTEXT AND OBJECTIVE: Although Colles' fracture is a common clinical situation for the orthopedist, we did not find any information in the literature that would allow safe decision-making on the best treatment for each fracture type...

  20. U-shaped sacral fractures: Surgical treatment and quality of life

    NARCIS (Netherlands)

    A.J.G. Gribnau; P. Boele van Hensbroek; R. Haverlag; K.J. Ponsen; H.D. Been; J.C. Goslings

    2009-01-01

    Background: U-shaped sacral fractures are rare and highly unstable pelvic ring fractures. They are not recognised in the standard classification systems of these fractures. The fracture pattern is associated with significant neurological injury and can lead to progressive deformity and chronic pain

  1. Effect of Natural Fractures on Hydraulic Fracturing

    Science.gov (United States)

    Ben, Y.; Wang, Y.; Shi, G.

    2012-12-01

    Hydraulic Fracturing has been used successfully in the oil and gas industry to enhance oil and gas production in the past few decades. Recent years have seen the great development of tight gas, coal bed methane and shale gas. Natural fractures are believed to play an important role in the hydraulic fracturing of such formations. Whether natural fractures can benefit the fracture propagation and enhance final production needs to be studied. Various methods have been used to study the effect of natural fractures on hydraulic fracturing. Discontinuous Deformation Analysis (DDA) is a numerical method which belongs to the family of discrete element methods. In this paper, DDA is coupled with a fluid pipe network model to simulate the pressure response in the formation during hydraulic fracturing. The focus is to study the effect of natural fractures on hydraulic fracturing. In particular, the effect of rock joint properties, joint orientations and rock properties on fracture initiation and propagation will be analyzed. The result shows that DDA is a promising tool to study such complex behavior of rocks. Finally, the advantages of disadvantages of our current model and future research directions will be discussed.

  2. Fracture channel waves

    Science.gov (United States)

    Nihei, Kurt T.; Yi, Weidong; Myer, Larry R.; Cook, Neville G. W.; Schoenberg, Michael

    1999-03-01

    The properties of guided waves which propagate between two parallel fractures are examined. Plane wave analysis is used to obtain a dispersion equation for the velocities of fracture channel waves. Analysis of this equation demonstrates that parallel fractures form an elastic waveguide that supports two symmetric and two antisymmetric dispersive Rayleigh channel waves, each with particle motions and velocities that are sensitive to the normal and tangential stiffnesses of the fractures. These fracture channel waves degenerate to shear waves when the fracture stiffnesses are large, to Rayleigh waves and Rayleigh-Lamb plate waves when the fracture stiffnesses are low, and to fracture interface waves when the fractures are either very closely spaced or widely separated. For intermediate fracture stiffnesses typical of fractured rock masses, fracture channel waves are dispersive and exhibit moderate to strong localization of guided wave energy between the fractures. The existence of these waves is examined using laboratory acoustic measurements on a fractured marble plate. This experiment confirms the distinct particle motion of the fundamental antisymmetric fracture channel wave (A0 mode) and demonstrates the ease with which a fracture channel wave can be generated and detected.

  3. Traumatic thoracolumbar spine fractures

    NARCIS (Netherlands)

    J. Siebenga (Jan)

    2013-01-01

    textabstractTraumatic spinal fractures have the lowest functional outcomes and the lowest rates of return to work after injury of all major organ systems.1 This thesis will cover traumatic thoracolumbar spine fractures and not osteoporotic spine fractures because of the difference in fracture

  4. MR imaging of scaphoid fractures

    DEFF Research Database (Denmark)

    Meincke, Louise; Radev, Dimitar; Eriksen, Rie Østbjerg

    2017-01-01

    Objective: Traumatic injuries of os scaphoideum are serious, and might lead to two main grades of consequences (i.e. osteoarthrosis or avascular necrosis), if a fracture remains undiagnosed. Bone bruise may be the only pathological sign of pain which can last for week or month. Articles describe......). Materials and methods: Two hundred and fifty-one patients with relevant trauma and positive clinical test for scaphoid bone fractures, exceeding no more than 14 days, underwent MRI examinations. A fast STIR and T2 FAT SAT fast spin echo sequence (FSE) were obtained using a comparable parameter setting (scan...... of scaphoid fractures Results: There were no significant difference between the bone bruise areas (P=0.45, P=0.44 and P=0.83) or CNR (P=0.31, P=0.38 and P=0.17). However, image contrast showed significant difference in favour of T2 FAT SAT in all three readers’ reports (P

  5. Assessment of fracture risk

    Energy Technology Data Exchange (ETDEWEB)

    Kanis, John A. [WHO Collaborating Centre for Metabolic Bone Diseases, University of Sheffield Medical School, Beech Hill Road, Sheffield S10 2RX (United Kingdom)], E-mail: w.j.pontefract@sheffield.ac.uk; Johansson, Helena; Oden, Anders [WHO Collaborating Centre for Metabolic Bone Diseases, University of Sheffield Medical School, Beech Hill Road, Sheffield S10 2RX (United Kingdom); McCloskey, Eugene V. [WHO Collaborating Centre for Metabolic Bone Diseases, University of Sheffield Medical School, Beech Hill Road, Sheffield S10 2RX (United Kingdom); Osteoporosis Centre, Northern General Hospital, Sheffield (United Kingdom)

    2009-09-15

    Fractures are a common complication of osteoporosis. Although osteoporosis is defined by bone mineral density at the femoral neck, other sites and validated techniques can be used for fracture prediction. Several clinical risk factors contribute to fracture risk independently of BMD. These include age, prior fragility fracture, smoking, excess alcohol, family history of hip fracture, rheumatoid arthritis and the use of oral glucocorticoids. These risk factors in conjunction with BMD can be integrated to provide estimates of fracture probability using the FRAX tool. Fracture probability rather than BMD alone can be used to fashion strategies for the assessment and treatment of osteoporosis.

  6. A RARE PRESENTATION OF A CONCOMITANT LUMBAR SPINE BURST FRACTURE WITH A DISTAL CORPUS STERNI FRACTURE DUE TO A FLEXION DISTRACTION INJURY

    Directory of Open Access Journals (Sweden)

    Ravi Kumar TV, GadiDaksh, Jain Vinay, Rangaswamy BT

    2015-04-01

    Full Text Available ABSTRACT Sternum fractures are a rare entity and occur either due to direct trauma or indirectly associated to a flexion compression injury. Earlier literatures used to describe the association of sternum fractures with upper thoracic vertebral fractures. To the best of our knowledge very few cases have been described in literature with concomitant lumbar vertebral fracture with associated sternum fracture. We hereby report a rare presentation of a flexion distraction injury leading to a concomitant sternum fracture with a L1 vertebral burst fracture.

  7. XFEM modeling of hydraulic fracture in porous rocks with natural fractures

    Science.gov (United States)

    Wang, Tao; Liu, ZhanLi; Zeng, QingLei; Gao, Yue; Zhuang, Zhuo

    2017-08-01

    Hydraulic fracture (HF) in porous rocks is a complex multi-physics coupling process which involves fluid flow, diffusion and solid deformation. In this paper, the extended finite element method (XFEM) coupling with Biot theory is developed to study the HF in permeable rocks with natural fractures (NFs). In the recent XFEM based computational HF models, the fluid flow in fractures and interstitials of the porous media are mostly solved separately, which brings difficulties in dealing with complex fracture morphology. In our new model the fluid flow is solved in a unified framework by considering the fractures as a kind of special porous media and introducing Poiseuille-type flow inside them instead of Darcy-type flow. The most advantage is that it is very convenient to deal with fluid flow inside the complex fracture network, which is important in shale gas extraction. The weak formulation for the new coupled model is derived based on virtual work principle, which includes the XFEM formulation for multiple fractures and fractures intersection in porous media and finite element formulation for the unified fluid flow. Then the plane strain Kristianovic-Geertsma-de Klerk (KGD) model and the fluid flow inside the fracture network are simulated to validate the accuracy and applicability of this method. The numerical results show that large injection rate, low rock permeability and isotropic in-situ stresses tend to lead to a more uniform and productive fracture network.

  8. Lead Poisoning

    Science.gov (United States)

    Lead is a metal that occurs naturally in the earth's crust. Lead can be found in all parts of our ... from human activities such as mining and manufacturing. Lead used to be in paint; older houses may ...

  9. Practical theology as life science: Fides Quaerens Vivendi and its connection to Hebrew thinking (Hālak

    Directory of Open Access Journals (Sweden)

    Daniël J. Louw

    2017-02-01

    Full Text Available The term practical theology is complex and, due to many different religious and cultural settings, a many layered concept. During the past 40 years the paradigm in theory formation for an academic and disciplinary approach to practical theology shifted from the clerical and ecclesial paradigm of ministerial actions to experiences of faith with the emphasis on an empirical based epistemology. Rather than a deductive approach, the shift is towards a more inductive approach within the methodological framework of phenomenology. Currently, in the international discourse on theory formation, there is a tendency towards a hermeneutical approach with the focus on the networking, relational dynamics of civil society Thus, the attempt to describe practical theology as a kind of ‘life science’ (the concern for the mundane and existential reality of everyday life – Alltagsreligion. Within the context of African spiritualties, with its emphasis on the communal dynamics of vital, human relationships, the focus on lifestyles becomes vital. In light of an ontology of life (l’energie spirituelle – Henri Bergson, the notion of fides quaerens vivendi [faith seeking lifestyles] is researched. With reference to the theory of complexification and chaosmos as well as the impact thereof on different theories in life sciences, the connection between sapientia and the vivid praxis of God is critically explored. The focus of this article is on the question: What is the impact of an ontology of life on both praxis thinking and theological reflection? Instead of the Cartesian framework of causative definitions, the notion of the ‘infinition of God’ is proposed within the praxis of Hebrew, wisdom thinking.

  10. Characterizing drug-metabolizing enzymes and transporters that are bona fide CAR-target genes in mouse intestine

    Directory of Open Access Journals (Sweden)

    Shinhee Park

    2016-09-01

    Full Text Available Intestine is responsible for the biotransformation of many orally-exposed chemicals. The constitutive androstane receptor (CAR/Nr1i3 is known to up-regulate many genes encoding drug-metabolizing enzymes and transporters (drug-processing genes/DPGs in liver, but less is known regarding its effect in intestine. Sixty-day-old wild-type and Car−/− mice were administered the CAR-ligand TCPOBOP or vehicle once daily for 4 days. In wild-type mice, Car mRNA was down-regulated by TCPOBOP in liver and duodenum. Car−/− mice had altered basal intestinal expression of many DPGs in a section-specific manner. Consistent with the liver data (Aleksunes and Klaassen, 2012, TCPOBOP up-regulated many DPGs (Cyp2b10, Cyp3a11, Aldh1a1, Aldh1a7, Gsta1, Gsta4, Gstm1-m4, Gstt1, Ugt1a1, Ugt2b34, Ugt2b36, and Mrp2–4 in specific sections of small intestine in a CAR-dependent manner. However, the mRNAs of Nqo1 and Papss2 were previously known to be up-regulated by TCPOBOP in liver but were not altered in intestine. Interestingly, many known CAR-target genes were highest expressed in colon where CAR is minimally expressed, suggesting that additional regulators are involved in regulating their expression. In conclusion, CAR regulates the basal expression of many DPGs in intestine, and although many hepatic CAR-targeted DPGs were bona fide CAR-targets in intestine, pharmacological activation of CAR in liver and intestine are not identical.

  11. Double segmental tibial fractures——an unusual fracture pattern

    Institute of Scientific and Technical Information of China (English)

    Kamal Bali; Vishal Kumar; Sandeep Patel; Sameer Aggarwal

    2011-01-01

    A case of a 50-year-old pedestrian who was hit by a bike and suffered fractures of both bones of his right leg was presented. Complete clinical and radiographic assessment showed double segmental fractures of the tibia and multisegmental fractures of the fibula. Review of the literature revealed that this fracture pattern was unique and only a single case was reported so far. Moreover, we discussed the possible mechanisms which can lead to such an injury. We also discussed the management of segmental tibial fracture and the difficulties encountered with them. This case was managed by modern osteosynthesis tech nique with a pleasing outcome.

  12. Fracture Criterion for Fracture Mechanics of Magnets

    Institute of Scientific and Technical Information of China (English)

    潘灏; 杨文涛

    2003-01-01

    The applicability and limitation of some fracture criteria in the fracture mechanics of magnets are studied.It is shown that the magnetic field intensity factor can be used as a fracture criterion when the crack in a magnet is only affected by a magnetic field. For some magnetostrictive materials in which the components of magnetostriction strain do not satisfy the compatibility equation of deformation, the stress intensity factor can no longer be effectively applicable as a fracture criterion when the crack in a magnet is affected by a magnetic field and mechanical loads simultaneously.

  13. Scaphoid fractures: what's hot, what's not.

    Science.gov (United States)

    Geissler, William B; Adams, Julie E; Bindra, Randy R; Lanzinger, William D; Slutsky, David J

    2012-01-01

    The scaphoid is the most commonly fractured carpal bone of the wrist. It is an unusual carpal bone in that it bridges both the proximal and the distal rows; this subjects it to continuous shearing and bending forces. Approximately 80% of the scaphoid is covered by cartilage, which limits its ligamentous attachment and vascular supply. Most scaphoid fractures occur at the waist. Acute stable fractures or incomplete fractures of the scaphoid may be treated nonsurgically; a high rate of union can be expected. However, there is considerable debate about the type of immobilization needed. Although closed treatment of stable wrist fractures of the scaphoid achieve a high rate of healing, prolonged cast immobilization may lead to complications, including muscle atrophy, possible joint contracture, and disuse osteopenia. Because of this, internal fixation of minimally displaced fractures of the scaphoid has recently become popular. There is consensus in the literature that nonunion of the scaphoid and proximal pole fractures should be treated surgically. In the past several decades, percutaneous arthroscopic techniques of scaphoid stabilization, which minimize surgical morbidity, have become popular. There also has been a significant improvement in the management of difficult scaphoid nonunions, with or without deformity. Improved techniques include open and dorsal approaches and vascularized bone grafting of resistant scaphoid nonunions. Declining in popularity is the prolonged immobilization of unstable fractures when surgical stabilization may have been a better treatment option.

  14. Lead Toxicity

    Science.gov (United States)

    ... including some imported jewelry. What are the health effects of lead? • More commonly, lower levels of lead in children over time may lead to reduced IQ, slow learning, Attention Deficit Hyperactivity Disorder (ADHD), or behavioral issues. • Lead also affects other ...

  15. Mode I fracture of sheet metal

    Science.gov (United States)

    Pardoen, T.; Hachez, F.; Marchioni, B.; Blyth, P. H.; Atkins, A. G.

    2004-02-01

    The perceived wisdom about thin sheet fracture is that (i) the crack propagates under mixed mode I & III giving rise to a slant through-thickness fracture profile and (ii) the fracture toughness remains constant at low thickness and eventually decreases with increasing thickness. In the present study, fracture tests performed on thin DENT plates of various thicknesses made of stainless steel, mild steel, 6082-O and NS4 aluminium alloys, brass, bronze, lead, and zinc systematically exhibit (i) mode I "bath-tub", i.e. "cup & cup", fracture profiles with limited shear lips and significant localized necking (more than 50% thickness reduction), (ii) a fracture toughness that linearly increases with increasing thickness (in the range of 0.5- 5 mm). The different contributions to the work expended during fracture of these materials are separated based on dimensional considerations. The paper emphasises the two parts of the work spent in the fracture process zone: the necking work and the "fracture" work. Experiments show that, as expected, the work of necking per unit area linearly increases with thickness. For a typical thickness of 1 mm, both fracture and necking contributions have the same order of magnitude in most of the metals investigated. A model is developed in order to independently evaluate the work of necking, which successfully predicts the experimental values. Furthermore, it enables the fracture energy to be derived from tests performed with only one specimen thickness. In a second modelling step, the work of fracture is computed using an enhanced void growth model valid in the quasi plane stress regime. The fracture energy varies linearly with the yield stress and void spacing and is a strong function of the hardening exponent and initial void volume fraction. The coupling of the two models allows the relative contributions of necking versus fracture to be quantified with respect to (i) the two length scales involved in this problem, i.e. the void spacing

  16. The effects of liberal versus restrictive transfusion thresholds on ambulation after hip fracture surgery

    DEFF Research Database (Denmark)

    Foss, Nicolai B; Kristensen, Morten Tange; Jensen, Pia Søe;

    2009-01-01

    BACKGROUND: Perioperative anemia leads to increased morbidity and mortality and potentially inhibits rehabilitation after hip fracture surgery. As such, the optimum transfusion threshold after hip fracture surgery is unknown. PATIENTS AND METHODS: A total of 120 elderly, cognitively intact hip...

  17. Tibia (Shinbone) Shaft Fractures

    Science.gov (United States)

    ... energy collisions, such as an automobile or motorcycle crash, are common causes of tibial sha fractures. In cases like these, the bone can be broken into several pieces (comminuted fracture). Sports injuries, such as a fall while skiing or running ...

  18. Fractures in anisotropic media

    Science.gov (United States)

    Shao, Siyi

    Rocks may be composed of layers and contain fracture sets that cause the hydraulic, mechanical and seismic properties of a rock to be anisotropic. Coexisting fractures and layers in rock give rise to competing mechanisms of anisotropy. For example: (1) at low fracture stiffness, apparent shear-wave anisotropy induced by matrix layering can be masked or enhanced by the presence of a fracture, depending on the fracture orientation with respect to layering, and (2) compressional-wave guided modes generated by parallel fractures can also mask the presence of matrix layerings for particular fracture orientations and fracture specific stiffness. This report focuses on two anisotropic sources that are widely encountered in rock engineering: fractures (mechanical discontinuity) and matrix layering (impedance discontinuity), by investigating: (1) matrix property characterization, i.e., to determine elastic constants in anisotropic solids, (2) interface wave behavior in single-fractured anisotropic media, (3) compressional wave guided modes in parallel-fractured anisotropic media (single fracture orientation) and (4) the elastic response of orthogonal fracture networks. Elastic constants of a medium are required to understand and quantify wave propagation in anisotropic media but are affected by fractures and matrix properties. Experimental observations and analytical analysis demonstrate that behaviors of both fracture interface waves and compressional-wave guided modes for fractures in anisotropic media, are affected by fracture specific stiffness (controlled by external stresses), signal frequency and relative orientation between layerings in the matrix and fractures. A fractured layered medium exhibits: (1) fracture-dominated anisotropy when the fractures are weakly coupled; (2) isotropic behavior when fractures delay waves that are usually fast in a layered medium; and (3) matrix-dominated anisotropy when the fractures are closed and no longer delay the signal. The

  19. Sprains, Strains and Fractures

    Science.gov (United States)

    ... Young Physicians Annual Scientific Meeting Webinars Careers in Podiatry APMA 2040 Student Profiles CPME REdRC Manage Your ... and fractures. Many fractures and sprains occur during sports. Football players are particularly vulnerable to foot and ...

  20. Hip fracture - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000168.htm Hip fracture - discharge To use the sharing features on this page, please enable JavaScript. Hip fracture surgery is done to repair a break in ...

  1. Hip fracture surgery

    Science.gov (United States)

    ... neck fracture repair; Trochanteric fracture repair; Hip pinning surgery; Osteoarthritis - hip ... You may receive general anesthesia for this surgery. This means you ... spinal anesthesia . With this kind of anesthesia, medicine is ...

  2. Metatarsal stress fractures - aftercare

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000553.htm Metatarsal stress fractures - aftercare To use the sharing features on ... that connect your ankle to your toes. A stress fracture is a break in the bone that ...

  3. Periprosthetic acetabular fractures.

    Science.gov (United States)

    Benazzo, Francesco; Formagnana, Mario; Bargagliotti, Marco; Perticarini, Loris

    2015-10-01

    The aim of this article is to propose a diagnostic and therapeutic algorithm for the acetabular periprosthetic fractures. This article explores the current literature on the epidemiology, causes and classification of periprosthetic acetabular fractures. Integrating data with the experience of the authors, it offers a guide to diagnosis and possible therapeutic strategies. Intra-operative fractures can occur during rasping, reaming or implant impaction, and they must be treated immediately if the component(s) is (are) unstable. Post-operative fractures can be due to major trauma (acute fractures) or minor forces in bone osteolysis; it is possible to plan reconstruction and fixation according to fracture characteristics. Treatment choice depends upon fracture site and implant stability. Periprosthetic acetabular fractures are uncommon complications that can occur intra-operatively or post-operatively, and a reconstructive surgeon must be able to manage the procedure. Accurate planning and reconstruction implant are necessary to achieve good cup stability.

  4. Identifying osteoporotic vertebral fracture

    OpenAIRE

    Griffith, James F.

    2015-01-01

    Osteoporosis per se is not a harmful disease. It is the sequela of osteoporosis and most particularly the occurrence of osteoporotic fracture that makes osteoporosis a serious medical condition. All of the preventative measures, investigations, treatment and research into osteoporosis have one primary goal and that is to prevent the occurrence of osteoporotic fracture. Vertebral fracture is by far and away the most prevalent osteoporotic fracture. The significance and diagnosis of vertebral f...

  5. Fracture prevention in men

    NARCIS (Netherlands)

    Geusens, PP; Sambrook, P.N.; Lems, W.F.

    2009-01-01

    The lifetime risk of experiencing a fracture in 50-year-old men is lower (20%) than the risk in women (50%). Consequently, much less research has been carried out on osteoporosis and fracture risk in men. Differences in the risk and incidence of fractures between men and women are related to differe

  6. A Thermoelastic Hydraulic Fracture Design Tool for Geothermal Reservoir Development

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad Ghassemi

    2003-06-30

    Geothermal energy is recovered by circulating water through heat exchange areas within a hot rock mass. Geothermal reservoir rock masses generally consist of igneous and metamorphic rocks that have low matrix permeability. Therefore, cracks and fractures play a significant role in extraction of geothermal energy by providing the major pathways for fluid flow and heat exchange. Thus, knowledge of conditions leading to formation of fractures and fracture networks is of paramount importance. Furthermore, in the absence of natural fractures or adequate connectivity, artificial fracture are created in the reservoir using hydraulic fracturing. At times, the practice aims to create a number of parallel fractures connecting a pair of wells. Multiple fractures are preferred because of the large size necessary when using only a single fracture. Although the basic idea is rather simple, hydraulic fracturing is a complex process involving interactions of high pressure fluid injections with a stressed hot rock mass, mechanical interaction of induced fractures with existing natural fractures, and the spatial and temporal variations of in-situ stress. As a result it is necessary to develop tools that can be used to study these interactions as an integral part of a comprehensive approach to geothermal reservoir development, particularly enhanced geothermal systems. In response to this need we have set out to develop advanced thermo-mechanical models for design of artificial fractures and rock fracture research in geothermal reservoirs. These models consider the significant hydraulic and thermo-mechanical processes and their interaction with the in-situ stress state. Wellbore failure and fracture initiation is studied using a model that fully couples poro-mechanical and thermo-mechanical effects. The fracture propagation model is based on a complex variable and regular displacement discontinuity formulations. In the complex variable approach the displacement discontinuities are

  7. Lead Poisoning

    Science.gov (United States)

    ... lead is of microscopic size, invisible to the naked eye. More often than not, children with elevated ... majority of the childhood lead poisoning cases we see today. Children and adults too can get seriously ...

  8. Relational Leading

    DEFF Research Database (Denmark)

    2015-01-01

    This first chapter presents the exploratory and curious approach to leading as relational processes – an approach that pervades the entire book. We explore leading from a perspective that emphasises the unpredictable challenges and triviality of everyday life, which we consider an interesting......, relevant and realistic way to examine leading. The chapter brings up a number of concepts and contexts as formulated by researchers within the field, and in this way seeks to construct a first understanding of relational leading....

  9. Constraint corrected fracture mechanics in structural integrity assessment

    Energy Technology Data Exchange (ETDEWEB)

    Laukkanen, A.; Wallin, K. [VTT Industrial Systems, Espoo (Finland)

    2004-07-01

    Specimen size, crack depth and loading conditions may affect the materials fracture toughness. In order to safeguard against these geometry effects, fracture toughness testing standards prescribe the use of highly constrained deep cracked bend specimens having a sufficient size to guarantee conservative fracture toughness values. One of the more advanced testing standards, for brittle fracture, is the Master Curve standard ASTM E1921, which is based on technology developed at VTT Industrial Systems. When applied to a structure with low constraint geometry, the standard fracture toughness estimates may lead to strongly over-conservative estimate of structural performance. In some cases this may lead to unnecessary repairs or even to an early 'retirement' of the structure. In the case of brittle fracture, essentially three different methods to quantify constraint have been proposed, J-small scale yielding correction (SSYC), Q-parameter and the T{sub stress}. (orig.)

  10. Proximal humerus fractures.

    Science.gov (United States)

    Price, Matthew C; Horn, Pamela L; Latshaw, James C

    2013-01-01

    Proximal humerus fractures are among the most common fractures associated with osteoporosis. With an aging population, incidence of these fractures will only increase. The proximal humerus not only forms the lateral portion of the shoulder articulation but also has significant associations with musculoskeletal and neurovascular structures. As a result, fractures of the proximal humerus can significantly impact not only the function of the shoulder joint, but the health and function of the entire upper extremity as well. Understanding of these fractures, the management options, and associated nursing care, can help reduce morbidity rate and improve functional outcomes.

  11. Stress fractures in runners.

    Science.gov (United States)

    McCormick, Frank; Nwachukwu, Benedict U; Provencher, Matthew T

    2012-04-01

    Stress fractures are a relatively common entity in athletes, in particular, runners. Physicians and health care providers should maintain a high index of suspicion for stress fractures in runners presenting with insidious onset of focal bone tenderness associated with recent changes in training intensity or regimen. It is particularly important to recognize “high-risk” fractures, as these are associated with an increased risk of complication. A patient with confirmed radiographic evidence of a high-risk stress fracture should be evaluated by an orthopedic surgeon. Runners may benefit from orthotics, cushioned sneakers, interval training, and vitamin/calcium supplementation as a means of stress fracture prevention.

  12. Role of MRI in hip fractures, including stress fractures, occult fractures, avulsion fractures

    Energy Technology Data Exchange (ETDEWEB)

    Nachtrab, O. [Department of Radiology, The Robert Jones and Agnes Hunt Orthopaedic Hospital, Gobowen, Oswestry Shropshire SY10 7AG (United Kingdom); Cassar-Pullicino, V.N., E-mail: Victor.Pullicino@rjah.nhs.uk [Department of Radiology, The Robert Jones and Agnes Hunt Orthopaedic Hospital, Gobowen, Oswestry Shropshire SY10 7AG (United Kingdom); Lalam, R.; Tins, B.; Tyrrell, P.N.M.; Singh, J. [Department of Radiology, The Robert Jones and Agnes Hunt Orthopaedic Hospital, Gobowen, Oswestry Shropshire SY10 7AG (United Kingdom)

    2012-12-15

    MR imaging plays a vital role in the diagnosis and management of hip fractures in all age groups, in a large spectrum of patient groups spanning the elderly and sporting population. It allows a confident exclusion of fracture, differentiation of bony from soft tissue injury and an early confident detection of fractures. There is a spectrum of MR findings which in part is dictated by the type and cause of the fracture which the radiologist needs to be familiar with. Judicious but prompt utilisation of MR in patients with suspected hip fractures has a positive therapeutic impact with healthcare cost benefits as well as social care benefits.

  13. Fractures in multiple sclerosis

    DEFF Research Database (Denmark)

    Stenager, E; Jensen, K

    1991-01-01

    In a cross-sectional study of 299 MS patients 22 have had fractures and of these 17 after onset of MS. The fractures most frequently involved the femoral neck and trochanter (41%). Three patients had had more than one fracture. Only 1 patient had osteoporosis. The percentage of fractures increased...... with increasing age and disease duration. Among 34 deceased MS patients 4 had had fractures. These findings are discussed in relation to physical and cognitive impairment in MS. A case-control study is recommended....

  14. Fracture of the neck of the femur after radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Gantscheff, M.; Wassilew, T.; Tantschew, P. (Meditsinska Akademiya, Sofia (Bulgaria))

    1983-02-01

    Several etiopathogenetic factors of the femoral neck fracture after radiotherapy are discussed taking extensive references into consideration. Results are described paying special attention to the discongruence of the hip joint existing in this fracture. The change of the volume of the femoral head, which can be considered as a consecutive symptom of some vascular lesions, leads to pathologic conditions in the biomechanics of the hip joint causing a special kind of stress fracture.

  15. [Fractures of carpal bones].

    Science.gov (United States)

    Lögters, T; Windolf, J

    2016-10-01

    Fractures of the carpal bones are uncommon. On standard radiographs fractures are often not recognized and a computed tomography (CT) scan is the diagnostic method of choice. The aim of treatment is to restore pain-free and full functioning of the hand. A distinction is made between stable and unstable carpal fractures. Stable non-displaced fractures can be treated conservatively. Unstable and displaced fractures have an increased risk of arthritis and non-union and should be stabilized by screws or k‑wires. If treated adequately, fractures of the carpal bones have a good prognosis. Unstable and dislocated fractures have an increased risk for non-union. The subsequent development of carpal collapse with arthrosis is a severe consequence of non-union, which has a heterogeneous prognosis.

  16. Orbital fractures: a review

    Directory of Open Access Journals (Sweden)

    Jeffrey M Joseph

    2011-01-01

    Full Text Available Jeffrey M Joseph, Ioannis P GlavasDivision of Ophthalmic Plastic and Reconstructive Surgery, Department of Ophthalmology, School of Medicine, New York University, New York, NY, USA; Manhattan Eye, Ear, and Throat Hospital, New York, NY, USAAbstract: This review of orbital fractures has three goals: 1 to understand the clinically relevant orbital anatomy with regard to periorbital trauma and orbital fractures, 2 to explain how to assess and examine a patient after periorbital trauma, and 3 to understand the medical and surgical management of orbital fractures. The article aims to summarize the evaluation and management of commonly encountered orbital fractures from the ophthalmologic perspective and to provide an overview for all practicing ophthalmologists and ophthalmologists in training.Keywords: orbit, trauma, fracture, orbital floor, medial wall, zygomatic, zygomatic complex, zmc fracture, zygomaticomaxillary complex fractures 

  17. Oblique Axis Body Fracture

    DEFF Research Database (Denmark)

    Takai, Hirokazu; Konstantinidis, Lukas; Schmal, Hagen

    2016-01-01

    Purpose. Anderson type III odontoid fractures have traditionally been considered stable and treated conservatively. However, unstable cases with unfavorable results following conservative treatment have been reported. Methods. We present the cases of two patients who sustained minimally displaced...... Anderson type III fractures with a characteristic fracture pattern that we refer to as "oblique type axis body fracture." Results. The female patients aged 90 and 72 years, respectively, were both diagnosed with minimally displaced Anderson type III fractures. Both fractures had a characteristic "oblique...... type" fracture pattern. The first patient was treated conservatively with cervical spine immobilization in a semirigid collar. However, gross displacement was noted at the 6-week follow-up visit. The second patient was therefore treated operatively by C1-C3/4 posterior fusion and the course...

  18. Two-Dimensional Heat Transfer in a Heterogeneous Fracture Network

    Science.gov (United States)

    Gisladottir, V. R.; Roubinet, D.; Tartakovsky, D. M.

    2015-12-01

    Geothermal energy harvesting requires extraction and injection of geothermal fluid. Doing so in an optimal way requires a quantitative understanding of site-specific heat transfer between geothermal fluid and the ambient rock. We develop a heat transfer particle-tracking approach to model that interaction. Fracture-network models of heat transfer in fractured rock explicitly account for the presence of individual fractures, ambient rock matrix, and fracture-matrix interfaces. Computational domains of such models span the meter scale, whereas fracture apertures are on the millimeter scale. The computations needed to model these multi-scale phenomenon can be prohibitively expensive, even for methods using nonuniform meshes. Our approach appreciably decreases the computational costs. Current particle-tracking methods usually assume both infinite matrix and one-dimensional (1D) heat transfer in the matrix blocks. They rely on 1D analytical solutions for heat transfer in a single fracture, which can lead to large predictive errors. Our two-dimensional (2D) heat transfer simulation algorithm is mesh-free and takes into account both longitudinal and transversal heat conduction in the matrix. It uses a probabilistic model to transfer particle to the appropriate neighboring fracture unless it returns to the fracture of origin or remains in the matrix. We use this approach to look at the impact of a fracture-network topology (e.g. the importance of smaller scale fractures), as well as the matrix block distribution on the heat transport in heterogeneous fractured rocks.

  19. [Fracture endoprosthesis of distal humerus fractures].

    Science.gov (United States)

    Müller, L P; Wegmann, K; Burkhart, K J

    2013-08-01

    The treatment of choice for fractures of the distal humerus is double plate osteosynthesis. Due to anatomical preshaped angle stable plates the primary stability and management of soft tissues has been improved. However, osteoporotic comminuted fractures in the elderly are often not amenable to stable osteosynthesis and total elbow arthroplasty has been established as an alternative therapy. Although complication rates have been reduced, complications of total elbow arthroplasty are still much more frequent than in total hip replacement. Furthermore, patients are advised not to exceed a weight bearing of 5 kg. Therefore, the indications for elbow arthroplasty must be evaluated very strictly and should be reserved for comminuted distal humeral fractures in the elderly with poor bone quality that are not amenable to stable osteosynthesis or for simple fractures in cases of preexisting symptomatic osteoarthritis. This article introduces and discusses modern concepts of elbow arthroplasty, such as modular convertible prosthesis systems, hemiarthroplasty and radial head replacement in total elbow arthroplasty.

  20. Lead Test

    Science.gov (United States)

    ... months, and at 3, 4, 5, and 6 years of age. A blood lead level test should be done only if the risk ... recommended if the person is symptomatic at any level below 70 mcg/dL. Because lead will pass through the blood to an unborn child, pregnant ...

  1. Dislocated ankle fracture complicated by near total distal ischaemia

    Science.gov (United States)

    Duygun, Fatih; Sertkaya, Omer; Aldemir, Cengiz; Dogan, Ali

    2013-01-01

    Total arterial ischaemia is rarely seen following a dislocated ankle fracture but if it does and intervention is not made, it can lead to serious morbidity. We present a 39-year-old woman with almost total occlusion in the arteria tibialis and arteria dorsalis pedis following a dislocated ankle fracture as a result of a bicycle fall. PMID:24248319

  2. Jaw fractures in children.

    Science.gov (United States)

    Kotilainen, R; Kärjä, J; Kullaa-Mikkonen, A

    1990-03-01

    From a total of 350 jaw fractures treated in 1980-1984 at Kuopio University Central Hospital, 20% were in children. These injuries were evaluated retrospectively regarding age, sex, incidence and etiology. Forty-five of the patients were boys and 25 girls. The frequency of maxillary and mandibular fractures in 70 young patients was 28.6%. The most common type of bone fractures was fracture of the alveolar process, which was prevalent in persons with mixed dentition. Before the age of 7 years, falls from height were the common causes of jaw fractures. The major cause of the jaw fractures in children from 7 to 15 years old was road accidents (47.1%), especially in boys. Most of these were cycling accidents, only a few patients were victims of automobile accidents. In addition, about one third (25.7%) of the patients were treated in the hospital because of multiple injuries to other organs.

  3. Adult Monteggia and Olecranon Fracture Dislocations of the Elbow.

    Science.gov (United States)

    Wong, Justin C; Getz, Charles L; Abboud, Joseph A

    2015-11-01

    Monteggia fractures and olecranon fracture dislocations represent complex injuries with distinct patterns of bony and soft tissue involvement. Fractures of the proximal ulna and olecranon process may lead to disruption of the proximal radioulnar joint and/or ulnohumeral joint. The keys to treatment are recognition of the pattern of injury and formation of an algorithmic surgical plan to address all components of the injury process. Complications are common and may be related to the injury spectrum itself and/or inadequate fracture alignment or fixation.

  4. Pelvic fractures and mortality.

    OpenAIRE

    K.H. Chong; DeCoster, T.; Osler, T.; Robinson, B.

    1997-01-01

    A retrospective study of all patients (N = 343) with pelvic fractures admitted to our trauma service was conducted to evaluate the impact of pelvic fractures on mortality. All patients sustained additional injuries with an average Injury Severity Score (ISS) of twenty. Thirty-six patients died. This group had more severe pelvic fractures as graded by the Tile classification as well as a greater number and severity of associated injuries. Six patients died as a direct result of pelvic hemorrha...

  5. Oblique Axis Body Fracture

    DEFF Research Database (Denmark)

    Takai, Hirokazu; Konstantinidis, Lukas; Schmal, Hagen;

    2016-01-01

    was uneventful. Conclusions. Oblique type axis body fractures resemble a highly unstable subtype of Anderson type III fractures with the potential of severe secondary deformity following conservative treatment, irrespective of initial grade of displacement. The authors therefore warrant a high index of suspicion......Purpose. Anderson type III odontoid fractures have traditionally been considered stable and treated conservatively. However, unstable cases with unfavorable results following conservative treatment have been reported. Methods. We present the cases of two patients who sustained minimally displaced...

  6. [(Impending) pathological fracture].

    Science.gov (United States)

    Sutter, P M; Regazzoni, P

    2002-01-01

    Pathological fractures will be encountered in increasing frequency due to more patients with cancer, surviving a longer period. The skeleton is the third most frequent localization for metastases. Breast cancer is still the most common primary tumor, but bone metastases from lung cancer seem to be diagnosed more and more. Despite of finding metastases most often in the spinal column, fractures are seen mostly at the femoral site. A pathological fracture and, in almost all cases, an impending fracture are absolute indication for operation. An exact definition of an "impending fracture" is still lacking; it is widely accepted, that 50 per cent of bone mass must be destroyed before visualization in X-ray is possible, thus defining an impending fracture. The score system by Mirels estimates the fracture risk by means of four parameters (localization, per cent of destructed bone mass, type of metastasis, pain). Improving quality of life, relieving pain, preferably with a single operation and a short length of stay are the goals of (operative) treatment. For fractures of the proximal femur, prosthetic replacement, for fractures of the subtrochanteric region or the shaft, intramedullary nails are recommended. Postoperative radiation therapy possibly avoids tumor progression. In patient with a good long term prognosis, tumor should be removed locally aggressive.

  7. Fracture mechanics safety approaches

    Energy Technology Data Exchange (ETDEWEB)

    Roos, E.; Schuler, X.; Eisele, U. [Materials Testing Inst. (MPA), Univ. of Stuttgart (Germany)

    2004-07-01

    Component integrity assessments require the knowledge of reliable fracture toughness parameters characterising the initiation of the failure process in the whole relevant temperature range. From a large number of fracture mechanics tests a statistically based procedure was derived allowing to quantify the initiation of fracture toughness as a function of temperature as a closed function as well as the temperature dependence of the cleavage instability parameters. Alternatively to the direct experimental determination one also can use a correlation between fracture toughness and notch impact energy. (orig.)

  8. Scaphoid fractures in children

    Directory of Open Access Journals (Sweden)

    Gajdobranski Đorđe

    2014-01-01

    Full Text Available Introduction. Scaphoid fractures are rare in childhood. Diagnosis is very difficult to establish because carpal bones are not fully ossified. In suspected cases comparative or delayed radiography is used, as well as computerized tomography, magnetic resonance imaging, ultrasound and bone scintigraphy. Majority of scaphoid fractures are treated conservatively with good results. In case of delayed fracture healing various types of treatment are available. Objective. To determine the mechanism of injury, clinical healing process, types and outcome of treatment of scaphoid fractures in children. Methods. We retrospectively analyzed patients with traumatic closed fracture of the scaphoid bone over a ten-year period (2002-2011. The outcome of the treatment of “acute” scaphoid fracture was evaluated using the Mayo Wrist Score. Results. There were in total 34 patients, of mean age 13.8 years, with traumatic closed fracture of the scaphoid bone, whose bone growth was not finished yet. Most common injury mechanism was fall on outstretched arm - 76% of patients. During the examined period 31 children with “acute” fracture underwent conservative treatment, with average immobilization period of 51 days. Six patients were lost to follow-up. In the remaining 25 patients, after completed rehabilitation, functional results determined by the Mayo Wrist Score were excellent. Conclusion. Conservative therapy of “acute” scaphoid fractures is an acceptable treatment option for pediatric patients with excellent functional results.

  9. Atraumatic First Rib Fracture

    Directory of Open Access Journals (Sweden)

    Koray Aydogdu

    2014-12-01

    Full Text Available Rib fractures are usually seen after a trauma, while atraumatic spontaneous rib fractures are quite rare. A first rib fracture identified in our 17 years old female patient who had not a history of trauma except lifting a heavy weight was examined in details in terms of the potential complications and followed-up for a long time. We presented our experience on this case with atraumatic first rib fracture that has different views for the etiology in light of the literature.

  10. Lead Poisoning

    Science.gov (United States)

    ... Topics Environment & Health Healthy Living Pollution Reduce, Reuse, Recycle Science – How It Works The Natural World Games ... OTHERS: Lead has recently been found in some plastic mini-blinds and vertical blinds which were made ...

  11. Magnetic anomalies over fracture zones in the central North Atlantic Ocean

    NARCIS (Netherlands)

    Twigt, W.

    1980-01-01

    The offset of a fracture zone leads to a configuration in which a strip of oceanic crust of one age will be juxtaposed axially to a strip of another age. Consequently, the polarity of the magnetic layer may be different on either side of the fracture zone. Next to this magnetic contrast the fracture

  12. Magnetic anomalies over fracture zones in the central North Atlantic Ocean

    NARCIS (Netherlands)

    Twigt, W

    1980-01-01

    The offset of a fracture zone leads to a configuration in which a strip of oceanic crust of one age will be juxtaposed axially to a strip of another age. Consequently, the polarity of the magnetic layer may be different on either side of the fracture zone. Next to this magnetic contrast the fracture

  13. STUDY OF FUNCTIONAL OUTCOME OF SURGICAL MANAGEMENT OF UNSTABLE MALLEOLAR FRACTURES IN ADULTS : A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Sankara Rao

    2015-09-01

    Full Text Available Malleolar fractures are one of the most common lower extremity fractures in orthopaedic traumatology. Ankle injuries gain importance because body weight is transmitted through it and locomotion depends upon the stability of this joint. Malleolar fractures have varied presentations which have given rise to a wide variety of classification systems, of which two ar e in vogue Lauge - Hansens and Danis - Weber classification. As with all intra articular fractures, malleolar fractures necessitate accurate reduction and stable internal fixation. When malleolar fractures are not reduced accurately they may lead to post tra umatic painful restriction of motion or osteoarthritis or both .

  14. Lower limb fractures associated with multiligament knee injury

    Science.gov (United States)

    Stagnaro, Joaquin; Yacuzzi, Carlos; Barla, Jorge; Zicaro, Juan Pablo; Costa-Paz, Matias

    2017-01-01

    Objectives: Knee ligament injuries related to lower limb fractures are common and frequently unnoticed. Management of acute polytrauma is usually focused in the bone lesion and a complete physical examination might be really difficult. The purpose of this study was to analyze a series of patients who suffered multiligament knee injuries associated to a lower limb fracture. Hypothesis: The use of magnetic resonance imaging (MRI) during the initial management can lead to an early diagnosis of ligament injuries. Methods: A retrospective search was conducted from our hospital´s electronic database. We evaluated the initial diagnosis and acute surgical treatment, and management and functional outcomes after the ligament lesion was diagnosed. Results: Seven patients who presented a knee multiligament injury associated with a lower limb fracture were evaluated. The average age was 29 years. Primary diagnoses were: four tibial plateau fractures; one open fracture-dislocation of the knee; one open leg fracture and ipsilateral hip dislocation; and one bifocal femur fracture. Only three patients had an MRI during the initial management of trauma. Six out of seven patients had to be operated on for the multiligament knee injury. The period between the resolution of the fracture and the ligamentous repair was from 3 to 24 months. Conclusion: Poor functional outcomes are reported in patients with multiligament knee injuries associated with high-energy lower limb fractures. We consider an MRI during the initial management can lead to better outcomes. A trauma surgeon working alongside an arthroscopic surgeon might optimize the results for these lesions.

  15. The epidemiology of osteoporosis and fractures in ankylosing spondylitis.

    Science.gov (United States)

    Sambrook, Philip N; Geusens, Piet

    2012-08-01

    Bone is a target in many inflammatory rheumatic diseases. Inflammation leads to a wide range of changes in bone, and especially bone remodeling. In ankylosing spondylitis (AS) bone loss has been documented, but measuring bone density in the spine is hampered by new bone formation in syndesmophytes, periost and within the vertebrae. The risk of vertebral fractures is increased in AS. The diagnosis of vertebral fractures requires imaging and adequate evaluation of vertebral heights. In addition, in the ankysosed spine segments, additional imaging is often needed to diagnose spinal fractures at unusual locations (cervical spine) or in the posterior arch structures. Risk factors for vertebral fractures are helpful for case finding. Fracture prevention is indicated in high risk patients with AS, especially when they have already a vertebral fracture or in the presence of osteoporosis.

