Length-scale dependent ensemble-averaged conductance of a 1D disordered conductor: Conductance minimum

International Nuclear Information System (INIS)

Tit, N.; Kumar, N.; Pradhan, P.

1993-07-01

Exact numerical calculation of ensemble averaged length-scale dependent conductance for the 1D Anderson model is shown to support an earlier conjecture for a conductance minimum. Numerical results can be understood in terms of the Thouless expression for the conductance and the Wigner level-spacing statistics. (author). 8 refs, 2 figs

Instantaneous equations for multiphase flow in porous media without length-scale restrictions using a non-local averaging volume

International Nuclear Information System (INIS)

Espinosa-Paredes, Gilberto

2010-01-01

The aim of this paper is to propose a framework to obtain a new formulation for multiphase flow conservation equations without length-scale restrictions, based on the non-local form of the averaged volume conservation equations. The simplification of the local averaging volume of the conservation equations to obtain practical equations is subject to the following length-scale restrictions: d << l << L, where d is the characteristic length of the dispersed phases, l is the characteristic length of the averaging volume, and L is the characteristic length of the physical system. If the foregoing inequality does not hold, or if the scale of the problem of interest is of the order of l, the averaging technique and therefore, the macroscopic theories of multiphase flow should be modified in order to include appropriate considerations and terms in the corresponding equations. In these cases the local form of the averaged volume conservation equations are not appropriate to describe the multiphase system. As an example of the conservation equations without length-scale restrictions, the natural circulation boiling water reactor was consider to study the non-local effects on the thermal-hydraulic core performance during steady-state and transient behaviors, and the results were compared with the classic local averaging volume conservation equations.

Estimation of the crack propagation direction in a mixed-mode geometry via multi-parameter fracture criteria

Czech Academy of Sciences Publication Activity Database

Malíková, L.; Veselý, V.; Seitl, Stanislav

2015-01-01

Roč. 9, č. 33 (2015), s. 25-32 ISSN 1971-8993 Institutional support: RVO:68081723 Keywords : Near-crack-tip fields * Williams expansion * Crack propagation direction * Multi-parameter fracture criteria * Finite element analysis Subject RIV: JL - Materials Fatigue, Friction Mechanics

The length-scale dependence of strain in networks by SANS

CERN Document Server

Pyckhout-Hintzen, W; Heinrich, M; Richter, D; Westermann, S; Straube, E

2002-01-01

We present a SANS study of the length-scale dependence of chain deformation by means of a suitable labeling in dense, cross-linked elastomers of the HDH-type. This length scale is controlled by the size of the label as well as the cross-link density. The results are compared to long homopolymers. The data are analyzed by means of the tube model of topology in rubber elasticity in combination with the random-phase approximation (RPA) to account for interchain correlations. Chain degradation during cross linking is treated by the standard RPA approach for polydisperse multicomponent systems. A transition from locally freely fluctuating to tube-constrained segmental motion was observed. (orig.)

A Study On Critical Thinning In Thin-walled Tube Bending Of Al-Alloy 5052O Via Coupled Ductile Fracture Criteria

International Nuclear Information System (INIS)

Li Heng; Yang He; Zhan Mei

2010-01-01

Thin-walled tube bending(TWTB) method of Al-alloy tube has attracted wide applications in aerospace, aviation and automobile,etc. While, under in-plane double tensile stress states at the extrados of bending tube, the over-thinning induced ductile fracture is one dominant defect in Al-alloy tube bending. The main objective of this study is to predict the critical wall-thinning of Al-alloy tube bending by coupling two ductile fracture criteria(DFCs) into FE simulation. The DFCs include Continuum Damage Mechanics(CDM)-based model and GTN porous model. Through the uniaxial tensile test of the curved specimen, the basic material properties of the Al-alloy 5052O tube is obtained; via the inverse problem solution, the damage parameters of both the two fracture criteria are interatively determined. Thus the application study of the above DFCs in the TWTB is performed, and the more reasonable one is selected to obtain the critical thinning of Al-alloy tube in bending. The virtual damage initiation and evolution (when and where the ductile fracture occurs) in TWTB are investigated, and the fracture mechanisms of the voided Al-alloy tube in tube bending are consequently discussed.

Crack propagation direction in a mixed mode geometry estimated via multi-parameter fracture criteria

Czech Academy of Sciences Publication Activity Database

Malíková, L.; Veselý, V.; Seitl, Stanislav

2016-01-01

Roč. 89, AUG (2016), s. 99-107 ISSN 0142-1123. [International Conference on Characterisation of Crack Tip Fields /3./. Urbino, 20.04.2015-22.04.2015] Institutional support: RVO:68081723 Keywords : Near-crack-tip fields * Mixed mode * Crack propagation direction * Multi-parameter fracture criteria * Finite element analysis Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.899, year: 2016

Temporal and Latitudinal Variations of the Length-Scales and Relative Intensities of the Chromospheric Network

Science.gov (United States)

Raju, K. P.

2018-05-01

The Calcium K spectroheliograms of the Sun from Kodaikanal have a data span of about 100 years and covers over 9 solar cycles. The Ca line is a strong chromospheric line dominated by chromospheric network and plages which are good indicators of solar activity. Length-scales and relative intensities of the chromospheric network have been obtained in the solar latitudes from 50 degree N to 50 degree S from the spectroheliograms. The length-scale was obtained from the half-width of the two-dimensional autocorrelation of the latitude strip which gives a measure of the width of the network boundary. As reported earlier for the transition region extreme ultraviolet (EUV) network, relative intensity and width of the chromospheric network boundary are found to be dependent on the solar cycle. A varying phase difference has been noticed in the quantities in different solar latitudes. A cross-correlation analysis of the quantities from other latitudes with ±30 degree latitude revealed an interesting phase difference pattern indicating flux transfer. Evidence of equatorward flux transfer has been observed. The average equatorward flux transfer was estimated to be 5.8 ms-1. The possible reasons of the drift could be meridional circulation, torsional oscillations, or the bright point migration. Cross-correlation of intensity and length-scale from the same latitude showed increasing phase difference with increasing latitude. We have also obtained the cross correlation of the quantities across the equator to see the possible phase lags in the two hemispheres. Signatures of lags are seen in the length scales of southern hemisphere near the equatorial latitudes, but no such lags in the intensity are observed. The results have important implications on the flux transfer over the solar surface and hence on the solar activity and dynamo.

On the failure analysis of bondlines: Stress or energy based fracture criteria?

DEFF Research Database (Denmark)

Anyfantis, Konstantinos

2014-01-01

that characterizes a given bondline, both its cohesive strength and fracture toughness material parameters must be experimentally defined. Based on these properties, failure analysis of the bondline can be done either through stress- or energy-based criteria. The aim of this work is to investigate the effectiveness...... to classify the wide range of bondlines with respect to the failure theory that best describes the debonding process. Cohesive length scale effects are first demonstrated by modeling end notch flexure geometries and later by modeling double strap joint geometries within the framework of a wide numerical...

Hot and Steamy Fractures in the Philippines: The Geological Characterization and Permeability Evaluation of Fractures in the Southern Negros Geothermal Field, Philippines

Science.gov (United States)

Pastoriza, L. R.; Holdsworth, R.; McCaffrey, K. J. W.; Dempsey, E. D.; Walker, R. J.; Gluyas, J.; Reyes, J. K.

2016-12-01

Fluid flow pathway characterization is critical to geothermal exploration and exploitation. It requires a good understanding of the structural evolution, fault distribution and fluid flow properties. A dominantly fieldwork-based approach has been used to evaluate the potential fracture permeability characteristics of a typical high-temperature geothermal reservoir in the Southern Negros Geothermal Field, Philippines. This is a liquid-dominated geothermal resource hosted in the andesitic to dacitic Quaternary Cuernos de Negros Volcano in Negros Island. Fieldwork reveals two main fracture groups based on fault rock characteristics, alteration type, relative age of deformation, and associated thermal manifestation, with the younger fractures mainly related to the development of the modern geothermal system. Palaeostress analyses of cross-cutting fault and fracture arrays reveal a progressive counterclockwise rotation of stress axes from the (?)Pliocene up to the present-day, which is consistent with the regional tectonic models. A combined slip and dilation tendency analysis of the mapped faults indicates that NW-SE structures should be particularly promising drilling targets. Frequency versus length and aperture plots of fractures across six to eight orders of magnitude show power-law relationships with a change in scaling exponent in the region of 100 to 500m length-scales. Finally, evaluation of the topology of the fracture branches shows the dominance of Y-nodes that are mostly doubly connected suggesting good connectivity and permeability within the fracture networks. The results obtained in this study illustrate the value of methods that can be globally applied during exploration to better characterize fracture systems in geothermal reservoirs using multiscale datasets.

Hot and steamy fractures in the Philippines: the characterisation and permeability evaluation of fractures of the Southern Negros Geothermal Field, Negros Oriental, Philippines

Science.gov (United States)

Pastoriza, Loraine; Holdsworth, Robert; McCaffrey, Kenneth; Dempsey, Eddie; Walker, Richard; Gluyas, Jon; Reyes, Jonathan

2017-04-01

Fluid flow pathway characterisation is critical to geothermal exploration and exploitation. It requires a good understanding of the structural evolution, fault distribution and fluid flow properties. A dominantly fieldwork-based approach has been used to evaluate the potential fracture permeability characteristics of a typical high-temperature geothermal reservoir in the Southern Negros Geothermal Field, Philippines. This is a liquid-dominated geothermal resource hosted in the andesitic to dacitic Quaternary Cuernos de Negros Volcano in Negros Island. Fieldwork reveals two main fracture groups based on fault rock characteristics, alteration type, relative age of deformation, and associated thermal manifestation, with the younger fractures mainly related to the development of the modern geothermal system. Palaeostress analyses of cross-cutting fault and fracture arrays reveal a progressive counterclockwise rotation of stress axes from the (?)Pliocene up to the present-day, which is consistent with the regional tectonic models. A combined slip and dilation tendency analysis of the mapped faults indicates that NW-SE structures should be particularly promising drilling targets. Frequency versus length and aperture plots of fractures across six to eight orders of magnitude show power-law relationships with a change in scaling exponent in the region of 100 to 500m length-scales. Finally, evaluation of the topology of the fracture branches shows the dominance of Y-nodes that are mostly doubly connected suggesting good connectivity and permeability within the fracture networks. The results obtained in this study illustrate the value of methods that can be globally applied during exploration to better characterize fracture systems in geothermal reservoirs using multiscale datasets.

Evaluation criteria of structural steel reliability

International Nuclear Information System (INIS)

Zav'yalov, A.S.

1980-01-01

Different low-carbon and medium-carbon structural steels are investigated. It is stated that steel reliability evaluation criteria depend on the fracture mode, steel suffering from the brittle fracture under the influence of the stresses (despite their great variety) arising in articles during the production and operation. Fibrous steel fracture at the given temperature and article thickness says about its high ductility and toughness and brittle fractures are impossible. Brittle fractures take place in case of a crystalline and mixed fracture with a predominant crystalline component. Evaluation methods of article and sample steel structural strength differing greatly from real articles in a thickness (diameter) or used at temperatures higher than possible operation temperatures cannot be reliability evaluation criteria because at a great thickness (diameter) and lower operation temperatures steel fracture and its strain mode can change resulting in a sharp reliability degradation

Single and multiple transverse fracture initiation from horizontal wells

Energy Technology Data Exchange (ETDEWEB)

Crosby, D.G.; Rahman, M.M.; Rahman, M.K.; Rahman, S.S. [School of Petroleum Engineering, The University of New South Wales, 2052 Sydney (Australia)

2002-08-01

The results of an analytical and experimental study of the initiation of transverse fractures from horizontal wells are presented. Analytical criteria for the initiation of single hydraulic fracture are reviewed, and criterion for initiation of multiple hydraulic fractures was developed by modification of the existing Drucker and Prager criterion for single hydraulic fracture initiation. The developed criterion for multiple fracture initiation was validated by comparisons with actual hydraulic fracture initiation pressures, which were obtained from scaled laboratory experiments and numerical results from boundary element analysis. Other criteria are assessed against the experimental results. Experimentally obtained transverse fracture initiation pressures were found close to longitudinal fracture initiation pressures estimated from maximum tensile stress criterion and Hoek and Brown criterion. One possible explanation of this finding is presented. Results from Drucker and Prager criteria for single and multiple fracture initiation were, however, found closer to experimental values. Therefore, these criteria could be useful to engineers involved with hydraulic fracturing for predicting transverse fracture initiation pressures from horizontal wells drilled parallel to the minimum horizontal in-situ stress.

Mode II brittle fracture: recent developments

Directory of Open Access Journals (Sweden)

A. Campagnolo

2017-10-01

Full Text Available Fracture behaviour of V-notched specimens is assessed using two energy based criteria namely the averaged strain energy density (SED and Finite Fracture Mechanics (FFM. Two different formulations of FFM criterion are considered for fracture analysis. A new formulation for calculation of the control radius Rc under pure Mode II loading is presented and used for prediction of fracture behaviour. The critical Notch Stress Intensity Factor (NSIF at failure under Mode II loading condition can be expressed as a function of notch opening angle. Different formulations of NSIFs are derived using the three criteria and the results are compared in the case of sharp V-notched brittle components under in-plane shear loading, in order to investigate the ability of each method for the fracture assessment. For this purpose, a bulk of experimental data taken from the literature is employed for the comparison among the mentioned criteria

The generalized fracture criteria based on the multi-parameter representation of the crack tip stress field

Science.gov (United States)

Stepanova, L. V.

2017-12-01

The paper is devoted to the multi-parameter asymptotic description of the stress field near the crack tip of a finite crack in an infinite isotropic elastic plane medium subject to 1) tensile stress; 2) in-plane shear; 3) mixed mode loading for a wide range of mode-mixity situations (Mode I and Mode II). The multi-parameter series expansion of stress tensor components containing higher-order terms is obtained. All the coefficients of the multiparameter series expansion of the stress field are given. The main focus is on the discussion of the influence of considering the higher-order terms of the Williams expansion. The analysis of the higher-order terms in the stress field is performed. It is shown that the larger the distance from the crack tip, the more terms it is necessary to keep in the asymptotic series expansion. Therefore, it can be concluded that several more higher-order terms of the Williams expansion should be used for the stress field description when the distance from the crack tip is not small enough. The crack propagation direction angle is calculated. Two fracture criteria, the maximum tangential stress criterion and the strain energy density criterion, are used. The multi-parameter form of the two commonly used fracture criteria is introduced and tested. Thirty and more terms of the Williams series expansion for the near-crack-tip stress field enable the angle to be calculated more precisely.

Fracture mechanisms and fracture control in composite structures

Science.gov (United States)

Kim, Wone-Chul

Four basic failure modes--delamination, delamination buckling of composite sandwich panels, first-ply failure in cross-ply laminates, and compression failure--are analyzed using linear elastic fracture mechanics (LEFM) and the J-integral method. Structural failures, including those at the micromechanical level, are investigated with the aid of the models developed, and the critical strains for crack propagation for each mode are obtained. In the structural fracture analyses area, the fracture control schemes for delamination in a composite rib stiffener and delamination buckling in composite sandwich panels subjected to in-plane compression are determined. The critical fracture strains were predicted with the aid of LEFM for delamination and the J-integral method for delamination buckling. The use of toughened matrix systems has been recommended for improved damage tolerant design for delamination crack propagation. An experimental study was conducted to determine the onset of delamination buckling in composite sandwich panel containing flaws. The critical fracture loads computed using the proposed theoretical model and a numerical computational scheme closely followed the experimental measurements made on sandwich panel specimens of graphite/epoxy faceskins and aluminum honeycomb core with varying faceskin thicknesses and core sizes. Micromechanical models of fracture in composites are explored to predict transverse cracking of cross-ply laminates and compression fracture of unidirectional composites. A modified shear lag model which takes into account the important role of interlaminar shear zones between the 0 degree and 90 degree piles in cross-ply laminate is proposed and criteria for transverse cracking have been developed. For compressive failure of unidirectional composites, pre-existing defects play an important role. Using anisotropic elasticity, the stress state around a defect under a remotely applied compressive load is obtained. The experimentally

Application of Finite Element Method to Analyze the Influences of Process Parameters on the Cut Surface in Fine Blanking Processes by Using Clearance-Dependent Critical Fracture Criteria

Directory of Open Access Journals (Sweden)

Phyo Wai Myint

2018-04-01

Full Text Available The correct choice of process parameters is important in predicting the cut surface and obtaining a fully-fine sheared surface in the fine blanking process. The researchers used the value of the critical fracture criterion obtained by long duration experiments to predict the conditions of cut surfaces in the fine blanking process. In this study, the clearance-dependent critical ductile fracture criteria obtained by the Cockcroft-Latham and Oyane criteria were used to reduce the time and cost of experiments to obtain the value of the critical fracture criterion. The Finite Element Method (FEM was applied to fine blanking processes to study the influences of process parameters such as the initial compression, the punch and die corner radii and the shape and size of the V-ring indenter on the length of the sheared surface. The effects of stress triaxiality and punch diameters on the cut surface produced by the fine blanking process are also discussed. The verified process parameters and tool geometry for obtaining a fully-fine sheared SPCC surface are described. The results showed that the accurate and stable prediction of ductile fracture initiation can be achieved using the Oyane criterion.

Computerized tomographic diagnosis of basal skull fracture

International Nuclear Information System (INIS)

Tanaka, Tokutaro; Shimoyama, Ichiro; Endoh, Mitsutoshi; Ninchoji, Toshiaki; Uemura, Kenichi.

1984-01-01

The diagnosis of basal skull fractures used to be difficult, particularly on the basis of routine skull roentgenography alone. We have now examined the diagnostic value of conventional computerized tomography in basal skull fractures. We studied 82 cases clinically diagnosed as basal skull fractures. We examined them based on at least one of the following computerized tomographic criteria for basal skull fractures: 1) fracture line(s), 2) intracranial air, 3) fluid in the paranasal sinuses, and 4) fluid in the middle ear, including the mastoid air cells. The signs of the fracture line and of the intracranial air are definite indications of basal skull fracture, but the signs of fluid in the paranasal sinuses and/or in the middle ear are not definite. When combined, however, with such other clinical signs as black eye, Battle's sign, CSF leakage, CSF findings, and profuse nasal or ear bleeding, the diagnosis is more reliable. Seventy cases (85.4%) in this series had basal skull fractures according to our computerized tomographic criteria. Among them , 26 cases (31.7%) were diagnosed with fracture lines, 17 cases (20.7%) with intracranial air, 16 cases (19.5%) with fluid in the paranasal sinuses, 10 cases (12.2%) with fluid in the middle ear, and one case (1.2%) with fluid in both. Twelve cases (14.6%) of the 82 cases clinically diagnosed as basal skull fractures could not have been diagnosed on our computerized tomographic criteria alone. We diagnosed them because of CSF leakage, CSF findings, surgical findings, etc. (author)

Development of a plastic fracture methodology. Final report

International Nuclear Information System (INIS)

Kanninen, M.F.; Hahn, G.T.; Broek, D.; Stonesifer, R.B.; Marschall, C.W.; Abou-Sayed, I.S.; Zahoor, A.

1981-03-01

A number of candidate fracture criteria were investigated to determine the basis for plastic fracture mechanics assessments of nuclear pressure vessels and other components exhibiting fully ductile behavior. The research was comprised of an integrated combination of stable crack growth experiments and elastic-plastic finite element analyses. The results demonstrated that many different fracture criteria can be used as the basis of a resistance curve approach to predicting stable crack growth and fracture instability. All have some disadvantages and none is completely unacceptable. On balance, the best criteria were found to be the J-integral for initiation and limited amounts of stable crack growth and the local crack tip opening angle for extended amounts of stable growth. A combination of the two, which may preserve the advantages of each while reducing their disadvantages, was also suggested by these results

Development of a plastic fracture methodology. Final report

Energy Technology Data Exchange (ETDEWEB)

Kanninen, M.F.; Hahn, G.T.; Broek, D.; Stonesifer, R.B.; Marschall, C.W.; Abou-Sayed, I.S.; Zahoor, A.

1981-03-01

A number of candidate fracture criteria were investigated to determine the basis for plastic fracture mechanics assessments of nuclear pressure vessels and other components exhibiting fully ductile behavior. The research was comprised of an integrated combination of stable crack growth experiments and elastic-plastic finite element analyses. The results demonstrated that many different fracture criteria can be used as the basis of a resistance curve approach to predicting stable crack growth and fracture instability. All have some disadvantages and none is completely unacceptable. On balance, the best criteria were found to be the J-integral for initiation and limited amounts of stable crack growth and the local crack tip opening angle for extended amounts of stable growth. A combination of the two, which may preserve the advantages of each while reducing their disadvantages, was also suggested by these results.

Cemented Hemiarthroplasty in Elderly Osteoporotic Unstable Trochanteric Fractures using Fracture Window

Directory of Open Access Journals (Sweden)

Thakur A

2016-03-01

Full Text Available Introduction: We would like to analyze the role of cemented hemiarthroplasty in elderly osteoporotic unstable intertrochanteric fractures through trochanteric fracture window. Materials and Methods: The study was conducted from July 2011 to July 2014. From a total of 265 consecutive patients with intertrochanteric fractures of 42 patients were selected according to inclusion criteria and results were analyzed prospectively. All patients were operated at tertiary care institute. Patients which matched the inclusion criteria were selected. 42 patients entered the study and all completed the study. Primary cemented hemiarthroplasty was done in all patients. Modified Harris Hip Score was used to assess all the patients. Results: 42 patients were included in the study with an average age of 80.7 years. Only AO/OTA type 31-A2.2 and 31-A2.3 were included, average HHS at final follow up of three years was 86.2. No revision or reoperation was done. Conclusion: In a selected cohort of patients primary prosthetic replacement in elderly osteoporotic unstable intertrochanteric fractures is good option and the surgical technique allowed us to perform it more easily.

A stress-based fracture criteria validated on mixed microstructures of ferrite and bainite over a range of stress triaxialities

Energy Technology Data Exchange (ETDEWEB)

Golling, Stefan, E-mail: stefan.golling@ltu.se [Luleå University of Technology, SE 971 87 Luleå (Sweden); Östlund, Rickad [Gestamp HardTech, Ektjärnsvägen 5, SE 973 45 Luleå (Sweden); Oldenburg, Mats [Luleå University of Technology, SE 971 87 Luleå (Sweden)

2016-09-30

Hot stamping is a sequential process for formation and heat-treatment of sheet metal components with superior mechanical properties. By applying different cooling rates, the microstructural composition and thus the material properties of steel can be designed. By controlling the cooling rate in different sections of a blank, the material properties can be tailored depending on the desired toughness. Under continuous cooling, various volume fractions of ferrite and bainite are formed depending on the rate of cooling. This paper focuses on the ductile fracture behavior of a thin sheet metal made of low-alloyed boron steel with varying amounts of ferrite and bainite. An experimental setup was applied in order to produce microstructures with different volume fractions of ferrite and bainite. In total, five different test specimen geometries, representing different stress triaxialities, were heat treated and tensile tested. Through full-field measurements, flow curves extending beyond necking and the equivalent plastic strain to fracture were determined. Experimental results were further investigated using a mean-field homogenization scheme combined with local fracture criteria. The mean-field homogenization scheme comprises the influence of microstructure composition and stress triaxiality with usable accuracy, connoting auspicious possibilities for constitutive modeling of hot-stamped components.

Criteria of validity in the measurement of shearing fracture toughness; Gueltigkeitskriterien zur Bestimmung von Scherbruchzaehigkeiten

Energy Technology Data Exchange (ETDEWEB)

Hiese, W

2000-01-01

The investigations aimed at the development of criteria for measuring valid shearing fracture toughness data K{sub IIc} in analogy to the measurement of mode-I fracture toughness K{sub Ie}. Details are presented, and practical recommendations are given. [German] Die Brucheigenschaften von Werkstoffen werden ueblicherweise unter Zugbeanspruchungsbedingungen (Mode-I) bestimmt. Im Anwendungsbereich der linear-elastischen Bruchmechanik bzw. des Kleinbereichsfliessens geschieht dieses in Form der Bruchzaehigkeit K{sub Ic}. Es existieren entsprechende Richtlinien zur Durchfuehrung des Tests sowie zur Registrierung und Auswertung der Daten. Diese Kriterien sind in Standards festgelegt. Empfehlungen zur Bestimmung der Bruchzaehigkeit K{sub IIc} unter ebener Scherbelastung (Mode-II) fuer Werkstoffe mit im wesentlichen linear-elastischem Verhalten existieren nicht. Im Rahmen dieser Arbeit werden durch den Vergleich der Groesse der plastischen Rissspitzenzonen im Verhaeltnis zu den Abmessungen von Probe bzw. Bauteil Kriterien zur Messung gueltiger Scherbruchzaehigkeiten K{sub IIc} analog zur Messung der Mode-I-Bruchzaehigkeit K{sub Ic} entwickelt. Der Groessenvergleich der plastischen Rissspitzenzonen fuer beide Beanspruchungsarten zeigt unter aequivalenten Beanspruchungen, d.h. K{sub II}=K{sub I}, dass bei Mode-II beanspruchten Rissen die plastischen Zonen groesser, aber die Differenzen in der Groesse der plastischen Zonen fuer die Zustaende ebener Spannung und ebener Dehnung kleiner sind als unter entsprechenden Mode-I-Beanspruchungen.

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...

Spontaneous symmetry breaking in vortex systems with two repulsive lengthscales.

Science.gov (United States)

Curran, P J; Desoky, W M; Milosević, M V; Chaves, A; Laloë, J-B; Moodera, J S; Bending, S J

2015-10-23

Scanning Hall probe microscopy (SHPM) has been used to study vortex structures in thin epitaxial films of the superconductor MgB2. Unusual vortex patterns observed in MgB2 single crystals have previously been attributed to a competition between short-range repulsive and long-range attractive vortex-vortex interactions in this two band superconductor; the type 1.5 superconductivity scenario. Our films have much higher levels of disorder than bulk single crystals and therefore both superconducting condensates are expected to be pushed deep into the type 2 regime with purely repulsive vortex interactions. We observe broken symmetry vortex patterns at low fields in all samples after field-cooling from above Tc. These are consistent with those seen in systems with competing repulsions on disparate length scales, and remarkably similar structures are reproduced in dirty two band Ginzburg-Landau calculations, where the simulation parameters have been defined by experimental observations. This suggests that in our dirty MgB2 films, the symmetry of the vortex structures is broken by the presence of vortex repulsions with two different lengthscales, originating from the two distinct superconducting condensates. This represents an entirely new mechanism for spontaneous symmetry breaking in systems of superconducting vortices, with important implications for pinning phenomena and high current density applications.

[Vertical fractures: apropos of 2 clinical cases].

Science.gov (United States)

Félix Mañes Ferrer, J; Micò Muñoz, P; Sánchez Cortés, J L; Paricio Martín, J J; Miñana Laliga, R

1991-01-01

The aim of the study is to present a clinical review of the vertical root fractures. Two clinical cases are presented to demonstrates the criteria for obtaining a correct diagnosis of vertical root fractures.

Development of a plastic fracture methodology for nuclear systems

International Nuclear Information System (INIS)

Marston, T.U.; Jones, R.L.; Kanninen, M.F.; Mowbray, D.F.

1981-01-01

This paper describes research conducted to develop a fundamental basis for flaw tolerance assessment procedures suitable for components exhibiting ductile behavior. The research was composed of an integrated combination of stable crack growth experiments and elastic-plastic analyses. A number of candidate fracture criteria were assembled and investigated to determine the proper basis for plastic fracture mechanics assessments. The results demonstrate that many different fracture criteria can be used as the basis of a resistance curve approach to predicting stable crack growth and fracture instability. While all have some disadvantages, none is completely unacceptable. On balance, the best criteria were found to be the J-integral for initiation and limited amounts of stable crack growth and the local crack-tip opening angle for extended amounts of stable growth. A combination of the two, which may preserve the advantages of each while reducing their disadvantages, also was suggested by these results. The influence of biaxial and mixed flat/shear fracture behavior was investigated and found to not alter the basic results. Further work in the development of simplified ductile fracture analyses for routine engineering assessments of nuclear pressure vessels and piping evolving from this research is also described

Utility of the AAOS Appropriate Use Criteria (AUC) for Pediatric Supracondylar Humerus Fractures in Clinical Practice.

Science.gov (United States)

Ibrahim, Talal; Hegazy, Abdelsalam; Abulhail, Safa I S; Ghomrawi, Hassan M K

2017-01-01

The American Academy of Orthopaedic Surgeons (AAOS) recently developed an Appropriate Use Criteria (AUC) for pediatric supracondylar humerus fractures (PSHF). The AUC is intended to improve quality of care by informing surgeon decision making. The aim of our study was to cross-reference the management of operatively treated PSHF with the AAOS-published AUC. The AUC for PSHF include 220 patient scenarios, based on different combinations of 6 factors. For each patient scenario, 8 treatment options are evaluated as "appropriate," "maybe appropriate," and "rarely appropriate." We retrospectively reviewed the medical charts and radiographs of all operatively treated PSHF at our hospital from January 2013 to December 2014 and determined the appropriateness of the treatment. Over the study period, 94 children (mean age: 5.2 y; 51 male, 43 female) were admitted with PSHF and underwent a surgical procedure (type IIA: 7, type IIB: 14, type III: 70, flexion type: 3). Only 8 of the 220 scenarios were observed in our patient cohort. The most frequent scenario was represented by a type III fracture, palpable distal pulse, no nerve injury, closed soft-tissue envelope, no radius/ulna fracture, and typical swelling. Of the 94 fractures, the AUC was "appropriate" for 84 cases and "maybe appropriate" for 9 cases. There was only 1 case of "rarely appropriate" management. Closed reduction with lateral pinning and immobilization was the most prevalent treatment option (58.5%). The rate of appropriateness was not affected by the operating surgeon. However, the definition of a case as emergent had a significant impact on the rate of appropriateness. Application of the AUC to actual clinical data was relatively simple. The majority of operatively treated PSHF (89.4%) were managed appropriately. With the introduction of electronic medical charts, an AUC application becomes attractive and easy for orthopaedic surgeons to utilize in clinical practice. However, validity studies of the AUC in

Fracture-mechanical results of non-destructive testing - function, goals, methods

International Nuclear Information System (INIS)

Herter, K.H.; Kockelmann, H.; Schuler, X.; Waidele, H.

2004-01-01

Non-destructive testing provides data for fracture-mechanical analyses, e.g. defect size and orientation. On the other hand, fracture-mechanical analyses may help to define criteria for non-destructive testing, e.g. sensitivity, inspection intervals and inspection sites. The criteria applied differ as a function of the safety relevance of a component. (orig.) [de

Use of notched beams to establish fracture criteria for beryllium

International Nuclear Information System (INIS)

Mayville, R.A.

1980-01-01

The fracture of an improved form of pure beryllium was studied under triaxial tensile stresses. This state of stress was produced by testing notched beams, which were thick enough to be in a state of plane strain at the center. A plane strain, elastic-incremental plasticity finite element program was then used to determine the stress and strain distributions at fracture. A four-point bend fixture was used to load the specimens. It was carefully designed and manufactured to eliminate virtually all of the shear stresses at the reduced section of the notched beams. The unixial properties were obtained

Reconciliation of Cahn-Hilliard predictions for spinodal decomposition lengthscales in polymer blends

Science.gov (United States)

Cabral, Joao

Spinodal decomposition (SD) of partially miscible polymer blends can yield well-defined nanostructures with prescribed lengthscales and connectivity, and applications ranging from membranes and scaffolds to photovoltaics. Cahn-Hilliard-Cook (CHC) theory estimates the initial, dominant SD wavenumber to be qm =√{G''/4 k } , where G'' is the second derivative of the free energy of mixing with respect to concentration and k is a structural parameter which can be computed from the segment lengths and volumes of monomer units. Tuning G'', with quench depth into the two phase region, for instance, should thus provide a facile and precise means for designing polymeric bicontinuous structures. The fulfillment of this potential rests on the thermodynamics of available polymer systems, coarsening kinetics, as well as engineering constraints. We extensively review experimental measurements of G'' in both one- and two-phase blend systems, and critically examine the accuracy of this fundamental prediction against achievements over the past 4 decades of polymer blend demixing. Despite widespread misconceptions in detecting and describing SD, we find the CHC relation to be remarkably accurate and conclude with design considerations and limitations for polymer nanostructures via SD, reflecting on John Cahn's contributions to the field.

Assessing Impact Direction in 3-point Bending of Human Femora: Incomplete Butterfly Fractures and Fracture Surfaces,.

Science.gov (United States)

Isa, Mariyam I; Fenton, Todd W; Deland, Trevor; Haut, Roger C

2018-01-01

Current literature associates bending failure with butterfly fracture, in which fracture initiates transversely at the tensile surface of a bent bone and branches as it propagates toward the impact surface. The orientation of the resulting wedge fragment is often considered diagnostic of impact direction. However, experimental studies indicate bending does not always produce complete butterfly fractures or produces wedge fragments variably in tension or compression, precluding their use in interpreting directionality. This study reports results of experimental 3-point bending tests on thirteen unembalmed human femora. Complete fracture patterns varied following bending failure, but incomplete fractures and fracture surface characteristics were observed in all impacted specimens. A flat, billowy fracture surface was observed in tension, while jagged, angular peaks were observed in compression. Impact direction was accurately reconstructed using incomplete tension wedge butterfly fractures and tension and compression fracture surface criteria in all thirteen specimens. © 2017 American Academy of Forensic Sciences.

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

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.

Dating fractures in infants

International Nuclear Information System (INIS)

Halliday, K.E.; Broderick, N.J.; Somers, J.M.; Hawkes, R.

2011-01-01

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.

Failure Criteria for Reinforced Materials

DEFF Research Database (Denmark)

Rathkjen, Arne

Failure of materials is often characterized as ductile yielding, brittle fracture, creep rupture, etc., and different criteria given in terms of different parameters have been used to describe different types of failure. Only criteria expressing failure in terms of stress are considered in what...... place until the matrix, the continuous component of the composite, fails. When an isotropic matrix is reinforced as described above, the result is an anisotropic composite material. Even if the material is anisotropic, it usually exhibits a rather high degree of symmetry and such symmetries place...... certain restrictions on the form of the failure criteria for anisotropic materials. In section 2, some failure criteria for homogenous materials are reviewed. Both isotropic and anisotropic materials are described, and in particular the constraints imposed on the criteria from the symmetries orthotropy...

Flaw acceptance criteria taking into consideration the NDT: radiographic and ultrasonic testing. Analysis through the fracture mechanics methods

International Nuclear Information System (INIS)

Capurro, E.; Alicino, F.; Corvi, A.

1993-01-01

The present study compares and evaluates the flaw acceptance criteria of the non-destructive inspections meeting European Community standards, through the application of the fracture mechanics methods that were determined and verified by the previous activity. Some choices were made; these, however, do not change the general validity of the conclusions. Shaved full-penetration butt welds of Class 1 components making up the primary circuit were considered and the following parameters varied: standards: French, German, Italian (ASME III) and UK; material: AISI 316 and low alloy steel A 533; base material and weld metal; temperature: RT, 370 deg C for the austenitic and 260 deg C for the ferritic steel; ultrasonic and radiographic methods; defect position: surface and internal; stress condition: situations with different primary and secondary stresses. From a preliminary examination of this study it is evident that the large quantity of results available and the abundance of information contained therein make a simple and exhaustive synthesis difficult. In fact, different analyses are possible and we have, therefore, limited the research to activities to perform a comparison and a general evaluation of the acceptance criteria of the non-destructive testing. (authors). 57 refs., 25 figs., 11 tabs

Flow and fracture of alloys in the fusion environment

International Nuclear Information System (INIS)

Wolfer, W.G.

1982-01-01

The present paper examines both ductile and brittle fracture models of steels and assesses the impact of the fusion reactor environment on the fracture processes. In particular, the connections between plastic flow properties and fracture modes are reviewed for both ductile and brittle crack propagation. Highly radiation-hardened materials exhibit extreme flow location resulting in channel fracture. Physical models for this phenomon are developed and an estimate for the associated fracture toughness is given. The impact of radiation-hardening and ductility loss on fatigue crack growth is examined. Next, models describing the chemical effects on fatigue and fracture are briefly discussed. Finally, fracture design criteria are proposed for first wall structures in fusion reactors. (orig.)

Effect of combined loading on pipe flaw evaluation criteria

International Nuclear Information System (INIS)

Miura, Naoki; Chung Yeonki

1999-01-01

Considering a rational maintenance rule of Light Water Reactor piping, reliable flaw evaluation criteria are essential to determine how a detected flaw is detrimental to continuous plant operation. Ductile fracture is one of the dominant failure modes to be considered for carbon steel piping, and can be analyzed by the elastic-plastic fracture mechanics. Currently the analytical results are provided as flaw evaluation criteria using load correction factors such like the Z-factor in ASME Code Section 6. The present correction factors were conventionally determined taken a conservatism and a simplicity into account, however, the effect of internal pressure which would be an important factor under an actual plant condition was not adequately considered. Recently, a J-estimation scheme, 'LBB.ENGC' for ductile fracture analysis of circumferentially through-wall-cracked pipes subjected to combined loading was newly developed to have a better prediction with more realistic manner. This method is explicitly incorporated the contribution of both bending and tension due to internal pressure by means of the scheme compatible with an arbitrary combined loading history. In this paper, the effect of internal pressure on the flaw evaluation criteria was investigated using the new J-estimation scheme. A correction factor based on the new J-estimation scheme was compared with the present correction factors, and the predictability of the current flaw evaluation criteria was quantitatively evaluated in consideration of internal pressure. (author)

Fractures in infants and toddlers with rickets

Energy Technology Data Exchange (ETDEWEB)

Chapman, Teresa; Done, Stephen [Seattle Children' s Hospital, Department of Radiology, Seattle, WA (United States); Sugar, Naomi; Feldman, Kenneth [Seattle Children' s Hospital, Children' s Protection Program, Seattle, WA (United States); Marasigan, Joanne; Wambold, Nicolle [University of Washington, College of Arts and Sciences, Seattle, WA (United States)

2010-07-15

Rickets affects young infants and toddlers. However, there is a paucity of literature regarding the types of fractures that occur in rachitic patients. To evaluate the age of patients at which radiographically evident rickets occurs, and to characterize the age incidence and fractures that are observed in infants and toddlers with radiographically evident rickets. A retrospective study of children younger than 24 months was performed. Clinical data and radiographs were reviewed. Radiographs obtained within 1 month of the diagnosis were evaluated for the presence or absence of osteopenia, presence or absence of fraying-cupping, and presence and characterization of fractures. After exclusion criteria were applied, 45 children were included in the study. Children with rickets evident by radiograph were in the age range of 2-24 months. Fractures were present in 17.5% of the study group, exclusively in mobile infants and toddlers. Fracture types included transverse long bone fractures, anterior and anterior-lateral rib fractures, and metaphyseal fractures. All fractures occurred exclusively in patients with severe, overtly evident rickets. Fractures occur in older infants and toddlers with overt rickets and can be seen by radiograph. Fractures do not resemble high-risk non-accidental trauma fractures. (orig.)

Femoral neck fractures: A prospective assessment of the pattern ...

African Journals Online (AJOL)

OBJECTIVE: To review the pattern of femoral neck fractures, complications and outcome following fixation with Austin-Moore endoprosthesis. METHOD: A two year prospective study in patients who had fracture of the femoral neck based on strict inclusion criteria. All the patients were treated by Austin-Moore ...

Two-criteria method for fracture-mechanical analysis of pipelines - practical application and influencing parameters; Zwei-Kriterien-Verfahren zur bruchmechanischen Befundbewertung in Rohrleitungen - praktische Anwendung und Einflussgroessen

Energy Technology Data Exchange (ETDEWEB)

Beukelmann, D. [TUeV Sued Industrie Service GmbH (Germany); Doerk, O.; Wernicke, R. [TUeV Nord SysTec GmbH und Co. KG (Germany)

2006-07-01

The findings obtained in recurrent inspections as a rule are evaluated by fracture-mechanical analyses. On the basis of the results, it is decided whether a component must be repaired or if operation can continue as it is for the time being. The two-criteria method is applied as a rule because of its universal applicability. Limited ductile crack growth can be taken into account if crack resistance curves are available that can be transferred to the component in question. In the investigations presented here, the influence of the relevant initial variables, e.g. strength coefficents, fracture-mechanical material coefficients, primary and secondary stresses and the intrinsic state of stress is illustrated by exemplary calculations. Further, the safety concepts underlying the assessment are gone into. (orig.)

Methodology for plastic fracture - a progress report

International Nuclear Information System (INIS)

Wilkinson, J.P.D.; Smith, R.E.E.

1977-01-01

This paper describes the progress of a study to develop a methodology for plastic fracture. Such a fracture mechanics methodology, having application in the plastic region, is required to assess the margin of safety inherent in nuclear reactor pressure vessels. The initiation and growth of flaws in pressure vessels under overload conditions is distinguished by a number of unique features, such as large scale yielding, three-dimensional structural and flaw configurations, and failure instabilities that may be controlled by either toughness or plastic flow. In order to develop a broadly applicable methodology of plastic fracture, these features require the following analytical and experimental studies: development of criteria for crack initiation and growth under large scale yielding; the use of the finite element method to describe elastic-plastic behaviour of both the structure and the crack tip region; and extensive experimental studies on laboratory scale and large scale specimens, which attempt to reproduce the pertinent plastic flow and crack growth phenomena. This discussion centers on progress to date on the selection, through analysis and laboratory experiments, of viable criteria for crack initiation and growth during plastic fracture. (Auth.)

Evaluation of Fibular Fracture Type vs Location of Tibial Fixation of Pilon Fractures.

Science.gov (United States)

Busel, Gennadiy A; Watson, J Tracy; Israel, Heidi

2017-06-01

Comminuted fibular fractures can occur with pilon fractures as a result of valgus stress. Transverse fibular fractures can occur with varus deformation. No definitive guide for determining the proper location of tibial fixation exists. The purpose of this study was to identify optimal plate location for fixation of pilon fractures based on the orientation of the fibular fracture. One hundred two patients with 103 pilon fractures were identified who were definitively treated at our institution from 2004 to 2013. Pilon fractures were classified using the AO/OTA classification and included 43-A through 43-C fractures. Inclusion criteria were age of at least 18 years, associated fibular fracture, and definitive tibial plating. Patients were grouped based on the fibular component fracture type (comminuted vs transverse), and the location of plate fixation (medial vs lateral) was noted. Radiographic outcomes were assessed for mechanical failures. Forty fractures were a result of varus force as evidenced by transverse fracture of the fibula and 63 were due to valgus force with a comminuted fibula. For the transverse fibula group, 14.3% mechanical complications were noted for medially placed plate vs 80% for lateral plating ( P = .006). For the comminuted fibular group, 36.4% of medially placed plates demonstrated mechanical complications vs 16.7% for laterally based plates ( P = .156). Time to weight bearing as tolerated was also noted to be significant between groups plated medially and laterally for the comminuted group ( P = .013). Correctly assessing the fibular component for pilon fractures provides valuable information regarding deforming forces. To limit mechanical complications, tibial plates should be applied in such a way as to resist the original deforming forces. Level of Evidence Level III, comparative study.

Cervical spine fractures in elderly patients with hip fracture after low-level fall: an opportunity to refine prehospital spinal immobilization guidelines?

Science.gov (United States)

Boland, Lori L; Satterlee, Paul A; Jansen, Paul R

2014-02-01

Conventional prehospital spine-assessment approaches based on low index of suspicion and mechanism of injury (MOI) result in the liberal application of spinal immobilization in trauma patients. A painful distracting injury (DI), such as a suspected hip fracture, historically has been a sufficient condition for immobilization, even in an elderly patient who suffers a simple fall from standing and exhibits no other risk factors for spinal injury. Because the elderly are at increased risk of hip fracture from low-level falls, and are also particularly susceptible to the discomfort and morbidity associated with immobilization, the prevalence of cervical spine (c-spine) fracture in this patient population was examined. Hospital billing records were used to identify all cases of traumatic femur fracture in Minnesota (USA) in 2010-2011. Concurrent diagnosis and external cause codes were used to estimate the prevalence of c-spine fracture by age and MOI. Among 1,394 patients with femur fracture, 23 (1.7%) had a c-spine fracture. When the MOI was a fall from standing or sitting height and the patient age was ≥ 65, the prevalence dropped to 0.4% (2/565). The prevalence was similar when the definition of hip fracture additionally included pelvis fractures (0.5%; 11/2,441). Eight of the 11 patients with c-spine fracture had diagnosis codes indicative of criteria other than the DI that likely would have resulted in immobilization (eg, head injury and compromised mental status). C-spine fracture is extremely rare in elderly patients who sustain hip fracture as a result of a low-level fall, and appears to be accompanied frequently by other known predictors of spinal injury besides DI. More research is needed to determine whether conservative use of spinal immobilization may be warranted in elderly patients with hip fracture after low-level falls when the only criteria for immobilization is the distracting hip injury.

Standardizing the evaluation criteria on treatment outcomes of mandibular implant overdentures: a systematic review

Science.gov (United States)

Kim, Ha-Young; Shin, Sang-Wan

2014-01-01

PURPOSE The aim of this review was to analyze the evaluation criteria on mandibular implant overdentures through a systematic review and suggest standardized evaluation criteria. MATERIALS AND METHODS A systematic literature search was conducted by PubMed search strategy and hand-searching of relevant journals from included studies considering inclusion and exclusion criteria. Randomized clinical trials (RCT) and clinical trial studies comparing attachment systems on mandibular implant overdentures until December, 2011 were selected. Twenty nine studies were finally selected and the data about evaluation methods were collected. RESULTS Evaluation criteria could be classified into 4 groups (implant survival, peri-implant tissue evaluation, prosthetic evaluation, and patient satisfaction). Among 29 studies, 21 studies presented implant survival rate, while any studies reporting implant failure did not present cumulative implant survival rate. Seventeen studies evaluating peri-implant tissue status presented following items as evaluation criteria; marginal bone level (14), plaque Index (13), probing depth (8), bleeding index (8), attachment gingiva level (8), gingival index (6), amount of keratinized gingiva (1). Eighteen studies evaluating prosthetic maintenance and complication also presented following items as evaluation criteria; loose matrix (17), female detachment (15), denture fracture (15), denture relining (14), abutment fracture (14), abutment screw loosening (11), and occlusal adjustment (9). Atypical questionnaire (9), Visual analog scales (VAS) (4), and Oral Health Impact Profile (OHIP) (1) were used as the format of criteria to evaluate patients satisfaction in 14 studies. CONCLUSION For evaluation of implant overdenture, it is necessary to include cumulative survival rate for implant evaluation. It is suggested that peri-implant tissue evaluation criteria include marginal bone level, plaque index, bleeding index, probing depth, and attached gingiva

Overtreatment of displaced midshaft clavicle fractures

DEFF Research Database (Denmark)

Ban, Ilija; Nowak, Jan; Virtanen, Kaisa

2016-01-01

Background and purpose - The best treatment for displaced clavicle fractures has been debated for decades. Operative treatment has become more common. However, several randomized trials comparing non-operative and operative treatment have not shown any compelling evidence in favor of surgery. We...... identified the preferred treatment of displaced midshaft clavicle fractures at public hospitals in 3 countries in Scandinavia. Patients and methods - A purpose-made multiple-choice questionnaire in English was sent to all public hospitals in Denmark, Sweden, and Finland. This was addressed to the orthopedic...... surgeon responsible for treatment of clavicle fractures, and completed questionnaires were obtained from 85 of 118 hospitals. Results - In the 3 countries, 69 of the 85 hospitals that responded would treat displaced clavicle fractures operatively. Clear criteria for treatment allocation were used at 58...

Synthesis of industrial applications of local approach to fracture models

International Nuclear Information System (INIS)

Eripret, C.

1993-03-01

This report gathers different applications of local approach to fracture models to various industrial configurations, such as nuclear pressure vessel steel, cast duplex stainless steels, or primary circuit welds such as bimetallic welds. As soon as models are developed on the basis of microstructural observations, damage mechanisms analyses, and fracture process, the local approach to fracture proves to solve problems where classical fracture mechanics concepts fail. Therefore, local approach appears to be a powerful tool, which completes the standard fracture criteria used in nuclear industry by exhibiting where and why those classical concepts become unvalid. (author). 1 tab., 18 figs., 25 refs

Fractures of the talus: experience of two level 1 trauma centers.

Science.gov (United States)

Elgafy, H; Ebraheim, N A; Tile, M; Stephen, D; Kase, J

2000-12-01

Fifty-eight patients with 60 talar fractures were retrospectively reviewed. There were 39 men and 19 women. The age average was 32 (range, 14-74). Eighty six percent of the patients had multiple injuries. The most common mechanism of injury was a motor vehicle accident. Twenty-seven (45%) of the fractures were neck, 22 (36.7%) process, and 11 (18.3%) body. Forty-eight fractures had operative treatment and 12 had non-operative management. The average follow-up period was 30 months (range, 24-65). Thirty-two fractures (53.3%) developed subtalar arthritis. Two patients had subsequent subtalar fusion. Fifteen fractures (25%) developed ankle arthritis. None of these patients required ankle fusion. Fractures of the body of the talus were associated with the highest incidence of degenerative joint disease of both the subtalar and ankle joints. Ten fractures (16.6%) developed avascular necrosis (AVN), only one of which had subsequent slight collapse. Avascular necrosis occurred mostly after Hawkins Type 3 and 2 fractures of the talar neck. Three rating scores were used in this series to assess the outcome: the American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score, Maryland Foot Score, and Hawkins Evaluation Criteria. The outcome was different with every rating system. However, the outcome with AOFAS Ankle-Hindfoot Score and Hawkins Evaluation Criteria were almost equivalent. Assessment with the three rating scores showed that the process fractures had the best results followed by the neck and then the body fractures.

Fracture analysis of concrete gravity dam under earthquake induced ...

African Journals Online (AJOL)

In this paper, seismic fracture behavior of the concrete gravity dam using finite element (2D) theory has been studied. Bazant model which is non-linear fracture mechanics criteria as a measure of growth and smeared crack was chosen to develop profiles of the crack. Behavior of stress - strain curves of concrete as a ...

Advanced composite structures. [metal matrix composites - structural design criteria for spacecraft construction materials

Science.gov (United States)

1974-01-01

A monograph is presented which establishes structural design criteria and recommends practices to ensure the design of sound composite structures, including composite-reinforced metal structures. (It does not discuss design criteria for fiber-glass composites and such advanced composite materials as beryllium wire or sapphire whiskers in a matrix material.) Although the criteria were developed for aircraft applications, they are general enough to be applicable to space vehicles and missiles as well. The monograph covers four broad areas: (1) materials, (2) design, (3) fracture control, and (4) design verification. The materials portion deals with such subjects as material system design, material design levels, and material characterization. The design portion includes panel, shell, and joint design, applied loads, internal loads, design factors, reliability, and maintainability. Fracture control includes such items as stress concentrations, service-life philosophy, and the management plan for control of fracture-related aspects of structural design using composite materials. Design verification discusses ways to prove flightworthiness.

Open versus closed reduction: diacapitular fractures of the mandibular condyle.

Science.gov (United States)

Chrcanovic, Bruno Ramos

2012-09-01

The purpose of the study was to review the literature regarding the evolution of current thoughts on management of diacapitular fractures (DFs) of the mandibular condyle. An electronic search in PubMed was undertaken in March 2012. The titles and abstracts from these results were read to identify studies within the selection criteria. Eligibility criteria included studies reporting clinical series of DFs, including both animal and human studies, without date or language restrictions. The search strategy initially yielded 108 references. Twenty-eight studies were identified without repetition within the selection criteria. Additional hand-searching of the reference lists of selected studies yielded three additional papers. The current indications for open reduction and internal fixation (ORIF) of DFs described in the literature are: (a) fractures affecting the lateral condyle with reduction of mandibular height; (b) fractures in which the proximal fragment dislocates laterally out of the glenoid fossa, which cannot be reduced by closed or open treatment of another part of the mandibular fracture. The indications for conservative treatment are: (a) fractures that do not shorten the condylar height (a fracture with displacement of the medial parts of the condyle); (b) undisplaced fractures; (c) comminution of the condylar head, when the bony fragments are too small for stable fixation; and (d) fractures in children. As the temporomandibular joint disk plays an important role as a barrier preventing ankylosis, it is important to reposition the disk (if displaced/dislocated) during the surgical treatment of DFs. The lateral pterygoid muscle should never be stripped from the medially displaced fragment because its desinsertion disrupts circulation to the medial bony fragment, and also because this muscle helps to restore the muscle function after surgery. ORIF of selected DFs improves prognosis by anatomical bone and soft tissue recovery when combined with physical

Low-intensity pulsed ultrasound: Fracture healing

Directory of Open Access Journals (Sweden)

Mundi Raman

2009-01-01

Full Text Available Annually, millions of people across the world are inflicted with bone fracture injuries. Untimely healing is a significant burden in terms of socioeconomic costs, personal costs, and patients′ quality of life. Low-intensity pulsed ultrasound (LIPUS has gained much attention as a potential adjunctive therapy for accelerating fresh fracture healing, but its efficacy remains controversial. This paper is presented in two parts a literature review followed by a systematic review. The literature review highlights the physiology of fracture healing and the influence LIPUS exerts on cells and molecules involved in this healing process. In part two, we present a systematic review of randomized controlled trials (RCTs assessing the clinical effectiveness of LIPUS in accelerating the time to fracture healing. The electronic databases we searched for the systematic review are as follows: MEDLINE (from 1996 to November 2008, EMBASE (from 1996 to November 2008, and Healthstar (from 1966 to October 2008. A two-step screening process was used to assess the eligibility of studies yielded by our search. The first step was a review of titles and abstracts for the selection of studies that met the following criteria: (i inclusion of skeletally mature patients with a fresh fracture, (ii a minimum of two treatment arms with at least one arm receiving LIPUS treatment and another arm receiving placebo, (iii random allocation of patients to the different treatment arms, (iv radiological assessment of time to fracture healing, and (v publication in the English language. In the second step, selected articles were reviewed in full text. Eligible trials were all scored independently by two reviewers for methodological reporting quality using the 15-item CLEAR NPT checklist (Checklist to Evaluate the Report of a Nonpharmacological Trial. We identified a total of seventy seven studies, nine of which met our inclusion criteria after the initial screening. Of these nine

Protecting against failure by brittle fracture in ferritic steel shipping containers

International Nuclear Information System (INIS)

Schwartz, M.W.; Langland, R.T.