  16. La salute del civis-fidelis nei distinti ordini dello Stato e della Chiesa cattolica. Le aspettative ascetiche della persona nella connotazione del bene salute

    Directory of Open Access Journals (Sweden)

    Tiziana Di Iorio

    2015-06-01

    Full Text Available Contributo sottoposto a valutazione SOMMARIO: 1. Autonomia confessionale e sovranità dello Stato: la distinzione tra ordini “distinti” – 2. Il principio di laicità e la valorizzazione delle differenze, nell’inderogabile esigenza di salvaguardia dei diritti della persona – 3. Tutela della salute: diritto fondamentale della Costituzione italiana – 4. La dimensione ascetica dell’individuo nella concezione giuridica del bene salute – 5. La salute nell’ordinamento canonico: connotazione di un bene con valore relativo – 6. La realizzazione “responsabile” della salute e la sua intrinseca connessione con la salvezza nella Chiesa – 7. La sana cooperatiotra Stato e Chiesa nella tutela della salute del civis-fidelis – 8. Conclusioni. ABSTRACT Health of the civis-fidelis in the different systems of the Italian State and the Catholic Church. The spiritual needs of the individual as included in the meaning of health  The meaning of "health" in a legal system depends upon its culture and social development, so that time and space influence the way protection is offered. Nowadays the idea of “health” has enlarged. In the past the meaning of health was intended as a mental-physical well-being; it has now gradually developed to a larger meaning, including a complete physical, mental and social well-being and not merely the absence of disease. Along with Italian constitution, Italy has to pursue and protect the health of any individual, not just citizens. Health is also protected by the Church as a precious gift given by God to man and is closely linked with salvation. Man is called to protect the value of this gift in its widest configuration. Therefore the integral protection of health requires to take into account all the dimensions of the individual, both as civis and fidelis. In order to reach this target it is necessary an open dialogue between civil authorities and religious institution; its importance relies on the

  17. Advances and disputes of posterior malleolus fracture

    Institute of Scientific and Technical Information of China (English)

    FU Su; ZOU Zhen-yu; MEI Gang; JIN Dan

    2013-01-01

    Objective The objective of this article is to summarize the development of evaluation and treatment of posterior malleolus fracture (PMF).Data sources Data used in this review were mainly from English literature of PubMed data base.Study selection Articles were included in this review if they were related to the PMF or trimalleolar fracture.Results No consensus was found regarding what sizes of posterior malleolus fragments would lead to ankle instability thus affecting prognosis and should be fixed.Ⅹ-ray measurement is unreliable,while CT scan is widely recommended and it can recognize the occult posterior malleolus fractures associated with tibia shaft fractures,which are always undetected previously.Direct posterior malleolus fixation is suitable to stabilize syndesmotic injury.The basic and clinical researches support direct reduction and buttress plate fixation of posterior malleolus fracture through the posterolateral approach.Operative indications and timing of weight bearing are still in discussion.Conclusions Knowing whether ankle instability occurs and the proper methods to diagnose,evaluate,and operate can help manage the fracture.Further biomechanical research on ankle stability and clinical study to compare various treatment methods are required.

  18. Hip Fractures among Older Adults

    Science.gov (United States)

    ... online training for health care providers. Learn More Hip Fractures Among Older Adults Recommend on Facebook Tweet Share ... get older. What You Can Do to Prevent Hip Fractures You can prevent hip fractures by taking steps ...

  19. Pneumothorax complicating isolated clavicle fracture.

    Science.gov (United States)

    Hani, Redouane; Ennaciri, Badr; Jeddi, Idriss; El Bardouni, Ahmed; Mahfoud, Mustapha; Berrada, Mohamed Saleh

    2015-01-01

    Isolated clavicle fractures are among the commonest of traumatic fractures in the emergency department. Complications of isolated clavicle fractures are rare. Pneumothorax has been described as a complication of a fractured clavicle only rarely in English literature. In all the reported cases, the pneumothorax was treated by a thoracostomy and the clavicle fracture was treated conservatively. In our case, the pneumothorax required a chest drain insertion and the clavicle fracture was treated surgically with good result.

  20. Atypical Subtrochanteric Femur Fracture in Patient with Metastatic Breast Cancer Treated with Zoledronic Acid

    OpenAIRE

    2012-01-01

    Several case series have suggested an association exists between atypical femoral subtrochanteric fractures and long-term use of bisphosphonates. It is thought that prolonged use of bisphosphonates may lead to adynamic, fragile bone. The radiologic features of atypical fractures include diffuse cortical thickening, transverse fracture, and beaking at the lateral subtrochanteric area. Atypical subtrochanteric femur fractures have been reported after use of alendronate, but there have been rare...

  1. Vertebral Fracture Prediction

    DEFF Research Database (Denmark)

    2008-01-01

    Vertebral Fracture Prediction A method of processing data derived from an image of at least part of a spine is provided for estimating the risk of a future fracture in vertebraeof the spine. Position data relating to at least four neighbouring vertebrae of the spine is processed. The curvature...

  2. Radial head fracture - aftercare

    Science.gov (United States)

    ... Philadelphia, PA: Elsevier Saunders; 2015:chap 6. Prawer A. Radius and ulna fractures. In: Eiff M, Hatch R, eds. Fracture Management for Primary Care . 3rd ed. Philadelphia, PA: Elsevier Saunders; 2012:chap ... PhD, and the A.D.A.M. Editorial team. Related MedlinePlus Health ...

  3. Displaced patella fractures.

    Science.gov (United States)

    Della Rocca, Gregory J

    2013-10-01

    Displaced patella fractures often result in disruption of the extensor mechanism of the knee. An intact extensor mechanism is a requirement for unassisted gait. Therefore, operative treatment of the displaced patella fracture is generally recommended. The evaluation of the patella fracture patient includes examination of extensor mechanism integrity. Operative management of patella fractures normally includes open reduction with internal fixation, although partial patellectomy is occasionally performed, with advancement of quadriceps tendon or patellar ligament to the fracture bed. Open reduction with internal fixation has historically been performed utilizing anterior tension band wiring, although comminution of the fracture occasionally makes this fixation construct inadequate. Supplementation or replacement of the tension band wire construct with interfragmentary screws, cerclage wire or suture, and/or plate-and-screw constructs may add to the stability of the fixation construct. Arthrosis of the patellofemoral joint is very common after healing of patella fractures, and substantial functional deficits may persist long after fracture healing has occurred. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  4. THORACIC SPINE FRACTURES

    Institute of Scientific and Technical Information of China (English)

    戴力扬

    2001-01-01

    Objective. To investigate the unique characteristics and treatment of thoracic spine fractures.Methods. Severty-seven patients with thoracic spine fractures were retrospectively reviewed. Of these, therewere 37 compressior fractures, 34 fracture-dislocations, 3 burst fractures and 3 burst-dislocations. Twenty-six pa-tients had a complete lesion of the spinal cord, 14 sustained a neurologically incomplete injury, and 37 wereneurologically intact. Fifty-three patients were treated nonoperatively and 24 treated operatively.Results. All patients were followed up for 2 ~ 15 years. None of the 26 patients with a complete lesion recov-ered any significant function. Of 37 neurologically intact patients, 13 had local pain although all of them re-mained normal function. Two of 14 patients with incomplete paraplegia returned to normal, 7 recovered some func-tion and 5 did not recovered.Conclusions. E ecause of the unique anatomy and biomechanics of the thoracic spine, the classification common-ly applied to thoracolumbar fractures is not suitable for thoracic fractures. Fusion and instrumentation are indicat-ed when the fractures are unstable, while patients with incomplete lesion of the spinal cord may be the candidatesfor supplemented decompression.

  5. Ecotoxicology: Lead

    Science.gov (United States)

    Scheuhammer, A.M.; Beyer, W.N.; Schmitt, C.J.; Jorgensen, Sven Erik; Fath, Brian D.

    2008-01-01

    Lead (Pb) is a naturally occurring metallic element; trace concentrations are found in all environmental media and in all living things. However, certain human activities, especially base metal mining and smelting; combustion of leaded gasoline; the use of Pb in hunting, target shooting, and recreational angling; the use of Pb-based paints; and the uncontrolled disposal of Pb-containing products such as old vehicle batteries and electronic devices have resulted in increased environmental levels of Pb, and have created risks for Pb exposure and toxicity in invertebrates, fish, and wildlife in some ecosystems.

  6. Conservation of major and minor jelly-roll capsid proteins in Polinton (Maverick) transposons suggests that they are bona fide viruses.

    Science.gov (United States)

    Krupovic, Mart; Bamford, Dennis H; Koonin, Eugene V

    2014-04-29

    Polintons (also known as Mavericks) and Tlr elements of Tetrahymena thermophila represent two families of large DNA transposons widespread in eukaryotes. Here, we show that both Polintons and Tlr elements encode two key virion proteins, the major capsid protein with the double jelly-roll fold and the minor capsid protein, known as the penton, with the single jelly-roll topology. This observation along with the previously noted conservation of the genes for viral genome packaging ATPase and adenovirus-like protease strongly suggests that Polintons and Tlr elements combine features of bona fide viruses and transposons. We propose the name 'Polintoviruses' to denote these putative viruses that could have played a central role in the evolution of several groups of DNA viruses of eukaryotes.

  7. MRI Could Be Changed Vertebral Body Fracture Classification

    Directory of Open Access Journals (Sweden)

    J. Jalal Shokouki

    2008-01-01

    Full Text Available Background/Objective: Evaluation of spinal column fracture or trauma with MRI in more than two years among 500 patients can change classifications of frac-tures that is important because of intervention ther-apy methods like vertebroplasty and kyfoplasty. As there are changes at Salter harrie fractures, classifica-tion, treatments` way, and management of vertebral body fracture will change. Also MRI can show inter-nal parts ruptures, vessel punctures, and show the size of hematomas."nPatients and Methods: Fifty patients at two imaging centers have been tested with MRI 1.5 tesla machines from GE and Siemens with superficial coil, and all of them had vertebral column trauma. We used T1 and T2 sagital and in some cases STIR or FAT SAT sagital. "nResults: Among our cases, 147 had fractures, and two cases had spinal punctures. The most common from of fractures were anterior wedging with compression of upper endplate. "nThe maximum fractures were five in a single trauma and mostly there were 2-3 fractures in a single trau-ma. Most of the fractures did not appear at X-ray, but they revealed at MRI specially with STIR pulse."nConclusion: 1 MRI especially STIR pulse is definite and sensitive to compression even in slight among which can be hidden from X-ray and CT. 2 Findings number and form of fractures with MRI, comparing with clinical signs will change classification of verte-bral fractures that leads to the better treatment re-sults. 3 CT is better for vertebral appendix fractures. 4 MRI is better for seeing complications of soft tis-sue. 5 MRI is better for siagnosins of old complica-tions and old fractures.

  8. Transphyseal Distal Humerus Fracture.

    Science.gov (United States)

    Abzug, Joshua; Ho, Christine Ann; Ritzman, Todd F; Brighton, Brian

    2016-01-01

    Transphyseal distal humerus fractures typically occur in children younger than 3 years secondary to birth trauma, nonaccidental trauma, or a fall from a small height. Prompt and accurate diagnosis of a transphyseal distal humerus fracture is crucial for a successful outcome. Recognizing that the forearm is not aligned with the humerus on plain radiographs may aid in the diagnosis of a transphyseal distal humerus fracture. Surgical management is most commonly performed with the aid of an arthrogram. Closed reduction and percutaneous pinning techniques similar to those used for supracondylar humerus fractures are employed. Cubitus varus caused by a malunion, osteonecrosis of the medial condyle, or growth arrest is the most common complication encountered in the treatment of transphyseal distal humerus fractures. A corrective lateral closing wedge osteotomy can be performed to restore a nearly normal carrying angle.

  9. Galeazzi fracture-dislocations.

    Science.gov (United States)

    Mikić, Z D

    1975-12-01

    Among 125 patients with the Galeazzi-type fracture-dislocation of the forearm, there were fourteen children and eighty-six adults with the classic Galeazzi lesion, and twenty-five patients with a special type -- fracture of both bones and dislocation of the distal radio-ulnar joint. Conservative management was successful only in children. In adults this method resulted in failure in 80 per cent of cases. The results of operative treatment were much better. The fracture fragments of the radius and the dislocation of the radio-ulnar joint in this complex injury are very unstable, especially in the lesion with fractures of the radius and ulna, and it appears that rigid internal fixation is necessary for the dislocation as well as the fracture. With combined fixation over half of the results were excellent.

  10. Dynamic fracture mechanics

    Science.gov (United States)

    Kobayashi, A. S.; Ramulu, M.

    1985-01-01

    Dynamic fracture and crack propagation concepts for ductile materials are reviewed. The equations for calculating dynamic stress integrity and the dynamic energy release rate in order to study dynamic crack propagation are provided. The stress intensity factor versus crack velocity relation is investigated. The uses of optical experimental techniques and finite element methods for fracture analyses are described. The fracture criteria for a rapidly propagating crack under mixed mode conditions are discussed; crack extension and fracture criteria under combined tension and shear loading are based on maximum circumferential stress or energy criteria such as strain energy density. The development and use of a Dugdale model and finite element models to represent crack and fracture dynamics are examined.

  11. Tibial Plateau Fractures

    DEFF Research Database (Denmark)

    Elsøe, Rasmus

    This PhD thesis reported an incidence of tibial plateau fractures of 10.3/100,000/year in a complete Danish regional population. The results reported that patients treated for a lateral tibial plateau fracture with bone tamp reduction and percutaneous screw fixation achieved a satisfactory level...... with only the subgroup Sport significantly below the age matched reference population. The thesis reports a level of health related quality of life (Eq5d) and disability (KOOS) significantly below established reference populations for patients with bicondylar tibial plateau fracture treated with a ring...... fixator, both during treatment and at 19 months following injury. In general, the thesis demonstrates that the treatment of tibial plateau fractures are challenging and that some disabilities following these fractures must be expected. Moreover, the need for further research in the area, both with regard...

  12. Dating fractures in infants

    Energy Technology Data Exchange (ETDEWEB)

    Halliday, K.E., E-mail: kath.halliday@nuh.nhs.uk [Department of Radiology, Nottingham University Hospitals, Queen' s Medical Centre, Nottingham (United Kingdom); Broderick, N.J.; Somers, J.M. [Department of Radiology, Nottingham University Hospitals, Queen' s Medical Centre, Nottingham (United Kingdom); Hawkes, R. [Department of Radiology, Paul O' Gorman Building, Bristol (United Kingdom)

    2011-11-15

    Aim: To document the timing of the appearance of the radiological features of fracture healing in a group of infants in which the date of injury was known and to assess the degree of interobserver agreement. Materials and methods: Three paediatric radiologists independently assessed 161 images of 37 long bone fractures in 31 patients aged 0-44 months. The following features were assessed: soft-tissue swelling, subperiosteal new bone formation (SPNBF), definition of fracture line, presence or absence of callus, whether callus was well or ill defined, and the presence of endosteal callus. Results: Agreement between observers was only moderate for all discriminators except SPNBF. SPNBF was invariably seen after 11 days but was uncommon before this time even in the very young. In one case SPNBF was seen at 4 days. Conclusion: With the exception of SPNBF, the criteria relied on to date fractures are either not reproducible or are poor discriminators of fracture age.

  13. Leading men

    DEFF Research Database (Denmark)

    Bekker-Nielsen, Tønnes

    2016-01-01

    Through a systematic comparison of c. 50 careers leading to the koinarchate or high priesthood of Asia, Bithynia, Galatia, Lycia, Macedonia and coastal Pontus, as described in funeral or honorary inscriptions of individual koinarchs, it is possible to identify common denominators but also...

  14. Lead grids

    CERN Multimedia

    1974-01-01

    One of the 150 lead grids used in the multiwire proportional chamber g-ray detector. The 0.75 mm diameter holes are spaced 1 mm centre to centre. The grids were made by chemical cutting techniques in the Godet Workshop of the SB Physics.

  15. Discrimination-pregnancy leave-Pregnancy Discrimination Act not retroactive-bona fide seniority system. AT&T Corp. v. Hulteen, 2009 U.S. LEXIS 3470 (U.S. 5/18/2009).

    Science.gov (United States)

    2009-01-01

    A pension plan whose terms are those of a bona fide seniority system and which treats pregnancy leave, taken before the addition of the Pregnancy Discrimination Act (PDA) to Title VII, differently than other kinds of medical leave, does not amount to sex and pregnancy discrimination under Title VII because PDA does not apply retroactively.

  16. Computed tomograms of blowout fracture

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Haruhide; Hayashi, Minoru; Shoin, Katsuo; Hwang, Wen-Zern; Yamamoto, Shinjiro; Yonemura, Taizo

    1985-02-01

    We studied 18 cases of orbital fractures, excluding optic canal fracture. There were 11 cases of pure blowout fracture and 3 of the impure type. The other 4 cases were orbital fractures without blowout fracture. The cardinal syndromes were diplopia, enophthalmos, and sensory disturbances of the trigeminal nerve in the pure type of blowout fracture. Many cases of the impure type of blowout fracture or of orbital fracture showed black eyes or a swelling of the eyelids which masked enophthalmos. Axial and coronal CT scans demonstrated: 1) the orbital fracture, 2) the degree of enophthalmos, 3) intraorbital soft tissue, such as incarcerated or prolapsed ocular muscles, 4) intraorbital hemorrhage, 5) the anatomical relation of the orbital fracture to the lacrimal canal, the trochlea, and the trigeminal nerve, and 6) the lesions of the paranasal sinus and the intracranial cavity. CT scans play an important role in determining what surgical procedures might best be employed. Pure blowout fractures were classified by CT scans into these four types: 1) incarcerating linear fracture, 2) trapdoor fracture, 3) punched-out fracture, and 4) broad fracture. Cases with severe head injury should be examined to see whether or not blowout fracture is present. If the patients are to hope to return to society, a blowout fracture should be treated as soon as possible. (author).

  17. Stress fractures: definition, diagnosis and treatment☆

    Science.gov (United States)

    Astur, Diego Costa; Zanatta, Fernando; Arliani, Gustavo Gonçalves; Moraes, Eduardo Ramalho; Pochini, Alberto de Castro; Ejnisman, Benno

    2015-01-01

    Stress fractures were first described in Prussian soldiers by Breithaupt in 1855. They occur as the result of repeatedly making the same movement in a specific region, which can lead to fatigue and imbalance between osteoblast and osteoclast activity, thus favoring bone breakage. In addition, when a particular region of the body is used in the wrong way, a stress fracture can occur even without the occurrence of an excessive number of functional cycles. The objective of this study was to review the most relevant literature of recent years in order to add key information regarding this pathological condition, as an updating article on this topic. PMID:26962487

  18. Spontaneous rib fractures.

    Science.gov (United States)

    Katrancioglu, Ozgur; Akkas, Yucel; Arslan, Sulhattin; Sahin, Ekber

    2015-07-01

    Other than trauma, rib fracture can occur spontaneously due to a severe cough or sneeze. In this study, patients with spontaneous rib fractures were analyzed according to age, sex, underlying pathology, treatment, and complications. Twelve patients who presented between February 2009 and February 2011 with spontaneous rib fracture were reviewed retrospectively. The patients' data were evaluated according to anamnesis, physical examination, and chest radiographs. The ages of the patients ranged from 34 to 77 years (mean 55.91 ± 12.20 years), and 7 (58.4%) were male. All patients had severe cough and chest pain. The fractures were most frequently between 4th and 9th ribs; multiple rib fractures were detected in 5 (41.7%) patients. Eight (66.7%) patients had chronic obstructive pulmonary disease, 2 (16.7%) had bronchial asthma, and 2 (16.7%) had osteoporosis. Bone densitometry revealed a high risk of bone fracture in all patients. Patients with chronic obstructive pulmonary disease or bronchial asthma had been treated with high-dose steroids for over a year. Spontaneous rib fracture due to severe cough may occur in patients with osteoporosis, chronic obstructive pulmonary disease, or bronchial asthma, receiving long-term steroid therapy. If these patients have severe chest pain, chest radiography should be performed to check for bone lesions. © The Author(s) 2015.

  19. Who Leads China's Leading Universities?

    Science.gov (United States)

    Huang, Futao

    2017-01-01

    This study attempts to identify the major characteristics of two different groups of institutional leaders in China's leading universities. The study begins with a review of relevant literature and theory. Then, there is a brief introduction to the selection of party secretaries, deputy secretaries, presidents and vice presidents in leading…

  20. On Estimation of Fracture Aperture with Ground Penetrating Radar

    Science.gov (United States)

    Linde, N.; Shakas, A.

    2016-12-01

    Ground penetrating radar (GPR) is an excellent tool for fracture imaging, but GPR-assisted estimation of fracture aperture is a largely unresolved challenge. The main reason for this is that traditional modeling techniques face severe limitations in fractured rock environments. For example, finite-difference time-domain (FDTD) formulations of Maxwell's equations are poorly adapted to deal with fractures of arbitrary orientations and apertures that are three-five orders of magnitude smaller than the modeling domain. An alternative is to use analytical solutions for thin-bed responses, but they are based on strong assumptions that often do not apply in practise. We have recently developed an efficient modeling approach to simulate GPR propagation and reflection in fractured rock. Here, we first use this modeling formulation to examine the ability of the thin-bed solution to infer the aperture of a homogeneous fracture. We then consider a suite of synthetic examples with heterogeneous fracture aperture fields of varying fractal (Hurst) exponents and spatial correlation lengths. We then use a global optimization algorithm to infer a mean (effective) fracture aperture in each case using the noise-contaminated synthetic data. The thin-bed solution leads to biased aperture estimates even if the fracture has a constant aperture and all other modeling parameters are known. With our modeling approach, we find that appropriate mean apertures are estimated in the homogeneous case, and when the correlation length of the aperture distribution is of similar scale (or larger) than the dominant GPR wavelength.

  1. Ulnar nerve palsy after closed forearm fracture: a case report

    Directory of Open Access Journals (Sweden)

    Levent Kucuk

    2012-04-01

    Full Text Available Closed double bone forearm fractures are among the most common fractures of childhood. These fractures often heal without problems with closed reduction and casting. The leading complications are known as malunion and compartment syndrome. The reports about nerve injuries related with these fractures are very limited. We present an eight years old boy who admitted to our hospital with ulnar nerve palsy symptomps three months after his initial trauma. His initial trauma was a simple fall which caused radius and ulna fractures. Radiological assessment showed proper union of the fractures. We performed surgical exploration to the ulnar nerve. We found a trapped and damaged nerve in the fracture region. Even though the rate of complications about nerve injuries are extremely rare in forearm fractures, neurologic examinations should be performed before and after the reduction maneuvers. Neurologic examination will be not only a guide for fracture management but also an important point for medicolegal problems. [Hand Microsurg 2012; 1(1.000: 30-32

  2. A Rare Nasal Bone Fracture: Anterior Nasal Spine Fracture

    Directory of Open Access Journals (Sweden)

    Egemen Kucuk

    2014-04-01

    Full Text Available Anterior nasal spine fractures are a quite rare type of nasal bone fractures. Associated cervical spine injuries are more dangerous than the nasal bone fracture. A case of the anterior nasal spine fracture, in a 18-year-old male was presented. Fracture of the anterior nasal spine, should be considered in the differential diagnosis of the midface injuries and also accompanying cervical spine injury should not be ignored.

  3. Hydraulic Fracture Containment in Sand

    NARCIS (Netherlands)

    Dong, Y.

    2010-01-01

    The mechanism of hydraulic fracturing in soft, high permeability material is considered fundamentally different from that in hard, low permeability rock, where a tensile fracture is created and conventional linear elastic fracture mechanics (LEFM) applies. The fracturing and associated modeling work

  4. Impact of Stress on Anomalous Transport in Fractured Rock

    Science.gov (United States)

    Kang, P. K.; Lei, Q.; Lee, S.; Dentz, M.; Juanes, R.

    2016-12-01

    Fluid flow and transport in fractured rock controls many natural and engineered processes in the subsurface. However, characterizing flow and transport through fractured media is challenging due to the large heterogeneity of fractured rock properties. In addition to these "static" challenges, geologic fractures are always under significant overburden stress, and changes in the stress state can lead to changes in the fracture's ability to conduct fluids. While confining stress has been shown to impact fluid flow through fractures in a fundamental way, the impact of confining stress on transport through fractured rock remains largely unexplored. The link between anomalous (non-Fickian) transport and confining stress has been shown only recently, at the level of a single rough fracture [1]. Here, we investigate the impact of confining stress on flow and transport through discrete fracture networks. We model geomechanical effects in 2D fractured rock by means of a finite-discrete element method (FEMDEM), which can capture the deformation of matrix blocks, reactivation and propagation of cracks. We implement a joint constitutive model within the FEMDEM framework to simulate the effect of fracture roughness. We apply the model to a fracture network extracted from the geological map of an actual outcrop to obtain the aperture field at different stress conditions (Figure 1). We then simulate fluid flow and particle transport through the stressed fracture networks. We observe that anomalous transport emerges in response to confining stress on the fracture networks, and show that this anomalous behavior can be linked to the stress state of the rock. Finally, we develop an effective transport model that captures the anomalous transport through stressed fractures. Our results point to a heretofore unrecognized link between geomechanics and anomalous transport in discrete fractured networks. [1] P. K. Kang, S. Brown, and R. Juanes, Emergence of anomalous transport in stressed

  5. Isolated Sternal Fracture. A Case Report

    Directory of Open Access Journals (Sweden)

    Yovanny Ferrer Lozano

    2014-12-01

    Full Text Available Isolated sternal fractures are rare; there are few reports in the medical literature. This article discusses the diagnosis and treatment of a patient who attended the emergency department because of a direct trauma to the anterior chest caused by a car accident. After the diagnosis of isolated sternal fracture, a conservative treatment was adopted. The clinical course was satisfactory until hospital discharge and during the following nine months, the patient remained asymptomatic. The literature on the subject was located and reviewed to support and comment on the case. It is concluded that conservative treatment can lead to consolidation and no sequelae such as pain or different degrees of disability related to the fracture.

  6. Leading Cities

    DEFF Research Database (Denmark)

    Pogner, Karl-Heinz

    2017-01-01

    and technical engineering; Smart Cities) is very prominent in the traditional mass media discourse, in PR / PA of tech companies and traditional municipal administrations; whereas the second one (participation; Livable Cities) is mostly enacted in social media, (local) initiatives, movements, (virtual......) communities, new forms of urban governance in municipal administration and co-competitive city networks. Both forms seem to struggle for getting voice and power in the discourses, negotiations, struggles, and conflicts in Urban Governance about the question how to manage or lead (in) a city. Talking about...

  7. Paediatric talus fracture.

    LENUS (Irish Health Repository)

    Byrne, Ann-Maria

    2012-01-01

    Paediatric talus fractures are rare injuries resulting from axial loading of the talus against the anterior tibia with the foot in dorsiflexion. Skeletally immature bone is less brittle, with higher elastic resistance than adult bone, thus the paediatric talus can sustain higher forces before fractures occur. However, displaced paediatric talus fractures and those associated with high-energy trauma have been associated with complications including avascular necrosis, arthrosis, delayed union, neurapraxia and the need for revision surgery. The authors present the rare case of a talar neck fracture in a skeletally immature young girl, initially missed on radiological review. However, clinical suspicion on the part of the emergency physician, repeat examination and further radiographic imaging revealed this rare paediatric injury.

  8. Geothermal Ultrasonic Fracture Imager

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, Doug [Baker-Hughes Oilfield Operation Inc., Houston, TX (United States); Leggett, Jim [Baker-Hughes Oilfield Operation Inc., Houston, TX (United States)

    2013-07-29

    The Geothermal Ultrasonic Fracture Imager project has a goal to develop a wireline ultrasonic imager that is capable of operating in temperatures up to 300°C (572°F) and depths up to 10 km (32,808 ft). This will address one of the critical needs in any EGS development of understanding the hydraulic flow paths in the reservoir. The ultrasonic imaging is well known in the oil and gas industry as one of the best methods for fracture evaluation; providing both high resolution and complete azimuthal coverage of the borehole. This enables fracture detection and characterization, both natural and induced, providing information as to their location, dip direction and dip magnitude. All of these factors are critical to fully understand the fracture system to enable the optimization of the thermal drainage through injectors and producers in a geothermal resource.

  9. Clavicle Fracture (Broken Collarbone)

    Science.gov (United States)

    ... Bahk MS, Kuhn JE, Galatz LM, Connor PM, Williams GR: Acromioclavicular and sternoclavicular injuries and cla- vicular, ... Orthopaedic Surgeons. .org Clavicle Fracture cont. Rehabilitation Specific exercises will help restore movement and strengthen your shoulder. ...

  10. Proximal femoral fractures

    DEFF Research Database (Denmark)

    Palm, Henrik; Teixidor, Jordi

    2015-01-01

    BACKGROUND: In hip fracture surgery, the exact choice of implant often remains somewhat unclear for the individual surgeon, but the growing literature consensus has enabled publication of evidence-based surgical treatment pathways. The aim of this article was to review author pathways and national...... guidelines for hip fracture surgery and discuss a method for future pathway/guideline implementation and evaluation. METHODS: By a PubMed search in March 2015 six studies of surgical treatment pathways covering all types of proximal femoral fractures with publication after 1995 were identified. Also we...... searched the homepages of the national heath authorities and national orthopedic societies in West Europe and found 11 national or regional (in case of no national) guidelines including any type of proximal femoral fracture surgery. RESULTS: Pathway consensus is outspread (internal fixation for un...

  11. MRI of subchondral fractures: a review

    Energy Technology Data Exchange (ETDEWEB)

    Lopes Viana, Sergio [Hospital Ortopedico e Medicina Especializada (HOME) and Hospital da Crianca de Brasilia Jose Alencar, Brasilia, DF (Brazil); Beber Machado, Bruno [Clinica Radiologica Med Imagem, Unimed Sul Capixaba and Santa Casa de Misericordia de Cachoeiro de Itapemirim, Cachoeiro de Itapemirim (Brazil); Mendlovitz, Paulo Sergio [Hospital Universitario de Brasilia (Universidade de Brasilia) and Radiologia Anchieta, Brasilia (Brazil)

    2014-11-15

    Several authors have recently emphasized the role of magnetic resonance imaging (MRI) in the diagnosis of subchondral fractures. There is increasing interest about this type of fractures, mostly because they have been implicated in the genesis of some well-known destructive articular conditions whose cause was previously undetermined, such as distal clavicular osteolysis, rapidly progressive osteoarthritis of the hip, spontaneous osteonecrosis of the knee and adult-type Freiberg's infraction. Subchondral fractures may ultimately lead to bone collapse, secondary osteonecrosis and severe articular damage, and there may be rapid progression of joint destruction over a period of weeks to months. It has been suggested that timely diagnosis might potentially improve the outcome and avoid the onset of destructive joint disease, making MRI even more important in this setting. The fracture line usually appears as a band of low signal intensity in the subchondral bone plate, adjacent to the articular surface, most often surrounded by bone marrow edema. In this article the authors review the most relevant imaging features of subchondral fractures in several joints, stressing the importance of early recognition for a better outcome. (orig.)

  12. Fracture Behavior under Impact.

    Science.gov (United States)

    1982-07-01

    discussed for the different loading rates ob- tai ned . 1. Introduction In static fracture mechanics crack tip stress intensity factors can easi- - ly...deviation to the left or to the right hand side of the original crack path was observed. Herrmann [151 speculated that this behavior results from stress...Materials’ Draft 2c, American Society for Testing and Materials, Philadelphia, .. ,-- 1980. 15. Herrmann , G., "Dynamic Fracture of Beams in Bending

  13. Relative permeability through fractures

    Energy Technology Data Exchange (ETDEWEB)

    Diomampo, Gracel, P.

    2001-08-01

    The mechanism of two-phase flow through fractures is of importance in understanding many geologic processes. Currently, two-phase flow through fractures is still poorly understood. In this study, nitrogen-water experiments were done on both smooth and rough parallel plates to determine the governing flow mechanism for fractures and the appropriate methodology for data analysis. The experiments were done using a glass plate to allow visualization of flow. Digital video recording allowed instantaneous measurement of pressure, flow rate and saturation. Saturation was computed using image analysis techniques. The experiments showed that gas and liquid phases flow through fractures in nonuniform separate channels. The localized channels change with time as each phase path undergoes continues breaking and reforming due to invasion of the other phase. The stability of the phase paths is dependent on liquid and gas flow rate ratio. This mechanism holds true for over a range of saturation for both smooth and rough fractures. In imbibition for rough-walled fractures, another mechanism similar to wave-like flow in pipes was also observed. The data from the experiments were analyzed using Darcy's law and using the concept of friction factor and equivalent Reynold's number for two-phase flow. For both smooth- and rough-walled fractures a clear relationship between relative permeability and saturation was seen. The calculated relative permeability curves follow Corey-type behavior and can be modeled using Honarpour expressions. The sum of the relative permeabilities is not equal one, indicating phase interference. The equivalent homogeneous single-phase approach did not give satisfactory representation of flow through fractures. The graphs of experimentally derived friction factor with the modified Reynolds number do not reveal a distinctive linear relationship.

  14. Atomistic simulations of fracture

    Energy Technology Data Exchange (ETDEWEB)

    Farkas, D. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Materials Science and Engineering

    1997-12-31

    Embedded atom interaction potentials are used to simulate the atomistic aspects of the fracture process. Simulations are presented for the behavior of cracks in pure metals and intermetallics, near the Griffith condition. The materials considered include Fe, Cu, Ni as well as Fe, Ni, Co, and Ti aluminides. The work focuses on the comparative study of fracture behavior in the different materials. The role of the atomic relaxation at the crack tip and of lattice trapping phenomena is analyzed.

  15. Science of Fracture.

    Science.gov (United States)

    1980-10-22

    Fracture Set-Up .............. 163 Dr. Jan T. Lindt 4.i0 Fracture in Fully Plastic Bodies ............................... 171 Dr. Howard Kuhn iii I...Benthem’s results and results obtained by 15 Bazant and Estenssoro (12) who used a finite element method of determining critical eigenvalues. Each of...14) is made by Benthem in (10) and (11) and only che sentence quoted above made by Bazant and Estenssoro (12). This is unfortunate since constructive

  16. Field fracturing multi-sites project. Annual report, August 1, 1995--July 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    The objective of the Field Fracturing Multi-Sites Project (M-Site) is to conduct experiments to definitively determine hydraulic fracture dimensions using remote well and treatment well diagnostic techniques. In addition, experiments are to be conducted to provide data that will resolve significant unknowns with regard to hydraulic fracture modeling, fracture fluid rheology and fracture treatment design. These experiments will be supported by a well-characterized subsurface environment, as well as surface facilities and equipment conducive to acquiring high-quality data. The primary Project goal is to develop a fully characterized, tight reservoir-typical, field-scale hydraulic fracturing test site to diagnose, characterize, and test hydraulic fracturing technology and performance. It is anticipated that the research work being conducted by the multi-disciplinary team of GRI and DOE contractors will lead to the development of a commercial fracture mapping tool/service.

  17. Subduction of fracture zones

    Science.gov (United States)

    Constantin Manea, Vlad; Gerya, Taras; Manea, Marina; Zhu, Guizhi; Leeman, William

    2013-04-01

    Since Wilson proposed in 1965 the existence of a new class of faults on the ocean floor, namely transform faults, the geodynamic effects and importance of fracture zone subduction is still little studied. It is known that oceanic plates are characterized by numerous fracture zones, and some of them have the potential to transport into subduction zones large volumes of water-rich serpentinite, providing a fertile water source for magma generated in subduction-related arc volcanoes. In most previous geodynamic studies, subducting plates are considered to be homogeneous, and there is no clear indication how the subduction of a fracture zone influences the melting pattern in the mantle wedge and the slab-derived fluids distribution in the subarc mantle. Here we show that subduction of serpentinized fracture zones plays a significant role in distribution of melt and fluids in the mantle wedge above the slab. Using high-resolution tree-dimensional coupled petrological-termomechanical simulations of subduction, we show that fluids, including melts and water, vary dramatically in the region where a serpentinized fracture zone enters into subduction. Our models show that substantial hydration and partial melting tend to concentrate where fracture zones are being subducted, creating favorable conditions for partially molten hydrous plumes to develop. These results are consistent with the along-arc variability in magma source compositions and processes in several regions, as the Aleutian Arc, the Cascades, the Southern Mexican Volcanic Arc, and the Andean Southern Volcanic Zone.

  18. Prevention of hip fractures.

    Science.gov (United States)

    Meunier, P J

    1993-11-30

    For a 50-year old Caucasian woman today, the risk of a hip fracture over her remaining life-time is about 17%. Tomorrow the situation will clearly be worse because the continuous increase in life expectancy will cause a three-fold increase in worldwide fracture incidence over the next 60 years. Through diagnostic bone mass measurements at the hip and assessment of biochemical parameters, a great deal has been learned in recent years about reduction of hip fracture risk. Preventive strategies are based on prevention of falls, use of hip protectors, and prevention of bone fragility. The latter includes the optimization of peak bone mass during childhood, postmenopausal estrogen replacement therapy, and also late prevention consisting in reversing senile secondary hyperparathyroidism, which plays an important role in the decrease of skeletal strength. This secondary hyperparathyroidism, which results from both vitamin D insufficiency and low calcium intake, is preventable with vitamin D3 and calcium supplements. They have recently been shown capable of providing effective prevention of hip fractures in elderly women living in nursing homes, with a reduction of about 25% in the number of hip fractures noted in a 3-year controlled study in 3,270 women (intention-to-treat analysis). In conclusion, it is never too early to reduce the risk of osteoporosis and never too late to prevent hip fractures.

  19. FRACTURING FLUID CHARACTERIZATION FACILITY

    Energy Technology Data Exchange (ETDEWEB)

    Subhash Shah

    2000-08-01

    Hydraulic fracturing technology has been successfully applied for well stimulation of low and high permeability reservoirs for numerous years. Treatment optimization and improved economics have always been the key to the success and it is more so when the reservoirs under consideration are marginal. Fluids are widely used for the stimulation of wells. The Fracturing Fluid Characterization Facility (FFCF) has been established to provide the accurate prediction of the behavior of complex fracturing fluids under downhole conditions. The primary focus of the facility is to provide valuable insight into the various mechanisms that govern the flow of fracturing fluids and slurries through hydraulically created fractures. During the time between September 30, 1992, and March 31, 2000, the research efforts were devoted to the areas of fluid rheology, proppant transport, proppant flowback, dynamic fluid loss, perforation pressure losses, and frictional pressure losses. In this regard, a unique above-the-ground fracture simulator was designed and constructed at the FFCF, labeled ''The High Pressure Simulator'' (HPS). The FFCF is now available to industry for characterizing and understanding the behavior of complex fluid systems. To better reflect and encompass the broad spectrum of the petroleum industry, the FFCF now operates under a new name of ''The Well Construction Technology Center'' (WCTC). This report documents the summary of the activities performed during 1992-2000 at the FFCF.

  20. [Subtrochanteric femoral fractures].

    Science.gov (United States)

    Ulmar, B; Simon, S; Eschler, A; Mittlmeier, T

    2013-12-01

    Subtrochanteric femoral fractures are proximal femoral fractures which are located between the trochanter minor and an area of 3 cm below the minor trochanter on the femoral shaft. About 10-15% of all proximal femoral fractures correspond to this fracture site. Elderly or geriatric patients are generally affected and the injury is often the result of a fall in the home, while high-energy trauma is the cause in a small group of generally younger patients. Clinical evaluation of the affected extremity shows disability of axial weight-bearing and pain during compression and rotation of the hip joint. Basic diagnostics include conventional x-rays of the injured femur in the anterior-posterior and lateral planes. These subtrochanteric femoral fractures are almost always treated surgically due to the inherent high degree of instability. The main goals of surgical intervention are to achieve anatomic fracture reduction and primary full weight-bearing stability of the corresponding leg. Intramedullary interlocking nails are used for primary treatment, while extramedullary implants are often used in revision surgery. Early mobilization and intensive respiratory exercises are necessary to prevent early postoperative complications.

  1. Fracture toughness of graphene.

    Science.gov (United States)

    Zhang, Peng; Ma, Lulu; Fan, Feifei; Zeng, Zhi; Peng, Cheng; Loya, Phillip E; Liu, Zheng; Gong, Yongji; Zhang, Jiangnan; Zhang, Xingxiang; Ajayan, Pulickel M; Zhu, Ting; Lou, Jun

    2014-04-29

    Perfect graphene is believed to be the strongest material. However, the useful strength of large-area graphene with engineering relevance is usually determined by its fracture toughness, rather than the intrinsic strength that governs a uniform breaking of atomic bonds in perfect graphene. To date, the fracture toughness of graphene has not been measured. Here we report an in situ tensile testing of suspended graphene using a nanomechanical device in a scanning electron microscope. During tensile loading, the pre-cracked graphene sample fractures in a brittle manner with sharp edges, at a breaking stress substantially lower than the intrinsic strength of graphene. Our combined experiment and modelling verify the applicability of the classic Griffith theory of brittle fracture to graphene. The fracture toughness of graphene is measured as the critical stress intensity factor of and the equivalent critical strain energy release rate of 15.9 J m(-2). Our work quantifies the essential fracture properties of graphene and provides mechanistic insights into the mechanical failure of graphene.

  2. Importance of greenstick lamina fractures in low lumbar burst fractures

    Science.gov (United States)

    Ersozlu, S.; Aydinli, U.

    2006-01-01

    Lumbar burst fractures (L3–L5) represent a small percentage of all spinal fractures. The treatment of fractures involving the lumbar spine has been controversial. Lamina fractures may be complete or of the greenstick type. Dural tears and nerve root entrapment may accompany these lamina fractures. The aim of this retrospective study was to determine the incidence of dural tear in patients who had lumbar burst fractures with greenstick lamina fractures and the importance of these lamina fractures when choosing the optimum treatment. Twenty-six patients with 28 lumbar burst fractures were treated from 1995 through 2002. The average follow-up was 60 months (range 32–110 months). The male to female ratio was 21:5 and the mean age was 37 years (17–64). Dural tear was detected in seven (25%) out of 28 burst fractures. The functional outcome of the entire study group was assessed using the Smiley-Webster Scale. Good to excellent results were obtained in 24 (92%) of 26 patients. Lumbar burst fractures with greenstick lamina fractures occur mostly in the L2–L4 area. In the surgical treatment, any reduction manoeuvre will close the fracture and crush the entrapped neural elements. Therefore, it may be better to explore the greenstick lamina fracture whether there is any neural entrapment or not, before any reduction manoeuvre is attempted. PMID:16501977

  3. Evaluating and mitigating fracture risk in established rheumatoid arthritis.

    Science.gov (United States)

    Mullen, Matthew B; Saag, Kenneth G

    2015-01-01

    Patients with rheumatoid arthritis are predisposed to systemic bone loss, and they are at an increased risk of fractures. Although there are similarities in the patient demographics between rheumatoid arthritis patients and the general population of osteoporosis patients, there are factors, particularly the use of glucocorticoids, which are specific to rheumatoid arthritis. These factors can lead to an increased risk of bone loss and fracture. Given that fractures are often very debilitating, especially in elderly patients, it is of paramount importance for the practicing rheumatologist to be aware of ways to reduce the risk of fracture in patients with rheumatoid arthritis. This review discusses currently available modalities for fracture risk assessment as well as pharmacologic and lifestyle interventions available to treat and prevent bone loss in rheumatoid arthritis patients.

  4. The epidemiology of fractures in Denmark in 2011

    DEFF Research Database (Denmark)

    Driessen, J H M; Hansen, L; Eriksen, S A

    2016-01-01

    UNLABELLED: In the present study, we used national health care databases to estimate fracture incidence rates (IRs) and compared these IRs based on imputed data. We showed that imputation could lead to both over- and underestimation of IRs, and future research should therefore focus on how...... to improve those imputations. INTRODUCTION: Osteoporosis is a major public health burden through associated (osteoporotic) fractures. In Denmark, the incidence rates (IRs) of hip fracture are widely available. However, there is limited data about other fracture sites. A recent report could only provide...... imputed IRs, although nationwide data is readily available in electronic healthcare databases. Therefore, our aim was to estimate fracture site-specific IRs for Denmark in 2011 and to compare those to the previously reported imputed data. METHODS: Data from the Danish National Hospital Discharge Register...

  5. CT of pelvic fractures

    Energy Technology Data Exchange (ETDEWEB)

    Falchi, Marco E-mail: marcofalchi@yahoo.it; Rollandi, Gian Andrea

    2004-04-01

    Although magnetic resonance imaging has become the dominant modality for cross-sectional musculo-skeletal imaging, the widespread availability, speed, and versatility of computed tomography (CT) continue to make it a mainstay of emergency room (ER) diagnostic imaging. Pelvic ring and acetabular fractures occur as the result of significant trauma secondary to either a motor vehicle accident or a high-velocity fall. These injuries are correlated with significant morbidity and mortality, both from the complications of pelvic ring fractures and from commonly associated injuries. The most commonly used classification of pelvic and acetabular fractures has been based on conventional radiographs that are, in the majority of cases, sufficient to determine the type of injury. However, because of the complexity of pelvic and acetabular fractures, precise pathological anatomy is not easily demonstrated by routine radiographs and in many cases details of fractures are not visible. Moreover, the insufficient co-operation of the patient or the difficulty of maintaining special positions can be overcome by using computed tomography. Spiral computed tomography provides information regarding the extent of the fractures and is complementary to radiography for ascertaining the spatial arrangement of fracture fragments. Spiral computed tomography is an effective tool for understanding complex fracture patterns, particularly when combined with multi-planar reconstruction two-dimensional (MPR 2D) reformatted images or three-dimensional images (3D) images. Including these techniques of reconstruction in routine pelvic imaging protocols can change management in a significant number of cases. Subtle fractures, particularly those oriented in the axial plane, are better seen on MPR images or 3D volume-rendered images. Complex injuries can be better demonstrated with 3D volume-rendered images, and complicated spatial information about the relative positions of fracture fragments can be easily

  6. Post-operative stress fractures complicating surgery for painful forefoot conditions.

    Science.gov (United States)

    Edwards, Max R; Jack, Christopher; Jones, Gareth G; Singh, Samrendu K

    2010-01-01

    A stress fracture is caused by repetitive or unusual loading of a bone leading to mechanical failure. Fatigue type stress fractures occur in normal bone exposed to abnormally high repetitive loads, whereas insufficiency type stress fractures occur in abnormal bone exposed to normal loads. We describe three cases of insufficiency stress fractures that have complicated surgery for painful forefoot conditions. The diagnosis and management of these cases are discussed. Stress fractures should be included in the differential diagnosis of any patient who continues or develops pain after surgery to the forefoot.

  7. Unusual Unilateral Fracture of the Condylar and Coronoid Processes of the Mandible

    Directory of Open Access Journals (Sweden)

    Timucin Baykul

    2014-01-01

    Full Text Available The incidence of condylar fracture is very high and most are not caused by direct trauma. On the other hand, fracture of the coronoid process is reported less often than fracture of other parts of the mandible. We report a case of right subcondylar and coronoid fractures without any evidence of direct trauma to the zygomatic area or an indirect trauma to the mandibular corpus or sypmheseal region. The possible cause was identified as acute reflex contraction of the temporalis muscles leading to coronoid and condylar stress fractures.

  8. Predicting Hip Fracture Type With Cortical Bone Mapping (CBM) in the Osteoporotic Fractures in Men (MrOS) Study.

    Science.gov (United States)

    Treece, Graham M; Gee, Andrew H; Tonkin, Carol; Ewing, Susan K; Cawthon, Peggy M; Black, Dennis M; Poole, Kenneth E S

    2015-11-01

    Hip fracture risk is known to be related to material properties of the proximal femur, but fracture prediction studies adding richer quantitative computed tomography (QCT) measures to dual-energy X-ray (DXA)-based methods have shown limited improvement. Fracture types have distinct relationships to predictors, but few studies have subdivided fracture into types, because this necessitates regional measurements and more fracture cases. This work makes use of cortical bone mapping (CBM) to accurately assess, with no prior anatomical presumptions, the distribution of properties related to fracture type. CBM uses QCT data to measure the cortical and trabecular properties, accurate even for thin cortices below the imaging resolution. The Osteoporotic Fractures in Men (MrOS) study is a predictive case-cohort study of men over 65 years old: we analyze 99 fracture cases (44 trochanteric and 55 femoral neck) compared to a cohort of 308, randomly selected from 5994. To our knowledge, this is the largest QCT-based predictive hip fracture study to date, and the first to incorporate CBM analysis into fracture prediction. We show that both cortical mass surface density and endocortical trabecular BMD are significantly different in fracture cases versus cohort, in regions appropriate to fracture type. We incorporate these regions into predictive models using Cox proportional hazards regression to estimate hazard ratios, and logistic regression to estimate area under the receiver operating characteristic curve (AUC). Adding CBM to DXA-based BMD leads to a small but significant (p fracture, with AUC increasing from 0.78 to 0.79, assessed using leave-one-out cross-validation. For specific fracture types, the improvement is more significant (p fractures and 0.76 to 0.82 for femoral neck fractures. In contrast, adding DXA-based BMD to a CBM-based predictive model does not result in any significant improvement. © 2015 The Authors. Journal of Bone and Mineral Research published by

  9. Veining Failure and Hydraulic Fracturing in Shales

    Science.gov (United States)

    Mighani, S.; Sondergeld, C. H.; Rai, C. S.

    2014-12-01

    During the hydraulic fracturing, the pressurized fluid creates new fractures and reactivates existing natural fractures forming a highly conductive Stimulated Reservoir Volume (SRV) around the borehole. We extend the previous work on Lyons sandstone and pyrophyllite to anisotropic shale from the Wolfcamp formation. We divide the rock anisotropy into two groups: a) conventional and b) unconventional (shaly) anisotropy. X-ray Computed Tomography (CT), compressional velocity anisotropy, and SEM analysis are used to identify three causes of anisotropy: bedding planes, clay lamination, and calcite veins. Calcite vein is a subsequently filled with calcite bonded weakly to the matrix. Velocity anisotropy and visual observations demonstrate the calcite filled veins to be mostly subparallel to the fabric direction. Brazilian tests are carried out to observe the fracture initiation and propagation under tension. High speed photography (frame rate 300,000 frame/sec) was used to capture the failure. Strain gauges and Acoustic Emission (AE) sensors recorded the deformation leading up to and during failure. SEM imaging and surface profilometry were employed to study the post-failure fracture system and failed surface topology. Fracture permeability was measured as a function of effective stress. Brazilian tests on small disks containing a centered single vein revealed the shear strength of the veins. We interpret the strain data and number, frequency, and amplitude of AE events which are correlated well with the observed fracture process zone, surface roughness, and permeability. The unpropped fracture has enhanced permeability by two orders of magnitude. The observed anisotropic tensile failure seems to have a universal trend with a minimum strength occurring at 15o orientation with respect to the loading axis. The veins at 15o orientation with respect to the loading axis were easily activated at 30% of the original failure load. The measured strength of the vein is as low as 6

  10. Prevalence of dementia in elderly patients with hip fracture.

    Science.gov (United States)

    Yiannopoulou, Konstantina G; Anastasiou, Ioannis P; Ganetsos, Theodore K; Efthimiopoulos, Petros; Papageorgiou, Sokratis G

    2012-01-01

    Hip fractures occur commonly and are a cause of disability for older adults and lead to increased dependence and requirements for social support. Dementia is one of the possible risk factors for falling and hip fracture, a potential source for complications during surgery and during the postoperative period, difficulties in rehabilitation and a risk factor for hip fracture reccurence. However, in previous studies of hip fracture patients, cognitive status has not been formally assessed during the inpatient stay and diagnosis was based only on previous history. Additionally, no previous studies have compared prevalence of dementia between elderly patients with hip fracture and patients with other surgical pathology. Our aim was to define whether dementia was more prevalent in older subjects with hip fracture than in other elderly patients undergoing surgery. In this study, we prospectively assessed all patients aged 68 and older admitted to our hospital for hip fracture surgery during a one year period and compared them with age and gender matched patients attending other surgical departments. 80 hip fracture patients and 80 controls were assessed for dementia. Dementia was common in both groups, presumably reflecting the advanced mean age of both groups and cognitive deterioration due to hospitalization-status. Dementia was significantly higher in the hip fracture group (85%) compared to the control group (61.5%; p=0.002). Dementia is very common in older patients admitted for surgery to a general hospital and extremely common in those with hip fracture. It seems that dementia is under diagnosed in elderly hospitalised patients. Our data confirm that dementia is a major risk factor for hip fracture in the elderly.

  11. Preliminary experience with biodegradable implants for fracture fixation

    Directory of Open Access Journals (Sweden)

    Dhillon Mandeep

    2008-01-01

    Full Text Available Background: Biodegradable implants were designed to overcome the disadvantages of metal-based internal fixation devices. Although they have been in use for four decades internationally, many surgeons in India continue to be skeptical about the mechanical strength of biodegradable implants, hence this study. Materials and Methods: A prospective study was done to assess the feasibility and surgeon confidence level with biodegradable implants over a 12-month period in an Indian hospital. Fifteen fractures (intra-articular, metaphyseal or small bone fractures were fixed with biodegradable implants. The surgeries were randomly scheduled so that different surgeons with different levels of experience could use the implants for fixation. Results: Three fractures (one humeral condyle, two capitulum, were supplemented by additional K-wires fixation. Trans-articular fixator was applied in two distal radius and two pilon fractures where bio-pins alone were used. All fractures united, but in two cases the fracture displaced partially during the healing phase; one fibula due to early walking, and one radius was deemed unstable even after bio-pin and external fixator. Conclusions: Biodegradable -implants are excellent for carefully selected cases of intra-articular fractures and some small bone fractures. However, limitations for use in long bone fractures persist and no great advantage is gained if a "hybrid" composite is employed. The mechanical properties of biopins and screws in isolation are perceived to be inferior to those of conventional metal implants, leading to low confidence levels regarding the stability of reduced fractures; these implants should be used predominantly in fracture patterns in which internal fixation is subjected to minimal stress.

  12. Hydraulic Fracturing and the Environment

    Science.gov (United States)

    Ayatollahy Tafti, T.; Aminzadeh, F.; Jafarpour, B.; de Barros, F.

    2013-12-01

    In this presentation, we highlight two key environmental concerns of hydraulic fracturing (HF), namely induced seismicity and groundwater contamination (GC). We examine the induced seismicity (IS) associated with different subsurface fluid injection and production (SFIP) operations and the key operational parameters of SFIP impacting it. In addition we review the key potential sources for possible water contamination. Both in the case of IS and GC we propose modeling and data analysis methods to quantify the risk factors to be used for monitoring and risk reduction. SFIP include presents a risk in hydraulic fracturing, waste water injection, enhanced oil recovery as well as geothermal energy operations. Although a recent report (NRC 2012) documents that HF is not responsible for most of the induced seismicities, we primarily focus on HF here. We look into vaious operational parameters such as volume and rate of water injection, the direction of the well versus the natural fracture network, the depth of the target and the local stress field and fault system, as well as other geological features. The latter would determine the potential for triggering tectonic related events by small induced seismicity events. We provide the building blocks for IS risk assessment and monitoring. The system we propose will involve adequate layers of complexity based on mapped seismic attributes as well as results from ANN and probabilistic predictive modeling workflows. This leads to a set of guidelines which further defines 'safe operating conditions' and 'safe operating zones' which will be a valuable reference for future SFIP operations. We also illustrate how HF can lead to groundwater aquifer contamination. The source of aquifer contamination can be the hydrocarbon gas or the chemicals used in the injected liquid in the formation. We explore possible pathways of contamination within and discuss the likelihood of contamination from each source. Many of the chemical compounds used

  13. 10-year probability of major osteoporotic fractures and hip fractures according to Ukrainian model of FRAX® in women with vertebral fractures

    Directory of Open Access Journals (Sweden)

    N.V. Grygorieva

    2017-06-01

    Full Text Available Background. Vertebral fractures are one of the severe complications of systemic osteoporosis, which lead to the low-back pain, decrease or loss of efficiency and increase of mortality in older people. FRAX and dual-energy X-ray absorptiometry (DXA are important methods in determining major osteoporotic fractures risk, including vertebral fractures. Materials and methods. We studied the parameters of Ukrainian model of FRAX in women depending on the presence of vertebral fractures. 652 patients aged 40–89 years examined at the Ukrainian Scientific Medical Center of Osteoporosis were divided into two groups: the first one — 523 women without any previous fractures, the second one — 129 patients with previous vertebral fractures. The assessment of bone mineral density (BMD was performed using DXA (Prodigy, General Electric. The 10-year probability of major osteoporotic fractures (FRAX-MOF and hip fractures (FRAX-HF has been determined using Ukrainian model of FRAX according to two methods — with body mass index (FRAXBMI and BMD. Results. According the distribution of FRAXBMI-MOF parameters in women depending on the presence of vertebral fractures, it was found that index of FRAXBMI-MOF was less than 20 % (the limit indicated as the criterion for treatment initiation in US guidelines in 100 and 100 % of subjects, respectively. The indices of FRAX BMD-HF were less than 3 % (the limit for starting treatment in US guidelines in 95 and 55 % of women, respectively. It was shown the significant moderate correlation between the indices of two methods in all groups for both parameters of the algorithm — FRAX-MOF and FRAX-HF. Conclusions. The study of the age-specific features of FRAX in women depending on the presence of vertebral fractures showed a significant increase in the risks for both major osteoporotic and hip fractures, regardless of the used technique (with BMI or BMD in women with vertebral fractures or without any fractures. Our

  14. Stress generation and hierarchical fracturing in reactive systems

    Science.gov (United States)

    Jamtveit, B.; Iyer, K.; Royne, A.; Malthe-Sorenssen, A.; Mathiesen, J.; Feder, J.

    2007-12-01

    Hierarchical fracture patterns are the result of a slowly driven fracturing process that successively divides the rocks into smaller domains. In quasi-2D systems, such fracture patterns are characterized by four sided domains, and T-junctions where new fractures stop at right angles to pre-existing fractures. We describe fracturing of mm to dm thick enstatite layers in a dunite matrix from the Leka ophiolite complex in Norway. The fracturing process is driven by expansion of the dunite matrix during serpentinization. The cumulative distributions of fracture lengths show a scaling behavior that lies between a log - normal and power law (fractal) distribution. This is consistent with a simple fragmentation model in which domains are divided according to a 'top hat' distribution of new fracture positions within unfractured domains. Reaction-assisted hierarchical fracturing is also likely to be responsible for other (3-D) structures commonly observed in serpentinized ultramafic rocks, including the mesh-textures observed in individual olivine grains, and the high abundance of rectangular domains at a wide range of scales. Spectacular examples of 3-D hierarchical fracture patterns also form during the weathering of basaltic intrusions (dolerites). Incipient chemical weathering of dolerites in the Karoo Basin in South Africa occurs around water- filled fractures, originally produced by thermal contraction or by externally imposed stresses. This chemical weathering causes local expansion of the rock matrix and generates elastic stresses. On a mm to cm scale, these stresses lead to mechanical layer-by-layer spalling, producing the characteristic spheroidal weathering patterns. However, our field observations and computer simulations demonstrate that in confined environments, the spalling process alone is unable to relieve the elastic stresses. In such cases, chemical weathering drives a much larger scale hierarchical fracturing process in which fresh dolerite undergoes a

  15. [Fracture of macroporous hydroxyapatite prosthesis].

    Science.gov (United States)

    Adetchessi, A T; Pech-Gourg, G; Metellus, P; Fuentes, S

    2012-12-01

    Different prosthesis implants are offered to perform a cranioplasty after a decompressive craniectomy when autologous bone graft cannot be used. The authors report the case of a 25-year-old man who benefited a unilateral decompressive craniectomy after a severe head trauma. Seven months later, a cranioplasty using custom macroporous hydroxyapatite prosthesis was performed. The postoperative course was marked by a generalized seizure leading to a traumatic head injury. The CT-scan showed a comminutive fracture of the prosthesis and an extradural hematoma. The patient underwent a removal of the fractured prosthesis and an evacuation of the extradural clot. The postoperative course was uneventful with a Glasgow outcome scale score at 5. A second cranioplasty using a polyether ether ketone (PEEK) implant was performed. Among cranioplasty prosthesis solutions, hydroxyapatite implants seem to have similar property to the bone. However, its weak mechanic resistance is an actual problem in patients susceptible to present generalized seizures with consecutive head impact. Hence, in patients with decompressive craniectomy who are exposed to potential brain injury, we favor the use of more resistant implant as PEEK prosthesis.

  16. CT classification of acetabular fractures

    Energy Technology Data Exchange (ETDEWEB)

    Marincek, B.; Porcellini, B.; Robotti, G.

    1984-05-01

    The contribution of computed tomography (CT) in classifying acetabular fractures was analysed retrospectively in 33 cases. CT and plain radiography classification agreed in 27 cases (82%). CT revealed more extensive fractures in 6 patients (thereof 5 patients with associated fractures). In 10 patients (thereof 9 patients with associated fractures) CT showed intraarticular fragments; radiographically intraarticular fragments were seen only in 2 patients and suspected in 4. CT is of considerable aid in defining the fracture pattern. It should be used mainly in patients with radiographically difficult interpretable associated fractures in order to assess preoperatively the weight-bearing part of the acetabulum, the degree of displacement and the presence of intraarticular fragments.

  17. Atomistic Simulations of Nanotube Fracture

    CERN Document Server

    Belytschko, T; Schatz, G; Ruoff, R S

    2002-01-01

    The fracture of carbon nanotubes is studied by atomistic simulations. The fracture behavior is found to be almost independent of the separation energy and to depend primarily on the inflection point in the interatomic potential. The rangle of fracture strians compares well with experimental results, but predicted range of fracture stresses is marketly higher than observed. Various plausible small-scale defects do not suffice to bring the failure stresses into agreement with available experimental results. As in the experiments, the fracture of carbon nanotubes is predicted to be brittle. The results show moderate dependence of fracture strength on chirality.

  18. [Humeral shaft fractures].

    Science.gov (United States)

    Schittko, A

    2004-08-01

    Since Lorenz Böhler postulated in his 1964 summary with the title "Against the operative treatment of fresh humeral shaft fractures" that the operative treatment is the exception in the therapy of humeral fractures times have changed. In the last years a conservative treatment of a humeral fracture is the exception and only used after straight indications. The operative therapy nowadays is the gold standard because of the development of new intramedullar and rotation stable implants in addition to the classical osteosynthesis with the plate. But even the external fixator for primary stabilisation in polytrauma patients or as rescue procedure after complications should be in repertory of every orthopedic surgeon. Attention should be put on the avoidance of primary and the correct treatment of secondary nerval lesions, esp. of the radial nerve. Here we are tending to the operative revision of the nerve in indistinct cases. In the treatment of the seldom humeral shaft fracture of the child conservative treatment is to prefer; in complications a resolute shift to a final operative stabilisation of the fracture is necessary.

  19. Fracture-Flow-Enhanced Solute Diffusion into Fractured Rock

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yu-Shu; Ye, Ming; Sudicky, E.A.

    2007-12-15

    We propose a new conceptual model of fracture-flow-enhanced matrix diffusion, which correlates with fracture-flow velocity, i.e., matrix diffusion enhancement induced by rapid fluid flow within fractures. According to the boundary-layer or film theory, fracture flow enhanced matrix diffusion may dominate mass-transfer processes at fracture-matrix interfaces, because rapid flow along fractures results in large velocity and concentration gradients at and near fracture-matrix interfaces, enhancing matrix diffusion at matrix surfaces. In this paper, we present a new formulation of the conceptual model for enhanced fracture-matrix diffusion, and its implementation is discussed using existing analytical solutions and numerical models. In addition, we use the enhanced matrix diffusion concept to analyze laboratory experimental results from nonreactive and reactive tracer breakthrough tests, in an effort to validate the new conceptual model.

  20. Bona-fide, strong-variable galactic Luminous Blue Variable stars are fast rotators: detection of a high rotational velocity in HR Carinae

    CERN Document Server

    Groh, Jose H; Hillier, D John; Barba, Rodolfo; Fernandez-Lajus, Eduardo; Gamen, Roberto C; Moises, Alessandro; Solivella, Gladys; Teodoro, Mairan

    2009-01-01

    We report optical observations of the Luminous Blue Variable (LBV) HR Carinae which show that the star has reached a visual minimum phase in 2009. More importantly, we detected absorptions due to Si IV 4088-4116 Angstroms. To match their observed line profiles from 2009 May, a high rotational velocity of vrot=150 +- 20 km/s is needed (assuming an inclination angle of 30 degrees), implying that HR Car rotates at ~0.88 +- 0.2 of its critical velocity for break-up (vcrit). Our results suggest that fast rotation is typical in all strong-variable, bona-fide galactic LBVs, which present S Dor-type variability. Strong-variable LBVs are located in a well-defined region of the HR diagram during visual minimum (the "LBV minimum instability strip"). We suggest this region corresponds to where vcrit is reached. To the left of this strip, a forbidden zone with vrot/vcrit>1 is present, explaining why no LBVs are detected in this zone. Since dormant/ex LBVs like P Cygni and HD 168625 have low vrot, we propose that LBVs can ...

  1. Stress fracture of the proximal fibula after total knee arthroplasty.

    Science.gov (United States)

    Vaish, Abhishek; Vaishya, Raju; Agarwal, Amit Kumar; Vijay, Vipul

    2016-04-22

    We report a rare case of proximal fibular fatigue fracture developing 14 years after total knee arthroplasty in a known case of rheumatoid arthritis. A valgus deformity of the knee can put abnormal stress on the upper fibula leading to its failure. We believe that, as the fibula acts as an important lateral strut, its disruption due to a fracture led to rapid progress of the valgus deformity of the knee in this patient.

  2. Reducing missing fracture clinic radiographs by entrusting them to patients.

    OpenAIRE

    Calder, Peter R.; Hynes, Matthew C.; Goodier, W. David

    2004-01-01

    BACKGROUND: Missing radiographs in fracture clinics may compromise fracture management and lead to inappropriate use of clerical resources. METHODS: We prospectively compared the number of missing radiographs in two hospitals over a period of two months. In hospital A the radiographs were retained and in hospital B they were entrusted to the patients. RESULTS: At the completion of the study, entrusting patients with their radiographs resulted in statistically less radiographs missing from the...

  3. HIGHER VISCOSITY OF LOGWAY FRACTURE FOR WIRE DRAWING

    OpenAIRE

    V. N. Kovalevsky; D. G. Sachava

    2009-01-01

    The paper presents results of the investigations on evaluation of logway resistance which are used for drawing cord wire made of tungsten-containing hard alloy. It has been shown that complicated loading conditions lead to fracture of a tool surface and these conditions are attributed to the action of various mechanisms: wearing due to high local stresses and deformations, fracture due to stretching stresses at logway expansion, small-cycle fatigue, heat shock etc. It is proposed to evaluate ...

  4. Transstyloid, transscaphoid, transcapitate fracture: a variant of scaphocapitate fractures.

    LENUS (Irish Health Repository)

    Burke, Neil G

    2014-01-01

    Transstyloid, transscaphoid, transcapitate fractures are uncommon. We report the case of a 28-year-old man who sustained this fracture following direct trauma. The patient was successfully treated by open reduction internal fixation of the scaphoid and proximal capitate fragment, with a good clinical outcome at 1-year follow-up. This pattern is a new variant of scaphocapitate fracture as involves a fracture of the radial styloid as well.

  5. Maxillofacial Fractures: Its features and Occurrence in Western Uttar Pradesh,India- A Retrospective Study.

    Directory of Open Access Journals (Sweden)

    Dr. Swapnil S. Bumb

    2013-12-01

    Full Text Available Introduction: The successful surgical treatment of maxillofacial fractures consists of early recognition of fractured site, etiologic factors and demographic patterns. In Western Uttar Pradesh, Road Traffic Accidents are leading cause of maxillofacial fractures followed by facial assault. Mandibular fractures followed by upper face fractures are the leading causes of maxillofacial fractures. Aims and Objectives: The aim of this retrospective study is to investigate the pattern of maxillofacial fractures in western Uttar Pradesh, India. Material & Methods: This study is conducted at Teerthankar Mahaveer Medical College & Research Center and associated Teerthankar Mahaveer Dental College & Research Center, TMU are situated on Moradabad –Delhi national highway. Most patients admitted here were referral patients from adjacent territory. Results: There were about 76% cases of mandibular and 24% cases of mid-face fractures. Among mid-face fractures Zygoma fractures constituted about 35.5% cases. Male to female ratio was found to be 3.5:1. Conclusion: In conclusion, it seems that RTAs remain the biggest etiological factor of maxillofacial fractures in (Western Uttar Pradesh India.

  6. Vertebral Geometry Parameters Can Predict Fractures

    Directory of Open Access Journals (Sweden)

    P Tofighi

    2007-01-01

    Conclusion: Vertebral fractures are common fractures in postmenopausal women. There was a correlation between verte¬bral height and fractures. Vertebral geometric parameters especially height T score can be used for fracture screening.

  7. Galeazzi fractures and dislocations.

    Science.gov (United States)

    Giannoulis, Filippos S; Sotereanos, Dean G

    2007-05-01

    In 1934, fractures of the middle and distal third of the radius associated with instability of the distal radial ulnar joint (DRUJ) were described by Galeazzi. This type of lesion is characterized by its unstable nature and the need for open reduction and internal fixation to achieve a satisfactory functional outcome. A high index of suspicion should be maintained by the surgeon, and a thorough examination for instability of the DRUJ must be conducted. The marked instability of this fracture-dislocation complex is further enhanced by the disruption of the triangular fibrocartilage complex, either with or without ulna styloid fracture. Treatment in adults is surgical, and both bone and soft tissue injuries should be addressed.

  8. DEM Particle Fracture Model

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Boning [Univ. of Colorado, Boulder, CO (United States); Herbold, Eric B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Homel, Michael A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Regueiro, Richard A. [Univ. of Colorado, Boulder, CO (United States)

    2015-12-01

    An adaptive particle fracture model in poly-ellipsoidal Discrete Element Method is developed. The poly-ellipsoidal particle will break into several sub-poly-ellipsoids by Hoek-Brown fracture criterion based on continuum stress and the maximum tensile stress in contacts. Also Weibull theory is introduced to consider the statistics and size effects on particle strength. Finally, high strain-rate split Hopkinson pressure bar experiment of silica sand is simulated using this newly developed model. Comparisons with experiments show that our particle fracture model can capture the mechanical behavior of this experiment very well, both in stress-strain response and particle size redistribution. The effects of density and packings o the samples are also studied in numerical examples.

  9. Complications of mandibular fractures.

    Science.gov (United States)

    Zweig, Barry E

    2009-03-01

    Before any definitive treatment of mandibular fractures, the patient needs to be evaluated for more potentially life-threatening injuries. Complications can and do occur with treatment of mandibular fractures and can occur during any of the phases of treatment. The development of an accurate diagnosis and appropriate treatment plan is vital in achieving optimal success and decreasing complications. Knowledge of the anatomy and the principles of bone healing is also an important factor in preventing complications. To limit long-term untoward effects, complications should be recognized early and the appropriate treatment should be started before a minor complication becomes a complex one that is more difficult to manage.

  10. [Supracondylar fractures in children].

    Science.gov (United States)

    Petrov, N; Gucev, S; Kirkov, Lj; Dajljevik, S; Ruso, B

    1982-01-01

    In the Department of Pediatric surgery, during the last ten years, 190 patients with supracondylar fractures (second and third degree, according to Bauman's classification) have been treated. The operation was performed in only 5% of all hospitalized cases. There were only one patient with neurological and vascular complications in the early stage, but without any complications in the late stage. The presented cases showed a high percentage of flexion type of fractures. The conservative treatment by a reposition has given the most satisfactory results.

  11. Distal Radius Fracture (Broken Wrist)

    Science.gov (United States)

    .org Distal Radius Fracture (Broken Wrist) Page ( 1 ) The radius is the larger of the two bones of the forearm. The ... the distal end. A fracture of the distal radius occurs when the area of the radius near ...

  12. Colles wrist fracture – aftercare

    Science.gov (United States)

    ... www.ncbi.nlm.nih.gov/pubmed/21228899 . Prawer A. Radius and ulna fractures. In: Eiff MP, Hatch RL, eds. Fracture Management for Primary Care . 3rd ed. Philadelphia, PA: Elsevier Saunders; 2011:chap ...

  13. Fracture After Total Hip Replacement

    Science.gov (United States)

    ... osteolysis. Symptoms The most common symptoms of periprosthetic hip fracture include: • Pain around the hip or thigh • Swelling ... o en very painful, someone with a periprosthetic hip fracture will most likely go directly to the emergency ...

  14. A retrospective study of temporomandibular joint ankylosis secondary to surgical treatment of mandibular condylar fractures.

    Science.gov (United States)

    Xiang, Guo-lin; Long, Xing; Deng, Mo-hong; Han, Qian-chao; Meng, Qing-gong; Li, Bo

    2014-03-01

    We investigated the incidence of ankylosis of the temporomandibular joint (TMJ) after open operations for fractures of the mandibular condyle, and analysed possible risk factors in a total of 385 patients with 492 condylar fractures who had been operated on in our department from 2001 to 2010. Sixteen patients developed postoperative ankylosis of the TMJ with 26 joints (5%) affected during a follow-up of 6 months-10 years. Of the 492 condylar fractures, the most common ones that were associated with postoperative ankylosis were those of the condylar head (20/248), followed by the condylar neck (6/193). Subcondylar fractures did not cause postoperative ankylosis (0/51). Among the 16 patients with postoperative ankylosis, 13 had associated anterior mandibular fractures. Long-screw (bicortical screw) fixation of fractures of the condylar head seemed to be associated with a lower incidence of postoperative ankylosis than fixation by miniplate and wire or removal of the fractured fragment. The articular discs were damaged in all ankylosed joints, and the remaining fractured fragment was found in 10 ankylosed joints after fractures of the condylar head. The results suggest that fractures of the condylar head are more prone to lead to postoperative ankylosis of the TMJ, and that the possible risk factors seem to include the technique used for fixation and damage to the disc, together with an anterior mandibular fracture with the fractured fragment remaining.

  15. Sacral Insufficiency Fractures: Recognition and Treatment in Patients with Concurrent Lumbar Vertebral Compression Fractures

    Science.gov (United States)

    Granville, Michelle; Jacobson, Robert E; Berti, Aldo

    2017-01-01

    Introduction In reviewing a larger group of osteoporotic vertebral compression fractures (VCFs), we found that the overall incidence of sacral insufficiency fractures (SIFs) is higher than commonly reported values. This is especially seen in patients with previous or concurrent lumbar VCFs and also in a subgroup that had lumbar stenosis or hip arthroplasty. The altered biomechanics due to associated lumbar stenosis or hip arthroplasty lead to increased mechanical stress on already weakened and deficient sacral alae, which are more vulnerable to osteoporotic weakening than other parts of the sacrum. Materials & methods We studied an overall population of patients with VCF seen clinically and separated the patients into the following groups: patients not previously treated, patients treated with vertebroplasty or kyphoplasty at one or more levels, and patients diagnosed with sacral fractures and treated with vertebroplasty or kyphoplasty. We wanted to see if a pattern existed among the patients who had sacral symptoms, were diagnosed with sacral insufficiency fractures, and subsequently underwent sacroplasty. Results In a review of 79 consecutive patients, over a 24-month period, with VCF who underwent surgical treatment, there were 10 patients who also had sacral insufficiency fractures. Four of the patients had sacral insufficiency fractures without VCF. None of the patients with sacral insufficiency fractures were on treatment for osteoporosis at the time of diagnosis. The following symptoms indicated SIF: lower sacral pain (n = 10), buttock pain (n = 7), lateral hip pain (n = 5), and groin pain radiating to the thigh (n = 4). The average time to diagnose SIF was two months after the onset of pain. Conclusions Sacral insufficiency fractures are a frequent cause of both acute and chronic pain; however, they are often missed by the majority of physicians. The frequency of undetected sacral fractures is high. This is due to a number of potential pitfalls

  16. Simulation of Solute Flow and Transport in a Geostatistically Generated Fractured Porous System

    Science.gov (United States)

    Assteerawatt, A.; Helmig, R.; Haegland, H.; Bárdossy, A.

    2007-12-01

    Fractured aquifer systems have provided important natural resources such as petroleum, gas, water and geothermal energy and have also been recently under investigation for their suitability as storage sites for high-level nuclear waste. The resource exploitation and potential utilization have led to extensive studies aiming of understanding, characterizing and finally predicting the behavior of fractured aquifer systems. By applying a discrete model approach to study flow and transport processes, fractures are determined discretely and the effect of individual fractures can be explicitly investigated. The critical step for the discrete model is the generation of a representative fracture network since the development of flow paths within a fractured system strongly depends on its structure. The geostatistical fracture generation (GFG) developed in this study aims to create a representative fracture network, which combines the spatial structures and connectivity of a fracture network, and the statistical distribution of fracture geometries. The spatial characteristics are characterized from indicator fields, which are evaluated from fracture trace maps. A global optimization, Simulated annealing, is utilized as a generation technique and the spatial characteristics are formulated to its objective function. We apply the GFG to a case study at a Pliezhausen field block, which is a sandstone of a high fracture density. The generated fracture network from the GFG are compared with the statistically generated fracture network in term of structure and hydraulic behavior. As the GFG is based on a stochastic concept, several realizations of the same descriptions can be generated, hence, an overall behavior of the fracture-matrix system have to be investigated from various realizations which leads to a problem of computational demand. In order to overcome this problem, a streamline method for a solute transport in a fracture porous system is presented. The results obtained

  17. Microcracks and Overpressure- Induced Fractures

    Institute of Scientific and Technical Information of China (English)

    Ahmed M. Al - QAHTANI

    2001-01-01

    The microfractures and natural fractures studies have a great significance in the hydrocarbon accumulation exploration and can be a good supporter for wide geophysical study on the major structures. This paper is a brief review on microcracks and overpressure- induced fracture. It is to discuss different views on the mechanism of fractures in the subsurface of the earth.

  18. Diagnosis and Management of Vertebral Compression Fractures.

    Science.gov (United States)

    McCarthy, Jason; Davis, Amy

    2016-07-01

    Vertebral compression fractures (VCFs) are the most common complication of osteoporosis, affecting more than 700,000 Americans annually. Fracture risk increases with age, with four in 10 white women older than 50 years experiencing a hip, spine, or vertebral fracture in their lifetime. VCFs can lead to chronic pain, disfigurement, height loss, impaired activities of daily living, increased risk of pressure sores, pneumonia, and psychological distress. Patients with an acute VCF may report abrupt onset of back pain with position changes, coughing, sneezing, or lifting. Physical examination findings are often normal, but can demonstrate kyphosis and midline spine tenderness. More than two-thirds of patients are asymptomatic and diagnosed incidentally on plain radiography. Acute VCFs may be treated with analgesics such as acetaminophen, nonsteroidal anti-inflammatory drugs, narcotics, and calcitonin. Physicians must be mindful of medication adverse effects in older patients. Other conservative therapeutic options include limited bed rest, bracing, physical therapy, nerve root blocks, and epidural injections. Percutaneous vertebral augmentation, including vertebroplasty and kyphoplasty, is controversial, but can be considered in patients with inadequate pain relief with nonsurgical care or when persistent pain substantially affects quality of life. Family physicians can help prevent vertebral fractures through management of risk factors and the treatment of osteoporosis.

  19. Management of orbital fractures: challenges and solutions

    Directory of Open Access Journals (Sweden)

    Boyette JR

    2015-11-01

    Full Text Available Jennings R Boyette,1 John D Pemberton,2 Juliana Bonilla-Velez1 1Department of Otolaryngology-Head and Neck Surgery, 2Department of Ophthalmology, University of Arkansas for Medical Sciences, Little Rock, AR, USA Abstract: Many specialists encounter and treat orbital fractures. The management of these fractures is often challenging due to the impact that they can have on vision. Acute treatment involves a thorough clinical examination and management of concomitant ocular injuries. The clinical and radiographic findings for each individual patient must then be analyzed for the need for surgical intervention. Deformity and vision impairment can occur from these injuries, and while surgery is intended to prevent these problems, it can also create them. Therefore, surgical approach and implant selection should be carefully considered. Accurate anatomic reconstruction requires complete assessment of fracture margins and proper implant contouring and positioning. The implementation of new technologies for implant shaping and intraoperative assessment of reconstruction will hopefully lead to improved patient outcomes. Keywords: orbital fracture, orbital blowout, orbital floor

  20. Fracture Propagation Driven by Fluid Outflow from a Low-permeability Reservoir

    CERN Document Server

    Gor, Gennady Yu

    2012-01-01

    Fracturing of the caprock during CO2 storage in deep saline aquifers can lead to leakage. Estimation of the rate of fracture propagation allows one to assess the leakage risk. Here we propose an analytical model for calculating the length of the fracture, which propagates due to the fluid outflow from a low-permeability aquifer. We present a self-similar solution of the pressure diffusion equation in the system of reservoir and fracture, allowing us to get the analytical expression for the fracture length as a function of time. We calculate the evolution of the fracture length for a characteristic aquifer. We show that the analytical solution provides an estimate from below for the fracture length, since the driving force for propagation grows with elevation.

  1. P-wave attenuation anisotropy in TI media and its application in fracture parameters inversion

    Science.gov (United States)

    He, Yi-Yuan; Hu, Tian-Yue; He, Chuan; Tan, Yu-Yang

    2016-12-01

    The existence of aligned fractures in fluid-saturated rocks leads to obvious attenuation anisotropy and velocity anisotropy. Attenuation anisotropy analysis can be applied to estimate fracture density and scale, which provide important information for reservoir identification. This paper derives P-wave attenuation anisotropy in the ATI media where the symmetry axis is in the arbitrary direction theoretically and modifies the spectral ratio method to measure attenuation anisotropy in the ATI media, thus avoiding a large measurement error when applied to wide azimuth or full azimuth data. Fracture dip and azimuth can be estimated through attenuation anisotropy analysis. For small-scale fractures, fracture scale and fracture density can be determined with enhanced convergence if velocity and attenuation information are both used. We also apply the modified spectralratio method to microseismic field data from an oilfield in East China and extract the fracture dip through attenuation anisotropy analysis. The result agrees with the microseismic monitoring.

  2. Geomechanically Coupled Simulation of Flow in Fractured Reservoirs

    Science.gov (United States)

    Barton, C.; Moos, D.; Hartley, L.; Baxter, S.; Foulquier, L.; Holl, H.; Hogarth, R.

    2012-12-01

    between wells. More specifically, fractures can hydraulically open or close due to a decrease (caused by injection) or increase (caused by production) in the effective stress. Flow properties are a function of effective fracture aperture, so it is possible to predict reservoir behavior using the relationship between the mechanical behavior of natural fractures (in response to in situ stress and pore pressure changes) and their hydraulic properties. Low flow rate injection tests were used to characterize the hydraulic properties of the fractures, their width, stiffness and strength — properties that are often difficult to quantify, leading to large uncertainties in predicted response to stimulation of fractured reservoirs. Flow through the individual fractures which form the connected network was explicitly modeled. Fracture stress sensitivity was coupled to the flow simulation through the DFN with dynamic adjustment of aperture to effective normal and shear stresses (after Moos and Barton 2008) and calibrated with microseismic data (positions and times of events) and injection data (rates and pressures). Available tracer test data were used to validate the flow simulation. The results highlight the importance of combining all available data, including microseismic, wellbore image, and flow and stimulation test data, to determine reservoir flow behavior and its response to stimulation.

  3. Fracture design modelling

    Energy Technology Data Exchange (ETDEWEB)

    Crichlow, H.B.; Crichlow, H.B. (ed.)

    1980-02-07

    A design tool is discussed whereby the various components that enter the design process of a hydraulic fracturing job are combined to provide a realistic appraisal of a stimulation job in the field. An interactive computer model is used to solve the problem numerically to obtain the effects of various parameters on the overall behavior of the system.

  4. Forearm Fractures in Children

    Science.gov (United States)

    ... secure them in place. Your doctor may recommend surgery if: Casts support and protect broken bones while they heal. Reproduced from Pring M, Chambers H: Pediatric forearm fractures. Orthopaedic Knowledge Online Journal 2007; 5(5). Accessed October 2014. • The bone ...

  5. Fracture Toughness Characterization

    Directory of Open Access Journals (Sweden)

    Manuel Beltrán Z

    2014-11-01

    Full Text Available This paper addresses the fracture toughness ( , or also known as critical stress intensity Factor, according to conditions of Lineal Elastic Fracture Mechanics (LEFM. The characterization of the mechanical properties in tensile and fracture toughness of structural steel pipes API-5L used in hydrocarbons transportation was performed. For fracture toughness, the material was tested through fatigue crack propagation on standardized compact specimen (CT according to ASTM E-399 norm. A thickness (B equal to and a crack size (a equal to 0.5w were used. With the porpoise of establishing the adequate conditions at the crack tip, the specimens were subjected to fatigue pre-cracking by application of repeated cycles of load in tensile-tensile and constant load amplitude with a load ratio of R = 0.1. The experimental Compliance method was used based on data obtained from load vs. Crack Mouth Opening Displacement (CMOD. The results show a Stress Intensity factor of 35.88 MPa√m for a 25 mm crack size specimen. The device used for testing is a MTS-810 machine with capacity of 100KN and 6 kHz sampling rate, which meets the conditions of the ASTM E-399 standard. The cracking susceptibility of steel is influenced by the size, morphology and distribution of non-metallic inclusions, thermochemical interaction with the environment and microstructure.

  6. Injection through fractures

    Energy Technology Data Exchange (ETDEWEB)

    Johns, R.A.

    1987-05-01

    Tracer tests are conducted in geothermal reservoirs as an aid in forecasting thermal breakthrough of reinjection water. To interpret tracer tests, mathematical models have been developed based on the various transport mechanisms in these highly fractured reservoirs. These tracer flow models have been applied to interpret field tests. The resulting matches between the model and field data were excellent and the model parameters were used to estimate reservoir properties. However, model fitting is an indirect process and the model's ability to estimate reservoir properties cannot be judged solely on the quality of the match between field data and model predictions. The model's accuracy in determining reservoir characteristics must be independently verified in a closely controlled environment. In this study, the closely controlled laboratory environment was chosen to test the validity and accuracy of tracer flow models developed specifically for flow in fractured rocks. The laboratory tracer tests were performed by flowing potassium iodide (KI) through artificially fractured core samples. The tracer test results were then analyzed with several models to determine which best fit the measured data. A Matrix Diffusion model was found to provide the best match of the tracer experiments. The core properties, as estimated by the Matrix Diffusion model parameters generated from the indirect matching process, were then determined. These calculated core parameters were compared to the measured core properties and were found to be in agreement. This verifies the use of the Matrix Diffusion flow model in estimating fracture widths from tracer tests.

  7. Fracture Mechanics of Concrete

    DEFF Research Database (Denmark)

    Ulfkjær, Jens Peder

    Chapter 1 Chapter l contains the introduction to this thesis. The scope of the thesis is partly to investigate different numerical and analytical models based on fracture mechanical ideas, which are able to predict size effects, and partly to perform an experimental investigation on high-strength......Chapter 1 Chapter l contains the introduction to this thesis. The scope of the thesis is partly to investigate different numerical and analytical models based on fracture mechanical ideas, which are able to predict size effects, and partly to perform an experimental investigation on high......-strength concrete. Chapter 2 A description of the factors which influence the strength and cracking of concrete and high strength concrete is made. Then basic linear fracture mechanics is outlined followed by a description and evaluation of the models used to describe concrete fracture in tension. The chapter ends...... with a description of the different types of size effects. Three examples which discuss the two terms 'size effect' and 'brittleness' and the importance of a stiff test rig. Finally some brittleness numbers are defined. Chapter 3 In chapter 3 the most well-known numerical methods which use the fictitious crack...

  8. 论中国有限公司股权善意取得的一般结构%The General Structure of the Equity Bona Fide Acquisition of Limited Companies in China

    Institute of Scientific and Technical Information of China (English)

    朱晓娟; 姚篮

    2013-01-01

    《公司法司法解释三》的颁布实施,使得对股权善意取得制度的探究从理论延伸到立法,甚至到司法实践的回应与检讨。在肯定股权善意取得制度的存在价值及对有限公司股权善意取得的现行规范进行分析后,认为现行立法并未固定股权流转的模式,这不是法律漏洞,而是在私法自治的精神下还原学说的工具价值。以分离原则为基础解析股权变动的一般结构,是构建股权善意取得一般结构的基础。基于股权的特殊性与商法外观主义设置前置条件、考虑股权善意取得的构成要件并结合当事人是否承认无因性原则来构建股权善意取得的一般结构是非常必要的。%With the promulgation and implementation of Company Law's Judicial Interpretation Three , the academic circles pay attention to The Equity Bona Fide Acquisition from theory to legislation , even to The judicial practice's re-sponse and review .This article admits the value of The Equity Bona Fide Acquisition , and based on analyzing its cur-rent legal norm , thinks that the fact of current legislation's not fixing the mode of equity transferring is not legal loop-hole, but regression of theory's tool value in the spirit of the autonomy of private law .Analyzing general structure of equity transferring on the basis of separation principle , is the basis of constructing general structure of The Equity Bo-na Fide Acquisition .Setting up a precondition based on equity's particularity and appearance doctrine of merchant law, considering constitutive requirements of The Equity Bona Fide Acquisition , and combining with the parties'atti-tude whether admitting No-cause principle or not , are essential to constructing general structure of The Equity Bona Fide Acquisition .