1983-01-01

The possible use of ferritic steels for the containment structure of shipping casks has motivated the development of criteria for assuring the integrity of these casks under both normal and hypothetical accident conditions specified in Part 71 of the Code of Federal Regulations. The US Nuclear Regulatory Commission Regulation Guide 7.6 provides design criteria for preventing ductile failure steel shipping containers. The research described in this paper deals with criteria for preventing brittle fracture of ferritic steel shipping containers. Initially guidelines were developed for ferritic steel up to four inches thick (I). This was followed by an investigation of various criteria that might be used for monolithic thick walled casks greater than four inches thick (2). Three categories of safety are identified in the design of shipping containers. Category I, the highest level of safety, is appropriate for containment systems for spent nuclear fuel and high level waste transport packaging. In Category I, containers are designed to the highest level of safety and brittle fracture is essentially not possible. Categories II and III represent levels of safety commensurate with the consequences of release of lower levels of radioactivity. In these latter categories, consideration of factors contributing to brittle fracture, good engineering practice, and careful selection of material make brittle fracture unlikely under environmental conditions encountered during shipping. This paper will deal primarily with Category I containers. The guidelines for Category II and III containers are fully described elsewhere. 5 references, 10 figures, 3 tables

Effective secondary fracture prevention: implementation of a global benchmarking of clinical quality using the IOF Capture the Fracture® Best Practice Framework tool.

Science.gov (United States)

Javaid, M K; Kyer, C; Mitchell, P J; Chana, J; Moss, C; Edwards, M H; McLellan, A R; Stenmark, J; Pierroz, D D; Schneider, M C; Kanis, J A; Akesson, K; Cooper, C

2015-11-01

Fracture Liaison Services are the best model to prevent secondary fractures. The International Osteoporosis Foundation developed a Best Practice Framework to provide a quality benchmark. After a year of implementation, we confirmed that a single framework with set criteria is able to benchmark services across healthcare systems worldwide. Despite evidence for the clinical effectiveness of secondary fracture prevention, translation in the real-world setting remains disappointing. Where implemented, a wide variety of service models are used to deliver effective secondary fracture prevention. To support use of effective models of care across the globe, the International Osteoporosis Foundation's Capture the Fracture® programme developed a Best Practice Framework (BPF) tool of criteria and standards to provide a quality benchmark. We now report findings after the first 12 months of implementation. A questionnaire for the BPF was created and made available to institutions on the Capture the Fracture website. Responses from institutions were used to assign gold, silver, bronze or black (insufficient) level of achievements mapped across five domains. Through an interactive process with the institution, a final score was determined and published on the Capture the Fracture website Fracture Liaison Service (FLS) map. Sixty hospitals across six continents submitted their questionnaires. The hospitals served populations from 20,000 to 15 million and were a mix of private and publicly funded. Each FLS managed 146 to 6200 fragility fracture patients per year with a total of 55,160 patients across all sites. Overall, 27 hospitals scored gold, 23 silver and 10 bronze. The pathway for the hip fracture patients had the highest proportion of gold grading while vertebral fracture the lowest. In the first 12 months, we have successfully tested the BPF tool in a range of health settings across the globe. Initial findings confirm a significant heterogeneity in service provision and

Introduction into technical application of fracture mechanics. 3. rev. ed.

International Nuclear Information System (INIS)

Heckel, K.

1991-01-01

Technical components made out of metal material are liable to be defective. Cracks are the most dangerous defects. Based on fracture mechanics methods were developed which permit to estimate the proveness of cracks to intrate fracture. The present book is restricted to the standardised methods of fracture mechanics. Theoretical foundations of various concepts aspect under the fracture mechanics are given. Experimental methods of determining material characteristics of fracture mechanics are explained in detail as a profound knowledge of testing criteria is necessary in order to be able to a characteristic to a component. This book contains the latest level of standardised methods of fracture mechanics. It is meant for advanced students and engineers working in practice. Some fully calculated examples are used as an introduction into the thinking of fracture mechanics. (orig./MM) [de

OBSERVATION AND ANALYSIS OF A PRONOUNCED PERMEABILITY AND POROSITY SCALE-EFFECT IN UNSATURATED FRACTURED TUFF

Energy Technology Data Exchange (ETDEWEB)

V. VESSELINOV; ET AL

2001-01-01

Over 270 single-hole (Guzman et al., 1996) and 44 cross-hole pneumatic injection tests (Illman et al., 1998; Illman, 1999) have been conducted at the Apache Leap Research Site (ALRS) near Superior, Arizona. They have shown that the pneumatic pressure behavior of fractured tuff at the site is amenable to analysis by methods which treat the rock as a continuum on scales ranging from meters to tens of meters, and that this continuum is representative primarily of interconnected fractures. Both the single-hole and cross-hole test results are free of skin effect. Single-hole tests have yielded estimates of air permeability at various locations throughout the tested rock volume, on a nominal support scale of about 1 m. The corresponding log permeability data exhibit spatial behavior characteristic of a random fractal and yield a kriged estimate of how these 1-m scale log permeabilities vary in three-dimensional space (Chen et al., 2000). Cross-hole tests have been analyzed by means of a three-dimensional inverse model (Vesselinov et al., 2000) in two ways: (a) by interpreting pressure records from individual borehole monitoring intervals, one at a time, while treating the rock as if it was spatially uniform; and (b) by using the inverse model to interpret pressure records from multiple tests and borehole monitoring intervals simultaneously, while treating the rock as a random fractal characterized by a power variogram. The first approach has yielded equivalent air permeabilities and air-filled porosities for a rock volume characterized by a length-scale of several tens of meters. Comparable results have been obtained by means of type-curves (Illman and Neuman, 2001). The second approach amounts to three-dimensional pneumatic tomography, or stochastic imaging, of the rock. It has yielded a high-resolution geostatistical estimate of how air permeability and air-filled porosity, defined over grid blocks having a length-scale of 1 m, vary throughout the modeled rock volume

Finite element assisted prediction of ductile fracture in sheet bulging

Science.gov (United States)

Donald, Bryan J. Mac; Lorza, Ruben Lostado; Yoshihara, Shoichiro

2017-10-01

With growing demand for energy efficiency, there is much focus on reducing oil consumption rates and utilising alternative fuels. A contributor to the solution in this area is to produce lighter vehicles that are more fuel efficient and/or allow for the use of alternative fuel sources (e.g. electric powered automobiles). Near-net-shape manufacturing processes such as hydroforming have great potential to reduce structural weight while still maintaining structural strength and performance. Finite element analysis techniques have proved invaluable in optimizing such hydroforming processes, however, the majority of such studies have used simple predictors of failure which are usually yield criteria such as von Mises stress. There is clearly potential to obtain more optimal solutions using more advanced predictors of failure. This paper compared the Von Mises stress failure criteria and the Oyane's ductile fracture criteria in the sheet hydroforming of magnesium alloys. It was found that the results obtained from the models which used Oyane's ductile fracture criteria were more realistic than those obtained from those that used Von Mises stress as a failure criteria.

Operative Versus Conservative Management of Displaced Tibial Shaft Fracture in Adolescents.

Science.gov (United States)

Kinney, Matthew C; Nagle, David; Bastrom, Tracey; Linn, Michael S; Schwartz, Alexandra K; Pennock, Andrew T

2016-01-01

Displaced tibial shaft fractures are common in adolescent patients, yet there is no standardized management strategy. We compared surgical fixation and closed reduction and casting (CRC) of these fractures to assess treatment outcomes and determine predictors of failure. We retrospectively reviewed all patients aged 12 to 18 who presented with a displaced tibial shaft fracture that required reduction over an 8-year period. Exclusion criteria included open fractures and lack of follow-up to radiographic union or to 6 months from the index procedure. Fractures were initially treated based on surgeon preference either with CRC or with immediate intramedullary nailing. Seventy-four patients met inclusion criteria: 57 were initially managed with CRC and 17 with operative fixation. Radiographic healing was defined as bridging of 3 cortices and adequacy of final alignment was defined as 20% (odds ratio=7.8, Palignment (92.5% vs. 72.4%, P=0.10) but required longer hospitalization (5.4 vs. 1.9 d, P<0.001) and had a higher incidence of anterior knee pain (20% vs. 0%, P<0.01). There was no significant difference between groups with respect to time to healing. Treatment outcomes between initial operative fixation and closed reduction of displaced tibia fractures in adolescents are similar, but patients must be counseled about the high failure rates with CRC. Predictors of CRC failure include initial fracture displacement and the presence of a fibula fracture-these variables should be considered when selecting a treatment method. Level III-Therapeutic study.

Treatment options for unstable trochanteric fractures: Screw or helical proxima femoral nail.

Science.gov (United States)

Bajpai, Jeetendra; Maheshwari, Rajesh; Bajpai, Akansha; Saini, Sumit

2015-01-01

To compare treatment outcome of screw proximal femoral nail (PFN) system with that of a helical PFN. The study included 77 patients with closed unstable intertrochanteric fracture classified as AO 31A2&31A3, between June 2008 to August 2011. Inclusion criteria were: all mature skeletons above 50 years of age; closed unstable trochanteric fracture classified as AO 31A2&A3. Exclusion criteria were: immature skeleton, pathological fracture of any cause other than osteoporosis, inability to walk inde- pendently prior to injury. Patients were randomized to 2 treatment groups based on admission sequence. Forty patients were treated with screw PFN and thirty seven were treated with helical PFN. Both groups were similar in respect of time of surgery, blood loss and functional assessment and duration of hospitalization. In screw PFN group 2 patients had superficial wound infection, 1 patient had persistent hip pain and 1 patient had shortening>1 cm buttrochanteric fractures even in Indian patients where the bones are narrow and neck diameter is small. It is an implant of choice for osteoporotic and unstable trochanteric fractures.

Dynamic fracture of high-strength metallic alloys: experiments and modelling

OpenAIRE

Pérez Martín, María Jesús

2017-01-01

Fracture toughness is a property which describes the ability of a material containing a crack to resist fracture. Such a characteristic is one of the most important properties for describing the failure criteria of materials and may be a function of loading rate and temperature. Therefore, in the case of materials that may be subjected to dynamic loads or extreme conditions, it is crucial to be aware of the evolution of their fracture behaviour with such variables. The main objective of t...

EVALUATION OF RESULTS IN FRACTURES OF BOTH BONES FOREARM TREATED WITH DYNAMIC COMPRESSION PLATING

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Sindhuja G

2017-06-01

Full Text Available BACKGROUND The anatomical alignment of the bones, the length, the radial bow, and axis should be restored for a good functional outcome. Conservative treatment has resulted in malunion, non-union, synostosis and ultimately poor functional outcome. Internal fixation helps in perfect reduction of fracture fragments in anatomical position by rigid fixation and early mobilisation, the normal functions of the hand can be re-achieved at the earliest. This study has been taken up to evaluate the results of open reduction and internal fixation of the fractures of BBFA with DCP in adults and its advantages and complications. In this study, the rate and time taken for union, the complication, the functional results in terms of forearm rotation and wrist and elbow movements are evaluated. MATERIALS AND METHODS This study includes treatment of 20 cases of fracture of both bones of forearm by open reduction and internal fixation with 3.5 mm DCP from August 2013 to August 2015 at Department of Orthopaedics at Konaseema Institute of Medical Sciences, Amalapuram. Follow-up was done up to September 2015. This is a prospective time bound study. Sample size - 20 patients. Inclusion Criteria- 1. Simple fractures. 2. Open fractures-Gustilo and Anderson type I and type II. 3. Age criteria = 15 to 70 years, both males and females. Exclusion Criteria- 1. Age criteria 0 to 14 years & > 70 years. 2. Radiologically proven segmental fractures and isolated forearm bone fractures. 3. Pathological fracture. 4. Gustilo and Anderson type III. 5. Patient not willing for surgery. 6. Patient unfit for surgery. RESULTS The present study consists of 20 cases of fracture both bones of the forearm. All the cases were openly reduced and internally fixed with 3.5 mm DCP. The study period was from August 2013 to September 2015. The age of these patients ranged from 15-70 years with fracture being most common in 3 rd decade and an average age of 31 years. CONCLUSION Use of separate

The impact of different aperture distribution models and critical stress criteria on equivalent permeability in fractured rocks

DEFF Research Database (Denmark)

Bisdom, Kevin; Bertotti, Giovanni; Nick, Hamid

2016-01-01

Predicting equivalent permeability in fractured reservoirs requires an understanding of the fracture network geometry and apertures. There are different methods for defining aperture, based on outcrop observations (power law scaling), fundamental mechanics (sublinear length-aperture scaling...... in the fraction of open fractures. For the applied stress conditions, Coulomb predicts that 50% of the network is critically stressed, compared to 80% for Barton-Bandis peak shear. The impact of the fracture network on equivalent permeability depends on the matrix hydraulic properties, as in a low...

Clinical and radiographic outcomes of femoral head fractures: excision vs. fixation of fragment in Pipkin type I: what is the optimal choice for femoral head fracture?

Science.gov (United States)

Park, Kyung-Soon; Lee, Keun-Bae; Na, Bo-Ram; Yoon, Taek-Rim

2015-07-01

In this work, we present relatively long-term results of femoral head fractures with a specific focus on Pipkin type I fractures. Fifty-nine femoral head fractures were treated according to modified Pipkin's classification as follows: type I, small fragment distal to the fovea centralis (FC); type II, large fragment distal to the FC; type III, large fragment proximal to the FC; type IV, comminuted fracture. There were 15 cases of type I, 28 of type II, 9 of type III, and 7 of type IV fractures. Conservative treatment with skeletal traction was performed in 4 type II cases, excision of the fragment in 15 type I and 10 type II cases, fixation of the fragment in 14 type II and all 9 type III cases, and total hip replacement in all 7 type IV cases. The overall clinical and radiographic outcomes were evaluated using previously published criteria, focusing on the results in Pipkin type I fractures with relatively large fragments. Based on Epstein criteria, in type II fractures, excellent or good clinical results were seen in 6 of 10 patients (60.0 %) treated by excision of the fragment and 12 of 14 patients (85.7 %) treated by internal fixation (p = 0.05). Also, excellent or good radiologic results were seen in 4 of 10 (40.0 %) patients treated by excision of the fragment and 12 of 14 (85.7 %) patients treated by internal fixation (p = 0.03). Even in Pipkin type I fractures, if the fragment is large (modified Pipkin type II), early reduction and internal fixation can produce good results.

Spartan Release Engagement Mechanism (REM) stress and fracture analysis

Science.gov (United States)

Marlowe, D. S.; West, E. J.

1984-01-01

The revised stress and fracture analysis of the Spartan REM hardware for current load conditions and mass properties is presented. The stress analysis was performed using a NASTRAN math model of the Spartan REM adapter, base, and payload. Appendix A contains the material properties, loads, and stress analysis of the hardware. The computer output and model description are in Appendix B. Factors of safety used in the stress analysis were 1.4 on tested items and 2.0 on all other items. Fracture analysis of the items considered fracture critical was accomplished using the MSFC Crack Growth Analysis code. Loads and stresses were obtaind from the stress analysis. The fracture analysis notes are located in Appendix A and the computer output in Appendix B. All items analyzed met design and fracture criteria.

Intracellular calcium signals display an avalanche-like behavior over multiple lengthscales.

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Lucía eLopez

2012-09-01

Full Text Available Many natural phenomena display "self-organized criticality'' (SOC. This refers to spatially extended systems for which patterns of activity characterized by different lengthscales can occur with a probability density that follows a power law with pattern size. Differently from power laws at phase transitions, systems displaying SOC do not need the tuning of an external parameter. Here we analyze intracellular calcium Ca2+ signals, a key component of the signaling toolkit of almost any cell type. Ca2+ signals can either be spatially restricted (local or propagate throughout the cell (global. Different models have suggested that the transition from local to global signals is similar to that of directed percolation. Directed percolation has been associated, in turn, to the appearance of self-organized criticality. In this paper we discuss these issues within the framework of simple models of Ca2+ signal propagation. We also analyze the size distribution of local signals ("puffs'' observed in immature Xenopus Laevis oocytes. The puff amplitude distribution obtained from observed local signals is not Gaussian with a noticeable fraction of large size events. The experimental distribution of puff areas in the spatio-temporal record of the image has a long tail that is approximately log-normal. The distribution can also be fitted with a power law relationship albeit with a smaller goodness of fit. The power law behavior is encountered within a simple model that includes some coupling among individual signals for a wide range of parameter values. An analysis of the model shows that a global elevation of the Ca2+ concentration plays a major role in determining whether the puff size distribution is long-tailed or not. This suggests that Ca2+-clearing from the cytosol is key to determine whether IP3-mediated Ca2+ signals can display a SOC-like behavior or not.

The use of MRI and CT in Imaging Occult Hip Fractures

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Obadă B.

2014-11-01

Full Text Available Diagnosis of hip fractures is particularly important due to the high dependence on the integrity of this structure for people to function in their daily lives. Left unrecognized, patients face increasing morbidity and mortality as time from the original injury lengthens. A delay of just 2 days in surgical treatment for an acute hip fracture doubles mortality. In addition, an unrecognized non-displaced fracture may displace, requiring surgery of much higher risk. This may be part of the reason that the most frequent lawsuit against Emergency Physicians is for missed orthopedic injury. We reviewed the use of MRI and CT for occult hip fractures (OHF detection at a major urban trauma unit. Our study is a retrospective review. Inclusion criteria: all patients presenting to the Emergency Clinical Hospital of Constanta with a suspected, posttraumatic, occult hip fracture, over a 5 years period were included. All patients had negative initial radiographs and underwent further imaging with either CT or MRI. A total of 185 cases meeting the inclusion criteria were identified. 72 occult hip fractures were detected with both imaging modalities. Although MRI certainly enables greater image detail, in our experience both modalities are able to provide satisfactory fracture characterization. The choice of imaging should be determined by availability and indication. MRI provides superior imaging of soft tissue but is less sensitive for degenerative changes in presence of bone edema.

Epidural Analgesia after Rib Fractures.

Science.gov (United States)

Zaw, Andrea A; Murry, Jason; Hoang, David; Chen, Kevin; Louy, Charles; Bloom, Matthew B; Melo, Nicolas; Alban, Rodrigo F; Margulies, Daniel R; Ley, Eric J

2015-10-01

Pain associated with rib fractures impairs respiratory function and increases pulmonary morbidity. The purpose of this study was to determine how epidural catheters alter mortality and complications in trauma patients. We performed a retrospective study involving adult blunt trauma patients with moderate-to-severe injuries from January 1, 2004 to December 31, 2013. During the 10-year period, 526 patients met the inclusion criteria; 43/526 (8%) patients had a catheter placed. Mean age of patients with epidural catheter (CATH) was higher compared with patients without epidural catheter (NOCATH) (54 vs 48 years, P = 0.021), Injury Severity Score was similar (26 CATH vs 27 NOCATH, P = 0.84), and CATH had higher mean rib fractures (7.4 vs 4.1, P ribs fractured. The epidural cohort had longer hospital LOS and decreased mortality. In contrast to other studies, DVT rates were increased in patients who received epidural catheters.

Sliding contact fracture of dental ceramics: Principles and validation

Science.gov (United States)

Ren, Linlin; Zhang, Yu

2014-01-01

Ceramic prostheses are subject to sliding contact under normal and tangential loads. Accurate prediction of the onset of fracture at two contacting surfaces holds the key to greater long-term performance of these prostheses. In this study, building on stress analysis of Hertzian contact and considering fracture criteria for linear elastic materials, a constitutive fracture mechanics relation was developed to incorporate the critical fracture load with the contact geometry, coefficient of friction and material fracture toughness. Critical loads necessary to cause fracture under a sliding indenter were calculated from the constitutive equation, and compared with the loads predicted from elastic stress analysis in conjunction with measured critical load for frictionless normal contact—a semi-empirical approach. The major predictions of the models were calibrated with experimentally determined critical loads of current and future dental ceramics after contact with a rigid spherical slider. Experimental results conform with the trends predicted by the models. PMID:24632538

Safety of definitive in-theater repair of facial fractures.

Science.gov (United States)

Lopez, Manuel A; Arnholt, Jonathan L

2007-01-01

To determine the safety of definitive in-theater facial fracture repair on American military personnel wounded during Operation Iraqi Freedom. A retrospective review of all patients with head and neck trauma treated at the 322nd Expeditionary Medical Group/Air Force Theater Hospital, Balad Air Base, Iraq, from May 7, 2005, through September 18, 2005, was performed. This study focused on the outcomes of wounded American military personnel whose facial fractures were definitively repaired in theater. The criteria used to determine candidacy for definitive in-theater facial fracture repair on American military personnel were (1) the fracture site was exposed through either a soft tissue wound or because of an adjacent surgical approach, (2) treatment would not delay evacuation from theater, and (3) treatment would allow the military member to remain in theater. From May 2005 to September 2005, 207 patients were taken to the operating room and required 388 procedures. A total of 175 patients (85%) were operated on for traumatic injuries, and 52 of these patients required open reduction and internal fixation (ORIF) of a facial fracture. Of the 52 patients who underwent an ORIF, 17 were American military personnel. Of the 17 American patients who were definitively treated for their facial fractures in theater, 16 were contacted and/or followed up on the global military medical database. None of these patients developed an Acinetobacter baumannii infection or had a complication caused by the definitive in-theater ORIF. The range of follow-up was 2 months to 11 months, with a mean of 8.3 months. Definitive repair of facial fractures with ORIF on American military personnel in theater is advised when the aforementioned criteria are observed. An otolaryngologist is a crucial member of the head and neck trauma team.

Assessment of fracture toughness of structural steels

Energy Technology Data Exchange (ETDEWEB)

Gomes Junyor, José Onésimo; Faria, Stéfanno Bruno; Rocha, Nirlando Antônio; Reis, Emil; Vilela, Jefferson José, E-mail: ze_onezo@hotmail.com, E-mail: sbrunofaria@gmail.com, E-mail: nar@cdtn.br, E-mail: emilr@cdtn.br, E-mail: jjv@cdtn.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Centro Universitário de Belo Horizonte (UNIBH), MG (Brazil); Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-11-01

The fracture toughness parameters are applied to estimate the lifetime of mechanical components and define the criteria of safe failure and tolerable damages. This information allows equipment to be used longer with a high degree of safety. These techniques are applied in the Leak-Before-Break (LBB) concept that is accepted for designing the piping system of the primary circuit of the pressurized water reactor (PWR). In this work, fracture toughness tests such as J{sub IC} and CTOD were performed on some structural steels. The fracture toughness parameters were determined using SE(B) and C(T) test specimens. The fracture toughness values for the same material varied according to the type specimen. The parameter δ{sub 1c} showed different values when it was calculated using the ASTM E1820 standard and using the BS 7448: Part 1 standard. These results indicate that procedures of these standards need to be improved. Two systems with different sensitivity in the force measurement were used that showed similar results for toughness fracture but the dispersion was different. (author)

The Place of Ultrasonography in the Evaluation of Rib Fractures

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Fulya Bakılan

2015-12-01

Full Text Available Objective: The aim of this study was to investigate whether ultrasonography is superior to chest x-ray in detecting rib fractures in patients with minor blunt chest trauma and chest pain. Materials and Methods: Ultrasonography findings of 32 patients with minor blunt chest trauma showing no evidence of a rib fracture on anteroposterior chest x-rays, were documented. Presence of cortical discontinuities, acoustic shadows, reverberation artifacts, and hematoma by ultrasonography was proposed as the diagnostic criteria for detecting the rib fracture. Results: Rib fracture was detected in 20 patients (62.5% according to ultrasonography results. A mildly displaced fracture was detected in 7 patients (35%, hematoma was detected in 3 patients (15% and multiple fractures (in 5th, 6th, 7th, and 8th ribs were detected in 1 patient (5%. Conclusion: The results of our study showed that ultrasonography is superior to chest x-ray, in detecting rib fractures.

Study on interaction between induced and natural fractures by extended finite element method

Science.gov (United States)

Xu, DanDan; Liu, ZhanLi; Zhuang, Zhuo; Zeng, QingLei; Wang, Tao

2017-02-01

Fracking is one of the kernel technologies in the remarkable shale gas revolution. The extended finite element method is used in this paper to numerically investigate the interaction between hydraulic and natural fractures, which is an important issue of the enigmatic fracture network formation in fracking. The criteria which control the opening of natural fracture and crossing of hydraulic fracture are tentatively presented. Influence factors on the interaction process are systematically analyzed, which include the approach angle, anisotropy of in-situ stress and fluid pressure profile.

Fracture behavior of short circumferentially surface-cracked pipe

International Nuclear Information System (INIS)

Krishnaswamy, P.; Scott, P.; Mohan, R.

1995-11-01

This topical report summarizes the work performed for the Nuclear Regulatory Comniission's (NRC) research program entitled ''Short Cracks in Piping and Piping Welds'' that specifically focuses on pipes with short, circumferential surface cracks. The following details are provided in this report: (i) material property deteminations, (ii) pipe fracture experiments, (iii) development, modification and validation of fracture analysis methods, and (iv) impact of this work on the ASME Section XI Flaw Evaluation Procedures. The material properties developed and used in the analysis of the experiments are included in this report and have been implemented into the NRC's PIFRAC database. Six full-scale pipe experiments were conducted during this program. The analyses methods reported here fall into three categories (i) limit-load approaches, (ii) design criteria, and (iii) elastic-plastic fracture methods. These methods were evaluated by comparing the analytical predictions with experimental data. The results, using 44 pipe experiments from this and other programs, showed that the SC.TNP1 and DPZP analyses were the most accurate in predicting maximum load. New Z-factors were developed using these methods. These are being considered for updating the ASME Section XI criteria

Status report on experiments and modelling of the cleavage fracture behaviour of F82Hmod using local fracture grid. Task TTMS-005

International Nuclear Information System (INIS)

Riesch-Oppermann, H.; Walter, M.

2001-09-01

Within the European Fusion Technology Programme framework, a fracture mechanics description of the material behaviour in the ductile to brittle transition-regime is developed using local fracture criteria. Based on experimental results using axisymmetrically notched and pre-cracked specimens together with a numerical stress analysis at fracture load, a statistical evaluation of cleavage fracture parameters can be performed along the lines described in various code schemes such as the British Energy R6-Code or the ESIS P6 procedure. The report contains results of the experimental characterization of the deformation and fracture behaviour of the fusion candidate RAFM steel variant F82Hmod, details and background of the numerical procedure for cleavage fracture parameter determination as well as additional statistical inference methods for transferability analysis. Fractographic results give important information about fracture mode and fracture origin sites and their location. Numerical prediction of fracture origin distribution is an important tool for transferability assessment. Future issues comprise constraint effect and ductile damage as well as incorporation of irradiation effects, which are topically addressed. The methodology developed and described in the present report will be applied to characterize material behaviour of future RAFM variants as the EUROFER 97, for which analysis is currently under way. (orig.)

The pattern and prevalence of vertebral artery injury in patients with cervical spine fractures

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Farzanah Ismail

2013-06-01

Method: A retrospective review of patients who had undergone CTA of the vertebral arteries was undertaken. Reports were reviewed to determine which patients met the inclusion criteria of having had both cervical spine fractures and CTA of the vertebral arteries. Images of patients who met the inclusion criteria were analysed by a radiologist. Results: The prevalence of vertebral artery injury was 33%. Four out of the 11 patients who had vertebral artery injury, had post-traumatic spasm of the artery, with associated thrombosis or occlusion of the vessel. In terms of blunt carotid vertebral injury (BCVI grading, most of the patients sustained grade IV injuries. Four patients who had vertebral artery injury had fractures of the upper cervical vertebrae, i.e. C1 to C3. Fifteen transverse process fractures were associated with vertebral artery injury. No vertebral artery injury was detected in patients who had facet joint subluxations. Conclusion: Patients with transverse process fractures of the cervical spine and upper cervical vertebral body fractures should undergo CTA to exclude vertebral artery injury.

Probabilistic fracture mechanics analysis of reactor vessel for pressurized thermal shock: the effect of residual stress and fracture toughness

International Nuclear Information System (INIS)

Jung, Sung Gyu; Jin, Tae Eun; Jhung, Myung Jo; Choi, Young Hwan

2003-01-01

The structural integrity of the reactor vessel with the approaching end of life must be assured for pressurized thermal shock. The regulation specifies the screening criteria for this and requires that specific analysis be performed for the reactor vessel which is anticipated to exceed the screening criteria at the end of plant life. In case the screening criteria is exceeded by the deterministic analysis, probabilistic analysis must be performed to show that failure probability is within the limit. In this study, probabilistic fracture mechanics analysis of the reactor vessel for pressurized thermal shock is performed and the effects of residual stress and master curve on the failure probability are investigated

Prediction of forming limit in hydro-mechanical deep drawing of steel sheets using ductile fracture criterion

Science.gov (United States)

Oh, S.-T.; Chang, H.-J.; Oh, K. H.; Han, H. N.

2006-04-01

It has been observed that the forming limit curve at fracture (FLCF) of steel sheets, with a relatively higher ductility limit have linear shapes, similar to those of a bulk forming process. In contrast, the FLCF of sheets with a relatively lower ductility limit have rather complex shapes approaching the forming limit curve at neck (FLCN) towards the equi-biaxial strain paths. In this study, the FLCFs of steel sheets were measured and compared with the fracture strains predicted from specific ductile fracture criteria, including a criterion suggested by the authors, which can accurately describe FLCFs with both linear and complex shapes. To predict the forming limit for hydro-mechanical deep drawing of steel sheets, the ductile fracture criteria were integrated into a finite element simulation. The simulation, results based on the criterion suggested by authors accurately predicted the experimetal, fracture limits of steel sheets for the hydro-mechanical deep drawing process.

Estimation of the controlling stress in creep fracture

International Nuclear Information System (INIS)

Henderson, J.; Ferguson, F.R.

1975-01-01

The implementation of correct criterion in creep design, has been shown to be of fundamental significance in the assessment of component life. The present report considers the problem of the means whereby the criterion may be derived for a particular metal without the availability of sophisticated complex-stress testing equipment and procedures such as the combined tension and torsion tests on thin walled tubular specimens employed in the earlier fundamental researches on the subject. By investigating a wide spectrum of engineering metals it was established that for homogeneous stress conditions two criteria appeared to be sufficient to cover all the metals studied for complex-stress creep fracture, either the maximum principal stress or the octahedral shear stress criterion. Further, it was found that those metals which developed random and continuous cracking during creep were controlled with respect to fracture time by the maximum principal stress, while metals which showed virtually no cracking were governed by the octahedral shear stress or second order invariant. The physical nature of the final fracture (transcrystalline or inter-crystalline), contrary to considerable current concepts, was found to be unrelated to which criterion was operative. Having reduced the possible fracture criteria to two, it only remained to develop a simple test method exploiting this finding to achieve the precise identification for a particular metal. Seven metals including aluminium, copper, titanium, cast iron and three steels have been investigated in the present report at temperatures where creep conditions are operative. The results have shown that the method leads to sufficiently accurate prediction of the complex stress creep fracture criterion for the metals studied

Petrous bone fracture: a virtual trauma analysis.

Science.gov (United States)

Montava, Marion; Deveze, Arnaud; Arnoux, Pierre-Jean; Bidal, Samuel; Brunet, Christian; Lavieille, Jean-Pierre

2012-06-01

The temporal bone shields sensorineural, nervous, and vascular structures explaining the potential severity and complications of trauma related to road and sport accidents. So far, no clear data are available on the exact mechanisms involved for fracture processes. Modelization of structures helps to answer these concerns. Our objective was to design a finite element model of the petrous bone structure to modelize temporal bone fracture propagation in a scenario of lateral impact. A finite element model of the petrous bone structure was designed based on computed tomography data. A 7-m/s lateral impact was simulated to reproduce a typical lateral trauma. Results of model analysis was based on force recorded, stress level on bone structure up to induce a solution of continuity of the bony structure. Model simulation showed that bone fractures follow the main axes of the petrous bone and occurred in a 2-step process: first, a crush, and second, a massive fissuration of the petrous bone. The lines of fracture obtained by simulation of a lateral impact converge toward the middle ear region. This longitudinal fracture is located at the mastoid-petrous pyramid junction. Using this model, it was possible to map petrous bone fractures including fracture chronology and areas of fusion of the middle ear region. This technique may represent a first step to investigate the pathophysiology of the petrous bone fractures, aiming to define prognostic criteria for patients' care.

Association between cervical spine and skull-base fractures and blunt cerebrovascular injury

Energy Technology Data Exchange (ETDEWEB)

Buch, Karen; Nguyen, Thanh; Norbash, Alex; Mian, Asim [Boston University School of Medicine, Department of Radiology, Boston Medical Center, Boston, MA (United States); Mahoney, Eric; Burke, Peter [Boston University School of Medicine, Department of Surgery, Boston Medical Center, Boston, MA (United States); Libby, Brandon; Calner, Paul [Boston University School of Medicine, Department of Emergency Medicine, Boston Medical Center, Boston, MA (United States)

2016-02-15

Blunt cerebrovascular injuries (BCVI) are associated with high morbidity and mortality and can lead to neurological deficits. The established criteria for patients undergoing CT angiography (CTA) for BCVI are broad, and can expose patients to radiation unnecessarily. This study aimed to examine the prevalence of BCVI in patients on CTA and determine presentations associated with the highest rates of BCVI. With IRB approval, patients were selected for CTA screening for BCVI according to a predefined set of criteria at our hospital between 2007 and 2010. Patients were identified from our institution's trauma database. CTAs were retrospectively reviewed for BCVI including vasospasm and dissection. Electronic medical records were reviewed for clinical presentation and hospital course. Of 432 patients, vasospasm (n = 10) and/or dissection (n = 36) were found in 46 patients (10.6 %). BCVI was associated with cervical spine and/or skull-base fracture in 40/46 patients (87 %, P < 0.0001). Significant correlations were seen between dissection and fracture in 31/36 patients (86.2 %, p < 0.0001) and between BCVI and both neurological deficits and fractures (27/44, P < 0.0001). BCVI was significantly associated with cervical and/or skullbase fractures and neurological deficits with coexistent fractures. Patients with these injuries should be prioritized for rapid CTA evaluation for BCVI. (orig.)

Aluminum toxicity in dialysis patients: Radiographic findings and establishment of biopsy-sparing criteria

International Nuclear Information System (INIS)

Kriegshauser, J.S.; Swee, R.G.; McCarthy, J.T.; Hauser, M.F.

1986-01-01

Aluminum toxicity in dialysis patients currently requires bone biopsy for diagnosis. The authors retrospectively reviewed the findings in 63 dialysis patients who had undergone bone biopsies. In 30 patients biopsies were negative for aluminum toxicity and in 33 patients biopsies were positive. In 17 of the 30 biopsy-negative patients, absence of aluminum toxicity could be predicted by a high parathyroid hormone (iPTH) level (>200 μEq/ml) and fewer than three fractures, or by the presence of osteosclerosis on radiographs. No biopsy-positive patients met these criteria (P < .001). In 16 of 33 biopsy-positive patients aluminum toxicity could be predicted by a low iPTH level (<500 μEq/ml) and more than three fractures. No biopsy-negative patient met these criteria (P < .001). Thus, based on the criteria we have identified, 52.4% of the patients could have been spared biopsy

Treatment of proximal humerus fractures with locking plates: a systematic review.

Science.gov (United States)

Thanasas, Christos; Kontakis, George; Angoules, Antonios; Limb, David; Giannoudis, Peter

2009-01-01

Locking plates with special configuration for the anatomic region of the proximal humerus have been introduced recently to address the difficulties of stabilizing proximal humeral fractures. The purpose of this study was to carry out a systematic review of the literature on the efficacy and early to medium term functional results of locking plates for stabilization of proximal humeral fractures. Using the PubMed database, a systematic review of the English and German literature was carried out in order to assess the efficacy and complications related to the use of these plates and the patients' functional outcome, using the key words "locking plates proximal humeral fractures," "angular stability plates proximal humeral fractures," "PHILOS plate," and "LPHP plate." Our criteria for eligibility were clinical studies with more than ten cases followed-up, adult patients, and adequate data provided at least in terms of implant related complications. Articles written in English and German language were included. Exclusion criteria were: studies dealing exclusively with 2-part fractures (since this category has a more favorable outcome); experimental studies; case reports; and, literature other than English or German. Each one of the articles was evaluated for quality of the study using the Structured Effectiveness Quality Evaluation Scale (SEQES). Twelve studies including 791 patients met the inclusion criteria. Patients in these studies continued to improve up to one year, achieving a mean Constant score of 74.3. The incidence of the reported complications was: avascular necrosis 7.9%, screw cut-out 11.6% and re-operation rate 13.7%. The high incidence of cut-out may be secondary to the rigidity of the implant in combination with medial inadequate support, in cases compromised by severe underlying osteoporotic bone. Definition of indications for the use of locking plates and attention on technical aspects of applying them would help optimization of the results

Improving safety margin of LWRs by rethinking the emergency core cooling system criteria and safety system capacity

Energy Technology Data Exchange (ETDEWEB)

Lee, Youho, E-mail: euo@kaist.ac.kr; Kim, Bokyung, E-mail: bkkim2@kaist.ac.kr; NO, Hee Cheon, E-mail: hcno@kaist.ac.kr

2016-10-15

Highlights: • Zircaloy embrittlement criteria can increase to 1370 °C for CP-ECR lower than 13%. • The draft ECCS criteria of U.S. NRC allow less than 5% in power margin. • The Japanese fracture-based criteria allow around 5% in power margin. • Increasing SIT inventory is effective in assuring safety margin for power uprates. - Abstract: This study investigates the engineering compatibility between emergency core cooling system criteria and safety water injection systems, in the pursuit of safety margin increase of light water reactors. This study proposes an acceptable temperature increase to 1370 °C as long as equivalent cladding reacted calculated by the Cathcart–Pawel equation is below 13%, after an extensive literature review. The influence of different ECCS criteria on the safety margin during large break loss of coolant accident is investigated for OPR-1000 by the system code MARS-KS, implemented with the KINS-REM method. The fracture-based emergency core cooling system (ECCS) criteria proposed in this study are shown to enable power margins up to 10%. In the meantime, the draft U.S. NRC’s embrittlement criteria (burnup-sensitive) and Japanese fracture-based criteria are shown to allow less than 5%, and around 5% of power margins, respectively. Increasing safety injection tank (SIT) water inventory is the key, yet convenient, way of assuring safety margin for power increase. More than 20% increase in the SIT water inventory is required to allow 15% power margins, for the U.S. NRC’s burnup-dependent embrittlement criteria. Controlling SIT water inventory would be a useful option that could allow the industrial desire to pursue power margins even under the recent atmosphere of imposing stricter ECCS criteria for the considerable burnup effects.

Return to sports after ankle fractures: a systematic review.

Science.gov (United States)

Del Buono, Angelo; Smith, Rebecca; Coco, Manuela; Woolley, Laurence; Denaro, Vincenzo; Maffulli, Nicola

2013-01-01

This review aims to provide information on the time athletes will take to resume sports activity following ankle fractures. We systematically searched Medline (PubMED), EMBASE, CINHAL, Cochrane, Sports Discus and Google scholar databases using the combined keywords 'ankle fractures', 'ankle injuries', 'athletes', 'sports', 'return to sport', 'recovery', 'operative fixation', 'pinning', 'return to activity' to identify articles published in English, Spanish, French, Portuguese and Italian. Seven retrospective studies fulfilled our inclusion criteria. Of the 793 patients, 469 (59%) were males and 324 (41%) were females, and of the 356 ankle fractures we obtained information on, 338 were acute and 18 stress fractures. The general principles were to undertake open reduction and internal fixation of acute fractures, and manage stress fractures conservatively unless a thin fracture line was visible on radiographs. The best timing to return to sports after an acute ankle fracture is still undefined, given the heterogeneity of the outcome measures and results. The time to return to sports after an acute stress injury ranged from 3 to 51 weeks. When facing athletes with ankle fractures, associated injuries have to be assessed and addressed to improve current treatment lines and satisfy future expectancies. The best timing to return to sports after an ankle fracture has not been established yet. The ideas of the return to activity parameter and surgeon databases including sports-related information could induce research to progress.

Dynamic fracture toughness data for CASTOR registered casks

International Nuclear Information System (INIS)

Winkler, H.P.; Trubitz, P.; Pusch, G.; Warnke, E.P.; Beute, K.; Novotny, V.

2004-01-01

For the use of cast iron spherical graphite for heavy-sectioned casks for transportation and storage of radiactive materials a complete failure assessment including fracture mechanical analysis is necessary. The casks require an elaborate fracture mechanics design based on fracture mechanics evaluation. The extension of the existing code with respect to dynamic loading takes account new developments to extend the field of applications. It also includes new criteria to design these casks against operating and accident loadings. A fundamental requirement for the realisation of this standard and the calculation of admissible crack lengths of stresses under dynamic loads is the availability of fracture mechanical data. The paper presents-as a part of a large test-program-first results of dynamic fracture-toughness-investigations depending on structure and temperature. The test-program will incorporate investigations on more then 2500 specimens. The investigations that will be done include static and dynamic fracture mechanics tests, dynamic tensile and pressure-tests on different formed specimens. The temperatures and other test conditions follows the IAEA-regulations and the real service conditions. The test-program will be realised in partnership with different institutes

Medical Cost Analysis of the Osteoporotic Hip Fractures

Directory of Open Access Journals (Sweden)

Savaş Çamur

2015-12-01

Full Text Available Objective: Osteoporotic hip fractures decrease the life expectancy for 20% about 20-50% of the patients become permanently dependent in terms of walking for the rest of their life. Life expectancy is increasing in Turkey in the last 20 years. We investigated the impact of osteoporotic hip fractures which increase the morbidity and mortality on the national economy. Materials and Methods: A total of 81 patients admitted to our emergency department with the diagnosis of femur intertrochanteric fracture and femoral neck fracture between 2008 and 2012 were included in this study. We retrospectively evaluated the medical records and the medical costs of these patients from hospital information management system. Results: Of the 81 patients 32 (39.6% males and 49 (60.4% females meeting the inclusion criteria were included in this study. The mean age was 80.1 years (range, 61-103. Twenty-three (27.5% patients had femoral neck fracture and 58 (72.5% patients had intertrochanteric femur fracture. The mean length of hospital stay was 13.4 days in intertrochanteric femur fracture and 15.5 days in femoral neck fracture; average of the total days of hospitalization of all patients was 13.9 days. The average treatment cost per patient was 5,912.36 TL for intertrochanteric fractures, 5,753.00 TL for neck fractures, and 5,863.09 TL for the whole patient population. Conclusion: Hip fracture is a substantial cause of morbidity and mortality in elderly. Taking preventive measures before the fracture occurs may help to prevent this problem which has a high cost treatment and which is a substantial burden for the national economy.

Probabilistic fracture mechanics analysis of reactor vessels with low upper-shelf fracture toughness

International Nuclear Information System (INIS)

Yoon, K.K.

1993-01-01

A class of submerged-arc welds used in fabricating early reactor vessels has relatively high copper contents. Studies have shown that when such vessels are irradiated, the copper contributes to lowering the Charpy upper-shelf energy level. To address this concern, 10CFR50, Appendix G requires a fracture mechanics analysis to demonstrate an adequate margin of safety for continued service. The B and W Owners Group (B and WOG) has been accumulating J-resistance fracture toughness data for these weld metals. Based on a mathematical model derived from this B and WOG data base, the first Appendix G analysis was performed. Another important issue affecting reactor vessel integrity is pressurized thermal shock (PIS) transients. In the early 1980s, probabilistic fracture mechanics analyses were performed on a reactor vessel to determine the probability of failure under postulated accident scenarios. Results of such analyses were used by the Nuclear Regulatory Commission (NRC) to establish the screening criteria for assessing reactor vessel integrity under PTS transient loads. This paper addresses the effect of low upper-shelf toughness on the probability of failure of reactor vessels under PTS loads. Probabilistic fracture mechanics codes were modified to include the low upper-shelf toughness model used in a reference and a series of analyses was performed using plant-specific material conditions and realistic PTS scenarios. The results indicate that low upper-shelf toughness has an insignificant effect on the probability of reactor vessel failures. This is mostly due to PTS transients being susceptible to crack initiation at low temperatures and not affected by upper-shelf fracture toughness

Multiple intramedullary nailing of proximal phalangeal fractures of hand

Directory of Open Access Journals (Sweden)

Patankar Hemant

2008-01-01

Full Text Available Background: Proximal phalangeal fractures are commonly encountered fractures in the hand. Majority of them are stable and can be treated by non-operative means. However, unstable fractures i.e. those with shortening, displacement, angulation, rotational deformity or segmental fractures need surgical intervention. This prospective study was undertaken to evaluate the functional outcome after surgical stabilization of these fractures with joint-sparing multiple intramedullary nailing technique. Materials and Methods: Thirty-five patients with 35 isolated unstable proximal phalangeal shaft fractures of hand were managed by surgical stabilization with multiple intramedullary nailing technique. Fractures of the thumb were excluded. All the patients were followed up for a minimum of six months. They were assessed radiologically and clinically. The clinical evaluation was based on two criteria. 1. total active range of motion for digital functional assessment as suggested by the American Society for Surgery of Hand and 2. grip strength. Results: All the patients showed radiological union at six weeks. The overall results were excellent in all the patients. Adventitious bursitis was observed at the point of insertion of nails in one patient. Conclusion: Joint-sparing multiple intramedullary nailing of unstable proximal phalangeal fractures of hand provides satisfactory results with good functional outcome and fewer complications.

Ideal Timing of Starting Weight-Bearing After Calcaneal Insufficiency Fracture: A Case Report and Review of the Literature

OpenAIRE

Imamura; Mochizuki; Kawakami; Momohara

2016-01-01

Introduction Criteria for starting weight-bearing on the heel with a symptomatic calcaneal insufficiency fracture have not yet been reported. Case Presentation We describe a rare case of a 52-year-old woman with a calcaneal insufficiency fracture who sustained a second ipsilateral calcaneal insufficiency fracture within a short time span. The initial fracture was not evident radiographically, but was detected using magnetic resona...

The epidemiology of osteoporosis in Italian postmenopausal women according to the National Bone Health Alliance (NBHA) diagnostic criteria: a multicenter cohort study.

Science.gov (United States)

Cipriani, C; Pepe, J; Bertoldo, F; Bianchi, G; Cantatore, F P; Corrado, A; Di Stefano, M; Frediani, B; Gatti, D; Giustina, A; Porcelli, T; Isaia, G; Rossini, M; Nieddu, L; Minisola, S; Girasole, G; Pedrazzoni, M

2018-04-01

The study was aimed at evaluating the prevalence of osteoporosis, defined by BMD and the National Bone Health Alliance (NBHA) criteria, and the prevalence of clinical risk factors for fractures in Italian postmenopausal women. This is a cross-sectional, multicenter, cohort study evaluating 3247 postmenopausal women aged ≥ 50 and older in different areas of Italy in the period 2012-2014. All the participants were evaluated as far as anthropometrics; questionnaires for FRAX ® and DeFRA calculation were administered and bone mineral density was measured at lumbar spine, femoral neck and total hip by DXA. The prevalence of osteoporosis, as assessed by BMD and NBHA criteria was 36.6 and 57%, respectively. Mean ± SD values of FRAX ® and DeFRA were: 10.2 ± 7.3 and 11 ± 9.4 for major fractures, and 3.3 ± 4.9 and 3.9 ± 5.9 for hip fractures, respectively. Among clinical risk factors for fracture, the presence of previous fracture, particularly non-spine/non-hip fracture, parental history of hip fracture and current smoking were the most commonly observed. Our study showed that more that the half of postmenopausal women aged 50 and older in Italy has osteoporosis on the basis of the NBHA criteria. There is a relevant high risk of femur fracture, as assessed by the FRAX ® and DeFRA and previous fracture, parental history of hip fracture and current smoking are the most common risk factors. The data should be considered particularly in relation to the need to increase prevention strategies on modifiable risk factors and therapeutic intervention.

Model of mechanical representation of the formation of natural fractures inside a petroleum reservoir; Modele de representation mecanique de la formation des fractures naturelles d'un reservoir petrolier

Energy Technology Data Exchange (ETDEWEB)

Picard, D.

2005-09-15

The optimisation of the oil production requires a better characterisation of naturally fractured reservoirs. We consider and analyse two spatial distributions. One with systematic joints is arranged in an homogeneous way; joint spacing is linked to individual bedding thickness with propagation frequently interrupted by stratigraphic interfaces (single layer jointing). The second, so-called fracture swarms, consists in fractures clustering, where stratigraphic interfaces seem to play a minor role. The analysis is based on the singularity theory and matched asymptotic expansions method with a fine scale for local perturbations and a global one for general trends. We examine the conditions of fracture propagation that are determined herein using simultaneously two fracture criteria an energy and a stress condition. We consider two modes of loading. Usually, the joint (crack opening mode) and fracture swarm growths are explained by a first order phenomenon involving effective traction orthogonal to fracture plane. Although commonly used, this hypothesis seems unrealistic in many circumstances and may conflict with geological observations. Then, we try to describe fracture growth as a second order phenomena resulting from crack parallel compression. As far as propagation across layer interfaces is concerned, the effect of loading and geometry has been summarised in maps of fracture mechanisms, describing areas of 'step-over', 'straight through propagation' and 'crack arrest'. Fracture criteria, relative size of heterogeneities, contrast of mechanical properties between bed and layer are parameters of the problem. For fracture swarms, we present a discussion bringing out what is reasonable as a loading to justify their morphology. In particular, horizontal effective tension is unable to explain neighbouring joints. Simultaneous propagation of parallel near cracks is explained by finite width cracks growing under the influence of vertical

Progressive fracture of polymer matrix composite structures: A new approach

Science.gov (United States)

Chamis, C. C.; Murthy, P. L. N.; Minnetyan, L.

1992-01-01

A new approach independent of stress intensity factors and fracture toughness parameters has been developed and is described for the computational simulation of progressive fracture of polymer matrix composite structures. The damage stages are quantified based on physics via composite mechanics while the degradation of the structural behavior is quantified via the finite element method. The approach account for all types of composite behavior, structures, load conditions, and fracture processes starting from damage initiation, to unstable propagation and to global structural collapse. Results of structural fracture in composite beams, panels, plates, and shells are presented to demonstrate the effectiveness and versatility of this new approach. Parameters and guidelines are identified which can be used as criteria for structural fracture, inspection intervals, and retirement for cause. Generalization to structures made of monolithic metallic materials are outlined and lessons learned in undertaking the development of new approaches, in general, are summarized.

Experimental fracture healing: evaluation using radionuclide bone imaging: concise communication

International Nuclear Information System (INIS)

Gumerman, L.W.; Fogel, S.R.; Goodman, M.A.; Hanley, E.N. Jr.; Kappakas, G.S.; Rutkowski, R.; Levine, G.

1978-01-01

Radionuclide bone imaging was performed in a rabbit model to observe the course of fracture healing and to establish criteria for distinguishing nonunion and delayed healing from normal healing. Sequential gamma-camera images (with pinhole collimator) were collected and subjected to computer analysis. Five groups were established: (a) control--immobilization; (b) control--immobilization plus periosteal stripping; (c) simple fracture--osteotomy; (d) delayed union--osteotomy plus periosteal stripping; and (e) nonunion--osteotomy, periosteal stripping and polymethyl methacrylate interposed between fracture fragments. Histographic representation of absolute count rates along rabbit tibias followed a predictable pattern in the simple-fracture and delayed-union groups. They differed only in the time of appearance of phases. The non-union group demonstrated no recognizable sequential pattern. In this experimental model, serial bone scanning the quantitative data analysis has shown potential for indicating the course of healing in fractures and for serving as a guide to treatment

Differences in Site-Specific Fracture Risk Among Older Women with Discordant Results for Osteoporosis at Hip and Spine: the Study of Osteoporotic Fractures

Science.gov (United States)

Fink, Howard A.; Harrison, Stephanie L.; Taylor, Brent C.; Cummings, Steven R.; Schousboe, John T.; Kuskowski, Michael A.; Stone, Katie L.; Ensrud, Kristine E.

2009-01-01

To examine the fracture pattern in older women whose bone mineral density (BMD) T-score criteria for osteoporosis at hip and spine disagree, hip and spine BMD were measured in Study of Osteoporotic Fractures participants using dual energy x-ray absorptiometry (DXA). Hip osteoporosis was defined as T-score ≤-2.5 at femoral neck or total hip, and spine osteoporosis as T-score ≤-2.5 at lumbar spine. Incident clinical fractures were self-reported and centrally adjudicated. Incident radiographic spine fractures were defined morphometrically. Compared to women with osteoporosis at neither hip nor spine, those osteoporotic only at hip had a 3.0-fold age and weight-adjusted increased risk for hip fracture (95%CI 2.4-3.6), and smaller increases in risk of nonhip nonspine (HR=1.6), clinical spine (OR=2.2), and radiographic spine fractures (OR=1.5). Women osteoporotic only at spine had a 2.8-fold increased odds of radiographic spine fracture (95%CI 2.1-3.8), and smaller increases in risk of clinical spine (OR=1.4), nonhip nonspine (HR=1.6), and hip fractures (HR=1.2). Discordant BMD results predict different fracture patterns. DXA fracture risk estimation in these patients should be site-specific. Women osteoporotic only at spine would not have been identified from hip BMD measurement alone, and may have a sufficiently high fracture risk to warrant preventive treatment. PMID:18296090

Behavior of rare earth elements in fractured aquifers: an application to geological disposal criteria for radioactive waste

International Nuclear Information System (INIS)

Lee, Seung Gu; Kim, Yong Je; Lee, Kil Yong; Kim, Kun Han

2003-01-01

An understanding of the geochemistry of potential host rocks is very important in the site evaluation for construction of an underground geologic repository for radioactive waste. Because of similar valence and ionic radii and high similarity in electronic structure with trivalent actinides (such as Am 3+ and Cm 3+ ), the rare earth elements (REEs) have been used to predict the behavior of actinide-series elements in solution (Runde et al., 1992). For Am and Cm, which occur only in the trivalent states in most waste-disposal repository environments, the analogy with the REEs is particularly relevant. In order to discuss the behavior of REEs in geological media and to deduce the behavior of actinides in geological environments based on the REE abundance, and to provide an useful tool in deciding an optimum geological condition for radioactive disposal, we estimated the REE abundance from various kinds of fractured rock type. In fractured granitic aquifer, chondrite-normalized REE pattern show Eu positive anomaly due to fracture-filling calcite precipitation. However, in fractured meta-basaltic and volcanic tuffaceous aquifer, REE pattern do not show the change of Eu anomaly due to fracture-filling calcite precipitation. Eu shows very similar properties such as cohesive energy, ionic radii with coordination number compared to Am. Therefore, if we consider the Eu behavior in fractured rocks and the similar physical/chemical properties of Eu and Am, together, our results strongly suggest that Eu is a very useful analogue for predicting the behavior of Am in geological environment

Characterization of ductile fracture properties of quench-hardenable boron steel: Influence of microstructure and processing conditions

International Nuclear Information System (INIS)

Golling, Stefan; Östlund, Rickard; Oldenburg, Mats

2016-01-01

Developments of the hot stamping technology have enabled the production of components with differential microstructure composition and mechanical properties. These can increase the performance of certain crash-relevant automotive structures by combining high intrusion protection and energy absorption. This paper presents a comprehensive experimental investigation on the flow and ductile fracture properties of boron-alloyed steel with a wide range of different microstructure compositions. Three types of dual phase microstructures at three different volume fractions, and one triple phase grade, were generated by thermal treatment. Flow curves extending beyond necking and the equivalent plastic strain to fracture for each grade was determined by tensile testing using full-field measurements. The influence of phase composition and microstructural parameters were further investigated by means of a multi-scale modeling approach based on mean-field homogenization in combination with local fracture criteria. Inter-phase and intra-phase fracture mechanisms were considered by adopting two separate fracture criteria formulated in terms of the local average stress field. The micromechanical model captures with useful accuracy the strong influence of microstructure and processing conditions on the flow and fracture properties, implying promising prospects of mean-field homogenization for the constitutive modeling of hot stamped components.