  9. Correlation of hip fracture with other fracture types: Toward a rational composite hip fracture endpoint.

    Science.gov (United States)

    Colón-Emeric, Cathleen; Pieper, Carl F; Grubber, Janet; Van Scoyoc, Lynn; Schnell, Merritt L; Van Houtven, Courtney Harold; Pearson, Megan; Lafleur, Joanne; Lyles, Kenneth W; Adler, Robert A

    2015-12-01

    With ethical requirements to the enrollment of lower risk subjects, osteoporosis trials are underpowered to detect reduction in hip fractures. Different skeletal sites have different levels of fracture risk and response to treatment. We sought to identify fracture sites which cluster with hip fracture at higher than expected frequency; if these sites respond to treatment similarly, then a composite fracture endpoint could provide a better estimate of hip fracture reduction. Cohort study using Veterans Affairs and Medicare administrative data. Male Veterans (n=5,036,536) aged 50-99 years receiving VA primary care between 1999 and 2009 were included. Fractures were ascertained using ICD9 and CPT codes and classified by skeletal site. Pearson correlation coefficients, logistic regression and kappa statistics were used to describe the correlation between each fracture type and hip fracture within individuals, without regard to the timing of the events. 595,579 (11.8%) men suffered 1 or more fractures and 179,597 (3.6%) suffered 2 or more fractures during the time under study. Of those with one or more fractures, the rib was the most common site (29%), followed by spine (22%), hip (21%) and femur (20%). The fracture types most highly correlated with hip fracture were pelvic/acetabular (Pearson correlation coefficient 0.25, pfractures cluster with hip fractures within individuals at greater than expected frequency. If we observe similar treatment risk reductions within that cluster, subsequent trials could consider the use of a composite endpoint to better estimate hip fracture risk. Published by Elsevier Inc.

  10. Simultaneous monteggia type I fracture equivalent with ipsilateral fracture of the distal radius and ulna in a child: a case report

    Directory of Open Access Journals (Sweden)

    Sood Asheesh

    2008-06-01

    Full Text Available Abstract Introduction Simultaneous Monteggia injuries of the elbow and ipsilateral distal radius and ulna fractures are very rare. Case Presentation A unique case of a type I Monteggia fracture equivalent with ipsilateral fracture of the distal radius and ulna (Salter-Harris type II in a child is reported. We describe the management of this unique fracture and discuss the possible mechanism of injury. Conclusion We have highlighted a rare combination of injuries. Early recognition and prompt surgical intervention can lead to a satisfactory outcome even in these complex injuries.

  11. STRESS FRACTURES IN SPORT

    Directory of Open Access Journals (Sweden)

    Đivo Ban

    2009-11-01

    Full Text Available Children and adolescents today, all before starting with regular sports activities and involvement in semi-professional and top professional sport, so it increases the num- ber of discovered stress fractures in this age. This type of injury can occur as a consequence of action one strong force, or the many repeated small force strength, to be exact, when the load (stress transcend ability reparations bones. Stress fractures are recorded and described up to the lower limbs. Research has been confirmed that the bones of lower leg are mostly made in injury, and with the el- derly and with the population of children and young adolescents. Occur in many sports, something to them is greater when the frequency of running and often are present in the female population. According to the results of numerous investigations, mistakes in the training are the most common cause of the emergence of stress fracture. In a direct comparison with complemented these injuries is the condition of muscles, so it is important that at the sa- me time carry out exercises strengthen muscles and stretching. Typical clinical signs of stress fractures are localized painful sensitivity to palpa- tion and runoff in a small number of cases. The basic diagnostic procedure is a medical check, it is the small, radiology and scintigraphyc diagnostics (most accurate and mag- netic resonance imaging. Treatment is usually without surgery and conservative, with rest and reducing stress, and its activity athlete breaks mainly between four and eight weeks. Only the very need surgical treatment The most important thing is that attention is focused on the proper prevention and to take all that it ever occurred to stress fractures that athletes ramble of the courts and the competition (better education of sports workers, separation of groups with increa- sed risk of the formation of an injury, adaptation activities age and abilities of athletes, adequate sports equipment, high-quality sports

  12. WARRIOR-trial - is routine radiography following the 2-week initial follow-up in trauma patients with wrist and ankle fractures necessary : study protocol for a randomized controlled trial

    NARCIS (Netherlands)

    Weil, Nikki L.; Termaat, M. Frank; Rubinstein, Sidney M.; El Moumni, Mostafa; Zuidema, Wietse P.; Derksen, Robert Jan; Krijnen, Pieta; van Bodegom-Vos, Leti; Wendt, Klaus W.; van Kuijk, Cornelis; Rosendaal, Frits R.; Breederveld, Roelf S.; Goslings, J. Carel; Schipper, Inger B.; van Tulder, Maurits W.

    2015-01-01

    Background: Extremity fractures such as wrist and ankle fractures are a common and costly healthcare problem. The management of these fractures depends on fracture type and loss of congruity of the joint, resulting in cast immobilization or operative treatment. Loss of congruity or displacement lead

  13. Treatment of subtrochanteric fracture with femoral interlocked intramedullary pin and rehabilitation exercise%应用股骨交锁髓内钉和康复锻炼治疗股骨粗隆下骨折

    Institute of Scientific and Technical Information of China (English)

    周峰; 姜为民; 唐天驷; 杨惠林

    2002-01-01

    @@ Background: Femoral subtrochanteric fracture means fractures happened 5 cm away from inferior margin level of small trochanter. Most of this kind of fracture is unstable fractures caused by trauma mostly and characterized with large malposition, splintered and difficult to be treated. It will lead to a series of severe complications if treated improperly.

  14. Diplopia and orbital wall fractures.

    Science.gov (United States)

    Boffano, Paolo; Roccia, Fabio; Gallesio, Cesare; Karagozoglu, K Hakki; Forouzanfar, Tymour

    2014-01-01

    Diplopia is a symptom that is frequently associated with orbital wall fractures. The aim of this article was to present the incidence and patterns of diplopia after orbital wall blow-out fractures in 2 European centers, Turin and Amsterdam, and to identify any correlation between this symptom and such fractures. This study is based on 2 databases that have continuously recorded data of patients hospitalized with maxillofacial fractures between 2001 and 2010. On the whole, 447 patients (334 males, 113 females) with pure blow-out orbital wall fractures were included. The most frequently involved orbital site was the floor (359 fractures), followed by medial wall (41 fractures) and lateral wall (5 fractures). At presentation, 227 patients (50.7%) had evidence of diplopia. In particular, in most patients, a diplopia in all directions was referred (78 patients). Statistically significant associations were found between diplopia on eye elevation and orbital floor fractures (P diplopia and medial wall fractures (P diplopia on eye elevation and horizontal diplopia at presentation could be useful clinical indicators orbital floor and medial wall fractures, respectively.

  15. Stress fracture of the distal fibula in flatfoot patients: case report

    OpenAIRE

    Cheng, Yu; Yang, HuiLin; Ni, Li; Song, Dawei; Zhang, Hongtao

    2015-01-01

    The increase in proportional loading of the fibula with progression of hindfoot deformity would lead to high fibular loads during rapid walking, resulting in insufficiency fractures. We report an unusual mechanism of such fracture in a textile worker resulting from valgus alignment from a stage III flatfoot deformity. The stress fracture was missed initially and only confirmed by CT examination. The patient responded well to nonoperative treatment and had an excellent recovery with no residua...

  16. Posterior rib fractures in a young infant who received chiropractic care.

    Science.gov (United States)

    Wilson, Paria Majd; Greiner, Mary V; Duma, Elena M

    2012-11-01

    We report on a 21-day-old infant with healing posterior rib fractures that were noted after a chiropractic visit for colic. Chiropractors are the third largest group of health care professionals in the United States, and colic is the leading complaint for pediatric chiropractic care. Rib fractures, specifically when posterior, are traditionally considered to be secondary to nonaccidental trauma. Thorough investigation is necessary to rule out bone fragility and genetic disorders, but patient history is key when evaluating unexplained fractures.

  17. Internal fixation for coronal shear fracture of the capitellum with polylactide resorbable fixation

    Science.gov (United States)

    Kraan, Gerald A; Krijnen, Matthijs R; Eerenberg, Jan Peter

    2013-01-01

    A 24-year-old woman with pain in the right elbow after a fall demonstrated a coronal shear fracture on radiographic studies. Perioperative a coronal shear fracture was seen and treated successfully with a polylactide Rigid fix resorbable pin. The operative correction resulted in normal function at 6 months follow-up. We state that a capitellum shear fracture can be fixated with a single resorbable pin, leading to successful fusion. PMID:23378544

  18. Scaphoid fractures in the athlete.

    Science.gov (United States)

    Winston, Mark J; Weiland, Andrew J

    2017-03-01

    Scaphoid fractures are a common wrist injury, especially in athletes. Clinicians should have a high index of suspicion for a scaphoid fracture in any patient complaining of radial-sided wrist pain after a fall on an outstretched hand. Advanced imaging, including CT and MRI scans, may be useful in diagnosis and classification of fracture patterns. Treatment varies based on the fracture location, stability of the fracture, and predictability of the fracture to heal. Treatment involves either non-operative management with a thumb spica cast or brace, or operative fixation with a headless compression screw, k-wires, or scaphoid-specific plates. Return to play is dependent on many variables, including sport, fracture union, and ability to play with cast.

  19. Collagen turnover after tibial fractures

    DEFF Research Database (Denmark)

    Joerring, S; Krogsgaard, M; Wilbek, H

    1994-01-01

    Collagen turnover after tibial fractures was examined in 16 patients with fracture of the tibial diaphysis and in 8 patients with fracture in the tibial condyle area by measuring sequential changes in serological markers of turnover of types I and III collagen for up to 26 weeks after fracture...... collagen. A group comparison showed characteristic sequential changes in the turnover of types I and III collagen in fractures of the tibial diaphysis and tibial condyles. The turnover of type III collagen reached a maximum after 2 weeks in both groups. The synthesis of type I collagen reached a maximum...... after 2 weeks in the diaphyseal fractures and after 6 weeks in the condylar fractures. The degradation of type I collagen increased after 4 days and reached a maximum at 2 weeks in both groups. The interindividual variation was wide. On a group basis, the turnover of types I and III collagen had...

  20. Periprosthetic fractures evaluation and treatment.

    Science.gov (United States)

    Masri, Bassam A; Meek, R M Dominic; Duncan, Clive P

    2004-03-01

    Periprosthetic fracture is a serious complication of total hip arthroplasty (THA) that can be difficult to treat, and can be potentially fraught with complications. The incidence of such fractures is increasing, especially after the use of cementless revision arthroplasty. The prevention of these fractures is achieved by understanding the risk factors involved. If the risks are not understood, the best outcome is achieved when the surgeon has a thorough understanding of the principles of treatment of these fractures and has access to various fixation and prosthetic devices, and allograft bone when necessary. Acetabular fractures are rare and relatively little has been reported on their treatment. Periprosthetic femoral fracture treatment is based on the site of fracture, implant stability, and bone stock. The Vancouver classification offers a reproducible description of these factors with the subsequently easy formation of a treatment plan.

  1. [Clinical practice guideline on closed tibial plateau fractures in adulthood].

    Science.gov (United States)

    Ocegueda-Sosa, Miguel Ángel; Valenzuela-Flores, Adriana Abigail; Aldaco-García, Víctor Daniel; Flores-Aguilar, Sergio; Manilla-Lezama, Nicolás; Pérez-Hernández, Jorge

    2013-01-01

    Closed tibiae plateau fractures are common injuries in the emergency room. The optimal treatment is not well defined or established. For this reason, there are several surgical management options: open reduction and internal fixation, closed reduction and percutaneous synthesis, external fixation, and even conservative treatment for this kind of fracture. The mechanism of production of this fracture is through large varus or valgus deformation to which is added a factor of axial load. The trauma may be direct or indirect. The degree of displacement, fragmentation and involvement of soft tissues like ligaments, menisci, vascular and nerve structures are determined by the magnitude of the force exerted. Any intra-articular fracture treatment can lead to an erroneous instability, deformity and limitation of motion with subsequent arthritic changes, leading to joint incongruity, limiting activity and significantly altering the quality of life. Open reduction and internal fixation with anatomic restitution is the method used in this type of fracture. However, the results of numerous publications can be questioned due to the inclusion in the same study of fractures treated with very different methods.

  2. Study on Influence of Mud Pollution on Formation Fracture Pressure

    Directory of Open Access Journals (Sweden)

    Xiao Hui

    2015-01-01

    Full Text Available The mud pollution may change the mechanical properties of rock during oil and gas drilling process, which affects the prediction of fracture pressure, leads to the failure of hydraulic fracturing treatment. Therefore, it is necessary to study influence of mud pollution on formation fracture pressure to improve the forecasting accuracy. The mud pollution has influences on the modulus of elasticity and the Poisson’s ratio of rock by the mud pollution experiment, the core microstructure is observed around the mud pollution. Based on the experiment and research, the effects of mud pollution on the fracturing pressure are studied by finite element software system ANSYS, the factors such as pollution depth, perforation length and Poisson’s ratio of polluted area are taken into account. The result of the experiment indicated that the modulus of elasticity of rock is reduced and the Poisson’s ratio of rock is increased by the mud pollution. Through computing and analyzing, it can be concluded that increases in pollution depth and Poisson’s ratio can lead to a vast increase in formation fracturing pressure. A calculation example is presented and the results show that the results of this research can provide valuable guidance to the designers of hydraulic fracturing treatment.

  3. Fracture Propagation and Permeability Change under Poro-thermoelastic Loads & Silica Reactivity in Enhanced Geothermal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad Ghassemi

    2009-10-01

    Geothermal energy is recovered by circulating water through heat exchange areas within a hot rock mass. Geothermal reservoir rock masses generally consist of igneous and metamorphic rocks that have low matrix permeability. Therefore, cracks and fractures play a significant role in extraction of geothermal energy by providing the major pathways for fluid flow and heat exchange. Therefore, knowledge of the conditions leading to formation of fractures and fracture networks is of paramount importance. Furthermore, in the absence of natural fractures or adequate connectivity, artificial fractures are created in the reservoir using hydraulic fracturing. Multiple fractures are preferred because of the large size necessary when using only a single fracture. Although the basic idea is rather simple, hydraulic fracturing is a complex process involving interactions of high pressure fluid injections with a stressed hot rock mass, mechanical interaction of induced fractures with existing natural fractures, and the spatial and temporal variations of in-situ stress. As a result, it is necessary to develop tools that can be used to study these interactions as an integral part of a comprehensive approach to geothermal reservoir development, particularly enhanced geothermal systems. In response to this need we have developed advanced poro-thermo-chemo-mechanical fracture models for rock fracture research in support of EGS design. The fracture propagation models are based on a regular displacement discontinuity formulation. The fracture propagation studies include modeling interaction of induced fractures. In addition to the fracture propagation studies, two-dimensional solution algorithms have been developed and used to estimate the impact of pro-thermo-chemical processes on fracture permeability and reservoir pressure. Fracture permeability variation is studied using a coupled thermo-chemical model with quartz reaction kinetics. The model is applied to study quartz precipitation

  4. Approach to the Child with Fractures

    Science.gov (United States)

    Boyce, Alison M.

    2011-01-01

    Evaluation of the child with fractures is challenging, as no clear guidelines exist to distinguish traumatic from pathological fractures. Although most fractures in childhood are benign, recurrent fractures may be associated with a wide variety of primary skeletal diseases as well as secondary causes, necessitating a careful history and physical exam to guide the evaluation. There is no “gold standard” for the evaluation and treatment of children with fractures and low bone mineral density (BMD); therefore, the diagnosis of osteoporosis in a pediatric patient should be made using a combination of clinical and radiographic features. Interpretation of bone densitometry in growing patients presents a unique set of challenges because areal BMD measured by dual-energy x-ray absorptiometry depends on multiple dynamic variables. Interpretation of pediatric dual-energy x-ray absorptiometry should be based on Z-scores (sd scores compared to age, sex, and ethnicity-matched controls), using normative databases specific to the brand of densitometer and the patient population. Given the skeleton's ability to recover from low BMD through modeling and remodeling, optimizing management of underlying conditions leading to bone fragility is the initial step. Conservative measures including calcium and vitamin D supplementation and weight-bearing physical activity are important interventions that should not be overlooked. The use of bisphosphonates in children and adolescents is controversial due to lack of long-term efficacy and safety data and should be limited to clinical trials and compassionate therapy in children with significantly compromised quality of life. Close monitoring is required, and further study is necessary to assess their long-term safety and efficacy in children. PMID:21734001

  5. Presentation and outcome of traumatic spinal fractures

    Directory of Open Access Journals (Sweden)

    Ahmed El-Faramawy

    2012-01-01

    Full Text Available Background: Motor vehicle crashes and falls account for most of the spine fractures with subsequent serious disability. Aim: To define the incidence, causes, and outcome of spinal fractures. Materials and Methods: Data were collected retrospectively from trauma registry database of all traumatic spinal injuries admitted to the section of trauma surgery in Qatar from November 2007 to December 2009. Results: Among 3712 patients who were admitted to the section of trauma surgery, 442 (12% injured patients had spinal fractures with a mean age of 33.2 ± 12 years. The male to female ratio was 11.6:1. Motor vehicle crashes (36.5% and falls from height (19.3% were the leading causes of cervical injury (P = 0.001. The injury severity score ranged between 4 and 75. Nineteen percent of cases with cervical injury had thoracic injury as well (P = 0.04. Lumber injury was associated with thoracic injury in 27% of cases (P < 0.001. Combined thoracic and lumber injuries were associated with cervical injury in 33% of cases (P < 0.001. The total percent of injuries associated with neurological deficit was 5.4%. Fifty-three cases were managed surgically for spine fractures; 14 of them had associated neurological deficits. Overall mortalityrate was 5%. Conclusions: Spine fractures are not uncommon in Qatar. Cervical and thoracic spine injuries carry the highest incidence of associated neurological deficit and injuries at other spinal levels. Young males are the most exposed population that deserves more emphasis on injury prevention programs in the working sites and in enforcement of traffic laws.

  6. Surgical Treatment of Displaced Greater Tuberosity Fractures of the Humerus.

    Science.gov (United States)

    Rouleau, Dominique M; Mutch, Jennifer; Laflamme, Georges-Yves

    2016-01-01

    Greater tuberosity fractures of the humerus can be successfully treated nonsurgically in most patients. However, as little as 3 to 5 mm of superior greater tuberosity displacement may adversely affect rotator cuff biomechanics and lead to subacromial impingement in patients who are active. In these cases, surgical treatment is recommended. Multiple surgical techniques include open and arthroscopic options tailored to fracture morphology, and strategies for repair include the use of suture anchors, transosseous sutures, tension bands, and plates/screws. Three classification systems are commonly used to describe greater tuberosity fractures: the AO, Neer, and morphologic classifications. Several hypotheses have been discussed for the mechanism of greater tuberosity fractures and the deforming forces of the rotator cuff, and the use of advanced imaging is being explored.

  7. Salter-Harris fractures 骺离骨折

    Institute of Scientific and Technical Information of China (English)

    初建平

    2012-01-01

    @@ Salter-Harris fractures,.pediatric fractures invo-lving the growth plate (physis) of bones.The majority heal without growth impairment, however some lead to clinically important shortening and angulation.Growth disorders are a result of a destruction of the epiphyseal circulation (inhibits physeal growth) or by formation of a bone bridge across the physis.TypeⅠ:transverse fracture through physis (increased physeal width) (6% ncidence).Healing is rapid,usually within 2~3 weeks, complications are rare.TypeⅡ: Through physis and metaphysic (most common type) (75% incidence).Healing is rapid,and growth is rarely disturbed; an exception to this are fractures of the distal emur and tibia.

  8. Interfacial Fracture of Nanowire Electrodes of Lithium-Ion Batteries

    Science.gov (United States)

    Hardin, G. R.; Zhang, Y.; Fincher, C. D.; Pharr, M.

    2017-06-01

    Nanowires (NW) have emerged as a promising design for high power-density lithium-ion battery (LIB) electrodes. However, volume changes during cycling can lead to fracture of the NWs. In this paper, we investigate a particularly detrimental form of fracture: interfacial detachment of the NW from the current collector (CC). We perform finite element simulations to calculate the energy release rates of NWs during lithiation as a function of geometric parameters and mechanical properties. The simulations show that the energy release rate of a surface crack decreases as it propagates along the NW/CC interface toward the center of the NW. Moreover, this paper demonstrates that plastic deformation in the NWs drastically reduces stresses and thus crack-driving forces, thereby mitigating interfacial fracture. Overall, the results in this paper provide design guidelines for averting NW/CC interfacial fractures during operation of LIBs.

  9. Costal cartilage fractures and disruptions in a rugby football player.

    Science.gov (United States)

    Lopez, Victor; Ma, Richard; Li, Xinning; Steele, John; Allen, Answorth A

    2013-05-01

    Costal cartilage fracture of the rib cage, or costochondral, is a rare sporting injury. For contact athletes, the instability of the rib cage may lead to potential serious complications, similar to rib fractures or thorax disruption. Most authors recommend initial conservative treatment with surgery reserved for only recalcitrant cases. We report a case of an amateur American male rugby football player who sustained a costal cartilage fracture and disruption involving the anterior left fifth and sixth rib costal cartilages. The case highlights the difficulty in establishing the diagnosis based on clinical examination and standard radiographs alone. Computed tomography was used to assist in diagnosing this destabilizing injury to the rib cage. Costal cartilage fractures and disruptions in athletes are rarely reported in the literature and can have serious implications for the athlete's ability to return to play if the rib cage is destabilized.

  10. A case report of missed femoral neck stress fracture

    Directory of Open Access Journals (Sweden)

    Onibere Oruaro Adebayo

    2015-01-01

    Full Text Available Femoral neck stress fracture (FNSF is an uncommon but potentially serious orthopaedic problem. This is a case report on missed femoral neck stress fracture in a 62-year-old female who was initially treated as early-onset coxarthrosis. She later presented to us with a displaced intra-capsular neck of left femur fracture and underwent total hip replacement. This case illustrates that causes other than osteoarthritis should be taken into consideration in patients presenting with anterior hip pain where symptoms are disproportionate to clinical and radiological findings. More advanced investigations such as MRI scan or regular follow up with plain radiographs should be performed. A delay in diagnosis can lead to secondary displacement of the femoral neck stress fracture.

  11. Interfacial Fracture of Nanowire Electrodes of Lithium-Ion Batteries

    Science.gov (United States)

    Hardin, G. R.; Zhang, Y.; Fincher, C. D.; Pharr, M.

    2017-09-01

    Nanowires (NW) have emerged as a promising design for high power-density lithium-ion battery (LIB) electrodes. However, volume changes during cycling can lead to fracture of the NWs. In this paper, we investigate a particularly detrimental form of fracture: interfacial detachment of the NW from the current collector (CC). We perform finite element simulations to calculate the energy release rates of NWs during lithiation as a function of geometric parameters and mechanical properties. The simulations show that the energy release rate of a surface crack decreases as it propagates along the NW/CC interface toward the center of the NW. Moreover, this paper demonstrates that plastic deformation in the NWs drastically reduces stresses and thus crack-driving forces, thereby mitigating interfacial fracture. Overall, the results in this paper provide design guidelines for averting NW/CC interfacial fractures during operation of LIBs.

  12. Ultrasound-Assisted Distal Radius Fracture Reduction

    Science.gov (United States)

    Socransky, Steve; Skinner, Andrew; Bromley, Mark; Smith, Andrew; Anawati, Alexandre; Middaugh, Jeff; Ross, Peter

    2016-01-01

    .42 to 45.7; p < 0.0001). There was no significant difference in the assessment of reduction by PoCUS vs. radiograph. Conclusions PoCUS-guided fracture reduction leads to repeat reduction attempts in approximately 40% of cases and enhances certainty regarding reduction adequacy when the clinical assessment is unclear. PMID:27551652

  13. Deformation and fracture of echinoderm collagen networks

    CERN Document Server

    Ovaska, Markus; Miksic, Amandine; Sugni, Michela; Di Benedetto, Cristiano; Ferrario, Cinzia; Leggio, Livio; Guidetti, Luca; Alava, Mikko J; La Porta, Caterina A M; Zapperi, Stefano

    2016-01-01

    Collagen networks provide the main structural component of most tissues and represent an important ingredient for bio-mimetic materials for bio-medical applications. Here we study the mechanical properties of stiff collagen networks derived from three different echinoderms and show that they exhibit non-linear stiffening followed by brittle fracture. The disordered nature of the network leads to strong sample-to-sample fluctuations in elasticity and fracture strength. We perform numerical simulations of a three dimensional model for the deformation of a cross-linked elastic fibril network which is able to reproduce the macroscopic features of the experimental results and provide insights into the internal mechanics of stiff collagen networks. Our numerical model provides an avenue for the design of collagen membranes with tunable mechanical properties.

  14. Bonded-cell model for particle fracture.

    Science.gov (United States)

    Nguyen, Duc-Hanh; Azéma, Emilien; Sornay, Philippe; Radjai, Farhang

    2015-02-01

    Particle degradation and fracture play an important role in natural granular flows and in many applications of granular materials. We analyze the fracture properties of two-dimensional disklike particles modeled as aggregates of rigid cells bonded along their sides by a cohesive Mohr-Coulomb law and simulated by the contact dynamics method. We show that the compressive strength scales with tensile strength between cells but depends also on the friction coefficient and a parameter describing cell shape distribution. The statistical scatter of compressive strength is well described by the Weibull distribution function with a shape parameter varying from 6 to 10 depending on cell shape distribution. We show that this distribution may be understood in terms of percolating critical intercellular contacts. We propose a random-walk model of critical contacts that leads to particle size dependence of the compressive strength in good agreement with our simulation data.

  15. Vitamin D and fractures: a sistematic review

    Directory of Open Access Journals (Sweden)

    L. Idolazzi

    2011-09-01

    Full Text Available Vitamin D deficiency is a relevant problem particularly in south Europe and in over 65 year old subjects, that is often underestimated. Vitamin D deficiency represents a real medical emergency also for its role in the patho-physiology of muscular-skeletal diseases. Chronic vitamin D deficiency leads to severe bone and muscular outcomes including: osteoporosis, osteomalacia and proximal limb myopathy. These increase the risk of falling and fractures. The efficacy of vitamin D treatment in decreasing the fracture risk has been reporting in several studies. The negative results of some recent studies questioned the clinical vitamin D efficacy. However these studies have a number of methodological problems and even the interpretation of the results is questionable. In this paper we review all these aspects. This analysis permits to confirm that vitamin D treatment can be extremely cost-effective when given to people at high risk of deficiency. An acceptable compliance is obviously of critical importance.

  16. Fracture of sandwiched composites

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Weh-Huei.

    1989-01-01

    Fracture of a pair of collinear cracks in various materials, such as an isotropic strip, an orthotropic strip, a bonded isotropic adhesive layer, and sandwiched orthotropic layers, is investigated. The crack surfaces are subjected to an arbitrary opening pressure p(x). The problems are formulated in terms of Fredholm integral equation of the second kind by making use the techniques of Fourier transform and finite Hilbert transform. In case of uniform opening pressure p(x)={sigma}, exact expressions for the stress intensity factors and the shape of deformed crack are obtained. Numerical calculations are carried out to study the effects of various boundary geometries and material properties on the fracture of the chosen materials.

  17. FRACTURE SHAFT HUMERUS: INTERLOCKING

    Directory of Open Access Journals (Sweden)

    Deepak Kaladagi

    2014-12-01

    Full Text Available BACKGROUND: The incidence of humeral fracture has significantly increased during the present years due to the population growth and road traffic, domestic, industrial, automobile accidents & disasters like tsunami, earthquakes, head-on collisions, polytrauma etc. In order to achieve a stable fixation followed by early mobilization, numerous surgical implants have been devised. PURPOSE: The purpose of this study is to analyze the results of intramedullary fixation of proximal 2/3rd humeral shaft fractures using an unreamed interlocking intramedullary nail. INTRODUCTION: In 40 skeletally matured patients with fracture shaft of humerus admitted in our hospital, we used unreamed antegrade interlocking nails. MATERIAL: We carried out a prospective analysis of 40 patients randomly selected between 2001 to 2014 who were operated at JNMC Belgaum, MMC Mysore & Navodaya Medical College, Raichur. All cases were either RTAs, Domestic, Industrial, automobile accidents & also other modes of injury. METHOD: Routine investigations with pre-anaesthetic check-up & good quality X-rays of both sides of humerus was taken. Time of surgery ranged from 5-10 days from the time of admission. Only upper 1/3rd & middle 1/3rd humeral shaft fractures were included in the study. In all the cases antegrade locked unreamed humeral nails were inserted under C-arm. Patient was placed in supine position & the shoulder was kept elevated by placing a sandbag under the scapula. In all patients incision taken from tip of acromion to 3cm over deltoid longitudinally. Postoperatively sling applied with wrist & shoulder movements started after 24 hours. All the patients ranged between the age of 21-50 years. RESULTS: Total 40 patients were operated. Maximum fracture site were in the middle third- 76%, 14% upper 1/3rd. All 40 patients achieved union. The average time of union was 8-10 weeks. All patients regained full range of movements except in few cases, where there was shoulder

  18. Fracture of brittle solids

    CERN Document Server

    Lawn, Brian

    1993-01-01

    This is an advanced text for higher degree materials science students and researchers concerned with the strength of highly brittle covalent-ionic solids, principally ceramics. It is a reconstructed and greatly expanded edition of a book first published in 1975. The book presents a unified continuum, microstructural and atomistic treatment of modern day fracture mechanics from a materials perspective. Particular attention is directed to the basic elements of bonding and microstructure that govern the intrinsic toughness of ceramics. These elements hold the key to the future of ceramics as high-technology materials--to make brittle solids strong, we must first understand what makes them weak. The underlying theme of the book is the fundamental Griffith energy-balance concept of crack propagation. The early chapters develop fracture mechanics from the traditional continuum perspective, with attention to linear and nonlinear crack-tip fields, equilibrium and non-equilibrium crack states. It then describes the at...

  19. Base fractures of the fifth proximal phalanx can be treated conservatively with buddy taping and immediate mobilisation

    DEFF Research Database (Denmark)

    Vadstrup, Lars S; Jørring, Stig; Bernt, Peter

    2014-01-01

    INTRODUCTION: Treatment of base fractures in the proximal phalanx depends on the fracture type, the degree of displacement and whether fracture reduction is stable or not. Internal fixation often leads to decreased mobility of the injured finger despite exact reduction of the fracture. Our...... treatment is focused upon function and to a lesser extent on exact reposition of the fractured fifth digit. Buddy taping was used after initial, closed reduction of the fracture allowing for immediate mobilisation. MATERIAL AND METHODS: This was a prospective follow-up study of 53 consecutive conservatively...... managed base fractures in 53 patients with a mean age of 39 years. All fractures were treated with buddy taping to the fourth digit and immediate mobilisation. RESULTS: The subjective outcome showed high overall satisfaction, and only four patients reported mild pain at rest or work. Malrotation was noted...

  20. Tibial shaft fracture

    DEFF Research Database (Denmark)

    Larsen, Peter

    IV also showed a significant worse outcome in 3 of the 5 KOOS subscales compared to a reference population at 12-months follow-up. Moreover, this study showed that increasing difference in muscle strength for knee extension between legs was associated with a decreasing QOL. The results of this thesis...... suggested that regaining pre injured QOL and muscle strength following a tibial shaft fracture takes considerable time....

  1. Phase Field Fracture Mechanics.

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Brett Anthony [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    For this assignment, a newer technique of fracture mechanics using a phase field approach, will be examined and compared with experimental data for a bend test and a tension test. The software being used is Sierra Solid Mechanics, an implicit/explicit finite element code developed at Sandia National Labs in Albuquerque, New Mexico. The bend test experimental data was also obtained at Sandia Labs while the tension test data was found in a report online from Purdue University.

  2. Haemodynamically Unstable Pelvic Fractures

    Science.gov (United States)

    2009-01-01

    through the pubic symphysis, and posteriorlywith the sacrum forming the sacroiliac (SI) joints (Fig. 1). The SI joints are the strongest in the body...Gardner MJ, Kendoff D, Ostermeier S, et al. Sacroiliac joint compression using an anterior pelvic compressor: a mechanical study in synthetic bone. J...commonly identified at arteriography.35 Posterior fracture along the SI joints may cause disruption of a main iliac trunk, but is rare, occurring less

  3. Experiment on Hydraulic Fracturing in Rock and Induced Earthquake

    Institute of Scientific and Technical Information of China (English)

    Yan Yuding; Li Yalin; Zhang Zhuan; Ouyang Lisheng; Xie Mingfu

    2005-01-01

    Experiment on rock hydraulic fracturing strength under different confining pressures was conducted on a series of test specimens with various pre-cracks prepared from 7 types of rock.Combining the data of an actual reservoir-induced earthquake with the experimental results of the contemporary tectonic stress field according to the theory of rock strength and the principle and method of rock fracture mechanics, the authors tentatively investigated the earthquakes induced by pore-water pressure in rock and obtained the initial results as follows: ( 1 ) One type of induced earthquake may occur in the case of larger tectonic stress on such weak planes that strike in similar orientation of principle tectonic compressional stress in the shallows of the rock mass; the pore-water pressure σp may generate tensile fracture on them and induce small earthquakes; (2) Two types of induced earthquake may occur in the case of larger tectonic stress, i.e., ① on such weakness planes that strike in similar orientation of principle tectonic compressioual stress, σ1, in the shallows of the rockmass, the pore-water pressure, σp, may generate tensile fracture on them and induce small earthquakes; ② When the tectonic stress approximates the shear strength of the fracture, the pore-water pressure σp may reduce the normal stress, σn, on the fracture face causing failure of the originally stable fracture,producing gliding fracture and thus inducing an earthquake. σp may also increase the fracture depth, leading to an induced earthquake with the magnitude larger than the previous potential magnitude; (3) There is a depth limit for each type of rock mass, and no induced earthquake will occur beyond this limit.

  4. Zoledronic acid and clinical fractures and mortality after hip fracture

    DEFF Research Database (Denmark)

    Lyles, Kenneth W; Colón-Emeric, Cathleen S; Magaziner, Jay S

    2007-01-01

    BACKGROUND: Mortality is increased after a hip fracture, and strategies that improve outcomes are needed. METHODS: In this randomized, double-blind, placebo-controlled trial, 1065 patients were assigned to receive yearly intravenous zoledronic acid (at a dose of 5 mg), and 1062 patients were...... assigned to receive placebo. The infusions were first administered within 90 days after surgical repair of a hip fracture. All patients (mean age, 74.5 years) received supplemental vitamin D and calcium. The median follow-up was 1.9 years. The primary end point was a new clinical fracture. RESULTS......: The rates of any new clinical fracture were 8.6% in the zoledronic acid group and 13.9% in the placebo group, a 35% risk reduction with zoledronic acid (P=0.001); the respective rates of a new clinical vertebral fracture were 1.7% and 3.8% (P=0.02), and the respective rates of new nonvertebral fractures...

  5. Opportunistic Identification of Vertebral Fractures.

    Science.gov (United States)

    Adams, Judith E

    2016-01-01

    Vertebral fractures are powerful predictors of future fracture, so, their identification is important to ensure that patients are commenced on appropriate bone protective or bone-enhancing therapy. Risk factors (e.g., low bone mineral density and increasing age) and symptoms (back pain, loss of height) may herald the presence of vertebral fractures, which are usually confirmed by performing spinal radiographs or, increasingly, using vertebral fracture assessment with dual-energy X-ray absorptiometry scanners. However, a large number (30% or more) of vertebral fractures are asymptomatic and do not come to clinical attention. There is, therefore, scope for opportunistic (fortuitous) identification of vertebral fractures from various imaging modalities (radiographs, computed tomography, magnetic resonance imaging, and radionuclide scans) performed for other clinical indications and which include the spine in the field of view, with midline sagittal reformatted images from computed tomography having the greatest potential for such opportunistic detection. Numerous studies confirm this potential for identification but consistently find underreporting of vertebral fractures. So, a valuable opportunity to improve the management of patients at increased risk of future fracture is being squandered. Educational training programs for all clinicians and constant reiteration, stressing the importance of the accurate and clear reporting of vertebral fractures ("you only see what you look for"), can improve the situation, and automated computer-aided diagnostic tools also show promise to solve the problem of this underreporting of vertebral fractures. Copyright © 2016. Published by Elsevier Inc.

  6. Fracture Networks in Sea Ice

    Directory of Open Access Journals (Sweden)

    Jonas Nesland Vevatne

    2014-04-01

    Full Text Available Fracturing and refreezing of sea ice in the Kara sea are investigated using complex networkanalysis. By going to the dual network, where the fractures are nodes and their intersectionslinks, we gain access to topological features which are easy to measure and hence comparewith modeled networks. Resulting network reveal statistical properties of the fracturing process.The dual networks have a broad degree distribution, with a scale-free tail, high clusteringand efficiency. The degree-degree correlation profile shows disassortative behavior, indicatingpreferential growth. This implies that long, dominating fractures appear earlier than shorterfractures, and that the short fractures which are created later tend to connect to the longfractures.The knowledge of the fracturing process is used to construct growing fracture network (GFNmodel which provides insight into the generation of fracture networks. The GFN model isprimarily based on the observation that fractures in sea ice are likely to end when hitting existingfractures. Based on an investigation of which fractures survive over time, a simple model forrefreezing is also added to the GFN model, and the model is analyzed and compared to the realnetworks.

  7. Fractures of the cervical spine

    Directory of Open Access Journals (Sweden)

    Raphael Martus Marcon

    2013-11-01

    Full Text Available OBJECTIVES: The aim of this study was to review the literature on cervical spine fractures. METHODS: The literature on the diagnosis, classification, and treatment of lower and upper cervical fractures and dislocations was reviewed. RESULTS: Fractures of the cervical spine may be present in polytraumatized patients and should be suspected in patients complaining of neck pain. These fractures are more common in men approximately 30 years of age and are most often caused by automobile accidents. The cervical spine is divided into the upper cervical spine (occiput-C2 and the lower cervical spine (C3-C7, according to anatomical differences. Fractures in the upper cervical spine include fractures of the occipital condyle and the atlas, atlanto-axial dislocations, fractures of the odontoid process, and hangman's fractures in the C2 segment. These fractures are characterized based on specific classifications. In the lower cervical spine, fractures follow the same pattern as in other segments of the spine; currently, the most widely used classification is the SLIC (Subaxial Injury Classification, which predicts the prognosis of an injury based on morphology, the integrity of the disc-ligamentous complex, and the patient's neurological status. It is important to correctly classify the fracture to ensure appropriate treatment. Nerve or spinal cord injuries, pseudarthrosis or malunion, and postoperative infection are the main complications of cervical spine fractures. CONCLUSIONS: Fractures of the cervical spine are potentially serious and devastating if not properly treated. Achieving the correct diagnosis and classification of a lesion is the first step toward identifying the most appropriate treatment, which can be either surgical or conservative.

  8. Fractures of the cervical spine

    Science.gov (United States)

    Marcon, Raphael Martus; Cristante, Alexandre Fogaça; Teixeira, William Jacobsen; Narasaki, Douglas Kenji; Oliveira, Reginaldo Perilo; de Barros Filho, Tarcísio Eloy Pessoa

    2013-01-01

    OBJECTIVES: The aim of this study was to review the literature on cervical spine fractures. METHODS: The literature on the diagnosis, classification, and treatment of lower and upper cervical fractures and dislocations was reviewed. RESULTS: Fractures of the cervical spine may be present in polytraumatized patients and should be suspected in patients complaining of neck pain. These fractures are more common in men approximately 30 years of age and are most often caused by automobile accidents. The cervical spine is divided into the upper cervical spine (occiput-C2) and the lower cervical spine (C3-C7), according to anatomical differences. Fractures in the upper cervical spine include fractures of the occipital condyle and the atlas, atlanto-axial dislocations, fractures of the odontoid process, and hangman's fractures in the C2 segment. These fractures are characterized based on specific classifications. In the lower cervical spine, fractures follow the same pattern as in other segments of the spine; currently, the most widely used classification is the SLIC (Subaxial Injury Classification), which predicts the prognosis of an injury based on morphology, the integrity of the disc-ligamentous complex, and the patient's neurological status. It is important to correctly classify the fracture to ensure appropriate treatment. Nerve or spinal cord injuries, pseudarthrosis or malunion, and postoperative infection are the main complications of cervical spine fractures. CONCLUSIONS: Fractures of the cervical spine are potentially serious and devastating if not properly treated. Achieving the correct diagnosis and classification of a lesion is the first step toward identifying the most appropriate treatment, which can be either surgical or conservative. PMID:24270959

  9. OUTCOME OF LOCKING PLATES IN DISTAL TIBIA FRACTURES TREATMENT

    Directory of Open Access Journals (Sweden)

    Lokesh

    2016-05-01

    Full Text Available INTRODUCTION Most of these fractures except intra-articular fractures are treated with interlocking nail. 1,2 These nails are a boon for these fractures. But as the fracture nears to the joint stability the fracture fixation will be compromised due to malreduction and alignment, it leads to increased chances of delayed and nonunion. 3 Locking anatomical plates are evaluated for anatomical and relative stability fixation. Since then most intra and near intra-articular fractures are fixed with these plates with minimally invasive percutaneous plate osteosynthesis method, these plates have given excellent result 4 . But again these plates have some disadvantages 5 . This study is done to see the outcome of locking plates in distal tibia fracture. METHODS This study is done in the Department of Orthopaedics, Bangalore Medical College, Bangalore. This study is done from 2013 to 2015. 30 patients who came to outpatient department were treated with locking plates. All patients above 16 years having distal third tibia fracture are included. All open fractures except type 1 and elderly above 60 years and pathological fractures are excluded in our study. All patients were followed up for initial 5 months, thereafter, once in 3 months, for clinical and radiological evaluation of union status, knee range of motion, ankle range of motion and other complications. Assessment of the patient with functional recovery was done with American Orthopaedic Foot and Ankle Surgery(AOFAS 6 minimum 5 months after injury. RESULTS Majority of the patients are from age group 18-29 years (50%. Average age group was 30 years. Majority of the patients were males 80.6% (25. All fractures were closed fractures except 2 cases which are type 1. There were 12 cases of AO type A, 8 patients were AO type B and 10 patients were type C. Majority of the patients had fracture due to road traffic accidents, 74%. All fractures were united by the end of 20 weeks. There was delayed union in

  10. Numerical investigation and optimization of multiple fractures in tight gas reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Hou, M.Z. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). ITE; Energie-Forschungszentrum Niedersachsen, Goslar (Germany); Zhou, L. [Energie-Forschungszentrum Niedersachsen, Goslar (Germany)

    2013-08-01

    The main objective of the project DGMK-680 in phase 2 was to investigate the influence of fractures on each other in a multi-fracture system including their space optimization by using the numerical program FLAC3D with our own developments, which treats all fractures in one 3D geometric model under 3D stress state with fully hydro-mechanical coupling effect. The case study was conducted on a horizontal wellbore at location A, which was stimulated hydraulically with a total of eight transverse fractures in summer 2009. Transverse multiple fractures were simulated using the modified continuum method. In the simulation all fractures were generated in one single model, comprising 22 different rock layers. Each layer was assumed to be homogeneous with regard to its rock and hydromechanical parameters. Thus the influence of the individual fractures on each other can be investigated. The simulation procedure applied, which is a consecutive execution ofa hydraulic and a mechanical computation, is the same for all fractures. The only differences are the primary in-situ stresses, the initial pore pressure, the injection parameters (location, rate, volume, duration), which lead to different patterns of fracture propagations. But there are still some common points, such as irregular patterns of the fracture front, which represents the heterogeneity of the model. All fractures (1 to 8) have their fracture average half-length between 70 m to 115 m, height between 93 m to 114 m and average width between 18 mm to 31 mm. The percentage difference of fracture height for individual fractures is obviously smaller than that of the fracture half-lengths, because the fracture barriers at bottom and top limit the fracture propagation in z-direction. Incomparison with the analytical simulator (FracPro) most results match well. Simulation of multiple fractures at location A, with the newly developed algorithms, shows that individual transverse multiple fractures at distances between 100

  11. The epidemic of Hip fractures: Are we on the right track?

    NARCIS (Netherlands)

    K.A. Hartholt (Klaas); C. Oudshoorn (Christian); S.M. Zielinski (Stephanie); P.T.P.W. Burgers (Paul); M.J.M. Panneman (Martien); E.F. van Beeck (Ed); P. Patka (Peter); T.J.M. van der Cammen (Tischa)

    2011-01-01

    textabstractBackground: Hip fractures are a public health problem, leading to hospitalization, long-term rehabilitation, reduced quality of life, large healthcare expenses, and a high 1-year mortality. Especially older adults are at greater risk of fractures than the general population, due to the

  12. Risk Factors for Hip Fracture in Older Men: The Osteoporotic Fractures in Men Study (MrOS).

    Science.gov (United States)

    Cauley, Jane A; Cawthon, Peggy M; Peters, Katherine E; Cummings, Steven R; Ensrud, Kristine E; Bauer, Douglas C; Taylor, Brent C; Shikany, James M; Hoffman, Andrew R; Lane, Nancy E; Kado, Deborah M; Stefanick, Marcia L; Orwoll, Eric S

    2016-10-01

    Almost 30% of hip fractures occur in men; the mortality, morbidity, and loss of independence after hip fractures are greater in men than in women. To comprehensively evaluate risk factors for hip fracture in older men, we performed a prospective study of 5994 men, primarily white, age 65+ years recruited at six US clinical centers. During a mean of 8.6 years of 97% complete follow-up, 178 men experienced incident hip fractures. Information on risk factors including femoral neck bone mineral density (FNBMD) was obtained at the baseline visit. Cox proportional hazards models were used to calculate the hazard ratio (HR) with 95% confidence intervals; Fine and Gray models adjusted for competing mortality risk. Older age (≥75 years), low FNBMD, currently smoking, greater height and height loss since age 25 years, history of fracture, use of tricyclic antidepressants, history of myocardial infarction or angina, hyperthyroidism or Parkinson's disease, lower protein intake, and lower executive function were all associated with an increased hip fracture risk. Further adjustment for competing mortality attenuated HR for smoking, hyperthyroidism, and Parkinson's disease. The incidence rate of hip fracture per 1000 person-years (PY) was greatest in men with FNBMD T-scores hip fracture at rates of 14.52 versus 0.88 per 1000 PY in men age hip fracture. Many of these assessments can easily be incorporated into routine clinical practice and may lead to improved risk stratification. © 2016 American Society for Bone and Mineral Research. © 2016 American Society for Bone and Mineral Research.

  13. Lead extraction. Indications and techniques.

    Science.gov (United States)

    Byrd, C L; Schwartz, S J; Hedin, N

    1992-11-01

    Each of the extraction techniques and their ancillary tools was reported as used successfully; however, until now, no technique has been successful when used in more than a few isolated instances. The technique for intravascular countertraction and the associated tools described in this paper were devised and selected in an attempt to develop one technique to be used on all patients, with all types of leads, and with a very low complication rate. Its versatility permitted single or multiple lead extractions combined with the precision of selecting and extracting a specific lead. In our experience, as well as the experience of others, the techniques described in this paper have proved to be superior by minimizing the inherent risk and morbidity, allowing us to expand the indications for lead removal beyond septicemia and free-floating leads, to include infection, abandonment of pockets, and replacement of malfunctioning or fractured leads. Intravascular countertraction was a consistently safe and efficacious method of removing transvenous pacemaker leads regardless of the duration of the implant, thus permitting extractions in patients not considered candidates for a more extensive surgical procedure. Intravascular countertraction encompasses surgical and fluoroscopic techniques possessed by most physicians experienced in pacemaker and automatic implantable cardioverter defibrillator implants. However, there is a learning curve, predicating caution for the inexperienced physician. In addition, advanced surgical skills may be needed in handling associated conditions such as debridement and primary closure of chronically inflamed tissues, especially in submuscular pockets and sinus tracts in the neck. Although the potential for a cardiovascular complication is small, it does exist, and cardiovascular surgical backup is a recommended precaution.

  14. New propant schedule in hydralic fracturing

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.; Fan, C.

    1981-01-01

    A new proppant schedule is suggested to obtain maximum propping surface area and maximum fracture conductivity near the borehole. The small and middle size sands are suspended in the fracturing fluids under fracturing condition to prop the total fracture surface area created by fracturing. The coarse sands pumped into fracture later deposit in the fracture at the dynamic width near the borehole during fracturing and reach the equilibrium height in the time interval of pumping coarse sands. Thus, fracture conductivity near the borehole is increased. Computer calculation of the sand program, the corresponding fluid program and pumping rates are presented also.

  15. FRACTURED PETROLEUM RESERVOIRS

    Energy Technology Data Exchange (ETDEWEB)

    Abbas Firoozabadi

    1999-06-11

    The four chapters that are described in this report cover a variety of subjects that not only give insight into the understanding of multiphase flow in fractured porous media, but they provide also major contribution towards the understanding of flow processes with in-situ phase formation. In the following, a summary of all the chapters will be provided. Chapter I addresses issues related to water injection in water-wet fractured porous media. There are two parts in this chapter. Part I covers extensive set of measurements for water injection in water-wet fractured porous media. Both single matrix block and multiple matrix blocks tests are covered. There are two major findings from these experiments: (1) co-current imbibition can be more efficient than counter-current imbibition due to lower residual oil saturation and higher oil mobility, and (2) tight fractured porous media can be more efficient than a permeable porous media when subjected to water injection. These findings are directly related to the type of tests one can perform in the laboratory and to decide on the fate of water injection in fractured reservoirs. Part II of Chapter I presents modeling of water injection in water-wet fractured media by modifying the Buckley-Leverett Theory. A major element of the new model is the multiplication of the transfer flux by the fractured saturation with a power of 1/2. This simple model can account for both co-current and counter-current imbibition and computationally it is very efficient. It can be orders of magnitude faster than a conventional dual-porosity model. Part II also presents the results of water injection tests in very tight rocks of some 0.01 md permeability. Oil recovery from water imbibition tests from such at tight rock can be as high as 25 percent. Chapter II discusses solution gas-drive for cold production from heavy-oil reservoirs. The impetus for this work is the study of new gas phase formation from in-situ process which can be significantly

  16. Fiat and bona fide boundaries

    OpenAIRE

    Smith, B.; Varzi, A.

    1997-01-01

    Consider John, the moon, a lump of cheese. These are objects possessed of divisible bulk. They can be divided, in reality or in thought, into spatially extended parts. They have interiors. They also have boundaries, which we can think of (roughly) asinfinitely thin extremal slices. The boundary of the moon is its surface. The boundary of John is the surface of his skin. But what of inner boundaries, the boundaries of the interior parts of things? There are many genuine two-dimensional (sphere...

  17. Pediatric elbow fractures: MRI evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Beltran, J. (Dept. of Radiology, Hospital for Joint Diseases, New York, NY (United States)); Rosenberg, Z.S. (Dept. of Radiology, Hospital for Joint Diseases, New York, NY (United States)); Kawelblum, M. (Dept. of Orthopaedic Surgery, Hospital for Joint Diseases, New York, NY (United States)); Montes, L. (Dept. of Radiology, Beth Israel Medical Center, New York, NY (United States)); Bergman, A.G. (Dept. of Radiology, Stanford Univ., School of Medicine, CA (United States)); Strongwater, A. (Dept. of Orthopaedic Surgery, Hospital for Joint Diseases, New York, NY (United States))

    1994-05-01

    Magnetic resonance imaging (MRI) was performed in eight patients under the age of 8 years who suffered elbow fractures, to assess possible fracture extension into the distal nonossified epiphysis of the humerus in seven cases and to determine the displacement and location of the radial head in one case. MRI allowed accurate depiction of the fracture line when it extended into the cartilaginous epiphysis. In four cases, MRI findings were confirmed at surgery. In five cases, surgery was obviated because no articular extension of the fracture was seen on MRI (4 cases) or because no displacement was noted (1 case). In one patient, the plain film diagnosis of a Salter type II fracture was changed to Salter type IV on the basis of the MRI findings. It is concluded that MRI might play a role in the preoperative evaluation of pediatric patients presenting with elbow trauma when extension of the fracture cannot be determined with routine radiographic studies. (orig.)

  18. Complex Fluids and Hydraulic Fracturing.

    Science.gov (United States)

    Barbati, Alexander C; Desroches, Jean; Robisson, Agathe; McKinley, Gareth H

    2016-06-07

    Nearly 70 years old, hydraulic fracturing is a core technique for stimulating hydrocarbon production in a majority of oil and gas reservoirs. Complex fluids are implemented in nearly every step of the fracturing process, most significantly to generate and sustain fractures and transport and distribute proppant particles during and following fluid injection. An extremely wide range of complex fluids are used: naturally occurring polysaccharide and synthetic polymer solutions, aqueous physical and chemical gels, organic gels, micellar surfactant solutions, emulsions, and foams. These fluids are loaded over a wide range of concentrations with particles of varying sizes and aspect ratios and are subjected to extreme mechanical and environmental conditions. We describe the settings of hydraulic fracturing (framed by geology), fracturing mechanics and physics, and the critical role that non-Newtonian fluid dynamics and complex fluids play in the hydraulic fracturing process.

  19. [Patella fractures in knee arthroplasty].

    Science.gov (United States)

    Roth, A; Ghanem, M; Fakler, J

    2016-05-01

    Periprosthetic patella fractures occur both with and without retropatellar joint replacement. A non-operative treatment yields satisfactory results with low morbidity. It can be applied in minimally displaced fractures that have an intact retropatellar component and an intact extensor mechanism, combined with an initial immobilization. The surgical treatment is associated with relatively poor results and with high complication rates. There was only minor improvement of functional results, no matter which surgical technique was used. Surgical intervention is still required in fractures with a loosening of the patellar component, considerable dislocations of fragments, and damage to or rupture of the extensor mechanism. In particular, type II fractures require repair of the extensor mechanism and the fracture or patellectomy. Type III fractures require a revision or resection of the patella, a patelloplasty or total patellectomy. In addition, early or late reconstruction using allograft to restore the extensor mechanism can be taken in consideration.

  20. [Distal humerus fractures in children].

    Science.gov (United States)

    Schneidmueller, D; Boettger, M; Laurer, H; Gutsfeld, P; Bühren, V

    2013-11-01

    Fractures of the distal humerus belong to the most common injuries of the upper arm in childhood. Most frequently occurring is the supracondylar fracture of the distal humerus. In these cases and in the second most common epicondylar fractures, the metaphysis is affected and these fractures are therefore extra-articular. They have to be distinguished from articular fractures regarding therapy and prognosis. The growth potential of the distal epiphysis is very limited as is the possibility of spontaneous correction so that major dislocations should not be left uncorrected. Unstable and especially dislocated articular fractures must be anatomically reconstructed employing various osteosynthetic techniques, mostly combined with immobilization. Insufficient reconstruction, growth disturbance and non-union can result in axial deformities, such as cubitus valgus and varus, restriction of motion, pain and nerve palsy.

  1. Periprosthetic fractures of the acetabulum.

    Science.gov (United States)

    Helfet, David L; Ali, Arif

    2004-01-01

    Periprosthetic fractures of the acetabulum after total hip arthroplasty are uncommon, but are increasing in number and severity. These fractures may occur intraoperatively, during the perioperative period, or many years after the total hip arthroplasty. Periprosthetic fractures of the acetabulum vary in severity and may involve stress fractures of the pubis or medial wall, significant bone loss secondary to osteolysis and subsequent loss of column integrity, or complete pelvic discontinuity. Treatment differs depending on the complexity of the fracture and the stability of the acetabular prosthesis. Surgical treatment for an unstable acetabulum should stabilize the bony columns of the acetabulum, provide bone grafting of defects, and should maintain adequate bone stock for replacement of a stable acetabular implant. Strict adherence to the principles of fracture surgery is required to achieve bony union of the acetabular columns and provide a stable environment for reimplantation of an acetabular component.

  2. Seismic determination of saturation in fractured reservoirs

    Science.gov (United States)

    Brown, R.L.; Wiggins, M.L.; Gupta, A.

    2002-01-01

    Detecting the saturation of a fractured reservoir using shear waves is possible when the fractures have a geometry that induces a component of movement perpendicular to the fractures. When such geometry is present, vertically traveling shear waves can be used to examine the saturation of the fractured reservoir. Tilted, corrugated, and saw-tooth fracture models are potential examples.

  3. Modeling elastic tensile fractures in snow using nonlocal damage mechanics

    Science.gov (United States)

    Borstad, C. P.; McClung, D. M.

    2011-12-01

    The initiation and propagation of tensile fractures in snow and ice are fundamental to numerous important physical processes in the cryosphere, from iceberg calving to ice shelf rift propagation to slab avalanche release. The heterogeneous nature of snow and ice, their proximity to the melting temperature, and the varied governing timescales typically lead to nonlinear fracture behavior which does not follow the predictions of Linear Elastic Fracture Mechanics (LEFM). Furthermore, traditional fracture mechanics is formally inapplicable for predicting crack initiation in the absence of a pre-existing flaw or stress concentration. An alternative to fracture mechanics is continuum damage mechanics, which accounts for the material degradation associated with cracking in a numerically efficient framework. However, damage models which are formulated locally (e.g. stress and strain are defined as point properties) suffer from mesh-sensitive crack trajectories, spurious localization of damage and improper fracture energy dissipation with mesh refinement. Nonlocal formulations of damage, which smear the effects of the material heterogeneity over an intrinsic length scale related to the material microstructure, overcome these difficulties and lead to numerically efficient and mesh-objective simulations of the tensile failure of heterogeneous materials. We present the results of numerical simulations of tensile fracture initiation and propagation in cohesive snow using a nonlocal damage model. Seventeen beam bending experiments, both notched and unnotched, were conducted using blocks of cohesive dry snow extracted from an alpine snowpack. Material properties and fracture parameters were calculated from the experimental data using beam theory and quasi-brittle fracture mechanics. Using these parameters, a nonlocal isotropic damage model was applied to two-dimensional finite element meshes of the same scale as the experiments. The model was capable of simulating the propagation

  4. Fracture and Healing of Rock Salt Related to Salt Caverns

    Energy Technology Data Exchange (ETDEWEB)

    Chan, K.S.; Fossum, A.F.; Munson, D.E.

    1999-03-01

    In recent years, serious investigations of potential extension of the useful life of older caverns or of the use of abandoned caverns for waste disposal have been of interest to the technical community. All of the potential applications depend upon understanding the reamer in which older caverns and sealing systems can fail. Such an understanding will require a more detailed knowledge of the fracture of salt than has been necessary to date. Fortunately, the knowledge of the fracture and healing of salt has made significant advances in the last decade, and is in a position to yield meaningful insights to older cavern behavior. In particular, micromechanical mechanisms of fracture and the concept of a fracture mechanism map have been essential guides, as has the utilization of continuum damage mechanics. The Multimechanism Deformation Coupled Fracture (MDCF) model, which is summarized extensively in this work was developed specifically to treat both the creep and fracture of salt, and was later extended to incorporate the fracture healing process known to occur in rock salt. Fracture in salt is based on the formation and evolution of microfractures, which may take the form of wing tip cracks, either in the body or the boundary of the grain. This type of crack deforms under shear to produce a strain, and furthermore, the opening of the wing cracks produce volume strain or dilatancy. In the presence of a confining pressure, microcrack formation may be suppressed, as is often the case for triaxial compression tests or natural underground stress situations. However, if the confining pressure is insufficient to suppress fracture, then the fractures will evolve with time to give the characteristic tertiary creep response. Two first order kinetics processes, closure of cracks and healing of cracks, control the healing process. Significantly, volume strain produced by microfractures may lead to changes in the permeability of the salt, which can become a major concern in

  5. Multiple-point statistical prediction on fracture networks at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Liu, X.Y; Zhang, C.Y.; Liu, Q.S.; Birkholzer, J.T.

    2009-05-01

    In many underground nuclear waste repository systems, such as at Yucca Mountain, water flow rate and amount of water seepage into the waste emplacement drifts are mainly determined by hydrological properties of fracture network in the surrounding rock mass. Natural fracture network system is not easy to describe, especially with respect to its connectivity which is critically important for simulating the water flow field. In this paper, we introduced a new method for fracture network description and prediction, termed multi-point-statistics (MPS). The process of the MPS method is to record multiple-point statistics concerning the connectivity patterns of a fracture network from a known fracture map, and to reproduce multiple-scale training fracture patterns in a stochastic manner, implicitly and directly. It is applied to fracture data to study flow field behavior at the Yucca Mountain waste repository system. First, the MPS method is used to create a fracture network with an original fracture training image from Yucca Mountain dataset. After we adopt a harmonic and arithmetic average method to upscale the permeability to a coarse grid, THM simulation is carried out to study near-field water flow in the surrounding waste emplacement drifts. Our study shows that connectivity or patterns of fracture networks can be grasped and reconstructed by MPS methods. In theory, it will lead to better prediction of fracture system characteristics and flow behavior. Meanwhile, we can obtain variance from flow field, which gives us a way to quantify model uncertainty even in complicated coupled THM simulations. It indicates that MPS can potentially characterize and reconstruct natural fracture networks in a fractured rock mass with advantages of quantifying connectivity of fracture system and its simulation uncertainty simultaneously.

  6. FUNCTIONAL OUTCOME OF SURGICAL MANAGEMENT OF ACETABULAR FRACTURES BY INTERNAL FIXATION

    Directory of Open Access Journals (Sweden)

    Sagar

    2015-06-01

    Full Text Available BACKGROUND: The treatment of acetabular fractures has seen major advances in the field of orthopaedic traumatology. Conservative treatment of acetabular fractures leads to poor results. Newer diagnostic tools like the Computed Tomography (CT scan help in analyzing the three dimensional disturbance in the normal anatomy and plan the surgical management accordingly. In recent years operative treatment has become the treat ment of choice in the management of acetabular fractures as precise anatomical reduction with adequate internal fixation can be attained. OBJECTIVES : To evaluate the functional outcome of operatively managed acetabular fractures , and assess the efficacy of operative fixation of acetabular fractures , and also study the complications of operative fixation of acetabular fractures. MATERIALS AND METHODS: Fifty five patients (49 male & six female admitted to Sanjay Gandhi Institute of Trauma and Orthopaedics wi th acetabular fractures underwent open reduction and internal fixation. All patients were evaluated with Matta et al score with a minimum of follow up of six months. RESULTS: There were 24 (43.6% patients with bicolumnar fractures , 15(27.3% had posterior column fractures , 10(18.1% had posterior wall fractures , five (9.1% had transverse fractures , and one (1.8% patient had an anterior column fracture. Full weight bearing was attained in thirty five (63.6% patients in 16 weeks and in twenty (36.4% pati ents after 16 weeks. Forty five (81.8% patients were free of complications. According to Matta et al score 27(49.1% had excellent , 15(27.3% had good , nine (16.4% had fair , and four (7.3% had poor results. CONCLUSION: Open reduction and internal fixati on of acetabular fractures is a reliable technique , minimizes healing time and provides congruent joint reduction. Operative treatment of acetabular fractures results in predictable union and good clinical results with a low rate of complications.

  7. Multiple-point statistical prediction on fracture networks at Yucca Mountain

    Science.gov (United States)

    Liu, Xiaoyan; Zhang, Chengyuan; Liu, Quansheng; Birkholzer, Jens

    2009-05-01

    In many underground nuclear waste repository systems, such as Yucca Mountain project, water flow rate and amount of water seepage into the waste emplacement drifts are mainly determined by hydrological properties of fracture network in the surrounding rock mass. Natural fracture network system is not easy to describe, especially with respect to its connectivity which is critically important for simulating the water flow field. In this paper, we introduced a new method for fracture network description and prediction, termed multi-point-statistics (MPS). The process of Multi-point Statistical method is to record multiple-point statistics concerning the connectivity patterns of fracture network from a known fracture map, and to reproduce multiple-scale training fracture patterns in a stochastic manner, implicitly and directly. It is applied to fracture data to study flow field behavior at Yucca Mountain waste repository system. First, MPS method is used to create fracture network with original fracture training image from Yucca Mountain dataset. After we adopt a harmonic and arithmetic average method to upscale the permeability to a coarse grid, THM simulation is carried out to study near-field water flow in surrounding rock of waste emplacement drifts. Our study shows that connectivity or pattern of fracture network can be grasped and reconstructed by Multi-Point-Statistical method. In theory, it will lead to better prediction of fracture system characteristics and flow behavior. Meanwhile, we can obtain variance from flow field, which gives us a way to quantify uncertainty of models even in complicated coupled THM simulation. It indicates that Multi-Point Statistics is a potential method to characterize and reconstruct natural fracture network in a fractured rock mass with advantages of quantifying connectivity of fracture system and its simulation uncertainty simultaneously.

  8. Remote intracranial hemorrhage following surgery for giant orbitofrontal growing skull fracture: A lesson learnt

    Directory of Open Access Journals (Sweden)

    Sachin Baldawa

    2016-01-01

    Full Text Available Growing skull fracture is an extremely rare complication of pediatric head injury, especially in infants. Repair of the dural tear early in the course of development of growing skull fracture has been suggested for a better outcome. Surgical repair of large, tense growing skull fractures, especially those in the communication of the ventricles can lead to potentially life-threatening complications. The author reports a rare case of remote intracranial hemorrhage following surgery for large, tense growing skull fracture in a 12-year-old girl and discusses the likely pathogenesis and possible ways to avoid this life-threatening complication.

  9. Bone loss and fractures in multiple sclerosis: focus on epidemiologic and physiopathological features

    Directory of Open Access Journals (Sweden)

    Dionyssiotis Y

    2011-07-01

    Full Text Available Yannis DionyssiotisRehabilitation Department, Physical and Social Rehabilitation Center, Amyntæo, Florina, GreeceAbstract: Multiple sclerosis (MS affects the central nervous system leading to disability and is complicated by bone loss and fractures. Despite the acceptance of osteoporosis and fractures as two major public health problems, in people with MS the mechanisms have not been investigated adequately. Physicians and patients usually focus on the major cause of disability and neglect the multiple risk factors for osteoporosis and fractures in this specific population. This review updates the epidemiology and physiopathological mechanisms in MS.Keywords: multiple sclerosis, bone, fractures, osteoporosis, osteopenia

  10. [Minimal invasive treatment of massively dislocated radial neck fractures in children by percutaneous joystick reposition and Prevot nailing].

    Science.gov (United States)

    Hilgert, R E; Dallek, M; Rueger, J M

    2002-02-01

    Undisplaced fractures of the proximal radius can generally be treated conservatively with good results. In children, spontaneous correction of some angular deformities can be expected during growth. Nevertheless, more severely displaced fracture types may require reduction in children, too. Open reduction and internal fracture fixation have shown to lead to a loss in range of motion frequently. A technique of percutaneous fracture reduction is demonstrated that can provide good results in cases when closed techniques have failed. A Kirschner wire is used to manipulate the fracture fragments percutaneously, which can often prevent open techniques. An additionally performed elastic-stable intramedullary nailing can add to an effective stabilisation and encourage to early physiotherapy.

  11. CT examinations of healing fractures

    Energy Technology Data Exchange (ETDEWEB)

    Nutz, V.; Uexkuell-Gueldenband, V. v.

    1988-10-01

    The CT appearances of healing fractures were studied following tibial osteotomy in a dog. Traditional radiological investigations and CT were carried out until healing was complete; CT showed callus on the ninth day, whereas radiographs only showed it after 19 days. After 32 days, callus filled nearly the entire medullary cavity. Similar observations were made in several human situations. CT demonstrates interposed material in the fracture very clearly, even if there is marked callus formation within the fracture.

  12. Numerical Investigation of Influence of In-Situ Stress Ratio, Injection Rate and Fluid Viscosity on Hydraulic Fracture Propagation Using a Distinct Element Approach

    Directory of Open Access Journals (Sweden)

    Bo Zhang

    2016-02-01

    Full Text Available Numerical simulation is very useful for understanding the hydraulic fracturing mechanism. In this paper, we simulate the hydraulic fracturing using the distinct element approach, to investigate the effect of some critical parameters on hydraulic fracturing characteristics. The breakdown pressure obtained by the distinct element approach is consistent with the analytical solution. This indicates that the distinct element approach is feasible on modeling the hydraulic fracturing. We independently examine the influence of in-situ stress ratio, injection rate and fluid viscosity on hydraulic fracturing. We further emphasize the relationship between these three factors and their contributions to the hydraulic fracturing. With the increase of stress ratio, the fracture aperture increases almost linearly; with the increase of injection rate and fluid viscosity, the fracture aperture and breakdown pressure increase obviously. A low value of product of injection rate and fluid viscosity (i.e., Qμ will lead to narrow fracture aperture, low breakdown pressure, and complex or dispersional hydraulic fractures. A high value of Qμ would lead wide fracture aperture, high breakdown pressure, and simple hydraulic fractures (e.g., straight or wing shape. With low viscosity fluid, the hydraulic fracture geometry is not sensitive to stress ratio, and thus becomes a complex fracture network.

  13. Chemical and Mechanical Alteration of Fractures: Micro-Scale Simulations and Comparison to Experimental Results

    Science.gov (United States)

    Ameli, P.; Detwiler, R. L.; Elkhoury, J. E.; Morris, J. P.

    2012-12-01

    Fractures are often the main pathways for subsurface fluid flow especially in rocks with low matrix porosity. Therefore, the hydro-mechanical properties of fractures are of fundamental concern for subsurface CO2 sequestration, enhanced geothermal energy production, enhanced oil recovery, and nuclear waste disposal. Chemical and mechanical stresses induced during these applications may lead to significant alteration of the hydro-mechanical properties of fractures. Laboratory experiments aimed at understanding the chemo-hydro-mechanical response of fractures have shown a range of results that contradict simple conceptual models. For example, under conditions favoring mineral dissolution, where one would expect an overall increase in permeability and fracture aperture, permeability increases under some conditions and decreases under others. Recent experiments have attempted to link these core-scale observations to the relevant small-scale processes occurring within fractures. Results suggest that the loss of mechanical strength in asperities due to chemical alteration may cause non-uniform deformation and alteration of fracture apertures. However, it remains difficult to directly measure the coupled chemical and mechanical processes that lead to alteration of contacting fracture surfaces, which challenges our ability to predict the long-term evolution of the hydro-mechanical properties of fractures. Here, we present a computational model that uses micro-scale surface roughness and explicitly couples dissolution and elastic deformation to calculate local alterations in fracture aperture under chemical and mechanical stresses. Chemical alteration of the fracture surfaces is modeled using a depth-averaged algorithm of fracture flow and reactive transport. Then, we deform the resulting altered fracture-surfaces using an algorithm that calculates the elastic deformation. Nonuniform dissolution may cause the location of the resultant force between the two contacting

  14. Functional validation of putative toxin-antitoxin genes from the Gram-positive pathogen Streptococcus pneumoniae: phd-doc is the fourth bona-fide operon

    Directory of Open Access Journals (Sweden)

    Wai Ting eChan

    2014-12-01

    Full Text Available Bacterial toxin-antitoxin (TAs loci usually consist of two genes organized as an operon, where their products are bound together and inert under normal conditions. However, under stressful circumstances the antitoxin, which is more labile, will be degraded more rapidly, thereby unleashing its cognate toxin to act on the cell. This, in turn, causes cell stasis or cell death, depending on the type of TAs and/or time of toxin exposure. Previously based on in silico analyses, we proposed that Streptococcus pneumoniae, a pathogenic Gram-positive bacterium, may harbor between four to ten putative TA loci depending on the strains. Here we have chosen the pneumococcal strain Hungary19A-6 which contains all possible ten TA loci. In addition to the three well-characterized operons, namely relBE2, yefM-yoeB, and pezAT, we show here the functionality of a fourth operon that encodes the pneumococcal equivalent of the phd-doc TA. Transcriptional fusions with gene encoding Green Fluorescent Protein showed that the promoter was slightly repressed by the Phd antitoxin, and exhibited almost background values when both Phd-Doc were expressed together. These findings demonstrate that phd-doc shows the negative self-regulatory features typical for an authentic TA. Further, we also show that the previously proposed TAs XreA-Ant and Bro-XreB, although they exhibit a genetic organization resembling those of typical TAs, did not appear to confer a functional behavior corresponding to bona fide TAs. In addition, we have also discovered new interesting bioinformatics results for the known pneumococcal TAs RelBE2 and PezAT. A global analysis of the four identified toxins-antitoxins in the pneumococcal genomes (PezAT, RelBE2, YefM-YoeB, and Phd-Doc showed that RelBE2 and Phd-Doc are the most conserved ones. Further, there was good correlation among TA types, clonal complexes and sequence types in the 48 pneumococcal strains analyzed.

  15. Three-phase flow simulations in discrete fracture networks

    Science.gov (United States)

    Geiger, S.; Niessner, J.; Matthai, S. K.; Helmig, R.

    2006-12-01

    Fractures are often the key conduits for fluid flow in otherwise low permeability rocks. Their presence in hydrocarbon reservoirs leads to complex production histories, unpredictable coupling of wells, rapidly changing flow rates, possibly early water breakthrough, and low final recovery. Recently, it has been demonstrated that a combination of finite volume and finite element discretization is well suited to model incompressible, immiscible two-phase flow in 3D discrete fracture networks (DFN) representing complexly fractured rocks. Such an approach has been commercialized in Golder Associates' FracMan Reservoir Edition software. For realistic reservoir simulations, however, it would be desirable if a third compressible gas phase can be included which is often present at reservoir conditions. Here we present the extension of an existing node-centred finite volume - finite element (FEFV) discretization for the efficient and accurate simulations of three-component - three-phase flow in geologically realistic representations of fractured porous media. Two possible types of fracture networks can be used: In 2D, they are detailed geometrical representations of fractured rock masses mapped in field studies. In 3D, they are geologically constrained, stochastically generated discrete fracture networks. Flow and transport can be simulated for fractures only or for fractures and matrix combined. The governing equations are solved decoupled using an implicit-pressure, explicit-saturation (IMPES) approach. Flux and concentration terms can be treated with higher-order accuracy in the finite volume scheme to preserve shock fronts. The method is locally mass conservative and works on unstructured, spatially refined grids. Flash calculations are carried out by a new description of the Black-Oil model. Capillary and gravity effects are included in this formulation. The robustness and accuracy of this formulation is shown in several applications. First, grid convergence is

  16. Fracture Phenomena in Amorphous Selenium

    DEFF Research Database (Denmark)

    Lindegaard-Andersen, Asger; Dahle, Birgit

    1966-01-01

    the velocities of ultrasonic longitudinal and shear waves were measured to 1820 m/sec and 930 m/sec, respectively. Based on these results the two line systems in the transition zone can be interpreted as ``Wallner lines'' with sources within the zone. ©1966 The American Institute of Physics......Fracture surfaces of amorphous selenium broken in flexure at room temperature have been studied. The fracture velocity was found to vary in different regions of the fracture surface. Peculiar features were observed in a transition zone between fast and slower fracture. In this zone cleavage steps...

  17. Posterior bicondylar tibial plateau fractures.

    Science.gov (United States)

    Carlson, DuWayne A

    2005-02-01

    To present a case series of patients with posterior bicondylar tibial plateau fractures treated by direct fracture exposure and fixation through dual incisions. Retrospective clinical study. Level 1 trauma centers. Eight patients were identified that had posterior bicondylar tibial plateau fractures. Two patients had depressed posterolateral tibial plateau fractures with contained defects and did not have direct fracture exposure. One patient died of medical problems leaving 5 patients who underwent direct fracture exposure, reduction, and fixation. Posteromedial followed by posterolateral open reduction and internal fixation of posterior bicondylar tibial plateau fractures. At 6 to 24 months follow-up (mean 13 months), all patients returned to near full activities, each with aching after prolonged standing (8-hour shift). Range of motion averaged 2 degrees to 121 degrees of flexion. Three of 5 returned to manual labor jobs; the others were not employed at the time of injury. Posterior bicondylar tibial plateau fractures have a high association with lateral meniscal pathology and can be associated with anterior cruciate ligament injury. Reduction of the posterior plateau condyles is easiest with the knee in full extension. Flexion contractures can be a problem, and patients should be encouraged to regain/maintain knee extension. The dual-incision approach to these challenging fractures can result in good to excellent knee function for these patients.

  18. Postpartal sacral fracture without osteoporosis.

    Science.gov (United States)

    Rousière, M; Kahan, A; Job-Deslandre, C

    2001-02-01

    Stress fractures of the sacrum during pregnancy or the postpartum seem uncommon. We report a new case of nontrauma-related postpartal sacral fracture. Only four similar cases have been reported to date. The patient was 36 years of age and her fracture was diagnosed four weeks after her first delivery. Vitamin D levels were low, but there was no osteomalacia. Other standard laboratory tests were normal, as were absorptiometry measurements at the lumbar spine and femur. Rheumatologists should consider sacral fracture in pregnant or nursing patients with buttock pain. Magnetic resonance imaging is the diagnostic investigation of choice.

  19. Classification of subtrochanteric femoral fractures.

    Science.gov (United States)

    Loizou, C L; McNamara, I; Ahmed, K; Pryor, G A; Parker, M J

    2010-07-01

    A review of the literature identified 15 different classification methods for subtrochanteric femoral fractures. Only eight of those classifications defined the area of bone, which constituted a subtrochanteric fracture. The actual length of femur defined as the subtrochanteric zone varied from 3 cm up to the level of the femoral isthmus. There was no agreement between the different classifications regarding the proximal and distal border or for those fractures, which traverse anatomical boundaries. In the various classifications, fractures were subdivided into 2-15 subgroups. The majority of the identified studies were unable to find the classifications useful in either determining treatment or predicting the outcome after treatment. We subdivided subtrochanteric fractures into three types based on the degree of fracture comminution. We examined the inter- and intra-observer agreement of our recommended classification. One orthopaedic consultant, one specialist hip fracture surgeon, two trainee registrar orthopaedic surgeons and one specialty trainee in orthopaedics, on two different occasions, 8 weeks apart, independently classified the radiographs of 20 patients with a subtrochanteric fracture. The mean kappa value for inter- and intra-observer variation was 0.71 and 0.79, respectively, with both showing substantial agreement and, therefore, this simpler classification is recommended. Based on the review of previous classification methods, we also recommend that the subtrochanteric zone be defined as the one in which the fracture line crossing the femur is predominantly within the area of bone extending 5 cm below the lower border of the lesser trochanter.

  20. Managing periprosthetic femoral stem fractures.

    Science.gov (United States)

    Rosenberg, Aaron G

    2006-06-01

    Periprosthetic fractures can be difficult to manage. The classification system developed in Vancouver is simple and useful in determining appropriate treatment. It takes into account the site of the fracture, the stability of the implant, and the surrounding bone stock, which are the important elements of the fracture and hip that determines treatment. Understanding this classification system should allow the practitioner to choose the appropriate treatment. In addition to fracture management skills, understanding how to perform a host of hip revision technique may also be required.

  1. Bilateral Mandibular Condylar Fractures with Associated External Auditory Canal Fractures and Otorrhagia

    OpenAIRE

    Dang, David

    2016-01-01

    A rare case of bilateral mandibular condylar fractures associated with bilateral external auditory canal fractures and otorrhagia is reported. The more severe external auditory canal fracture was present on the side of high condylar fracture, and the less severe external auditory canal fracture was ipsilateral to the condylar neck fracture. A mechanism of injury is proposed to account for such findings.

  2. Bilateral Mandibular Condylar Fractures with Associated External Auditory Canal Fractures and Otorrhagia.

    Science.gov (United States)

    Dang, David

    2007-01-01

    A rare case of bilateral mandibular condylar fractures associated with bilateral external auditory canal fractures and otorrhagia is reported. The more severe external auditory canal fracture was present on the side of high condylar fracture, and the less severe external auditory canal fracture was ipsilateral to the condylar neck fracture. A mechanism of injury is proposed to account for such findings.

  3. Fracture network growth for prediction of fracture characteristics and connectivity in tight reservoir rocks

    NARCIS (Netherlands)

    Barnhoorn, A.; Cox, S.F.

    2012-01-01

    Fracturing experiments on very low-porosity dolomite rocks shows a difference in growth of fracture networks by stress-driven fracturing and fluid-driven fracturing. Stress-driven fracture growth, in the absence of fluid pressure, initially forms fractures randomly throughout the rocks followed by g

  4. Inflammatory markers and risk of hip fracture in older white women: the study of osteoporotic fractures.

    Science.gov (United States)

    Barbour, Kamil E; Lui, Li-Yung; Ensrud, Kristine E; Hillier, Teresa A; LeBlanc, Erin S; Ing, Steven W; Hochberg, Marc C; Cauley, Jane A

    2014-09-01

    Hip fractures are the most devastating consequence of osteoporosis and impact 1 in 6 white women leading to a two- to threefold increased mortality risk in the first year. Despite evidence of inflammatory markers in the pathogenesis of osteoporosis, few studies have examined their effect on hip fracture. To determine if high levels of inflammation increase hip fracture risk and to explore mediation pathways, a case-cohort design nested in a cohort of 4709 white women from the Study of Osteoporotic Fractures was used. A random sample of 1171 women was selected as the subcohort (mean age 80.1 ± 4.2 years) plus the first 300 women with incident hip fracture. Inflammatory markers interleukin-6 (IL-6) and soluble receptors (SR) for IL-6 (IL-6 SR) and tumor necrosis factor (TNF SR1 and TNF SR2) were measured, and participants were followed for a median (interquartile range) of 6.3 (3.7, 6.9) years. In multivariable models, the hazard ratio (HR) of hip fracture for women in the highest inflammatory marker level (quartile 4) was 1.64 (95% confidence interval [CI], 1.09-2.48, p trend = 0.03) for IL-6 and 2.05 (95% CI, 1.35-3.12, p trend hip fracture was 1.51 (95% CI, 1.07-2.14) and 1.42 (95% CI, 0.87-2.31) compared with women with zero to one marker(s) in the highest quartile (p trend = 0.03). After individually adjusting for seven potential mediators, cystatin-C (a biomarker of renal function) and bone mineral density (BMD) attenuated HRs among women with the highest inflammatory burden by 64% and 50%, respectively, suggesting a potential mediating role. Older white women with high inflammatory burden are at increased risk of hip fracture in part due to poor renal function and low BMD. © 2014 American Society for Bone and Mineral Research.

  5. Extreme Rainfall Impacts in Fractured Permeable Catchments

    Science.gov (United States)

    Ireson, A. M.; Butler, A. P.

    2009-12-01

    Serious groundwater flooding events have occurred on Chalk catchments in both the UK and north west Europe in the last decade, causing substantial amounts of disruption and economic damage. These fractured, permeable catchments are characterized by low surface runoff, high baseflow indices and strongly attenuated streamflow hydrographs. They have a general resilience to drought and pluvial/fluvial flooding. The small pore size of the Chalk matrix (~ 1 µm) exerts a high suction, such that dynamic storage is primarily due to the fractures, and amounts to ~ 1% of the total volume. As a result, under sustained rainfall the water table can rise up to exceptional levels leading to surface water emergence from springs and valleys. Floodwater may slowly drain with the topography, or, in localized depressions, it may simply pond until the groundwater levels decline. In winter 2000/1, a sequence of individually unexceptional rainfall events over several months led to large scale flooding in the Pang catchment, Berkshire, UK. By contrast, an extreme rainfall event on 20th July 2007 in the same catchment caused a very rapid response at the water table, but due to the antecedent conditions did not lead to flooding. The objective of this study is to quantify how the water table in a fractured permeable catchment responds to different types of rainfall, and the implications of this for groundwater flooding. We make use of measurements from the Pang catchment, including: rainfall (tipping bucket gauges); actual evaporation (eddy flux correlation); soil water content (profile probes and neutron probes); near surface matric potential (tensiometers and equitensiometers); deep (>10m) matric potential (deep jacking tensiometers); and water table elevation (piezometers). Conventional treatment of recharge in Chalk aquifers considers a fixed bypass component of rainfall, normally 15%, to account for the role of the fractures. However, interpretation of the field data suggest three modes

  6. A PROSPECTIVE STUDY OF SURGICAL MANAGEMENT OF UNSTABLE MALLEOLAR FRACTURES IN ADULTS

    Directory of Open Access Journals (Sweden)

    Chandra Sekharam Naidu

    2015-10-01

    Full Text Available M alleolar fractures are one of the most common lower extremity fractures in orthopaedic traumatology. Ankle injuries gain importance because body weight is transmitted through it and locomotion depends upon the stability of this joint. Malleolar fractures have varied presentations which have given rise to a wide variety of classification systems, of which two are in vogue Lauge - Hansens and Danis - Weber classification. As with all intra articular fractures, malleolar fractu res necessitate accurate reduction and stable internal fixation. When malleolar fractures are not reduced accurately they may lead to post traumatic painful restriction of motion or osteoarthritis or both . 1 Many of the fractures which are stable are treate d by conservative treatment and have given good result. The other unstable, displaced and open fractures require open reduction internal fixation. The superiority of ORIF over closed treatment have been thoroughly demonstrated in literature . 2 The purpose o f this study is to assess the functional outcome and results of surgical treatment of malleolar fractures. The treatment options with ORIF technique available for malleolar fractures, to attain a proper anatomical alignment and stability of the ankle joint , can lead to rewarding outcome for the patient and surgeon

  7. Generalized linear sampling method for elastic-wave sensing of heterogeneous fractures

    CERN Document Server

    Pourahmadian, Fatemeh; Haddar, Houssem

    2016-01-01

    A theoretical foundation is developed for active seismic reconstruction of fractures endowed with spatially-varying interfacial condition (e.g.~partially-closed fractures, hydraulic fractures). The proposed indicator functional carries a superior localization property with no significant sensitivity to the fracture's contact condition, measurement errors, and illumination frequency. This is accomplished through the paradigm of the $F_\\sharp$-factorization technique and the recently developed Generalized Linear Sampling Method (GLSM) applied to elastodynamics. The direct scattering problem is formulated in the frequency domain where the fracture surface is illuminated by a set of incident plane waves, while monitoring the induced scattered field in the form of (elastic) far-field patterns. The analysis of the well-posedness of the forward problem leads to an admissibility condition on the fracture's (linearized) contact parameters. This in turn contributes toward establishing the applicability of the $F_\\sharp...

  8. EFFECTS OF STATIC ELECTRIC FIELD ON THE FRACTURE BEHAVIOR OF PIEZOELECTRIC CERAMICS

    Institute of Scientific and Technical Information of China (English)

    Tong-Yi Zhang

    2002-01-01

    The paper gives an overview on experimental observations of thefailure behavior of electrically insulating and conducting cracks in piezoelectric ce-ramics. The experiments include the indentation fracture test, the bending test onsmooth samples, and the fracture test on pre-notched (or pre-cracked) compact ten-sion samples. For electrically insulating cracks, the experimental results show a com-plicated fracture behavior under electrical and mechanical loading. Fracture dataare much scattered when a static electric field is applied. A statistically based frac-ture criterion is required. For electrically conducting cracks, the experimental resultsdemonstrate that static electric fields can fracture poled and depoled lead zirconatetitanate ceramics and that the concepts of fracture mechanics can be used to mea-sure the electrical fracture toughness. Furthermore, the electrical fracture toughnessis much higher than the mechanical fracture toughness. The highly electrical fracturetoughness arises from the greater energy dissipation around the conductive crack tipunder purely electric loading, which is impossible under mechanical loading in thebrittle ceramics.

  9. Fracture Rates and Fracture Sites in Patients With Osteogenesis Imperfecta

    DEFF Research Database (Denmark)

    Folkestad, Lars; Hald, Jannie Dahl; Ersbøll, Annette Kjaer;

    2016-01-01

    , with a peak during the toddler and adolescent years (incidence rate [IR] 233.9 per 1000 person years), fewer fractures during adulthood (IR 84.5 per 1000 person years), and increased fracture rates in older women (IR 111.9 per 1000 person years). This is the largest register-based nationwide study...... years. In comparison, 709 persons in the reference population experienced a total of 1018 fractures during follow-up. Both male and female patients with OI had an increased fracture rate throughout their life. The fracture rate ratio for participants aged 0 to 19 years was 10.7, for participants aged 20...... to 54 years 17.2, and for participants aged 55 years and over 4.1 when compared to the reference population. The highest fracture rate was seen in males with OI aged 0 to 19 years (257 fractures per 1000 person-years). The fractures appear to follow the same pattern as in the general population...

  10. Similar Fracture Patterns in Human Nose and Gothic Cathedral.

    Science.gov (United States)

    Lee, Shu Jin; Tse, Kwong Ming; Lee, Heow Pueh

    2015-10-01

    This study proposes that the bony anatomy of the human nose and masonry structure of the Gothic cathedral are geometrically similar, and have common fracture patterns. We also aim to correlate the fracture patterns observed in patients' midface structures with those seen in the Gothic cathedral using computational approach. CT scans of 33 patients with facial fractures were examined and compared with computer simulations of both the Gothic cathedral and human nose. Three similar patterns were found: (1) Cracks of the nasal arch with crumpling of the vertical buttresses akin to the damage seen during minor earthquakes; (2) lateral deviation of the central nasal arch and collapse of the vertical buttresses akin to those due to lateral forces from wind and in major earthquakes; and (3) Central arch collapse seen as a result of collapse under excessive dead weight. Interestingly, the finding of occult nasal and septal fractures in the mandible fractures with absence of direct nasal trauma highlights the possibility of transmission of forces from the foundation to the arch leading to structural failure. It was also found that the structural buttresses of the Gothic cathedral delineate the vertical buttresses in the human midface structure. These morphologic similarities between the human nose and Gothic cathedral will serve as a basis to study the biomechanics of nasal fractures. Identification of structural buttresses in a skeletal structure has important implications for reconstruction as reestablishment of structural continuity restores normal anatomy and architectural stability of the human midface structure.