Characterization of ductile fracture properties of quench-hardenable boron steel: Influence of microstructure and processing conditions

Energy Technology Data Exchange (ETDEWEB)

Golling, Stefan, E-mail: stefan.golling@ltu.se [Luleå University of Technology, SE 971 87 Luleå (Sweden); Östlund, Rickard [Gestamp HardTech, Ektjärnsvägen 5, SE 973 45 Luleå (Sweden); Oldenburg, Mats [Luleå University of Technology, SE 971 87 Luleå (Sweden)

2016-03-21

Developments of the hot stamping technology have enabled the production of components with differential microstructure composition and mechanical properties. These can increase the performance of certain crash-relevant automotive structures by combining high intrusion protection and energy absorption. This paper presents a comprehensive experimental investigation on the flow and ductile fracture properties of boron-alloyed steel with a wide range of different microstructure compositions. Three types of dual phase microstructures at three different volume fractions, and one triple phase grade, were generated by thermal treatment. Flow curves extending beyond necking and the equivalent plastic strain to fracture for each grade was determined by tensile testing using full-field measurements. The influence of phase composition and microstructural parameters were further investigated by means of a multi-scale modeling approach based on mean-field homogenization in combination with local fracture criteria. Inter-phase and intra-phase fracture mechanisms were considered by adopting two separate fracture criteria formulated in terms of the local average stress field. The micromechanical model captures with useful accuracy the strong influence of microstructure and processing conditions on the flow and fracture properties, implying promising prospects of mean-field homogenization for the constitutive modeling of hot stamped components.

A case of incomplete atypical femoral fracture with histomorphometrical evidence of osteomalacia.

Science.gov (United States)

Tsuchie, Hiroyuki; Miyakoshi, Naohisa; Nishi, Tomio; Abe, Hidekazu; Segawa, Toyohito; Shimada, Yoichi

2015-01-01

Roughly half of the femoral fracture patients diagnosed with AFF according to the criteria suggested by a task force of the American Society for Bone and Mineral Research (ASBMR) have not undergone bisphosphonate (BP) therapy. One suspected cause of such fractures is severe bone loss due to osteomalacia, but the pathogenesis remains unknown. We report a case of an 84-year-old woman with AFF not treated by BP therapy, in whom underlying osteomalacia was histologically diagnosed. The involvement of femoral curvature and spino-pelvic malaligment in the fracture in the present case was considered.

Prediction of postoperative morbidity, mortality and rehabilitation in hip fracture patients: the cumulated ambulation score

DEFF Research Database (Denmark)

Foss, Nicolai Bang; Kristensen, Morten Tange; Kehlet, Henrik

2006-01-01

fracture patients with an independent walking function admitted from their own home. Rehabilitation followed a well-defined multimodal rehabilitation regimen and discharge criteria. MAIN OUTCOME MEASURE: Admission tests with a new mobility score to assess prefracture functional mobility and a short mental......OBJECTIVE: To validate the cumulated ambulation score as an early postoperative predictor of short-term outcome in hip fracture patients. DESIGN: Prospective, descriptive study. SETTING: An orthopaedic hip fracture unit in a university hospital. PATIENTS: Four hundred and twenty-six consecutive hip...... of short-term postoperative outcome after hip fracture surgery....

Intertrochanteric fractures in elderly high risk patients treated with Ender nails and compression screw

Directory of Open Access Journals (Sweden)

Gangadharan Sidhartha

2010-01-01

Full Text Available Background: Ender and Simon Weidner popularized the concept of closed condylocephlic nailing for intertrochanteric fractures in 1970. The clinical experience of authors revealed that Ender nailing alone cannot provide secure fixation in elderly patients with osteoporosis. Hence we conducted a study to evaluate the efficacy of a combined fixation procedure using Ender nails and a cannulated compression screw for intertrochanteric fractures. Materials and Methods: 76 patients with intertrochanteric fractures were treated using intramedullary Ender nails and cannulated compression screw from January 2004 to December 2007. The mean age of the patients was 80 years (range 70-105 years.Using the Evan′s system of classification 49 were stable and 27 unstable fractures. Inclusion criteria was high risk elderly patients (age > 70 years with intertrochanteric fracture. The exclusion criteria included patients with pressure sores over the trochanteric region. Many patients had pre-existing co-morbidities like diabetes mellitus, hypertension, COPD, ischemic heart disease, CVA and coronary artery bypass surgery. The two Ender nails of 4.5mm each were passed across the fracture site into the proximal neck. This was reinforced with a 6.5 mm cannulated compression screw passed from the sub trochanteric region, across the fracture into the head. Results: The mean follow-up was 14 months (range 9-19 months Average time to fracture union was 10 weeks (range 6-16 weeks. The mean knee ROM was 130o (± 5o. There was no case of nail penetration into hip joint. In five cases with advanced osteoporosis there was minimal migration of Ender nails distally. Conclusions: The Ender nailing combined with compression screw fixation in cases of intertrochanteric fractures in high risk elderly patients could achieve reliable fracture stability with minimal complications.

Dynamic fracture toughness data for CASTOR {sup registered} casks

Energy Technology Data Exchange (ETDEWEB)

Winkler, H.P. [GNS Gesellschaft fuer Nuklear-Service mbH/GNB, Essen (Germany); Trubitz, P.; Pusch, G. [Technische Univ. Bergakademie Freiberg, Freiberg (Germany); Warnke, E.P. [Siempelkamp GmbH and Co. KG, Krefeld (Germany); Beute, K. [Gontermann-Peipers GmbH, Siegen (Germany); Novotny, V. [SKODA, HUTE, Plzen (Czech Republic)

2004-07-01

For the use of cast iron spherical graphite for heavy-sectioned casks for transportation and storage of radiactive materials a complete failure assessment including fracture mechanical analysis is necessary. The casks require an elaborate fracture mechanics design based on fracture mechanics evaluation. The extension of the existing code with respect to dynamic loading takes account new developments to extend the field of applications. It also includes new criteria to design these casks against operating and accident loadings. A fundamental requirement for the realisation of this standard and the calculation of admissible crack lengths of stresses under dynamic loads is the availability of fracture mechanical data. The paper presents-as a part of a large test-program-first results of dynamic fracture-toughness-investigations depending on structure and temperature. The test-program will incorporate investigations on more then 2500 specimens. The investigations that will be done include static and dynamic fracture mechanics tests, dynamic tensile and pressure-tests on different formed specimens. The temperatures and other test conditions follows the IAEA-regulations and the real service conditions. The test-program will be realised in partnership with different institutes.

Subtrochanteric stress fractures in patients on oral bisphosphonate therapy: an emerging problem.

LENUS (Irish Health Repository)

Murphy, Colin G

2012-01-31

The emergence of a new variant of subtrochanteric stress fractures of the femur, affecting patients on oral bisphosphonate therapy, has only recently been described. This fracture is often preceded by pain and distinctive radiographic changes (lateral cortical thickening), and associated with a characteristic fracture pattern (transverse fracture line and medial cortical spike). A retrospective review (2007-2009) was carried out for patients who were taking oral bisphosphonates and who sustained a subtrochanteric fracture after a low velocity injury. Eleven fractures were found in 10 patients matching the inclusion criteria outlined. All were females, and taking bisphosphonates for a mean of 43 years. Five of the 10 patients mentioned prodromal symptoms, for an average of 9.4 months before the fracture. Although all fractures were deemed low velocity, 5 of 11 were even atraumatic. Two patients had previously sustained contralateral subtrochanteric fractures. Plain radiographs of two patients showed lateral cortical thickening on the contralateral unfractured femur; the bisphosphonate therapy was stopped and close surveillance was started. Patients taking oral bisphosphonates may be at risk of a new variant of stress fracture of the proximal femur. Awareness of the symptoms is the key to ensure that appropriate investigations are undertaken.

[Medial versus lateral plating in distal tibial fractures: a prospective study of 40 fractures].

Science.gov (United States)

Encinas-Ullán, C A; Fernandez-Fernandez, R; Rubio-Suárez, J C; Gil-Garay, E

2013-01-01

Tibial plafond fractures are one of the most challenging injuries in orthopaedic surgery. Their results could be improved by following the new guidelines for the management, and modern plating techniques. The results and complication rate between anteromedial and anterolateral approach for open reduction and internal fixation of these fractures were compared. A study was conducted on 40 patients treated by open reduction an internal fixation between 2007 and 2008. The surgical approach was selected by the surgeon in charge, depending on fracture pattern and skin situation. Patients were evaluated clinically and radiographically by an independent orthopaedic surgeon, not involved in the surgical procedure, using clinical (American Orthopaedic Foot and Ankle Society score) and radiological criteria at a minimum of two years. The appearance of complications after both approaches was recorded. Forty patients were included. The mean age was 53 years, with 24 males and 16 females. Seventeen of the injuries were of high energy, and there were 8 open fractures (3 of type i, 4 type ii and one type iii), and 12 of the closed injuries were grade ii or iii in the Tscherne classification. Six patients (15%) had associated injuries. At final follow-up there were 33 (82%) excellent or good results. No statistical differences were found between either surgical approach regarding time to bone union, rate of delayed union and infection rate. Three plates of the anteromedial group and none of the anterolateral group needed to be removed. Open reduction and internal fixation of distal tibia fractures produced reliable results, with no statistical differences found between anteromedial and anterolateral surgical approaches. Clinical and radiological results and complication rate were mainly related to the fracture type. Copyright © 2012 SECOT. Published by Elsevier Espana. All rights reserved.

Pressure vessel inspection criteria based on fitness-for-purpose assessment

International Nuclear Information System (INIS)

Grover, J.L.; Cipolla, R.C.

1985-01-01

The paper on pressure vessel inspection investigates the methodology required to establish an inspection strategy consistent with fracture mechanics analysis, i.e. to define allowable flaw sizes based on location within the vessel. The methodology is demonstrated using a sample problem for a typical pressurised water reactor pressure vessel, and shows the impact of certain assumptions on the inspection strategy. The results indicate that the flaw size varies with the shape of the assumed residual stress field and the through-thickness location. Also in general, the fracture mechanics evaluation allows flaws much larger than are allowed by the inspection acceptance criteria. (UK)

Demonstration and Validation of a Fractured Rock Passive Flux Meter

Science.gov (United States)

2015-04-01

attenuation, and enhanced biodegradation as competitive remediation solutions to chlorinated ethene-contaminated fractured rock. The criteria and...located outside, then some form of weatherproofing for the gauges will be necessary. As a temporary measure, heavy-duty polyethylene bags , secured

The outcome of conservative treatment of adult distal radius fractures compared with the other wrist: radiological and functional evaluation

Directory of Open Access Journals (Sweden)

Mustafa Uslu

2014-09-01

Full Text Available Objective: This study was designed to evaluate anatomical and functional results of closed reduction-long arm cast treatment for distal radius fractures and compared other healthy wrist in the adults. Methods: 77 patients with distal radius fracture were treated conservatively between January 2010 and December 2010. The fractures were classified according to AO and Frykman classification system and investigated prospectively. The radiological and anatomical results were assessed by the Stewart score criteria. The functional results were assessed by Quick-Disability of Arm, Shoulder and Hand questionnaire (Q-DASH and the Stewart II score criteria. The mean follow-up of patients was 12 months. Results: The forty patients had right wrist fractured, 37 patients had left wrist fractured. According to Frykman classification 46 patients were type I-II fractured, according to AO classification 59 patients were type 23,A2,1 and 23,A2,2 fractured. According to Stewart the radiological and anatomical, the result were excellent in 57, good in 17, fair in 3. According to Stewart II functional criteria, the results were assessed excellent in 57, good in 8, fair in 12 The mean Q-DASH score was 6,37. The overall complication rate was 12.98%. Mild Carpal tunnel syndrome was observed in the two patients, ulna styloid nonunion in the four patients, pain of distal radioulnar joint in the one patient, mild carpal tunnel syndrome and tenderness of distal radioulnar joint in the three patients. Conclusion: Closed reduction and cast immobilization is still an effective and inexpensive treatment method in distal radial fractures. J Clin Exp Invest 2014; 5 (3: 403-409

Comparisons of non-destructive examination standards in the framework of fracture mechanics approach

International Nuclear Information System (INIS)

Reale, S.; Corvi, A.

1993-01-01

One of the aims of the various Engineering Standards related to Non-destructive Examination (NDE) is to identify and limit some characteristics of defects in a structure, since the degree of damage of a structure can be associated with these defect characteristics. One way that the damage level can be evaluated is by means of Fracture Mechanics. The objective of the present paper is to compare and identify the differences in the flaw acceptance criteria of national NDE Standards so as to suggest some guidelines for a future common European Standard. This paper examines the Standards adopted in France (RCC-MR), Germany (DIN), Italy (ASME) and the UK (BSI). It concentrates on both ultrasonic and radiographic inspection methods. The flaw acceptance criteria in these standards relating to non-destructive tests performed on a component during manufacturing are compared and evaluated by the Fracture Mechanics CEGB R6 procedure. General guidelines and results supporting the significance of the Fracture Mechanics approach are given. (Author)

Fracture mechanics analyses of ceramic/veneer interface under mixed-mode loading.

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Wang, Gaoqi; Zhang, Song; Bian, Cuirong; Kong, Hui

2014-11-01

Few studies have focused on the interface fracture performance of zirconia/veneer bilayered structure, which plays an important role in dental all-ceramic restorations. The purpose of this study was to evaluate the fracture mechanics performance of zirconia/veneer interface in a wide range of mode-mixities (at phase angles ranging from 0° to 90°), and to examine the effect of mechanical properties of the materials and the interface on the fracture initiation and crack path of an interfacial crack. A modified sandwich test configuration with an oblique interfacial crack was proposed and calibrated to choose the appropriate geometry dimensions by means of finite element analysis. The specimens with different interface inclination angles were tested to failure under three-point bending configuration. Interface fracture parameters were obtained with finite element analyses. Based on the interfacial fracture mechanics, three fracture criteria for crack kinking were used to predict crack initiation and propagation. In addition, the effects of residual stresses due to coefficient of thermal expansion mismatch between zirconia and veneer on the crack behavior were evaluated. The crack initiation and propagation were well predicted by the three fracture criteria. For specimens at phase angle of 0, the cracks propagated in the interface; whereas for all the other specimens the cracks kinked into the veneer. Compressive residual stresses in the veneer can improve the toughness of the interface structure. The results suggest that, in zirconia/veneer bilayered structure the veneer is weaker than the interface, which can be used to explain the clinical phenomenon that veneer chipping rate is larger than interface delamination rate. Consequently, a veneer material with larger fracture toughness is needed to decrease the failure rate of all-ceramic restorations. And the coefficient of thermal expansion mismatch of the substrates can be larger to produce larger compressive

Does Alendronate reduce the risk of fracture in men? A meta-analysis incorporating prior knowledge of anti-fracture efficacy in women

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Papaioannou Alexandra

2005-07-01

Full Text Available Abstract Background Alendronate has been found to reduce the risk of fractures in postmenopausal women as demonstrated in multiple randomized controlled trials enrolling thousands of women. Yet there is a paucity of such randomized controlled trials in osteoporotic men. Our objective was to systematically review the anti-fracture efficacy of alendronate in men with low bone mass or with a history of prevalent fracture(s and incorporate prior knowledge of alendronate efficacy in women in the analysis. Methods We examined randomized controlled trials in men comparing the anti-fracture efficacy of alendronate to placebo or calcium or vitamin D, or any combination of these. Studies of men with secondary causes of osteoporosis other than hypogonadism were excluded. We searched the following electronic databases (without language restrictions for potentially relevant citations: Medline, Medline in Process (1966-May 24/2004, and Embase (1996–2004. We also contacted the manufacturer of the drug in search of other relevant trials. Two reviewers independently identified two trials (including 375 men, which met all inclusion criteria. Data were abstracted by one reviewer and checked by another. Results of the male trials were pooled using Bayesian random effects models, incorporating prior information of anti-fracture efficacy from meta-analyses of women. Results The odds ratios of incident fractures in men (with 95% credibility intervals with alendronate (10 mg daily were: vertebral fractures, 0.44 (0.23, 0.83 and non-vertebral fractures, 0.60 (0.29, 1.44. Conclusion In conclusion, alendronate decreases the risk of vertebral fractures in men at risk. There is currently insufficient evidence of a statistically significant reduction of non-vertebral fractures, but the paucity of trials in men limit the statistical power to detect such an effect.

Adolescent Volar Barton Fracture with Open Physis treated with Volar Plating using Buttressing Principle

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Shah H

2015-07-01

Full Text Available Objective: The objective of the study was to assess the outcome of Salter- Harris type III distal radius fracture fixed using the principle of buttressing and avoiding screw insertion through the physis. Materials and Method: Eight school going children in the age group of 11-16 years with volar Barton fractures were treated with a volar plate using the buttress principle without inserting screws in the distal fragment. Patients were evaluated over a period of 18 months. Clinical evaluation was done using the Green O’Brien criteria and radiological evaluation using the Sarmiento criteria. Results: The average union time was two months. All the patients had good to excellent functional outcome with full extension and flexion. Conclusion: Buttress plating of volar Barton fractures in the adolescent age group is an excellent technique to achieve satisfactory outcome without violation of the physis.

Effect of combined loading due to bending and internal pressure on pipe flaw evaluation criteria

International Nuclear Information System (INIS)

Miura, Naoki; Sakai, Shinsuke

2006-01-01

Considering a rational maintenance rule of Light Water Reactor piping, reliable flaw evaluation criteria are essential to determine how a detected flaw is detrimental to continuous plant operation. Ductile fracture is one of the dominant failure modes to be considered for carbon steel piping, and can be analyzed by the elastic-plastic fracture mechanics. Some analytical efforts have been provided as flaw evaluation criteria using load correction factors such like the Z-factors in the JSME codes on fitness-for-service for nuclear power plants or the ASME boiler and pressure vessel code section XI. The present correction factors were conventionally determined taken conservatism and simplicity into account, however, the effect of internal pressure which would be an important factor under an actual plant condition was not adequately considered. Recently, a J-estimation scheme, 'LBB. ENGC' for ductile fracture analysis of circumferentially through-wall-cracked pipes subjected combined loading was newly developed to have a better prediction with more realistic manner. This method is explicitly incorporated the contribution of both bending and tension due to internal pressure by means of the scheme compatible with an arbitrary combined loading history. In this paper, the effect of internal pressure on the flaw evaluation criteria was investigated using the new J-estimation scheme. A correction factor based on the new J-estimation scheme was compared with the present correction factors, and the predictability of the current flaw evaluation criteria was quantitatively evaluated in consideration of internal pressure. (author)

Flexible intramedullary nailing for femoral diaphyseal fractures in children

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Rojan Tamrakar

2017-12-01

Full Text Available Background & Objectives: Although various treatment options are available for the treatment of femoral diaphyesal fractures in children, the titanium flexible nailing has gained popularity because it is safe, easy procedure with rapid recovery and high success rate. The aim of this study was to evaluate the outcome of titanium elastic nails in treating paediatric femoral diaphyesal fractures at Patan Hospital.Materials & Methods: There were 35 cases which were all fixed with titanium flexible intramedullary nail under image intensifier at the Patan hospital from January 2013 and December 2015. Patients were evaluated in follow-ups to observe the alignment of fracture, infection, delayed union, nonunion, limb length discrepancy, implant failure, range of movement of hip and knee joints, and time to unite the fracture. The final results were evaluated using criteria of titanium elastic nail (TEN outcome score described by Flynn et al.Results: The mean age of the patients was 8.51 years. Among 35 patients (22 boys and 13 girls, there were 19 mid-shaft fractures, nine proximal third fractures and seven distal third fractures. Fracture patterns were transverse (22, oblique (10, spiral (2, and comminuted (2. The mean time for fracture union was 8.17 weeks radiologically whereas 9.83 weeks clinically. According to TEN outcome score, excellent and good results were in 28 cases (80% and seven cases (20% respectively.Conclusion: Flexible titanium nailing is a safe and satisfactory treatment for diaphyseal femoral fractures in children, because it provides rapid recovery, short rehabilitation and immobilization as well as very high union rate with few complications.

A new insight into ductile fracture of ultrafine-grained Al-Mg alloys.

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Yu, Hailiang; Tieu, A Kiet; Lu, Cheng; Liu, Xiong; Liu, Mao; Godbole, Ajit; Kong, Charlie; Qin, Qinghua

2015-04-08

It is well known that when coarse-grained metals undergo severe plastic deformation to be transformed into nano-grained metals, their ductility is reduced. However, there are no ductile fracture criteria developed based on grain refinement. In this paper, we propose a new relationship between ductile fracture and grain refinement during deformation, considering factors besides void nucleation and growth. Ultrafine-grained Al-Mg alloy sheets were fabricated using different rolling techniques at room and cryogenic temperatures. It is proposed for the first time that features of the microstructure near the fracture surface can be used to explain the ductile fracture post necking directly. We found that as grains are refined to a nano size which approaches the theoretical minimum achievable value, the material becomes brittle at the shear band zone. This may explain the tendency for ductile fracture in metals under plastic deformation.

Posterior trochanteric osteotomy in acetabular fractures for 32 cases.

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Niu, Yunfei; An, Xiaofei; Xu, Shuogui; Wu, Dajiang; Zhang, Chuncai; Li, Ming

2014-11-01

The aim of this study is to explore the method and clinical outcome of posterior trochanteric osteotomy in acetabular fractures. From January 2000 to January 2008, 32 cases of acetabular fractures involving the dome of acetabulum underwent posterior trochanteric osteotomy for a better exposure and internal fixation with acetabular tridimensional memory fixation system. 28 cases (16 men and 12 women, mean age 39.9 years, range 16-73 years) were followed up with an average of 48.9 months (range of 19-95 months) and four were lost during follow up. Of 28 cases, 19 were fresh fractures and 9 were old fractures. The reduction was evaluated with Matta criteria. Clinical evaluation was based on modified Merle d'Aubigne and Postel scoring. Motor strength of the abductors was evaluated according to the Medical Research Council grading system. Ectopic ossification was classified according to Brooker criteria. Anatomical reduction was achieved in 17 cases and satisfied reduction in 10 patients. Poor reduction happened in an old fracture. All acetabular fractures got a direct bone union and no displacement and deep infection occurred. All osteotomies healed within 3.5 months without any nonunion, proximal migration of the greater trochanter, loosing or broken of instrumentation, and deep infection. Two superficial infections were healed with a regular dressing. Two patients underwent removal of implants from greater trochanter because of irritation. The strength of the abductors was of Grade 3/5 in two patients, Grade 4/5 in five patients, and normal in the rest. Clinical scoring was excellent to good in 84 %. Ectopic ossification occurred in five patients, grade 1 in two patients, grade 2 in two, and grade 3 in one. But function of hip joint was not seriously affected. Posterior trochanteric osteotomy can provide an adequate exposure of the dome of acetabulum without the associated complications like nonunion, proximal replacement, and weak of the abductors which often occur

Mechanical transport in two-dimensional networks of fractures

International Nuclear Information System (INIS)

Endo, H.K.

1984-04-01

The objectives of this research are to evaluate directional mechanical transport parameters for anisotropic fracture systems, and to determine if fracture systems behave like equivalent porous media. The tracer experiments used to measure directional tortuosity, longitudinal geometric dispersivity, and hydraulic effective porosity are conducted with a uniform flow field and measurements are made from the fluid flowing within a test section where linear length of travel is constant. Since fluid flow and mechanical transport are coupled processes, the directional variations of specific discharge and hydraulic effective porosity are measured in regions with constant hydraulic gradients to evaluate porous medium equivalence for the two processes, respectively. If the fracture region behaves like an equivalent porous medium, the system has the following stable properties: (1) specific discharge is uniform in any direction and can be predicted from a permeability tensor; and (2) hydraulic effective porosity is directionally stable. Fracture systems with two parallel sets of continuous fractures satisfy criterion 1. However, in these systems hydraulic effective porosity is directionally dependent, and thus, criterion 2 is violated. Thus, for some fracture systems, fluid flow can be predicted using porous media assumptions, but it may not be possible to predict transport using porous media assumptions. Two discontinuous fracture systems were studied which satisfied both criteria. Hydraulic effective porosity for both systems has a value between rock effective porosity and total porosity. A length-density analysis (LDS) of Canadian fracture data shows that porous media equivalence for fluid flow and transport is likely when systems have narrow aperture distributions. 54 references, 90 figures, 7 tables

FRACTURE OF THE CENTRAL TARSAL BONE IN NONRACEHORSES: FOUR CASES.

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Knuchell, Jeannie A; Spriet, Mathieu; Galuppo, Larry D; Katzman, Scott A

2016-07-01

Fractures of the central tarsal bone are a rarely recognized cause of acute severe hind limb lameness in nonracehorses. Diagnosis of these fractures can be challenging and little is known about their configuration or outcome. The objectives of this retrospective case series study were to describe the clinical features, imaging findings, and outcomes of fractures of the central tarsal bone in a sample of nonracehorses. Medical records from 2001 to 2014 were searched for cases of central tarsal bone fractures in nonracehorses. All available imaging findings including radiography, ultrasound, computed tomography (CT), and/or nuclear scintigraphy were reviewed. History, clinical presentation, and outcome were collected from the records. Four horses met the inclusion criteria. All had a similar configuration as a simple nondisplaced slab fracture in a dorsomedial to plantarolateral orientation. Initial radiographs failed to reveal the fracture in three of four cases. When additional plantarolateral-dorsomedial oblique radiographic views were obtained, the fracture could be identified in all cases. Fractures of the central tarsal bone seemed to occur in a consistent dorsomedial to plantarolateral orientation in this sample of nonracehorses, which is different from the configuration previously reported in racehorses. While CT can be used for detection and assessment of these fractures, authors propose that radiography can also identify these fractures with the appropriate view. Authors recommend the use of several plantarolateral to dorsomedial radiographic projections at varying degrees of obliquity for horses with a suspected central tarsal bone fracture. © 2016 American College of Veterinary Radiology.

Effect of Random Natural Fractures on Hydraulic Fracture Propagation Geometry in Fractured Carbonate Rocks

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Liu, Zhiyuan; Wang, Shijie; Zhao, Haiyang; Wang, Lei; Li, Wei; Geng, Yudi; Tao, Shan; Zhang, Guangqing; Chen, Mian

2018-02-01

Natural fractures have a significant influence on the propagation geometry of hydraulic fractures in fractured reservoirs. True triaxial volumetric fracturing experiments, in which random natural fractures are created by placing cement blocks of different dimensions in a cuboid mold and filling the mold with additional cement to create the final test specimen, were used to study the factors that influence the hydraulic fracture propagation geometry. These factors include the presence of natural fractures around the wellbore, the dimension and volumetric density of random natural fractures and the horizontal differential stress. The results show that volumetric fractures preferentially formed when natural fractures occurred around the wellbore, the natural fractures are medium to long and have a volumetric density of 6-9%, and the stress difference is less than 11 MPa. The volumetric fracture geometries are mainly major multi-branch fractures with fracture networks or major multi-branch fractures (2-4 fractures). The angles between the major fractures and the maximum horizontal in situ stress are 30°-45°, and fracture networks are located at the intersections of major multi-branch fractures. Short natural fractures rarely led to the formation of fracture networks. Thus, the interaction between hydraulic fractures and short natural fractures has little engineering significance. The conclusions are important for field applications and for gaining a deeper understanding of the formation process of volumetric fractures.

Utility of Postoperative Antibiotics After Percutaneous Pinning of Pediatric Supracondylar Humerus Fractures.

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Schroeder, Nicholas O; Seeley, Mark A; Hariharan, Arun; Farley, Frances A; Caird, Michelle S; Li, Ying

2017-09-01

Pediatric supracondylar humerus fractures are common injuries that are often treated surgically with closed reduction and percutaneous pinning. Although surgical-site infections are rare, postoperative antibiotics are frequently administered without evidence or guidelines for their use. With the increasing prevalence of antibiotic-resistant organisms and heightened focus on health care costs, appropriate and evidence-based use of antibiotics is needed. We hypothesized that postoperative antibiotic administration would not decrease the rate of surgical-site infection. A billing query identified 951 patients with operatively treated supracondylar humerus fractures at our institution over a 15-year period. Records were reviewed for demographic data, perioperative antibiotic use, and the presence of surgical-site infection. Exclusion criteria were open fractures, open reduction, pathologic fractures, metabolic bone disease, the presence of other injuries that required operative treatment, and follow-up <2 weeks after pin removal. χ and Fisher exact test were used to compare antibiotic use to the incidence of surgical-site infection. Six hundred eighteen patients met our inclusion criteria. Two hundred thirty-eight patients (38.5%) received postoperative antibiotics. Eleven surgical-site infections were identified for an overall rate of 1.8%. The use of postoperative antibiotics was not associated with a lower rate of surgical-site infection (P=0.883). Patients with a type III fracture (P<0.001), diminished preoperative vascular (P=0.001) and neurological status (P=0.019), and postoperative hospital admission (P<0.001) were significantly more likely to receive postoperative antibiotics. Administration of postoperative antibiotics after closed reduction and percutaneous pinning of pediatric supracondylar humerus fractures does not decrease the rate of surgical-site infection. Level III-therapeutic.

Operative treatment of lateral humeral condyle fractures in children.

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Wirmer, Johannes; Kruppa, Christian; Fitze, Guido

2012-08-01

The operative treatment of lateral humeral condyle fractures in children remains controversial. The result of incorrectly treated fractures may lead to complications such as pseudoarthrosis and severe deformity, with considerable functional and cosmetic restrictions. The aim of this study was to determine whether operative treatment of lateral humeral condyle fractures in children using Screw-wires (Orthofix GmbH, Ottobrunn, Germany) has any advantage over treatment with Kirschner wires ("K-wires") (aap-Implantate AG, Berlin, Germany). These results were then compared with operative treatment using lag-screw osteosynthesis. We treated surgically 76 cases of fracture of the lateral humeral condyle in children at the Department of Pediatric Surgery in Dresden between 1989 to 2002 and 2004 to 2008, from which 42 were available for follow-up examination. Within this group, there were seven children that were followed-up twice (in 1996 to 2002). Of these, 21 patients were treated with Screw-wires, and another 21 had K-wires inserted. The results were evaluated according to the Dhillon criteria. Only seven patients (17%) had a fair result in the overall grading according to the Dhillon criteria, four after K-wire and three after Screw-wire osteosyntheses. The remaining patients scored good to excellent results. There were no pseudoarthroses. Six patients (14%) had a varisation in the carrying angle between 10 and 16 degrees (three each procedure), and 15 patients (36%) had no difference in the carrying angle at all. Of these 15 patients, 10 were treated with Screw-wire osteosynthesis. Only one patient (2.4%) had a deficit of more than 10 degrees in elbow joint flexion, while only two (4.8%, one each procedure) had a deficit of more than 10 degrees in elbow joint extension, compared with the uninjured arm. Our results demonstrate that the employment of Screw-wire osteosynthesis is superior to the use of K-wires concerning the carrying angle while scoring alike on the

Classifications of Acute Scaphoid Fractures: A Systematic Literature Review.

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Ten Berg, Paul W; Drijkoningen, Tessa; Strackee, Simon D; Buijze, Geert A

2016-05-01

Background In the lack of consensus, surgeon-based preference determines how acute scaphoid fractures are classified. There is a great variety of classification systems with considerable controversies. Purposes The purpose of this study was to provide an overview of the different classification systems, clarifying their subgroups and analyzing their popularity by comparing citation indexes. The intention was to improve data comparison between studies using heterogeneous fracture descriptions. Methods We performed a systematic review of the literature based on a search of medical literature from 1950 to 2015, and a manual search using the reference lists in relevant book chapters. Only original descriptions of classifications of acute scaphoid fractures in adults were included. Popularity was based on citation index as reported in the databases of Web of Science (WoS) and Google Scholar. Articles that were cited <10 times in WoS were excluded. Results Our literature search resulted in 308 potentially eligible descriptive reports of which 12 reports met the inclusion criteria. We distinguished 13 different (sub) classification systems based on (1) fracture location, (2) fracture plane orientation, and (3) fracture stability/displacement. Based on citations numbers, the Herbert classification was most popular, followed by the Russe and Mayo classifications. All classification systems were based on plain radiography. Conclusions Most classification systems were based on fracture location, displacement, or stability. Based on the controversy and limited reliability of current classification systems, suggested research areas for an updated classification include three-dimensional fracture pattern etiology and fracture fragment mobility assessed by dynamic imaging.

Prevalence of Abuse Among Young Children with Rib Fractures: A Systematic Review

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Paine, Christine Weirich; Fakeye, Oludolapo; Christian, Cindy W.; Wood, Joanne N.

2016-01-01

Objectives We aimed to estimate the prevalence of abuse in young children presenting with rib fractures and to identify demographic, injury, and presentation-related characteristics that affect the probability that rib fractures are secondary to abuse. Methods We searched PubMed/MEDLINE and CINAHL databases for articles published in English between January 1, 1990 and June 30, 2014 on rib fracture etiology in children ≤ 5 years old. Two reviewers independently extracted predefined data elements and assigned quality ratings to included studies. Study-specific abuse prevalences and the sensitivities, specificities, and positive and negative likelihood ratios of patients’ demographic and clinical characteristics for abuse were calculated with 95% confidence intervals. Results Data for 1,396 children ≤ 48 months old with rib fractures were abstracted from 10 articles. Among infants Rib fracture location was not associated with likelihood of abuse. The retrospective design of the included studies and variations in ascertainment of cases, inclusion/exclusion criteria, and child abuse assessments prevented further meta-analysis. Conclusions Abuse is the most common cause of rib fractures in infants rib fractures and characteristics associated with abusive rib fractures. PMID:27749806

3D Simulation of Multiple Simultaneous Hydraulic Fractures with Different Initial Lengths in Rock

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Tang, X.; Rayudu, N. M.; Singh, G.

2017-12-01

Hydraulic fracturing is widely used technique for extracting shale gas. During this process, fractures with various initial lengths are induced in rock mass with hydraulic pressure. Understanding the mechanism of propagation and interaction between these induced hydraulic cracks is critical for optimizing the fracking process. In this work, numerical results are presented for investigating the effect of in-situ parameters and fluid properties on growth and interaction of multi simultaneous hydraulic fractures. A fully coupled 3D fracture simulator, TOUGH- GFEM is used for simulating the effect of different vital parameters, including in-situ stress, initial fracture length, fracture spacing, fluid viscosity and flow rate on induced hydraulic fractures growth. This TOUGH-GFEM simulator is based on 3D finite volume method (FVM) and partition of unity element method (PUM). Displacement correlation method (DCM) is used for calculating multi - mode (Mode I, II, III) stress intensity factors. Maximum principal stress criteria is used for crack propagation. Key words: hydraulic fracturing, TOUGH, partition of unity element method , displacement correlation method, 3D fracturing simulator

Insights on fluid-rock interaction evolution during deformation from fracture network geochemistry at reservoir-scale

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Beaudoin, Nicolas; Koehn, Daniel; Lacombe, Olivier; Bellahsen, Nicolas; Emmanuel, Laurent

2015-04-01

. The lengthscale of the migration and the nature of invading fluids during these connections is different in every studied example, and can be related to the tectonic nature of the fold, along with the burial depth at the time of deformation. Thus, to decipher fluid-fracture relationships provides insights to better reconstruct the mechanisms of deformation at reservoir-scale.

Study of occurrence, demography and pathomorphology of ankle and foot fractures and evaluation of the treatment outcome of calcaneal fractures

International Nuclear Information System (INIS)

Sarfraz, A.H.; Masood, F.

2014-01-01

This study highlights which injury has greatest burden, how frequent are the injuries of foot and ankle areas, which is an extremely neglected specialty in orthopedics and also the importance of proper diagnosis, classification of fractures, appropriate pre-operative planning and timely conservative as well as surgical intervention of ankle and foot fractures that resulted in a satisfactory outcome Despite the fact, foot and ankle is the most important locomotor unit of our lower limb, there have been few studies addressing the problem and treatment outcome of such fractures. Objective: To determine the occurrence, demography and pathomorphology of ankle and foot fractures, also evaluation of treatment outcome of calcaneal fractures. Methodology: This was a longitudinal interventional study which dealt with acute traumatic ankle and foot fracture patients coming to Accident and Emergency Department of MHL, DOST unit 1, with inclusion and exclusion criteria clearly defined. Results: Total 100 patients were included in the study. Mean age of patients was 35.71+-13.60 years. Minimum age of patients was 14 and maximum age of patients was 70 years respectively. Gender distribution of patients shows that 15 patients were female and the remaining 85 patients were male. Male patients were greater in number as compared to female patients ie. M: F, 6:1. Mechanism of the injury showed that there were 48 patients who suffered from RTA , 37 patients had trauma due to fall from height, 6 patients had industrial injuries, 5 patients had Fire Arm Injury, and 2 patients had injuries due to domestic activity, 1 had trauma due to sports activity and 1 had injury due to agricultural work. There were 41 patients with fractures of calcaneum and out of which 5 had bilateral fracture calcaneum. They were classified according to CT based Sanders classification. Out of these 22 patients were of Sanders type III, 12 patients were of Sander type II, 5 patients were of Sander type IV, 2

Femoral neck fractures after removal of hardware in healed trochanteric fractures.

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Barquet, Antonio; Giannoudis, Peter V; Gelink, Andrés

2017-12-01

Hardware removal in healed trochanteric fractures (TF) in the absence of infection or significant mechanical complications is rarely indicated. However, in patients with persistent pain, prominent material and discomfort in the activities of daily living, the implant is eventually removed. Publications of ipsilateral femoral neck fracture after removal of implants from healed trochanteric fractures (FNFARIHTF) just because of pain or discomfort are rare. The purpose of this systematic review of the literature is to report on the eventual risk factors, the mechanisms, the clinical presentation, and frequency, and to pay special emphasis in their prevention. A comprehensive review of the literature was undertaken using the PRISMA guidelines with no language restriction. Case reports of FNFARIHTF and series of TF with cases of FNFARIHTF due to pain or discomfort published between inception of journals to December 2016 were eligible for inclusion. Relevant information was divided in two parts. Part I included the analysis of cases of FNFARIHTF, with the objective of establishing the eventual risk factors, mechanisms and pathoanatomy, clinical presentation and diagnosis, treatment and prevention. Part II analyzed series of TF which included cases of FNFARIHTF for assessing the incidence of femoral neck fractures in this condition. Overall 24 publications with 45 cases of FNFARIHTF met the inclusion criteria. We found that the only prevalent factors for FNFARIHTF were: 1) preexisisting systemic osteoporosis, as most patients were older and elder females, with lower bone mineral density and bone mass; 2) local osteoporosis as a result of preloading by the fixation device in the femoral neck, leading to stress protection, reducing the strain at the neck, and increasing bone loss and weakness; and 3) the removal of hardware from the femoral neck, with reduction of the failure strength of the neck. The femoral neck fractures were spontaneous, i.e. not related to trauma or

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

International Nuclear Information System (INIS)

Nachtrab, O.; Cassar-Pullicino, V.N.; Lalam, R.; Tins, B.; Tyrrell, P.N.M.; Singh, J.

2012-01-01

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.

OUTCOME OF GARTLAND TYPE – II SUPRACONDYLAR FRACTURES OF HUMERUS TREATED BY CONSERVATIVE METHOD

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Dinesh Mitra

2015-08-01

Full Text Available BACKGROUND: The current literatures recommend operative method (closed reduction and pinning for type II supracondylar fractures of humerus. But some surgeons still prefer conservative method for type II supracondylar fractures of humerus. We pr esent results of 14 cases of type II supracondylar fractures treated with CR and AE POP immobilization . The purpose of this study is to evaluate the outcome of conservative treatment in management of type II supracondylar fracture of humerus. MATERIALS AND METHODS: Fourteen children treated by conservative methods (CR & AE POP between January 2013 and December 2014 is included in this study. The mean age group is 6.8 years (3 years - 11 years. The patient follow up is done for a minimum of 10 - 12 weeks. Treatment outcome is based on final clinical and radiological assessments and grading of results was done using Flynn’s criteria. RESULTS: Gartland type II fracture gives 82% excellent results and 28 % good results as per Flynn’s criteria. Of the 14 patien ts only two cases required re manipulation. Surgical intervention was not needed for any of the patients. No patients in this study developed compartment syndrome / cubitus varus deformity. CONCLUSION: Satisfactory results can be obtained with conservative treatment (closed reduction and above elbow POP if proper selection of the patient and careful clinical and radiological follow up is done

Paratrooper's ankle fracture: posterior malleolar fracture.

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Young, Ki Won; Kim, Jin-su; Cho, Jae Ho; Kim, Hyung Seuk; Cho, Hun Ki; Lee, Kyung Tai

2015-03-01

We assessed the frequency and types of ankle fractures that frequently occur during parachute landings of special operation unit personnel and analyzed the causes. Fifty-six members of the special force brigade of the military who had sustained ankle fractures during parachute landings between January 2005 and April 2010 were retrospectively analyzed. The injury sites and fracture sites were identified and the fracture types were categorized by the Lauge-Hansen and Weber classifications. Follow-up surveys were performed with respect to the American Orthopedic Foot and Ankle Society ankle-hindfoot score, patient satisfaction, and return to preinjury activity. The patients were all males with a mean age of 23.6 years. There were 28 right and 28 left ankle fractures. Twenty-two patients had simple fractures and 34 patients had comminuted fractures. The average number of injury and fractures sites per person was 2.07 (116 injuries including a syndesmosis injury and a deltoid injury) and 1.75 (98 fracture sites), respectively. Twenty-three cases (41.07%) were accompanied by posterior malleolar fractures. Fifty-five patients underwent surgery; of these, 30 had plate internal fixations. Weber type A, B, and C fractures were found in 4, 38, and 14 cases, respectively. Based on the Lauge-Hansen classification, supination-external rotation injuries were found in 20 cases, supination-adduction injuries in 22 cases, pronation-external rotation injuries in 11 cases, tibiofibular fractures in 2 cases, and simple medial malleolar fractures in 2 cases. The mean follow-up period was 23.8 months, and the average follow-up American Orthopedic Foot and Ankle Society ankle-hindfoot score was 85.42. Forty-five patients (80.36%) reported excellent or good satisfaction with the outcome. Posterior malleolar fractures occurred in 41.07% of ankle fractures sustained in parachute landings. Because most of the ankle fractures in parachute injuries were compound fractures, most cases had to

Vitamin E and the Healing of Bone Fracture: The Current State of Evidence

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Boekhtiar Borhanuddin

2012-01-01

Full Text Available Background. The effect of vitamin E on health-related conditions has been extensively researched, with varied results. However, to date, there was no published review of the effect of vitamin E on bone fracture healing. Purpose. This paper systematically audited past studies of the effect of vitamin E on bone fracture healing. Methods. Related articles were identified from Medline, CINAHL, and Scopus databases. Screenings were performed based on the criteria that the study must be an original study that investigated the independent effect of vitamin E on bone fracture healing. Data were extracted using standardised forms, followed by evaluation of quality of reporting using ARRIVE Guidelines, plus recalculation procedure for the effect size and statistical power of the results. Results. Six animal studies fulfilled the selection criteria. The study methods were heterogeneous with mediocre reporting quality and focused on the antioxidant-related mechanism of vitamin E. The metasynthesis showed α-tocopherol may have a significant effect on bone formation during the normal bone remodeling phase of secondary bone healing. Conclusion. In general, the effect of vitamin E on bone fracture healing remained inconclusive due to the small number of heterogeneous and mediocre studies included in this paper.

Effect of combined loading due to bending and internal pressure on pipe flaw evaluation criteria

International Nuclear Information System (INIS)

Miura, Naoki; Sakai, Shinsuke

2008-01-01

Considering a rule for the rationalization of maintenance of Light Water Reactor piping, reliable flaw evaluation criteria are essential for determining how a detected flaw will be detrimental to continuous plant operation. Ductile fracture is one of the dominant failure modes that must be considered for carbon steel piping and can be analyzed by elastic-plastic fracture mechanics. Some analytical efforts have provided various flaw evaluation criteria using load correction factors, such as the Z-factors in the JSME codes on fitness-for-service for nuclear power plants and the section XI of the ASME boiler and pressure vessel code. The present Z-factors were conventionally determined, taking conservativity and simplicity into account; however, the effect of internal pressure, which is an important factor under actual plant conditions, was not adequately considered. Recently, a J-estimation scheme, LBB.ENGC for the ductile fracture analysis of circumferentially through-wall-cracked pipes subjected to combined loading was developed for more accurate prediction under more realistic conditions. This method explicitly incorporates the contributions of both bending and tension due to internal pressure by means of a scheme that is compatible with an arbitrary combined-loading history. In this study, the effect of internal pressure on the flaw evaluation criteria was investigated using the new J-estimation scheme. The Z-factor obtained in this study was compared with the presently used Z-factors, and the predictability of the current flaw evaluation criteria was quantitatively evaluated in consideration of the internal pressure. (author)

Treatment of Middle Third Humeral Shaft Fractures with Anteromedial Plate Osteosynthesis through an Anterolateral Approach.

Science.gov (United States)

Kumar, B S; Soraganvi, P; Satyarup, D

2016-03-01

Background: Treatment of humeral shaft fractures has been a subject of debate for many decades. Even though a large majority of humeral shaft fractures can be treated by non operative methods, few conditions like open fractures, polytrauma, ipsilateral humeral shaft and forearm fractures require surgical intervention. The goal of treatment of humeral shaft fractures is to establish union with an acceptable humeral alignment and to restore the patient to pre-injury level of function. The objective was to assess the incidence of radial nerve palsy, non-union and mean time required for in anteromedial plate osteosynthesis with anterolateral approach and also to measure the functional outcome of this procedure. Method: A prospective study was conducted in the Department of Orthopaedics, PESIMSR, Kuppam, Andhra Pradesh, from August 2012 to August 2015 with a total of 54 patients who were operated with anteromedial plate osteosynthesis were included in the study. Rodriguez- Merchan criteria was used to grade the functional outcome. Results: Of the 54 patients, 28 (58.85%) were in the age group of 30-40 years. The most common fracture pattern identified was A3 type (48.14%).The mean (± SD) duration of surgery for anteromedial humeral plating was 53 ± 5.00 minutes. The time taken for the fracture to unite was less than 16 weeks in the majority or 50 patients (92.59%). Four (7.40%) patients had delayed union. There was no incidence of iatrogenic radial nerve palsy. Rodriguez - Merchan criteria showed that 37(68.51%) of the patients had good and 12 (22.22%) had excellent functional outcome.

Microstructural characterization, petrophysics and upscaling - from porous media to fractural media

Science.gov (United States)

Liu, J.; Liu, K.; Regenauer-Lieb, K.

2017-12-01

We present an integrated study for the characterization of complex geometry, fluid transport features and mechanical deformation at micro-scale and the upscaling of properties using microtomographic data: We show how to integrate microstructural characterization by the volume fraction, specific surface area, connectivity (percolation), shape and orientation of microstructures with identification of individual fractures from a 3D fractural network. In a first step we use stochastic analyses of microstructures to determine the geometric RVE (representative volume element) of samples. We proceed by determining the size of a thermodynamic RVE by computing upper/lower bounds of entropy production through Finite Element (FE) analyses on a series of models with increasing sizes. The minimum size for thermodynamic RVE's is identified on the basis of the convergence criteria of the FE simulations. Petrophysical properties (permeability and mechanical parameters, including plastic strength) are then computed numerically if thermodynamic convergence criteria are fulfilled. Upscaling of properties is performed by means of percolation theory. The percolation threshold is detected by using a shrinking/expanding algorithm on static micro-CT images of rocks. Parameters of the scaling laws can be extracted from quantitative analyses and/or numerical simulations on a series of models with similar structures but different porosities close to the percolation threshold. Different rock samples are analyzed. Characterizing parameters of porous/fractural rocks are obtained. Synthetic derivative models of the microstructure are used to estimate the relationships between porosity and mechanical properties. Results obtained from synthetic sandstones show that yield stress, cohesion and the angle of friction are linearly proportional to porosity. Our integrated study shows that digital rock technology can provide meaningful parameters for effective upscaling if thermodynamic volume averaging

Fracture evaluation of an in-service piping flaw caused by microbiologically induced corrosion

International Nuclear Information System (INIS)

Rudland, D.L.; Scott, P.M.; Wilkowski, G.M.; Rahman, S.

1996-01-01

A pipe fracture experiment was conducted on a section of 6-inch nominal diameter pipe which was degraded by microbiologically induced corrosion (MIC) at a circumferential girth weld. The pipe was a section of one of the service water piping systems to one of the emergency diesel generators at the Haddam Neck (Connecticut Yankee) plant. The experimental results will help validate future ASME Section XI pipe flaw evaluation criteria for other than Class 1 piping. A critical aspect of this experiment was an assessment of the degree of conservatism embodied in the ASME definition of flaw size. The ASME flaw size definition assumes a rectangular shaped, constant depth flaw with a depth equal to its maximum depth for its entire length. Since most service flaws are irregular in shape, this definition may be overly conservative. Results from several fracture prediction models are compared with the experimental results. These results show that, for this case, the ASME Appendix H criteria significantly underpredicted the experimental maximum moment, while other fracture prediction models provided good predictions when accurate pipe, weld and flaw dimensions were used

[Treatment of multi-segment fracture of complex femoral shaft with instrument-assisted reduction combined with intramedullary interlocking nail fixation].

Science.gov (United States)

Fan, Ke-Jie; Chen, Ke; Ma, Wen-Long; Tian, Ke-Wei; Ye, Ye; Chen, Hong-Gan; Tang, Yan-Feng; Cai, Hong-Min

2018-05-25

To investigate the effect of minimally invasive mini-incision and instrumented reduction combined with interlocking intramedullary nailing in the treatment of patients with multi-segment fracture of complex femoral shaft. From January 2013 to January 2016, 32 patients with multiple fractures segments of femoral shaft were treated with instrumentation-assisted reduction combined with interlocking intramedullary nailing, including 22 males and 10 females with an average age of 45 years old ranging 17 to 68 years old. The time from injured to operation was 5 to 10 days with an average of 7 days. After admission, routine tibial tubercle or supracondylar bone traction was performed. The patient's general condition was evaluated, the operation time and intraoperative blood loss were recorded. According to Thorsen femoral fracture morphology evaluation criteria and Hohl knee function evaluation of postoperative efficacy, postoperative fracture healing, complications and postoperative recovery of limb function were observed. All patients were followed up for 6 to 24 months with an average of 12 months. The operative time ranged from 48 to 76 minutes with an average of 67 min. The intraoperative blood loss was 150 to 400 ml with an average of 220 ml. The surgical incisions all achieved grade A healing. The fractures reached the clinical standard of healing. The fracture healing time ranged from 4.2 to 10.8 months with an average of 5.7 months. There were no nonunion, incision infection and internal fixation fracture, failure and other complications. According to Thorsen femoral fracture morphology evaluation criteria, the result was excellent in 28 cases, good in 3 cases, fair in 1 case. According to Hohl knee function evaluation criteria, the result was excellent in 30 cases, good in 2 cases. Instrument-assisted reduction combined with interlocking intramedullary nail fixation is a safe and effective method for the treatment of complex femoral shaft fractures. It has

Fracture Mechanics

International Nuclear Information System (INIS)

Jang, Dong Il; Jeong, Gyeong Seop; Han, Min Gu

1992-08-01

This book introduces basic theory and analytical solution of fracture mechanics, linear fracture mechanics, non-linear fracture mechanics, dynamic fracture mechanics, environmental fracture and fatigue fracture, application on design fracture mechanics, application on analysis of structural safety, engineering approach method on fracture mechanics, stochastic fracture mechanics, numerical analysis code and fracture toughness test and fracture toughness data. It gives descriptions of fracture mechanics to theory and analysis from application of engineering.

Fractures Due to Gunshot Wounds: Do Retained Bullet Fragments Affect Union?

Science.gov (United States)

Riehl, John T; Connolly, Keith; Haidukewych, George; Koval, Ken

2015-01-01

Many types of projectiles, including modern hollow point bullets, fragment into smaller pieces upon impact, particularly when striking bone. This study was performed to examine the effect on time to union with retained bullet material near a fracture site in cases of gunshot injury. All gunshot injuries operatively treated with internal fixation at a Level 1 Trauma Center between March 2008 and August 2011 were retrospectively reviewed. Retained bullet load near the fracture site was calculated based on percentage of material retained compared to the cortical diameter of the involved bone. Analyses were performed to assess the effect of the lead-cortical ratio and amount of comminution on time to fracture union. Thirty-two patients (34 fractures) met the inclusion criteria, with an equal number of comminuted (17) and non-comminuted fractures (17). Seventeen of 34 fractures (50%) united within 4 months, 16/34 (47%) developed a delayed union, and 1/34 (3%) developed a nonunion requiring revision surgery. Sixteen of 17 fractures (94%) that united by 4 months had a cumulative amount of bullet fragmentation retained near the fracture site of less than 20% of the cortical diameter. Nine out of 10 fractures (90%) with retained fragments near the fracture site was equal to or exceeding 20% of the cortical diameter had delayed or nonunion. Fracture comminution had no effect on time to union. The quantity of retained bullet material near the fracture site was more predictive of the rate of fracture union than was comminution. Fractures with bullet fragmentation equal to or exceeding 20% of the cortical width demonstrated a significantly higher rate of delayed union/nonunion compared to those fractures with less retained bullet material, which may indicate a local cytotoxic effect from lead on bone healing. These findings may influence decisions on timing of secondary surgeries. Level III.