  11. Isolated osteochondral fracture of the patella without patellar dislocation.

    Science.gov (United States)

    Bhatt, Jay; Montalban, Antonio Santa Cruz; Wang, Kook Hyun; Lee, Hee Du; Nha, Kyung Wook

    2011-01-03

    Chondral fractures of the patella are associated with acute dislocation of the patella. Osteochondral fracture in patellar dislocation is located in the medial facet of the patella. This article presents a case of a 15-year-old female ballerina with isolated displaced osteochondral fracture of the patella without patellar dislocation. She had no history of trauma. A Merchant's view of both knees showed mild subluxation of the patella, a small fragment on the lateral aspect of the knee, and a small defect of the centromedial patella. Axial magnetic resonance imaging (MRI) revealed an osteochondral fragment measuring 13 mm medial to the patella. However, the medial patellofemoral ligament and medial retinaculum were intact. An effusion on the medial side of the patella consistent with hemarthrosis was observed. An absence of a contusion or bone bruise on the lateral femoral condyle was shown. The loose body was removed arthroscopically. Intraoperative findings included a 1.5×2 cm osteochondral fragment. It is unusual that the osteochondral patellar defect site in this patient was in the inferior and central areas of the patella. Patellar chondral fractures without dislocation or patella fracture are rare. Therefore, the possibility of a trivial trauma leading to an osteochondral fracture should be kept in mind in adolescent and young adults who present with knee pain and hemarthrosis. Copyright 2011, SLACK Incorporated.

  12. MANAGEMENT OF COMPLEX OPEN FRACTURES: A PROSPECTIVE STUDY

    Directory of Open Access Journals (Sweden)

    Satyanarayana

    2015-10-01

    Full Text Available BACKGROUND : The incidence of Open fractures is on the rise, due to the increasing Road Traffic Accidents in India. In fact accidents are the leading cause of death in young, healthy individuals now. As the number of compound fractures are flooding the outpatient departments of all the major hospitals a viable and effective strategy has to be in place to manage these patients. The various treatment options available to treat these fractures and t heir effectiveness is the basis for this study. MATERIAL & METHODS : This study was conducted by our unit, from Department of Orthopedics and Traumat ology, Osmania General Hospital /Medical College during September 2012 to September 2014. The study comprises of 40 patients who were treated during this period, the patients selected were with Compound fractures Grade III A and Grade III B of Femur , Tibia and fibula. Various modalities of fixation were used in the management of these patients depending upon the clinical condition of the patient . CONCLUSIONS : External fixation was the mainstay of these fractures. It may be a first aid procedure or a definitive treatment option. The other options like Primary Nailing, biological plating have their own ind ications . Secondary procedures do play their role in the effective management of these complex injuries. All in all the successful management of these limb / life threatening injuries lies in the initial management and early intervention , secure fixation of fractures , prevention of infection and reasonable covering of the wounds.

  13. Intermittent Flow Regimes in Unsaturated Fractured Porous Media

    Science.gov (United States)

    Ghezzehei, T. A.; Or, D.

    2001-12-01

    Flow regimes in unsaturated fractured rocks are significantly influenced by interplay between gravitational and capillary forces and by abrupt changes in media pore space properties. These interactions give rise to complex flow mechanisms that are not amenable to representation by standard continuum theories. Even when the flux of water into the fracture is uniform, actual flow of liquid occurs through preferential pathways. We developed a model for interactions between a uniform flux and local variations in fracture aperture, leading to fragmentation of the liquid into discrete elements (bridges) and subsequent initiation of avalanches. Liquid bridges form and grow in local asperities along the preferential pathways, with subsequent breakup of the bridges at a critical bridge size. The detached bridge has a potential of sweeping other bridges along the pathway downhill from the initiation point, creating an avalanche of growing mass. Consequently, the outflow at the end of the fracture occurs as a series of discrete discharge events. The size and interval of the discharge events depend on the flux of liquid into the fracture and the fracture geometry on the pathway (e.g., number of apertures and aperture sizes). Such complex flow structure was observed in other studies involving gravity-driven unsaturated flow.

  14. Discriminants of prevalent fractures in chronic kidney disease.

    Science.gov (United States)

    Nickolas, Thomas L; Cremers, Serge; Zhang, Amy; Thomas, Valeri; Stein, Emily; Cohen, Adi; Chauncey, Ryan; Nikkel, Lucas; Yin, Michael T; Liu, Xiaowei S; Boutroy, Stephanie; Staron, Ronald B; Leonard, Mary B; McMahon, Donald J; Dworakowski, Elzbieta; Shane, Elizabeth

    2011-08-01

    Patients with chronic kidney disease (CKD) have higher rates of fracture than the general population. Increased bone remodeling, leading to microarchitectural deterioration and increased fragility, may accompany declining kidney function, but there are no reliable methods to identify patients at increased risk for fracture. In this cross-sectional study of 82 patients with predialysis CKD, high-resolution imaging revealed that the 23 patients with current fractures had significantly lower areal density at the femoral neck; total, cortical, and trabecular volumetric bone density; cortical area and thickness; and trabecular thickness. Compared with levels in the lowest tertile, higher levels of osteocalcin, procollagen type-1 N-terminal propeptide, and tartrate-resistant acid phosphatase 5b were associated with higher odds of fracture, even after adjustment for femoral neck T-score. Discrimination of fracture prevalence was best with a femoral neck T-score of -2.0 or less and a value in the upper two tertiles for osteocalcin, procollagen type-1 N-terminal propeptide, or tartrate-resistant acid phosphatase 5b; these values corresponded to the upper half of the normal premenopausal reference range. In summary, these cross-sectional data suggest that measurement of bone turnover markers may increase the diagnostic accuracy of densitometry to identify patients with CKD at high risk for fracture.

  15. Toughness of carbon nanotubes conforms to classic fracture mechanics.

    Science.gov (United States)

    Yang, Lin; Greenfeld, Israel; Wagner, H Daniel

    2016-02-01

    Defects in crystalline structure are commonly believed to degrade the ideal strength of carbon nanotubes. However, the fracture mechanisms induced by such defects, as well as the validity of solid mechanics theories at the nanoscale, are still under debate. We show that the fracture toughness of single-walled nanotubes (SWNTs) conforms to the classic theory of fracture mechanics, even for the smallest possible vacancy defect (~2 Å). By simulating tension of SWNTs containing common types of defects, we demonstrate how stress concentration at the defect boundary leads to brittle (unstable) fracturing at a relatively low strain, degrading the ideal strength of SWNTs by up to 60%. We find that, owing to the SWNT's truss-like structure, defects at this scale are not sharp and stress concentrations are finite and low. Moreover, stress concentration, a geometric property at the macroscale, is interrelated with the SWNT fracture toughness, a material property. The resulting SWNT fracture toughness is 2.7 MPa m(0.5), typical of moderately brittle materials and applicable also to graphene.

  16. Modelling of Specimen Fracture

    Science.gov (United States)

    2013-09-23

    the plate center. An end load of 1.0 MPa was applied. 1 2 3 Modelling of Specimen Fracture – Final Report 11 TR-13-47 Figure 2.5: Crack Geometry Figure...Christopher Bayley DRDC Atlantic Dockyard Laboratory Pacific CFB Esquimalt, Building 199 PO Box 17000, Station Forces Victoria, British Columbia Canada...q The weighting function, q , can be any arbitrary function within the J-integral domain, and must be zero on the domain boundary . An easy function

  17. Image diagnosis of nasal bone fracture

    Energy Technology Data Exchange (ETDEWEB)

    Hirota, Yoshiharu; Shimizu, Yayoi; Iinuma, Toshitaka.

    1988-04-01

    Twenty cases of nasal bone fractures were evaluated as to the types of fractures based upon HRCT findings. Conventional X-Ray films for nasal bones were analyzed and compared with HRCT findings. Nasal bone fractures were classified into lateral and frontal fractures. HRCT images were evaluated in three planes including upper, middle and lower portions of the nasal bone. Fractures favored males of teens. Lateral fracture gave rise to the fractures of the nasal bone opposite to the external force, loosening of the ipsilateral nasomaxillary sutures and fractures of the frontal process of the maxilla. Conventional X-Ray films were reevaluated after HRCT evaluation and indications of nasal bone fractures were determined. In addition to the discontinuity of the nasal dorsum, fracture lines parallel to and beneath the nasal dorsum and indistinct fracture lines along the nasomaxillary sutures are the indication of nasal bone fractures by conventional X-Ray films.

  18. Poromechanical response of naturally fractured sorbing media

    Science.gov (United States)

    Kumar, Hemant

    The injection of CO2 in coal seams has been utilized for enhanced gas recovery and potential CO2 sequestration in unmineable coal seams. It is advantageous because as it enhances the production and significant volumes of CO2 may be stored simultaneously. The key issues for enhanced gas recovery and geologic sequestration of CO2 include (1) Injectivity prediction: The chemical and physical processes initiated by the injection of CO2 in the coal seam leads to permeability/porosity changes (2) Up scaling: Development of full scale coupled reservoir model which may predict the enhanced production, associated permeability changes and quantity of sequestered CO2. (3) Reservoir Stimulation: The coalbeds are often fractured and proppants are placed into the fractures to prevent the permeability reduction but the permeability evolution in such cases is poorly understood. These issues are largely governed by dynamic coupling of adsorption, fluid exchange, transport, water content, stress regime, fracture geometry and physiomechanical changes in coals which are triggered by CO 2 injection. The understanding of complex interactions in coal has been investigated through laboratory experiments and full reservoir scale models are developed to answer key issues. (Abstract shortened by ProQuest.).

  19. Tarlov Cyst Causing Sacral Insufficiency Fracture.

    Science.gov (United States)

    Puffer, Ross C; Gates, Marcus J; Copeland, William; Krauss, William E; Fogelson, Jeremy

    2017-06-01

    Tarlov cysts, also known as perineural cysts, have been described as meningeal dilations of the spinal nerve root sheath between the peri- and endoneurium at the dorsal root ganglion. Most often they are found in the sacrum involving the nerve roots. Normally asymptomatic, they have been reported to present with radiculopathy, paresthesias, and even urinary or bowel dysfunction. Sacral insufficiency has not been a well-documented presentation. The patient is a 38-year-old female who started to develop left low back pain and buttock pain that rapidly progressed into severe pain with some radiation down the posterior aspect of her left leg. There was no recent history of spine or pelvic trauma. These symptoms prompted her initial emergency department evaluation, and imaging demonstrated a large Tarlov cyst with an associated sacral insufficiency fracture. She was noted to have a normal neurological examination notable only for an antalgic gait. She was taken to surgery via a posterior approach and the cyst was identified eccentric to the left. The cyst was fenestrated and the nerve roots identified. Given her large area of bone erosion and insufficiency fractures, fixation of the sacroiliac joints was deemed necessary. Fusion was extended to the L5 vertebral body to buttress the fixation. She tolerated the procedure well and was discharged from the hospital on postoperative day 3. Tarlov cysts of the sacrum can lead to significant bone erosion and subsequent insufficiency fractures, requiring fenestration and in some cases, complex sacropelvic fixation.

  20. Zoledronic acid and clinical fractures and mortality after hip fracture

    DEFF Research Database (Denmark)

    Lyles, Kenneth W; Colón-Emeric, Cathleen S; Magaziner, Jay S

    2007-01-01

    BACKGROUND: Mortality is increased after a hip fracture, and strategies that improve outcomes are needed. METHODS: In this randomized, double-blind, placebo-controlled trial, 1065 patients were assigned to receive yearly intravenous zoledronic acid (at a dose of 5 mg), and 1062 patients were...... assigned to receive placebo. The infusions were first administered within 90 days after surgical repair of a hip fracture. All patients (mean age, 74.5 years) received supplemental vitamin D and calcium. The median follow-up was 1.9 years. The primary end point was a new clinical fracture. RESULTS...... in the two groups. CONCLUSIONS: An annual infusion of zoledronic acid within 90 days after repair of a low-trauma hip fracture was associated with a reduction in the rate of new clinical fractures and with improved survival. (ClinicalTrials.gov number, NCT00046254 [ClinicalTrials.gov].)....

  1. Micromechanical studies of cyclic creep fracture under stress controlled loading

    DEFF Research Database (Denmark)

    van der Giessen, Erik; Tvergaard, Viggo

    1996-01-01

    This paper deals with a study of intergranular failure by creep cavitation under stress-controlled cyclic loading conditions. Loading is assumed to be slow enough that diffusion and creep mechanisms (including grain boundary sliding) dominate, leading to intergranular creep fracture. This study i...

  2. Micromechanical studies of cyclic creep fracture under stress- controlled loading

    NARCIS (Netherlands)

    Giessen, E. van der; Tvergaard, V.

    1996-01-01

    This paper deals with a study of intergranular failure by creep cavitation under stress-controlled cyclic loading conditions. Loading is assumed to be slow enough that diffusion and creep mechanisms (including grain boundary sliding) dominate, leading to intergranular creep fracture. This study is

  3. Colloid retention mechanisms in single, saturated, variable-aperture fractures.

    Science.gov (United States)

    Rodrigues, S N; Dickson, S E; Qu, J

    2013-01-01

    The characterization of fractured aquifers is commonly limited to the methodologies developed for unconsolidated porous media aquifers, which results in many uncertainties. Recent work indicates that fractured rocks remove more particulates than they are conventionally credited for. This research was designed to quantify the number of Escherichia coli RS2-GFP retained in single, saturated, variable-aperture fractures extracted from the natural environment. Conservative solute and E. coli RS2-GFP tracer experiments were used to elucidate the relationships between dominant retention mechanisms, aperture field characteristics, and flow rate. A non-destructive method of determining a surrogate measure of a coefficient of variation (COV(S)) for each fracture was used to better understand the transport behaviour of E. coli RS2-GFP. The results from this research all point to the importance of aperture field characterization in understanding the fate and transport of contaminants in fractured aquifers. The mean aperture was a very important characteristic in determining particulate recovery, so were matrix properties, COV(s), and flow rate. It was also determined that attachment is a much more significant retention mechanism than straining under the conditions employed in this research. Finally, it was demonstrated that the dominant retention mechanism in a fracture varies depending on the specific discharge. An improved understanding of the mechanisms that influence the fate and transport of contaminants through fractures will lead to the development of better tools and methodologies for the characterization of fractured aquifers, as well as the ability to manipulate the relevant mechanisms to increase or decrease retention, depending on the application.

  4. Modeling interfacial fracture in Sierra.

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Arthur A.; Ohashi, Yuki; Lu, Wei-Yang; Nelson, Stacy A. C.; Foulk, James W.,; Reedy, Earl David,; Austin, Kevin N.; Margolis, Stephen B.

    2013-09-01

    This report summarizes computational efforts to model interfacial fracture using cohesive zone models in the SIERRA/SolidMechanics (SIERRA/SM) finite element code. Cohesive surface elements were used to model crack initiation and propagation along predefined paths. Mesh convergence was observed with SIERRA/SM for numerous geometries. As the funding for this project came from the Advanced Simulation and Computing Verification and Validation (ASC V&V) focus area, considerable effort was spent performing verification and validation. Code verification was performed to compare code predictions to analytical solutions for simple three-element simulations as well as a higher-fidelity simulation of a double-cantilever beam. Parameter identification was conducted with Dakota using experimental results on asymmetric double-cantilever beam (ADCB) and end-notched-flexure (ENF) experiments conducted under Campaign-6 funding. Discretization convergence studies were also performed with respect to mesh size and time step and an optimization study was completed for mode II delamination using the ENF geometry. Throughout this verification process, numerous SIERRA/SM bugs were found and reported, all of which have been fixed, leading to over a 10-fold increase in convergence rates. Finally, mixed-mode flexure experiments were performed for validation. One of the unexplained issues encountered was material property variability for ostensibly the same composite material. Since the variability is not fully understood, it is difficult to accurately assess uncertainty when performing predictions.

  5. Challenges in Microseismic Monitoring of Hydrualic Fracturing

    Science.gov (United States)

    Venkataraman, A.; Li, R.

    2011-12-01

    To enhance well productivity, hydraulic fractures are stimulated by injecting fluid and/or gas with proppant into the rock matrix. This results in stress perturbations that induce fractures in the formation releasing minor amounts of seismic energy as microseismic events. Microseismicity can be recorded by properly positioned geophones and is one of the indirect methods that allow us to determine the actual volume of rock that was impacted during and after hydraulic fracturing. Specifically, microseismic data is acquired during hydro-fracture treatments to validate and assist completions, assist in placing wells in the formation, identify frac barriers, and to illuminate faults and potential fault re-activation. In the industry, microseismic data is acquired using geophones deployed in borehole and/or surface arrays. Borehole arrays are more traditional and have been used for nearly 20 years. Event location using borehole data is fairly robust, but azimuth and aperture are limited. Moreover, having dedicated boreholes can be expensive. The newer method of acquiring data is the use of geophones deployed on the surface or in shallow boreholes. Since microseismic events are very small (-4 to -0.5), surface records have weak P and S arrivals that are buried in the noise and traditional event location methods which use arrival time picks cannot be used. Migration based approaches which rely on the power of stacking waveforms is the common approach. However, poor signal-to-noise data and polarity in seismic waves generated by micro-earthquakes can result in uncertainty in event location. In this paper, we will discuss the pros and cons of both arrays, the status of the technology, its limitations and challenges. Specifically, we will focus on applications where industry-academic collaborations could lead to step changes in our understanding of the controls on microseismicity.

  6. Outcome analysis of pelvic ring fractures

    Directory of Open Access Journals (Sweden)

    Sen Ramesh

    2010-01-01

    Full Text Available Background: The behavior of pelvic ring fractures in the long run has been very sparsely studied. The purpose of this study is to assess the long-term outcome of pelvic ring fractures. Materials and Methods: A total of 24 patients with pelvic ring fractures, not involving the acetabulum, were followed up for an average duration of 33 months (range 24-49 months. The clinicoradiological assessment was done using the pelvic scoring system adapted from Cole et al. Parameters assessed included sacroiliac (SI joint involvement and, among SI joint injuries, the presence of a fracture disruption and the degree of displacement. Results: Pain and limp were present in 13 patients (54.2% each and residual working disability in 9 patients (37.5%. The overall Cole′s pelvic score was 31.3 ± 7.02 of a total score of 40. The average pelvic score in patients with SI disruption was 29.2 ± 6.75; much lower than patients without SI disruption with an average score of 34.9 ± 6.25 reaching statistical significance. The pelvic score among patients with a displacement ≤10 mm was 33.0 ± 3.92 and with a displacement> 10 mm 25.88 ± 7.14. The difference was statistically significant. Conclusions: Pelvic ring injuries can lead to long term problems significantly. The involvement of the SI joint affects the long-term outcome adversely, more so if the residual displacement is> 10 mm. The pelvic scoring system is comprehensive and depicts subtle differences in the outcome, which the individual parameters of the assessment fail to show.

  7. Fracture Detection and Mapping

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, Norman E.; Iovenitti, Joseph L.

    1986-01-21

    Because the costs of drilling, completing, and testing a well can be extremely high, it is important to develop better tools and methods for locating high permeability zones prior to drilling, and to develop better tools and methods for identifying and characterizing major fracture zones during the drilling and well testing stages. At the recommendation of the LBL Industry Review Panel on Geothermal Reservoir Technology, we organized and convened a one-day workshop this past July to discuss various aspects of DOE's current and planned activities in fracture detection, to review the geothermal industry's near-term and long-term research needs, to determine the priority of those needs, to disseminate to industry the status of research in progress, and to discuss the possibility of future joint research between industry and DOE. In this paper we present a brief overview of the workshop from the perspective of those who participated in it and provided us with written comments to a questionnaire that was distributed.

  8. Fracture detection and mapping

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, N.E.; Iovenitti, J.L.

    1986-03-01

    Because the costs of drilling, completing, and testing a well can be extremely high, it is important to develop better tools and methods for locating high permeability zones prior to drilling, and to develop better tools and methods for identifying and characterizing major fracture zones during the drilling and well testing stages. At the recommendation of the LBL Industry Review Panel on Geothermal Reservoir Technology, we organized and convened a one-day workshop this past July to discuss various aspects of DOE's current and planned activities in fracture detection, to review the geothermal industry's near-term and long-term research needs, to determine the priority of those needs, to disseminate to industry the status of research in progress, and to discuss the possibility of future joint research between industry and DOE. In this paper we present a brief overview of the workshop from the perspective of those who participated in it and provided us with written comments to a questionnaire that was distributed.

  9. Diplopia and orbital wall fractures

    NARCIS (Netherlands)

    Boffano, P.; Roccia, F.; Gallesio, C.; Karagozoglu, K.H.; Forouzanfar, T.

    2014-01-01

    Diplopia is a symptom that is frequently associated with orbital wall fractures. The aim of this article was to present the incidence and patterns of diplopia after orbital wall blow-out fractures in 2 European centers, Turin and Amsterdam, and to identify any correlation between this symptom and su

  10. Cough-induced rib fractures.

    Science.gov (United States)

    Sano, Atsushi; Tashiro, Ken; Fukuda, Tsutomu

    2015-10-01

    Occasionally, patients who complain of chest pain after the onset of coughing are diagnosed with rib fractures. We investigated the characteristics of cough-induced rib fractures. Between April 2008 and December 2013, 17 patients were referred to our hospital with chest pain after the onset of coughing. Rib radiography was performed, focusing on the location of the chest pain. When the patient had other signs and symptoms such as fever or persistent cough, computed tomography of the chest was carried out. We analyzed the data retrospectively. Rib fractures were found in 14 of the 17 patients. The age of the patients ranged from 14 to 86 years (median 39.5 years). Ten patients were female and 4 were male. Three patients had chronic lung disease. There was a single rib fracture in 9 patients, and 5 had two or more fractures. The middle and lower ribs were the most commonly involved; the 10th rib was fractured most frequently. Cough-induced rib fractures occur in every age group regardless of the presence or absence of underlying disease. Since rib fractures often occur in the lower and middle ribs, rib radiography is useful for diagnosis. © The Author(s) 2015.

  11. Bilateral acetabular fracture without trauma

    OpenAIRE

    De Rosa, M. A.; G. Maccauro; D’Arienzo, M.

    1999-01-01

     In the absence of trauma fracture of the acetabulum is an extremely rare injury. We describe a 70 year old man who spontaneously developed fractures in both acetabulae due to bony insufficiency. It was successfully treated by bilateral total hip replacement.

  12. Epidemiological study on talus fractures

    Directory of Open Access Journals (Sweden)

    Marcos Hideyo Sakaki

    2014-08-01

    Full Text Available Objective:To analyze the characteristics of patients with talus fractures and the injuries that they present.Methods:Retrospective analysis on patients hospitalized in the Institute of Orthopedics and Traumatology, Hospital das Clínicas, School of Medicine of the University of São Paulo, between 2006 and 2011, with talus fractures. Patient profile parameters, risk factors, fracture characteristics, treatment data and acute complications were analyzed.Results:Analysis on 23 cases showed that men were more affected than women, with a ratio of 4.8:1. The most frequent trauma mechanism was traffic accidents, followed by falls from a height. The most frequent type of fracture was at the neck of the talus, with 17 cases. Among the 23 cases, seven had peritalar dislocation at the time of presentation, four had exposed fractures and 11 presented other associated fractures. The mean length of time between the trauma and the definitive treatment was six days, while the mean length of hospital stay was 11 days. Three patients presented acute postoperative complications.Conclusion:Talus fractures occurred most commonly in the region of the talar neck and most frequently in young males who suffered high-energy trauma. In almost half of the cases, there were other associated fractures. The length of hospital stay was 11 days.

  13. Polymer liquids fracture like solids

    DEFF Research Database (Denmark)

    Huang, Qian; Hassager, Ole

    2017-01-01

    While fracture in brittle solids has been studied for centuries until today, there are few studies on fracture in polymer liquids. Recent developments in experimental techniques, especially the combination of controlled filament stretching rheometry and high speed imaging, have opened new windows...

  14. Global Trends in Maxillofacial Fractures

    OpenAIRE

    Lee, Kai

    2012-01-01

    Background The etiology, demographics, fracture site in facial injury patients have been reported worldwide. However, few studies have attempted to identify changes in maxillofacial fractures over time periods and between countries. The statistics are vastly different due to variations in social, environmental, and cultural factors.

  15. Excess mortality following hip fracture

    DEFF Research Database (Denmark)

    Abrahamsen, B; van Staa, T; Ariely, R;

    2009-01-01

    Summary This systematic literature review has shown that patients experiencing hip fracture after low-impact trauma are at considerable excess risk for death compared with nonhip fracture/community control populations. The increased mortality risk may persist for several years thereafter, highlig...

  16. Diplopia and orbital wall fractures

    NARCIS (Netherlands)

    Boffano, P.; Roccia, F.; Gallesio, C.; Karagozoglu, K.H.; Forouzanfar, T.

    2014-01-01

    Diplopia is a symptom that is frequently associated with orbital wall fractures. The aim of this article was to present the incidence and patterns of diplopia after orbital wall blow-out fractures in 2 European centers, Turin and Amsterdam, and to identify any correlation between this symptom and

  17. Fracture mechanics in pavement design

    CSIR Research Space (South Africa)

    Denneman, E

    2009-07-01

    Full Text Available effects. Examples of the use of fracture mechanics providing an alternative to these conventional design parameters are given in the paper. The paper shows that although much further development is required before fracture mechanics can be relied upon...

  18. Isolated Transverse Sacrum Fracture: A Case Report

    Directory of Open Access Journals (Sweden)

    Cemil Kavalci

    2011-01-01

    Full Text Available Sacral fracture commonly results from high-energy trauma. Most insufficiency fractures of the sacrum are seen in women after the age of 70. Fractures of the sacrum are rare and generally combined with a concomitant pelvic fracture. Transverse sacral fractures are even less frequent which constitute only 3–5% of all sacral fractures. This type of fractures provide a diagnostic challenge. We report a unique case of isolated transverse fracture of sacrum in a young man sustained low-energy trauma. The patient presented to our emergency department after several hours of injury, and diagnosed by clinical features and roentgenogram findings.

  19. Hydraulic fracturing with chlorine dioxide cleanup

    Energy Technology Data Exchange (ETDEWEB)

    Williams, D.A.; Newlove, J.C.; Horton, R.L.

    1990-10-23

    This patent describes a method for fracturing a subterranean formation penetrated by a wellbore. It comprises: injecting a fracturing fluid into the formation to form a vertical fracture therein, the fracturing fluid being gelled with a polymer selected from guar, guar derivatives, acrylamide, acrylamide derivatives, cellulose, cellulose derivatives, and mixtures thereof and crosslinked with an organometallic crosslinking compound and having temperature stability above about 175{degrees} F.; packing the fracture with particulate propping agent; backflowing fluids from the formation through the propped fracture to remove a portion of the polymer; injecting at matrix rates sufficient aqueous solution of chlorine dioxide down the wellbore and into the propped fracture to penetrate at least 60 feet of the propped fracture length and contact polymer in the fracturing fluid and polymer residue in the propped fracture and on the fracture walls, the amount of the chlorine dioxide in the aqueous medium being sufficient to degrade polymer in the fracturing fluid and polymer residue; permitting the chlorine dioxide to remain in contact with the polymer in the fracturing fluid and with the polymer residue on the fracture walls and in the fracture for sufficient time to degrade the polymer thereby reducing the fracturing fluid viscosity and dissolving portions of the polymer residue; and flowing formation fluid from the formation through the propped fracture and into the wellbore to remove substantial portions of the polymer and degraded polymer from the fracture.

  20. Lead Poisoning Prevention Tips

    Science.gov (United States)

    ... or removed safely. How are children exposed to lead? Lead-based paint and lead contaminated dust are ... What can be done to prevent exposure to lead? It is important to determine the construction year ...

  1. Lead (Pb) Air Pollution

    Science.gov (United States)

    ... States Environmental Protection Agency Search Search Lead (Pb) Air Pollution Share Facebook Twitter Google+ Pinterest Contact Us As ... and protect aquatic and terrestrial ecosystems. Lead (Pb) Air Pollution Lead Air Pollution Basics How does lead get ...

  2. Distal clavicle fractures in children☆

    Science.gov (United States)

    Labronici, Pedro José; da Silva, Ricardo Rodrigues; Franco, Marcos Vinícius Viana; Labronici, Gustavo José; Pires, Robinson Esteves Santos; Franco, José Sergio

    2015-01-01

    Objective To analyze fractures of the distal clavicle region in pediatric patients. Methods Ten patients between the ages of five to eleven years (mean of 7.3 years) were observed. Nine patients were treated conservatively and one surgically. All the fractures were classified using the Nenopoulos classification system. Results All the fractures consolidated without complications. Conservative treatment was used for nine patients, of whom three were in group IIIB, three IIb, two IIa and one IV. The only patient who was treated surgically was a female patient of eleven years of age with a group IV fracture. Conclusion The treatment indication for distal fractures of the clavicle in children should be based on the patient's age and the displacement of the fragments. PMID:26962489

  3. Pathogenesis of osteoporotic hip fractures.

    Science.gov (United States)

    McClung, Michael R

    2003-01-01

    Osteoporosis is characterized late in the course of the disease by an increased risk of fracture, particularly in the elderly. It occurs in both sexes, affecting approximately 8 million women and 2 million men aged > or = 50 years (1). While low bone density is a predictor of fractures, it is not the only determinant of fracture risk. Other factors include advanced age, altered bone quality, a personal or family history of falls, frailty, poor eyesight, debilitating diseases, and high bone turnover. A diet with sufficient calcium and vitamin D is important to minimize bone loss and, along with regular exercise, to maintain muscle strength. Bisphosphonates have been shown to reduce the risk of hip fracture. For elderly patients, the use of hip protectors may be used as a treatment of last resort. Regardless of the age of the patient, individual patient risk factors must be considered to target appropriate treatment and prevent fracture.

  4. Fractures of the proximal humerus

    DEFF Research Database (Denmark)

    Brorson, Stig

    2013-01-01

    Fractures of the proximal humerus have been diagnosed and managed since the earliest known surgical texts. For more than four millennia the preferred treatment was forceful traction, closed reduction, and immobilization with linen soaked in combinations of oil, honey, alum, wine, or cerate....... The bandages were further supported by splints made of wood or coarse grass. Healing was expected in forty days. Different fracture patterns have been discussed and classified since Ancient Greece. Current classification of proximal humeral fractures mainly relies on the classifications proposed by Charles......, classification of proximal humeral fractures remains a challenge for the conduct, reporting, and interpretation of clinical trials. The evidence for the benefits of surgery in complex fractures of the proximal humerus is weak. In three systematic reviews I studied the outcome after locking plate osteosynthesis...

  5. Distal clavicle fractures in children

    Directory of Open Access Journals (Sweden)

    Pedro José Labronici

    2016-02-01

    Full Text Available ABSTRACT OBJECTIVE: To analyze fractures of the distal clavicle region in pediatric patients. METHODS: Ten patients between the ages of five to eleven years (mean of 7.3 years were observed. Nine patients were treated conservatively and one surgically. All the fractures were classified using the Nenopoulos classification system. RESULTS: All the fractures consolidated without complications. Conservative treatment was used for nine patients, of whom three were in group IIIB, three IIb, two IIa and one IV. The only patient who was treated surgically was a female patient of eleven years of age with a group IV fracture. CONCLUSION: The treatment indication for distal fractures of the clavicle in children should be based on the patient's age and the displacement of the fragments.

  6. Numerical Analysis on the Formation of Fracture Network during the Hydraulic Fracturing of Shale with Pre-Existing Fractures

    Directory of Open Access Journals (Sweden)

    Jianming He

    2017-05-01

    Full Text Available In this paper, configurations of pre-existing fractures in cubic rock blocks were investigated and reconstructed for the modeling of experimental hydraulic fracturing. The fluid-rock coupling process of hydraulic fracturing was simulated based on the displacement discontinuities method. The numerical model was validated against the related laboratory experiments. The stimulated fracture configurations under different conditions can be clearly shown using the validated numerical model. First, a dominated fracture along the maximum principle stress direction is always formed when the stress difference is large enough. Second, there are less reopened pre-existing fractures, more newly formed fractures and less shear fractures with the increase of the cohesion value of pre-existing fractures. Third, the length of the stimulated shear fracture decreases rapidly with the increase of the friction coefficient, while the length of the tensile fracture has no correlation to the fiction coefficient. Finally, the increase of the fluid injection rate is favorable to the formation of a fracture network. The unfavorable effects of the large stress difference and the large cohesion of pre-existing fractures can be partly suppressed by an increase of the injection rate in the hydraulic fracturing treatment. The results of this paper are useful for understanding fracture propagation behaviors during the hydraulic fracturing of shale reservoirs with pre-existing fractures.

  7. Fracture resistance on aggregate bridging crack in concrete

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiufang; XU Shilang

    2007-01-01

    Fracture toughening exhibited in quasi-brittle materials such as concrete is often mainly related to the action of aggregate bridging,which leads to the presence of a fracture process zone ahead of stress-free cracks in such materials.In this investigation,the fracture resistance induced by aggregate bridging,denoted by GI-bridging,is the primary focus.In order to quantitatively determine it,a general analytical formula is firstly developed,based on the definition of fracture energy by Hillerborg.After this,we further present the calculated procedures of determining this fracture resistance from the recorded load vs.crack opening displacement curve.Then,both numerical simulations and fracture experiments are performed on concrete three-point bending beams.Utilizing the obtained load against crack opening displacement curve,the value of GI-bridging at any crack extension as well as the change of GI-bridging with the crack extension is examined.It is found that GI-bridging will firstly increase with the development of crack and then stay constant once the initial crack tip opening displacement reaches the characteristic crack opening displacement w0.The effects of material strength and specimen depth on this fracture resistance are also investigated.The results reveal that the values of GI-bridging of different specimens at any crack propagation are strongly associated with the values of fracture energy of specimens.If the values of fracture energy between different specimens are comparable,the differences between GI-bridging are ignored.Instead,if values of fracture energy are different,the GI-bridging will be different.This shows that for specimens with different strengths,GI-bridging will change greatly whereas for specimens that are different in depth,whether GI-bridging exhibits size effect depends on whether the fracture energy of specimens considered in the calculation of GI-bridging is assumed to be a size-dependent material parameter.

  8. Circumstances leading to injurious falls in older men and women in the Netherlands.

    Science.gov (United States)

    Boyé, Nicole D A; Mattace-Raso, Francesco U S; Van der Velde, Nathalie; Van Lieshout, Esther M M; De Vries, Oscar J; Hartholt, Klaas A; Kerver, Albert J H; Bruijninckx, Milko M M; Van der Cammen, Tischa J M; Patka, Peter; Van Beeck, Ed F

    2014-08-01

    Fall-induced injuries in persons aged 65 years and older are a major public health problem. Data regarding circumstances leading to specific injuries, such as traumatic brain injury (TBI) and hip fractures in older adults are scarce. To investigate the activity distributions leading to indoor and outdoor falls requiring an emergency department (ED) visit, and those resulting in TBIs and hip fractures. 5880 older adults who visited the ED due to a fall. Data is descriptive and stratified by age and gender. Two-thirds of all falls occurred indoors. However, there were higher proportions of outdoor falls at ages 65-79 years (48%). Walking up or down stairs (51%) and housekeeping (17%) were the most common indoor activities leading to a TBIs. Walking (42%) and sitting or standing (16%) was the most common indoor activities leading to a hip fracture. The most common outdoor activities were walking (61% for TBIs and 57% for hip fractures) and cycling (10% for TBIs and 24% for hip fractures). In the present study we found that the indoor activities distribution leading to TBIs and hip fractures differed. Notably, about half of the traumatic brain injuries and hip fractures in men and women aged 65-79 years occurred outdoors. This study provides new insights into patterns leading to injurious falls by age, gender and injury type, and may guide the targeting of falls prevention at specific activities and risk groups, including highly functional older men and women. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. La cláusula ‘ex fide bona’ y su influencia en el ‘quantum respondeatur’ como herramienta para recuperar el equilibrio patrimonial en derecho romano

    Directory of Open Access Journals (Sweden)

    Lilian C. San Martín Neira

    2015-06-01

    Full Text Available Este artículo se refiere a la relación existente entre la cláusula ex fide bona y la cuantía de la condena en derecho romano. Mediante la exégesis de dos pasajes del Digesto se pone en evidencia que, gracias a la elasticidad de la cláusula ex fide bona, los juristas romanos utilizaron el quantum respondeatur como un mecanismo para restablecer el equilibrio patrimonial, excluyendo de la summa condemnationis cantidades que en principio habrían debido incluirse. En consecuencia, en Roma la buena fe no era solo un mecanismo de integración del contrato mediante la ampliación de las obligaciones contraídas por las partes, sino también un mecanismo de atenuación de dichas obligaciones, cuando su exigencia en términos literales resultaba contraria al equilibrio propio de los contratos de buena fe.

  10. Quantitative NDI integration with probabilistic fracture mechanics for the assessment of fracture risk in pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Kurz, Jochen H.; Cioclov, Dragos; Dobmann, Gerd; Boiler, Christian [Fraunhofer Inst. fuer Zerstoerungsfreie Pruefverfahren (IZFP), Saarbruecken (Germany)

    2009-07-01

    In the context of probabilistic paradigm of fracture risk assessment in structural components a computer simulation rationale is presented which has at the base the integration of Quantitative Non-destructive Inspection and Probabilistic Fracture Mechanics. In this study the static failure under static loading is assessed in the format known as Failure Assessment Diagram (FAD). The key concept in the analysis is the stress intensity factor (SIF) which accounts on the geometry of the component and the size of a pre-existent defect of a crack nature. FAD assessments can be made in deterministic sense, which yields the end result in dual terms of fail/not-fail. The fracture risk is evaluated in probabilistic terms. The superposed probabilistic pattern over the deterministic one (in mean sense) is implemented via Monte-Carlo sampling. The probabilistic fracture simulation yields a more informative analysis in terms of probability of failure. An important feature of the PVrisk software is the ability to simulate the influence of the quality and reliability of non-destructive inspection (NDI). It is achieved by integrating, algorithmically. probabilistic FAD analysis and the Probability of Detection (POD). The POD information can only be applied in a probabilistic analysis and leads to a refinement of the assessment. By this means, it can be ascertained the decrease of probability of failure (increase of reliability) when POD-characterized NDI is applied. Therefore, this procedure can be used as a tool for inspection based life time conceptions. In this paper results of sensitivity analyses of the fracture toughness are presented with the aim to outline, in terms of non-failure probabilities, the benefits of applying NDI, in various qualities, in comparison with the situation when NDI is lacking. (orig.)

  11. Complex multilevel lumbar spine fractures with transverse sacral fracture

    Directory of Open Access Journals (Sweden)

    Kshitij Chaudhary

    2011-01-01

    Full Text Available We report an unusual and complex case of spinal trauma in a 17-year-old boy who presented with a transverse sacral fracture associated with multiple-level lumbar fractures, paraparesis, and bladder involvement. A two-stage surgery was performed. The lumbar spine fractures were treated with posterior instrumented correction of displacements, followed by anterior instrumentation and fusion. The sacral fracture was left untreated. At 5-year followup, the patient had complete neurological recovery except for the right L5 root function. The long-segment lumbar fusion and the untreated displaced sacral fracture contributed to spinal imbalance, due to which the patient is now able to stand only in a crouched posture. Determining the optimal treatment for the case is presented due to the relative rarity of transverse sacral fracture and paucity of evidence-based treatment approaches. In patients with associated lumbar spine fractures that require extension of instrumentation to the upper lumbar spine, it is critical to restore sacropelvic alignment to achieve spinal balance. Adequate reduction of sacropelvic anatomy can be achieved with iliac screw fixation.

  12. Effect of nano/micro B4C and SiC particles on fracture properties of aluminum 7075 particulate composites under chevron-notch plane strain fracture toughness test

    Science.gov (United States)

    Morovvati, M. R.; Lalehpour, A.; Esmaeilzare, A.

    2016-12-01

    Reinforcing aluminum with SiC and B4C nano/micro particles can lead to a more efficient material in terms of strength and light weight. The influence of adding these particles to an aluminum 7075 matrix is investigated using chevron-notch fracture toughness test method. The reinforcing factors are type, size (micro/nano), and weight percent of the particles. The fracture parameters are maximum load, notch opening displacement, the work up to fracture and chevron notch plane strain fracture toughness. The findings demonstrate that addition of micro and nano size particles improves the fracture properties; however, increasing the weight percent of the particles leads to increase of fracture properties up to a certain level and after that due to agglomeration of the particles, the improvement does not happen for both particle types and size categories. Agglomeration of particles at higher amounts of reinforcing particles results in improper distribution of particles and reduction in mechanical properties.

  13. A Rare Entity: Bilateral First Rib Fractures Accompanying Bilateral Scapular Fractures

    Directory of Open Access Journals (Sweden)

    Gultekin Gulbahar

    2015-01-01

    Full Text Available First rib fractures are scarce due to their well-protected anatomic locations. Bilateral first rib fractures accompanying bilateral scapular fractures are very rare, although they may be together with scapular and clavicular fractures. According to our knowledge, no case of bilateral first rib fractures accompanying bilateral scapular fractures has been reported, so we herein discussed the diagnosis, treatment, and complications of bone fractures due to thoracic trauma in bias of this rare entity.

  14. Coupled transport, mixing and biogeochemical reactions in fractured media: experimental observations and modelling at the Ploemeur fractured rock observatory

    Science.gov (United States)

    Le Borgne, T.; Bochet, O.; Klepikova, M.; Kang, P. K.; Shakas, A.; Aquilina, L.; Dufresne, A.; Linde, N.; Dentz, M.; Bour, O.

    2016-12-01

    Transport processes in fractured media and associated reactions are governed by multiscale heterogeneity ranging from fracture wall roughness at small scale to broadly distributed fracture lengths at network scale. This strong disorder induces a variety of emerging phenomena, including flow channeling, anomalous transport and heat transfer, enhanced mixing and reactive hotspot development. These processes are generally difficult to isolate and monitor in the field because of the high degree of complexity and coupling between them. We report in situ experimental observations from the Ploemeur fractured rock observatory (http://hplus.ore.fr/en/ploemeur) that provide new insights on the dynamics of transport and reaction processes in fractured media. These include dipole and push pull tracer tests that allow understanding and modelling anomalous transport processes characterized by heavy-tailed residence time distributions (Kang et al. 2015), thermal push pull tests that show the existence of highly channeled flow with a strong control on fracture matrix exchanges (Klepikova et al. 2016) and time lapse hydrogeophysical monitoring of saline tracer tests that allow quantifying the distribution of transport length scales governing dispersion processes (Shakas et al. 2016). These transport processes are then shown to induce rapid oxygen delivery and mixing at depth leading to massive biofilm development (Bochet et al., in prep.). Hence, this presentation will attempt to link these observations made at different scales to quantify and model the coupling between flow channeling, non-Fickian transport, mixing and chemical reactions in fractured media. References: Bochet et al. Biofilm blooms driven by enhanced mixing in fractured rock, in prep. Klepikova et al. 2016, Heat as a tracer for understanding transport processes in fractured media: theory and field assessment from multi-scale thermal push-pull tracer tests, Water Resour. Res. 52Shakas et al. 2016, Hydrogeophysical

  15. Definition, classification and treatment of destructive fractures

    Directory of Open Access Journals (Sweden)

    FANG Guo-jun

    2012-02-01

    Full Text Available 【Abstract】 Destructive injury is defined as a very serious damage both to the bone and the soft tissues. But in clinical practice we found that in some fracture cases, the damage to soft tissues is not as severe as 揹estructive injury?indicates, whereas comminuted fractures still cannot show the severity of bone damage. Therefore we proposed a new term 揹estructive fractures?after combining the definition of destructive injury with typical clinic cases. Destructive fractures refer to the fractures whose osseous tissues are damaged too seriously to be repaired, but soft tissues, nerves and veins are less severely injured and can be repaired. From the year 2001 to 2010, 75 cases of destructive fractures were admitted in our department. According to whether the fractures interlinked with the external environment, together with the fracture sites, they were divided into 6 types: a1 type, closed diaphysis destructive fracture; a2 type, open diaphysis destructive fracture; b1 type, closed joint-involved destructive fracture; b2 type, open joint-involved destructive fracture; c1 type, closed mixed destructive fracture; c2 type, open mixed destructive fracture. Corresponding clinical treatments were conducted for each type.The new classification criterion of destructive fracture is simple and practical and thus can be used as an important guide to make reasonable treatment plans for destructive fractures. Key words: Fracture, bone; Classification; Therapeutics

  16. Interlaminar fracture in carbon fiber/thermoplastic composites

    Science.gov (United States)

    Hinkley, J. A.; Bascom, W. D.; Allred, R. E.