Concepts and possibilities of fracture mechanics for fracture safety assessment

International Nuclear Information System (INIS)

Blauel, J.

1980-01-01

In very tough materials for pressure vessels and pipelines of nuclear plants, cracking begins in a stable manner and only after macroscopic plastic deformations and crack blunting. It is possible to describe this elasto-plastic fracture behaviour and to quantify the safety margin compared to the assessment criteria based on linear elastic stressing and initiation by the concept of the J integral, the crack peak width and the crack resistance Jsub(R) curve. The numerous problems of details still open and the partly very limited validity range should not prevent the further investigation into the great possibilities of this concept and making greater use of the interpretation of large scale tests. (orig./RW) [de

Role of gamma nail in management of pertrochanteric fractures of femur

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Sharma Vipin

2008-01-01

Full Text Available Background: Pertrochanteric fractures which involve trochanteric fractures with varying fracture geometry pose a significant challenge to the treating orthopedic surgeon. The aim of this study is to evaluate the management of pertrochanteric fractures of the femur using gamma nail [Asia pacific (AP]. Materials and Methods: Sixty patients of pertrochanteric fractures were treated by closed reduction internal fixation by gamma nail from 1 January 1993 to 31 December 2000. Four patients were lost to follow-up. The remaining 56 patients were followed for a mean period of 3.2 years (range 2-4 years.The results were evaluated by assessing the patients regarding their clinical and functional outcome at follow-up as per Kyle′s criteria. Results: Peroperative jamming of nail ( n = 1, failed distal locking ( n = 1, superior cut out of lag screw ( n = 1 and postoperative varus malreduction ( n = 1 were the complications observed. End results were excellent in 46.34%, good in 36.58%, fair in 14.64%, poor in 2.43%. Conclusion: Gamma nail in expert hands is a suitable implant for management of pertrochanteric fractures of the femur.

Characterization on the Fracture system in jurassic granitic rocks: Kosung and Yusung areas

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyung Su; Bae, Dae Seok; Kim, Chun Soo; Park, Byung Yoon; Koh, Yong Kweon

2001-03-01

The safety of waste disposal can be achieved by a complete isolation of radioactive wastes from biosphere or by a retardation of nuclide migration to reach an acceptable dose level. For the deep geological disposal of high-level radioactive waste, the potential pathways of nuclide primarily depend on the spatial distribution characteristics of conductive fractures in rock mass. Major key issues in the quantification of fracture system for a disposal site are involved in classification criteria, hydraulic parameters, geometry, field investigation methods etc. This research aims to characterize the spatial distribution characteristics of regional lineaments and background fractures in eastern and western-type granite rock mass.

Characterization on the Fracture system in jurassic granitic rocks: Kosung and Yusung areas

International Nuclear Information System (INIS)

Kim, Kyung Su; Bae, Dae Seok; Kim, Chun Soo; Park, Byung Yoon; Koh, Yong Kweon

2001-03-01

The safety of waste disposal can be achieved by a complete isolation of radioactive wastes from biosphere or by a retardation of nuclide migration to reach an acceptable dose level. For the deep geological disposal of high-level radioactive waste, the potential pathways of nuclide primarily depend on the spatial distribution characteristics of conductive fractures in rock mass. Major key issues in the quantification of fracture system for a disposal site are involved in classification criteria, hydraulic parameters, geometry, field investigation methods etc. This research aims to characterize the spatial distribution characteristics of regional lineaments and background fractures in eastern and western-type granite rock mass

Current status of the quantification of roughness and the peak shear strength criteria for rock joints

Energy Technology Data Exchange (ETDEWEB)

Park, Byoung Yoon; Kang, Chul Hyung

1999-04-01

In order to understand the effects of spent nuclear fuel on the hydraulic behaviour of the rock mass it is necessary to have knowledge about the relationship between the stresses and hydraulic properties of the fractures. The roughness of a fracture surface govern the dilation of the fracture and the displacement of the fracture surface under shear stress. The peak shear strength and hydraulic flow properties of fractures depend very much on the surface roughness. This report describes different methods and techniques used in the characterization of rock joint surfaces and their applications in rock mechanics. Joint roughness is an important factor in the shear resistance of a joint. The joint shear strength shows anisotropic properties due to roughness variation with the shearing direction in direct shear tests. Various shear strength criteria are described in this report. (author)

Transmasseteric anterior parotid approach for condylar fractures: experience of 129 cases.

Science.gov (United States)

Narayanan, Vinod; Ramadorai, Ashok; Ravi, Poornima; Nirvikalpa, Natarajan

2012-07-01

We have evaluated the transmasseteric anterior parotid (TMAP) approach in the treatment of 163 condylar fractures in 129 patients. Ninety-five patients presented with unilateral, and 34 with bilateral, fractures. The inclusion criteria were patient's choice for open reduction and internal fixation, displaced unilateral condylar fractures with occlusal derangement, and displaced bilateral condylar fractures with anterior open bite. Mean (SD) maximum interincisal opening after 3 months was 44(5)mm. There were no differences in lateral movements during the reviews 6 weeks and 3 months postoperatively. Protrusive movement at the end of 3 months was 7(2)mm. All patients achieved functional occlusion identical to the pretraumatic occlusion and good reduction of the condyles. No patient developed temporary or permanent facial palsy, sialocele, salivary fistula, or Frey syndrome. The mean (SD) operating time was 46(11)min. The TMAP approach avoids the complications of incision of the parotid gland, minimises the risk of facial nerve palsy, and offers excellent access to the fractured condyle. Copyright © 2011 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

The use of fracture mechanics for the evaluation of NDE flaw acceptance standards

Energy Technology Data Exchange (ETDEWEB)

Alicino, A; Capurro, E; Ansaldo, Sp; Corvi, A [Ansaldo SpA, Genoa (Italy)

1988-12-31

This document deals with the use of fracture mechanics criteria to evaluate the Non Destructive Examination (NDE) flaw acceptance standards. The communication discusses the general schemes and the guidelines of the activity carried out. (TEC).

Pathologic fracture in childhood and adolescent osteosarcoma: A single-institution experience.

Science.gov (United States)

Haynes, Lindsay; Kaste, Sue C; Ness, Kirsten K; Wu, Jianrong; Ortega-Laureano, Lucia; Bishop, Michael; Neel, Michael; Rao, Bhaskar; Fernandez-Pineda, Israel

2017-04-01

Pathologic fractures occur in 5-10% of pediatric osteosarcoma (OS) cases and have historically been considered a contraindication to limb salvage. Our purpose was to describe the radiographic features of pathologic fracture and examine its impact on local recurrence rates, functional outcomes, and overall survival. We retrospectively analyzed patients at our institution from 1990 to 2015 with pathologic fracture at diagnosis or during neoadjuvant chemotherapy. We selected a control group of 50 OS patients of similar age and gender without pathologic fracture from 1990 to 2015. Functional outcomes were scored using Musculoskeletal Tumor Society criteria. Chi-square test was used for comparative analysis of groups. Thirty-six patients with 37 pathologic fractures form the study cohort. Of patients who received surgery, 18 of 34 patients with fracture underwent amputation compared to 8 of 48 patients in the nonfracture group (P = 0.007). Indications for amputation in fracture patients were tumor size (n = 7), neurovascular involvement (n = 6), and tumor progression during neoadjuvant chemotherapy (n = 5). Only one patient (2.9%) in the fracture group who underwent limb salvage suffered local recurrence. Of patients who received neoadjuvant chemotherapy, 25 of 34 fracture patients showed poor histological response compared to 24 of 47 nonfracture patients (P = 0.044). There was no statistically significant difference in overall survival (P = 0.96). Functional outcomes were significantly lower in fracture patients (median = 17.5) than nonfracture patients (median = 24) (P = 0.023). Radiographic features of pathologic fractures were highly variable in this population. Limb salvage surgery can be performed without increased risk of local recurrence. Patients with pathologic fracture suffer worse functional outcomes but no decrease in overall survival. © 2016 Wiley Periodicals, Inc.

An Experimental Investigation into Failure and Localization Phenomena in the Extension to Shear Fracture Transition in Rock

Science.gov (United States)

Choens, R. C., II; Chester, F. M.; Bauer, S. J.; Flint, G. M.

2014-12-01

Fluid-pressure assisted fracturing can produce mesh and other large, interconnected and complex networks consisting of both extension and shear fractures in various metamorphic, magmatic and tectonic systems. Presently, rock failure criteria for tensile and low-mean compressive stress conditions is poorly defined, although there is accumulating evidence that the transition from extension to shear fracture with increasing mean stress is continuous. We report on the results of experiments designed to document failure criteria, fracture mode, and localization phenomena for several rock types (sandstone, limestone, chalk and marble). Experiments were conducted in triaxial extension using a necked (dogbone) geometry to achieve mixed tension and compression stress states with local component-strain measurements in the failure region. The failure envelope for all rock types is similar, but are poorly described using Griffith or modified Griffith (Coulomb or other) failure criteria. Notably, the mode of fracture changes systematically from pure extension to shear with increase in compressive mean stress and display a continuous change in fracture orientation with respect to principal stress axes. Differential stress and inelastic strain show a systematic increase with increasing mean stress, whereas the axial stress decreases before increasing with increasing mean stress. The stress and strain data are used to analyze elastic and plastic strains leading to failure and compare the experimental results to predictions for localization using constitutive models incorporating on bifurcation theory. Although models are able to describe the stability behavior and onset of localization qualitatively, the models are unable to predict fracture type or orientation. Constitutive models using single or multiple yield surfaces are unable to predict the experimental results, reflecting the difficulty in capturing the changing micromechanisms from extension to shear failure. Sandia

Treatment of Middle Third Humeral Shaft Fractures with Anteromedial Plate Osteosynthesis through an Anterolateral Approach

Directory of Open Access Journals (Sweden)

Kumar BS

2016-03-01

Full Text Available Background: Treatment of humeral shaft fractures has been a subject of debate for many decades. Even though a large majority of humeral shaft fractures can be treated by non operative methods, few conditions like open fractures, polytrauma, ipsilateral humeral shaft and forearm fractures require surgical intervention. The goal of treatment of humeral shaft fractures is to establish union with an acceptable humeral alignment and to restore the patient to pre-injury level of function. The objective was to assess the incidence of radial nerve palsy, non-union and mean time required for in anteromedial plate osteosynthesis with anterolateral approach and also to measure the functional outcome of this procedure. Method: A prospective study was conducted in the Department of Orthopaedics, PESIMSR, Kuppam, Andhra Pradesh, from August 2012 to August 2015 with a total of 54 patients who were operated with anteromedial plate osteosynthesis were included in the study. RodriguezMerchan criteria was used to grade the functional outcome. Results: Of the 54 patients, 28 (58.85% were in the age group of 30-40 years. The most common fracture pattern identified was A3 type (48.14%.The mean (+ SD duration of surgery for anteromedial humeral plating was 53 ± 5.00 minutes. The time taken for the fracture to unite was less than 16 weeks in the majority or 50 patients (92.59%. Four (7.40% patients had delayed union. There was no incidence of iatrogenic radial nerve palsy. Rodriguez – Merchan criteria showed that 37(68.51% of the patients had good and 12 (22.22% had excellent functional outcome.

Finite element simulations and experimental investigations on ductile fracture in cold forging of aluminum alloy

Science.gov (United States)

Amiri, Amir; Nikpour, Amin; Saraeian, Payam

2018-05-01

Forging is one of the manufacturing processes of aluminium parts which has two major categories: called hot and cold forging. In the cold forging, the dimensional and geometrical accuracy of final part is high. However, fracture may occur in some aluminium alloys during the process because of less workability. Fracture in cold forging can be in the form of ductile, brittle or combination of both depending on the alloy type. There are several criteria for predicting fracture in cold forging. In this study, cold forging process of 6063 aluminium alloy for three different parts is simulated in order to predict fracture. The results of numerical simulations of Freudenthal criterion is in conformity with experimental tests.

Crack and fracture behaviour in tough ductile materials

International Nuclear Information System (INIS)

Venter, R.D.; Hoeppner, D.W.

1985-10-01

The report describes various approaches and developments pertaining to the understanding of crack and fracture behaviour in tough ductile materials. The fundamental elastic fracture mechanics concepts based on the concepts of energy, stress field, and displacement are introduced and their interrelationships demonstrated. The extension of these concepts to include elasto-plastic fracture mechanics considerations is reviewed in the context of the preferred options available for the development of appropriate design methodologies. The recommendations of the authors are directed towards the continued development of the J-integral concept. This energy-based concept, in its fundamental form, has a sound theoretical basis and as such offers the possibility of incorporating elasto-plastic fracture mechanics considerations in the crack and fracture behaviour of tough ductile materials. It must however be emphasized that the concise defintion of J becomes increasingly suspect as the crack length increases. J is not a material property, as is J IC , but emerges as a useful empirical parameter which is dependent upon the particular geometry and the loading imposed on the structure. It is proposed that 'lowest bound' J-resistance curves and the associated J-T curves be experimentally developed and employed in the design process. Improvements to these 'lowest bounds' can be developed through extensive analysis of the twin J-CTOA criteria and validation of this approach through near full scale tests

The effect of stress fracture interventions in a single elite infantry training unit (1983-2015).

Science.gov (United States)

Milgrom, Charles; Finestone, Aharon S

2017-10-01

Stress fractures can be seen as an undesired byproduct of demanding physical training. The threshold value of stress that places an individual bone at high risk for stress fracture has not been identified. In a prospective study of stress fractures in 1983, a 31% incidence was found during demanding Israeli infantry basic training by bone scan criteria. Within a subgroup of these recruits, an elite infantry unit was found to have a 40% incidence. Since then and until 2015, eight additional induction companies of the same elite infantry unit were prospectively monitored for stress fractures during their basic training. In all of the studies, stress fracture surveillance and the examining orthopedist were the same. A retrospective review of all nine studies and of eight training changes was performed to look for a temporal trend in stress fracture incidence and to see if these might be related to training changes. There was a statistically significant trend for lower radiological proven stress fractures (p=0.0001) and radiological proven stress fractures plus clinical stress fractures (p=0.0013), as well as lower stress fracture severity by radiological criteria (p=0.0001) between 1983 and 2015. The only training change that was associated, by multivariate logistic regression, with a decreased incidence of stress fracture was restricting training to the authorized training protocol (odds ratio, 3874; 95% CI, 1.526 to 9.931; p=0.004). Increased recruit weight was found by multivariate analysis to be associated with lower stress fracture incidence (odds ratio 1.034; 95% CI, 1.00 to 1.070; p=0.051). Moving the training to a base with flatter terrain and reducing the formal marching distance by 1/3 was associated with a decrease in high grade stress fractures (odds ratio, 10.03; 95% CI, 3.5 to 28.4; p=0.0001). Neither the combined changes of enforcing a seven hour a night sleep regimen, training in more comfortable boots and adding a physical therapist to the unit nor

A CLINICAL STUDY OF PROXIMAL FEMUR LOCKING COMPRESSION PLATE (LCP - PF IN THE MANAGEMENT OF COMMUNITED INTERTROCHANTERIC AND SUBTROCHANTERIC FRACTURES OF THE FEMUR

Directory of Open Access Journals (Sweden)

Hari Babu

2015-10-01

Full Text Available Fractures of proximal femur and hip are relatively common injuries in elderly individuals . The incidence of peritrochanteric and intertrochanteric fracture is also increasing among young population, who sustain high energy trauma Rigid Internal fixation and early mobilization has been the standard method of treatment. A combination of orthopaedic surgery and early postoperative physiotherapy and ambulation is the best approach. The overall goal in the treatment of hip fractures is to return the patient to pre - morbid level of function. AIMS & OBJECTIVE : To analyse the anatomical and f unctional outcome of the treatment with LCP - Proximal femur. METHODOLOGY : The present study consists of 12 adult patients of peritrochanteric factures of femur satisfying the inclusion criteria , treated with Proximal Femoral Locking Compression Plate at S. V. R. R . Govt . General Hospital, Tirupati during the period of nov 2013 to Oct 2015. INCLUSION CRITERIA : Age >18years , comminuted trochanteric and sub trochanteric fractures , Signed written informed consent . EXCLUSION CRITERIA: Inter trochanteric fractures involving piriformis fossa , Compound fractures . Pathological fractures . Any displacement of a femoral neck fracture . A ssociated malignancy. RESULTS : Average age incidence in the present study was 62.7 years. , Predominantly males (75% were affected. , Most cases occurred after a fall 10 (50% cases which was statistically significant , Right side involvement was more common. , Average post - operative stay was 13.5 days. , Out of the 12 cases, evaluated using Salvati - Wilson scoring : 3 cases (25% had good, 8 cases (66.67% fair, 1 case (8.33% had poor score , Average weight bearing time was14.5 weeks , Average union rate was 19.45 weeks.

Considerations on the manner to account for fast fracture risk in the design of PWR vessels

International Nuclear Information System (INIS)

Pellisier-Tanon, A.; Grandemange, J.M.

1985-08-01

The way followed in France for analyzing fast fracture resistance of PWR primary components is the one of a deterministic analysis with safety coefficients imposed in the fracture criteria. The study of margins towards fast fracture of the 900 MWe program vessels undertaken in 1982 includes parametric evaluations of the influence of essential variables. It has stimulated further thoughts on the level of safety to fix in the analysis methodology, on the orientations for the choice of safety factors and on the manner to introduce them in the analysis. A first chapter tries to characterize the French approach in comparison to those of other countries. A second chapter examines the manner according to which safety factors can be introduced in the deterministic analysis. It presents the principle for a logical approach accounting for the interdependency of all factors and variables. It establishes criteria for the selection of defect kind and size for the computation

Model of T-Type Fracture in Coal Fracturing and Analysis of Influence Factors of Fracture Morphology

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Yuwei Li

2018-05-01

Full Text Available Special T-type fractures can be formed when coal is hydraulically fractured and there is currently no relevant theoretical model to calculate and describe them. This paper first establishes the height calculation model of vertical fractures in multi-layered formations and deduces the stress intensity factor (SIF at the upper and lower sides of the fracture in the process of vertical fracture extension. Combined with the fracture tip stress analysis method of fracture mechanics theory, the horizontal bedding is taken into account for tensile and shear failure, and the critical mechanical conditions for the formation of horizontal fracture in coal are obtained. Finally, the model of T-type fracture in coal fracturing is established, and it is verified by fracturing simulation experiments. The model calculation result shows that the increase of vertical fracture height facilitates the increase of horizontal fracture length. The fracture toughness of coal has a significant influence on the length of horizontal fracture and there is a threshold. When the fracture toughness is less than the threshold, the length of horizontal fracture remains unchanged, otherwise, the length of horizontal fracture increases rapidly with the increase of fracture toughness. When the shear strength of the interface between the coalbed and the interlayer increases, the length of the horizontal fracture of the T-type fracture rapidly decreases.

Sandia National Laboratories cask drop test programme: a demonstration of fracture mechanics principles for the prevention of brittle fracture

International Nuclear Information System (INIS)

McConnell, P.; Sorenson, K.B.

1995-01-01

Sandia National Laboratories recently completed a cask drop test programme. The aims of the programme were (1) to demonstrate the applicability of a fracture mechanics-based methodology for ensuring cask integrity, and (2) to assess the viability of using a ferritic materials for cask containment. The programme consisted of four phases: (i) materials characterisation; (ii) non-destructive examination of the cask; (iii) finite element analyses of the drop events; and (iv) a series of drop tests of a ductile iron cask. The first three phases of the programme provided information for fracture mechanics analyses and predictions for the drop test phase. The drop tests were nominally based upon the IAEA 9 m drop height hypothetical accident scenario although one drop test was from 18 m. All tests were performed in the side drop orientation at a temperature of -29 o C. A circumferential, mid-axis flaw was introduced into the cask body for each drop test. Flaw depth ranged from 19 to 76 mm. Steel saddles were welded to the side wall of the cask to enhance the stresses imposed upon the cask in the region of the introduced flaw. The programme demonstrated the applicability of a fracture mechanics methodology for predicting the conditions under which brittle fracture may occur and thereby the utility of fracture mechanics design for ensuring cask structural integrity by ensuring an appropriate margin of safety. Positive assessments of ductile iron for cask containment and the quality of the casting process for producing ductile iron casks were made. The results of this programme have provided data to support IAEA efforts to develop brittle fracture acceptance criteria for cask containment. (author)

Elastic-plastic fracture mechanics for nuclear pressure vessels: a preliminary appraisal

International Nuclear Information System (INIS)

Hahn, G.T.; Broek, D.; Marschall, C.W.; Rosenfield, A.R.; Rybicki, E.F.; Schmueser, D.W.; Stonesifer, R.B.; Kanninen, M.F.

1978-01-01

A research program directed at assessing the margin of safety of flawed nuclear pressure vessels near and beyond general yielding is described. The program has the general objective of developing an elastic-plastic fracture mechanics methodology. The approach is based on the use of finite element models together with experimental results to identify criteria appropriate for the onset of crack extension and for stable crack growth. A number of criteria beyond the conventional LEFM R curve are being evaluated. These include the critical values of the J-integral, its derivative, the crack tip opening angle, the average crack opening angle, a generalized energy release rate, its components and a crack tip force. The optimum fracture criterion for nuclear vessels is being determined by systematic measurements of load extension curves, strain distribution, crack opening displacement, stable crack growth and instability on 'toughness scaled' model materials. Computations have been performed for center cracked panels of a model material (2219-T87 aluminium) for full shear failure. (author)

Epidemiology of open tibia fractures in a population-based database: update on current risk factors and clinical implications.

Science.gov (United States)

Weber, Christian David; Hildebrand, Frank; Kobbe, Philipp; Lefering, Rolf; Sellei, Richard M; Pape, Hans-Christoph

2018-02-02

Open tibia fractures usually occur in high-energy mechanisms and are commonly associated with multiple traumas. The purposes of this study were to define the epidemiology of open tibia fractures in severely injured patients and to evaluate risk factors for major complications. A cohort from a nationwide population-based prospective database was analyzed (TraumaRegister DGU ® ). Inclusion criteria were: (1) open or closed tibia fracture, (2) Injury Severity Score (ISS) ≥ 16 points, (3) age ≥ 16 years, and (4) survival until primary admission. According to the soft tissue status, patients were divided either in the closed (CTF) or into the open fracture (OTF) group. The OTF group was subdivided according to the Gustilo/Anderson classification. Demographic data, injury mechanisms, injury severity, surgical fracture management, hospital and ICU length of stay and systemic complications (e.g., multiple organ failure (MOF), sepsis, mortality) were collected and analyzed by SPSS (Version 23, IBM Inc., NY, USA). Out of 148.498 registered patients between 1/2002 and 12/2013; a total of 4.940 met the inclusion criteria (mean age 46.2 ± 19.4 years, ISS 30.4 ± 12.6 points). The CTF group included 2000 patients (40.5%), whereas 2940 patients (59.5%) sustained open tibia fractures (I°: 49.3%, II°: 27.5%, III°: 23.2%). High-energy trauma was the leading mechanism in case of open fractures. Despite comparable ISS and NISS values in patients with closed and open tibia fractures, open fractures were significantly associated with higher volume resuscitation (p Open tibia fractures are common in multiple trauma patients and are therefore associated with increased resuscitation requirements, more surgical procedures and increased in-hospital length of stay. However, increased systemic complications are not observed if a soft tissue adapted surgical protocol is applied.

Gradient effects on the fracture of inhomogeneous materials

Energy Technology Data Exchange (ETDEWEB)

Becker, Terrence Lee [Univ. of California, Berkeley, CA (United States)

2000-05-01

Functionally Graded Materials (FGMs) have a spatial variation in physical properties that can be tailored to meet the needs of a specific application and/or to minimize internal stresses arising from thermal and elastic mismatch. Modeling these materials as inhomogeneous continua allows assessment of the role of the gradient without requiring detailed knowledge of the microstructure. Motivated by the relative difficulty of obtaining analytical solutions to boundary value problems for FGMs, an accurate finite-element code is developed for obtaining numerical planar and axisymmetric linear thermoelastic solutions. In addition an approximate analytical technique for mapping homogeneous-modulus solutions to those for FGMs is assessed and classes of problems to which it applies accurately are identified. The fracture mechanics analysis of FGMs can be characterized by the classic stress intensities, KI and KII, but there has been scarce progress in understanding the role of the modulus gradient in determining fracture initiation and propagation. To address this question, a statistical fracture model is used to correlate near-tip stresses with brittle fracture initiation behavior. This describes the behavior of a material experiencing fracture initiation away from the crack tip. Widely dispersed zones of fracture initiation sites are expected. Finite-length kinks are analyzed to describe the crack path for continuous crack growth. For kink lengths much shorter than the gradient dimension, a parallel stress term describes the deviation of the kinking angle from that for homogeneous materials. For longer kinks there is a divergence of the kink angle predicted by the maximum energy release rate and the pure opening mode criteria.

Titanium elastic nailing in pediatric femoral diaphyseal fractures

Directory of Open Access Journals (Sweden)

Singh Roop

2006-01-01

Full Text Available Background: The need for operative fixation of pediatric femoral fractures is increasingly being recognised in the present decade. The conventional traction and casting method for management of pediatric femoral fractures is giving way for the operative stabilisation of the fracture. Methods : Thirty five pediatric patients in age group 6-14 years with diaphyseal femoral fractures were stabilised with two titanium nails. Patients were followed up clinically and radiologically for two years. The final results were evaluated using the criteria of Flynn et al. Technical problems and complications associated with the procedure were also analysed. Results : Overall results observed were excellent in 25, satisfactory in 8 and poor in 2 patients. Hospital time averaged 12.30 days in the series. All the fractures healed with an average time to union of 9.6 (6-14.4 weeks. Return to school was early with an average of 7.8 weeks. The soft tissue discomfort near the knee produced by the nails ends was the most common problem encountered. Shortening was observed in three cases and restriction of knee flexion in 5 patients. There was no delayed union, infection or refractures. Per operative technical problems included failure of closed reduction in 2 cases and cork screwing of nails in one case. Conclusion : We believe that with proper operative technique and aftercare TENs may prove to be an ideal implant for pediatric femoral fracture fixation. The most of the complication associated with the procedure are infact features of inexact technique and can be eliminated by strictly adhering to the basic principles and technical aspects.

Laser induced damage and fracture in fused silica vacuum windows

International Nuclear Information System (INIS)

Campbell, J.H.; Hurst, P.A.; Heggins, D.D.; Steele, W.A.; Bumpas, S.E.

1996-11-01

Laser-induced damage, that initiates catastrophic fracture, has been observed in large (≤61 cm dia) fused silica lenses that also serve as vacuum barriers in Nova and Beamlet lasers. If the elastic stored energy in the lens is high enough, the lens will fracture into many pieces (implosion). Three parameters control the degree of fracture in the vacuum barrier window: elastic stored energy (tensile stress), ratio of window thickness to flaw depth, and secondary crack propagation. Fracture experiments were conducted on 15-cm dia fused silica windows that contain surface flaws caused by laser damage. Results, combined with window failure data on Beamlet and Nova, were used to develop design criteria for a ''fail-safe'' lens (that may catastrophically fracture but not implode). Specifically, the window must be made thick enough so that the peak tensile stress is less than 500 psi (3.4 MPa) and the thickness/critical flaw size is less than 6. The air leak through the window fracture and into the vacuum must be rapid enough to reduce the load on the window before secondary crack growth occurs. Finite element stress calculations of a window before and immediately following fracture into two pieces show that the elastic stored energy is redistributed if the fragments ''lock'' in place and thereby bridge the opening. In such cases, the peak stresses at the flaw site can increase, leading to further (i.e. secondary) crack growth

Perioperative vitamin D levels correlate with clinical outcomes after ankle fracture fixation.

Science.gov (United States)

Warner, Stephen J; Garner, Matthew R; Nguyen, Joseph T; Lorich, Dean G

2016-03-01

Hypovitaminosis D is common in patients undergoing orthopaedic trauma surgery. While previous studies have shown that vitamin D levels correlate with functional outcome after hip fracture surgery, the significance of vitamin D levels on outcomes after surgery in other orthopaedic trauma patients is unknown. The purpose of this study was to determine if vitamin D levels correlated with outcomes in ankle fracture patients. We reviewed a prospective registry of patients who underwent operative treatment for ankle fractures from 2003 to 2012. Preoperative serum 25-hydroxyvitamin D (25[OH]D) levels were measured, and the primary and secondary outcomes included foot and ankle outcome scores (FAOS) and ankle range of motion. Data were also collected on patient comorbidities, articular malreductions, and wound complications. Included patients had at least 12 months of clinical outcome data. Ninety-eight patients operatively treated for ankle fractures met our inclusion criteria. Of these 98 patients, 36 (37%) were deficient in vitamin D (ankle fractures, preoperative vitamin D deficiency correlated with inferior clinical outcomes at a minimum of 1 year follow-up. Our study suggests that deficient vitamin D levels may result in worse outcomes in orthopaedic trauma patients recovering from fracture fixation.

Ender’s Nail fixation in paediatric femoral shaft fractures.

Directory of Open Access Journals (Sweden)

Rajeev Dwivedi

2013-12-01

Flynn criteria 34 had excellent and 6 had satisfactory results. No poor results were seen. Conclusion: Ender’s nail fixation can be preferred method of treatment for femoral shaft fractures in age group 5 -15 years as the results are excellent and satisfactory. It is technically simple and can be done in a closed manner. It spares the vascularity and growth plate.

[True/Flex intramedullary nailing for forearm shaft fractures. Long-term results].

Science.gov (United States)

Trlica, J; Počepcov, I; Kočí, J; Frank, M; Holeček, T; Dědek, T

2012-01-01

Presentation of technical experience and the clinical and functional results of intramedullary fixation of forearm shaft fractures. Between January 1994 and December 2009, a total of 96 patients with 144 radial and/or ulnar fractures (ulna, 33; radius,15; both, 48) were treated by nailing (True/Flex®). According to the AO classification there were 22-A, 22-B and 22-C type fractures in 39 (41%), 44 (46%) and 13 (13%).cases, respectively. Of these, 82 (85%) were closed (types: 0, 48; I, 33; II, 1) and 14 (15%) were open (types: I, 13; II, 1; III, 0) fractures. Seventy-eight patients (81%) were followed up and their functional outcomes were evaluated according to the criteria of Anderson et al. The average interval between the operation and final follow-up was 28 months (15 to 96 months) The average time to surgery was 2.2 days (0 to 25 days). Early complications were recorded in 4% of the patients (1x bursitis olecrani; 1x end cup replacement; 1x bending of nails) and late complications in 15% (5x non-union; 2x delay union; 4x bursitis olecrani; 1x ruptured tendon). Bone healing was achieved in 95% of the cases and took on average 16 weeks (7 to 34 weeks). No infection, refracture or synostosis occurred. Primary loss of reduction was recorded in four cases due to distraction in one, bent nails in two and a wrong size of the implant in one; secondary loss of reduction was found in three cases, with two cases of radius shortening and one 10°malrotation. No primary malrotation was recorded, but secondary loss of alignment was seen in the distal part of the radius and the proximal part of the ulna. Functional results according to the Anderson criteria were excellent and good in 87% of the cases. Intramedullary mailing provides good stability to mid- and distal-third shaft fractures of the ulna and mid- and proximalthird shaft fractures of the radius, particularly in AO type A and type B fractures. The technical aspects of the method are analysed in detail in this paper

Review of radiological scoring methods of osteoporotic vertebral fractures for clinical and research settings

Energy Technology Data Exchange (ETDEWEB)

Oei, Ling [Erasmus Medical Center, Department of Internal Medicine, Rotterdam (Netherlands); Erasmus Medical Center, Department of Epidemiology, P.O. Box 2040 Ee21-75, CA, Rotterdam (Netherlands); Netherlands Genomics Initiative (NGI)-sponsored Netherlands Consortium for Healthy Aging (NCHA), Rotterdam (Netherlands); Erasmus Medical Center, Departments of Internal Medicine and Epidemiology, P.O. Box 2040 Ee21-83, CA, Rotterdam (Netherlands); Rivadeneira, Fernando [Erasmus Medical Center, Department of Internal Medicine, Rotterdam (Netherlands); Erasmus Medical Center, Department of Epidemiology, P.O. Box 2040 Ee21-75, CA, Rotterdam (Netherlands); Netherlands Genomics Initiative (NGI)-sponsored Netherlands Consortium for Healthy Aging (NCHA), Rotterdam (Netherlands); Erasmus Medical Center, Departments of Internal Medicine and Epidemiology, P.O. Box 2040 Ee5-79, CA, Rotterdam (Netherlands); Ly, Felisia; Breda, Stephan J. [Erasmus Medical Center, Department of Internal Medicine, Rotterdam (Netherlands); Erasmus Medical Center, Department of Epidemiology, P.O. Box 2040 Ee21-75, CA, Rotterdam (Netherlands); Erasmus Medical Center, Departments of Internal Medicine and Epidemiology, P.O. Box 2040 Ee21-83, CA, Rotterdam (Netherlands); Zillikens, M.C. [Erasmus Medical Center, Department of Internal Medicine, Rotterdam (Netherlands); Netherlands Genomics Initiative (NGI)-sponsored Netherlands Consortium for Healthy Aging (NCHA), Rotterdam (Netherlands); Erasmus Medical Center, Department of Internal Medicine, ' s Gravendijkwal 230, CE, Rotterdam (Netherlands); Hofman, Albert [Erasmus Medical Center, Department of Epidemiology, P.O. Box 2040 Ee21-75, CA, Rotterdam (Netherlands); Netherlands Genomics Initiative (NGI)-sponsored Netherlands Consortium for Healthy Aging (NCHA), Rotterdam (Netherlands); Uitterlinden, Andre G. [Erasmus Medical Center, Department of Internal Medicine, Rotterdam (Netherlands); Erasmus Medical Center, Department of Epidemiology, P.O. Box 2040 Ee21-75, CA, Rotterdam (Netherlands); Netherlands Genomics Initiative (NGI)-sponsored Netherlands Consortium for Healthy Aging (NCHA), Rotterdam (Netherlands); Erasmus Medical Center, Departments of Internal Medicine and Epidemiology, P.O. Box 2040 Ee5-75B, CA, Rotterdam (Netherlands); Krestin, Gabriel P.; Oei, Edwin H.G. [Erasmus Medical Center, Department of Radiology, ' s Gravendijkwal 230, CE, Rotterdam (Netherlands)

2013-02-15

Osteoporosis is the most common metabolic bone disease; vertebral fractures are the most common osteoporotic fractures. Several radiological scoring methods using different criteria for osteoporotic vertebral fractures exist. Quantitative morphometry (QM) uses ratios derived from direct vertebral body height measurements to define fractures. Semi-quantitative (SQ) visual grading is performed according to height and area reduction. The algorithm-based qualitative (ABQ) method introduced a scheme to systematically rule out non-fracture deformities and diagnoses osteoporotic vertebral fractures based on endplate depression. The concordance across methods is currently a matter of debate. This article reviews the most commonly applied standardised radiographic scoring methods for osteoporotic vertebral fractures, attaining an impartial perspective of benefits and limitations. It provides image examples and discusses aspects that facilitate large-scale application, such as automated image analysis software and different imaging investigations. It also reviews the implications of different fracture definitions for scientific research and clinical practice. Accurate standardised scoring methods for assessing osteoporotic vertebral fractures are crucial, considering that differences in definition will have implications for patient care and scientific research. Evaluation of the feasibility and concordance among methods will allow establishing their benefits and limitations, and most importantly, optimise their effectiveness for widespread application. (orig.)

Review of radiological scoring methods of osteoporotic vertebral fractures for clinical and research settings

International Nuclear Information System (INIS)

Oei, Ling; Rivadeneira, Fernando; Ly, Felisia; Breda, Stephan J.; Zillikens, M.C.; Hofman, Albert; Uitterlinden, Andre G.; Krestin, Gabriel P.; Oei, Edwin H.G.

2013-01-01

Osteoporosis is the most common metabolic bone disease; vertebral fractures are the most common osteoporotic fractures. Several radiological scoring methods using different criteria for osteoporotic vertebral fractures exist. Quantitative morphometry (QM) uses ratios derived from direct vertebral body height measurements to define fractures. Semi-quantitative (SQ) visual grading is performed according to height and area reduction. The algorithm-based qualitative (ABQ) method introduced a scheme to systematically rule out non-fracture deformities and diagnoses osteoporotic vertebral fractures based on endplate depression. The concordance across methods is currently a matter of debate. This article reviews the most commonly applied standardised radiographic scoring methods for osteoporotic vertebral fractures, attaining an impartial perspective of benefits and limitations. It provides image examples and discusses aspects that facilitate large-scale application, such as automated image analysis software and different imaging investigations. It also reviews the implications of different fracture definitions for scientific research and clinical practice. Accurate standardised scoring methods for assessing osteoporotic vertebral fractures are crucial, considering that differences in definition will have implications for patient care and scientific research. Evaluation of the feasibility and concordance among methods will allow establishing their benefits and limitations, and most importantly, optimise their effectiveness for widespread application. (orig.)

A GENERALIZED TWO-COMPONENT MODEL OF SOLAR WIND TURBULENCE AND AB INITIO DIFFUSION MEAN-FREE PATHS AND DRIFT LENGTHSCALES OF COSMIC RAYS

Energy Technology Data Exchange (ETDEWEB)

Wiengarten, T.; Fichtner, H.; Kleimann, J.; Scherer, K. [Institut für Theoretische Physik IV, Ruhr-Universität Bochum (Germany); Oughton, S. [Department of Mathematics, University of Waikato, Hamilton 3240 (New Zealand); Engelbrecht, N. E. [Center for Space Research, North-West University, Potchefstroom 2520 (South Africa)

2016-12-10

We extend a two-component model for the evolution of fluctuations in the solar wind plasma so that it is fully three-dimensional (3D) and also coupled self-consistently to the large-scale magnetohydrodynamic equations describing the background solar wind. The two classes of fluctuations considered are a high-frequency parallel-propagating wave-like piece and a low-frequency quasi-two-dimensional component. For both components, the nonlinear dynamics is dominanted by quasi-perpendicular spectral cascades of energy. Driving of the fluctuations by, for example, velocity shear and pickup ions is included. Numerical solutions to the new model are obtained using the Cronos framework, and validated against previous simpler models. Comparing results from the new model with spacecraft measurements, we find improved agreement relative to earlier models that employ prescribed background solar wind fields. Finally, the new results for the wave-like and quasi-two-dimensional fluctuations are used to calculate ab initio diffusion mean-free paths and drift lengthscales for the transport of cosmic rays in the turbulent solar wind.

A GENERALIZED TWO-COMPONENT MODEL OF SOLAR WIND TURBULENCE AND AB INITIO DIFFUSION MEAN-FREE PATHS AND DRIFT LENGTHSCALES OF COSMIC RAYS

International Nuclear Information System (INIS)

Wiengarten, T.; Fichtner, H.; Kleimann, J.; Scherer, K.; Oughton, S.; Engelbrecht, N. E.

2016-01-01

We extend a two-component model for the evolution of fluctuations in the solar wind plasma so that it is fully three-dimensional (3D) and also coupled self-consistently to the large-scale magnetohydrodynamic equations describing the background solar wind. The two classes of fluctuations considered are a high-frequency parallel-propagating wave-like piece and a low-frequency quasi-two-dimensional component. For both components, the nonlinear dynamics is dominanted by quasi-perpendicular spectral cascades of energy. Driving of the fluctuations by, for example, velocity shear and pickup ions is included. Numerical solutions to the new model are obtained using the Cronos framework, and validated against previous simpler models. Comparing results from the new model with spacecraft measurements, we find improved agreement relative to earlier models that employ prescribed background solar wind fields. Finally, the new results for the wave-like and quasi-two-dimensional fluctuations are used to calculate ab initio diffusion mean-free paths and drift lengthscales for the transport of cosmic rays in the turbulent solar wind.

[Curative effect analysis on proximal frmoral nail antirotation for the treatment of femoral intertrochanteric fracture and integrity of lateral trochanteric wall].

Science.gov (United States)

Wei, Jie; Qin, De-an; Guo, Xiu-sheng

2015-06-01

To explore clinical efficacy and key matters for the treatment of femoral intertrochanteric fracture and integrity of lateral trochanteric wall by proximal frmoral nail antirotation (PFNA). From June 2010 to December 2012,210 femoral intertrochanteric fracture patients treated with PFNA were retrospectively analyzed, including 76 males and 134 females aged from 46 to 96 years old with an average of 71 years old. All fracture were caused by injury and classified to type I (5 cases) type II (16 cases), type III (73 cases) and type IV (116 cases) according to Evans classification. The time of getting out of bed, postoperative complications and displacement of screw blade and fracture healing were observed, Baumgaertner criteria were used to evaluate quality of fracture reduction, Harris criteria were used to evaulate hip joint function. All incisions were healed at stage I, no complications occurred except incomplete of lateral trochanteric wall patients without reconstruction, other patients could get out of bed with crutches at one week and all patients discharged from hospital at 10 days after operation. One hundred and seventy-eight patients were followed up from 3 to 17 months with an average of 10 months. One case occurred unhealed fracture displacement caused by screw blade cutting, 2 cases occurred screw blade transfomed to proximal and out femoral head, other patients obtained fracture healing at 12 to 16 weeks after operation. According to Baumgaertner criteria, 130 cases obtained good results, 45 cases acceptable, and 3 poor; while 107 cases obtained excellent results, 65 good, 3 good and 3 poor according to Harris score. PFNA with mechanical advantage of intramedullary fixation has advantsges of stable fixation, shorter operation time, minimally invasive. Satisfied clinical effects could obtained by grasping fixation principle, dealing with negative factors in operation. Intraoperative reconstruction for integrity of lateral trochanteric wall could assure

Unstable intertrochanteric femur fractures in geriatric patients treated with the DLT trochanteric nail.

Science.gov (United States)

Temiz, Aytun; Durak, Aslihan; Atici, Teoman

2015-07-01

To evaluate clinical-functional and radiological results of geriatric patients with unstable intertrochanteric femur fracture treated with intramedullary nail. Thirty-two patients treated with intramedullary nail (DLT trochanteric nail) due to unstable intertrochanteric femur fractures were reviewed retrospectively. Fractures 31-A2 and 31-A3 (AO classification) were evaluated. Operation time, blood loss, and blood transfusion requirements, hospitalization period, time to fracture union were evaluated and perioperative and postoperative complications were recorded. According to the modified Baumgaertner criteria fracture reduction was analyzed radiologically, and nail tip-apex distance was measured. Femoral neck-shaft angle was also evaluated. Harris Hip Score for clinical evaluation and Kyo criteria for walking capacity were used. The mean age was 72 years (65-81), mean follow up time was 18.3 months (12-26). Nineteen patients had type 31-A2 and 13 had type 31-A3 fractures. Mean operation time was 36.3min (25-45), blood loss 185.9ml (100-250). Blood transfusion was required in 7 patients. The average hospitalization duration was 6 days (4-14) while the time to surgery from admission was 2.9 days (2-6). Radiologically, in 21 of the cases fracture reduction was well (65.6%), acceptable in 9 (28.1%), and poor in 2 (6.3%). In early postoperative period, the mean collo-diaphyseal angle was 129.1° (120-140°), mean tip-apex distance was 15.5mm (10-27). The mean Harris Hip Score was 63.4 (38-90). Two patients (6.3%) had excellent, 21 patients (65.6%) had good, 7 patients (21.8%) had moderate, and 2 patients (6.3%) had poor results. Walking capacity in the last follow-up in 20 of the cases (62.5%) was pre-fracture level. While complications were observed in seventeen patients (53.1%) (5 superficial wound infections, 5 fractures of the greater trochanter, 3 cases of secondary varus angulation and 4 cases of heterotopic ossification) none of them required additional surgery

Bimalleolar ankle fracture with proximal fibular fracture

NARCIS (Netherlands)

Colenbrander, R. J.; Struijs, P. A. A.; Ultee, J. M.

2005-01-01

A 56-year-old female patient suffered a bimalleolar ankle fracture with an additional proximal fibular fracture. This is an unusual fracture type, seldom reported in literature. It was operatively treated by open reduction and internal fixation of the lateral malleolar fracture. The proximal fibular

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.

2016-01-01

Purpose 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. Methods Cohort study using Veterans Affairs and Medicare administrative data. Male Veterans (n=5,036,536) aged 50-99 years receiving VA primary care between1999-2009 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 regards to the timing of the events. Results 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, 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, p<0.0001), femur (0.15, p<0.0001), and shoulder (0.11, p<0.0001). Conclusions Pelvic, acetabular, femur, and shoulder fractures 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 use of a composite endpoint to better estimate hip fracture risk. PMID:26151123

[Epidemiology of maxillofacial fractures due to traffic accidents in Medellin (Colombia)].

Science.gov (United States)

Agudelo-Suárez, Andrés A; Duque-Serna, Francisco Levi; Restrepo-Molina, Lucas; Martínez-Herrera, Eliana

2015-09-01

To characterize maxillofacial fractures due to traffic accidents in patients attending the Hospital Universitario San Vicente Fundación (Medellin-Colombia) from 1998 to 2010. A descriptive study (n =1609) was carried out with information from the medical records of patients meeting the inclusion criteria established by the general objective of the study. The variables consisted of sex, age, year, type and number of fractures, and type of vehicle. A descriptive analysis of the variables was performed and the frequency of fractures due to traffic accidents was calculated according to year and sex. Crude and adjusted odds ratios (aOR) were estimated to establish associations among age, type of vehicle, and the presence of two or more fractures with stratification by sex. The frequency of maxillofacial fractures due to traffic accidents increased in 2007 (men: n=198, women: n=35) and decreased from 2008 to 2010 in both sexes. Fractures were more frequent in persons aged <35 years (80%) and in men (82%). The highest frequency of fractures was observed in motorists. Male users of motorcycles (aOR=1.41; confidence interval 95% [95%CI]: 1.02- 1.94) and bicycles (aOR=1.61; 95%CI: 1.01- 2.56) were more likely to report two or more fractures compared with pedestrians, after adjustment for other variables. Most maxillofacial fractures occurred in men and in motorists. Future studies should analyze other determinants affecting the epidemiology of maxillofacial fractures. Strategies should be designed to improve the use of protective elements and drivers' knowledge and practices. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

Outcome of non-operative management of femoral shaft fractures in children

Directory of Open Access Journals (Sweden)

Akinyoola A

2011-01-01

Full Text Available Background: Femoral shaft fractures are common injuries in childhood. There is paucity of information on their presentation and outcome of the available treatment methods in the African population. This study evaluated the outcome of non-operative methods of treatment of femoral shaft fractures in our centre. Patients and Methods: A retrospective review of the database of children aged 14 years and below with femoral shaft fractures treated non-operatively over a 10-year period. Results: A total of 134 patients with 138 fractures met the study criteria. This consisted of 71 boys (mean age = 6.1 years ± SD and 63 girls (mean age = 6.5 years ± SD. Pedestrian vehicular accident was the most common cause of femoral shaft fractures in the study population. The midshaft was the most common site of fractures. There were associated injuries to other parts of the body (especially head injury in 34.3% of the patients. The commonest mode of treatment was skin traction only (87.7%. The mean time to fracture union was 4.9 weeks ± SD (range = 3-15 weeks. The mean length of hospitalisation was 6.7 weeks ± SD (range = 5 days-11 weeks. There was a fairly strong positive correlation between the length of hospitalisation and the presence of associated injuries, especially head injury, upper limb fractures and bilaterality of the fractures. The mean total cost of treatment was #7685 (Naira or $51.2 (range = $14.2-$190. At the last follow up, 97.8% of the fractures united without significant angulation or shortening. Conclusion: The outcome of non-operative treatment of femoral shaft fractures in our setting is comparable to the results of other workers. Methods of treatment that shorten the length of hospitalisation without unduly increasing cost should be encouraged.

Foal Fractures: Osteochondral Fragmentation, Proximal Sesamoid Bone Fractures/Sesamoiditis, and Distal Phalanx Fractures.

Science.gov (United States)

Reesink, Heidi L

2017-08-01

Foals are susceptible to many of the same types of fractures as adult horses, often secondary to external sources of trauma. In addition, some types of fractures are specific to foals and occur routinely in horses under 1 year of age. These foal-specific fractures may be due to the unique musculoskeletal properties of the developing animal and may present with distinct clinical signs. Treatment plans and prognoses are tailored specifically to young animals. Common fractures not affecting the long bones in foals are discussed in this article, including osteochondral fragmentation, proximal sesamoid bone fractures/sesamoiditis, and distal phalanx fractures. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of root radius, stress, crack growth and rate on fracture instability

Energy Technology Data Exchange (ETDEWEB)

McClintock, F A

1965-01-01

Of various criteria for fracture at the root of a notch, the energy, local stress, and displacement criteria have limited validity. More appropriate is the history of both stress and strain over a small region ahead of the crack, as required for fracture by the coalescence of holes. Expressions are given for crack initiation, growth, and subsequent instability in anti-plane strain of a nonhardening material. Instability is shown to depend primarily on those strain increments arising from crack growth at constant load rather than on those from increasing load at constant crack length. Thus final instability conditions are similar for single and double- ended cracks, round notches, and cracks cut under constant load. Round notches may give instability, restabilization and final instability. The growth and coalescence of holes in front of a crack in a linearly viscous material is studied for both tensile and anti-plant-strain cracks. The absence of residual strain eliminates instability, but the crack continually accelerates. (26 refs.)

Effect of whole-body vibration exercise in preventing falls and fractures

DEFF Research Database (Denmark)

Jepsen, Ditte Beck; Thomsen, Katja; Hansen, Stinus

2017-01-01

OBJECTIVE: To investigate the effect of whole-body vibration exercise (WBV) on fracture risk in adults ≥50 years of age. DESIGN: A systematic review and meta-analysis calculating relative risk ratios, fall rate ratio and absolute weighted mean difference using random effects models. Heterogeneity...... of retrieved publications. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Randomised controlled trials examining the effect of WBV on fracture risk in adults ≥50 years of age. The primary outcomes were fractures, fall rates and the proportion of participants who fell. Secondary outcomes were bone mineral density......2=24%) (low quality of evidence). Finally, moderate to low quality of evidence showed no overall effect on BMD and only sparse data were available regarding microarchitecture parameters, bone turnover markers and BUA. CONCLUSIONS: WBV reduces fall rate but seems to have no overall effect on BMD...

Prestressed concrete reactor vessels: review of design and failure criteria

International Nuclear Information System (INIS)

Endebrock, E.G.

1975-03-01

The design and failure criteria of prestressed concrete reactor vessels (PCRVs) are reviewed along with the analysis methods. The mechanical properties of concrete under multiaxial stresses are not adequately quantified or described to permit an accurate analysis of a PCRV. Structural analysis of PCRVs almost universally utilizes a finite element which encounters difficulties in numerical solution of the governing equations and in treatment of fractured elements. (U.S.)

On Necking, Fracture and Localization of Plastic Flow in Austenitic Stainless Steel Sheets

International Nuclear Information System (INIS)

Korhonen, A. S.; Manninen, T.; Kanervo, K.

2007-01-01

The forming limits of austenitic stainless steel sheets were studied in this work. It was found that the observed limit of straining in stretch forming, when both of the principal stresses are positive, is not set by localized necking, but instead by inclined shearing fracture in the through thickness direction. It appears that the forming limits of austenitic stainless steels may be predicted fairly well by using the classical localized and diffuse necking criteria developed by Hill. The strain path-dependence may be accounted for by integrating the effective strain along the strain path. The fracture criteria of Rice and Tracey and Cockcroft, Latham and Oh were also studied. The results were in qualitative agreement with the experimental observations. Recent experiments with high-velocity electrohydraulic forming of austenitic stainless steels revealed localized necks in stretch formed parts, which are not commonly observed in conventionally formed sheet metal parts

A study on the characteristics of site-scale fracture system in granite and volcanic rock

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyung Su; Kim, Chun Soo; Bae, Dae Seok; Park, Byoung Yoon; Koh, Young Kown [Korea Atomic Energy Research Institute, Taejeon (Korea)

2000-03-01

The safety of waste disposal can be achieved by a complete isolation of radioactive wastes from biosphere or by a retardation of nuclide migration to reach an acceptable dose level. For the deep geological disposal of high-level radioactive waste, the potential pathways of nuclide primarily depend on the spatial distribution characteristics of conductive fractures. Major key issues in the quantification of fracture system for a disposal site are involved in classification criteria, hydraulic parameters, geometry, field investigation methods etc. This research aims to characterize the spatial distribution characteristics of conductive fractures in granite and volcanic rock mass. 10 refs., 32 figs., 13 tabs. (Author)

Failed Surgical Management of Acute Proximal Fifth Metatarsal (Jones) Fractures: A Retrospective Case Series and Literature Review.

Science.gov (United States)

Granata, Jaymes D; Berlet, Gregory C; Philbin, Terrence M; Jones, Grant; Kaeding, Christopher C; Peterson, Kyle S

2015-12-01

Nonunion, delayed union, and refracture after operative treatment of acute proximal fifth metatarsal fractures in athletes is uncommon. This study was a failure analysis of operatively managed acute proximal fifth metatarsal fractures in healthy athletes. We identified 149 patients who underwent operative treatment for fifth metatarsal fractures. Inclusion criteria isolated skeletally mature, athletic patients under the age of 40 with a minimum of 1-year follow-up. Patients were excluded with tuberosity fractures, fractures distal to the proximal metaphyseal-diaphyseal region of the fifth metatarsal, multiple fractures or operative procedures, fractures initially treated conservatively, and medical comorbidities/risk factors for nonunion. Fifty-five patients met the inclusion/exclusion criteria. Four (7.3%) patients required a secondary operative procedure due to refracture. The average time to refracture was 8 months. All refractures were associated with bent screws and occurred in male patients who participated in professional basketball, professional volleyball, and college football. The average time for release to progressive weight-bearing was 6 weeks. Three patients were revised to a bigger size screw and went on to union. One patient was revised to the same-sized screw and required a second revision surgery for nonunion. All failures were refractures in competitive athletes who were initially treated with small diameter solid or cannulated stainless steel screws. The failures were not associated with early postoperative weight-bearing protocol. Maximizing initial fixation stiffness may decrease the late failure rate in competitive athletes. More clinical studies are needed to better understand risk factors for failure after screw fixation in the competitive, athletic population. Prognostic, Level IV: Case series. © 2015 The Author(s).