    1990-01-01

    The surfaces of commercial carbon fibers are generally chemically cleaned or oxidized and then coated with an oligomeric sizing to optimize their adhesion to epoxy matrix resins. Evidence from fractography, from embedded fiber testing and from fracture energies suggests that these standard treatments are relatively ineffective for thermoplastic matrices. This evidence is reviewed and model thermoplastic composites (polyphenylene oxide/high strain carbon fibers) are used to demonstrate how differences in adhesion can lead to a twofold change in interlaminar fracture toughness. The potential for improved adhesion via plasma modification of fiber surfaces is discussed. Finally, a surprising case of fiber-catalyzed resin degradation is described.

  17. Considerations for the Management of Medial Orbital Wall Blowout Fracture

    Science.gov (United States)

    Park, Youngsoo; Chung, Kyu Jin

    2016-01-01

    Recently, diagnoses of and operations for medial orbital blowout fracture have increased because of the development of imaging technology. In this article, the authors review the literature, and overview the accumulated knowledge about the orbital anatomy, fracture mechanisms, surgical approaches, reconstruction materials, and surgical methods. In terms of surgical approaches, transcaruncular, transcutaneous, and transnasal endoscopic approaches are discussed. Reconstruction methods including onlay covering, inlay implantation, and repositioning methods are also discussed. Consideration and understanding of these should lead to more optimal outcomes. PMID:27218019

  18. Modelisation of transport in fractured media with a smeared fractures modeling approach: special focus on matrix diffusion process.

    Science.gov (United States)

    Fourno, A.; Grenier, C.; Benabderrahmane, H.

    2003-04-01

    Modeling flow and transport in natural fractured media is a difficult issue due among others to the complexity of the system, the particularities of the geometrical features, the strong parameter value contrasts between the fracture zones (flow zones) and the matrix zones (no flow zones). This lead to the development of dedicated tools like for instance discrete fracture network models (DFN). We follow here another line applicable for classical continuous modeling codes. The fracture network is not meshed here but presence of fractures is taken into account by means of continuous heterogeneous fields (permeability, porosity, head, velocity, concentration ...). This line, followed by different authors, is referred as smeared fracture approach and presents the following advantages: the approach is very versatile because no dedicated spatial discretization effort is required (we use a basic regular mesh, simulations can be done on a rough mesh saving computer time). This makes this kind of approach very promising for taking heterogeneity of properties as well as uncertainties into account within a Monte Carlo framework for instance. Furthermore, the geometry of the matrix blocks where transfers proceed by diffusion is fully taken into account contrary to classical simplified 1D approach for instance. Nevertheless continuous heterogeneous field representation of a fractured medium requires a homogenization process at the scale of the mesh considered. Literature proves that this step of homogenization for transport is still a challenging task. Consequently, the level precision of the results has to be estimated. We precedently proposed a new approach dedicated to Mixed and Hybrid Finite Element approach. This numerical scheme is very interesting for such highly heterogeneous media and in particular guaranties exact conservation of mass flow for each mesh leading to good transport results. We developed a smeared fractures approach to model flow and transport limited to

  19. Lead Aprons Are a Lead Exposure Hazard.

    Science.gov (United States)

    Burns, Kevin M; Shoag, Jamie M; Kahlon, Sukhraj S; Parsons, Patrick J; Bijur, Polly E; Taragin, Benjamin H; Markowitz, Morri

    2017-05-01

    To determine whether lead-containing shields have lead dust on the external surface. Institutional review board approval was obtained for this descriptive study of a convenience sample of 172 shields. Each shield was tested for external lead dust via a qualitative rapid on-site test and a laboratory-based quantitative dust wipe analysis, flame atomic absorption spectrometry (FAAS). The χ(2) test was used to test the association with age, type of shield, lead sheet thickness, storage method, and visual and radiographic appearance. Sixty-three percent (95% confidence interval [CI]: 56%-70%) of the shields had detectable surface lead by FAAS and 50% (95% CI: 43%-57%) by the qualitative method. Lead dust by FAAS ranged from undetectable to 998 μg/ft(2). The quantitative detection of lead was significantly associated with the following: (1) visual appearance of the shield (1 = best, 3 = worst): 88% of shields that scored 3 had detectable dust lead; (2) type of shield: a greater proportion of the pediatric patient, full-body, and thyroid shields were positive than vests and skirts; (3) use of a hanger for storage: 27% of shields on a hanger were positive versus 67% not on hangers. Radiographic determination of shield intactness, thickness of interior lead sheets, and age of shield were unrelated to presence of surface dust lead. Sixty-three percent of shields had detectable surface lead that was associated with visual appearance, type of shield, and storage method. Lead-containing shields are a newly identified, potentially widespread source of lead exposure in the health industry. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  20. Mechanisms of intergranular fracture

    Energy Technology Data Exchange (ETDEWEB)

    Farkas, D. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Materials Science and Engineering

    1999-08-01

    The authors present a study of the atomistic mechanisms of crack propagation along grain boundaries in metals and alloys. The failure behavior showing cleavage crack growth and/or crack-tip dislocation emission is demonstrated using atomistic simulations for an embedded-atom model. The simulations follow the quasi-equilibrium growth of a crack as the stress intensity applied increases. Dislocations emitted from crack tips normally blunt the crack and inhibit cleavage, inducing ductile behavior. When the emitted dislocations stay near the crack tip (sessile dislocations), they do blunt the crack but brittle cleavage can occur after the emission of a sufficient number of dislocations. The fracture process occurs as a combination of dislocation emission/micro-cleavage portions that are controlled by the local atomistic structure of the grain boundary. The grain boundary is shown to be a region where dislocation emission is easier, a mechanism that competes with the lower cohesive strength of the boundary region.

  1. Fracture of the talar neck associated with a compression fracture of the calcaneocuboid joint in a 5-year-old child: a case report.

    Science.gov (United States)

    Godoy-Santos, A L; Albuquerque, D M; Diniz-Fernandes, T; Rammelt, S

    2013-09-01

    The objectives of this present case study are to report a rare combination of a displaced talar neck fracture with a compression fracture of the calcaneocuboid joint in a 5-year-old child and to describe its radiological features, surgical treatment and clinical outcome. A 5-year-old male boy was injured in a car accident in which his left foot underwent one of the tires. On arrival at the hospital, a displaced talar neck fracture associated both with a cuboid fracture and compression of the articular surface of the cuboid at the calcaneocuboid join was identified. Fractures were fixed surgically. Leg was protected with a below-knee plaster split immobilization and non-weight-bearing for 5 weeks. After that period, the patient initiated a rehabilitation protocol with active and passive motion exercises. Fractures and fracture dislocations at the mid-tarsal joint have an important impact on the global foot function because malunion can result in post-traumatic arthritis and three-dimensional deformities of the foot. If a cuboid compression fracture is not reduced properly, it can result in the shortening of the lateral column with the development of an abduction, pronation and flat foot deformity. A talar neck fracture, if unreduced, can result in medial column displacement and rotational dislocation of the talar head, leading to a subluxation in the talonavicular joint with severe restriction of foot function. With early surgical treatment and open reduction and internal fixation, our patient recovered from the accident without having symptoms of pain, avascular necrosis, postoperative foot deformities or neurovascular deficits. The combination of a displaced talar neck fracture with a compression fracture of the calcaneocuboid joint in children usually requires correct diagnoses and early treatment with anatomic reduction and internal fixation to prevent severe post-traumatic deformities. V.

  2. Early history of scapular fractures.

    Science.gov (United States)

    Bartoníček, Jan; Kozánek, Michal; Jupiter, Jesse B

    2016-01-01

    The first to use the term Scapula was Vesalius (1514-1564) and thus it has remained ever since. Probably the oldest injured scapula, from 250 million years ago, was described by Chinese authors of a skeletal examination of a fossilised remains of a dinosaur Yangchuanosaurus hepingensis. In humans, the oldest known scapular fractures date back to the prehistoric and early historic times. In ancient times, a fracture of acromion was described in the treatises of Hippocrates. Early modern history of the treatment of scapular fractures is closely interlinked with the history of the French surgery. The first to point out the existence of these fractures were Petit, Du Verney and Desault in the 18th century. The first study devoted solely to scapular fractures was published by Traugott Karl August Vogt in 1799. Thomas Callaway published in 1849 an extensive dissertation on injuries to the shoulder girdle, in which he discussed a number of cases known at that time. The first radiograph of a scapular fracture was published by Petty in 1907. Mayo Robson (1884), Lambotte (1913) and Lane (1914) were pioneers in the surgical treatment of these fractures, followed in 1923 by the French surgeons Lenormat, Dujarrier and Basset. The first internal fixation of the glenoid fossa, including a radiograph, was published by Fischer in 1939.

  3. Spontaneous bilateral fracture of patella.

    Science.gov (United States)

    Moretti, Biagio; Speciale, Domenico; Garofalo, Raffaele; Moretti, Lorenzo; Patella, Silvio; Patella, Vittorio

    2008-03-01

    Bilateral patellae fractures represent a rare entity, accounting for approximately 2.9% of all lesions interesting in this anatomical district. In most cases found in the published work, they are described as stress fractures or as complications of chronic diseases such as osteoporosis, renal failure and secondary hyperparathyroidism. Although many pathogenetic mechanisms have been supposed, none have been proved for certain. Insufficiency fractures of the patellae are rare events and no data has been published on their incidence. We present a case of bilateral fracture of the patellae due to an indirect trauma occurring in an 85-year-old patient affected by Parkinson's disease, osteoporosis and diffuse degenerative osteoarthritis. X-ray of the knees (anteroposterior and lateral) and magnetic resonance imaging evaluation confirmed the fractures. The patient was treated conservatively. She had a good result, returning to her previous autonomous ambulation. This case is unusual because there was no direct trauma to the knees because of bilaterality, but confirmed previous observations about insufficiency fractures of patellae in the presence of comorbidity. Insufficiency fractures of patellae can be an insidious condition in elderly people. Prepatellar pain, a common symptom in the relapse phase of degenerative arthritis of the knee, should not be underestimated, particularly in patients with diseases influencing metabolism of bone and with an elevated risk of fall. A periodical clinical and instrumental follow up should be done in these patient. Moreover, we underline the necessity of a multidisciplinary approach.

  4. [Fractures of the humerus head].

    Science.gov (United States)

    Jaeger, M; Izadpanah, K; Maier, D; Reising, K; Strohm, P C; Südkamp, N P

    2012-03-01

    Fractures of the proximal humerus are commonly seen especially in the elderly population. High-energy trauma in young people can be distinguished from low-energy trauma in the elderly resulting from falls of a low height which are typically characterized by osteoporosis. A precise analysis of fractures is essential for a good understanding of the fracture and an individual therapy for which the LEGO-Codman classification provided by Hertel is recommended. Nonsurgical therapy is commonly performed and widely accepted not only for simple fractures. For osteosynthesis angular stable implants became the gold standard but are frequently associated with a high rate of complications some of which can be lowered by an improved surgical technique. Even today varus dislocated fractures are challenging, especially in combination with destruction of the medial column. In those cases where stable osteosynthesis can no longer be achieved arthroplasty is indicated. The clinical results of anatomic fracture arthroplasty are strongly related with correct ingrowth of the tuberosities. Reverse fracture arthroplasty may be considered but indications should be interpreted with caution and preferably used in patients older than 75 years.

  5. Scapular fractures and concomitant injuries

    Directory of Open Access Journals (Sweden)

    Akaraborworn Osaree

    2012-11-01

    Full Text Available 【Abstract】 Objective: The association of scapular fractures with other life-threatening injuries including blunt thoracic aortic injury is widely recognized. Few studies have investigated this presumed association. In this study, we investigated the incidence of significant associated injuries with scapular fracture and their outcomes. Methods: A retrospective study was conducted from 2005 to 2009 in a level I trauma center in Thailand. All blunt trauma patients were identified. Patients’ demographics, injury mechanism, associated injuries, Injury Severity Score (ISS, and survival outcomes were recorded. The manage-ment of associated injuries with scapular fracture was reviewed, and the risk factors for mortality were identified. Results: Among the 7 345 trauma patients admitted, scapular fractures occurred in 84 cases (1.1%. The mean age was (37.98±15.21 years. Motorcycle crash was the most fre-quent mechanism of injury, occurring in 51 cases (60.7%. Seventy-four patients (88.1% suffering from scapular frac-tures had associated injuries: 5 (6.0% had significant chest injuries, but none of them had blunt thoracic aortic injury. Two patients (2.4% with scapular fractures died. Factors determining the likelihood of mortality were: (1 ISS>25 (LR=8.5, P<0.05; (2 significant associated chest injury (AIS>3, LR=5.3, P<0.05 and (3 significant associated ab-dominal injury (AIS>3, LR=5.3, P<0.05. Conclusion: A blunt scapular fracture may not accom-pany a blunt thoracic aortic injury but it is strongly related to other injuries like chest injury, extremity injury, head injury, etc. If a scapular fracture is found with a high ISS score, high chest or abdomen AIS score, the patient would have a high risk of mortality. Key words: Aortic rupture; Shoulder fractures; Mul-tiple trauma; Mortality

  6. Possible factors for ankle fractures

    Directory of Open Access Journals (Sweden)

    Tabaković Dejan

    2010-01-01

    Full Text Available Background/Aim. Classification of ankle fractures is commonly used for selecting an appropriate treatment and prognosing an outcome of definite management. One of the most used classifications is the Danis-Weber classification. To the best of our knowledge, in the available literature, there are no parameters affecting specific types of ankle fractures according to the Danis-Weber classification. The aim of this study was to analyze the correlation of the following parameters: age, body weight, body mass index (BMI, height, osteoporosis, osteopenia and physical exercises with specific types of ankle fractures using the Danis-Weber classification. Methods. A total of 85 patients grouped by the Danis-Weber classification fracture types were analyzed and the significance of certain parameters for specific types of ankle fractures was established. Results. The proportion of females was significantly higher (p < 0.001 with a significantly higher age (59.9 years, SD ± 14.2 in relation to males (45.1 years, SD ± 12.8 (p < 0.0001. Type A fracture was most frequent in the younger patients (34.2 years, SD ± 8.6, and those with increased physical exercises (p = 0.020. In type B fracture, the risk factor was osteoporosis (p = 0.0180, while in type C fracture, body weight (p = 0.017 and osteoporosis (p = 0.004 were significant parameters. Conclusion. Statistical analysis using the Danis-Weber classification reveals that there are certain parameters suggesting significant risk factors for specific types of ankle fractures.

  7. XFEM-Based CZM for the Simulation of 3D Multiple-Cluster Hydraulic Fracturing in Quasi-Brittle Shale Formations

    Science.gov (United States)

    Haddad, Mahdi; Sepehrnoori, Kamy

    2016-12-01

    The cohesive zone model (CZM) honors the softening effects and plastic zone at the fracture tip in a quasi-brittle rock, e.g., shale, which results in a more precise fracture geometry and pumping pressure compared to those from linear elastic fracture mechanics. Nevertheless, this model, namely the planar CZM, assumes a predefined surface on which the fractures propagate and therefore restricts the fracture propagation direction. Notably, this direction depends on the stress interactions between closely spaced fractures and can be acquired by integrating CZM as the segmental contact interaction model with a fully coupled pore pressure-displacement model based on extended finite element method (XFEM). This integrated model, called XFEM-based CZM, simulates the fracture initiation and propagation along an arbitrary, solution-dependent path. In this work, we modeled a single stage of 3D hydraulic fracturing initiating from three perforation clusters in a single-layer, quasi-brittle shale formation using planar CZM and XFEM-based CZM including slit flow and poroelasticity for fracture and matrix spaces, respectively, in Abaqus. We restricted the XFEM enrichment zones to the stimulation regions as enriching the whole domain leads to extremely high computational expenses and unrealistic fracture growths around sharp edges. Moreover, we validated our numerical technique by comparing the solution for a single fracture with KGD solution and demonstrated several precautionary measures in using XFEM in Abaqus for faster solution convergence, for instance the initial fracture length and mesh refinement. We demonstrated the significance of the injection rate and stress contrast in fracture aperture, injection pressure, and the propagation direction. Moreover, we showed the effect of the stress distribution on fracture propagation direction comparing the triple-cluster fracturing results from planar CZM with those from XFEM-based CZM. We found that the stress shadowing effect of

  8. Associated injuries in traumatic sternal fractures: a review of the National Trauma Data Bank.

    Science.gov (United States)

    Oyetunji, Tolulope A; Jackson, Hope T; Obirieze, Augustine C; Moore, Danier; Branche, Marc J; Greene, Wendy R; Cornwell, Edward E; Siram, Suryanarayana M

    2013-07-01

    Sternal fractures occur infrequently with blunt force trauma. The demographics and epidemiology of associated injuries have not been well characterized from a national trauma database. The National Trauma Data Bank was queried for patients with closed sternal fractures. The demographics were analyzed by age, gender, mechanism and indicators of anatomic and physiologic injuries. Types of commonly associated injuries were also determined. A total of 23,985 records were analyzed. Males accounted for 68.3 per cent and whites 70.9 per cent. Motor vehicle crash was the leading mechanism. More than 56 per cent had severe injuries based on Injury Severity Score (greater than 15) and 17 per cent with Glasgow Coma Score 8 or less. Crude mortality was 7.9 per cent. The majority (57.8%) and approximately one-third (33.7%) of the patients had rib fractures and lung contusions, respectively, 22.0 per cent with closed pneumothorax, 21.6 per cent had a closed thoracic vertebra fracture, 16.9 per cent with lumbar spine fracture, 3.9 per cent with concussion, and blunt cardiac injury in 3.6 per cent. Sternal fractures are usually associated with severe blunt trauma. Lung contusion remains the leading associated injury followed by vertebral spine fractures. Cardiac injuries are less frequent and vascular injuries less so. Mechanism of injury and presence of sternal fractures should alert providers to these potential associated injuries.

  9. Effect of stress sensitivity on displacement efficiency in CO2 flooding for fractured low permeability reservoirs

    Institute of Scientific and Technical Information of China (English)

    Wang Rui; Yue Xiangan; Zhao Renbao; Yan Pingxiang; Dave Freeman

    2009-01-01

    Carbon dioxide flooding is an effective means of enhanced oil recovery for low permeability reservoirs. If fractures are present in the reservoir, CO2 may flow along the fractures, resulting in low gas displacement efficiency. Reservoir pore pressure will fluctuate to some extent during a CO2 flood, causing a change in effective confining pressure. The result is rock deformation and a reduction in permeability with the reduction in fracture permeability, causing increased flow resistance in the fracture space. Simultaneously, gas cross flowing along the fractures is partially restrained. In this work, the effect of stress changes on permeability was studied through a series of flow experiments. The change in the flowrate distribution in a matrix block and contained fracture with an increase in effective pressure were analyzed. The results lead to an implicit comparison which shows that permeability of fractured core decreases sharply with an increase in effective confining pressure. The fracture flowrate ratio declines and the matrix flowrate ratio increases. Fracture flow will partially divert to the matrix block with the increase in effective confining pressure, improving gas displacement efficiency.

  10. Etiology, diagnosis, and characteristics of facial fracture at a midwestern level I trauma center.

    Science.gov (United States)

    Smith, Hayden; Peek-Asa, Corinne; Nesheim, Dustin; Nish, Andrew; Normandin, Pamela; Sahr, Sheryl

    2012-01-01

    Study purpose was to describe facial fracture frequency, demography, injury characteristics, and diagnostic modalities at a Midwestern level I trauma center. A retrospective review was conducted on a Midwestern trauma center registry for years 2008 and 2009. Patient and injury data were collected along with diagnostic modality for facial fracture patients. Comparative statistics were conducted on the basis of the number of facial fractures, route of admission, presence of traumatic brain injury, and gender. There were 154 patients diagnosed with 443 facial fractures, representing 5% of the trauma population. Median patient age was 45 years. Median number of fractures was 2. Fractures were frequently present in orbit (32%), malar bone and maxilla (26%), and the nasal bones (19%). Motor vehicle crash was the most common mechanism (47%). Most fractures were diagnosed with maxillofacial computed tomography (78%). Males had an odds ratio of 2.5 (95% confidence interval, 1.15-5.43) for multiple facial fractures and composed 67% of the sample. Traumatic brain injury was diagnosed in 71% of patients. This study of a medium-sized city and its surrounding rural areas revealed differences from studies in large urban centers. Differences included lower gender ratio, older average age, and mechanism of injury. While urban trauma centers report assault as a leading cause of facial fracture, this study noted higher frequencies of motor vehicle crash and falls and fewer assaults.

  11. Age-specific incidence of hip fracture in the elderly: a healthy decline.

    LENUS (Irish Health Repository)

    Green, C

    2012-02-01

    Hip fractures in the elderly are an important source of morbidity and mortality. The predicted increase in the number of hip fractures due to the increasing elderly population has not been universally observed. The purpose of this study was to examine the incidence of hip fractures over a twenty year period to determine if this rise is occurring in our region. All hip fractures from the unit over 20 years were identified. Population data for those over 65 in the catchment area of our hospital was acquired. The rate of fractures occurring each year relative to the population was determined. The results were split into age groups. There was a strong correlation between the population rise and number of fractures (p = 0.77). But there was no significant difference in the rate of fracture over time (p = 0.41). However, the average age at which fracture occurred increased by two years. In addition we show the overall trend in the rate of fractures decreases in the younger age groups and increases in the older age groups. Therefore, the predicted rapid increase in rate is not occurring. This probably reflects the strengthening of the economy in Ireland from the 1930\\'s onwards, leading to a healthier population.

  12. Anatomical Variance in Acetabular Anteversion Does Not Predict Hip Fracture Patterns in the Elderly: A Retrospective Study in 135 Patients

    OpenAIRE

    Kamath, Megan Y.; Coleman, Nathan W.; Belkoff, Stephen M.; Mears, Simon C.

    2011-01-01

    It has been suggested that variances in the anatomy of the acetabulum determine the type of hip fracture in elderly patients. Based on this concept, an overly anteverted acetabulum would lead to impingement of the femoral neck against the posterior rim of the acetabulum, causing a femoral neck fracture, whereas with a retroverted acetabulum, external rotation of the hip would be limited by the capsular tissues attached to the trochanteric region, causing a trochanteric fracture. To test the h...

  13. Fracture Union in Closed Interlocking Nail in Humeral Shaft Fractures

    Directory of Open Access Journals (Sweden)

    Ramji Lal Sahu

    2015-01-01

    Conclusions: The results of the present study indicates that in the presence of proper indications, reamed antegrade intramedullary interlocked nailing appears to be a method of choice for internal fixation of osteoporotic and pathologic fractures.

  14. Operative strategy of acetabular fractures

    Institute of Scientific and Technical Information of China (English)

    WANG Yan; TANG Pei-fu; HUANG Peng

    2006-01-01

    Anatomic structure of acetabular fractures are complex and operative exposure and fixation are extremely difficult.For those obviously displaced acetabular fractures, close reduction is doomed to cause deformative healing. Open reduction with internal fixation (ORIF) not only results in anatomic reduction, but also brings complications. No matter which method will be adopted, traumatic arthritis or avascular necrosis of femoral head might occur. In order to treat acetabular fractures more effectively, orthopedic surgeons should be required to fully master the acetabular anatomy, biomechanics, classification and the necessary knowledge for complication prevention.

  15. Insufficiency fracture after radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Dong Ryul; Huh, Seung Jae [Dept.of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2014-12-15

    Insufficiency fracture occurs when normal or physiological stress applied to weakened bone with demineralization and decreased elastic resistance. Recently, many studies reported the development of IF after radiation therapy (RT) in gynecological cancer, prostate cancer, anal cancer and rectal cancer. The RT-induced insufficiency fracture is a common complication during the follow-up using modern imaging studies. The clinical suspicion and knowledge the characteristic imaging patterns of insufficiency fracture is essential to differentiate it from metastatic bone lesions, because it sometimes cause severe pain, and it may be confused with bone metastasis.

  16. Treatment of Unstable Ankle Fractures

    Directory of Open Access Journals (Sweden)

    Yaniel Truffín Rodríguez

    2015-11-01

    Full Text Available Patients with unstable ankle fractures frequently attend the emergency rooms. It is estimated that there are 122 ankle fractures per 100 000 people a year. Surgical treatment of those that are unstable is inevitable since they can not be corrected in a conservative way. Several surgical procedures for repair of such lesions have been described and all of them constitute important tools for the orthopedic surgeon. Therefore, we conducted a literature review to discuss the current management of unstable ankle fractures based on the analysis of the published literature and the experiences in the Dr. Gustavo Aldereguía Lima University General Hospital of Cienfuegos.

  17. Sternal fractures and their management

    Directory of Open Access Journals (Sweden)

    Al-achraf Khoriati

    2013-01-01

    Full Text Available Sternal fractures are predominantly associated with deceleration injuries and blunt anterior chest trauma. Sternal trauma must be carefully evaluated by monitoring of vital parameters and it is of paramount importance that concomitant injuries are excluded. Nevertheless, routine admission of patients with isolated sternal fractures for observation is still common in today′s practice, which is often unnecessary. This article aims to describe the prognosis, the recommended assessment and management of patients with sternal fractures, to help clinicians make an evidence-based judgment regarding the need for hospitalization.

  18. Interacting Cracks in an Environmentally Assisted Fracture

    Science.gov (United States)

    Levandovsky, Artem; Balazs, Anna

    2006-03-01

    We perform the study of environmentally assisted fracture within the framework of a lattice model. Formation of an ensemble of environmentally assisted microcracks, their coalescence and formation of crack ``avalanches'' lead to a very rich dynamical picture. Under specific condition crack healing can occur due to cohesive forces, which hold material together and tend to pull atoms together even if they are separated by a crack over several lattice units. We investigate the dynamical interplay between crack formation, arrest, healing and re-cracking. The goal here is to provide an understanding of the conditions leading to the phenomena of crack healing that happens along with the crack formation. We study the morphology of crack patterns with the intentions to establish a way to enhance the healing property of a material sample.

  19. Lead and the Romans

    Science.gov (United States)

    Reddy, Aravind; Braun, Charles L.

    2010-01-01

    Lead poisoning has been a problem since early history and continues into modern times. An appealing characteristic of lead is that many lead salts are sweet. In the absence of cane and beet sugars, early Romans used "sugar of lead" (lead acetate) to sweeten desserts, fruits, and sour wine. People most at risk would have been those who…

  20. Lead and the Romans

    Science.gov (United States)

    Reddy, Aravind; Braun, Charles L.

    2010-01-01

    Lead poisoning has been a problem since early history and continues into modern times. An appealing characteristic of lead is that many lead salts are sweet. In the absence of cane and beet sugars, early Romans used "sugar of lead" (lead acetate) to sweeten desserts, fruits, and sour wine. People most at risk would have been those who consumed the…

  1. Prediction of Ductile Fracture Surface Roughness Scaling

    DEFF Research Database (Denmark)

    Needleman, Alan; Tvergaard, Viggo; Bouchaud, Elisabeth

    2012-01-01

    Experimental observations have shown that the roughness of fracture surfaces exhibit certain characteristic scaling properties. Here, calculations are carried out to explore the extent to which a ductile damage/fracture constitutive relation can be used to model fracture surface roughness scaling....... The scaling properties of the predicted thickness average fracture surfaces are calculated and the results are discussed in light of experimental observations....

  2. Atypical fractures on long term bisphosphonates therapy.

    LENUS (Irish Health Repository)

    Hussein, W

    2011-01-01

    Bisphosphonates reduce fractures risk in patients with osteoporosis. A new pattern of fractures is now being noted in patients on prolonged bisphosphonate therapy. We report a case of an atypical femoral fracture with preceding pain and highlight the characteristics of these fractures.

  3. Scale-Dependent Fracture-Matrix Interactions And Their Impact on Radionuclide Transport - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Detwiler, Russell

    2014-06-30

    coefficients obtained from tracer tests highlights this point and suggests that the underlying mechanisms and relationship between rock and fracture properties are not fully understood in large complex fracture networks. In this project, we developed a high-resolution DFN model of solute transport in fracture networks to explore and quantify the mechanisms that control transport in complex fracture networks and how these may give rise to observed scale-dependent matrix diffusion coefficients. Results demonstrate that small scale heterogeneity in the flow field caused by local aperture variability within individual fractures can lead to long-tailed breakthrough curves indicative of matrix diffusion, even in the absence of interactions with the fracture matrix. Furthermore, the temporal and spatial scale dependence of these processes highlights the inability of short-term tracer tests to estimate transport parameters that will control long-term fate and transport of contaminants in fractured aquifers.

  4. A New Physics-Based Modeling of Multiple Non-Planar Hydraulic Fractures Propagation

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jing [University of Utah; Huang, Hai [Idaho National Lab. (INL), Idaho Falls, ID (United States); Deo, Milind [University of Utah; Jiang, Shu [Energy & Geoscience Institute

    2015-10-01

    Because of the low permeability in shale plays, closely spaced hydraulic fractures and multilateral horizontal wells are generally required to improve production. Therefore, understanding the potential fracture interaction and stress evolution is critical in optimizing fracture/well design and completion strategy in multi-stage horizontal wells. In this paper, a novel fully coupled reservoir flow and geomechanics model based on the dual-lattice system is developed to simulate multiple non-planar fractures propagation. The numerical model from Discrete Element Method (DEM) is used to simulate the mechanics of fracture propagations and interactions, while a conjugate irregular lattice network is generated to represent fluid flow in both fractures and formation. The fluid flow in the formation is controlled by Darcy’s law, but within fractures it is simulated by using cubic law for laminar flow through parallel plates. Initiation, growth and coalescence of the microcracks will lead to the generation of macroscopic fractures, which is explicitly mimicked by failure and removal of bonds between particles from the discrete element network. We investigate the fracture propagation path in both homogeneous and heterogeneous reservoirs using the simulator developed. Stress shadow caused by the transverse fracture will change the orientation of principal stress in the fracture neighborhood, which may inhibit or alter the growth direction of nearby fracture clusters. However, the initial in-situ stress anisotropy often helps overcome this phenomenon. Under large in-situ stress anisotropy, the hydraulic fractures are more likely to propagate in a direction that is perpendicular to the minimum horizontal stress. Under small in-situ stress anisotropy, there is a greater chance for fractures from nearby clusters to merge with each other. Then, we examine the differences in fracture geometry caused by fracturing in cemented or uncemented wellbore. Moreover, the impact of

  5. Ligamentotaxis for comminuted fracture of capitate:a case report

    Institute of Scientific and Technical Information of China (English)

    Ashok Kumar; Mohammed Tahir Ansan; Chander Shekhar Yadav; Laxman Rijal

    2012-01-01

    We present the technical report for treatment of comminuted fracture of the capitate with ligamentotaxis.The base of third metacarpal was found to be fractured with comminution of the capitate.The decrease in carpal height index and comminution of the third metacarpal base lead to dilemma between conservative treatment and surgical management of this particular injury.The surgical management was chosen to maintain the carpal height index of the wrist to prevent the late degenerative changes.The patient was applied with external fixator in distraction mode expanning the wrist joint for six weeks,and the wrist was mobilised after removal of the fixator.It is shown that the external fixator in distraction mode expanning the wrist joint is a good alternative method for treatment of capitate fracture.

  6. Pregnancy-associated osteoporosis presenting severe vertebral fractures.

    Science.gov (United States)

    Ozturk, Cihat; Atamaz, Funda Calis; Akkurt, Halil; Akkoc, Yesim

    2014-01-01

    The syndrome of pregnancy-associated osteoporosis (PAO) is a rare disorder which occurs either in late pregnancy or early post-partum period leading to fragility fracture(s), most commonly in the vertebral bodies. We presented two cases with PAO who had compression fractures at multiple levels involving five vertebrae in one case and 10 vertebrae in the other. Their spinal bone mineral density values were below -2.5 standard deviations. Anti-osteoporotic treatments with nasal calcitonin 400 IU/day, vitamin D 300.000 IU single dose, calcium 1000 mg/day, vitamin D 880 IU/day were initiated. In one case, kyphoplasty was performed by a spinal surgeon. In addition to a thoracolumbosacral orthosis, a rehabilitation program including muscle strengthening, range of motion, relaxation and weight-bearing exercises was started for both cases. These cases emphasize that all pregnant women with complaints of back/lumbar pain should be carefully evaluated.

  7. Multiple teeth fractures in dentinogenesis imperfecta: a case report.

    Science.gov (United States)

    Min, Boram; Song, Je Seon; Lee, Jae-Ho; Choi, Byung-Jai; Kim, Kwang-Mahn; Kim, Seong-Oh

    2014-01-01

    Dentinogenesis imperfecta (DGI) is a hereditary defect consisting of opalescent teeth composed of irregularly formed and hypomineralized dentin. This paper presents the multiple fractures of DGI-affected teeth and suggests the reason of low fracture resistance by observing the dentin microstructures directly using scanning electron microscope (SEM) and by measuring its surface hardness using the Vickers hardness test. SEM revealed that while the enamel microstructure was similar in the DGI-affected and normal teeth, the microstructure of the DGI-affected dentin was poorly woven and more loosely packed than that of the normal dentin. The Vickers hardness of the DGI-affected dentin was 4.89 times softer than the normal dentin. The low fracture resistance of DGI-affected teeth can be attributed to the poorly woven microstructure of their dentin, which leads to a reduction in hardness.

  8. Stent Fracture after Everolimus-Eluting Stent Implantation

    Directory of Open Access Journals (Sweden)

    Ali S. Almasood

    2011-01-01

    Full Text Available Compared with bare-metal stents, drug-eluting stents (DES have greatly reduced the risk of in-stent restenosis (ISR by inhibiting neointimal growth. Nevertheless, DES are still prone to device failure, which may lead to cardiac events. Recently, stent fracture (SF has emerged as a potential mechanism of DES failure that is associated with ISR. Stent fracture is strongly related to stent type, and prior reports suggest that deployment of sirolimus eluting stents (SES may be associated with a higher risk of SF compared to other DES. Everolimus eluting stents (EESs represent a new generation of DES with promising results. The occurrence of SF with EES has not been well established. The present paper describes two cases of EES fracture associated with ISR.

  9. Impacts of transient heat transfer modeling on prediction of advanced cladding fracture during LWR LBLOCA

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youho, E-mail: euo@kaist.ac.kr; Lee, Jeong Ik, E-mail: jeongiklee@kaist.ac.kr; NO, Hee Cheon, E-mail: hcno@kaist.ac.kr

    2016-03-15

    Highlights: • Use of constant heat transfer coefficient for fracture analysis is not sound. • On-time heat transfer coefficient should be used for thermal fracture prediction. • ∼90% of the actual fracture stresses were predicted with the on-time transient h. • Thermal-hydraulic codes can be used to better predict brittle cladding fracture. • Effects of surface oxides on thermal shock fracture should be accounted by h. - Abstract: This study presents the importance of coherency in modeling thermal-hydraulics and mechanical behavior of a solid for an advanced prediction of cladding thermal shock fracture. In water quenching, a solid experiences dynamic heat transfer rate evolutions with phase changes of the fluid over a short quenching period. Yet, such a dynamic change of heat transfer rates has been overlooked in the analysis of thermal shock fracture. In this study, we are presenting quantitative evidence against the prevailing use of a constant heat transfer coefficient for thermal shock fracture analysis in water. We conclude that no single constant heat transfer could suffice to depict the actual stress evolution subject to dynamic fluid phase changes. Use of the surface temperature dependent heat transfer coefficient will remarkably increase predictability of thermal shock fracture of brittle materials. The presented results show a remarkable stress prediction improvement up to 80–90% of the actual stress with the use of the surface temperature dependent heat transfer coefficient. For thermal shock fracture analysis of brittle fuel cladding such as oxidized zirconium-based alloy or silicon carbide during LWR reflood, transient subchannel heat transfer coefficients obtained from a thermal-hydraulics code should be used as input for stress analysis. Such efforts will lead to a fundamental improvement in thermal shock fracture predictability over the current experimental empiricism for cladding fracture analysis during reflood.

  10. Hip fracture epidemiological trends, outcomes, and risk factors, 1970–2009

    Directory of Open Access Journals (Sweden)

    Ray Marks

    2009-12-01

    Full Text Available Ray MarksCity University of New York and Columbia University, New York, NY, USAAbstract: Hip fractures – which commonly lead to premature death, high rates of morbidity, or reduced life quality – have been the target of a voluminous amount of research for many years. But has the lifetime risk of incurring a hip fracture decreased sufficiently over the last decade or are high numbers of incident cases continuing to prevail, despite a large body of knowledge and a variety of contemporary preventive and refined surgical approaches? This review examines the extensive hip fracture literature published in the English language between 1980 and 2009 concerning hip fracture prevalence trends, and injury mechanisms. It also highlights the contemporary data concerning the personal and economic impact of the injury, plus potentially remediable risk factors underpinning the injury and ensuing disability. The goal was to examine if there is a continuing need to elucidate upon intervention points that might minimize the risk of incurring a hip fracture and its attendant consequences. Based on this information, it appears hip fractures remain a serious global health issue, despite some declines in the incidence rate of hip fractures among some women. Research also shows widespread regional, ethnic and diagnostic variations in hip fracture incidence trends. Key determinants of hip fractures include age, osteoporosis, and falls, but some determinants such as socioeconomic status, have not been well explored. It is concluded that while more research is needed, well-designed primary, secondary, and tertiary preventive efforts applied in both affluent as well as developing countries are desirable to reduce the present and future burden associated with hip fracture injuries. In this context, and in recognition of the considerable variation in manifestation and distribution, as well as risk factors underpinning hip fractures, well-crafted comprehensive, rather

  11. Routine functional assessment for hip fracture patients

    DEFF Research Database (Denmark)

    Pedersen, Tonny J; Lauritsen, Jens M

    2016-01-01

    Background and purpose - Pre-fracture functional level has been shown to be a consistent predictor of rehabilitation outcomes in older hip fracture patients. We validated 4 overall pre-fracture functional level assessment instruments in patients aged 65 or more, used the prediction of outcome at 4...... months post-fracture, and assessed cutoff values for decision making in treatment and rehabilitation. Patients and methods - 165 consecutive patients with acute primary hip fracture were prospectively included in the study. Pre-fracture Barthel-20, Barthel-100, cumulated ambulation score, and new...... investigation of usage for guidance of clinical and rehabilitation decisions concerning hip fracture patients is warranted....

  12. Transverse posterior element fractures associated with torsion

    Energy Technology Data Exchange (ETDEWEB)

    Abel, M.S.

    1989-01-01

    Six examples of a previously undescribed class of transverse vertebral element fractures are presented. These fractures differ from Chance and Smith fractures and their variants in the following respects: (1) the etiology is torsion and not flexion; (2) there is neither distraction of posterior ring fragments nor posterior ligament tears; (3) in contrast to Chance and Smith fractures, extension of the fracture into the vertebral body is absent or minimal; (4) the transverse process of the lumbar vertebra is avulsed at its base with a vertical fracture, not split horizontally. These fractures occur in cervical, lumbar, and sacral vertebrae in normal or compromised areas of the spine.

  13. Coupled Fracture and Flow in Shale in Hydraulic Fracturing

    Science.gov (United States)

    Carey, J. W.; Mori, H.; Viswanathan, H.

    2014-12-01

    Production of hydrocarbon from shale requires creation and maintenance of fracture permeability in an otherwise impermeable shale matrix. In this study, we use a combination of triaxial coreflood experiments and x-ray tomography characterization to investigate the fracture-permeability behavior of Utica shale at in situ reservoir conditions (25-50 oC and 35-120 bars). Initially impermeable shale core was placed between flat anvils (compression) or between split anvils (pure shear) and loaded until failure in the triaxial device. Permeability was monitored continuously during this process. Significant deformation (>1%) was required to generate a transmissive fracture system. Permeability generally peaked at the point of a distinct failure event and then dropped by a factor of 2-6 when the system returned to hydrostatic failure. Permeability was very small in compression experiments (conformed to Forscheimer's law. The coupled deformation and flow behavior of Utica shale, particularly the large deformation required to initiate flow, indicates the probable importance of activation of existing fractures in hydraulic fracturing and that these fractures can have adequate permeability for the production of hydrocarbon.

  14. Heterogeneous alternation of fractured rock driven by preferential carbonate dissolution

    Science.gov (United States)

    Wen, H.; Zhi, W.; Li, L.

    2016-12-01

    Understanding the alternation of fractured rock induced by geochemical reactions is critical for predicting the flow, solute transport and energy production in geosystems. Most existing studies on fracture alterations focus on rocks with single minerals where reactions occur at the fracture wall resulting in fracture aperture alteration while ignoring rock matrix properties (e.g. the formation and development of altered zones). In this work, we aimed to mechanistically understand the role of preferential calcite dissolution in the long-term evolution of fracture and rock matrix. We use direct simulation of physics-based reactive transport processes in an image of fractured rock at the resolution of tens of micrometers. Three numerical experiments were carried out with the same initial physical properties however different calcite content. Simulation results show that the formation and development of altered zones in the rock matrix is highly related to the abundance of fast-dissolving calcite. Abundant calcite (50% (v/v), calcite50) leads to a localized, thick zone of large porosity increase while low calcite content (10% (v/v), calcite10) creates an extended and narrow zone of small porosity increase resulting in surprisingly larger change in effective transport property. After 300 days of dissolution, although with relatively similar dissolved calcite mass and matrix porosity increase, effective matrix diffusion coefficients increase by 9.9 and 19.6 times in calcite50 and calcite10, respectively. In turn, calcite dissolution rates are directly limited by diffusive transport in the altered matrix and the shape of the altered zone. This work sheds light on the unique characteristics of reactive transport in fractured, mineralogically complex rocks that are different from those with single minerals (Wen et al., 2016). Reference: Wen, H., Li, L., Crandall, D. and Hakala, J.A. (2016) Where Lower Calcite Abundance Creates More Alteration: Enhanced Rock Matrix

  15. Fracture Resistance of Roots after Application of Different Sealers

    Science.gov (United States)

    Dibaji, Fatemeh; Afkhami, Farzaneh; Bidkhori, Babak; Kharazifard, Mohammad Javad

    2017-01-01

    Introduction: Vertical root fracture inevitably leads to tooth extraction. Thus, root filling with obturating materials and sealers that can reinforce the tooth would be an ideal way to reduce fracture in root treated teeth. This study aimed to assess the fracture resistance of roots following the application of different sealers including Epiphany, iRoot sealer and AH-plus. Methods and Materials: Fifty extracted human single-canal premolars without caries, curvature or cracks were used in this study. Tooth crowns were cut to yield 13-mm-long roots. Five roots were put in the negative control group and were left unprepared. Forty-five canals were prepared using ProTaper rotary files up to F3 and were then randomly divided into three groups based on the sealer type (n=15). The root canals were filled using cold lateral condensation technique with gutta-percha and AH-Plus sealer, gutta-percha and iRoot sealer and Resilon and Epiphany sealer, in groups one to three, respectively. The roots were then mounted in acrylic molds for fracture resistance testing and subjected to compressive load at a crosshead speed of 1mm/min until fracture. Data were analyzed using the one-way ANOVA. Results: The mean fracture resistance was 673.38±170.42 N in AH-Plus, 562.00±184.68 N in iRoot, 708.03±228.05 N in Resilon and 592.59±117.29 N in the control group. No statistically significant difference was found between the experimental groups and the negative control group (P=0.26). Conclusion: Application of AH-Plus, bioceramic and Resilon sealers did not change the fracture resistance of roots compared to that of unprepared root canals. PMID:28179924

  16. Anistotropy and scaling of flow fluctuations in a rough fracture

    Science.gov (United States)

    Neuville, A.; Toussaint, R.; Schmittbuhl, J.