CURBSIDE CONSULTATION IN FRACTURE MANAGEMENT: 49 CLINICAL QUESTIONS

Directory of Open Access Journals (Sweden)

Walter W. Virkus

2008-12-01

Full Text Available DESCRIPTION: A user-friendly, unique resource for the treatment of fractures designed in a casual questions and answers format which provides basic knowledge, current information and evidence based expert advices enhanced by images and diagrams and supported by ref-erences.PURPOSE: Designing this book the editor has aimed to prepare not only a source of current knowledge and opin-ions by experienced authors in fracture management for decision making in daily practice but also a brief refer-ence and useful educational resource in orthopedic trauma surgery.FEATURES: Three Sections are composed of 49 sub-jects in a form of the answers of frequently asked ques-tions richly illustrated by images and diagrams and in-cluding references at the end of each subject.The Section I is “UPPER EXTREMITIES” including: Neck fracture; Humerus shaft fracture; Management of radial nerve palsy associated with humeral fracture; Clavicle fractures; Elbow fractures in children; Fasciot-omy technic of the forearm; Distal radius fracture; Indica-tions of radial head replacement, Femur and humeral shaft fractures; Treatment of posterolateral elbow dislocation; The Section II is “LOWER EXTREMITIES” including : Femur fractures; Pelvic fractures; Life threatening pelvic fractures; Decision for surgical treatment in pelvic frac-tures; Treatment of anterior fracture of femoral head and hip joint incongruity; Management of a displaced femoral neck fracture in young patient in ER; Elder patients with displaced femoral head fracture; Patella and tibial plateau fractures; Criteria for compartment syndromes in the tibia; Tricks in nailing proximal and distal tibial fractures; Surgical management of distal tibia spiral fracture in middle aged women; Pilon fracture; Management of syn-desmotic screws in adult patient; The management of minimally displaced posterior malleol in three malleolar fractures; Postoperative management of bimalleolar frac-tures; Management of minimally

Assessment of trochanteric osteotomy fragment union after acetabular fracture surgery.

Science.gov (United States)

Dubina, Andrew G; Wickramaratne, Niluka; O'Toole, Robert V; Manson, Theodore T

2017-02-01

Trochanteric osteotomies are performed in conjunction with standard approaches to improve surgical exposure during open reduction and internal fixation (ORIF) of acetabular fractures. The literature on total hip arthroplasty reports nonunion rates as high as 30% associated with trochanteric osteotomies; however, few data exist regarding the outcomes of trochanteric osteotomies for acetabular fracture surgery. Our hypotheses were 1) patients receiving trochanteric osteotomies during ORIF of acetabular fractures have a low rate of nonunion of the osteotomy fragment, and 2) hip abduction precautions are not necessary with digastric type osteotomies. A retrospective review was conducted to identify patients with acetabular fractures between July 2002 and June 2010 (n=734 fractures) who required trochanteric osteotomies (n=64, 9% of fractures). Forty-seven met inclusion criteria of adequate follow-up (>56days). No excluded patient experienced a complication. Fractures were classified using the Letournel-Judet classification system. Only seven (20%) of 35 patients who received digastric osteotomies had hip abduction precautions applied during the postoperative period. All study patients were shown to have radiographic union at the trochanteric osteotomy site (100% union rate, n=47). Hip abduction precautions intended to protect the osteotomy site and reduce the risk of nonunion and fixation failure were infrequently applied to patients with digastric osteotomies (20%) in this cohort. Multiple protective factors against nonunion were present in this study population compared with previous arthroplasty studies from other institutions. Trochanteric osteotomies are not associated with a significant nonunion rate, and digastric osteotomies might be safely managed without hip abduction precautions. Copyright © 2016. Published by Elsevier Ltd.

Numerical Analysis of AHSS Fracture in a Stretch-bending Test

Science.gov (United States)

Luo, Meng; Chen, Xiaoming; Shi, Ming F.; Shih, Hua-Chu

2010-06-01

Advanced High Strength Steels (AHSS) are increasingly used in the automotive industry due to their superior strength and substantial weight reduction advantage. However, their limited ductility gives rise to numerous manufacturing issues. One of them is the so-called `shear fracture' often observed on tight radii during stamping processes. Since traditional approaches, such as the Forming Limit Diagram (FLD), are unable to predict this type of fracture, efforts have been made to develop failure criteria that can predict shear fractures. In this paper, a recently developed Modified Mohr-Coulomb (MMC) ductile fracture criterion[1] is adopted to analyze the failure behavior of a Dual Phase (DP) steel sheet during stretch bending operations. The plasticity and ductile fracture of the present sheet are fully characterized by the Hill'48 orthotropic model and the MMC fracture model respectively. Finite Element models with three different element types (3D, shell and plane strain) were built for a Stretch Forming Simulator (SFS) test and numerical simulations with four different R/t ratios (die radius normalized by sheet thickness) were performed. It has been shown that the 3D and shell element models can accurately predict the failure location/mode, the upper die load-displacement responses as well as the wall stress and wrap angle at the onset of fracture for all R/t ratios. Furthermore, a series of parametric studies were conducted on the 3D element model, and the effects of tension level (clamping distance) and tooling friction on the failure modes/locations were investigated.

Acetabular Fracture

Directory of Open Access Journals (Sweden)

Chad Correa

2017-09-01

Full Text Available History of present illness: A 77-year-old female presented to her primary care physician (PCP with right hip pain after a mechanical fall. She did not lose consciousness or have any other traumatic injuries. She was unable to ambulate post-fall, so X-rays were ordered by her PCP. Her X-rays were concerning for a right acetabular fracture (see purple arrows, so the patient was referred to the emergency department where a computed tomography (CT scan was ordered. Significant findings: The non-contrast CT images show a minimally displaced comminuted fracture of the right acetabulum involving the acetabular roof, medial and anterior walls (red arrows, with associated obturator muscle hematoma (blue oval. Discussion: Acetabular fractures are quite rare. There are 37 pelvic fractures per 100,000 people in the United States annually, and only 10% of these involve the acetabulum. They occur more frequently in the elderly totaling an estimated 4,000 per year. High-energy trauma is the primary cause of acetabular fractures in younger individuals and these fractures are commonly associated with other fractures and pelvic ring disruptions. Fractures secondary to moderate or minimal trauma are increasingly of concern in patients of advanced age.1 Classification of acetabular fractures can be challenging. However, the approach can be simplified by remembering the three basic types of acetabular fractures (column, transverse, and wall and their corresponding radiologic views. First, column fractures should be evaluated with coronally oriented CT images. This type of fracture demonstrates a coronal fracture line running caudad to craniad, essentially breaking the acetabulum into two halves: a front half and a back half. Secondly, transverse fractures should be evaluated by sagittally oriented CT images. By definition, a transverse fracture separates the acetabulum into superior and inferior halves with the fracture line extending from anterior to posterior

Differing approaches to falls and fracture prevention between Australia and Colombia

Science.gov (United States)

Gomez, Fernando; Curcio, Carmen Lucia; Suriyaarachchi, Pushpa; Demontiero, Oddom; Duque, Gustavo

2013-01-01

Falls and fractures are major causes of morbidity and mortality in older people. More importantly, previous falls and/or fractures are the most important predictors of further events. Therefore, secondary prevention programs for falls and fractures are highly needed. However, the question is whether a secondary prevention model should focus on falls prevention alone or should be implemented in combination with fracture prevention. By comparing a falls prevention clinic in Manizales (Colombia) versus a falls and fracture prevention clinic in Sydney (Australia), the objective was to identify similarities and differences between these two programs and to propose an integrated model of care for secondary prevention of fall and fractures. A comparative study of services was performed using an internationally agreed taxonomy. Service provision was compared against benchmarks set by the National Institute for Health and Clinical Excellence (NICE) and previous reports in the literature. Comparison included organization, administration, client characteristics, and interventions. Several similarities and a number of differences that could be easily unified into a single model are reported here. Similarities included population, a multidisciplinary team, and a multifactorial assessment and intervention. Differences were eligibility criteria, a bone health assessment component, and the therapeutic interventions most commonly used at each site. In Australia, bone health assessment is reinforced whereas in Colombia dizziness assessment and management is pivotal. The authors propose that falls clinic services should be operationally linked to osteoporosis services such as a “falls and fracture prevention clinic,” which would facilitate a comprehensive intervention to prevent falls and fractures in older persons. PMID:23378748

Open versus closed reduction: mandibular condylar fractures in children.

Science.gov (United States)

Chrcanovic, Bruno Ramos

2012-09-01

The purpose of the study was to review the literature regarding the evolution of current thoughts on management of mandibular condylar fractures (MCFs) in children. An electronic search in PubMed was undertaken in May 2012. The titles and abstracts from these results were read to identify studies within the selection criteria. Eligibility criteria included studies published in English or German from the last 20 years (from 1992 onwards) reporting clinical series of MCFs in children and adolescents until the age of 18. The search strategy initially identified 542 studies. The references from 1992 onwards totaled 339 articles. Twenty-seven studies were identified without repetition within the selection criteria. Additional hand-searching yielded two additional papers. Pediatric MCFs require thoughtful consideration in management to avoid significant growth disturbance. Early treatment is indicated in order to improve the chances for favorable development. Long-term follow-up is required, in order to properly treat late complications that may appear. Coronal computed tomography is helpful in substantiating the correct final diagnosis. Many studies show that conservative treatment (CTR) has satisfactory long-term outcome of jaw function, occlusion, and facial esthetics, despite a high frequency of radiological aberrations. Surgery before puberty should be reserved for exceptional cases such as missile injuries, in cases with extensive dislocation and lack of contact between the fragments, in cases with multiple midfacial fractures, in which the mandible has to serve as a guide to reposition the midfacial bones, and in cases which the dislocation of the fractured stump creates a functional impediment that cannot be resolved by CTR. As the craniofacial skeleton becomes more adult-like in its form at about 12 years of age, the decreased remodeling capacity in the adolescents may occasionally result in abnormally shaped condylar heads or shortened ramus heights that may

Missed Fractures in Infants Presenting to the Emergency Department With Fussiness.

Science.gov (United States)

Kondis, Jamie S; Muenzer, Jared; Luhmann, Janet D

2017-08-01

The aim of this study was to evaluate incidence of prior fussy emergency visits in infants with subsequently diagnosed fractures suggestive of abuse. This was a retrospective chart review of infants younger than 6 months who presented to the pediatric emergency department (ED) between January 1, 2006, and December 31, 2011. Inclusion criteria included age 0 to 6 months, discharge diagnosis including "fracture," "broken" (or break), or "trauma" or any child abuse diagnosis or chief complaint of "fussy" or "crying" as documented in the electronic medical record by the triage nurse. Three thousand seven hundred thirty-two charts were reviewed, and 279 infants with fractures were identified. Eighteen (6.5%) of 279 infants had a prior ED visit for fussiness without an obvious source. Of these, 2 had a witnessed event causing their fracture, and therefore the fracture was not considered concerning for abuse. The remaining 16 had fractures concerning for abuse. Mean age was 2.5 (SD, 1.2) months. Fifteen (83%) of 18 infants were 3 months or younger at the time of the fussy visit. The mean interval between the first and second ED visits was 27 days (median, 20 days). Thirty-nine percent were evaluated by a pediatric emergency medicine-trained physician during their initial fussy visit, whereas 78% were evaluated by pediatric emergency medicine-trained physician during their subsequent visit. Most common injuries were multiple types of fractures followed by extremity and rib fractures. Fractures concerning for child abuse are an important cause of unexplained fussiness in infants presenting to the pediatric ED. A high index of suspicion is essential for prompt diagnosis and likely prevention of other abuse.

Double take--fracture fishing in accident and emergency practice.

Science.gov (United States)

Hyland-McGuire, P; Guly, H R; Hughes, P M

1997-03-01

To investigate conditions where, after initially negative plain x rays following trauma, there subsequently proves to be fracture, and to explore ways in which the management might be improved. A 16 month prospective study. Patient details were collected from accident and emergency (A&E) review clinics and returns, A&E ward admissions, correspondence from other services, and discussions at a weekly clinicoradiological conference. The inclusion criteria comprised A&E trauma patients with normal initial plain x rays and proven fractures on subsequent imaging for the same patient event. A large A&E department seeing 65,000 new attendances per annum with full back up services. 55 cases were identified: 41 fractures were identified on subsequent plain x ray, six on bone scan, six on CAT scan, and two on MRI scan. The commonest regions involved were the wrist, pelvis/hip, ankle/foot, and leg. Follow up had not been arranged at the initial attendance in 17 instances and between two and 135 days were required for definitive fracture recognition. All but nine patients required alteration in treatment because of fracture detection. Clinical suspicion of fracture at initial A&E attendance should prompt organised follow up even in the face of normal plain x rays. Consideration should be given to alternative imaging techniques which may have a higher resolution than plain x rays. Close corroboration between A&E and radiology departments has benefits in patient care in this group of patients and may lead to a reduction in functional disability and litigation.

A new system for severity scoring of facial fractures: development and validation.

Science.gov (United States)

Catapano, Joseph; Fialkov, Jeffrey A; Binhammer, Paul A; McMillan, Catherine; Antonyshyn, Oleh M

2010-07-01

Facial fractures are often the result of high-velocity trauma, causing skeletal disruption affecting multiple anatomic sites to varying degrees. Although several widely accepted classification systems exist, these are mostly region-specific and differ in the classification criteria used, making it impossible to uniformly and comprehensively document facial fracture patterns. Furthermore, a widely accepted system that is able to provide a final summary measure of fracture severity does not exist, making it difficult to investigate the epidemiologic data surrounding facial fracture severity. In this study, a comprehensive method for panfacial fracture documentation and severity measurement is proposed and validated through a retrospective analysis of 63 patients operated on for acute facial fracture. The severity scale was validated through statistical analysis of correlation with surrogate markers of severity (operating room procedure time and number of implants). Spearman correlation coefficients were calculated, and a statistically significant correlation was found between severity score and both number of implants and operating room procedure time (R = 0.92790 and R = 0.68157, respectively). Intraclass correlation coefficients were calculated to assess intrarater and interrater reliabilities of the severity scale and were found to be high (0.97 and 0.99, respectively). This severity scale provides a valuable, validated research tool for the investigation of facial fracture severity across patient populations, allowing for systematic evaluation of facial fracture outcomes, cost-benefit analysis, and objective analysis of the effect of specific interventions.

Open Reduction and Internal Fixation of displaced Supracondylar Fractures of Humerus with Crossed K-wires via Medial Approach

Directory of Open Access Journals (Sweden)

S Hussain

2014-07-01

Full Text Available This study aimed at evaluating the medial approach for open reduction and internal fixation of Gartland type 3 displaced supracondylar fractures of humerus in children. A prospective, single centre study of on displaced supracondylar humerus fractures in 42 children was carried out at our institute. All fractures were managed with open reduction and internal fixation with crossed K-wires via medial approach. The mean follow-up was 12 months and patients were assessed according to Flynn’s criteria. No patients had post-operative ulnar nerve injury. Cubitus varus was not seen in any patient. Superficial pin tract infection occurred in three patients that subsided with anti-septic dressings and antibiotics. No deep infection occurred. 88.09 % patients showed satisfactory results as per Flynn’s criteria. The medial approach provides an excellent view of the supracondylar area. The approach is convenient due to a lower risk for ulnar nerve injury and better acceptability of the medial incisional scar.

[Osteoarthritic changes in hip joint in patients with fractures of femoral neck].

Science.gov (United States)

Kravtsov, Vladimir; Saranga, Dan; Kidron, Debora

2013-06-01

Fractures of proximal femur are common among elderly people. They are associated with considerable morbidity and mortality. Identification of etiopathogenetic factors associated with fractures might facilitate prevention. Osteoporosis is commonly present in the heads of femurs. The prevalence of osteoarthritic changes in hip joints is controversial. Some authorities report low prevalence and even speculate on the protective effect of osteoarthritis against fractures. The goal of the study was to examine the association between osteoarthritic changes (radiologic and histologic) and fractures of the neck of the femur. The patient population included 41 patients undergoing replacement of femoral head for subcapital fracture; their ages ranged from 61 - 93 years of age. Radiologic criteria for osteoarthritis included: (a)narrowing of joint space (b) subchondral sclerosis (c) deformation of head of femur (d) subchondra cysts and (e] osteophytes. Osteoarthritic changes, usually mild, were present in 22 (54%) patients, regardless of age and gender The frequency of radioLogical changes was similar to the general population. HistoLogic findings included subchondral fibrosis and subchondral cysts. Mild subchondral fibrosis was present in 78% of cases. The findings support lack of association between osteoarthritic changes in hip joint and fracture of proximal femur, without a protective effect.

Treatment of high-energy pilon fractures using the ILIZAROV treatment.

Science.gov (United States)

Osman, Walid; Alaya, Zeineb; Kaziz, Hamdi; Hassini, Lassad; Braiki, Meriem; Naouar, Nader; Ben Ayeche, Mohamed Laaziz

2017-01-01

The management of high-energy pilon fractures is still controversial. Open reduction and internal fixation are often associated with serious complications. Various methods have been used to treat these injuries, with variable results. The aim of this retrospective study was to analyze the clinical and radiographic outcome of the ILIZAROV technique in patients with high-energy pilon fractures. Thirty cases of distal tibia epiphysis fractures (pilon fractures) were managed from 1999 to 2012. The study group included 5 cases of open fractures. The mean age was 47 years. According to Rüedi and Algower classification; 11 fractures were type II, and 19 type III. All fractures were a consequence of high-energy trauma. Fractures of the lower fibula were present in 28 of the patients. An external Fixator was applied for open fractures. Closed injuries were operated on 3 to 13 days after injury, with an average of 8 days. The mean follow-up was 48 months. All fractures united. The external fixator was removed after a mean of 22 weeks (10 - 28 weeks). Two patients with a type III fracture had a delayed union and were treated with corticotomy and dynamisation of the ILIZAROV fixator. Only one secondary displacement of a type III fracture was noted after two months and was treated by adjuction of 2 olive wires. There were no cases of osteomyelitis or deep infections. Pin-tract infections occurred in ten patients. We had not any case of nervous injury due to introduction of the pins. Using radiological criteria for assessement of reduction of the articular fragments, there was excellent and good restoration of articular structure in 24 cases. The average American Orthopeadic Foot and Ankle Society ankle-hind foot score was excellent in 16, good in 6, fair in 6 and poor in 2. Soft tissue healing occurred without need for plastic surgery in all cases. The movements of the ankle ranged from 0 to 20° of dorsiflexion and 5° to 40° of plantar flexion. Twenty patients had gone back

Modelling of ductile and cleavage fracture by local approach

International Nuclear Information System (INIS)

Samal, M.K.; Dutta, B.K.; Kushwaha, H.S.

2000-08-01

This report describes the modelling of ductile and cleavage fracture processes by local approach. It is now well known that the conventional fracture mechanics method based on single parameter criteria is not adequate to model the fracture processes. It is because of the existence of effect of size and geometry of flaw, loading type and rate on the fracture resistance behaviour of any structure. Hence, it is questionable to use same fracture resistance curves as determined from standard tests in the analysis of real life components because of existence of all the above effects. So, there is need to have a method in which the parameters used for the analysis will be true material properties, i.e. independent of geometry and size. One of the solutions to the above problem is the use of local approaches. These approaches have been extensively studied and applied to different materials (including SA33 Gr.6) in this report. Each method has been studied and reported in a separate section. This report has been divided into five sections. Section-I gives a brief review of the fundamentals of fracture process. Section-II deals with modelling of ductile fracture by locally uncoupled type of models. In this section, the critical cavity growth parameters of the different models have been determined for the primary heat transport (PHT) piping material of Indian pressurised heavy water reactor (PHWR). A comparative study has been done among different models. The dependency of the critical parameters on stress triaxiality factor has also been studied. It is observed that Rice and Tracey's model is the most suitable one. But, its parameters are not fully independent of triaxiality factor. For this purpose, a modification to Rice and Tracery's model is suggested in Section-III. Section-IV deals with modelling of ductile fracture process by locally coupled type of models. Section-V deals with the modelling of cleavage fracture process by Beremins model, which is based on Weibulls

Modeling of the fracture behavior of spot welds using advanced micro-mechanical damage models

International Nuclear Information System (INIS)

Sommer, Silke

2010-01-01

This paper presents the modeling of deformation and fracture behavior of resistance spot welded joints in DP600 steel sheets. Spot welding is still the most commonly used joining technique in automotive engineering. In overloading situations like crash joints are often the weakest link in a structure. For those reasons, crash simulations need reliable and applicable tools to predict the load bearing capacity of spot welded components. Two series of component tests with different spot weld diameters have shown that the diameter of the weld nugget is the main influencing factor affecting fracture mode (interfacial or pull-out fracture), load bearing capacity and energy absorption. In order to find a correlation between nugget diameter, load bearing capacity and fracture mode, the spot welds are simulated with detailed finite element models containing base metal, heat affected zone and weld metal in lap-shear loading conditions. The change in fracture mode from interfacial to pull-out or peel-out fracture with growing nugget diameter under lap-shear loading was successfully modeled using the Gologanu-Leblond model in combination with the fracture criteria of Thomason and Embury. A small nugget diameter is identified to be the main cause for interfacial fracture. In good agreement with experimental observations, the calculated pull-out fracture initiates in the base metal at the boundary to the heat affected zone.

A study of radiological features of healing in long bone fractures among infants less than a year

Energy Technology Data Exchange (ETDEWEB)

Warner, Christopher; Miller, Angie; Weinman, Jason; Fadell, Michael [Children' s Hospital Colorado, Department of Radiology, Aurora, CO (United States); Maguire, Sabine; Trefan, Laszlo [Cardiff University, Institute of Primary Care and Child Health, Cardiff (United Kingdom)

2017-03-15

To create a timetable for dating long bone fractures in infants aged less than 1 year using previously defined radiographic signs of fracture healing. A retrospective cross-sectional time series of long bone fractures in infants aged less than 1 year was conducted from 2006 to 2013. After exclusion criteria were applied 59 digital image series were available for review from 40 infants. Utilizing published criteria for dating fractures, the presence or absence of four pre-defined features of healing was scored: periosteal reaction, callus, bridging, and remodeling. Three radiologists independently scored radiographs with a 3-point scale, marking each feature as present, absent, or equivocal. The times in days when features were first seen, peaked (feature agreed present in >40% of images), and last seen were noted. Statistical analysis using free marginal kappa was conducted. The level of agreement among the three radiologists was high (0.64-0.85). The sequence in which the features were seen was: periosteal reaction range 7-130 (present in the majority of cases between 9 and 49 days); callus range 9-130 (present in the majority of cases between days 9-26); bridging range 15-130 (seen in the majority of cases between 15 and 67 days); remodeling range 51-247 days. This study provides a timetable of radiological features of long bone healing among young infants for the first time. Dating of incomplete long bone fractures is challenging, beyond the presence of periosteal reaction, but a consistent sequence of changes is present in complete fractures. (orig.)

Closed Versus Open Supracondylar Fractures of the Humerus in Children: A Comparison of Clinical and Radiographic Presentation and Results.

Science.gov (United States)

Lewine, Eliza; Kim, Jaehon M; Miller, Patricia E; Waters, Peter M; Mahan, Susan T; Snyder, Brian; Hedequist, Daniel; Bae, Donald S

2018-02-01

The purpose of this investigation was to compare the presentation and postoperative results of children treated for open and closed, completely displaced type III supracondylar humerus fractures (SCFs). Thirty patients with open and 66 patients with closed, completely displaced type III SCFs were evaluated. Open fractures underwent irrigation and debridement, and all patients were treated by open or closed reduction and pin fixation. Medical records were reviewed to obtain demographic information as well as preoperative and postoperative clinical data regarding mechanism of injury, neurovascular status, associated injuries, postoperative range of motion, infections, and pain. Radiographs were evaluated to quantify displacement, Baumann's angle, humeral capitellar angle, position of the anterior humeral line, and adequacy of reduction. Outcomes were assessed using Flynn criteria. Mean clinical follow-up for the open and closed fracture groups was 8.9 and 5.7 months, respectively. Both groups were similar with respect to age, sex distribution, weight and body mass index, laterality of involvement, and mechanism of injury. At presentation, 35% of closed SCFs and 23% of open SCFs presented with abnormal neurovascular status. There was a higher prevalence of diminished/absent pulses or distal limb ischemia in patients with open injuries (27%) compared with closed fractures (18%). Conversely, severely displaced closed fractures were more commonly associated with nerve injury/palsy at presentation (35%) than those with open fractures (23%). Spontaneous nerve recovery was seen in 87% within 3 to 6 months. Postoperative loss of reduction and malunion were more common in the closed fracture group. However, 84% of patients achieved good-to-excellent results by Flynn criteria, with no appreciable difference based upon open versus closed fractures. With timely wound and fracture treatment, the clinical and radiographic results of children treated for open SCFs is similar to

Effectiveness of Dual-Maneuver Using K-Wire and Dingman Elevator for the Reduction of Unstable Zygomatic Arch Fracture.

Science.gov (United States)

Yoon, Hyungwoo; Kim, Jiye; Chung, Seum; Chung, Yoon-Kyu

2014-08-01

The zygoma is the most prominent portion of the face. Almost all simple zygomatic arch fractures are treated in a closed fashion with a Dingman elevator. However, the open approach should be considered for unstable zygomatic arch fractures. The coronal approach for a zygomatic arch fracture has complications. In this study, we introduce our method to reduce a special type of unstable zygomatic fracture. We retrospectively reviewed zygomatic arch view and facial bone computed tomography scans of 424 patients who visited the Wonju Severance Christian Hospital from 2007 to 2010 with zygomaticomaxillary fractures, among whom 15 patients met the inclusion criteria. We used a Dingman elevator and K-wire simultaneously to manage this type of zygomatic arch fracture. Simple medial rotation force usually collapses the posterior fractured segment, and the fracture becomes unstable. Thus, the posterior fracture segment must be concurrently elevated with a Dingman elevator through Keen's approach with rotation force applied through the K-wire. All fractures were reduced without any instability using this method. We were able to reduce unstable and difficult zygomatic arch fractures without an open incision or any external fixation device.

Associations of early premenopausal fractures with subsequent fractures vary by sites and mechanisms of fractures.

Science.gov (United States)

Honkanen, R; Tuppurainen, M; Kroger, H; Alhava, E; Puntila, E

1997-04-01

In a retrospective population-based study we assessed whether and how self-reported former fractures sustained at the ages of 20-34 are associated with subsequent fractures sustained at the ages of 35-57. The 12,162 women who responded to fracture questions of the baseline postal enquiry (in 1989) of the Kuopio Osteoporosis Study, Finland formed the study population. They reported 589 former and 2092 subsequent fractures. The hazard ratio (HR), with 95% confidence interval (CI), of a subsequent fracture was 1.9 (1.6-2.3) in women with the history of a former fracture compared with women without such a history. A former low-energy wrist fracture was related to subsequent low-energy wrist [HR = 3.7 (2.0-6.8)] and high-energy nonwrist [HR = 2.4 (1.3-4.4)] fractures, whereas former high-energy nonwrist fractures were related only to subsequent high-energy nonwrist [HR = 2.8 (1.9-4.1)] but not to low-energy wrist [HR = 0.7 (0.3-1.8)] fractures. The analysis of bone mineral density (BMD) data of a subsample of premenopausal women who underwent dual x-ray absorptiometry (DXA) during 1989-91 revealed that those with a wrist fracture due to a fall on the same level at the age of 20-34 recorded 6.5% lower spinal (P = 0.140) and 10.5% lower femoral (P = 0.026) BMD than nonfractured women, whereas the corresponding differences for women with a former nonwrist fracture due to high-energy trauma were -1.8% (P = 0.721) and -2.4% (P = 0. 616), respectively. Our results suggest that an early premenopausal, low-energy wrist fracture is an indicator of low peak BMD which predisposes to subsequent fractures in general, whereas early high-energy fractures are mainly indicators of other and more specific extraskeletal factors which mainly predispose to same types of subsequent fractures only.

A study on management of extracapsular trochanteric fractures by proximal femoral nail

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K Ramaprathap Reddy

2016-01-01

Full Text Available Background: Trochanteric fractures of femur like intertrochanteric and subtrochanteric fractures are a leading cause of hospital admissions in elderly people. Conservative methods of treatment results in malunion with shortening and limitation of hip movement as well as complications of prolonged immobilizations such as bed sores, deep vein thrombosis, and respiratory infections. This study is done to analyze the surgical management of trochanteric fractures of the femur using a proximal femoral nail (PFN. Methodology: This is a prospective study of 40 cases of trochanteric and subtrochanteric fractures admitted to Government General Hospital, Vijayawada, Andhra Pradesh. Cases were taken according to inclusion and exclusion criteria, i.e., patients with trochanteric fractures femur above the age of 20 years. Medically unsuitable, open fractures and patients not willing for surgery were excluded from the study. Results: Forty percentage of cases were admitted due to slip and fall and with a slight predominance of the right side. Out of 40 cases, 26 were trochanteric, and 14 were subtrochanteric. In trochanteric class, 37.5% were body and griffin Type 2, in subtrochanteric class 12.5% were sinsheimer Type 3a and 10% were 2b. Out of 30 remaining cases, 25 were trochanteric, and 05 were subtrochanteric. Good to excellent results are seen in 100% cases of trochanteric fractures and 90% cases in subtrochanteric fractures. Conclusion: From this sample study, we consider that PFN is an excellent implant for the treatment of pertrochanteric fractures. The terms of successful outcome include a good understanding of fracture biomechanics, proper patient selection, good preoperative planning, accurate instrumentation, good image intensifier, and exactly performed osteosynthesis.

Fracture Analysis of the FAA/NASA Wide Stiffened Panels

Science.gov (United States)

Seshadri, B. R.; Newman, J. C., Jr.; Dawicke, D. S.; Young, R. D.

1999-01-01

This paper presents the fracture analyses conducted on the FAA/NASA stiffened and unstiffened panels using the STAGS (STructural Analysis of General Shells) code with the critical crack-tip-opening angle (CTOA) fracture criterion. The STAGS code with the "plane-strain" core option was used in all analyses. Previous analyses of wide, flat panels have shown that the high-constraint conditions around a crack front, like plane strain, has to be modeled in order for the critical CTOA fracture criterion to predict wide panel failures from small laboratory tests. In the present study, the critical CTOA value was determined from a wide (unstiffened) panel with anti-buckling guides. The plane-strain core size was estimated from previous fracture analyses and was equal to about the sheet thickness. Rivet flexibility and stiffener failure was based on methods and criteria, like that currently used in industry. STAGS and the CTOA criterion were used to predict load-against-crack extension for the wide panels with a single crack and multiple-site damage cracking at many adjacent rivet holes. Analyses were able to predict stable crack growth and residual strength within a few percent (5%) of stiffened panel tests results but over predicted the buckling failure load on an unstiffened panel with a single crack by 10%.

Free fibular strut graft in neglected femoral neck fractures in adult

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Azam Md Quamar

2009-01-01

Full Text Available Background: Neglected femoral neck fracture in adults still poses a formidable challenge. Existing treatment options varies from osteotomy (with or without graft to osteosynthesis using various implants and grafting techniques (muscle pedicle, vascularized, and nonvascularized fibula. The aim of this study was to assess outcome of nonvascularized fibular strut graft and cancellous screw fixation in neglected femoral neck fractures in the younger age group. Materials and Methods: Medical records of 32 patients of neglected femoral neck fracture, in the age group of 22-45 years (mean 37.8 years, operated between May 1994 to December 2001, were retrospectively reviewed. After the application of inclusion and exclusion criteria, 28 patients having three years minimum follow-up (mean 4.6 years were included. Delay between injury and operation varied from four weeks to 42 weeks (mean 16.4 weeks. Closed reduction was achieved in 17 patients; open reduction through Watson-Jones anterolateral approach was performed in the remaining 15 patients in whom closed reduction failed. The fracture was transfixed with three parallel guide wires. Appropriate sized cannulated lag screw (7 mm was then inserted in two of the wires. Selection of the third guide wire for fibula depended on the space available in both anteroposterior and lateral view. Results: Satisfactory bony union was obtained in 25 patients, of whom in four cases, the union occurred in 10-20° (mean 15° of varus. Nonunion occurred in three patients (9.37%, and aseptic necrosis occurred in another six patients (18.75%. Of the 25 patients where union was achieved, five patients showed excellent results; 14 good and six had poor functional result, as evaluated using modified Anglen criteria. Conclusion: Nonvascularized fibular strut graft along with cancellous screws provides a dependable and technically less-demanding alternative procedure for neglected femoral neck fractures in young adults. Fibula

Consequences of quality of reduction on osteosynthesis complications and quality of life in elderly patients with subtrochanteric fracture.

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Codesido-Vilar, P; Mejía-Casado, A; Riego-Fernández, J; Rodriguez-Casas, N; García-Cabanas, S; Rivas-Felice, J; García-Quevedo, L

2018-05-18

To compare results in terms of orthopaedic complications and quality of life in elderly patients with subtrochanteric fracture treated with intramedullary nailing according to fracture reduction status. A prospective cohort study including 90 elderly patients with subtrochanteric fractures of the femur treated with a cephalomedullary nail, with a minimum 1-year follow up. The inclusion criteria were: aged 60 years or older, without severe cognitive dysfunction and independent ambulatory capability before the fracture. We defined 3different groups in relation to fracture reduction status: good, acceptable and poor, according to modified criteria from Baumgartner et al. We compared clinical and surgical characteristics and healthy quality of life, social function and mobility according to the EQ-5D, Jensen Index and Mobility Score of Parker and Palmer questionnaires. We found differences in time to union, better in the good reduction group (P=.002); need for open reduction, more frequent in the good reduction group (P<.001), and in postoperative complications, more frequent in the poor reduction group (P=.001). We found no significant differences between the 3groups regarding scores in quality of life, social function and mobility. Reduction in subtrochanteric fractures in older people is key to obtaining better clinic and surgical results, improving time to union and decreasing surgical complications. Exposure of the focus fracture seems to be a safe manoeuvre. Quality of life had substantially deteriorated n these patients, but a there was a tendency, although not statistically significant, for it to improve in patients after good surgical reduction. Copyright © 2018 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

The effect of canal fill on paediatric femur fractures treated with titanium elastic nails.

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Nielsen, E; Bonsu, N; Andras, L M; Goldstein, R Y

2018-02-01

Traditional teaching for fixation of paediatric femur fractures recommends 80% nail diameter/medullary canal diameter ratio (ND/MCD) for successful maintenance of reduction. Prior studies have investigated this with stainless steel Enders nails. Our aim was to assess the impact of ND/MCD on maintenance of reduction and malunion rates in paediatric femur fractures treated with flexible intramedullary nails (FINs). Retrospective data was collected on all paediatric patients treated with FINs for diaphyseal femur fractures at a single tertiary care institution over a ten-year period. Patients with co-morbidities affecting bone quality were excluded. Patients were subdivided into groups based on ND/MCD. A total of 66 patients met inclusion criteria. Mean ND/MCD was 76.3% (32.9% to 98.8%, SD 14.3). In all, 50% (n = 33/66) of patients had > 80% ND/MCD, and only 13.6% (n = 9/66) of patients had less than 60% ND/MCD. When controlling for fracture stability, ND/MCD had no correlation with mean shortening (p = 0.07) There was no correlation between ND/MCD and angulation in the sagittal (p = 0.96) or coronal plane (p = 0.20). Three patients fit malunion criteria. ND/MCD for these patients were 40%, 67% and 79%. There was no correlation between ND/MCD and shortening or malangulation. The majority of patients in this series with less than 80% fill with FIN healed within acceptable parameters. III.

A compilation of minutes for the Stripa task force on fracture flow modelling

International Nuclear Information System (INIS)

Hodgkinson, D.

1992-01-01

This report is a compilation of minutes from the nine meetings of the Stripa task force on fracture flow modelling, held at various locations around the world from February 1988 to December 1991. The task force was set up as a peer review group with the specific objectives of 1. recommending criteria for the verification and validation of fracture flow models, 2. facilitating the dissemination of information to countries participating in the Stripa project, and 3. coordinating the work of the three modelling groups form AEA Harwell, Golder Associates and Lawrence Berkeley Laboratory. The report provides a detailed technical commentary of the interplay between the development and application of mathematical models, and the design, execution and interpretation of experiment, within a structured project management framework. In particular, the task force has pioneered the definition and implementation of a validation process and associated criteria based on the analysis of a wide range of experimental data. (au)

Ballistic fractures: indirect fracture to bone.

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Dougherty, Paul J; Sherman, Don; Dau, Nathan; Bir, Cynthia

2011-11-01

Two mechanisms of injury, the temporary cavity and the sonic wave, have been proposed to produce indirect fractures as a projectile passes nearby in tissue. The purpose of this study is to evaluate the temporal relationship of pressure waves using strain gauge technology and high-speed video to elucidate whether the sonic wave, the temporary cavity, or both are responsible for the formation of indirect fractures. Twenty-eight fresh frozen cadaveric diaphyseal tibia (2) and femurs (26) were implanted into ordnance gelatin blocks. Shots were fired using 9- and 5.56-mm bullets traversing through the gelatin only, passing close to the edge of the bone, but not touching, to produce an indirect fracture. High-speed video of the impact event was collected at 20,000 frames/s. Acquisition of the strain data were synchronized with the video at 20,000 Hz. The exact time of fracture was determined by analyzing and comparing the strain gauge output and video. Twenty-eight shots were fired, 2 with 9-mm bullets and 26 with 5.56-mm bullets. Eight indirect fractures that occurred were of a simple (oblique or wedge) pattern. Comparison of the average distance of the projectile from the bone was 9.68 mm (range, 3-20 mm) for fractured specimens and 15.15 mm (range, 7-28 mm) for nonfractured specimens (Student's t test, p = 0.036). In this study, indirect fractures were produced after passage of the projectile. Thus, the temporary cavity, not the sonic wave, was responsible for the indirect fractures.

Alendronate treatment alters bone tissues at multiple structural levels in healthy canine cortical bone.

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Acevedo, Claire; Bale, Hrishikesh; Gludovatz, Bernd; Wat, Amy; Tang, Simon Y; Wang, Mingyue; Busse, Björn; Zimmermann, Elizabeth A; Schaible, Eric; Allen, Matthew R; Burr, David B; Ritchie, Robert O

2015-12-01

Bisphosphonates are widely used to treat osteoporosis, but have been associated with atypical femoral fractures (AFFs) in the long term, which raises a critical health problem for the aging population. Several clinical studies have suggested that the occurrence of AFFs may be related to the bisphosphonate-induced changes of bone turnover, but large discrepancies in the results of these studies indicate that the salient mechanisms responsible for any loss in fracture resistance are still unclear. Here the role of bisphosphonates is examined in terms of the potential deterioration in fracture resistance resulting from both intrinsic (plasticity) and extrinsic (shielding) toughening mechanisms, which operate over a wide range of length-scales. Specifically, we compare the mechanical properties of two groups of humeri from healthy beagles, one control group comprising eight females (oral doses of saline vehicle, 1 mL/kg/day, 3 years) and one treated group comprising nine females (oral doses of alendronate used to treat osteoporosis, 0.2mg/kg/day, 3 years). Our data demonstrate treatment-specific reorganization of bone tissue identified at multiple length-scales mainly through advanced synchrotron x-ray experiments. We confirm that bisphosphonate treatments can increase non-enzymatic collagen cross-linking at molecular scales, which critically restricts plasticity associated with fibrillar sliding, and hence intrinsic toughening, at nanoscales. We also observe changes in the intracortical architecture of treated bone at microscales, with partial filling of the Haversian canals and reduction of osteon number. We hypothesize that the reduced plasticity associated with BP treatments may induce an increase in microcrack accumulation and growth under cyclic daily loadings, and potentially increase the susceptibility of cortical bone to atypical (fatigue-like) fractures. Published by Elsevier Inc.

Differential diagnosis of benign and malignant vertebral compression fractures with MR imaging

International Nuclear Information System (INIS)

Staebler, A.; Krimmel, K.; Seiderer, M.; Gaertner, C.; Fritsch, S.; Raum, W.

1992-01-01

42 patients with known malignancy and vertebral compressions underwent MRI. Sagittal T 1 -weighted spin-echo images pre and post Gd-DTPA, out of phase long TR gradient-echo images (GE) and short T 1 inversion recovery images (STIR) were obtained at 1.0 T. In 39 of 42 cases a correct differentiation between osteoporotic and tumorous vertebral compression fractures was possible by quantification and correlation of SE and GE signal intensities. Gd-DTPA did not improve differential diagnosis, since both tumour infiltration and bone marrow oedema in acute compression fracture showed comparable enhancement. STIR-sequences were most sensitive for pathology but unspecific due to a comparable amount of water in tumour tissue and bone marrow oedema. Susceptibility-induced signal reduction in GE images and morphologic criteria proved to be most reliable for differentiation of benign and tumour-related fractures. (orig./GDG) [de

Nutrient and food intakes in early life and risk of childhood fractures

DEFF Research Database (Denmark)

Händel, Mina N; Heitmann, Berit L; Abrahamsen, Bo

2015-01-01

BACKGROUND: The identification of detrimental dietary patterns early in life may contribute to reducing the high incidence of fracture among healthy children. However, information based on a systematic review of the effect of various dietary foods and nutrients on fracture risk is lacking......, Web of Science, and Scopus databases and by hand searching references by first author based on predefined inclusion criteria. A meta-analysis was carried out for case-control studies that examined differences in mean calcium intake in the case compared with the control group. Random-effects analysis...... of a systematic review of studies that were judged to be of high or medium quality, there is an indication that some nutritional factors seem to be associated with an increased fracture risk among children. The results may be inflated by selection bias, bias in diet reporting, or residual confounding. More high...

Screw elastic intramedullary nail for the management of adult forearm fractures

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Wasudeo Gadegone

2012-01-01

Full Text Available Background: The failure of the conventional nailing of both forearm bones or isolated fractures of radius and ulna pose a potential problem of nail migration and rotational instability, despite the best reduction. The purpose of this paper is to evaluate the results of screw elastic intramedullary nail for the treatment of adult diaphyseal fractures of both forearm bones, which effectively addresses the problems associated with the conventional nailing systems for the forearm fractures. Materials and Methods: Seventy-six adults with forearm fractures (radius and ulna or isolated fracture of the single bone were retrospectively evaluated. Fifty males and 26 females with the mean age of 38 years (range, 18-70 years underwent closed reduction and screw intramedullary nail fixation. Ten patients required limited open reduction. The fractures were classified according to the AO/OTA system. The average followup was 12 months (range, 6 to 18 months. Results: The mean surgical time was 45 minutes (35 to 65 minutes. The meantime to union was 14 weeks (10-21 weeks. The results were graded as excellent in 50, good in 18 patients, and acceptable in eight patients, using the criteria of Grace and Eversman. We had superficial infection in three cases, one case of delayed infection, painful bursa in two cases, delayed union in two cases, malunion with dislocation of the DRUJ in two cases, injury to the extensor tendon of the thumb in one case, and one case of incomplete radioulnar synostosis. Conclusion: Closed reduction and internal fixation of forearm fractures by screw intramedullary nails reestablishes the near normal relationship of the fractured fragments. Screw intramedullary nail effectively controls both rotatory forces and the migration of the nail. It produces excellent clinical results in isolated fractures of either bones, as well as both bones of the forearm in adults.

Late presentation of fractures of the lateral condyle of the humerus in children

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Shyam K Saraf

2011-01-01

Full Text Available Background: The current controversy regarding the management of fractures of the lateral condyle of the humerus presenting between 3 to 12 weeks prompted us to evaluate our results of open reduction and internal fixation of such fractures. Patients and Methods: Twenty-one patients operated between March 1995 and February 2001 qualified for this study. Five patients presented between 3-4 weeks, nine between 5-8 weeks and seven between 9-12 weeks post injury. Ten fractures were classified as stage II and eleven as stage III (Jacob et al. criteria. The mean age was 8 years (range: 4-14 years. All patients underwent surgery (open reduction and internal fixation with K-wires/screw, with or without bone grafting. The results were assessed by the modified criteria of Agarwal et al. after an average follow-up of 2.3 years. Results: Excellent to good results were observed in all the five patients presenting at 3-4 weeks post injury. In the patients presenting at 5-8 weeks, the results were excellent in one, good in four, fair in three, and poor in one patient. The fracture united in all cases; however, malunion was observed in four patients. The fractures that were operated at 9-12 weeks showed good results in one case, fair result in three cases, and poor result in three cases. Avascular necrosis of the lateral condyle in one patient, premature fusion in two patients, pin tract infection in three patients, and gross restriction of elbow movements in three patients were the major complications in this group. Accurate reduction was difficult as a result of new bone formation and remodeling at the fracture surfaces. Multiple incisions over the common extensor aponeurosis and bone graft supplementation were helpful for achieving acceptable reduction. Conclusion: Open reduction and internal fixation is recommended in all cases of displaced fractures of the lateral condyle of the humerus presenting at up to 12 weeks post injury. However, the results become

Distinguishing stress fractures from pathologic fractures: a multimodality approach

International Nuclear Information System (INIS)

Fayad, Laura M.; Kamel, Ihab R.; Kawamoto, Satomi; Bluemke, David A.; Fishman, Elliot K.; Frassica, Frank J.

2005-01-01

Whereas stress fractures occur in normal or metabolically weakened bones, pathologic fractures occur at the site of a bone tumor. Unfortunately, stress fractures may share imaging features with pathologic fractures on plain radiography, and therefore other modalities are commonly utilized to distinguish these entities. Additional cross-sectional imaging with CT or MRI as well as scintigraphy and PET scanning is often performed for further evaluation. For the detailed assessment of a fracture site, CT offers a high-resolution view of the bone cortex and periosteum which aids the diagnosis of a pathologic fracture. The character of underlying bone marrow patterns of destruction can also be ascertained along with evidence of a soft tissue mass. MRI, however, is a more sensitive technique for the detection of underlying bone marrow lesions at a fracture site. In addition, the surrounding soft tissues, including possible involvement of adjacent muscle, can be well evaluated with MRI. While bone scintigraphy and FDG-PET are not specific, they offer a whole-body screen for metastases in the case of a suspected malignant pathologic fracture. In this review, we present select examples of fractures that underscore imaging features that help distinguish stress fractures from pathologic fractures, since accurate differentiation of these entities is paramount. (orig.)

Double segmental tibial fractures - an unusual fracture pattern

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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

Mechanics of the Delayed Fracture of Viscoelastic Bodies with Cracks: Theory and Experiment (Review)

Science.gov (United States)

Kaminsky, A. A.

2014-09-01

Theoretical and experimental studies on the deformation and delayed fracture of viscoelastic bodies due to slow subcritical crack growth are reviewed. The focus of this review is on studies of subcritical growth of cracks with well-developed fracture process zones, the conditions that lead to their critical development, and all stages of slow crack growth from initiation to the onset of catastrophic growth. Models, criteria, and methods used to study the delayed fracture of viscoelastic bodies with through and internal cracks are analyzed. Experimental studies of the fracture process zones in polymers using physical and mechanical methods as well as theoretical studies of these zones using fracture mesomechanics models that take into account the structural and rheological features of polymers are reviewed. Particular attention is given to crack growth in anisotropic media, the effect of the aging of viscoelastic materials on their delayed fracture, safe external loads that do not cause cracks to propagate, the mechanism of multiple-flaw fracture of viscoelastic bodies with several cracks and, especially, processes causing cracks to coalesce into a main crack, which may result in a break of the body. Methods and results of solving two- and three-dimensional problems of the mechanics of delayed fracture of aging and non-aging viscoelastic bodies with cracks under constant and variable external loads, wedging, and biaxial loads are given

Linked versus unlinked hospital discharge data on hip fractures for estimating incidence and comorbidity profiles.

Science.gov (United States)

Vu, Trang; Day, Lesley; Finch, Caroline F

2012-08-01

Studies comparing internally linked (person-identifying) and unlinked (episodes of care) hospital discharge data (HDD) on hip fractures have mainly focused on incidence overestimation by unlinked HDD, but little is known about the impact of overestimation on patient profiles such as comorbidity estimates. In view of the continuing use of unlinked HDD in hip fracture research and the desire to apply research results to hip fracture prevention, we concurrently assessed the accuracy of both incidence and comorbidity estimates derived from unlinked HDD compared to those estimated from internally linked HDD. We analysed unlinked and internally linked HDD between 01 July 2005 and 30 June 2008, inclusive, from Victoria, Australia to estimate the incidence of hospital admission for fall-related hip fracture in community-dwelling older people aged 65+ years and determine the prevalence of comorbidity in patients. Community-dwelling status was defined as living in private residence, supported residential facilities or special accommodation but not in nursing homes. We defined internally linked HDD as the reference standard and calculated measures of accuracy of fall-related hip fracture incidence by unlinked HDD using standard definitions. The extent to which comorbidity prevalence estimates by unlinked HDD differed from those by the reference standard was assessed in absolute terms. The sensitivity and specificity of a standard approach for estimating fall-related hip fracture incidence using unlinked HDD (i.e. omitting records of in-hospital deaths, inter-hospital transfers and readmissions within 30 days of discharge) were 94.4% and 97.5%, respectively. The standard approach and its variants underestimated the prevalence of some comorbidities and altered their ranking. The use of more stringent selection criteria led to major improvements in all measures of accuracy as well as overall and specific comorbidity estimates. This study strongly supports the use of linked

Recording length criteria as applied in ultrasonic testing

International Nuclear Information System (INIS)

Fischer, E.; Kroening, M.; Schober, H.; Fischdick, H.

1983-01-01

An appreciable method used to assess the quality and integrity of safety-related components in light water reactors is the ultrasonic examination, in which case great importance is attributed to the criteria pertaining to recording length and permissible defect size. The development of the recording length criteria as applied when employing this method of examination is portrayed, the latter being based on the criteria which have proven themselves throughout long years of practice in the examination of conventional components. When taking these criteria into account the application of conventional ultrasonic techniques often leads to problems in the case of thick-walled components the reason being that indications are overrated. Taking the design of reactor components as the basic point of consideration, modified criteria are derived particularly when the size of discontinuities calculated by fracture mechanics analyses is taken into account. The introduction of new ultrasonic examination techniques such as, for example, focussed probes revealed that a considerably more realistic assessment is possible and consequently results in a reduction of unnecessary repairs. A comparison of the size of indications determined using conventional and analytical technqiues renders possible the anchoring of an intermediate stage in the evaluation of indications which is encompassed in the consideration of the bundle divergence. Thus a new concept is realized for the evaluation of ultrasonic indications detected in reactor components, which in the meantime has found its way into the associated regulatory guides. (orig.)

Ankle fracture spur sign is pathognomonic for a variant ankle fracture.

Science.gov (United States)

Hinds, Richard M; Garner, Matthew R; Lazaro, Lionel E; Warner, Stephen J; Loftus, Michael L; Birnbaum, Jacqueline F; Burket, Jayme C; Lorich, Dean G

2015-02-01

The hyperplantarflexion variant ankle fracture is composed of a posterior tibial lip fracture with posterolateral and posteromedial fracture fragments separated by a vertical fracture line. This infrequently reported injury pattern often includes an associated "spur sign" or double cortical density at the inferomedial tibial metaphysis. The objective of this study was to quantitatively establish the association of the ankle fracture spur sign with the hyperplantarflexion variant ankle fracture. Our clinical database of operative ankle fractures was retrospectively reviewed for the incidence of hyperplantarflexion variant and nonvariant ankle fractures as determined by assessment of injury radiographs, preoperative advanced imaging, and intraoperative observation. Injury radiographs were then evaluated for the presence of the spur sign, and association between the spur sign and variant fractures was analyzed. The incidence of the hyperplantarflexion variant fracture among all ankle fractures was 6.7% (43/640). The spur sign was present in 79% (34/43) of variant fractures and absent in all nonvariant fractures, conferring a specificity of 100% in identifying variant fractures. Positive predictive value and negative predictive value were 100% and 99%, respectively. The ankle fracture spur sign was pathognomonic for the hyperplantarflexion variant ankle fracture. It is important to identify variant fractures preoperatively as patient positioning, operative approach, and fixation construct of variant fractures often differ from those employed for osteosynthesis of nonvariant fractures. Identification of the spur sign should prompt acquisition of advanced imaging to formulate an appropriate operative plan to address the variant fracture pattern. Level III, retrospective comparative study. © The Author(s) 2014.

Association of Ipsilateral Rib Fractures With Displacement of Midshaft Clavicle Fractures.

Science.gov (United States)

Stahl, Daniel; Ellington, Matthew; Brennan, Kindyle; Brennan, Michael

2017-04-01

To determine whether the presence of ipsilateral rib fractures affects the rate of a clavicle fracture being unstable (>100% displacement). A retrospective review from 2002-2013 performed at a single level 1 trauma center evaluated 243 midshaft clavicle fractures. Single Level 1 trauma center. These fractures were subdivided into those with ipsilateral rib fractures (CIR; n = 149) and those without ipsilateral rib fractures (CnIR; n = 94). The amount of displacement was measured on the initial injury radiograph and subsequent follow-up radiographs. Fractures were classified into either 100% displacement, based on anteroposterior radiographs. Ipsilateral rib fractures were recorded based on which number rib was fractured and the total number of fractured ribs. One hundred sixteen (78%) of the CIR group and 51 (54%) of the CnIR group were found to have >100% displacement at follow-up (P = 0.0047). Seventy-two percent of the CIR group demonstrated progression from 100% displacement of the fracture compared with only 54% of the CnIR group (P fracture to >100% was 4.08 (P = 0.000194) when ribs 1-4 were fractured and not significant for rib fractures 5-8 or 9-12. The presence of concomitant ipsilateral rib fractures significantly increases the rate of midshaft clavicle fractures being >100% displaced. In addition, a fracture involving the upper one-third of the ribs significantly increases the rate of the clavicle fracture being >100% displaced on early follow-up. Clavicle fractures with associated ipsilateral rib fractures tend to demonstrate an increased amount of displacement on follow-up radiographs compared with those without ipsilateral rib fractures. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Influence of Aging Conditions on Fatigue Fracture Behaviour of 6063 Aluminum Alloy

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Rafiq Ahmed Siddiqui

2001-12-01

Full Text Available Aluminum - Magnesium - Silicon (Al-Mg-Si 6063 alloy was heat-treated using under aged, peak aged and overage temperatures. The numbers of cycles required to cause the fatigue fracture, at constant stress, was considered as criteria for the fatigue resistance. Moreover, the fractured surface of the alloy at different aging conditions was evaluated by optical microscopy and the Scanning Electron Microscopy (SEM. The SEM micrographs confirmed the cleavage surfaces with well-defined fatigue striations. It has been observed that the various aging time and temperature of the 6063 Al-alloy, produces different modes of fractures. The most suitable age hardening time and temperature was found to be between 4 to 5 hours and to occur at 460 K. The increase in fatigue fracture property of the alloy due to aging could be attributed to a vacancy assisted diffusion mechanism or due to pinning of dislocations movement by the precipitates produced during aging. However, the decrease in the fatigue resistance, for the over aged alloys, might be due to the coalescence of precipitates into larger grains.

Short- and long-term results following standing fracture repair in 34 horses.

Science.gov (United States)

Payne, R J; Compston, P C

2012-11-01

Standing fracture repair in the horse is a recently described surgical procedure and currently there are few follow-up data. This case series contains 2 novel aspects in the standing horse: repair of incomplete sagittal fractures of the proximal phalanx and medial condylar repair from a lateral aspect. To describe outcome in a case series of horses that had lower limb fractures repaired under standing sedation at Rossdales Equine Hospital. Case records for all horses that had a fracture surgically repaired, by one surgeon at Rossdales Equine Hospital, under standing sedation and local anaesthesia up until June 2011, were retrieved. Hospital records, owner/trainer telephone questionnaire and the Racing Post website were used to evaluate follow-up. Thirty-four horses satisfied the inclusion criteria. Fracture sites included the proximal phalanx (incomplete sagittal fracture, n = 14); the third metacarpal bone (lateral condyle, n = 12, and medial condyle, n = 7); and the third metatarsal bone (lateral condyle, n = 1). One horse required euthanasia due to caecal rupture 10 days post operatively. Twenty horses (66.7% of those with available follow-up) have returned to racing. Where available, mean time from operation to return to racing was 226 days (range 143-433 days). Standing fracture repair produced similar results to fracture repair under general anaesthesia in terms of both the number of horses that returned to racing and the time between surgery and race. Repair of lower limb fracture in the horse under standing sedation is a procedure that has the potential for tangible benefits, including avoidance of the inherent risks of general anaesthesia. The preliminary findings in this series of horses are encouraging and informative when discussing options available prior to fracture repair. © 2012 EVJ Ltd.

Using decision analysis to assess comparative clinical efficacy of surgical treatment of unstable ankle fractures.

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Michelson, James D

2013-11-01

The development of a robust treatment algorithm for ankle fractures based on well-established stability criteria has been shown to be prognostic with respect to treatment and outcomes. In parallel with the development of improved understanding of the biomechanical rationale of ankle fracture treatment has been an increased emphasis on assessing the effectiveness of medical and surgical interventions. The purpose of this study was to investigate the use of using decision analysis in the assessment of the cost effectiveness of operative treatment of ankle fractures based on the existing clinical data in the literature. Using the data obtained from a previous structured review of the ankle fracture literature, decision analysis trees were constructed using standard software. The decision nodes for the trees were based on ankle fracture stability criteria previously published. The outcomes were assessed by calculated Quality-Adjusted Life Years (QALYs) assigned to achieving normal ankle function, developing posttraumatic arthritis, or sustaining a postoperative infection. Sensitivity analysis was undertaken by varying the patient's age, incidence of arthritis, and incidence or infection. Decision analysis trees captured the essential aspects of clinical decision making in ankle fracture treatment in a clinically useful manner. In general, stable fractures yielded better outcomes with nonoperative treatment, whereas unstable fractures had better outcomes with surgery. These were consistent results over a wide range of postoperative infection rates. Varying the age of the patient did not qualitatively change the results. Between the ages of 30 and 80 years, surgery yielded higher expected QALYs than nonoperative care for unstable fractures, and generated lower QALYs than nonoperative care for stable fractures. Using local cost estimates for operative and nonoperative treatment, the incremental cost of surgery for unstable fractures was less than $40,000 per QALY (the

The value of arthroscopy in the treatment of complex ankle fractures - a protocol of a randomised controlled trial.

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Braunstein, Mareen; Baumbach, Sebastian F; Regauer, Markus; Böcker, Wolfgang; Polzer, Hans

2016-05-12

An anatomical reconstruction of the ankle congruity is the important prerequisite in the operative treatment of acute ankle fractures. Despite anatomic restoration patients regularly suffer from residual symptoms after these fractures. There is growing evidence, that a poor outcome is related to the concomitant traumatic intra-articular pathology. By supplementary ankle arthroscopy anatomic reduction can be confirmed and associated intra-articular injuries can be treated. Nevertheless, the vast majority of complex ankle fractures are managed by open reduction and internal fixation (ORIF) only. Up to now, the effectiveness of arthroscopically assisted fracture treatment (AORIF) has not been conclusively determined. Therefore, a prospective randomised study is needed to sufficiently evaluate the effect of AORIF compared to ORIF in complex ankle fractures. We perform a randomised controlled trial at Munich University Clinic enrolling patients (18-65 years) with an acute ankle fracture (AO 44 A2, A3, B2, B3, C1 - C3 according to AO classification system). Patients meeting the inclusion criteria are randomised to either intervention group (AORIF, n = 37) or comparison group (ORIF, n = 37). Exclusion criteria are fractures classified as AO type 44 A1 or B1, pilon or plafond-variant injury or open fractures. Primary outcome is the AOFAS Score (American Orthopaedic Foot and Ankle Society). Secondary outcome parameter are JSSF Score (Japanese Society of Surgery of the Foot), Olerud and Molander Score, Karlsson Score, Tegner Activity Scale, SF-12, radiographic analysis, arthroscopic findings of intra-articular lesions, functional assessments, time to return to work/sports and complications. This study protocol is accordant to the SPIRIT 2013 recommendation. Statistical analysis will be performed using SPSS 22.0 (IBM). The subjective and functional outcome of complex ankle fractures is regularly unsatisfying. As these injuries are very common it is essential to

Arthroscopy-Assisted Surgery for Acute Ankle Fractures: A Systematic Review.

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Chen, Xing-Zuo; Chen, Ying; Liu, Cheng-Gang; Yang, Huan; Xu, Xiao-Dong; Lin, Peng

2015-11-01

To summarize the clinical findings of adult patients undergoing arthroscopy-assisted open reduction-internal fixation for acute ankle fractures. A systematic electronic search of the PubMed databases was performed for all published literature on December 8, 2014. All English-language clinical studies on acute ankle fractures treated with arthroscopy-assisted open reduction-internal fixation were eligible for inclusion. Basic information related to the surgical procedure was collected. The search criteria initially identified 187 articles, and 10 studies were included in this systematic review. There were 2 prospective, randomized studies; 2 prognostic studies; and 6 case-series studies. There were a total of 861 patients included in this systematic review. Danis-Weber type B fractures (335 of 483 patients) and supination-external rotation fractures (187 of 366 patients) were the most common types of all the ankle fractures. Concomitant injuries were common: 63.3% of patients had chondral lesions, 60.9% had deltoid ligament injuries, and 77.9% had tibiofibular syndesmosis injuries. Lavage and debridement of the ankle joint were performed by almost all the surgeons. Chondral lesions were treated with shaving, excision, or microfracture. The mean American Orthopaedic Foot & Ankle Society hindfoot score was 91.7. Only mild complications were reported. Acute ankle fractures are commonly concomitant with multiple soft-tissue injuries in which arthroscopy may serve as a method for accurate diagnosis and appropriate treatment. Level IV, systematic review of Level I, II, III, and IV studies. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Management of Hangman's Fractures: A Systematic Review.

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Murphy, Hamadi; Schroeder, Gregory D; Shi, Weilong J; Kepler, Christopher K; Kurd, Mark F; Fleischman, Andrew N; Kandziora, Frank; Chapman, Jens R; Benneker, Lorin M; Vaccaro, Alexander R

2017-09-01

Traumatic spondylolisthesis of the axis, is a common cervical spine fracture; however, to date there is limited data available to guide the treatment of these injuries. The purpose of this review is to provide an evidence-based analysis of the literature and clinical outcomes associated with the surgical and nonsurgical management of hangman's fractures. A systematic literature search was conducted using PubMed (MEDLINE) and Scopus (EMBASE, MEDLINE, COMPENDEX) for all articles describing the treatment of hangman's fractures in 2 or more patients. Risk of nonunion, mortality, complications, and treatment failure (defined as the need for surgery in the nonsurgically managed patients and the need for revision surgery for any reason in the surgically managed patients) was compared for operative and nonoperative treatment methods using a generalized linear mixed model and odds ratio analysis. Overall, 25 studies met the inclusion criteria and were included in our quantitative analysis. Bony union was the principal outcome measure used to assess successful treatment. All studies included documented fracture union and were included in statistical analyses. The overall union rate for 131 fractures treated nonsurgically was 94.14% [95% confidence interval (CI), 76.15-98.78]. The overall union rate for 417 fractures treated surgically was 99.35% (95% CI, 96.81-99.87). Chance of nonunion was lower in those patients treated surgically (odds ratio, 0.12; 95% CI, 0.02-0.71). There was not a significant difference in mortality between patients treated surgically (0.16%; 95% CI, 0.01%-2.89%) and nonsurgically (1.04%; 95% CI, 0.08%-11.4%) (odds ratio, 0.15; 95% CI, 0.01-2.11). Treatment failure was less likely in the surgical treatment group (0.12%; 95% CI, 0.01%-2.45%) than the nonsurgical treatment group (0.71%; 95% CI, 0.28%-15.75%) (odds ratio 0.07; 95% CI, 0.01-0.56). Hangman's fractures are common injuries, and surgical treatment leads to an increase in the rate of

Flow characteristics through a single fracture of artificial fracture system

International Nuclear Information System (INIS)

Park, Byoung Yoon; Bae, Dae Seok; Kim, Chun Soo; Kim, Kyung Su; Koh, Young Kwon; Jeon, Seok Won

2001-04-01

Fracture flow in rock masses is one of the most important issues in petroleum engineering, geology, and hydrogeology. Especially, in case of the HLW disposal, groundwater flow in fractures is an important factor in the performance assessment of the repository because the radionuclides move along the flowing groundwater through fractures. Recently, the characterization of fractures and the modeling of fluid flow in fractures are studied by a great number of researchers. Among those studies, the hydraulic behavior in a single fracture is one of the basic issues for understanding of fracture flow in rockmass. In this study, a fluid flow test in the single fracture made of transparent epoxy replica was carried out to obtain the practical exponent values proposed from the Cubic law and to estimate the flow rates through a single fracture. Not only the relationship between flow rates and the geometry of fracture was studied, but also the various statistical parameters of fracture geometry were compared to the effective transmissivity data obtained from computer simulation.

Fracture Failure of Reinforced Concrete Slabs Subjected to Blast Loading Using the Combined Finite-Discrete Element Method

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Z. M. Jaini

Full Text Available Abstract Numerical modeling of fracture failure is challenging due to various issues in the constitutive law and the transition of continuum to discrete bodies. Therefore, this study presents the application of the combined finite-discrete element method to investigate the fracture failure of reinforced concrete slabs subjected to blast loading. In numerical modeling, the interaction of non-uniform blast loading on the concrete slab was modeled using the incorporation of the finite element method with a crack rotating approach and the discrete element method to model crack, fracture onset and its post-failures. A time varying pressure-time history based on the mapping method was adopted to define blast loading. The Mohr-Coulomb with Rankine cut-off and von-Mises criteria were applied for concrete and steel reinforcement respectively. The results of scabbing, spalling and fracture show a reliable prediction of damage and fracture.

Concurrent and predictive evaluation of malnutrition diagnostic measures in hip fracture inpatients: a diagnostic accuracy study.

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Bell, J J; Bauer, J D; Capra, S; Pulle, R C

2014-03-01

Differences in malnutrition diagnostic measures impact malnutrition prevalence and outcomes data in hip fracture. This study investigated the concurrent and predictive validity of commonly reported malnutrition diagnostic measures in patients admitted to a metropolitan hospital acute hip fracture unit. A prospective, consecutive level II diagnostic accuracy study (n=142; 8 exclusions) including the International Classification of Disease, 10th Revision, Australian Modification (ICD10-AM) protein-energy malnutrition criteria, a body mass index (BMI) Patients were predominantly elderly (median age 83.5, range 50-100 years), female (68%), multimorbid (median five comorbidities), with 15% 4-month mortality. Malnutrition prevalence was lowest when assessed by BMI (13%), followed by MNA-SF (27%), ICD10-AM (48%), albumin (53%) and geriatrician assessment (55%). Agreement between measures was highest between ICD10-AM and geriatrician assessment (κ=0.61) followed by ICD10-AM and MNA-SF measures (κ=0.34). ICD10-AM diagnosed malnutrition was the only measure associated with 48-h mobilisation (35.0 vs 55.3%; P=0.018). Reduced likelihood of home discharge was predicted by ICD-10-AM (20.6 vs 57.1%; P=0.001) and MNA-SF (18.8 vs 47.8%; P=0.035). Bivariate analysis demonstrated ICD10-AM (relative risk (RR)1.2; 1.05-1.42) and MNA-SF (RR1.2; 1.0-1.5) predicted 4-month mortality. When adjusted for age, usual place of residency, comorbidities and time to surgery only ICD-10AM criteria predicted mortality (odds ratio 3.59; 1.10-11.77). Albumin, BMI and geriatrician assessment demonstrated limited concurrent and predictive validity. Malnutrition prevalence in hip fracture varies substantially depending on the diagnostic measure applied. ICD-10AM criteria or the MNA-SF should be considered for the diagnosis of protein-energy malnutrition in frail, multi-morbid hip fracture inpatients.

A Rare Nasal Bone Fracture: Anterior Nasal Spine Fracture

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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.

A COMPARATIVE STUDY OF PROXIMAL FEMUR LOCKING COMPRESSION PLATE VERSUS PROXIMAL FEMORAL NAILING IN THE MANAGEMENT OF COMMINUTED TROCHANTERIC AND SUBTROCHANTERIC FRACTURE

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Satish Koti

2016-11-01

Full Text Available BACKGROUND Fractures of proximal femur and hip are relatively common injuries in elderly individuals constituting 11.6% of total fractures. The latest implant for management of intertrochanteric fracture is Proximal Femoral Locking Compression Plate (PF-LCP. In this study, we compare the clinical outcome of fractures treated by proximal femoral nail with that of proximal femur locking compression plate. MATERIALS AND METHODS The present study consists of 24 elderly patients of peritrochanteric factures of femur satisfying the inclusion criteria who were treated with PF-LCP or PFN in Department of Orthopaedics, S.V.R.R.G.G.H, Tirupati, during a period between December 2013 to October 2015. RESULTS 24 cases were treated with PF-LCP or PFN in a randomised pattern who satisfied inclusion criteria. Intraoperative complication were found to be more with PF-LCP in contrast to PFN. Postoperative rehabilitation was easier with PFN though not statistically significant functional and anatomical outcomes were found to be better with PFN. CONCLUSION Both PFN and PF-LCP have good effectiveness in the treatment of intertrochanteric fractures with the lateral unsubstantial femoral wall in the elderly patients. Each has its own advantages and disadvantages. Further studies with large number of patients and long-term follow up is needed to determine the optimal implant for the internal fixation of comminuted pertrochanteric femoral fractures.

Fracture behavior of circumferentially surface-cracked elbows. Technical report, October 1993--March 1996

International Nuclear Information System (INIS)

Kilinski, T.; Mohan, R.; Rudland, D.; Fleming, M.

1996-12-01

This report presents the results from Task 2 of the Second International Piping Integrity Research Group (IPIRG-2) program. The focus of the Task 2 work was directed towards furthering the understanding of the fracture behavior of long-radius elbows. This was accomplished through a combined analytical and experimental program. J-estimation schemes were developed for both axial and circumferential surface cracks in elbows. Large-scale, quasi-static and dynamic, pipe-system, elbow fracture experiments under combined pressure and bending loads were performed on elbows containing an internal surface crack at the extrados. In conjunction with the elbow experiments, material property data were developed for the A106-90 carbon steel and WP304L stainless steel elbow materials investigated. A comparison of the experimental data with the maximum stress predictions using existing straight pipe fracture prediction analysis methods, and elbow fracture prediction methods developed in this program was performed. This analysis was directed at addressing the concerns regarding the validity of using analysis predictions developed for straight pipe to predict the fracture stresses of cracked elbows. Finally, a simplified fitting flaw acceptance criteria incorporating ASME B2 stress indices and straight pipe, circumferential-crack analysis was developed

Fracture behavior of circumferentially surface-cracked elbows. Technical report, October 1993--March 1996

Energy Technology Data Exchange (ETDEWEB)

Kilinski, T.; Mohan, R.; Rudland, D.; Fleming, M. [and others

1996-12-01

This report presents the results from Task 2 of the Second International Piping Integrity Research Group (IPIRG-2) program. The focus of the Task 2 work was directed towards furthering the understanding of the fracture behavior of long-radius elbows. This was accomplished through a combined analytical and experimental program. J-estimation schemes were developed for both axial and circumferential surface cracks in elbows. Large-scale, quasi-static and dynamic, pipe-system, elbow fracture experiments under combined pressure and bending loads were performed on elbows containing an internal surface crack at the extrados. In conjunction with the elbow experiments, material property data were developed for the A106-90 carbon steel and WP304L stainless steel elbow materials investigated. A comparison of the experimental data with the maximum stress predictions using existing straight pipe fracture prediction analysis methods, and elbow fracture prediction methods developed in this program was performed. This analysis was directed at addressing the concerns regarding the validity of using analysis predictions developed for straight pipe to predict the fracture stresses of cracked elbows. Finally, a simplified fitting flaw acceptance criteria incorporating ASME B2 stress indices and straight pipe, circumferential-crack analysis was developed.

A STUDY OF CLINICAL AND SURGICAL OUTCOME OF FRACTURE NECK OF FEMUR

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Anish G. Cherian

2016-09-01

Full Text Available BACKGROUND Fracture neck of femur has high incidence of complications even with treatment, hence it is also termed as unsolved fracture. Factors making treatment difficult are the blood supply to head, which gets cut off and difficulty in achieving reduction. Impacted fractures can be treated conservatively. If the fracture is undisplaced, a conservative approach may be done or multiple cancellous screws can be used. If the patient’s age is less than 60 years, a closed reduction under C-arm control can be tried. If the reduction is possible, then multiple screw fixations can be done. If reduction is not achieved, then open screw reduction and screw fixation can be done. If the patient is above 60 years of age, then it is preferable to excise the head off and replace it with prosthesis. If the hip is normal, then hemiarthroplasty with a unipolar or bipolar prosthesis can be done. If the hip has pre-existing arthritis, then total hip replacement surgery is advisable. A sincere effort has been put to understand the clinical and surgical outcome of fracture neck of femur in elderly. This paper is intended to help the practicing orthopaedicians to understand the various treatment modalities which is commonly used in practice and also the complications which are associated with the pathology. METHODS  The study was done in the Department of Orthopaedics, Travancore Medical College at Kollam.  The study was done from August 2014 to June 2016.  Eighty cases who attended in the Department of Orthopaedics were taken for the study.  Detailed History and Clinical Examination was conducted. INCLUSION CRITERIA  Both traumatic and pathological fractures were taken up for the study.  Individuals who were aged more than 55 years were taken up for the study. EXCLUSION CRITERIA  Aged less than 55 years were not considered.  All the statistical analysis was done using the latest SPSS software 2015 (California. RESULT Fracture neck of femur

[Posterior partial trochanteric osteotomy for the treatment of the roof involved acetabular fractures].

Science.gov (United States)

Wang, Pan-Feng; Xu, Shuo-Gui; Zhang, Chun-Cai; Fu, Qing-Ge; Zhang, Yun-Tong; Liu, Xin-Wei; Niu, Yun-Fei; Tang, Yang

2013-11-01

To introduce a new trochanteric osteotomy,and evaluate the outcome of the procedure combined a posterior lateral approach in treating acetabular fractures which involving the roof. Between March 2007 and Novmber 2010,30 patients with displaced acetabular fractures involving the dome need trochanteric osteotomy were retrospectively reviewed. There were 21 males and 9 females,ranging in age from 18 to 70 years with an average of 35.2 years at the time of injury. According to Letournel-Judet classification, there were 10 posterior wall fractures,7 posterior column fractures,5 transverse fractures, 2 T-shape fractures, 1 transverse associated with posterior wall fracture, 3 posterior column and wall fractures and 2 bicolumn fractures. The standards of Matta,the modified Merle d'Aubigne-Postel, Medical Research Council were respectively used to evaluate the reduction result, function of hip joint and the strength of hip abduction. All patients were followed up with an average time of 25 months (18 to 40) and all osteotomy sites obtained bone union with an average time of 8.4 weeks (6 to 12). No bone non-union, bone block displaceing, internal fixation looseing and breaking,infection of deep part were found. Seventeen patients got anatomic reduction, 12 got satisfied reduction, and 1 got unsatisfied result according to the criteria of Matta. At final follow-up, function of hip joint obtained excellent results in 11 cases, good in 15, fair in 3 and poor in 1. The strength of the abductors of 3 patients were grade 4 and 27 patients were grade 5. Posterior partial great trochanteric osteotomy can enhance the exposure and provide a more accurate reduction and degrade the difficulty of acetabular fracture fixation without increasing the risk of complications. The method provide a new way for the treatment of the roof involved acetabular fractures.

Fracture of the styloid process associated with the mandible fracture

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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.

Microseismic Monitoring Design Optimization Based on Multiple Criteria Decision Analysis

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Kovaleva, Y.; Tamimi, N.; Ostadhassan, M.

2017-12-01

Borehole microseismic monitoring of hydraulic fracture treatments of unconventional reservoirs is a widely used method in the oil and gas industry. Sometimes, the quality of the acquired microseismic data is poor. One of the reasons for poor data quality is poor survey design. We attempt to provide a comprehensive and thorough workflow, using multiple criteria decision analysis (MCDA), to optimize planning micriseismic monitoring. So far, microseismic monitoring has been used extensively as a powerful tool for determining fracture parameters that affect the influx of formation fluids into the wellbore. The factors that affect the quality of microseismic data and their final results include average distance between microseismic events and receivers, complexity of the recorded wavefield, signal-to-noise ratio, data aperture, etc. These criteria often conflict with each other. In a typical microseismic monitoring, those factors should be considered to choose the best monitoring well(s), optimum number of required geophones, and their depth. We use MDCA to address these design challenges and develop a method that offers an optimized design out of all possible combinations to produce the best data acquisition results. We believe that this will be the first research to include the above-mentioned factors in a 3D model. Such a tool would assist companies and practicing engineers in choosing the best design parameters for future microseismic projects.

Coupled processes in single fractures, double fractures and fractured porous media

International Nuclear Information System (INIS)

Tsang, C.F.

1986-12-01

The emplacement of a nuclear waste repository in a fractured porous medium provides a heat source of large dimensions over an extended period of time. It also creates a large cavity in the rock mass, changing significantly the stress field. Such major changes induce various coupled thermohydraulic, hydromechanic and hydrochemical transport processes in the environment around a nuclear waste repository. The present paper gives, first, a general overview of the coupled processes involving thermal, mechanical, hydrological and chemical effects. Then investigations of a number of specific coupled processes are described in the context of fluid flow and transport in a single fracture, two intersecting fractures and a fractured porous medium near a nuclear waste repository. The results are presented and discussed

Facial Fractures.

Science.gov (United States)

Ghosh, Rajarshi; Gopalkrishnan, Kulandaswamy

2018-06-01

The aim of this study is to retrospectively analyze the incidence of facial fractures along with age, gender predilection, etiology, commonest site, associated dental injuries, and any complications of patients operated in Craniofacial Unit of SDM College of Dental Sciences and Hospital. This retrospective study was conducted at the Department of OMFS, SDM College of Dental Sciences, Dharwad from January 2003 to December 2013. Data were recorded for the cause of injury, age and gender distribution, frequency and type of injury, localization and frequency of soft tissue injuries, dentoalveolar trauma, facial bone fractures, complications, concomitant injuries, and different treatment protocols.All the data were analyzed using statistical analysis that is chi-squared test. A total of 1146 patients reported at our unit with facial fractures during these 10 years. Males accounted for a higher frequency of facial fractures (88.8%). Mandible was the commonest bone to be fractured among all the facial bones (71.2%). Maxillary central incisors were the most common teeth to be injured (33.8%) and avulsion was the most common type of injury (44.6%). Commonest postoperative complication was plate infection (11%) leading to plate removal. Other injuries associated with facial fractures were rib fractures, head injuries, upper and lower limb fractures, etc., among these rib fractures were seen most frequently (21.6%). This study was performed to compare the different etiologic factors leading to diverse facial fracture patterns. By statistical analysis of this record the authors come to know about the relationship of facial fractures with gender, age, associated comorbidities, etc.

"Hidden" Preoperative Blood Loss With Extracapsular Versus Intracapsular Hip Fractures: What Is the Difference?

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Harper, Katharine D; Navo, Paul; Ramsey, Frederick; Jallow, Sainabou; Rehman, Saqib

2017-12-01

Excessive blood loss with hip fracture management has been shown to result in increased rates of complications. Our goal is to compare blood loss and transfusion rates between patients with intracapsular and extracapsular (both intertrochanteric (IT) and subtrochanteric (ST)) hip fractures. 472 patients were evaluated over a five-year period. Those who presented to the hospital with a proximal femur fracture (femoral neck, IT or ST) were considered for the study. Exclusion criteria included polytrauma, gunshot injuries, periprosthetic fractures, and non-operative management. Primary endpoint was hemoglobin (Hgb) drop from admission to day of surgery (DOS); secondary endpoint was need for pre-op transfusion and discharge location. 304 patients were analyzed who sustained a proximal femur fracture. Median IC Hgb drop was 0.6g/dL; median EC Hgb drop was 1.1g/dL from admission to DOS ( p = 0.0272). Rate of pre-operative transfusions was higher in EC (36/194 = 18.6%) than IC fractures (5/105 = 4.5%) ( p = 0.0006), and overall transfusion rates remained higher throughout hospital stay (55.7% EC vs. 32.7% IC; p = 0.0001). Breakdown of bleeding rate and tranfusion rates between IT and ST fractures were not significant ( p = 0.07; p = 0.4483). Extracapsular hip fractures were more likely to be discharged to a skilled nursing facility (SNF) (84.4% EC vs. 73.8% IC; p = 0.027). Intracapsular hip fractures have significantly less pre-operative blood loss and fewer pre-operative transfusions than their extracapsular counterparts. These findings can be used to establish appropriate pre-operative resuscitative efforts, ensuring that hip fracture protocols account for the increased likelihood of blood loss in extracapsular fractures.

Chance Fracture Secondary to a Healed Kyphotic Compression Osteoporotic Fracture

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Teh KK

2009-11-01

Full Text Available Chance fracture is an unstable vertebral fracture, which usually results from a high velocity injury. An elderly lady with a previously healed osteoporotic fracture of the T12 and L1 vertebra which resulted in a severe kyphotic deformity subsequently sustained a Chance fracture of the adjacent L2 vertebrae after a minor fall. The previously fracture left her with a deformity which resulted in significant sagittal imbalance therefore predisposing her to this fracture. This case highlights the importance of aggressive treatment of osteoporotic fractures in order to prevent significant sagittal imbalance from resultant (i.e. kyphotic deformity.

Continuous intercostal nerve blockade for rib fractures: ready for primetime?

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Truitt, Michael S; Murry, Jason; Amos, Joseph; Lorenzo, Manuel; Mangram, Alicia; Dunn, Ernest; Moore, Ernest E

2011-12-01

Providing analgesia for patients with rib fractures continues to be a management challenge. The objective of this study was to examine our experience with the use of a continuous intercostal nerve block (CINB). Although this technique is being used, little data have been published documenting its use and efficacy. We hypothesized that a CINB would provide excellent analgesia, improve pulmonary function, and decrease length of stay (LOS). Consecutive adult blunt trauma patients with three or more unilateral rib fractures were prospectively studied over 24 months. The catheters were placed at the bedside in the extrathoracic, paravertebral location, and 0.2% ropivacaine was infused. Respiratory rate, preplacement (PRE) numeric pain scale (NPS) scores, and sustained maximal inspiration (SMI) lung volumes were determined at rest and after coughing. Parameters were repeated 60 minutes after catheter placement (POST). Hospital LOS comparison was made with historical controls using epidural analgesia. Over the study period, 102 patients met inclusion criteria. Mean age was 69 (21-96) years, mean injury severity score was 14 (9-16), and the mean number of rib fractures was 5.8 (3-10). Mean NPS improved significantly (PRE NPS at rest = 7.5 vs. POST NPS at rest = 2.6, p pain control, and shortens LOS in patients with rib fractures.

Treatment of pathologic spinal fractures with combined radiofrequency ablation and balloon kyphoplasty

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Tzanakakis George

2009-11-01

Full Text Available Abstract Background In oncologic patients with metastatic spinal disease, the ideal treatment should be well tolerated, relieve the pain, and preserve or restore the neurological function. The combination of fluoroscopic guided radiofrequency ablation (RFA and kyphoplasty may fulfill these criteria. Methods We describe three pathological vertebral fractures treated with a combination of fluoroscopic guided RFA and kyphoplasty in one session: a 62-year-old man suffering from a painful L4 pathological fracture due to a plasmocytoma, a 68-year-old man with a T12 pathological fracture from metastatic hepatocellular carcinoma, and a 71-year-old man with a Th12 and L1 pathological fracture from multiple myeloma. Results The choice of patients was carried out according to the classification of Tomita. Visual analog score (VAS and Oswestry disability index (ODI were used for the evaluation of the functional outcomes. The treatment was successful in all patients and no complications were reported. The mean follow-up was 6 months. Marked pain relief and functional restoration was observed. Conclusion In our experience the treatment of pathologic spinal fractures with combined radiofrequency ablation and balloon kyphoplasty is safe and effective for immediate pain relief in painful spinal lesions in neurologically intact patients.

Hip Fracture

Science.gov (United States)

... hip fractures in people of all ages. In older adults, a hip fracture is most often a result of a fall from a standing height. In people with very weak bones, a hip fracture can occur simply by standing on the leg and twisting. Risk factors The rate of hip fractures increases substantially with ...

Development of statewide geriatric patients trauma triage criteria.

Science.gov (United States)

Werman, Howard A; Erskine, Timothy; Caterino, Jeffrey; Riebe, Jane F; Valasek, Tricia

2011-06-01

The geriatric population is unique in the type of traumatic injuries sustained, physiological responses to those injuries, and an overall higher mortality when compared to younger adults. No published, evidence-based, geriatric-specific field destination criteria exist as part of a statewide trauma system. The Trauma Committee of the Ohio Emergency Medical Services (EMS) Board sought to develop specific criteria for geriatric trauma victims. A literature search was conducted for all relevant literature to determine potential, geriatric-specific, field-destination criteria. Data from the Ohio Trauma Registry were used to compare elderly patients, defined as age >70 years, to all patients between the ages of 16 to 69 years with regards to mortality risk in the following areas: (1) Glasgow Coma Scale (GCS) score; (2) systolic blood pressure (SBP); (3) falls associated with head, chest, abdominal or spinal injury; (4) mechanism of injury; (5) involvement of more than one body system as defined in the Barell matrix; and (6) co-morbidities and motor vehicle collision with one or more long bone fracture. For GCS score and SBP, those cut-off points with equal or greater risk of mortality as compared to current values were chosen as proposed triage criteria. For other measures, any criterion demonstrating a statistically significant increase in mortality risk was included in the proposed criteria. The following criteria were identified as geriatric-specific criteria: (1) GCS score trauma; (2) SBP trauma. In addition, these data suggested that elderly patients with specific co-morbidities be given strong consideration for evaluation in a trauma center. The state of Ohio is the first state to develop evidence-based geriatric-specific field-destination criteria using data from its state-mandated trauma registry. Further analysis of these criteria will help determine their effects on over-triage and under-triage of geriatric victims of traumatic injuries and the impact on the

Ankle fractures have features of an osteoporotic fracture.

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Lee, K M; Chung, C Y; Kwon, S S; Won, S H; Lee, S Y; Chung, M K; Park, M S

2013-11-01

We report the bone attenuation of ankle joint measured on computed tomography (CT) and the cause of injury in patients with ankle fractures. The results showed age- and gender-dependent low bone attenuation and low-energy trauma in elderly females, which suggest the osteoporotic features of ankle fractures. This study was performed to investigate the osteoporotic features of ankle fracture in terms of bone attenuation and cause of injury. One hundred ninety-four patients (mean age 51.0 years, standard deviation 15.8 years; 98 males and 96 females) with ankle fracture were included. All patients underwent CT examination, and causes of injury (high/low-energy trauma) were recorded. Mean bone attenuations of the talus, medial malleolus, lateral malleolus, and distal tibial metaphysis were measured on CT images. Patients were divided into younger age (fractures than the younger age group. With increasing age, bone attenuations tended to decrease and the difference of bone attenuation between the genders tended to increase in the talus, medial malleolus, lateral malleolus, and distal tibial metaphysis. Ankle fracture had features of osteoporotic fracture that is characterized by age- and gender-dependent low bone attenuation. Ankle fracture should not be excluded from the clinical and research interest as well as from the benefit of osteoporosis management.

The Role of Postoperative Antibiotics in Mandible Fractures: A Systematic Review of the Literature.

Science.gov (United States)

Shridharani, Sachin M; Berli, Jens; Manson, Paul N; Tufaro, Anthony P; Rodriguez, Eduardo D

2015-09-01

Little debate exists regarding the use of preoperative and perioperative antibiotic prophylaxis in the setting of mandibular fracture management; however, employing postoperative prophylactic antibiotics remains an inexact science based on experience rather than evidence. In this systematic review, the authors evaluate scientific literature and report results of an international survey that provide information regarding current practices of the plastic surgery community. Systematic literature review was performed using Medline, Embase, PubMed, and Cochrane databases to identify studies evaluating use of antibiotics in patients suffering from mandible fractures. Level 1, 2, and large retrospective studies were included. Case reports were excluded. Additionally, an E-survey was distributed to all ASPS members and data were collected over a 5-month period through SurveyMonkey. Four hundred twenty-seven articles published before December 2012 were identified. Seventy-one articles met inclusion criteria. Five articles remained when exclusion criteria were applied.ASPS member survey demonstrated 13% response rate (687 responses/5299 questionnaires). Of respondents, 75% placed patients (ORIF group) with open mandible fractures on prophylactic antibiotics for up to 3 days (44.1%), 1 week (54.8%), and more than 1 week (1.1%). Of respondents, 51% placed patients (ORIF group) with closed mandible fracture on prophylactic antibiotics for up to 3 days (50.5%), 1 week (48.6%), and more than 1 week (1%). Critical literature review demonstrates a trend towards no postoperative antibiotic coverage (>24 hours) in patients undergoing mandibular ORIF. There is further need for prospective, randomized control trials with a standardized regimen. Our survey elucidates the variability of plastic surgeons' clinical practices.

A clinical evaluation of alternative fixation techniques for medial malleolus fractures.

Science.gov (United States)

Barnes, Hayley; Cannada, Lisa K; Watson, J Tracy

2014-09-01

Medial malleolus fractures have traditionally been managed using partially threaded screws and/or Kirschner wire fixation. Using these conventional techniques, a non-union rate of as high as 20% has been reported. In addition too many patients complaining of prominent hardware as a source of pain post-fixation. This study was designed to assess the outcomes of medial malleolar fixation using a headless compression screw in terms of union rate, the need for hardware removal, and pain over the hardware site. Saint Louis University and Mercy Medical Center, Level 1 Trauma Centers, St. Louis, MO. After IRB approval, we used billing records to identify all patients with ankle fractures involving the medial malleolus. Medical records and radiographs were reviewed to identify patients with medial malleolar fractures treated with headless compression screw fixation. Our inclusion criteria included follow-up until full weight bearing and a healed fracture. Follow-up clinical records and radiographs were reviewed to determine union, complication rate and perception of pain over the site of medial malleolus fixation. Sixty-four ankles were fixed via headless compression screws and 44 had adequate follow-up for additional evaluation. Seven patients had isolated medial malleolar fractures, 23 patients had bimalleolar fractures, and 14 patients had trimalleolar fractures. One patient (2%) required hardware removal due to cellulitis. One patient (2%) had a delayed union, which healed without additional intervention. Ten patients (23%) reported mild discomfort to palpation over the medial malleolus. The median follow-up was 35 weeks (range: 12-208 weeks). There were no screw removals for painful hardware and no cases of non-union. Headless compression screws provide effective compression of medial malleolus fractures and result in good clinical outcomes. The headless compression screw is a beneficial alternative to the conventional methods of medial malleolus fixation. Copyright �

[Treatment of calcaneal avulsion fractures with twinfix suture anchors fixation].

Science.gov (United States)

Zhao, Bin-xiu; Wang, Kun-zheng; Wang, Chun-sheng; Xie, Yue; Dai, Zhi-tang; Liu, Gang; Liu, Wei-dong

2011-06-01

For the calcaneal avulsion fracture, the current method is more commonly used screws or Kirschner wire to fix fracture fragment. This article intended to explore the feasibility and clinical efficacy for the treatment of avulsion fractures with TwinFix suture anchors. From July 2007 to November 2010, 21 patients were reviewed, including 15 males and 6 females, ranging in age from 49 to 65 years,with a mean of 58.7 years. Twelve patients had nodules in the right heel and 9 patients had nodules in the left heel. All the patients had closed fractures. The typical preoperative symptoms of the patients included pain in the upper heel and weak in heel lift. Body examination results: palpable sense of bone rubbing in the back of the heel, and swelling in the heel. Surgery treatment with TwinFix suture anchors performed as follows : to fix TwinFix suture anchors into the calcaneal body, then to drill the fracture block, to make the double strand suture through the fracture holes, to knot the suture eachother to fix the block, and to use stitch to fix the remaining suture in the Achilles tendon in order to improve the block fixation. The criteria of the AOFAS Foot and Ankle Surgery by the United States Association of ankle-rear foot functional recovery was used to evaluate the Achilles tendon. Total average score was (95.5 +/- 3.12) points, including pain items of(38.5 +/- 2.18) points,the average score of functional items of (49.5 +/- 3.09) points,and power lines of 10 points in all patients. Twenty-one patients got an excellent result, 16 good and 5 poor. The methods of treatment for the calcaneal avulsion fractures with TwinFix suture anchors is a simple operation, and have excellent clinical effect, which is worthy of promotion.

Hydraulic Fracturing At Sedimentary Basin Scale Fracturation hydraulique à l'échelle des bassins sédimentaires

Directory of Open Access Journals (Sweden)

Schneider F.

2006-12-01

Full Text Available One key point for simulating the hydraulic fracturing at basin scale, is to be able to compute the stress tensor. This is generally not addressed in basin model because of the complexity of this problem. In order to get access to the stress tensor we have to assume that:- one of the principal stress is vertical and equals the overburden weight;- the horizontal stress is deduced from the vertical stress with the K0 coefficient that is a function of depth and of the tectonical setting. Consolidation is considered here as the combined effect of the mechanical compaction and the chemical compaction. The mechanical compaction is mainly caused by the rearrangement of grains during burial and could be represented at the macroscopical scale by an elastoplastic rheology. The chemical compaction is considered here as resulting from dissolution-precipitation mechanisms, generally induced by stress (pressure-solution. The chemical compaction could be represented at the macroscopical scale by a viscoplastic rheology. The complete elastoplastic yield is defined by the union of the consolidation elastoplastic yield and of the different failure criteria that could be seen as elastobrittle yields. Thus, the elastoplastic yield is composed of six elementary elastoplastic yields which define the onset of vertical compaction, horizontal compaction, vertical tensile fracturing, horizontal tensile fracturing, subvertical shear fracturing, and subhorizontal shear fracturing. Due to the consolidation, most of the parameters that describe the physical properties of the sediments evolve with the geological times. One difficulty is to quantify the degree of evolution of the porous medium during its geological history. Here, we have chosen to measure the evolution of the sediments by their porosity. The local simulations showed that fracturing may occur is numerous configurations. Some of these configurations indicate that the sediments can reach the limit of its elastic

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

OpenAIRE

Gulbahar, Gultekin; Kaplan, Tevfik; Turker, Hasan Bozkurt; Gundogdu, Ahmet Gokhan; Han, Serdar

2015-01-01

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 en...

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

Science.gov (United States)

Gulbahar, Gultekin; Kaplan, Tevfik; Turker, Hasan Bozkurt; Gundogdu, Ahmet Gokhan; Han, Serdar

2015-01-01

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.

Whole-body low-dose computed tomography in multiple myeloma staging: Superior diagnostic performance in the detection of bone lesions, vertebral compression fractures, rib fractures and extraskeletal findings compared to radiography with similar radiation exposure.

Science.gov (United States)

Lambert, Lukas; Ourednicek, Petr; Meckova, Zuzana; Gavelli, Giampaolo; Straub, Jan; Spicka, Ivan

2017-04-01

The primary objective of the present prospective study was to compare the diagnostic performance of conventional radiography (CR) and whole-body low-dose computed tomography (WBLDCT) with a comparable radiation dose reconstructed using hybrid iterative reconstruction technique, in terms of the detection of bone lesions, skeletal fractures, vertebral compressions and extraskeletal findings. The secondary objective was to evaluate lesion attenuation in relation to its size. A total of 74 patients underwent same-day skeletal survey by CR and WBLDCT. In CR and WBLDCT, two readers assessed the number of osteolytic lesions at each region and stage according to the International Myeloma Working Group (IMWG) criteria. A single reader additionally assessed extraskeletal findings and their significance, the number of vertebral compressions and bone fractures. The radiation exposure was 2.7±0.9 mSv for WBLDCT and 2.5±0.9 mSv for CR (P=0.054). CR detected bone involvement in 127 out of 486 regions (26%; Prib fractures compared with CR (188 vs. 47; Pfractures, vertebral compressions and extraskeletal findings, which results in up- or downstaging in 24% patients according to the IMWG criteria. The attenuation of osteolytic lesions can be measured with the avoidance of the partial volume effect.

Total elbow arthroplasty for the treatment of distal humeral fractures.

Science.gov (United States)

Gallucci, G L; Larrondo Calderón, W; Boretto, J G; Castellaro Lantermo, J A; Terán, J; de Carli, P

2016-01-01

To report the clinical-functional outcomes of the treatment of humeral distal fractures with a total elbow prosthesis. This retrospective study was performed in two surgical centres. A total of 23patients were included, with a mean age of 79years, and of which 21 were women. The inclusion criteria were: patients with humeral distal fractures, operated on using a Coonrad-Morrey prosthesis, and with a follow-up of more than one year. According to AO classification, 15fractures were type C3, 7 C2 and 1 A2. All patients were operated on without de-insertion of the extensor mechanism. The mean follow-up was 40 months. Flexor-extension was 123-17°, with a total mobility arc of 106° (80% of the contralateral side). Pain, according to a visual analogue scale was 1. The Mayo Elbow Performance Index (MEPI) was 83 points. Excellent results were obtained in 8 patients, good in 13, medium in 1, and poor in 1. The mean DASH (disability) score was 24 points. Treatment of humeral distal fractures with total elbow arthroplasty could be a good treatment option, but indications must be limited to patients with complex fractures, poor bone quality, with osteoporosis and low functional demands. In younger patients, the use is limited to serious cases where there is no other treatment option. Level of Evidence IV. Copyright © 2016 SECOT. Published by Elsevier Espana. All rights reserved.

A ductile fracture criterion with Zener-Hollomon parameter of pure molybdenum sheet in thermal forming

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Wang Chu

2015-01-01

Full Text Available Formability of pure molybdenum in thermal forming process has been greatly improved, but it is still hard to avoid the generation of rupture and other quality defects. In this paper, a ductile fracture criterion of pure molybdenum sheet in thermal forming was established by considering the plastic deformation capacity of material and stress states, which can be used to describe fracture behaviour and critical rupture prediction of pure molybdenum sheet during hot forming process. Based on the isothermal uniaxial tensile tests which performed at 993 to 1143 K with strain rate range from 0.0005 to 0.2 s−1, the material parameters are calculated by the combination method of experiment with FEsimulation. Based on the observation, new fracture criteria can be expressed as a function of Zener-Hollomon parameter. The critical fracture value that calculated by Oyane-Sato criterion increases with increasing temperature and decreasing strain rate. The ductile fracture criterion with Zener-Hollomon parameter of pure molybdenum in thermal forming is proposed.

Relationships between fractures

Science.gov (United States)

Peacock, D. C. P.; Sanderson, D. J.; Rotevatn, A.

2018-01-01

Fracture systems comprise many fractures that may be grouped into sets based on their orientation, type and relative age. The fractures are often arranged in a network that involves fracture branches that interact with one another. Interacting fractures are termed geometrically coupled when they share an intersection line and/or kinematically coupled when the displacements, stresses and strains of one fracture influences those of the other. Fracture interactions are characterised in terms of the following. 1) Fracture type: for example, whether they have opening (e.g., joints, veins, dykes), closing (stylolites, compaction bands), shearing (e.g., faults, deformation bands) or mixed-mode displacements. 2) Geometry (e.g., relative orientations) and topology (the arrangement of the fractures, including their connectivity). 3) Chronology: the relative ages of the fractures. 4) Kinematics: the displacement distributions of the interacting fractures. It is also suggested that interaction can be characterised in terms of mechanics, e.g., the effects of the interaction on the stress field. It is insufficient to describe only the components of a fracture network, with fuller understanding coming from determining the interactions between the different components of the network.

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.

Proximal femoral fractures.

Science.gov (United States)

Webb, Lawrence X

2002-01-01

Fractures of the proximal femur include fractures of the head, neck, intertrochanteric, and subtrochanteric regions. Head fractures commonly accompany dislocations. Neck fractures and intertrochanteric fractures occur with greatest frequency in elderly patients with a low bone mineral density and are produced by low-energy mechanisms. Subtrochanteric fractures occur in a predominantly strong cortical osseous region which is exposed to large compressive stresses. Implants used to address these fractures must be able to accommodate significant loads while the fractures consolidate. Complications secondary to these injuries produce significant morbidity and include infection, nonunion, malunion, decubitus ulcers, fat emboli, deep venous thrombosis, pulmonary embolus, pneumonia, myocardial infarction, stroke, and death.

[Effect of axial stress stimulation on tibial and fibular open fractures healing after Taylor space stent fixation].

Science.gov (United States)

Ge, Qihang; Wan, Chunyou; Liu, Yabei; Ji, Xu; Ma, Jihai; Cao, Haikun; Yong, Wei; Liu, Zhao; Zhang, Ningning

2017-08-01

To investigate the effect of axial stress stimulation on tibial and fibular open fractures healing after Taylor space stent fixation. The data of 45 cases with tibial and fibular open fractures treated by Taylor space stent fixation who meet the selection criteria between January 2015 and June 2016 were retrospectively analysed. The patients were divided into trial group (23 cases) and control group (22 cases) according to whether the axial stress stimulation was performed after operation. There was no significant difference in gender, age, affected side, cause of injury, type of fracture, and interval time from injury to operation between 2 groups ( P >0.05). The axial stress stimulation was performed in trial group after operation. The axial load sharing ratio was tested, and when the value was less than 10%, the external fixator was removed. The fracture healing time, full weight-bearing time, and external fixator removal time were recorded and compared. After 6 months of external fixator removal, the function of the limb was assessed by Johner-Wruhs criteria for evaluation of final effectiveness of treatment of tibial shaft fractures. There were 2 and 3 cases of needle foreign body reaction in trial group and control group, respectively, and healed after symptomatic anti allergic treatment. All the patients were followed up 8-12 months with an average of 10 months. All the fractures reached clinical healing, no complication such as delayed union, nonunion, or osteomyelitis occurred. The fracture healing time, full weight-bearing time, and external fixator removal time in trial group were significantly shorter than those in control group ( P good in 6 cases, fair in 3 cases, and poor in 1 case in trial group, with an excellent and good rate of 82.6%; and was excellent in 5 cases, good in 10 cases, fair in 4 cases, and poor in 3 cases in control group, with an excellent and good rate of 68.2%, showing significant difference between 2 groups ( Z =-2.146, P =0

The effect of defects on structural failure: A two-criteria approach

International Nuclear Information System (INIS)

Dowling, A.R.; Townley, C.H.A.

1976-01-01

The two-criteria approach to the study of defects in structures assumes that failure occurs when the applied load reaches the lower of either a load to cause brittle failure in accordance with the theories of linear elastic fracture mechanics or a collapse load dependent on the ultimate stress of the material and the structural geometry. This simple approach is described and compared with previously published experimental results for various geometries and materials. The simplicity of this method of defect analysis lies in the fact that each criterion is sufficiently well understood to permit scaling and geometry changes to be accommodated readily. It becomes apparent that a sizeable transition region exists between the two criteria but this can be described in an expression relating the criteria. This expression adequately predicts the behaviour of cracked structures of both simple and complex geometry. A design curve for defect assessment is proposed for which it is unnecessary to consider the transition region. (author)

Experimental and statistical study on fracture boundary of non-irradiated Zircaloy-4 cladding tube under LOCA conditions

Science.gov (United States)

Narukawa, Takafumi; Yamaguchi, Akira; Jang, Sunghyon; Amaya, Masaki

2018-02-01

For estimating fracture probability of fuel cladding tube under loss-of-coolant accident conditions of light-water-reactors, laboratory-scale integral thermal shock tests were conducted on non-irradiated Zircaloy-4 cladding tube specimens. Then, the obtained binary data with respect to fracture or non-fracture of the cladding tube specimen were analyzed statistically. A method to obtain the fracture probability curve as a function of equivalent cladding reacted (ECR) was proposed using Bayesian inference for generalized linear models: probit, logit, and log-probit models. Then, model selection was performed in terms of physical characteristics and information criteria, a widely applicable information criterion and a widely applicable Bayesian information criterion. As a result, it was clarified that the log-probit model was the best among the three models to estimate the fracture probability in terms of the degree of prediction accuracy for both next data to be obtained and the true model. Using the log-probit model, it was shown that 20% ECR corresponded to a 5% probability level with a 95% confidence of fracture of the cladding tube specimens.

ROCK FRACTURES NEAR FAULTS: SPECIFIC FEATURES OF STRUCTURAL‐PARAGENETIC ANALYSIS

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Yu. P. Burzunova

2017-01-01

by using special criteria to estimate the diagrams, and the reliability of the solutions is thus ensured. This paper considers various problems related to interpretations of natural fracture systems, concerning the angles between the conjugate joint sets, the presence of non‐standard fracture parageneses, fault zones of mixed types, and structural‐material inhomogeneities. The recommendations based on our experience of selection and processing of input field data can be viewed as a sup‐ plement to the method of analysis used for specialized mapping of faults zones and detection of stress fields [Seminsky, 2014, 2015]. The discussed information can be useful for those who are willing to successfully use this new approach to investigate the fault systems in the upper crust and solve applied and fundamental problems in the studies of faulting.

Ultrasonography as a better diagnostic efficiency in rib fracture

OpenAIRE

UZUN, Metin; BEKSAÇ, Burak; KARATAŞ, Adnan; KÜÇÜKDURMAZ, Fatih; KIRCALI, Bahar ANAYURDU; TETİK, Cihangir

2013-01-01

In this study, our aim was to demonstrate the need of use of ultrasonography in rib fractures in order not to face medicolegal problems. One hundred patients admitted to our emergency service with mild to moderate blunt thorax trauma were included in our study prospectively. The inclusion criteria were pain upon palpation of ribs, deep inspiration, coughing but no any other pathologies like a pneumothorax, hemothorax. All patients are evaluated with ultrasonography (USG) and direct X-rays. X-...

Evaluation of Fracture and Osteotomy Union in the Setting of Osteogenesis Imperfecta: Reliability of the Modified Radiographic Union Score for Tibial Fractures (RUST).

Science.gov (United States)

Franzone, Jeanne M; Finkelstein, Mark S; Rogers, Kenneth J; Kruse, Richard W

2017-09-08

Evaluation of the union of osteotomies and fractures in patients with osteogenesis imperfecta (OI) is a critical component of patient care. Studies of the OI patient population have so far used varied criteria to evaluate bony union. The radiographic union score for tibial fractures (RUST), which was subsequently revised to the modified RUST, is an objective standardized method of evaluating fracture healing. We sought to evaluate the reliability of the modified RUST in the setting of the tibias of patients with OI. Tibial radiographs of 30 patients with OI fractures, or osteotomies were scored by 3 observers on 2 separate occasions. Each of the 4 cortices was given a score (1=no callus, 2=callus present, 3=bridging callus, and 4=remodeled, fracture not visible) and the modified RUST is the sum of these scores (range, 4 to 16). The interobserver and intraobserver reliabilities were evaluated using intraclass coefficients (ICC) with 95% confidence intervals. The ICC representing the interobserver reliability for the first iteration of scores was 0.926 (0.864 to 0.962) and for the second series was 0.915 (0.845 to 0.957). The ICCs representing the intraobserver reliability for each of the 3 reviewers for the measurements in series 1 and 2 were 0.860 (0.707 to 0.934), 0.994 (0.986 to 0.997), and 0.974 (0.946 to 0.988). The modified RUST has excellent interobserver and intraobserver reliability in the setting of OI despite challenges related to the poor quality of the bone and its dysplastic nature. The application and routine use of the modified RUST in the OI population will help standardize our evaluation of osteotomy and fracture healing. Level III-retrospective study of nonconsecutive patients.

Dating fractures and fracture movement in the Lac du Bonnet Batholith

International Nuclear Information System (INIS)

Gascoyne, M.; Brown, A.; Ejeckam, R.B.; Everitt, R.A.

1997-04-01

This report examines and summarizes all work that has been done from 1980 to the present in determining the age of rock crystallization, fracture initiation, fracture reactivation and rates of fracture movement in the Lac du Bonnet Batholith to provide information for Atomic Energy of Canada Limited's (AECL) Canadian Nuclear Fuel Waste Management Program. Geological and petrographical indicators of relative age (e.g. cross-cutting relationships, sequences of fracture infilling minerals, P-T characteristics of primary and secondary minerals) are calibrated with radiometric age determinations on minerals and whole rock samples, using 87 Rb- 87 Sr, 40 K- 39 Ar, 40 Ar- 39 Ar and fission track methods. Most fractures and fracture zones inclined at low angles are found to be ancient features, first formed in the Early Proterozoic under conditions of deuteric alteration. Following some movement on fractures in the Late Proterozoic and Early Paleozoic, reactivation of fractures during the Pleistocene is established from uranium-series dating methods and use of stable isotopic contents of fracture infilling minerals (mainly calcite). Some indication of movement on fracture zones during the Pleistocene is given by electron spin resonance dating techniques on fault gouge. The slow rate of propagation of fractures is indicated by mineral infillings, their P-T characteristics and U-series calcite ages in a fracture in sparsely fractured rock, accessible from AECL's Underground Research Laboratory. These results collectively indicate that deep fractures observed in the batholith are ancient features and the fracturing and jointing in the upper 200 m is relatively recent (< 1 Ma) and largely a result of stress release. (author)

Guideline-Driven Care Improves Outcomes in Patients with Traumatic Rib Fractures.