    2009-04-01

    Is there a link between scaling laws characterizing fracture apertures and scaling laws of the velocity of the fluid flowing inside these fractures? A fluid inside a rough fracture is studied in laminar regime on the basis of the Stokes equation, using finite differences. Our model illustrates that the hydraulic flow may significantly differ from the cubic law which is obtained between flat parallel plates: for instance, the fracture roughness potentially induces channeling effects. Our computation is based on a self-affine aperture model, which has been shown to be representative of real-world fractures. However, in practice, for field measurements, it is impossible to know in detail the spatial variability of the geometrical aperture. Therefore, we search for the minimal information about the fracture morphology that is necessary and sufficient to get the right order of the hydraulic fracture permeability and its anisotropy. From several computations with various apertures, we observe that the largest scales of the aperture fluctuations control the hydraulic behavior. This remark leads us to filter the modeled aperture in the Fourier domain to remove the small scale aperture variations. Doing that, we propose an analytical model for the conductivity based on a small set of parameters which brings the right macroscopic transmissivity (within five percent accuracy). This model amounts to computing the flow in an aperture reduced to the only very few Fourier modes. In addition, an analytical expression of the velocity fluctuations in the Fourier domain as a function of the aperture fluctuation is computed, assuming the aperture to be self-affine. It shows that the scaling of the velocity heterogeneities is linked to the scaling of the aperture heterogeneities: the velocity fluctuations are as well self-affine, with the same Hurst exponent, but with a dipolar nature, i.e. with an anisotropic prefactor linked to the macroscopic pressure drop

  17. Subtrochanteric fractures in bisphosphonate-naive patients

    DEFF Research Database (Denmark)

    Adachi, Jonathan D; Lyles, Kenneth; Boonen, Steven

    2011-01-01

    Our purpose was to characterize the risks of osteoporosis-related subtrochanteric fractures in bisphosphonate-naive individuals. Baseline characteristics of patients enrolled in the HORIZON-Recurrent Fracture Trial with a study-qualifying hip fracture were examined, comparing those who sustained...... incident subtrochanteric fractures with those sustaining other hip fractures. Subjects were bisphosphonate-naive or had a bisphosphonate washout period of 6-24 months and subsequently received an annual infusion of zoledronic acid 5 mg or placebo after low-trauma hip-fracture repair. In total, 2,127 men...... and women were included. Of the qualifying hip fractures, 5.2% were subtrochanteric, 54.8% femoral neck, 33.0% intertrochanteric, and 7.1% other (generally complex fractures of mixed type). Significant baseline (pre-hip fracture) differences were seen between index hip-fracture types, with the percentage...

  18. Jinde Lead lead smelting project starts construction

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>On Dec.20,the lead smelting project of Jiangxi Jinde Lead started construction in Dexin as a technical renovation project on environmental treatment of Jiangxi Metallurgical Group.The project is the one with the largest investment of Provincial Metallurgical Group in non-ferrous

  19. Compression fractures of the back

    Science.gov (United States)

    Taking steps to prevent and treat osteoporosis is the most effective way to prevent compression or insufficiency fractures. Getting regular load-bearing exercise (such as walking) can help you avoid bone loss.

  20. FRACTURE OF AMORPHOUS BILAYER RIBBON

    NARCIS (Netherlands)

    Ocelik, Vaclav; DUHAJ, P; CSACH, K; MISKUF, J; BENGUS, VZ

    On the basis of measuring the mechanical properties and observing the fracture surface of an amorphous bilayer ribbon some partial conclusions on the mechanical quality of the bimetal boundary were drawn.

  1. Fracture risk assessed by Fracture Risk Assessment Tool (FRAX) compared with fracture risk derived from population fracture rates

    DEFF Research Database (Denmark)

    Rubin, Katrine Hass; Abrahamsen, Bo; Hermann, Anne Pernille

    2011-01-01

    Purpose: To evaluate the performance of the Swedish version of Fracture Risk Assessment Tool (FRAX)) without bone mass density (BMD) in a Danish population to examine the possibility of applying this version to Danish women. METHODS: From the Danish National Register of social security numbers, we...... randomly selected 5000 women living in the region of Southern Denmark aged 40-90 years to receive a mailed questionnaire concerning risk factors for osteoporosis based on FRAX. The predicted 10-year probability of hip fractures was calculated for each woman returning a complete questionnaire using...... the Swedish version of FRAX. The observed 10-year hip fracture risk was also calculated for each woman using age-specific hip fracture rates from the National Hospital Discharge Register and National survival tables. RESULTS: A total of 4194 (84%) women responded to the questionnaire and 3636 (73%) gave...

  2. Ankle Fractures Often Not Diagnosed

    Science.gov (United States)

    ... injuries. Telltale signs of a fracture include bruising, blisters, significant swelling or bone protruding through the skin. ... for stability. She also advises buying from small shoe stores that have certified orthotists who work with ...

  3. Principles of Hand Fracture Management

    Science.gov (United States)

    Haughton, DN; Jordan, D; Malahias, M; Hindocha, S; Khan, W

    2012-01-01

    The hand is essential in humans for physical manipulation of their surrounding environment. Allowing the ability to grasp, and differentiated from other animals by an opposing thumb, the main functions include both fine and gross motor skills as well as being a key tool for sensing and understanding the immediate surroundings of their owner. Hand fractures are the most common fractures presenting at both accident and emergency and within orthopaedic clinics. Appropriate evaluation at first presentation, as well as during their management, can significantly prevent both morbidity and disability to a patient. These decisions are dependant on a wide range of factors including age, hand dominance, occupation and co-morbidities. A fracture is best described as a soft tissue injury with an associated bony injury. Despite this being the case, this paper intends to deal mainly with the bone injury and aims to discuss both the timing, as well as the methods available, of hand fracture management. PMID:22423303

  4. The treatment of subtrochanteric fractures

    Directory of Open Access Journals (Sweden)

    Vučetić Čedomir S.

    2011-01-01

    Full Text Available Subtrochanteric fractures of the femur have a special place because of a significant number of complications following treatment. Powerful loading forces asymmetrically acting to this bone segment, as well as poor vascularization interfere with bone union. There are basically two current approaches in the fixation of subtrochanteric fractures; the first involves a plate with a compression screw and another one is intramedullary (IM nail, with two options: centromedullary (standard interlocking femoral nail and cephalomedullary femoral nail with two modifications, reconstructive and trochanteric. All IM nails may be used by open technique or closed minimal invasive method. IM nailing is favoured in view of a shorter operative time, shorter hospitalisation and complications. Indirect fracture reduction and knowledge of biology of bone fracture may result in full success without any bone graft.

  5. Fractura bronquial BRONCHIAL FRACTURE

    Directory of Open Access Journals (Sweden)

    IVÁN CAVIEDES S

    2003-04-01

    Full Text Available El traumatismo torácico es una entidad patológica emergente, relacionada con accidentes automovilísticos. La lesión más frecuente es la fractura costal. Dependiendo de su gravedad, éste puede provocar tórax volante, contusión cardíaca, lesiones vasculares u otras alteraciones. La ruptura bronquial se observa ocasionalmente en traumatismos torácicos cerrados, y por lo general tiene lugar en el tronco principal del árbol tráqueo-bronquial. Su diagnóstico y manejo inicial representan un problema mayor. Los signos clásicos son la persistencia de neumotórax y flujo masivo de aire a través del drenaje torácico; sin embargo también hay casos que no son típicos. Es difícil determinar el momento correcto para iniciar la ventilación mecánica con presión positiva, la que puede aumentar gravemente el flujo de aire a través de la ruptura bronquial y acentuar el neumotórax a tensión. Presentamos el caso de un hombre de 25 años con un traumatismo torácico cerrado, causado por un accidente de automóvil, en quien la broncoscopía demostró una fractura del bronquio lobar medio. Comprobamos en este paciente, que la fibrobroncoscopía es el procedimiento más útil tanto en el diagnóstico, como en el tratamiento inicial y en el seguimiento post operatorio de su fractura bronquiaThoracic trauma is an emerging pathology related to the increase of motor vehicle accidents. Rib fracture is the most frequent injury; depending on the severity of the event it may be associated with flail chest, cardiac contusion, vascular lesions and other injuries. Bronchial rupture is occasionally seen in blunt trauma and it occurs mostly in the main stem of the tracheobronchial tree. It represents a great task in diagnosis and initial management. Persistent pneumothorax and massive airflow by the thoracic drain are the classic signs, however other cases are not so typical. The right moment to begin positive pressure ventilation is challenging, because in

  6. Fracture model of radiation blistering

    Energy Technology Data Exchange (ETDEWEB)

    Kamada, K.; Higashida, Y.

    1979-06-01

    The formation process of blisters is interpreted by a fracture model on the basis of the stress fields around a lenticular bubble calculated in a previous paper. This model implicitly presumes a microcrack nucleated at a depth near the projected range of the ions. Two factors are separated theoretically to explain the blister formation: One is a geometrical factor which depends only on the ratio of size to depth, from a free surface, and the other factor is proportional to the square of the ratio between the internal gas pressure of the bubble to plastic yield stress of the target materials, depending entirely on the physical and chemical properties of the materials and gas atoms. The relation between the blister diameter and the cover thickness must be basically linear as expected from the first factor, but is modulated by the second factor, giving a slight departure from linearity as observed by experiment. The ratio of the gas pressure to the yield stress must be 0.02--0.2 in magnitude and depends on the ion energy and the target materials. This value leads to an estimation that the amount of gas atoms contained in the blister is about 10% of the injected ions. Griffith's criterion for the crack propagation in the subsurface layer with taking into account of ductility of the materials near the crack tip was derived, and showed that the estimated internal pressure of the blister is far smaller than the necessary pressure to satisfy the criterion. The objections against the gas-pressure model were criticized on the basis of the present model.

  7. Mode I fracture toughness of coal

    Energy Technology Data Exchange (ETDEWEB)

    Bhagat, R.B.

    1985-10-01

    This investigation was undertaken to determine the fracture toughness and tensile strength of coal and to correlate these with the grindability of the coals in order to understand the fracture mechanics behaviour of coal. Results showed statistical relationships for the dependence of fracture toughness on the tensile strength of coal and between the fracture toughness and the Hardgrove Grindability Index. Softer coals have a lower fracture toughness value as coal is a brittle material. 16 references.

  8. Correlation between porous structure and fracture stress for metallurgical coke

    Energy Technology Data Exchange (ETDEWEB)

    Gardien, J.F.; Lemaire, E.; Dubs, A.; Osmont, P.; Laurent, J.P.; Steiler, J.M. (Institut de Recherches de la Siderurgie Francaise, Maizieres-les-Metz (France))

    1994-05-26

    Various samples of coke have been characterized by diametral compression and the geometry of the porous network has been analysed in terms of fractal structure. It is found that the coke studied exhibits a fractal behaviour on at least two decades. Diametral compression test leads to two different ways of breaking; brittle fracture, and in some cases complex fracture. As expected, the fracture stress is not linked with the fractal dimension in case of brittle fracture, but with the mean size of the largest pores. In case of complex loading conditions, the fracture strength is linked with the fractal dimension. The models of Cook and of Anderson, which integrate fractal description of porous materials in Griffith's theory, do not seem to be valid concerning coke material. The present approach of characterising the porous structure of coke by the fractal dimension seems adapted to explain coke strength, especially under complex stress conditions, but should be extended to an increased number of coke type samples.

  9. Osteoporotic Hip Fractures: The Burden of Fixation Failure

    Directory of Open Access Journals (Sweden)

    J. M. Broderick

    2013-01-01

    Full Text Available Osteoporotic hip fractures are a major cause of morbidity and mortality in the elderly. Furthermore, reduced implant anchorage in osteoporotic bone predisposes towards fixation failure and with an ageing population, even low failure rates represent a significant challenge to healthcare systems. Fixation failure in fragility fractures of the hip ranges from 5% in peritrochanteric fractures through to 15% and 41% in undisplaced and displaced fractures of the femoral neck, respectively. Our findings, in general, support the view that failed internal fixation of these fragility fractures carries a poor prognosis: it leads to a twofold increase in the length of hospital stay and a doubling of healthcare costs. Patients are more likely to suffer a downgrade in their residential status upon discharge with a consequent increase in social dependency. Furthermore, the marked disability and reduction in quality of life evident before salvage procedures may persist at long-term followup. The risk, of course, for the elderly patient with a prolonged period of decreased functioning is that the disability becomes permanent. Despite this, however, no clear link between revision surgery and an increase in mortality has been demonstrated in the literature.

  10. Osteoporotic hip fractures: the burden of fixation failure.

    Science.gov (United States)

    Broderick, J M; Bruce-Brand, R; Stanley, E; Mulhall, K J

    2013-01-01

    Osteoporotic hip fractures are a major cause of morbidity and mortality in the elderly. Furthermore, reduced implant anchorage in osteoporotic bone predisposes towards fixation failure and with an ageing population, even low failure rates represent a significant challenge to healthcare systems. Fixation failure in fragility fractures of the hip ranges from 5% in peritrochanteric fractures through to 15% and 41% in undisplaced and displaced fractures of the femoral neck, respectively. Our findings, in general, support the view that failed internal fixation of these fragility fractures carries a poor prognosis: it leads to a twofold increase in the length of hospital stay and a doubling of healthcare costs. Patients are more likely to suffer a downgrade in their residential status upon discharge with a consequent increase in social dependency. Furthermore, the marked disability and reduction in quality of life evident before salvage procedures may persist at long-term followup. The risk, of course, for the elderly patient with a prolonged period of decreased functioning is that the disability becomes permanent. Despite this, however, no clear link between revision surgery and an increase in mortality has been demonstrated in the literature.

  11. The usefulness of sagittal reformation for diagnosis of sternal fracture

    Energy Technology Data Exchange (ETDEWEB)

    Im, Dong Jin; Hahn, Seok; Kim, Young Ju [Dept. of Radiology, Wonju Severance Christian Hospital, Yonsei University Wonju College of Medicine, Wonju (Korea, Republic of)

    2014-01-15

    The purpose of our study was to evaluate the usefulness of sagittal reformation of chest computed tomography for the diagnosis of sternal fracture after trauma. We retrospectively reviewed medical records and chest computer tomography (CT) of 716 patients in the emergency department after trauma between January and December 2010. Two radiologists investigated chest CT images. We investigated numbers and locations of sternal fractures on axial images only and on both axial and sagittal images for each radiologist. First, radiologist found sternal fractures in 58 patients (70.7%) on only axial images, and 80 (97.5%) on both axial and sagittal images. Second, radiologist found fractures in 67 patients (81.7%) on axial image only and 81 (98.7%) on both axial and sagittal images. The sensitivity increased after adding sagittal reformation images for each radiologist (p < 0.05, respectively). On the axial images, the interobserver agreement was low (k 0.596) between the two radiologists. However, on both axial and sagittal images, the interobserver agreement increased (k = 0.872). Sagittal reformation of chest CT increases the chance of diagnosis for sternal fracture and leads to early diagnosis resulting in appropriate treatment.

  12. Hip resurfacing femoral neck fracture influenced by valgus placement.

    Science.gov (United States)

    Anglin, Carolyn; Masri, Bassam A; Tonetti, Jérôme; Hodgson, Antony J; Greidanus, Nelson V

    2007-12-01

    Femoral neck fracture is the most common short-term concern after hip resurfacing arthroplasty. Currently, there is little basis to decide between neutral and valgus placement. We loaded 10 notched cadaveric femur pairs to failure; one side was implanted at 0 degrees relative to the femoral neck and the other at 10 degrees valgus. All 20 were dual-energy X-ray absorptiometry-scanned. Failure load correlated with bone mineral density. Valgus placement increased the fracture load by an average of 28% over neutral for specimens with normal bone mineral density but had no effect on fracture load in specimens with low bone mineral density. For specimens with normal bone mineral density (typical of patients undergoing resurfacing arthroplasty), neutral-valgus placement had a greater effect than bone mineral density, explaining 54% of the fracture load variance. Component placement greater than 10 degrees valgus is likely undesirable because this can lead to an increase in component size and a greater likelihood of notching. To reduce fracture risk, we recommend placing the femoral component in valgus and selecting patients with higher bone mineral density.

  13. HIGHER VISCOSITY OF LOGWAY FRACTURE FOR WIRE DRAWING

    Directory of Open Access Journals (Sweden)

    V. N. Kovalevsky

    2009-01-01

    Full Text Available The paper presents results of the investigations on evaluation of logway resistance which are used for drawing cord wire made of tungsten-containing hard alloy. It has been shown that complicated loading conditions lead to fracture of a tool surface and these conditions are attributed to the action of various mechanisms: wearing due to high local stresses and deformations, fracture due to stretching stresses at logway expansion, small-cycle fatigue, heat shock etc. It is proposed to evaluate logway serviceability by such indices as hardness, strength and fracture viscosity and an amount of bundle and size of tungsten carbide grain influence on these indices.  As an alternative material to a hard alloy it is advanced to use a diamond-silicon carbide composite. It is shown that a preliminary protection of diamond crystals with the help of a-SiC nano-coating makes it possible to obtain super-hard material. Its fracture viscosity can be compared with the fracture viscosity of a hard alloy and the composite out-performs a hard alloy in respect of wear characteristics that ensures rather good prospects for its application for manufacturing logways

  14. Lead - nutritional considerations

    Science.gov (United States)

    Lead poisoning - nutritional considerations; Toxic metal - nutritional considerations ... Markowitz M. Lead poisoning. In: Kliegman RM, Behrman RE, Jenson HB, ... Emergency Medicine: Concepts and Clinical Practice . 8th ed. ...

  15. [Scaphoid fracture in motocross riders].

    Science.gov (United States)

    Knobloch, K; Krämer, R; Redeker, J; Spies, M; Vogt, P M

    2009-12-01

    Motocross racing is a demanding motorcycling discipline with significant physiological and psychological demands. Upper extremity injuries are frequently encountered. Interestingly, motocross riders present with a significantly stronger left arm, even if the left hand is not dominant. This difference is attributed to the use of the clutch lever with the left hand, which is more frequent in motocross than in Enduro or desert rally. The wrist has been reported to be involved especially among motocross racers in contrast to road racing. Besides wrist fractures, scaphoid fractures have been previously without a detailed analysis of the injury mechanism. We report on three patients suffering scaphoid fractures caused by extreme hyperextension of the wrist during landing after a motocross jump. Two patients presented late three months following the initial trauma (both Herbert type C fractures), while one motocross athlete with a B 2-type scaphoid fracture was admitted to wrist surgery within a week. The B 2-type fracture was treated with open reduction and Herbert-screw fixation, while the C-type fractures were treated by Herbert-screw fixation in addition to a cortico-cancellous bone graft. Within ten weeks after the surgery the patients were back in sport at their given preoperative level. Hyperextension rather than wrist flexion appears as the predominant mechanism of wrist injuries in motocross riders. A more axial impact on the wrist is more likely to produce a radial fracture during the landing phase. Preventive strategies are internal muscular wrist stabilisation using eccentric training and external stabilisation by rigid gloves allowing only limited hyperextension.

  16. Fracturing fluid characterization facility (FFCF)

    Energy Technology Data Exchange (ETDEWEB)

    Evans, R.D.; Roegiers, J.C.; Fagan, J.

    1993-12-31

    The Fracturing Fluid Characterization Facility project has as its main focus the design, fabrication, and construction of a high pressure simulator (HPS) and a low pressure simulator (LPS) to be used to experimentally investigate the rheological properties and transport characteristics of proppant laden fracturing fluids. A discussion of each apparatus is provided as well as the auxiliary equipment, and data acquisition and control systems associated with the simulators.

  17. Intergranular fracture in nanocrystalline metals

    Science.gov (United States)

    Farkas, D.; van Swygenhoven, H.; Derlet, P. M.

    2002-08-01

    Crack propagation studies in nanocrystalline Ni samples with mean grain sizes ranging from 5 to 12 nm are reported using atomistic simulations. For all grain sizes pure intergranular fracture is observed. Intergranular fracture is shown to proceed by the coalescence of microvoids formed at the grain boundaries ahead of the crack. The energy released during propagation is higher than the Griffith value, indicating an additional grain-boundary accommodation mechanism.

  18. Infection in periprosthetic hip fractures.

    Science.gov (United States)

    Cabral, Rui

    2012-01-01

    Fracture around the acetabulum and femur in total hip arthroplasty is a possible complication, sometimes with difficult surgical solution, namely when a sepsis is present. Periprosthetic hip fractures were classified according to a modified Vancouver classification. We treated 112 patients (67 men and 45 women) with periprosthetic hip fractures: 105 femoral fractures (94%) and seven acetabular fractures (6%). Mean follow-up was 10.6 years. For Type A (seven cases - 7%), B1 (10 cases - 10%) or C (13 cases - 12%) fractures around well fixed femoral stems we only fixed the fractures. For Type B2 (17 cases - 16%), B3 (46 cases - 44%) and D (12 cases - 11%, with associated fractures, not contemplated in the Vancouver classification) we used an uncemented long femoral stem, fixation with metallic cables and cancellous bone allografts to fill the femoral bone loss. We observed a deep infection in three patients (2.7%), three early hip dislocations treated by closed reductions, two cases with asymptomatic trochanteric non-union and one femoral refracture. In the three infection cases we performed two-stage revision with cementless hip prosthesis, using an antibiotic-loaded cement hip spacer (three to eight months), a six weeks period of parenteral antibiotics and we performed articular aspiration before revision surgery. Until now, we did not observe any re-infection. It is very important to make an early diagnosis, isolate micro-organisms and ensure their antibiotic susceptibility. The surgery solution depends on the well fixed implants and periprosthetic osteolysis and articular instability.

  19. Bilateral fracture of the superior articular process of S1 - An unusual fracture seen in a speed skater.

    Science.gov (United States)

    Kojima, Kota; Asamoto, Shunji

    2017-04-01

    Background Fractures of the superior articular process are rarely seen in clinical practice. Repetitive spinal movements may lead to fractures of the pars interarticularis, resulting in spondylolysis. Traumatic spinal fractures often involve the vertebral body, transvers and/or the spinous processes. The superior articular processes, however, are seldom involved in both traumatic and stress-induced fractures. Purpose The purpose of this report is to present an unusual case of symptomatic bilateral fracture of the superior articular process of the sacrum in a 21-year-old speed skater. Study design This is a case report. Methods The patient was admitted for close observation after complaining of excruciating lower back pain and bilateral dysesthesia along the L5 nerve root. Post-myelography computed tomography (CT) revealed a bilateral facet joint deformity at L5/S1 and a bilateral fracture of the superior articular process of the sacrum. A facet joint block at the L5/S1 joint alleviated the pain, and a nerve root block at the L5 nerve root improved the dysesthesia. The patient underwent an L5/S1 decompression, whereby the nonunion bone fragments were removed, followed by a posterior lumbar inter-body fusion (PLIF) at L5/S1. Results The patient showed immediate improvement and returned to training six months post-operatively. Conclusion We have presented a case of bilateral fractures of the superior articular process of the sacrum in a speed skater. His presenting symptoms were similar to those found in patients with spondylolysis and the etiology appears to be similar. Surgical treatment was opted given his symptomatic relief from nerve root and facet joint blocks.

  20. Definition, classification and treatment of destructive fractures

    Institute of Scientific and Technical Information of China (English)

    FANG Guo-jun; QU Zhi-guo; LIU Zhuo; CHEN Yuan

    2011-01-01

    Destructive injury is defined as a very serious damage both to the bone and the soft tissues. But in clinical practice we found that in some fracture cases, the damage to soft tissues is not as severe as "destructive injury" indicates, whereas comminuted fractures still cannot show the severity of bone damage. Therefore we proposed a new term "destructive fractures" after combining the definition of destructive injury with typical clinic cases. Destructive fractures refer to the fractures whose osseous tissues are damaged too seriously to be repaired, but soft tissues, nerves and veins are less severely injured and can be repaired. From the year 2001 to 2010, 75 cases of destructive fractures were admitted in our department. According to whether the fractures interlinked with the external environment, together with the fracture sites, they were divided into 6 types: al type, closed diaphysis destructive fracture; a2 type, open diaphysis destructive fracture; b1 type, closed joint-involved destructive fracture; b2 type,open joint-involved destructive fracture; cl type, closed mixed destructive fracture; c2 type, open mixed destructive fracture. Corresponding clinical treatments were conducted for each type.The new classification criterion of destructivefracture is simple and practical and thus can be used as an important guide to make reasonable treatment plans for destructive fractures.

  1. Maisonneuve-hyperplantarflexion variant ankle fracture.

    Science.gov (United States)

    Hinds, Richard M; Tran, Wesley H; Lorich, Dean G

    2014-11-01

    Maisonneuve fractures are rare ankle injuries, accounting for up to 7% of all ankle fractures. They consist of a proximal third fibula fracture, syndesmotic disruption, and medial ankle injury (either a deltoid ligament disruption or a medial malleolus fracture), and are often successfully managed with nonoperative treatment of the proximal fibula fracture and open reduction and internal fixation (ORIF) of the medial ankle injury and syndesmotic disruption. The hyperplantarflexion variant ankle fracture comprises approximately 7% of all ankle fractures and features dual posterior tibial lip fractures featuring a posterolateral fragment and a posteromedial fragment. Good functional results have been reported in the literature after ORIF of both the posterolateral and posteromedial fragments of this variant fracture that is not described by the Lauge-Hansen classification. In this report, the authors present the unique case of an isolated ankle fracture demonstrating characteristics of both a Maisonneuve fracture and a hyperplantarflexion variant ankle fracture. They also highlight the diagnostic imaging characteristics, including magnetic resonance imaging (MRI) and preoperative radiograph findings, surgical treatment, and postoperative clinical outcome for this patient with a Maisonneuve-hyperplantarflexion variant ankle fracture. To the authors' knowledge, this unique fracture pattern has not been reported previously in the literature. The authors conclude that although good results were seen postoperatively in this case, the importance of ORIF of both the posteromedial and posterolateral fragments of variant fractures cannot be overstated. They also found MRI to be a particularly helpful adjunct in formulating the correct diagnosis and treatment plan.

  2. Bilateral Monteggia fracture in adults

    Directory of Open Access Journals (Sweden)

    Ristić Dejan

    2011-01-01

    Full Text Available Introduction. In 1814 Giovanni Monteggia first described two cases of fractures of the proximal third of ulna with dislocation of the radial head. These fractures are more common in children than in adults, and mutual Monteggia fracture is a rare complication. This study presents a treatment course of a patient with bilateral Monteggia fracture. Case report. A 55- year-old patient was injured by falling in the yard. Radiography showed bilateral Monteggia fracture type II (by the Badon classification. Operative treatment of fracture was done by a compression plate on the right side and by the zuggurtung technique on the left one. Closed repositioning of the radial head was done on both sides. The patient was wearing a plaster splint for the upper arm for 21 days. After removing the fixation, the function of the elbow was determined by the Broberg Morrey score (BM which was on the right side 45.5 and on the left side 47.5. After the proper physical therapy, four months after the surgery, BM score was 100 on the right side, and 93 on the left one. Conclusion. Surgical treatment and early rehabilitation is the key for the return of good function of both elbows.

  3. Epidemiology of tibial shaft fractures

    Directory of Open Access Journals (Sweden)

    Grecco Marco Aurélio Sertório

    2002-01-01

    Full Text Available In this work an epidemiological analysis on tibial shaft fractures was performed. During four years, our service treated 179 fractures, 132 in male, 47 in female, aged 14 to 83 years. The 21 to 30-year-old patiens were the more injured. Of these, 120 were open and 59 close fractures of which prevailing cause was road traffic accident. The study based on patients promptuaries analyses and radiographs. The fractures occurred 97 times in the middle third (54.18%; 102 times (56.98% presented simple fragments, and 57 (31.38% oblique lines. We treated close and open fractures, respectively, 48 and 38 cases with plaster cast immobilization; 3 and 67 with external fixation after plaster cast immobilization; 5 and 12 with osteosynthesis by means of plate and screws, and 2 and 3 with external fixation only. In both close and open fractures, respectively, 7 and 20 cases of pseudarthrosis and 1 and 11 of infections have occurred. With the data obtained we verified an actual validity of the epidemiological studies as a contribution for better identifying lesions features and their treatment and complications. This allows proceedings and apprenticeship refinement.

  4. Fracture behaviour of polycrystalline tungsten

    Science.gov (United States)

    Gaganidze, Ermile; Rupp, Daniel; Aktaa, Jarir

    2014-03-01

    Fracture behaviour of round blank polycrystalline tungsten was studied by means of three point bending Fracture-Mechanical (FM) tests at temperatures between RT and 1000 °C and under high vacuum. To study the influence of the anisotropic microstructure on the fracture toughness (FT) and ductile-to-brittle transition (DBT) the specimens were extracted in three different, i.e. longitudinal, radial and circumferential orientations. The FM tests yielded distinctive fracture behaviour for each specimen orientation. The crack propagation was predominantly intergranular for longitudinal orientation up to 600 °C, whereas transgranular cleavage was observed at low test temperatures for radial and circumferentially oriented specimens. At intermediate test temperatures the change of the fracture mode took place for radial and circumferential orientations. Above 800 °C all three specimen types showed large ductile deformation without noticeable crack advancement. For longitudinal specimens the influence of the loading rate on the FT and DBT was studied in the loading rate range between 0.06 and 18 MPa m1/2/s. Though an increase of the FT was observed for the lowest loading rate, no resolvable dependence of the DBT on the loading rate was found partly due to loss of FT validity. A Master Curve approach is proposed to describe FT vs. test temperature data on polycrystalline tungsten. Fracture safe design space was identified by analysis compiled FT data.

  5. Pediatric supracondylar humerus fractures: effect of bone-implant interface conditions on fracture stability.

    Science.gov (United States)

    Lamdan, Ron; Liebergall, Meir; Gefen, Amit; Symanovsky, Naum; Peleg, Eran

    2013-12-01

    Closed reduction and percutaneous fixation with Kirschner wires (KWs) is the standard of care of pediatric supra-condylar humerus fractures (SCHFs). Failure modes leading to loss of reduction are not clear and have not been quantified. Multiple factors may weaken the KW-bone interface bonding conditions. To the best of our knowledge, the possible effect of this decrease on different KW configurations and fracture stability has never been studied. To investigate the effect of bone-KW friction conditions on SCHF post-operative mechanical stability and to formulate clinical guidelines for KW configuration under different conditions. Finite element-based model of a fixated SCHF was used to simulate structure stability for two lateral divergent versus crossed lateral and medial KW configurations under varying KW-bone friction conditions. Finite element simulations demonstrated that crossed KWs provide superior stability compared with the divergent configuration when KW-bone bonding is compromised. When KW-bone bonding conditions are adequate, crossed and divergent KW configurations provide similar, sufficient fracture stability. Under normal bone-implant interface conditions, the two diverging lateral KW configuration offers satisfactory mechanical stability and may be the preferred choice of SCHF fixation. When KW-bone bonding is suboptimal, as when one or more of the lateral KWs are re-drilled, addition of a medial KW should be considered in order to improve stability despite risk to ulnar nerve.

  6. Sacral Fracture Nonunion Treated by Bone Grafting through a Posterior Approach

    Directory of Open Access Journals (Sweden)

    Sang Yang Lee

    2013-01-01

    Full Text Available Nonunion of a sacral fracture is a rare but serious clinical condition which can cause severe chronic pain, discomfort while sitting, and significant restriction of the level of activities. Fracture nonunions reportedly occur most often after nonoperative initial treatment or inappropriate operative treatment. We report a case of fracture nonunion of the sacrum and pubic rami that resulted from non-operative initial treatment, which was treated successfully using bone grafting through a posterior approach and CT-guided percutaneous iliosacral screw fixation combined with anterior external fixation. Although autologous bone grafting has been the gold standard for the treatment of pelvic fracture nonunions, little has been written describing the approach. We utilized a posterior approach for bone grafting, which could allow direct visualization of the nonunion site and preclude nerve root injury. By this procedure, we were able to obtain the healing of fracture nonunion, leading to pain relief and functional recovery.

  7. Microstructure evolution and fracture behaviour for electron beam welding of Ti–6Al–4V

    Indian Academy of Sciences (India)

    Wu Huiqiang; Feng Jicai; He Jingshan

    2004-08-01

    The effect of microstructural characteristics on fracture behaviour mechanism for electron beam welding of Ti–6Al–4V was investigated. The results indicated that the welded microstructure composed of coarse needle + phases presenting disordered and multidirectional short needle morphology to make fracture mechanism complex. The coarse grains in weld seam with microhardness 536 HV were easy to be fractured in the region where welding heat input was ≥ 68.8 kJ/m. There exists flat curves of Ti, Al and V, Fe concentration distribution fluctuation to cause microstructural amplitude-modulated decomposition to increase the joint ductility and cleavage strength. The uneven distribution of the partial micropores located at the interior of the specimen acting as crack initiation sites lead to non-linear branch propagating path. The + interlaced structure results in the fracture location near / interface. The existence of stacking fault structure caused pile-up of dislocation to produce micropores to be new fracture initiation sites.

  8. Evaluation of Fracture Parameters for Cracks in Coupled Thermoelasticity for Functionally Graded Materials

    Directory of Open Access Journals (Sweden)

    Repka M.

    2015-11-01

    Full Text Available The finite element method (FEM is developed for coupled thermoelastic crack problems if material properties are continuously varying. The weak form is utilized to derive the FEM equations. In conventional fracture theories the state of stress and strain at the crack tip vicinity is characterized by a single fracture parameter, namely the stress intensity factor or its equivalent, J-integral. In the present paper it is considered also the second fracture parameter called as the T-stress. For evaluation of both fracture parameters the quarter-point crack tip element is developed. Simple formulas for both fracture parameters are derived comparing the variation of displacements in the quarter-point element with asymptotic expression of displacement at the crack tip vicinity. The leading terms of the asymptotic expansions of fields in the crack-tip vicinity in a functionally graded material (FGM are the same as in a homogeneous one with material coefficients taken at the crack tip.

  9. Simultaneous bilateral femoral neck fractures after electrical shock injury: a case report

    Institute of Scientific and Technical Information of China (English)

    Harminder Singh Sohal; Darsh Goyal

    2013-01-01

    Simultaneous bilateral fractures of the femoral necks are rare injuries,especially when there is no underlying pathological condition.We report a 20-year-old man who sustained bilateral femoral neck fractures resulting from an accidental electric shock with 440 Ⅴ direct current.Simultaneous bilateral femoral neck fractures after electrical shock injury without falling from a height are rather uncommon in clinic.The main cause of the fracture may be muscle contraction.This case highlights that even in the absence of primary and secondary bone disease,bilateral fractures of the femoral necks can occur following electric shock injury.We successfully managed this case with bilateral cannulated screw fixation without bone grafting.Surgeons caring for patients with electrical injury should be aware of the possibility of skeletal injuries which can go unnoticed,leading to delay in diagnosis and increased risk of complications.

  10. Linking advanced fracture models to structural analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chiesa, Matteo

    2001-07-01

    Shell structures with defects occur in many situations. The defects are usually introduced during the welding process necessary for joining different parts of the structure. Higher utilization of structural materials leads to a need for accurate numerical tools for reliable prediction of structural response. The direct discretization of the cracked shell structure with solid finite elements in order to perform an integrity assessment of the structure in question leads to large size problems, and makes such analysis infeasible in structural application. In this study a link between local material models and structural analysis is outlined. An ''ad hoc'' element formulation is used in order to connect complex material models to the finite element framework used for structural analysis. An improved elasto-plastic line spring finite element formulation, used in order to take cracks into account, is linked to shell elements which are further linked to beam elements. In this way one obtain a global model of the shell structure that also accounts for local flexibilities and fractures due to defects. An important advantage with such an approach is a direct fracture mechanics assessment e.g. via computed J-integral or CTOD. A recent development in this approach is the notion of two-parameter fracture assessment. This means that the crack tip stress tri-axiality (constraint) is employed in determining the corresponding fracture toughness, giving a much more realistic capacity of cracked structures. The present thesis is organized in six research articles and an introductory chapter that reviews important background literature related to this work. Paper I and II address the performance of shell and line spring finite elements as a cost effective tool for performing the numerical calculation needed to perform a fracture assessment. In Paper II a failure assessment, based on the testing of a constraint-corrected fracture mechanics specimen under tension, is

  11. Cryogenic current leads

    Energy Technology Data Exchange (ETDEWEB)

    Zizek, F.

    1982-01-01

    Theoretical, technical and design questions are examined of cryogenic current leads for SP of magnetic systems. Simplified mathematical models are presented for the current leads. To illustrate modeling, the calculation is made of the real current leads for 500 A and three variants of current leads for 1500 A for the enterprise ''Shkoda.''

  12. Learn about Lead

    Science.gov (United States)

    ... old and younger are most susceptible to the effects of lead. Children Even low levels of lead in the blood ... simple blood test to check you or your child for lead exposure. You may also want to test your home for sources ... and Technology Lead Laws and Regulations Outreach and Grants En ...

  13. Rockfall triggering by cyclic thermal stressing of exfoliation fractures

    Science.gov (United States)

    Collins, Brian; Stock, Greg M.

    2016-01-01

    Exfoliation of rock deteriorates cliffs through the formation and subsequent opening of fractures, which in turn can lead to potentially hazardous rockfalls. Although a number of mechanisms are known to trigger rockfalls, many rockfalls occur during periods when likely triggers such as precipitation, seismic activity and freezing conditions are absent. It has been suggested that these enigmatic rockfalls may occur due to solar heating of rock surfaces, which can cause outward expansion. Here we use data from 3.5 years of field monitoring of an exfoliating granite cliff in Yosemite National Park in California, USA, to assess the magnitude and temporal pattern of thermally induced rock deformation. From a thermodynamic analysis, we find that daily, seasonal and annual temperature variations are sufficient to drive cyclic and cumulative opening of fractures. Application of fracture theory suggests that these changes can lead to further fracture propagation and the consequent detachment of rock. Our data indicate that the warmest times of the day and year are particularly conducive to triggering rockfalls, and that cyclic thermal forcing may enhance the efficacy of other, more typical rockfall triggers.

  14. Rockfall triggering by cyclic thermal stressing of exfoliation fractures

    Science.gov (United States)

    Collins, Brian D.; Stock, Greg M.

    2016-05-01

    Exfoliation of rock deteriorates cliffs through the formation and subsequent opening of fractures, which in turn can lead to potentially hazardous rockfalls. Although a number of mechanisms are known to trigger rockfalls, many rockfalls occur during periods when likely triggers such as precipitation, seismic activity and freezing conditions are absent. It has been suggested that these enigmatic rockfalls may occur due to solar heating of rock surfaces, which can cause outward expansion. Here we use data from 3.5 years of field monitoring of an exfoliating granite cliff in Yosemite National Park in California, USA, to assess the magnitude and temporal pattern of thermally induced rock deformation. From a thermodynamic analysis, we find that daily, seasonal and annual temperature variations are sufficient to drive cyclic and cumulative opening of fractures. Application of fracture theory suggests that these changes can lead to further fracture propagation and the consequent detachment of rock. Our data indicate that the warmest times of the day and year are particularly conducive to triggering rockfalls, and that cyclic thermal forcing may enhance the efficacy of other, more typical rockfall triggers.

  15. Optimal scaling in ductile fracture

    Science.gov (United States)

    Fokoua Djodom, Landry

    This work is concerned with the derivation of optimal scaling laws, in the sense of matching lower and upper bounds on the energy, for a solid undergoing ductile fracture. The specific problem considered concerns a material sample in the form of an infinite slab of finite thickness subjected to prescribed opening displacements on its two surfaces. The solid is assumed to obey deformation-theory of plasticity and, in order to further simplify the analysis, we assume isotropic rigid-plastic deformations with zero plastic spin. When hardening exponents are given values consistent with observation, the energy is found to exhibit sublinear growth. We regularize the energy through the addition of nonlocal energy terms of the strain-gradient plasticity type. This nonlocal regularization has the effect of introducing an intrinsic length scale into the energy. We also put forth a physical argument that identifies the intrinsic length and suggests a linear growth of the nonlocal energy. Under these assumptions, ductile fracture emerges as the net result of two competing effects: whereas the sublinear growth of the local energy promotes localization of deformation to failure planes, the nonlocal regularization stabilizes this process, thus resulting in an orderly progression towards failure and a well-defined specific fracture energy. The optimal scaling laws derived here show that ductile fracture results from localization of deformations to void sheets, and that it requires a well-defined energy per unit fracture area. In particular, fractal modes of fracture are ruled out under the assumptions of the analysis. The optimal scaling laws additionally show that ductile fracture is cohesive in nature, i.e., it obeys a well-defined relation between tractions and opening displacements. Finally, the scaling laws supply a link between micromechanical properties and macroscopic fracture properties. In particular, they reveal the relative roles that surface energy and microplasticity

  16. Bazı arpa genotiplerinin Drechslera teres f. maculata(Smed.-Pet., 1971)'ya karşı fide dönemi reaksiyonlarının belirlenmesi

    OpenAIRE

    AKTAŞDOĞAN, Duygu; KARAKAYA, Aziz; ÇELİK OĞUZ, Arzu; MERT, Zafer; SAYİM, İsmail; ERGÜN, Namuk; AYDOĞAN, Sinan

    2013-01-01

    Üç arpa çeşidinin, 2 arpa çeşit adayının ve 20 ileri kademe arpa hattının Drechslera teres f. maculata (Smed.-Pet., 1971)'nın Sivas ve Eskişehir illerinden elde edilmiş iki izolatına karşı sera koşullarında fide dönemi reaksiyonları belirlenmiştir. Bülbül 89 çeşidi Sivas izolatına orta derecede hassas-hassas reaksiyon gösterirken Eskişehir izolatına orta derecede hassas reaksiyon göstermiştir. Avcı 2002 çeşidi her iki izolata da dayanıklı-orta derecede dayanıklı reaksiyon göstermiştir. Aydanh...

  17. [Bone fracture and the healing mechanisms. Fragility fracture and bone quality].

    Science.gov (United States)

    Mawatari, Taro; Iwamoto, Yukihide

    2009-05-01

    Fracture occurs in bone having less than normal elastic resistance without any violence. Numerous terms have been used to classify various types of fractures from low trauma events; "fragility fracture", "stress fracture", "insufficiency fracture", "fatigue fracture", "pathologic fracture", etc. The definitions of these terms and clinical characteristics of these fractures are discussed. Also state-of-the-art bone quality assessments; Finite element analysis of clinical CT scans, assessments of the Microdamage, and the Cross-links of Collagen are introduced in this review.

  18. A 3-Dimensional discrete fracture network generator to examine fracture-matrix interaction using TOUGH2

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Kazumasa; Yongkoo, Seol

    2003-04-09

    Water fluxes in unsaturated, fractured rock involve the physical processes occurring at fracture-matrix interfaces within fracture networks. Modeling these water fluxes using a discrete fracture network model is a complicated effort. Existing preprocessors for TOUGH2 are not suitable to generate grids for fracture networks with various orientations and inclinations. There are several 3-D discrete-fracture-network simulators for flow and transport, but most of them do not capture fracture-matrix interaction. We have developed a new 3-D discrete-fracture-network mesh generator, FRACMESH, to provide TOUGH2 with information about the fracture network configuration and fracture-matrix interactions. FRACMESH transforms a discrete fracture network into a 3 dimensional uniform mesh, in which fractures are considered as elements with unique rock material properties and connected to surrounding matrix elements. Using FRACMESH, individual fractures may have uniform or random aperture distributions to consider heterogeneity. Fracture element volumes and interfacial areas are calculated from fracture geometry within individual elements. By using FRACMESH and TOUGH2, fractures with various inclinations and orientations, and fracture-matrix interaction, can be incorporated. In this paper, results of flow and transport simulations in a fractured rock block utilizing FRACMESH are presented.

  19. Fracture Union in Closed Interlocking Nail in Humeral Shaft Fractures

    Institute of Scientific and Technical Information of China (English)

    Ramji Lal Sahu; Rajni Ranjan; Ajay Lal

    2015-01-01

    Background:Fracture shaft humerus is a major cause of morbidity in patients with upper extremity injuries.The aim of this study was to evaluate the outcome of interlocking nail in humeral shaft fractures.Methods:This study was conducted in the Department of Orthopedic Surgery in SMS and R Sharda University from January 2010 to November 2013.Seventy-eight patients were recruited from emergency and out-patient department having a close fracture of humerus shaft.All patients were operated under general anesthesia and closed reamed interlocking nailing was done.All patients were followed for 9 months.Results:Out of 78 patients,69 patients underwent union in 90-150 days with a mean of 110.68 days.Complications found in four patients who had nonunion,and five patients had delayed union,which was treated with bone grafting.All the patients were assessed clinically and radiologically for fracture healing,joint movements and implant failure.The results were excellent in 88.46% and good in 6.41% patients.Complete subjective,functional,and clinical recovery had occurred in almost 100% of the patients.Conclusions:The results of the present study indicates that in the presence of proper indications,reamed antegrade intramedullary interlocked nailing appears to be a method of choice for internal fixation of osteoporotic and pathologic fractures.

  20. COMBINED DAMAGE FRACTURE CRITERIA FOR PIEZOELECTRIC CERAMICS

    Institute of Scientific and Technical Information of China (English)

    Yang Xinhua; Chen Chuanyao; Hu Yuantai; Wang Cheng

    2005-01-01

    Mechanical and electrical damages are introduced to study the fracture mechanics of piezoelectric ceramics in this paper. Two kinds of piezoelectric fracture criteria are established using the method of least squares combined with a damage analysis of the well-known piezoelectric fracture experiments of Park and Sun's. One is based on a linear combination of the mechanical and electrical damages and the other on their nonlinear combination. When the combined damage D is up to its critical value Dc, piezoelectric fracture occurs. It is found from the qualitative comparison of the numerical results with the experimental data that the nonlinearly combined damage fracture criterion can give a better prediction of piezoelectric fracture. And it is concluded from the nonlinearly combined damage fracture criterion that a negative electric field impedes fracture whereas the effect of a positive electric field on fracture depends on its magnitude.