Science.gov (United States)

Flarity, Kathleen; Rhodes, Whitney C; Berson, Andrew J; Leininger, Brian E; Reckard, Paul E; Riley, Keyan D; Shahan, Charles P; Schroeppel, Thomas J

2017-09-01

There is no established national standard for rib fracture management. A clinical practice guideline (CPG) for rib fractures, including monitoring of pulmonary function, early initiation of aggressive loco-regional analgesia, and early identification of deteriorating respiratory function, was implemented in 2013. The objective of the study was to evaluate the effect of the CPG on hospital length of stay. Hospital length of stay (LOS) was compared for adult patients admitted to the hospital with rib fracture(s) two years before and two years after CPG implementation. A separate analysis was done for the patients admitted to the intensive care unit (ICU). Over the 48-month study period, 571 patients met inclusion criteria for the study. Pre-CPG and CPG study groups were well matched with few differences. Multivariable regression did not demonstrate a difference in LOS (B = -0.838; P = 0.095) in the total study cohort. In the ICU cohort (n = 274), patients in the CPG group were older (57 vs 52 years; P = 0.023) and had more rib fractures (4 vs 3; P = 0.003). Multivariable regression identified a significant decrease in LOS for those patients admitted in the CPG period (B = -2.29; P = 0.019). Despite being significantly older with more rib fractures in the ICU cohort, patients admitted after implementation of the CPG had a significantly reduced LOS on multivariable analysis, reducing LOS by over two days. This structured intervention can limit narcotic usage, improve pulmonary function, and decrease LOS in the most injured patients with chest trauma.

Determination techniques of characteristics of brittle fracture for materials on the CMEA 1-35 problem

International Nuclear Information System (INIS)

Makhutov, N.A.; Tananov, A.I.; Koshelev, P.F.; Zatsarinnyj, V.V.

1981-01-01

The problems concerning the development and improvement of the investigation techniques and the evaluation of the resistance to brittle fracture of a wide class of materials (the reactor ones, in particular) under different conditions of loading using modern test means are considered in the review. It is reflected in the plan of works on the theme 1-35.3 ''Development of the methods of determination of resistance to brittle fracture of the materials and elements of construct Specialists from CMEA member-countries took an active part in its implementation. The development of the 1-35.3 theme presupposes the creation of scientific bases of calculation methods of the details of machines and elements of constructions according to the criteria of resistance to brittle fracture. The results obtained when using the methods of fracture mechanics are of significant importance in the substantiation of strength and admissible defectiveness of large-size constructions operating under the extremum conditions [ru

Emergency ultrasound in the detection of pediatric long-bone fractures.

Science.gov (United States)

Barata, Isabel; Spencer, Robert; Suppiah, Ara; Raio, Christopher; Ward, Mary Frances; Sama, Andrew

2012-11-01

.9%-99.2%) and 85.5% (95% CI, 72.8%-93.1%), respectively, and the positive and negative predictive values were 83.7% (95% CI, 68.8%-92.2%) and 96% (95% CI, 84.9%-99.3%), respectively. Overall, ultrasound detected 100.0% of diaphyseal fractures and 27 (93.1%) of 29 end-of-bone or near-joint fractures.Radiography revealed 6 displacements that met the published criteria for reduction, all of which were also revealed by ultrasound. The overall sensitivity and specificity for ultrasound identifying the need for reduction were 100.0% (95% CI, 51.7%-100.0%) and 97.3% (95% CI, 84.2%-99.9%), respectively, and positive and negative predictive values were 85.7% (95% CI, 42.0%-99.2%) and 100.0% (95% CI, 88.0%-100.0%), respectively. Emergency department physician-performed focused ultrasound was more accurate in detecting diaphyseal fractures than in detecting fractures in the metaphysis and/or epiphysis. The high sensitivity and specificity of ultrasound in the detection of long-bone fractures and the need for reduction support the use of ultrasound in the evaluation of suspected long-bone fractures in children.

Pathologic C-spine fracture with low risk mechanism and normal physical exam.

Science.gov (United States)

Hunter, Andrew; McGreevy, Jolion; Linden, Judith

2017-09-01

Cervical spinal fracture is a rare, but potentially disabling complication of trauma to the neck. Clinicians often rely on clinical decision rules and guidelines to decide whether or not imaging is necessary when a patient presents with neck pain. Validated clinical guidelines include the Canadian C-Spine Rule and the Nexus criteria. Studies suggest that the risks of a pathologic fracture from a simple rear end collision are negligible. We present a case of an individual who presented to an emergency department (ED) after a low speed motor vehicle collision complaining of lateral neck pain and had multiple subsequent visits for the same complaint with negative exam findings. Ultimately, he was found to have a severely pathologic cervical spine fracture with notable cord compression. Our objective is to discuss the necessity to incorporate clinical decision rules with physician gestalt and the need to take into account co-morbidities of a patient presenting after a minor MVC. Copyright © 2017 Elsevier Inc. All rights reserved.

Physical fracture properties (fracture surfaces as information sources; crackgrowth and fracture mechanisms; exemples of cracks)

International Nuclear Information System (INIS)

Meny, Lucienne.

1979-06-01

Fracture surfaces are considered as a useful source of informations: an introduction to fractography is presented; the fracture surface may be observed through X ray microanalysis, and other physical methods such as Auger electron spectroscopy or secundary ion emission. The mechanisms of macroscopic and microscopic crackgrowth and fracture are described, in the case of unstable fracture (cleavage, ductile with shear, intergranular brittleness) and of progressive crack propagation (creep, fatigue). Exemples of cracks are presented in the last chapter [fr

Correlation of Functional and Nutritional Status in Elderly Hip Fracture in a Hospital of High Complexity

OpenAIRE

Chavarro, Diego Andrés; Hospital Universitario San Ignacio; Gutiérrez, William Arbey; Pontificia Universidad Javeriana; Cañón, Arleth Patricia; Pontificia Universidad Javeriana

2014-01-01

The importance of hip fractures is given not only by their high frequency, but also the associated mortality, morbidity and high economic and social cost.Aim: To determine the functionality of the individual after suffering a fall and consequently a hip fracture.Methods: Prospective observational study analytical. Results: 44 patients who met the inclusion criteria were included. The average age was 81.8 SD ± 8; 59 % were women. Of the total of 44 patients revealed that 13 patients were indep...

[PRELIMINARY APPLICATION OF VIRTUAL PREOPERATIVE RECONSTRUCTION PLANNING IN Pilon FRACTURES].

Science.gov (United States)

Wang Xiaoping; Wei, Zhantu; Huang, Jian; Chen, Luyao; Hu, Shiqiang; Wu, Weiwei; Tu, Yumin; Guo, Sheng; Xu, Guotai; Deng, Zhicheng

2016-01-01

To investigate the application value of three-dimensional reconstruction and virtual preoperative planning for Pilon fractures. Between July 2010 and June 2014, 16 patients with closed Pilon fracture were treated, including 12 males and 4 females with an average age of 36.5 years (range, 22-53 years) and a mean disease duration of 10.2 days (range, 6-14 days). According to AO/Orthopaedic Trauma Association (AO/OTA) typing, 2 cases were rated as 43.B2 type, 3 cases as 43.B3 type, 3 cases as 43.C1 type, 2 cases as 43.C2 type, and 6 cases as 43.C3 type. The preoperative CT data from 16 patients were imported into Mimics10.01 software to establish the detailed fracture three-dimensional digital models. Virtual operation of fracture reduction and implanting internal fixation was performed on the models, and the optional surgical planning was made. Based on the virtual preoperative planning, operations were performed. Established detailed three-dimensional Pilon fracture digital models could perfectly reflect the fracture characteristics, could be observed at any direction, and aided for fracture classification accurately. Virtual fracture operations of reduction, internal fixation and other could be performed to simulate the clinical operation, which could assist the surgeon better preoperative planning in achieving visual presentation and improving the communication. The operation time was 70-130 minutes (mean, 87.8 minutes); intraoperative blood loss volume was 30-150 mL (mean, 71.9 mL). The wounds healed by first intension in all patients. The mean follow-up time was 11.6 months (range, 8-18 months). Postoperative radiological results at 3 groups showed good anatomic reduction according to the Burwell-Charnley criteria, and the fracture healing time was 3-6 months (mean, 3.7 months). There was no complication of internal fixation loosening or breakage during follow-up. The American Orthopedic Foot and Ankle Society (AOFAS) score was 71-100 (mean, 92.3); the results

Influence of bone mineral density measurement on fracture risk assessment tool® scores in postmenopausal Indian women.

Science.gov (United States)

Daswani, Bhavna; Desai, Meena; Mitra, Sumegha; Gavali, Shubhangi; Patil, Anushree; Kukreja, Subhash; Khatkhatay, M Ikram

2016-03-01

Fracture risk assessment tool® calculations can be performed with or without addition of bone mineral density; however, the impact of this addition on fracture risk assessment tool® scores has not been studied in Indian women. Given the limited availability and high cost of bone mineral density testing in India, it is important to know the influence of bone mineral density on fracture risk assessment tool® scores in Indian women. Therefore, our aim was to assess the contribution of bone mineral density in fracture risk assessment tool® outcome in Indian women. Apparently healthy postmenopausal Indian women (n = 506), aged 40-72 years, without clinical risk factors for bone disease, were retrospectively selected, and their fracture risk assessment tool® scores calculated with and without bone mineral density were compared. Based on WHO criteria, 30% women were osteoporotic, 42.9% were osteopenic and 27.1% had normal bone mineral density. Fracture risk assessment tool® scores for risk of both major osteoporotic fracture and hip fracture significantly increased on including bone mineral density (P women eligible without bone mineral density was 0 and with bone mineral density was 1, P > 0.05, whereas, for hip fracture risk number of women eligible without bone mineral density was 2 and with bone mineral density was 17, P Indian women. © The Author(s) 2016.

Total elbow arthroplasty in distal humerus fracture in patients older than 65 years.

Directory of Open Access Journals (Sweden)

Gerardo Gallucci

2016-05-01

Full Text Available Objective To report the clinical-functional results of the treatment of humeral distal fractures with a total elbow prosthesis in patients older than 65 years old. Material and methods This retrospective paper was performed in two surgical centers. Criteria inclusion were: patients with humeral distal fractures, > 65 years, operated on with Coonrad-Morrey prostheses, and with a follow-up of  >1 year. Twenty-one patients were included. Twenty were women with an average age of 79 years old. According to AO classification, 13 fractures were type C3, 7 C2 and 1 A2. All patientes were operated on without desinsertion of the extensor mechanism. Average follow-up was 40 months. Results Flexo-extension was 123-17°, with a total arc of mobility of 106° (80 % of the contralateral side. Pain according to AVE was 1. The MEPI was 83 points: 8 patients had excellent results, 11 good, 1 regular and 1 bad. Average DASH score was 24 points. Conclusion Treatment of humeral distal fractures with total elbow arthoplasty in patients older than 65 years old, may lead to a good option of treatment, but indications must be limited to patients with complex fractures, bad bone quality, with osteoporosis and low functional demands.

Stress Fractures

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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 ...

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.

The Value of Laboratory Tests in Diagnosing Secondary Osteoporosis at a Fracture and Osteoporosis Outpatient Clinic

NARCIS (Netherlands)

de Klerk, Gijs; Hegeman, J. Han; van der Velde, Detlef; van der Palen, Jacobus Adrianus Maria; ten Duis, Henk J.

2013-01-01

Background: As more and more patients meeting the criteria for osteoporosis are referred to a fracture and osteoporosis outpatient clinic (FO clinic), the laboratory costs to screen for secondary osteoporosis also increases. This study was conducted to determine the value of screening on underlying

Fractures and alcohol abuse - patient opinion of alcohol intervention

DEFF Research Database (Denmark)

Pedersen, Bolette; Alva-Jørgensen, Peter; Raffing, Rie

2011-01-01

PURPOSE: To clarify patient opinions about alcohol intervention in relation to surgery before investigating the effect in a Scandinavian multi-centre randomized trial. MATERIAL AND METHODS: A qualitative study. Thirteen consecutive alcohol patients with fractures participated after informed consent....... They were interviewed during their hospital stay. The number of participants was based on the criteria of data-saturation. The analysis followed the applied qualitative framework model aimed at evaluation of specific participant needs within a larger overall project. RESULTS: All patients regarded alcohol...

Risk of hip fracture after osteoporosis fractures. 451 women with fracture of lumbar spine, olecranon, knee or ankle

DEFF Research Database (Denmark)

Lauritzen, J B; Lund, B

1993-01-01

In a follow-up study during 1976-1984, the risk of a subsequent hip fracture was investigated in women aged 60-99 years, hospitalized for the following fractures: lumbar spine (n 70), olecranon (n 52), knee (n 129) and ankle (n 200). Follow-up ranged from 0 to 9 years. Observation time of the 4...... different fractures were 241, 180, 469, and 779, person-years, respectively. In women aged 60-79 years with one of the following fractures the relative risk of a subsequent hip fracture was increased by 4.8 (lumbar spine), 4.1 (olecranon), 3.5 (knee) and 1.5 (ankle). The relative risk of hip fracture showed...... a tendency to level off 3 years after the primary fracture....

Damage evolution and failure mechanisms in additively manufactured stainless steel

Energy Technology Data Exchange (ETDEWEB)

Carlton, Holly D., E-mail: carlton4@llnl.gov [Materials Engineering Division, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Haboub, Abdel [Lincoln University, Life and Physical Sciences Department, 820 Chestnut St, Jefferson City, MO 65101 (United States); Gallegos, Gilbert F. [Materials Engineering Division, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Parkinson, Dilworth Y.; MacDowell, Alastair A. [Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)

2016-01-10

In situ tensile tests were performed on additively manufactured austenitic stainless steel to track damage evolution within the material. For these experiments Synchrotron Radiation micro-Tomography was used to measure three-dimensional pore volume, distribution, and morphology in stainless steel at the micrometer length-scale while tensile loading was applied. The results showed that porosity distribution played a larger role in affecting the fracture mechanisms than measured bulk density. Specifically, additively manufactured stainless steel specimens with large inhomogeneous void distributions displayed a flaw-dominated failure where cracks were shown to initiate at pre-existing voids, while annealed additively manufactured stainless steel specimens, which contained low porosity and randomly distributed pores, displayed fracture mechanisms that closely resembled wrought metal.

Feasibility of progressive strength training implemented in the acute ward after hip fracture surgery.

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Lise Kronborg

Full Text Available Patients with a hip fracture lose more than 50% knee-extension strength in the fractured limb within one week of surgery. Hence, immediate progressive strength training following hip fracture surgery may be rational, but the feasibility unknown.To examine the feasibility of in-hospital progressive strength training implemented in the acute ward following hip fracture surgery, based on pre-specified criteria for feasibility.A prospective cohort study conducted in an acute orthopedic hip fracture unit at a university hospital. A consecutive sample of 36 patients, 18 with a cervical and 18 with a trochanteric hip fracture (27 women and 9 men, mean (SD age of 79.4 (8.3 years were included between June and December 2012.A daily (on weekdays program of progressive knee-extension strength training for the fractured limb, using ankle weight cuffs in 3 sets of 10 repetition maximum loadings.The primary outcome was the change in training load (kg during the knee-extension strength training. The secondary outcomes were changes in hip fracture-related pain and maximal isometric knee-extension strength.The strength training was commenced at a mean of 2.4 (0.7 days after surgery. The training loads (kilograms lifted increased from 1.6 (0.8 to 4.3 (1.7 kg over 4.3 (2.2 training sessions (P<.001. The maximal isometric knee-extension strength of the fractured limb increased from 0.37 (0.2 to 0.61 (0.3 Nm/kg (P<.001, while the average strength deficit in the fractured limb decreased from 50% to 32% (% non-fractured, P<.001. Only 3 of 212 sessions were not performed because of severe hip fracture-related pain.Progressive knee-extension strength training of the fractured limb commenced in the acute ward seems feasible, and may reduce strength asymmetry between limbs without hip pain interfering. The clinical efficacy needs confirmation in a randomized controlled design.ClinicalTrials.gov ID: NCT01616030.

Paediatric tibial shaft fractures treated by open reduction and stabilization with monolateral external fixation.

Science.gov (United States)

Simon, A-L; Apostolou, N; Vidal, C; Ferrero, E; Mazda, K; Ilharreborde, B

2018-02-01

Elastic stable intramedullary nailing is increasingly used for surgical treatment of tibial shaft fractures, but frequently requires immobilization and delayed full weight-bearing. Therefore, external fixation remains interesting. The aim was to report clinico-radiological outcomes of monolateral external fixation for displaced and unstable tibial shaft fractures in children. All tibial fractures consecutively treated by monolateral external fixation between 2008 and 2013 were followed. Inclusion criteria included skeletal immaturity and closed and open Gustilo I fractures caused by a direct impact. Patients were seen until two years postoperatively. Demographics, mechanism of injury, surgical data and complications were recorded. Anteroposterior and lateral side radiographs were performed at each visit. Full-limb 3D reconstructions using biplanar stereroradiography was performed for final limb length and alignment measures. A total of 45 patients (mean age 9.7 years ± 0.5) were included. In all, 17 were Gustilo I fractures, with no difference between open and closed fractures for any data. Mean time to full weight bearing was 18.2 days ± 0.7. After 15 days, 39 patients returned to school. Hardware removal (mean time to union 15.6 weeks ± 0.8) was performed during consultation under analgesic gas. There were no cases of nonunion. No fracture healed with > 10° of angulation (mean 5.1° ± 0.4°). Leg-length discrepancy > 10 mm was found for six patients. This procedure can be a safe and simple surgical treatment for children with tibial shaft fractures. Few complications and early return to school were reported, with the limitations of non-comparative study. IV.

Angiographic frequency of blunt cerebrovascular injury in patients with carotid canal or vertebral foramen fractures on multidetector CT

International Nuclear Information System (INIS)

McKinney, Alexander; Ott, Frederick; Short, James; McKinney, Zeke; Truwit, Charles

2007-01-01

Purpose: Blunt carotid injuries (BCI's) and blunt vertebral artery injuries (BVI's), known jointly as BCVI's, are common in 'high risk' patients. The purpose is to evaluate the rate of occurrence of BCI/BVI in patients screened purely by the radiologic criteria of fracture through the carotid canal or vertebral transverse foramina, or significant cervical subluxation, noted by multidetector CT. Methods: Seventy-one patients with 108 catheterized vessels were included over a 13-month interval. The angiographic examinations were prompted by current hospital protocol, solely by the presence of fractures involving/adjacent to the carotid canal, cervical fractures involving/adjacent to the foramen transversarium, or cervical fractures with significant subluxation. The incidence of each grade of blunt injury was calculated after review of the CT scans and catheter angiograms by two neuroradiologists. Results: Two thousand and seventy-three total blunt trauma admissions occurred during the time period, with a BCVI rate of 0.92-1.0% (depending on the reviewer), similar to previous studies. Mean time to catheter angiography was 16.6 h. Of the 71 included patients, there were 11-12 BCI's and 10-12 BVI's, an overall rate of 27-30% of BCVI in the patients with foraminal fractures. Interobserver agreement in reviewing the catheter angiograms was excellent (Kappa 0.795). Of note, three internal carotid pseudoaneurysms resolved spontaneously after anticoagulation or aspirin. Conclusion: This study confirms that there is a high rate of BCVI in the presence of carotid canal or vertebral foramen fractures that are noted by multidetector CT. Utilization of purely radiologic criteria of foraminal involvement may be a significant screening tool in the decision of whether to evaluate these patients acutely by catheter or CT angiography, and for early detection of patients at risk for symptomatology, to initiate prompt, prophylactic treatment

Angiographic frequency of blunt cerebrovascular injury in patients with carotid canal or vertebral foramen fractures on multidetector CT

Energy Technology Data Exchange (ETDEWEB)

McKinney, Alexander [Department of Radiology, Hennepin County and University of Minnesota-Fairview and Medical Centers, Minneapolis, MN (United States)]. E-mail: mckin022@umn.edu; Ott, Frederick [Department of Radiology, Hennepin County and University of Minnesota-Fairview and Medical Centers, Minneapolis, MN (United States); Short, James [Department of Radiology, Hennepin County and University of Minnesota-Fairview and Medical Centers, Minneapolis, MN (United States); McKinney, Zeke [Department of Radiology, Hennepin County and University of Minnesota-Fairview and Medical Centers, Minneapolis, MN (United States); Truwit, Charles [Department of Radiology, Hennepin County and University of Minnesota-Fairview and Medical Centers, Minneapolis, MN (United States)

2007-06-15

Purpose: Blunt carotid injuries (BCI's) and blunt vertebral artery injuries (BVI's), known jointly as BCVI's, are common in 'high risk' patients. The purpose is to evaluate the rate of occurrence of BCI/BVI in patients screened purely by the radiologic criteria of fracture through the carotid canal or vertebral transverse foramina, or significant cervical subluxation, noted by multidetector CT. Methods: Seventy-one patients with 108 catheterized vessels were included over a 13-month interval. The angiographic examinations were prompted by current hospital protocol, solely by the presence of fractures involving/adjacent to the carotid canal, cervical fractures involving/adjacent to the foramen transversarium, or cervical fractures with significant subluxation. The incidence of each grade of blunt injury was calculated after review of the CT scans and catheter angiograms by two neuroradiologists. Results: Two thousand and seventy-three total blunt trauma admissions occurred during the time period, with a BCVI rate of 0.92-1.0% (depending on the reviewer), similar to previous studies. Mean time to catheter angiography was 16.6 h. Of the 71 included patients, there were 11-12 BCI's and 10-12 BVI's, an overall rate of 27-30% of BCVI in the patients with foraminal fractures. Interobserver agreement in reviewing the catheter angiograms was excellent (Kappa 0.795). Of note, three internal carotid pseudoaneurysms resolved spontaneously after anticoagulation or aspirin. Conclusion: This study confirms that there is a high rate of BCVI in the presence of carotid canal or vertebral foramen fractures that are noted by multidetector CT. Utilization of purely radiologic criteria of foraminal involvement may be a significant screening tool in the decision of whether to evaluate these patients acutely by catheter or CT angiography, and for early detection of patients at risk for symptomatology, to initiate prompt, prophylactic treatment.

Bone biology in the elderly: clinical importance for fracture treatment

Directory of Open Access Journals (Sweden)

Rolvien Tim

2016-12-01

Full Text Available Age-related bone impairment often leads to fragility fractures in the elderly. Although excellent surgical care is widely provided, diagnosis and treatment of the underlying bone disorder are often not kept in mind. The interplay of the three major bone cells – osteoblasts, osteoclasts, and osteocytes – is normally well regulated via the secretion of messengers to control bone remodeling. Possible imbalances that might occur in the elderly are partly due to age, genetic risk factors, and adverse lifestyle factors but importantly also due to imbalances in calcium homeostasis (mostly due to vitamin D deficiency or hypochlorhydria, which have to be eliminated. Therefore, the cooperation between the trauma surgeon and the osteologist is of major importance to diagnose and treat the respective patients at risk. We propose that any patient suffering from fragility fractures is rigorously screened for osteoporosis and metabolic bone diseases. This includes bone density measurement by dual-energy X-ray absorptiometry, laboratory tests for calcium, phosphate, vitamin D, and bone turnover markers, as well as additional diagnostic modalities if needed. Thereby, most risk factors, including vitamin D deficiency, can be identified and treated while patients who meet the criteria for a specific therapy (i.e. antiresorptive and osteoanabolic receive such. If local health systems succeed to manage this process of secondary fracture prevention, morbidity and mortality of fragility fractures will decline to a minimum level.

ASSOCIATION BETWEEN COMPUTED TOMOGRAPHIC CHARACTERISTICS AND FRACTURES FOLLOWING STEREOTACTIC RADIOSURGERY IN DOGS WITH APPENDICULAR OSTEOSARCOMA.

Science.gov (United States)

Kubicek, Lyndsay; Vanderhart, Daniel; Wirth, Kimberly; An, Qi; Chang, Myron; Farese, James; Bova, Francis; Sudhyadhom, Atchar; Kow, Kelvin; Bacon, Nicholas J; Milner, Rowan

2016-05-01

The objective of this observational, descriptive, retrospective study was to report CT characteristics associated with fractures following stereotactic radiosurgery in canine patients with appendicular osteosarcoma. Medical records (1999 and 2012) of dogs that had a diagnosis of appendicular osteosarcoma and undergone stereotactic radiosurgery were reviewed. Dogs were included in the study if they had undergone stereotactic radiosurgery for an aggressive bone lesion with follow-up information regarding fracture status, toxicity, and date and cause of death. Computed tomography details, staging, chemotherapy, toxicity, fracture status and survival data were recorded. Overall median survival time (MST) and fracture rates of treated dogs were calculated. CT characteristics were evaluated for association with time to fracture. Forty-six dogs met inclusion criteria. The median overall survival time was 9.7 months (95% CI: 6.9-14.3 months). The fracture-free rates at 3, 6, and 9 months were 73%, 44%, and 38% (95% CI: 60-86%, 29-60%, and 22-54%), respectively. The region of bone affected was significantly associated with time to fracture. The median time to fracture was 4.2 months in dogs with subchondral bone involvement and 16.3 months in dogs without subchondral bone involvement (P-value = 0.027, log-rank test). Acute and late skin effects were present in 58% and 16% of patients, respectively. Findings demonstrated a need for improved patient selection for this procedure, which can be aided by CT-based prognostic factors to predict the likelihood of fracture. © 2016 American College of Veterinary Radiology.

Non-metallic implant for patellar fracture fixation: A systematic review.

Science.gov (United States)

Camarda, Lawrence; Morello, Salvatore; Balistreri, Francesco; D'Arienzo, Antonio; D'Arienzo, Michele

2016-08-01

Despite good clinical outcome proposals, there has been relatively little published regarding the use of non-metallic implant for patellar fracture fixation. The purpose of the study was to perform a systematic literature review to summarize and evaluate the clinical studies that described techniques for treating patella fractures using non-metallic implants. A comprehensive literature search was systematically performed to evaluate all studies included in the literature until November 2015. The following search terms were used: patellar fracture, patella suture, patella absorbable, patella screw, patella cerclage. Two investigators independently reviewed all abstracts and the selection of these abstracts was then performed based on inclusion and/or exclusion criteria. A total of 9 studies involving 123 patients were included. Patients had a mean age of 33.7 years and were followed up for a mean of 18.9 months. The most common method for fracture fixations included the use of suture material. Good clinical outcomes were reported among all studies. Thirteen patients (10.5%) presented complications, while 4 patients (3.2%) required additional surgery for implant removal. There is a paucity of literature focused on the use of non-metallic implant for patellar fracture fixation. However, this systematic review showed that non-metallic implants are able to deliver good clinical outcomes reducing the rate of surgical complications and re-operation. These results may assist surgeons in choosing to use alternative material such as sutures to incorporate into their routine practice or to consider it, in order to reduce the rate of re-operation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rib and sternum fractures in the elderly and extreme elderly following motor vehicle crashes.

Science.gov (United States)

Bansal, Vishal; Conroy, Carol; Chang, David; Tominaga, Gail T; Coimbra, Raul

2011-05-01

As the population ages, the need to protect the elderly during motor vehicle crashes becomes increasingly critical. This study focuses on causation of elderly rib and sternum fractures in seriously injured elderly occupants involved in motor vehicle crashes. We used data from the Crash Injury Research and Engineering Network (CIREN) database (1997-2009). Study case criteria included occupant (≥ 65 years old) drivers (sitting in the left outboard position of the first row) or passengers (sitting in the first row right outboard position) who were in frontal or side impacts. To avoid selection bias, only occupants with a Maximum Abbreviated Injury Scale (MAIS) 3 (serious) or greater severity injury were included in this study. Odds ratios were used as a descriptive measure of the strength of association between variables and Chi square tests were used to determine if there was a statistically significant relationship between categorical variables. Of the 211 elderly (65-79 years old) occupants with thoracic injury, 92.0% had rib fractures and 19.6% had sternum fractures. For the 76 extreme elderly (80 years or older) with thoracic injury, 90.4% had rib fractures and 27.7% had sternum fractures. Except for greater mortality and more rib fractures caused by safety belts, there were no differences between the extreme elderly and the elderly occupants. Current safety systems may need to be redesigned to prevent rib and sternum fractures in occupants 80 years and older. Copyright © 2010 Elsevier Ltd. All rights reserved.

Paediatric diaphyseal femur fracture treated with intramedullary titanium elastic nail system

Directory of Open Access Journals (Sweden)

Shrawan Kumar Thapa

2015-11-01

Full Text Available noBackground & Objectives: Over the few years there has been a marked increase in the use of intramedullary fixation in the management of fracture of shaft of femur in children. The goals should be to stabilize the fracture, to control length and alignment, to promote bone healing and to minimize the morbidity and complications for the child. In this prospective study we intend to evaluate the functional and radiological outcome of diaphyseal fracture of shaft of femur treated with elastic intramedullary nail.Materials & Methods: All 56 patients with diaphyseal fracture shaft of femur were treated with titanium elastic nail and followed for period of 32 weeks.Results: The In this study, outcome was assessed by using Flynn’s criteria of titanium flexible nail outcome score and we found excellent result in 49 cases, satisfactory in six cases and poor in one case. We faced one major complication in form of implant failure and six minor complications inform of superficial wound infection.Conclusion: Elastic intramedullary nail used in treatment of diaphyseal fracture shaft of femur yield excellent functional and radiological outcome. It is easy and simple procedure has low rate of complication. It is physeal-protective, cost effective, does not involve heavy instrumentation and can be performed in small set up. It has minimal risk of infection and no risk of injury to the neurovascular structure.JCMS Nepal. 2015; 11(2:20-22

Rapid expansion and fracture of metallic cylinders driven by explosive loads

International Nuclear Information System (INIS)

Hiroe, T.; Fujiwara, K.; Abe, T.; Yoshida, M.

2004-01-01

Smooth walled tubular specimens of stainless steel and low-carbon steels were explosively expanded to fragmentation. The driver was a column of the high explosive PETN inserted into the central bore and initiated by exploding a fine copper wire using a discharge current from a high-voltage capacitor bank. The variation of wall thickness and the effect of different explosive driver diameters are reported. A fully charged casing model was also exploded with initiation at the end surface for comparison. Streak and framing photos show both radially and axially symmetric expansion of cylinders at average strain rates of above 104 s-1 and a wall velocity of 417-1550 m/s. Some framing photos indicate the initiation and spacing of fractures during the bursting of the cylinders. Hydro codes have been applied to simulate the experimental behavior of the cylinders, examining numerical stresses, deformation and fracture criteria. Most of the fragments were successfully recovered inside a cushion-filled chamber, and the circumferential fracture spacing of measured fragments is investigated using a fragmentation model

High prevalence of simultaneous rib and vertebral fractures in patients with hip fracture.

Science.gov (United States)

Lee, Bong-Gun; Sung, Yoon-Kyoung; Kim, Dam; Choi, Yun Young; Kim, Hunchul; Kim, Yeesuk

2017-02-01

The purpose was to evaluate the prevalence and location of simultaneous fracture using bone scans in patients with hip fracture and to determine the risk factors associated with simultaneous fracture. One hundred eighty two patients with hip fracture were reviewed for this study. Clinical parameters and bone mineral density (BMD) of the lumbar vertebra and femoral neck were investigated. To identify acute simultaneous fracture, a bone scan was performed at 15.4±4.1days after hip fracture. The prevalence and location of simultaneous fracture were evaluated, and multivariate logistic regression analysis was performed to determine the risk factors. Simultaneous fracture was observed in 102 of 182 patients, a prevalence of 56.0%. Rib fracture was the most common type of simultaneous fracture followed by rib with vertebral fracture. The BMD of the lumbar vertebra was significantly lower in patients with simultaneous fracture (p=0.044) and was identified as an independent risk factor (odds ratio: OR 0.05, 95% confidence interval: CI 0.01-0.57). The prevalence of simultaneous fracture was relatively high among patients with hip fracture, and BMD was significantly lower in patients with simultaneous fracture than in patients without it. Surgeons should be aware of the possibility of simultaneous fracture in patients with hip fracture. Copyright © 2016 Elsevier Ltd. All rights reserved.

External fixation of tibial pilon fractures and fracture healing.

Science.gov (United States)

Ristiniemi, Jukka

2007-06-01

Distal tibial fractures are rare and difficult to treat because the bones are subcutaneous. External fixation is commonly used, but the method often results in delayed union. The aim of the present study was to find out the factors that affect fracture union in tibial pilon fractures. For this purpose, prospective data collection of tibial pilon fractures was carried out in 1998-2004, resulting in 159 fractures, of which 83 were treated with external fixation. Additionally, 23 open tibial fractures with significant > 3 cm bone defect that were treated with a staged method in 2000-2004 were retrospectively evaluated. The specific questions to be answered were: What are the risk factors for delayed union associated with two-ring hybrid external fixation? Does human recombinant BMP-7 accelerate healing? What is the role of temporary ankle-spanning external fixation? What is the healing potential of distal tibial bone loss treated with a staged method using antibiotic beads and subsequent autogenous cancellous grafting compared to other locations of the tibia? The following risk factors for delayed healing after external fixation were identified: post-reduction fracture gap of >3 mm and fixation of the associated fibula fracture. Fracture displacement could be better controlled with initial temporary external fixation than with early definitive fixation, but it had no significant effect on healing time, functional outcome or complication rate. Osteoinduction with rhBMP-7 was found to accelerate fracture healing and to shorten the sick leave. A staged method using antibiotic beads and subsequent autogenous cancellous grafting proved to be effective in the treatment of tibial bone loss. Healing potential of the bone loss in distal tibia was at least equally good as in other locations of the tibia.

Radiographic anatomy of the proximal femur: femoral neck fracture vs. transtrochanteric fracture

Directory of Open Access Journals (Sweden)

Ana Lecia Carneiro Leão de Araújo Lima

Full Text Available ABSTRACT OBJECTIVE: To evaluate the correlation between radiographic parameters of the proximal femur with femoral neck fractures or transtrochanteric fractures. METHODS: Cervicodiaphyseal angle (CDA, femoral neck width (FNW, hip axis length (HAL, and acetabular tear drop distance (ATD were analyzed in 30 pelvis anteroposterior view X-rays of patients with femoral neck fractures (n = 15 and transtrochanteric fractures (n = 15. The analysis was performed by comparing the results of the X-rays with femoral neck fractures and with transtrochanteric fractures. RESULTS: No statistically significant differences between samples were observed. CONCLUSION: There was no correlation between radiographic parameters evaluated and specific occurrence of femoral neck fractures or transtrochanteric fractures.

Prior nonhip limb fracture predicts subsequent hip fracture in institutionalized elderly people.

Science.gov (United States)

Nakamura, K; Takahashi, S; Oyama, M; Oshiki, R; Kobayashi, R; Saito, T; Yoshizawa, Y; Tsuchiya, Y

2010-08-01

This 1-year cohort study of nursing home residents revealed that historical fractures of upper limbs or nonhip lower limbs were associated with hip fracture (hazard ratio = 2.14), independent of activities of daily living (ADL), mobility, dementia, weight, and type of nursing home. Prior nonhip fractures are useful for predicting of hip fracture in institutional settings. The aim of this study was to evaluate the utility of fracture history for the prediction of hip fracture in nursing home residents. This was a cohort study with a 1-year follow-up. Subjects were 8,905 residents of nursing homes in Niigata, Japan (mean age, 84.3 years). Fracture histories were obtained from nursing home medical records. ADL levels were assessed by caregivers. Hip fracture diagnosis was based on hospital medical records. Subjects had fracture histories of upper limbs (5.0%), hip (14.0%), and nonhip lower limbs (4.6%). Among historical single fractures, only prior nonhip lower limbs significantly predicted subsequent fracture (adjusted hazard ratio, 2.43; 95% confidence interval (CI), 1.30-4.57). The stepwise method selected the best model, in which a combined historical fracture at upper limbs or nonhip lower limbs (adjusted hazard ratio, 2.14; 95% CI, 1.30-3.52), dependence, ADL levels, mobility, dementia, weight, and type of nursing home independently predicted subsequent hip fracture. A fracture history at upper or nonhip lower limbs, in combination with other known risk factors, is useful for the prediction of future hip fracture in institutional settings.

Mandible Fractures.

Science.gov (United States)

Pickrell, Brent B; Serebrakian, Arman T; Maricevich, Renata S

2017-05-01

Mandible fractures account for a significant portion of maxillofacial injuries and the evaluation, diagnosis, and management of these fractures remain challenging despite improved imaging technology and fixation techniques. Understanding appropriate surgical management can prevent complications such as malocclusion, pain, and revision procedures. Depending on the type and location of the fractures, various open and closed surgical reduction techniques can be utilized. In this article, the authors review the diagnostic evaluation, treatment options, and common complications of mandible fractures. Special considerations are described for pediatric and atrophic mandibles.

Recognizing and reporting vertebral fractures: reducing the risk of future osteoporotic fractures

International Nuclear Information System (INIS)

Lentle, B.C.; Brown, J.P.; Khan, A.

2007-01-01

Given the increasing evidence that vertebral fractures are underdiagnosed and not acted on, Osteoporosis Canada and the Canadian Association of Radiologists initiated a project to develop and publish a set of recommendations to promote and facilitate the diagnosis and reporting of vertebral fractures. The identification of spinal fractures is not uniform. More than 65% of vertebral fractures cause no symptoms. It is also apparent that vertebral fractures are inadequately recognized when the opportunity for diagnosis arises fortuitously. It is to patients' benefit that radiologists report vertebral fractures evident on a chest or other radiograph, no matter how incidental to the immediate clinical indication for the examination. The present recommendations can help to close the gap in care in recognizing and treating vertebral fractures, to prevent future fractures and thus reduce the burden of osteoporosis-related morbidity and mortality, as well as fracture-related costs to the health care system. Several studies indicate that a gap exists in regard to the diagnosis of vertebral fractures and the clinical response following such diagnosis. All recommendations presented here are based on consensus. These recommendations were developed by a multidisciplinary working group under the auspices of the Scientific Advisory Council of Osteoporosis Canada and the Canadian Association of Radiologists. Prevalent vertebral fractures have important clinical implications in terms of future fracture risk. Recognizing and reporting fractures incidental to radiologic examinations done for other reasons has the potential to reduce health care costs by initiating further steps in osteoporosis diagnosis and appropriate therapy. Physicians should be aware of the importance of vertebral fracture diagnosis in assessing future osteoporotic fracture risk. Vertebral fractures incidental to radiologic examinations done for other reasons should be identified and reported. Vertebral fractures

Long-term patient outcomes after surgical stabilization of rib fractures.

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Majercik, Sarah; Cannon, Quinn; Granger, Steven R; VanBoerum, Don H; White, Thomas W

2014-07-01

Rib fractures are common, and can be disabling. Recently, there has been increased interest in surgical stabilization of rib fractures (SSRF). It is difficult to define long-term benefits of the procedure. This is a descriptive study of patient outcomes after SSRF. SSRF patients between April 2010 and August 2012 at a Level I trauma center were identified. Data were collected from the medical records. A telephone survey asking about pain, satisfaction, and employment was administered to patients after hospital discharge. One hundred-one patients met inclusion criteria. Fifty (50%) patients completed the survey. Indications for SSRF included flail chest, displaced fractures, pain, and inability to wean from mechanical ventilation. Pain was gone at 5.4 ± 1.1 weeks post discharge. Satisfaction with SSRF on a scale of 1 to 10 was 9.2 ± .2. Ninety percent of employed patients returned to the same work at 8.5 ± 1.2 weeks. SSRF patients are satisfied and are able to return to normal activity with few limitations. A prospective study using modern rib fixation technology is needed to further define benefits. Copyright © 2014 Elsevier Inc. All rights reserved.

[Establishment of Schatzker classification digital models of tibial plateau fractures and its application on virtual surgery].

Science.gov (United States)

Liu, Yong-gang; Zuo, Li-xin; Pei, Guo-xian; Dai, Ke; Sang, Jing-wei

2013-08-20

To explore the establishment of Schatzker classification digital model of tibial plateau fractures and its application in virtual surgery. Proximal tibial of one healthy male volunteer was examined with 64-slice spiral computed tomography (CT). The data were processed by software Mimics 10.01 and a model of proximal tibia was reconstructed. According to the Schatzker classification criteria of tibial plateau fractures, each type of fracture model was simulated.Screen-captures of fracture model were saved from different directions.Each type of fracture model was exported as video mode.Fracture model was imported into FreeForm modeling system.With a force feedback device, a surgeon could conduct virtual fracture operation simulation.Utilizing the GHOST of FreeForm modeling system, the software of virtual cutting, fracture reduction and fixation was developed.With a force feedback device PHANTOM, a surgeon could manipulate virtual surgical instruments and fracture classification model and simulate surgical actions such as assembly of surgical instruments, drilling, implantation of screw, reduction of fracture, bone grafting and fracture fixation, etc. The digital fracture model was intuitive, three-dimensional and realistic and it had excellent visual effect.Fracture could be observed and charted from optional direction and angle.Fracture model could rotate 360 ° in the corresponding video mode. The virtual surgical environment had a strong sense of reality, immersion and telepresence as well as good interaction and force feedback function in the FreeForm modeling system. The user could make the corresponding decisions about surgical method and choice of internal fixation according to the specific type of tibial plateau fracture as well as repeated operational practice in virtual surgery system. The digital fracture model of Schatzker classification is intuitive, three-dimensional, realistic and dynamic. The virtual surgery systems of Schatzker classifications make

External skeletal fixator intramedullary pin tie-in for the repair of tibiotarsal fractures in raptors: 37 cases (1995-2011).

Science.gov (United States)

Bueno, Irene; Redig, Patrick T; Rendahl, Aaron K

2015-11-15

To evaluate the outcome of the application of an external skeletal fixator intramedullary pin tie-in (TIF) to tibiotarsal fractures in raptors. Retrospective case series. Thirty-four raptors with 37 tibiotarsal fractures. Medical records and radiographs for raptors with tibiotarsal fractures that were treated at The Raptor Center at the University of Minnesota between 1995 and 2011 were reviewed. Descriptive statistics were generated and univariate logistic regression analyses were used to assess whether age, sex, body weight, location and nature of the fracture, and type of surgical reduction were significantly associated with whether the fracture healed following surgical reduction and TIF application. 31 of 37 (84%) tibiotarsal fractures successfully healed following surgical reduction and TIF application. The mean healing time was 38 days (range, 15 to 70 days). None of the variables assessed were significantly associated with whether the tibiotarsal fracture healed. Twenty of the 34 (59%) raptors were eventually rehabilitated and released. Results indicated that most tibiotarsal fractures were successfully managed by surgical reduction and stabilization with a TIF. However, other comorbidities (eg, systemic infections and visual deficits) negatively affected the rehabilitation of raptors and sometimes resulted in euthanasia despite the fact that the tibiotarsal fracture had healed, and those comorbidities, along with the variables evaluated (eg, age, sex, and nature of the fracture), should be used as triage criteria and prognostic indicators.

Crack initiation criteria for singular stress concentrations Part I: A universal assessment of singular stress concentrations

Czech Academy of Sciences Publication Activity Database

Knésl, Zdeněk; Klusák, Jan; Náhlík, Luboš

2007-01-01

Roč. 14, č. 6 (2007), s. 399-408 ISSN 1802-1484 R&D Projects: GA ČR(CZ) GA101/05/0320; GA ČR GA101/05/0227 Institutional research plan: CEZ:AV0Z20410507 Keywords : fracture mechanics * stability criteria * singular stress concentrations * crack initiation * critical stress Subject RIV: JL - Materials Fatigue, Friction Mechanics

Simulation of complex fracture networks influenced by natural fractures in shale gas reservoir

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Zhao Jinzhou

2014-10-01

Full Text Available When hydraulic fractures intersect with natural fractures, the geometry and complexity of a fracture network are determined by the initiation and propagation pattern which is affected by a number of factors. Based on the fracture mechanics, the criterion for initiation and propagation of a fracture was introduced to analyze the tendency of a propagating angle and factors affecting propagating pressure. On this basis, a mathematic model with a complex fracture network was established to investigate how the fracture network form changes with different parameters, including rock mechanics, in-situ stress distribution, fracture properties, and frac treatment parameters. The solving process of this model was accelerated by classifying the calculation nodes on the extending direction of the fracture by equal pressure gradients, and solving the geometrical parameters prior to the iteration fitting flow distribution. With the initiation and propagation criterion as the bases for the propagation of branch fractures, this method decreased the iteration times through eliminating the fitting of the fracture length in conventional 3D fracture simulation. The simulation results indicated that the formation with abundant natural fractures and smaller in-situ stress difference is sufficient conditions for fracture network development. If the pressure in the hydraulic fractures can be kept at a high level by temporary sealing or diversion, the branch fractures will propagate further with minor curvature radius, thus enlarging the reservoir stimulation area. The simulated shape of fracture network can be well matched with the field microseismic mapping in data point range and distribution density, validating the accuracy of this model.

Simulation of quasi-static hydraulic fracture propagation in porous media with XFEM

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Juan-Lien Ramirez, Alina; Neuweiler, Insa; Löhnert, Stefan

2015-04-01

Hydraulic fracturing is the injection of a fracking fluid at high pressures into the underground. Its goal is to create and expand fracture networks to increase the rock permeability. It is a technique used, for example, for oil and gas recovery and for geothermal energy extraction, since higher rock permeability improves production. Many physical processes take place when it comes to fracking; rock deformation, fluid flow within the fractures, as well as into and through the porous rock. All these processes are strongly coupled, what makes its numerical simulation rather challenging. We present a 2D numerical model that simulates the hydraulic propagation of an embedded fracture quasi-statically in a poroelastic, fully saturated material. Fluid flow within the porous rock is described by Darcy's law and the flow within the fracture is approximated by a parallel plate model. Additionally, the effect of leak-off is taken into consideration. The solid component of the porous medium is assumed to be linear elastic and the propagation criteria are given by the energy release rate and the stress intensity factors [1]. The used numerical method for the spatial discretization is the eXtended Finite Element Method (XFEM) [2]. It is based on the standard Finite Element Method, but introduces additional degrees of freedom and enrichment functions to describe discontinuities locally in a system. Through them the geometry of the discontinuity (e.g. a fracture) becomes independent of the mesh allowing it to move freely through the domain without a mesh-adapting step. With this numerical model we are able to simulate hydraulic fracture propagation with different initial fracture geometries and material parameters. Results from these simulations will also be presented. References [1] D. Gross and T. Seelig. Fracture Mechanics with an Introduction to Micromechanics. Springer, 2nd edition, (2011) [2] T. Belytschko and T. Black. Elastic crack growth in finite elements with minimal

Diagnostic accuracy of history, physical examination, and bedside ultrasound for diagnosis of extremity fractures in the emergency department: a systematic review.

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Joshi, Nikita; Lira, Alena; Mehta, Ninfa; Paladino, Lorenzo; Sinert, Richard

2013-01-01

Understanding history, physical examination, and ultrasonography (US) to diagnose extremity fractures compared with radiography has potential benefits of decreasing radiation exposure, costs, and pain and improving emergency department (ED) resource management and triage time. The authors performed two electronic searches using PubMed and EMBASE databases for studies published between 1965 to 2012 using a strategy based on the inclusion of any patient presenting with extremity injuries suspicious for fracture who had history and physical examination and a separate search for US performed by an emergency physician (EP) with subsequent radiography. The primary outcome was operating characteristics of ED history, physical examination, and US in diagnosing radiologically proven extremity fractures. The methodologic quality of the studies was assessed using the quality assessment of studies of diagnostic accuracy tool (QUADAS-2). Nine studies met the inclusion criteria for history and physical examination, while eight studies met the inclusion criteria for US. There was significant heterogeneity in the studies that prevented data pooling. Data were organized into subgroups based on anatomic fracture locations, but heterogeneity within the subgroups also prevented data pooling. The prevalence of fracture varied among the studies from 22% to 70%. Upper extremity physical examination tests have positive likelihood ratios (LRs) ranging from 1.2 to infinity and negative LRs ranging from 0 to 0.8. US sensitivities varied between 85% and 100%, specificities varied between 73% and 100%, positive LRs varied between 3.2 and 56.1, and negative LRs varied between 0 and 0.2. Compared with radiography, EP US is an accurate diagnostic test to rule in or rule out extremity fractures. The diagnostic accuracy for history and physical examination are inconclusive. Future research is needed to understand the accuracy of ED US when combined with history and physical examination for upper

Ductile crack initiation and propagation assessed via in situ synchrotron radiation-computed laminography

International Nuclear Information System (INIS)

Morgeneyer, T.F.; Helfen, L.; Sinclair, I.; Proudhon, H.; Xu, F.; Baumbach, T.

2011-01-01

Ductile crack initiation and propagation within a naturally aged aluminium alloy sheet has been observed in situ via synchrotron radiation-computed laminography, a technique specifically adapted to three-dimensional imaging of thin objects that are laterally extended. Voids and intermetallic particles, and their subsequent evolution during ductile crack extension at different associated levels of stress triaxiality, were clearly observed within fracture coupons of a reasonable engineering length-scale, overcoming the conventional sample size limitation of computed tomography at high resolutions.

Radiotherapy of pathologic fractures and skeletal lesions bearing the risk of fracture

International Nuclear Information System (INIS)

Rieden, K.; Kober, B.; Mende, U.; Zum Winkel, K.

1986-01-01

Radiotherapy is of great importance in the treatment of pathologic fractures and skeletal lesions bearing the risk of fracture which are induced by malignomas, especially if these are in an advanced stage. In dependence on site and extent of skeletal destruction as well as on the general tumor dissemination, it can be distinguished between palliative radiotherapy and curative radiotherapy aiming at analgesia and remineralization. A retrospective analysis of 27 pathologic fractures and 56 skeletal lesions bearing the risk of fracture in malignoma patients showed an analgetic effect obtained by radiotherapy in 67% of pathological fractures and in 80% of skeletal lesions bearing the risk of fracture, whereas a remineralization could be demonstrated for 33% of pathological fractures and 50% of destructions bearing the risk of fracture. A stabilization of destructions progressing before therapy was found in 55% of pathological fractures and 40% of skeletal lesions bearing the risk of fracture. Thus a partial loading, supported by orthopedic prostheses, was possible for more than 50% of all patients. (orig.) [de

[Trochanteric femoral fractures].

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Douša, P; Čech, O; Weissinger, M; Džupa, V

2013-01-01

At the present time proximal femoral fractures account for 30% of all fractures referred to hospitals for treatment. Our population is ageing, the proportion of patients with post-menopausal or senile osteoporosis is increasing and therefore the number of proximal femoral fractures requiring urgent treatment is growing too. In the age category of 50 years and older, the incidence of these fractures has increased exponentially. Our department serves as a trauma centre for half of Prague and part of the Central Bohemia Region with a population of 1 150 000. Prague in particular has a high number of elderly citizens. Our experience is based on extensive clinical data obtained from the Register of Proximal Femoral Fractures established in 1997. During 14 years, 4280 patients, 3112 women and 1168 men, were admitted to our department for treatment of proximal femoral fractures. All patients were followed up until healing or development of complications. In the group under study, 82% were patients older than 70 years; 72% of those requiring surgery were in their seventies and eighties. Men were significantly younger than women (pfractures were 2.3-times more frequent in women than in men. In the category under 60 years, men significantly outnumbered women (pfractures were, on the average, eight years older than the patients with intertrochanteric fractures, which is a significant difference (pTrochanteric fractures accounted for 54.7% and femoral neck fractures for 45.3% of all fractures. The inter-annual increase was 5.9%, with more trochanteric than femoral neck fractures. There was a non-significant decrease in intertrochanteric (AO 31-A3) fractures. On the other hand, the number of pertrochanteric (AO 31-A1+2) fractures increased significantly (pfractures were treated with a proximal femoral nail; a short nail was used in 1260 and a long nail in 134 of them. A dynamic hip screw (DHS) was employed to treat 947 fractures. Distinguishing between pertrochanteric (21-A1

Jogger's fracture and other stress fractures of the lumbo-sacral spine

International Nuclear Information System (INIS)

Abel, M.S.

1985-01-01

The posterior rings of the lower lumbo-sacral vertebrae are subject to stress fractures at any part - pedicle, pars, or lamina. The site of fracture is apparently determined by the axis of weight bearing. The three illustrative clinical examples cited include a jogger with a laminar fracture, a ballet dancer with pedicle fractures, and a nine-year-old boy with fractures of pars and lamina. Chronic low back pain is the typical complaint with stress fractures of the lower lumbo-sacral spine. Special imaging techniques are usually needed to demonstrate these lesions, including vertebral arch views, multi-directional tomography, and computed tomography (CT). (orig.)

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.

Influence of structures on fracture and fracture toughness of cemented tungsten carbides

International Nuclear Information System (INIS)

Zhao, W.; Zhang, X.

1987-01-01

A study was made of the influence of structures on fracture and fracture toughness of cemented tungsten carbides with different compositions and grain sizes. The measurement of the fracture toughness of cemented tungsten carbide was carried out using single edge notched beam. The microstructural parameters and the proportion for each fracture mode on the fracture surface were obtained. The brittle fracture of the alloy is mainly due to the interfacial decohesion fracture following the interface of the carbide crystals. It has been observed that there are localized fractures region ahead of the crack tip. The morphology of the crack propagation path as well as the slip structure in the cobalt phase of the deformed region have been investigated. In addition, a study of the correlation between the plane strain fracture toughness and microstructural parameters, such as mean free path of the cobalt phase, tungsten carbide grain size and the contiguity of tungsten carbide crystals was also made

Paediatric tibial shaft fractures treated by open reduction and stabilization with monolateral external fixation

Science.gov (United States)

Simon, A.-L.; Apostolou, N.; Vidal, C.; Ferrero, E.; Mazda, K.; Ilharreborde, B.

2018-01-01

Abstract Purpose Elastic stable intramedullary nailing is increasingly used for surgical treatment of tibial shaft fractures, but frequently requires immobilization and delayed full weight-bearing. Therefore, external fixation remains interesting. The aim was to report clinico-radiological outcomes of monolateral external fixation for displaced and unstable tibial shaft fractures in children. Methods All tibial fractures consecutively treated by monolateral external fixation between 2008 and 2013 were followed. Inclusion criteria included skeletal immaturity and closed and open Gustilo I fractures caused by a direct impact. Patients were seen until two years postoperatively. Demographics, mechanism of injury, surgical data and complications were recorded. Anteroposterior and lateral side radiographs were performed at each visit. Full-limb 3D reconstructions using biplanar stereroradiography was performed for final limb length and alignment measures. Results A total of 45 patients (mean age 9.7 years ± 0.5) were included. In all, 17 were Gustilo I fractures, with no difference between open and closed fractures for any data. Mean time to full weight bearing was 18.2 days ± 0.7. After 15 days, 39 patients returned to school. Hardware removal (mean time to union 15.6 weeks ± 0.8) was performed during consultation under analgesic gas. There were no cases of nonunion. No fracture healed with > 10° of angulation (mean 5.1° ± 0.4°). Leg-length discrepancy > 10 mm was found for six patients. Conclusions This procedure can be a safe and simple surgical treatment for children with tibial shaft fractures. Few complications and early return to school were reported, with the limitations of non-comparative study. Level of Evidence IV PMID:29456750

Outcomes of The Isolated Closed Tibial Shaft Fractures Treated Nonsurgically

Directory of Open Access Journals (Sweden)

Dawood Jafari

2011-05-01

selecting patients satisfying restricted criteria.Moreover,considering long-term physical disability with longer follow-up period, it seems that there still is a controversy in the treatment selection even for the simple tibial fractures.  

Rib fractures predict incident limb fractures: results from the European prospective osteoporosis study.

Science.gov (United States)

Ismail, A A; Silman, A J; Reeve, J; Kaptoge, S; O'Neill, T W

2006-01-01

Population studies suggest that rib fractures are associated with a reduction in bone mass. While much is known about the predictive risk of hip, spine and distal forearm fracture on the risk of future fracture, little is known about the impact of rib fracture. The aim of this study was to determine whether a recalled history of rib fracture was associated with an increased risk of future limb fracture. Men and women aged 50 years and over were recruited from population registers in 31 European centres for participation in a screening survey of osteoporosis (European Prospective Osteoporosis Study). Subjects were invited to complete an interviewer-administered questionnaire that included questions about previous fractures including rib fracture, the age of their first fracture and also the level of trauma. Lateral spine radiographs were performed and the presence of vertebral deformity was determined morphometrically. Following the baseline survey, subjects were followed prospectively by annual postal questionnaire to determine the occurrence of clinical fractures. The subjects included 6,344 men, with a mean age of 64.2 years, and 6,788 women, with a mean age of 63.6 years, who were followed for a median of 3 years (range 0.4-5.9 years), of whom 135 men (2.3%) and 101 women (1.6%) reported a previous low trauma rib fracture. In total, 138 men and 391 women sustained a limb fracture during follow-up. In women, after age adjustment, those with a recalled history of low trauma rib fracture had an increased risk of sustaining 'any' limb fracture [relative hazard (RH)=2.3; 95% CI 1.3, 4.0]. When stratified by fracture type the predictive risk was more marked for hip (RH=7.7; 95% CI 2.3, 25.9) and humerus fracture (RH=4.5; 95% CI 1.4, 14.6) than other sites (RH=1.6; 95% CI 0.6, 4.3). Additional adjustment for prevalent vertebral deformity and previous (non-rib) low trauma fractures at other sites slightly reduced the strength of the association between rib fracture and

Hip fracture - discharge

Science.gov (United States)

... neck fracture repair - discharge; Trochanteric fracture repair - discharge; Hip pinning surgery - discharge ... in the hospital for surgery to repair a hip fracture, a break in the upper part of ...

Quantifying Discrete Fracture Network Connectivity in Hydraulic Fracturing Stimulation

Science.gov (United States)

Urbancic, T.; Ardakani, E. P.; Baig, A.

2017-12-01

Hydraulic fracture stimulations generally result in microseismicity that is associated with the activation or extension of pre-existing microfractures and discontinuities. Microseismic events acquired under 3D downhole sensor coverage provide accurate event locations outlining hydraulic fracture growth. Combined with source characteristics, these events provide a high quality input for seismic moment tensor inversion and eventually constructing the representative discrete fracture network (DFN). In this study, we investigate the strain and stress state, identified fracture orientation, and DFN connectivity and performance for example stages in a multistage perf and plug completion in a North American shale play. We use topology, the familiar concept in many areas of structural geology, to further describe the relationships between the activated fractures and their effectiveness in enhancing permeability. We explore how local perturbations of stress state lead to the activation of different fractures sets and how that effects the DFN interaction and complexity. In particular, we observe that a more heterogeneous stress state shows a higher percentage of sub-horizontal fractures or bedding plane slips. Based on topology, the fractures are evenly distributed from the injection point, with decreasing numbers of connections by distance. The dimensionless measure of connection per branch and connection per line are used for quantifying the DFN connectivity. In order to connect the concept of connectivity back to productive volume and stimulation efficiency, the connectivity is compared with the character of deformation in the reservoir as deduced from the collective behavior of microseismicity using robustly determined source parameters.

Strategy for prevention of hip fractures in patients with Parkinson's disease.

Science.gov (United States)

Iwamoto, Jun; Sato, Yoshihiro; Takeda, Tsuyoshi; Matsumoto, Hideo

2012-09-18

Hypovitaminosis D and K due to malnutrition or sunlight deprivation, increased bone resorption due to immobilization, low bone mineral density (BMD) and an increased risk of falls may contribute to an increased risk of hip fractures in patients with Parkinson's disease. The purpose of the present study was to clarify the efficacy of interventions intended to prevent hip fractures in elderly patients with Parkinson's disease. PubMed was used to search the literature for randomized controlled trials (RCTs) regarding Parkinson's disease and hip fractures. The inclusion criteria were 50 or more subjects per group and a study period of 1 year or longer. Five RCTs were identified and the relative risk and 95% confidence interval were calculated for individual RCTs. Sunlight exposure increased serum hydroxyvitamin D [25(OH)D] concentration, improved motor function, decreased bone resorption and increased BMD. Alendronate or risedronate with vitamin D supplementation increased serum 25(OH)D concentration, strongly decreased bone resorption and increased BMD. Menatetrenone (vitamin K(2)) decreased serum undercarboxylated osteocalcin concentration, decreased bone resorption and increased BMD. Sunlight exposure (men and women), menatetrenone (women), alendronate and risedronate with vitamin D supplementation (women) significantly reduced the incidence of hip fractures. The respective RRs (95% confidence intervals) according to the intention-to-treat analysis were 0.27 (0.08, 0.96), 0.13 (0.02, 0.97), 0.29 (0.10, 0.85) and 0.20 (0.06, 0.68). Interventions, including sunlight exposure, menatetrenone and oral bisphosphonates with vitamin D supplementation, have a protective effect against hip fractures elderly patients with Parkinson's disease.

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

Can paramedics use FRAX (the WHO Fracture Risk Assessment Tool) to help GPs improve future fracture risk in patients who fall? Protocol for a randomised controlled feasibility study.

Science.gov (United States)

Clarke, Shane; Bradley, Rachel; Simmonds, Bethany; Salisbury, Chris; Benger, Jonathan; Marques, Elsa; Greenwood, Rosemary; Shepstone, Lee; Robinson, Maria; Appleby-Fleming, John; Gooberman-Hill, Rachael

2014-09-03

Currently identification, and therefore, management of patients at risk of osteoporotic fracture in the UK is suboptimal. As the majority of patients who fracture have fallen, it follows that people who fall can usefully be targeted in any programme that aims to reduce osteoporotic fracture. Targeting vulnerable patients who are likely to benefit from intervention may help shift the management of fracture prevention into primary care, away from emergency departments. Paramedics who attend to patients who have fallen may be well placed to assess future fracture risk, using the Fracture Risk Assessment Tool (FRAX) and communicate that information directly to general practitioners (GPs). This feasibility study takes the form of a pragmatic, randomised controlled trial aimed at exploring and refining issues of study design, recruitment, retention, sample size and acceptability preceding a large-scale study with fracture as the end point. Patients (aged >50) who fall, call an ambulance, are attended by a study paramedic and give verbal consent will be asked FRAX and fall questions. Patients who subsequently formally consent to participation will be randomised to control (usual care) or intervention groups. Intervention will constitute transmission of calculated future fracture risk to the patients' GP with suitable, evidence-based recommendations for investigation or treatment. 3 months after the index fall, data (proportion of patients in each group undergoing investigation or starting new treatment, quality of life and health economic) will be collected and analysed using descriptive statistics. A nested qualitative study will explore issues of acceptability and study design with patients, paramedics and GPs. This protocol was approved by NRES Committee South Central Oxford C in October 2012. Research Ethics Committee ref.12/SC/0604. The study findings will be disseminated through peer-reviewed journals, conference presentations and local public events. A publication

Does formal education and training of staff reduce the operation rate for fractures of the distal radius?

Science.gov (United States)

McDonald, Kyle; Murphy, Lynn; Gallagher, Brendan; Eames, Niall

2013-12-01

Fractures of the distal radius are one of the most common extremity fractures, and operation rates are increasing. Staff within our unit felt that formal teaching, particularly of new medical staff, with regards to fracture reduction and appropriate cast application could result in a reduction in operation rates. Retrospective data was extracted from FORD (Fracture Outcome and Research Database), including: number of fractures, number of fractures undergoing ORIF, fracture configuration, patient demographics, and mechanism of injury. All patients undergoing ORIF had their radiographs assessed by two separate reviewers. Information regarding adequate fracture reduction, adequate cast application (using Gap Index), and appropriate plaster cast moulding was recorded. Formal teaching was then given to the next group of medical staff rotating through the unit, and the same data was collected prospectively for that six-month period. Exclusion criteria included bilateral injuries, and polytrauma patients. A total of 1623 distal radial fractures were treated in our unit over the 12-month period, with 71 undergoing ORIF in the first 6 months and 39 in the second 6 months, this was statistically significant (p = 0.0009). Our study found that formal teaching and education significantly reduced the operation rate for distal radial fractures. This effect was most significant for extra-articular, dorsally angulated fractures of the distal radius. Our study proves that just 1 h of basic training at the beginning of an attachment can have significant benefits to both the unit and, more importantly, the patients. Copyright © 2013 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

Scaphoid Fracture

Directory of Open Access Journals (Sweden)

Esther Kim, BS

2018-04-01

Full Text Available History of present illness: A 25-year-old, right-handed male presented to the emergency department with left wrist pain after falling from a skateboard onto an outstretched hand two-weeks prior. He otherwise had no additional concerns, including no complaints of weakness or loss of sensation. On physical exam, there was tenderness to palpation within the anatomical snuff box. The neurovascular exam was intact. Plain films of the left wrist and hand were obtained. Significant findings: The anteroposterior (AP plain film of this patient demonstrates a full thickness fracture through the middle third of the scaphoid (red arrow, with some apparent displacement (yellow lines and subtle angulation of the fracture fragments (blue line. Discussion: The scaphoid bone is the most commonly fractured carpal bone accounting for 70%-80% of carpal fractures.1 Classically, it is sustained following a fall onto an outstretched hand (FOOSH. Patients should be evaluated for tenderness with palpation over the anatomical snuffbox, which has a sensitivity of 100% and specificity of 40%.2 Plain films are the initial diagnostic modality of choice and have a sensitivity of 70%, but are commonly falsely negative in the first two to six weeks of injury (false negative of 20%.3 The Mayo classification organizes scaphoid fractures as involving the proximal, mid, and distal portions of the scaphoid bone with mid-fractures being the most common.3 The proximal scaphoid is highly susceptible to vascular compromise because it depends on retrograde blood flow from the radial artery. Therefore, disruption can lead to serious sequelae including osteonecrosis, arthrosis, and functional impairment. Thus, a low threshold should be maintained for neurovascular evaluation and surgical referral. Patients with non-displaced scaphoid fractures should be placed in a thumb spica splint.3 Patients with even suspected scaphoid fractures should be placed in a thumb spica splint and re

Surrogate-based optimization of hydraulic fracturing in pre-existing fracture networks

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Chen, Mingjie; Sun, Yunwei; Fu, Pengcheng; Carrigan, Charles R.; Lu, Zhiming; Tong, Charles H.; Buscheck, Thomas A.

2013-08-01

Hydraulic fracturing has been used widely to stimulate production of oil, natural gas, and geothermal energy in formations with low natural permeability. Numerical optimization of fracture stimulation often requires a large number of evaluations of objective functions and constraints from forward hydraulic fracturing models, which are computationally expensive and even prohibitive in some situations. Moreover, there are a variety of uncertainties associated with the pre-existing fracture distributions and rock mechanical properties, which affect the optimized decisions for hydraulic fracturing. In this study, a surrogate-based approach is developed for efficient optimization of hydraulic fracturing well design in the presence of natural-system uncertainties. The fractal dimension is derived from the simulated fracturing network as the objective for maximizing energy recovery sweep efficiency. The surrogate model, which is constructed using training data from high-fidelity fracturing models for mapping the relationship between uncertain input parameters and the fractal dimension, provides fast approximation of the objective functions and constraints. A suite of surrogate models constructed using different fitting methods is evaluated and validated for fast predictions. Global sensitivity analysis is conducted to gain insights into the impact of the input variables on the output of interest, and further used for parameter screening. The high efficiency of the surrogate-based approach is demonstrated for three optimization scenarios with different and uncertain ambient conditions. Our results suggest the critical importance of considering uncertain pre-existing fracture networks in optimization studies of hydraulic fracturing.

XFEM modeling of hydraulic fracture in porous rocks with natural fractures

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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.

Failure and fracture of thin film materials for MEMS

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Jonnalagadda, Krishna Nagasai

Design and reliable operation of Microelectromechanical systems (MEMS) depend on the material parameters that influence the failure and fracture properties of brittle and metallic thin films. Failure in brittle materials is quantified by the onset of catastrophic fracture, while in metals, the onset of inelastic deformation is considered as failure as it increases the material compliance. This dissertation research developed new experimental methods to address three aspects on the failure response of these two categories of materials: (a) the role of microstructure and intrinsic stress gradients in the opening mode fracture of mathematically sharp pre-cracks in amorphous and polycrystalline brittle thin films, (b) the critical conditions for mixed mode I/II pre-cracks and their comparison with linear elastic fracture mechanics (LEFM) criteria for crack initiation in homogeneous materials, and (c) the strain rate sensitivity of textured nanocrystalline Au and Pt films with grain sizes of 38 nm and 25 nm respectively. One of the technical objectives of this research was to develop experimental methods and tools that could become standards in MEMS and thin film experimental mechanics. In this regard, a new method was introduced to conduct mode I and mixed mode I/II fracture studies with microscale thin film specimens containing sharp edge pre-cracks. The mode I experiments permitted the direct application of LEFM handbook solutions. On the other hand, the newly introduced mixed mode I/II experiments in thin films were conducted by establishing a new protocol that employs non-standard oblique edge pre-cracks and a numerical analysis based on the J-integral to calculate the stress intensity factors. Similarly, a new experimental protocol has been implemented to carry out experiments with metallic thin films at strain rates that vary by more than six orders of magnitude. The results of mode I fracture experiments concluded that grain inhomogeneity in polycrystalline

Defect vectors and path integrals in fracture mechanics

International Nuclear Information System (INIS)

Roche, R.L.

1979-01-01

Several criteria have been proposed in Elastic Plastic Fracture Mechanics. One of the most interesting ones is the J 1 criterion where J 1 is a path integral surrounding the crack tip. Other path integrals (or surface integrals in 3D problems) can be used. But all these integrals are introduced on an elastic basis, though they are applied in plasticity. This paper shows that it is possible to introduce these integrals without any reference to the elastic behavior of the material. The method is based on the 'defect vector theory' which is an extension of the energy-momentum tensor theory. (orig.)

Mortality Following Periprosthetic Proximal Femoral Fractures Versus Native Hip Fractures.

Science.gov (United States)

Boylan, Matthew R; Riesgo, Aldo M; Paulino, Carl B; Slover, James D; Zuckerman, Joseph D; Egol, Kenneth A

2018-04-04

The number of periprosthetic proximal femoral fractures is expected to increase with the increasing prevalence of hip arthroplasties. While native hip fractures have a well-known association with mortality, there are currently limited data on this outcome among the subset of patients with periprosthetic proximal femoral fractures. Using the New York Statewide Planning and Research Cooperative System, we identified patients from 60 to 99 years old who were admitted to a hospital in the state with a periprosthetic proximal femoral fracture (n = 1,655) or a native hip (femoral neck or intertrochanteric) fracture (n = 97,231) between 2006 and 2014. Within the periprosthetic fracture cohort, the indication for the existing implant was not available in the data set. We used mixed-effects regression models to compare mortality at 1 and 6 months and 1 year for periprosthetic compared with native hip fractures. The risk of mortality for patients who sustained a periprosthetic proximal femoral fracture was no different from that for patients who sustained a native hip fracture at 1 month after injury (3.2% versus 4.6%; odds ratio [OR], 0.90; 95% confidence interval [CI], 0.68 to 1.19; p = 0.446), but was lower at 6 months (3.8% versus 6.5%; OR, 0.74; 95% CI, 0.57 to 0.95; p = 0.020) and 1 year (9.7% versus 15.9%; OR, 0.71; 95% CI, 0.60 to 0.85; p accounting for age and comorbidities. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Length-scales of Slab-induced Asthenospheric Deformation from Geodynamic Modeling, Mantle Deformation Fabric, and Synthetic Shear Wave Splitting

Science.gov (United States)

Jadamec, M. A.; MacDougall, J.; Fischer, K. M.

2017-12-01

The viscosity structure of the Earth's interior is critically important, because it places a first order constraint on plate motion and mantle flow rates. Geodynamic models using a composite viscosity based on experimentally derived flow laws for olivine aggregates show that lateral viscosity variations emerge in the upper mantle due to the subduction dynamics. However, the length-scale of this transition is still not well understood. Two-dimensional numerical models of subduction are presented that investigate the effect of initial slab dip, maximum yield stress (slab strength), and viscosity formulation (Newtonian versus composite) on the emergent lateral viscosity variations in the upper-mantle and magnitude of slab-driven mantle flow velocity. Significant viscosity reductions occur in regions of large flow velocity gradients due to the weakening effect of the dislocation creep deformation mechanism. The dynamic reductions in asthenospheric viscosity (less than 1018 Pa s) occur within approximately 500 km from driving force of the slab, with peak flow velocities occurring in models with a lower yield stress (weaker slab) and higher stress exponent. This leads to a sharper definition of the rheological base of the lithosphere and implies lateral variability in tractions along the base of the lithosphere. As the dislocation creep mechanism also leads to mantle deformation fabric, we then examine the spatial variation in the LPO development in the asthenosphere and calculate synthetic shear wave splitting. The models show that olivine LPO fabric in the asthenosphere generally increases in alignment strength with increased proximity to the slab, but can be transient and spatially variable on small length scales. The vertical flow fields surrounding the slab tip can produce shear-wave splitting variations with back-azimuth that deviate from the predictions of uniform trench-normal anisotropy, a result that bears on the interpretation of complexity in shear

Assessment of fracture risk

International Nuclear Information System (INIS)

Kanis, John A.; Johansson, Helena; Oden, Anders; McCloskey, Eugene V.

2009-01-01

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.

Surfing Behind a Boat: Quality and Reliability of Online Resources on Scaphoid Fractures.

Science.gov (United States)

Nassiri, Mujtaba; Mohamed, Osama; Berzins, Arvids; Aljabi, Yasser; Mahmood, Talat; Chenouri, Shojaeddin; O'Grady, Paul

2016-10-01

Patients seeking information and advice on treatment of scaphoid fractures unknowingly confront longstanding medical controversies surrounding the management of this condition. However, there are no studies specifically looking into the quality and reliability of online information on scaphoid fractures. We identified 44 unique websites for evaluation using the term "scaphoid fractures". The websites were categorized by type and assessed using the DISCERN score, the Journal of the American Medical Association (JAMA) benchmark criteria and the Health on the net (HON) code. The majority of websites were commercial (n = 13) followed by academic (n = 12). Only seven of the websites were HON certified. The mean DISCERN score was 43.8. Only 4 websites scored 63 or above representing excellent quality with minimal shortcomings but 13 websites scored 38 or below representing poor or very poor quality. The mean JAMA benchmark criteria score was 2.2. The Governmental and Non-Profit Organizations category websites had the highest mean JAMA benchmark score. The websites that displayed the HON-code seal had higher mean DISCERN scores and higher mean JAMA benchmark scores compared to websites that did not display the seal. Good quality health information is certainly available on the Internet. However, it is not possible to predict with certainty which sites are of higher quality. We suggest clinicians should have a responsibility to educate their patients regarding the unregulated nature of medical information on the internet and proactively provide patients with educational resources and thus help them make smart and informed decisions.

The radiation swelling effect on fracture properties and fracture mechanisms of irradiated austenitic steels. Part I. Ductility and fracture toughness

Energy Technology Data Exchange (ETDEWEB)

Margolin, B., E-mail: mail@crism.ru; Sorokin, A.; Shvetsova, V.; Minkin, A.; Potapova, V.; Smirnov, V.

2016-11-15

The radiation swelling effect on the fracture properties of irradiated austenitic steels under static loading has been studied and analyzed from the mechanical and physical viewpoints. Experimental data on the stress-strain curves, fracture strain, fracture toughness and fracture mechanisms have been represented for austenitic steel of 18Cr-10Ni-Ti grade (Russian analog of AISI 321 steel) irradiated up to neutron dose of 150 dpa with various swelling. Some phenomena in mechanical behaviour of irradiated austenitic steels have been revealed and explained as follows: a sharp decrease of fracture toughness with swelling growth; untypical large increase of fracture toughness with decrease of the test temperature; some increase of fracture toughness after preliminary cyclic loading. Role of channel deformation and channel fracture has been clarified in the properties of irradiated austenitic steel and different tendencies to channel deformation have been shown and explained for the same austenitic steel irradiated at different temperatures and neutron doses.

Treatment of pediatric femoral shaft fractures by stainless steel and titanium elastic nail system: A randomized comparative trial.

Science.gov (United States)

Gyaneshwar, Tank; Nitesh, Rustagi; Sagar, Tomar; Pranav, Kothiyal; Rustagi, Nitesh

2016-08-01

Literature suggests that the lower modulus of elasticity of titanium makes it ideal for use in children compared with stainless steel. Better fracture stability was observed in association with titanium nails on torsional and axial compression testing. However, stainless steel nails are stiffer than titanium counterparts, which may provide a rigid construct when fixing paediatric femoral shaft fractures. Complications have been observed more frequently by various researchers when titanium nails are used for fracture fixation in patients with increasing age or weight. The concept of this study was to compare the functional outcome after internal fixation with titanium elastic nail system and stainless steel elastic nail system in paediatric femoral shaft fractures. The study was conducted on 34 patients admitted in the department of orthopaedics, LLRM Medical College & SVBP Hospital, Meerut, India from January 2013 to August 2014. We included patients aged 5-12 years with fracture of the femoral shaft, excluding compound fractures, pathological fractures and other lower limb fractures. Patients were treated by titanium (n=17) or stainless steel (n=17) elastic nail system and followed up for one year. The clinical parameters like range of motion at hip and knee joints, time to full weight bearing on the operated limb and radiological parameters like time to union were compared between two groups. A special note was made of intra- and post-operative complications. Functional outcomes were analysed according to Flynn criteria. Based on the Flynn criteria, 59% of patients had excellent results, 41% had satisfactory results, and no one showed poor results. There was no clinically significant difference between the two groups with respect to time to union and full weight bearing. But the incidence of puncture of the opposite cortex while inserting the nail and trying to advance it through the diaphysis during operation is greatly different. Only one such case was observed

Simulation of counter-current imbibition in water-wet fractured reservoirs based on discrete-fracture model

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Wang Yueying

2017-08-01

Full Text Available Isolated fractures usually exist in fractured media systems, where the capillary pressure in the fracture is lower than that of the matrix, causing the discrepancy in oil recoveries between fractured and non-fractured porous media. Experiments, analytical solutions and conventional simulation methods based on the continuum model approach are incompetent or insufficient in describing media containing isolated fractures. In this paper, the simulation of the counter-current imbibition in fractured media is based on the discrete-fracture model (DFM. The interlocking or arrangement of matrix and fracture system within the model resembles the traditional discrete fracture network model and the hybrid-mixed-finite-element method is employed to solve the associated equations. The Behbahani experimental data validates our simulation solution for consistency. The simulation results of the fractured media show that the isolated-fractures affect the imbibition in the matrix block. Moreover, the isolated fracture parameters such as fracture length and fracture location influence the trend of the recovery curves. Thus, the counter-current imbibition behavior of media with isolated fractures can be predicted using this method based on the discrete-fracture model.

Criteria for fracture initiation at hydrides in zirconium alloys. Pt. 1

International Nuclear Information System (INIS)

Shi, S.Q.; Puls, M.P.

1994-01-01

A theoretical framework for the initiation of delayed hydride cracking (DHC) in zirconium is proposed for two different types of initiating sites, i.e., a sharp crack tip (considered in this part) and a shallow notch (considered in part II). In the present part I, an expression for K IH is derived which shows that K IH depends on the size and shape of the hydride precipitated at the crack tip, the yield stress and elastic moduli of the material and the fracture stress of the hydride. If the hydride at the crack tip extends in length at constant thickness, then K IH increases as the square root of the hydride thickness. Thus a microstructure favouring the formation of thicker hydrides at the crack tip would result in an increased K IH . K IH increases slightly with temperature up to a temperature at which there is a more rapid increase. The temperature at which there is a more rapid increase in K IH will increase as the yield stress increases. The model also predicts that an increase in yield stress due to irradiation will cause an overall slight decrease in K IH compared to unirradiated material. There is good agreement between the overall predictions of the theory and experimental results. It is suggested that more careful evaluations of some key parameters are required to improve on the theoretical estimates. (orig.)

Fracture characteristics in Japanese rock

International Nuclear Information System (INIS)

Ijiri, Yuji; Sawada, Atsushi; Akahori, Kuniaki

1999-11-01

It is crucial for the performance assessment of geosphere to evaluate the characteristics of fractures that can be dominant radionuclide migration pathways from a repository to biosphere. This report summarizes the characteristics of fractures obtained from broad literature surveys and the fields surveys at the Kamaishi mine in northern Japan and at outcrops and galleries throughout the country. The characteristics of fractures described in this report are fracture orientation, fracture shape, fracture frequency, fracture distribution in space, transmissivity of fracture, fracture aperture, fracture fillings, alteration halo along fracture, flow-wetted surface area in fracture, and the correlation among these characteristics. Since granitic rock is considered the archetype fractured media, a large amount of fracture data is available in literature. In addition, granitic rock has been treated as a potential host rock in many overseas programs, and has JNC performed a number of field observations and experiments in granodiorite at the Kamaishi mine. Therefore, the characteristics of fractures in granitic rock are qualitatively and quantitatively clarified to some extent in this report, while the characteristics of fractures in another rock types are not clarified. (author)

Cough-induced rib fractures.

Science.gov (United States)

Hanak, Viktor; Hartman, Thomas E; Ryu, Jay H

2005-07-01

To define the demographic, clinical, and radiological features of patients with cough-induced rib fractures and to assess potential risk factors. For this retrospective, single-center study, we identified all cases of cough-induced rib fractures diagnosed at the Mayo Clinic in Rochester, Minn, over a 9-year period between January 1, 1996, and January 31, 2005. Bone densitometry data from patients' medical records were analyzed, and T scores were used to classify patients into bone density categories. The mean +/- SD age of the 54 study patients at presentation was 55+/-17 years, and 42 patients (78%) were female. Patients presented with chest wall pain after onset of cough. Rib fracture was associated with chronic cough (> or =3 weeks' duration) in 85% of patients. Rib fractures were documented by chest radiography, rib radiography, computed tomography, or bone scan. Chest radiography had been performed in 52 patients and revealed rib fracture in 30 (58%). There were 112 fractured ribs in 54 patients. One half of patients had more than one fractured rib. Right-sided rib fractures alone were present in 17 patients (26 fractured ribs), left-sided in 23 patients (35 fractured ribs), and bilateral in 14 patients (51 fractured ribs). The most commonly fractured rib on both sides was rib 6. The fractures were most common at the lateral aspect of the rib cage. Bone densitometry was done in 26 patients and revealed osteopenia or osteoporosis in 17 (65%). Cough-induced rib fractures occur primarily in women with chronic cough. Middle ribs along the lateral aspect of the rib cage are affected most commonly. Although reduced bone density is likely a risk factor, cough-induced rib fractures can occur in the presence of normal bone density.

Influence of perforation erosion on multiple growing hydraulic fractures in multi-stage fracturing

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Yongming Li

2018-02-01

Full Text Available In multi-stage hydraulic fracturing, the limited-entry method is widely used to promote uniform growth of multiple fractures. However, this method's effectiveness may be lost because the perforations will be eroded gradually during the fracturing period. In order to study the influence of perforation erosion on multiple growing hydraulic fractures, we combined the solid–fluid coupled model of hydraulic fracture growth with an empirical model of perforation erosion to implement numerical simulation. The simulations show clearly that the erosion of perforation will significantly deteriorate the non-uniform growth of multiple fractures. Based on the numerical model, we also studied the influences of proppant concentration and injection rates on perforation erosion in multi-stage hydraulic fracturing. The results indicate that the initial erosion rates become higher with the rising proppant concentration, but the growth of multiple hydraulic fractures is not sensitive to the varied proppant concentration. In addition, higher injection rates are beneficial significantly to the limited-entry design, leading to more uniform growth of fractures. Thus, in multi-stage hydraulic fracturing enough high injection rates are proposed to keep uniform growths. Keywords: Unconventional oil and gas reservoir, Horizontal well, Perforation friction, Perforation erosion, Multi-stage hydraulic fracturing, Numerical simulation, Mathematic model, Uniform growth of fractures

Assessing the Accuracy and Reliability of Root Crack and Fracture Detection in Teeth Using Sweep Imaging with Fourier Transform (SWIFT) Magnetic Resonance Imaging (MRI)

Science.gov (United States)

Schuurmans, Tyler J.

Introduction: Magnetic Resonance Imaging (MRI) has the potential to aid in determining the presence and extent of cracks/fractures in teeth due to more advantageous contrast, without ionizing radiation. An MRI technique called Sweep Imaging with Fourier Transform (SWIFT) has overcome many of the inherent difficulties of conventional MRI with detecting fast-relaxing signals from densely mineralized dental tissues. The objectives of this in vitro investigation were to develop MRI criteria for root crack/fracture identification in teeth and to establish intra- and inter-rater reliabilities and corresponding sensitivity and specificity values for the detection of tooth-root cracks/fractures in SWIFT MRI and limited field of view (FOV) CBCT. Materials and Methods: MRI-based criteria for crack/fracture appearance was developed by an MRI physicist and 6 dentists, including 3 endodontists and 1 Oral and Maxillofacial (OMF) radiologist. Twenty-nine human adult teeth previously extracted following clinical diagnosis by a board-certified endodontist of a root crack/fracture were frequency-matched to 29 non-cracked controls. Crack/fracture status confirmation was performed with magnified visual inspection, transillumination and vital staining. Samples were scanned with two 3D imaging modalities: 1) SWIFT MRI (10 teeth/scan) via a custom oral radiofrequency (RF) coil and a 90cm, 4-T magnet; 2) Limited FOV CBCT (1 tooth/scan) via a Carestream (CS) 9000 (Rochester, NY). Following a training period, a blinded 4-member panel (3 endodontists, 1 OMF radiologist) evaluated the images with a proportion randomly re-tested to establish intra-rater reliability. Overall observer agreement was measured using Cohen's kappa and levels of agreement judged using the criteria of Landis and Koch. Sensitivity and specificity were computed with 95% confidence interval (CI); statistical significance was set at alpha ≤ 0.05. Results: MRI-based crack/fracture criteria were defined as 1-2 sharply

Probabilistic fracture mechanics analysis for leak-before-break evaluation of light water reactor's piping

International Nuclear Information System (INIS)

Yoshimura, Shinobu; Yagawa, Genki; Akiba, Hiroshi; Fujioka, Terutaka.

1997-01-01

This paper describes Probabilistic Fracture Mechanics (PFM) analyses for quantitative evaluation of the likelihood of Leak-Before-Break (LBB) of Light Water Reactor's (LWR's) piping. The PFM analyses in general assume probabilistic distributions of initial crack size, applied stress cycles, crack growth laws, fracture criteria, leakage detection capability, defect inspection capability and so on. Referring to the deterministic procedure for LBB evaluation, most appropriate PFM models and data for LBB evaluation are discussed. Here the LBB index is newly proposed in order to quantitatively evaluate the likelihood of LBB. Through intensive sensitivity analyses, it is clarified that the LBB is more likely to occur for larger diameter pipe; the performance of leakage detection significantly affects the LBB likelihood; the LBB likelihood increases with plant's aging even conservatively assuming leak detection capability; the R6 method (Category 1, Option 1) for fracture criterion gives very conservative results; and In-Service Inspection (ISI) reduces the increase rate of failure probability than the failure probability itself. (author)

Characteristic fracture spacing in primary and secondary recovery for naturally fractured reservoirs

NARCIS (Netherlands)

Gong, J.; Rossen, W.R.

2018-01-01

If the aperture distribution is broad enough in a naturally fractured reservoir, even one where the fracture network is highly inter-connected, most fractures can be eliminated without significantly affecting the flow through the fracture network. During a waterflood or enhanced-oil-recovery

A STUDY OF UNSTABLE INTERTROCHANTERIC FEMORAL FRACTURES TREATED BY TROCHANTERIC FEMORAL NAIL

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Sreenivasa Neikar

2017-11-01

Full Text Available BACKGROUND Intertrochanteric fracture is one of the most common fracture of the hip especially in the elderly. The incidence of intertrochanteric fracture is rising because of the increase in number of elderly population along with superadded osteoporosis. MATERIALS AND METHODS Study included cases of unstable intertrochanteric fractures (AO and OTA Classification 31-A2 and 31-A3 fracture patterns that were operated with the short trochanteric femoral nail, which fitted into the inclusion criteria done in medical college hospital, Vijayanagara Institute of Medical Sciences, Bellary, from February 2015 to September 2016. RESULTS The age distribution was from 40 to 80 years. The largest group of patients were from 61 to 70 years. The average age was 60.5 years. The number of male patients in our series was 20 (66.7% and female was 10 (33.3%. Right side was affected in 11 cases (36.7% and left side in 19 cases (63.3%. Good reduction was achieved in 23 patients (76.7%. Acceptable reduction was achieved in 7 (23.3% patients due to severe comminution. In our study, 25 patients (83.33% had no complications. We encountered one intraoperative complication in the form of greater trochanter splintering, while inserting the nail. In our study, we encountered following postoperative complications. We noticed one case of delayed union, one case of Z effect and 2 cases of varus malunion. CONCLUSION We conclude that short trochanteric femoral nail provides good fixation for unstable intertrochanteric fractures if proper preoperative planning, good reduction and surgical technique are followed leading to high rate of bone union and minimal soft tissue damage especially for Asian patients with relatively small femora.

Fracture mechanical materials characterisation

International Nuclear Information System (INIS)

Wallin, K.; Planman, T.; Nevalainen, M.

1998-01-01

The experimental fracture mechanics development has been focused on the determination of reliable lower-bound fracture toughness estimates from small and miniature specimens, in particular considering the statistical aspects and loading rate effects of fracture mechanical material properties. Additionally, materials aspects in fracture assessment of surface cracks, with emphasis on the transferability of fracture toughness data to structures with surface flaws have been investigated. Further a modified crack-arrest fracture toughness test method, to increase the effectiveness of testing, has been developed. (orig.)

Depression and risk of fracture and bone loss: an updated meta-analysis of prospective studies.

Science.gov (United States)

Wu, Q; Liu, B; Tonmoy, S

2018-03-12

This meta-analysis pooled results from 23 qualifying individual cohort studies and found that depression was significantly associated with an increased risk of fractures and bone loss. The association between depression and risk of fracture remains controversial. We conducted a comprehensive meta-analysis to examine the effect of depression on the risk of osteoporotic fractures and bone loss. We searched databases and reviewed citations in relevant articles for eligible cohort studies. Two investigators independently conducted study selection, appraisal, and data abstraction through the use of a standardized protocol. Random effect models were used for meta-analysis. Cochrane Q and I 2 statistics were used to assess heterogeneity. Funnel plots and rank correlation tests were used to evaluate publication bias. Twenty-three studies were included for meta-analysis. In studies that reported hazard ratio (HR) as the outcome (nine studies [n = 309,862]), depression was associated with 26% increase in fracture risk (HR = 1.26, 95% CI, 1.10-1.43, p meta-analysis having modified inclusion criteria and in different subgroup analyses as well. Significant heterogeneity was observed in the meta-analysis; however, no significant publication bias was detected. Depression is associated with a significant increased risk in fracture and bone loss. Effective prevention may decrease such risk.

Fractures and fracture infillings of the Eye-Dashwa Lakes pluton, Atikokan, Ontario

International Nuclear Information System (INIS)

Stone, Denver; Kamineni, D.C.

1982-01-01

Fractures in the Eye-Dashwa pluton near Atikokan, Ontario can be subdivided on the basis of their filling materials. These materials include aplite, epidote, chlorite, and gypsum-carbonate-clay, listed in order of decreasing age established from crosscutting relations. Textues indicate that infilling occurred during fracture growth. Continuous cooling of the pluton during fracturing is inferred from the expected crystallization temperatures of fillings. Fracturing began before the pluton was completely solidified (650-600 0 C) and continued to temperatures below 100 0 C. Many fractures appear to have been sealed by the filling materials after initiation but were subsequently sheared and filled by lower temperatue materials. Apparently the majority of fractures formed during or immediately after pluton solidification and new fractures became smaller and more restricted in location as cooling progressed. Fractures and filling materials are seen as important features in assessing the possibility of movement of radionuclides in aqueous solutions away from a nuclear fuel waste repository

Validation of three tools for identifying painful new osteoporotic vertebral fractures in older Chinese men: bone mineral density, Osteoporosis Self-Assessment Tool for Asians, and fracture risk assessment tool.

Science.gov (United States)

Lin, JiSheng; Yang, Yong; Fei, Qi; Zhang, XiaoDong; Ma, Zhao; Wang, Qi; Li, JinJun; Li, Dong; Meng, Qian; Wang, BingQiang

2016-01-01

This cross-sectional study compared three tools for predicting painful new osteoporotic vertebral fractures (PNOVFs) in older Chinese men: bone mineral density (BMD), the Osteoporosis Self-Assessment Tool for Asians (OSTA), and the World Health Organization fracture risk assessment tool (FRAX) (without BMD). Men aged ≥50 years were apportioned to a group for men with fractures who had undergone percutaneous vertebroplasty (n=111), or a control group of healthy men (n=385). Fractures were verified on X-ray and magnetic resonance imaging. BMD T-scores were determined by dual energy X-ray absorptiometry. Diagnosis of osteoporosis was determined by a BMD T-score of ≤2.5 standard deviations below the average for a young adult at peak bone density at the femoral neck, total hip, or L1-L4. Demographic and clinical risk factor data were self-reported through a questionnaire. BMD, OSTA, and FRAX scores were assessed for identifying PNOVFs via receiver-operating characteristic (ROC) curves. Optimal cutoff points, sensitivity, specificity, and areas under the ROC curves (AUCs) were determined. Between the men with fractures and the control group, there were significant differences in BMD T-scores (at femoral neck, total hip, and L1-L4), and OSTA and FRAX scores. In those with fractures, only 53.15% satisfied the criteria for osteoporosis. Compared to BMD or OSTA, the FRAX score had the best predictive value for PNOVFs: the AUC of the FRAX score (cutoff =2.9%) was 0.738, and the sensitivity and specificity were 82% and 62%, respectively. FRAX may be a valuable tool for identifying PNOVFs in older Chinese men.

Computed tomograms of blowout fracture

International Nuclear Information System (INIS)

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

1985-01-01

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)

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).

Facial Fractures.

Science.gov (United States)

Ricketts, Sophie; Gill, Hameet S; Fialkov, Jeffery A; Matic, Damir B; Antonyshyn, Oleh M

2016-02-01

After reading this article, the participant should be able to: 1. Demonstrate an understanding of some of the changes in aspects of facial fracture management. 2. Assess a patient presenting with facial fractures. 3. Understand indications and timing of surgery. 4. Recognize exposures of the craniomaxillofacial skeleton. 5. Identify methods for repair of typical facial fracture patterns. 6. Discuss the common complications seen with facial fractures. Restoration of the facial skeleton and associated soft tissues after trauma involves accurate clinical and radiologic assessment to effectively plan a management approach for these injuries. When surgical intervention is necessary, timing, exposure, sequencing, and execution of repair are all integral to achieving the best long-term outcomes for these patients.

Outcomes of Surgical Treatment for Anterior Tibial Stress Fractures in Athletes: A Systematic Review.

Science.gov (United States)

Chaudhry, Zaira S; Raikin, Steven M; Harwood, Marc I; Bishop, Meghan E; Ciccotti, Michael G; Hammoud, Sommer

2017-12-01

Although most anterior tibial stress fractures heal with nonoperative treatment, some may require surgical management. To our knowledge, no systematic review has been conducted regarding surgical treatment strategies for the management of chronic anterior tibial stress fractures from which general conclusions can be drawn regarding optimal treatment in high-performance athletes. This systematic review was conducted to evaluate the surgical outcomes of anterior tibial stress fractures in high-performance athletes. Systematic review; Level of evidence, 4. In February 2017, a systematic review of the PubMed, MEDLINE, Cochrane, SPORTDiscus, and CINAHL databases was performed to identify studies that reported surgical outcomes for anterior tibial stress fractures. Articles meeting the inclusion criteria were screened, and reported outcome measures were documented. A total of 12 studies, published between 1984 and 2015, reporting outcomes for the surgical treatment of anterior tibial stress fractures were included in this review. All studies were retrospective case series. Collectively, surgical outcomes for 115 patients (74 males; 41 females) with 123 fractures were evaluated in this review. The overall mean follow-up was 23.3 months. The most common surgical treatment method reported in the literature was compression plating (n = 52) followed by drilling (n = 33). Symptom resolution was achieved in 108 of 123 surgically treated fractures (87.8%). There were 32 reports of complications, resulting in an overall complication rate of 27.8%. Subsequent tibial fractures were reported in 8 patients (7.0%). Moreover, a total of 17 patients (14.8%) underwent a subsequent procedure after their initial surgery. Following surgical treatment for anterior tibial stress fracture, 94.7% of patients were able to return to sports. The available literature indicates that surgical treatment of anterior tibial stress fractures is associated with a high rate of symptom resolution and return

COHORT STUDY OF DISPLACED SUPRACONDYLAR FRACTURE TREATED IN TERTIARY CARE INSTITUTE IN PONDICHERY WITH RADIOLOGICAL ASSISTANCE WITH MEDIAL ‘K’ WIRE FIRST FROM 2008-2016

Directory of Open Access Journals (Sweden)

Aravindan Kalamegam

2017-10-01

Full Text Available BACKGROUND Supracondylar fracture in children when it is displaced, it is very difficult to reduce the fracture. That too after reduction, maintaining the reduction is very difficult. While reducing the fracture in closed reduction with lateral pinning first the result is not predictably good. Cross pinning will be giving mechanically stable fixation than lateral pinning alone. Lateral pinning alone imparts less rotational stability of fracture. Our aim of study is to prevent rotational instability by putting medial pinning first by avoiding the ulnar nerve injury using radiological assistance followed by lateral pinning. MATERIALS AND METHODS One hundred and six cases of displaced supracondylar fracture were included in study. The mean age of the patient was 7 yrs. (3-12 yrs., the male and female patient ratio was 72:34 and left side was involved in 63 patients whereas right side in 43 patients. The most common mode of trauma was fall from height on outstretched hand with elbow in extension. All the 106 patients were consecutively admitted. Patient had extension type of injury with 63 patients had Gartland type III fracture and 43 had Gartland type II fracture. Posteromedial displacement was noted in 63 patients whereas posterolateral displacement noted in 43 patients. In all cases, medial K wire was first inserted after closed reduction, then after stabilising the fractured rotation using image guidance. Lateral K-wire was removed on 3 weeks (21 days and follow up was done at 6 weeks and 12 weeks when they were evaluated according to Flynn’s criteria. RESULTS Results were graded according to Flynn’s criteria. CONCLUSION Medial K wire technique provides stable fixation and rotational stability has been correlated according to this technique.

Opportunity for Stakeholder Input on EPA's Hydraulic Fracturing Research Study: Criteria for Selecting Case Studies

Science.gov (United States)

EPA sought advice from stakeholders regarding potential case studies, stakeholder were invited to provide suggestions and refinements to the prioritization of criteria and information listed in Table 1 of the document.

Intra-articular Physeal Fractures of the Distal Femur: A Frequently Missed Diagnosis in Adolescent Athletes.

Science.gov (United States)

Pennock, Andrew T; Ellis, Henry B; Willimon, Samuel C; Wyatt, Charles; Broida, Samuel E; Dennis, M Morgan; Bastrom, Tracey

2017-10-01

Intra-articular physeal fractures of the distal femur are an uncommon injury pattern, with only a few small case series reported in the literature. To pool patients from 3 high-volume pediatric centers to better understand this injury pattern, to determine outcomes of surgical treatment, and to assess risk factors for complications. Case series; Level of evidence, 4. A multicenter retrospective review of all patients presenting with an intra-articular physeal fracture between 2006 and 2016 was performed. Patient demographic and injury data, surgical data, and postoperative outcomes were documented. Radiographs were evaluated for fracture classification (Salter-Harris), location, and displacement. Differences between patients with and without complications were compared by use of analysis of variance or chi-square tests. A total of 49 patients, with a mean age of 13.5 years (range, 7-17 years), met the inclusion criteria. The majority of fractures were Salter-Harris type III fractures (84%) involving the medial femoral condyle (88%). Football was responsible for 50% of the injuries. The initial diagnosis was missed in 39% of cases, and advanced imaging showed greater mean displacement (6 mm) compared with radiographs (3 mm). All patients underwent surgery and returned to sport with "good to excellent" results after 2 years. Complications were more common in patients with wide-open growth plates, patients with fractures involving the lateral femoral condyle, and patients who were casted ( P < .05). Clinicians evaluating skeletally immature athletes (particularly football players) with acute knee injuries should maintain a high index of suspicion for an intra-articular physeal fracture. These fractures are frequently missed, and advanced imaging may be required to establish the diagnosis. Leg-length discrepancies and angular deformities are not uncommon, and patients should be monitored closely. Surgical outcomes are good when fractures are identified, with high rates

Mechanics of Hydraulic Fractures

Science.gov (United States)

Detournay, Emmanuel

2016-01-01

Hydraulic fractures represent a particular class of tensile fractures that propagate in solid media under pre-existing compressive stresses as a result of internal pressurization by an injected viscous fluid. The main application of engineered hydraulic fractures is the stimulation of oil and gas wells to increase production. Several physical processes affect the propagation of these fractures, including the flow of viscous fluid, creation of solid surfaces, and leak-off of fracturing fluid. The interplay and the competition between these processes lead to multiple length scales and timescales in the system, which reveal the shifting influence of the far-field stress, viscous dissipation, fracture energy, and leak-off as the fracture propagates.

Fracture in Soft Materials

DEFF Research Database (Denmark)

Hassager, Ole

Fracture is a phenomenon that is generally associated with solids. A key element in fracture theory is the so-called weakest link idea that fracture initiates from the largest pre-existing material imperfection. However, recent work has demonstrated that fracture can also happen in liquids, where...... surface tension will act to suppress such imperfections. Therefore, the weakest link idea does not seem immediately applicable to fracture in liquids. This presentation will review fracture in liquids and argue that fracture in soft liquids is a material property independent of pre-existing imperfections....... The following questions then emerge: What is the material description needed to predict crack initiation, crack speed and crack shape in soft materials and liquids....

Seismic characteristics of tensile fracture growth induced by hydraulic fracturing

Science.gov (United States)

Eaton, D. W. S.; Van der Baan, M.; Boroumand, N.

2014-12-01

Hydraulic fracturing is a process of injecting high-pressure slurry into a rockmass to enhance its permeability. Variants of this process are used for unconventional oil and gas development, engineered geothermal systems and block-cave mining; similar processes occur within volcanic systems. Opening of hydraulic fractures is well documented by mineback trials and tiltmeter monitoring and is a physical requirement to accommodate the volume of injected fluid. Numerous microseismic monitoring investigations acquired in the audio-frequency band are interpreted to show a prevalence of shear-dominated failure mechanisms surrounding the tensile fracture. Moreover, the radiated seismic energy in the audio-frequency band appears to be a miniscule fraction (<< 1%) of the net injected energy, i.e., the integral of the product of fluid pressure and injection rate. We use a simple penny-shaped crack model as a predictive framework to describe seismic characteristics of tensile opening during hydraulic fracturing. This model provides a useful scaling relation that links seismic moment to effective fluid pressure within the crack. Based on downhole recordings corrected for attenuation, a significant fraction of observed microseismic events are characterized by S/P amplitude ratio < 5. Despite the relatively small aperture of the monitoring arrays, which precludes both full moment-tensor analysis and definitive identification of nodal planes or axes, this ratio provides a strong indication that observed microseismic source mechanisms have a component of tensile failure. In addition, we find some instances of periodic spectral notches that can be explained by an opening/closing failure mechanism, in which fracture propagation outpaces fluid velocity within the crack. Finally, aseismic growth of tensile fractures may be indicative of a scenario in which injected energy is consumed to create new fracture surfaces. Taken together, our observations and modeling provide evidence that

Malnutrition and chronic inflammation as risk factors for sarcopenia in elderly patients with hip fracture.

Science.gov (United States)

Yoo, Jun-Il; Ha, Yong-Chan; Choi, Hana; Kim, Kyu-Hwang; Lee, Young-Kyun; Koo, Kyung-Hoi; Park, Ki-Soo

2018-01-01

To evaluate malnutrition and chronic inflammation as risk factors for sarcopenia in elderly patients with hip fractures, as defined by the criteria of the Asian Working Group on Sarcopenia (AWGS). A total of 327 elderly patients with hip fractures were enrolled in this retrospective observational study. The main outcome measure was the nutritional status and nutritional risk factors for sarcopenia in elderly patients. Diagnosis of sarcopenia was made according to the guidelines of the AWGS. Whole body densitometry analysis was used to measure skeletal muscle mass, and muscle strength was evaluated by handgrip testing. Multivariable regression analysis was utilized to analyze the nutritional risk factors for sarcopenia in patients with hip fractures. Of 327 patients with hip fractures (78 men and 249 women), the prevalence of sarcopenia was 60.3% and 30.1% in men and women, respectively. The rates of three indicators of malnutrition in men and women (low BMI, hypoalbuminemia, and hypoproteinemia) in sarcopenia patients with hip fractures were 23.4%, 31.9%, and 53.2% and 21.3%, 21.3%, and 37.3%, respectively. The prevalence of markers of chronic inflammation (increased CRP and ESR) in men and women with sarcopenia and hip fractures were 74.9% and 52.2%, and 49.3% and 85.1%, respectively. After adjusting for covariates, low BMI and hypoproteinemia in women were associated with a 2.9- and 2.1-fold greater risk of sarcopenia than non-sarcopenia, respectively. The present study revealed a strong relationship between sarcopenia and malnutrition and chronic inflammatory factors in elderly patients with hip fractures.

Pathological fractures in children

Science.gov (United States)

De Mattos, C. B. R.; Binitie, O.; Dormans, J. P.

2012-01-01

Pathological fractures in children can occur as a result of a variety of conditions, ranging from metabolic diseases and infection to tumours. Fractures through benign and malignant bone tumours should be recognised and managed appropriately by the treating orthopaedic surgeon. The most common benign bone tumours that cause pathological fractures in children are unicameral bone cysts, aneurysmal bone cysts, non-ossifying fibromas and fibrous dysplasia. Although pathological fractures through a primary bone malignancy are rare, these should be recognised quickly in order to achieve better outcomes. A thorough history, physical examination and review of plain radiographs are crucial to determine the cause and guide treatment. In most benign cases the fracture will heal and the lesion can be addressed at the time of the fracture, or after the fracture is healed. A step-wise and multidisciplinary approach is necessary in caring for paediatric patients with malignancies. Pathological fractures do not have to be treated by amputation; these fractures can heal and limb salvage can be performed when indicated. PMID:23610658

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 (fashion as pressure increased. We also observed that permeability decreased with increasing fluid flow rate indicating that flow did not follow Darcy's Law, possibly due to non-laminar flow conditions, and 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.

Fluid-driven fracture propagation in heterogeneous media: Probability distributions of fracture trajectories.

Science.gov (United States)

Santillán, David; Mosquera, Juan-Carlos; Cueto-Felgueroso, Luis

2017-11-01

Hydraulic fracture trajectories in rocks and other materials are highly affected by spatial heterogeneity in their mechanical properties. Understanding the complexity and structure of fluid-driven fractures and their deviation from the predictions of homogenized theories is a practical problem in engineering and geoscience. We conduct a Monte Carlo simulation study to characterize the influence of heterogeneous mechanical properties on the trajectories of hydraulic fractures propagating in elastic media. We generate a large number of random fields of mechanical properties and simulate pressure-driven fracture propagation using a phase-field model. We model the mechanical response of the material as that of an elastic isotropic material with heterogeneous Young modulus and Griffith energy release rate, assuming that fractures propagate in the toughness-dominated regime. Our study shows that the variance and the spatial covariance of the mechanical properties are controlling factors in the tortuousness of the fracture paths. We characterize the deviation of fracture paths from the homogenous case statistically, and conclude that the maximum deviation grows linearly with the distance from the injection point. Additionally, fracture path deviations seem to be normally distributed, suggesting that fracture propagation in the toughness-dominated regime may be described as a random walk.

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

Probabilistic fracture mechanics applied for DHC assessment in the cool-down transients for CANDU pressure tubes

Energy Technology Data Exchange (ETDEWEB)

Radu, Vasile, E-mail: vasile.radu@nuclear.ro [Institute for Nuclear Research Pitesti, 1st Campului Street, 115400 Mioveni, Arges, P.O. Box 78, Mioveni (Romania); Roth, Maria [Institute for Nuclear Research Pitesti, 1st Campului Street, 115400 Mioveni, Arges, P.O. Box 78, Mioveni (Romania)

2012-12-15

For CANDU pressure tubes made from Zr-2.5%Nb alloy, the mechanism called delayed hydride cracking (DHC) is widely recognized as main mechanism responsible for crack initiation and propagation in the pipe wall. Generation of some blunt flaws at the inner pressure tube surface during refueling by fuel bundle bearing pad or by debris fretting, combined with hydrogen/deuterium up-take (20-40 ppm) from normal corrosion process with coolant, may lead to crack initiation and growth. The process is governed by hydrogen hysteresis of terminal solid solubility limits in Zirconium and the diffusion of hydrogen atoms in the stress gradient near to a stress spot (flaw). Creep and irradiation growth under normal operating conditions promote the specific mechanisms for Zirconium alloys, which result in circumferential expansion, accompanied by wall thinning and length increasing. These complicate damage mechanisms in the case of CANDU pressure tubes that are also are affected by irradiation environment in the reactor core. The structural integrity assessment of CANDU fuel channels is based on the technical requirements and methodology stated in the Canadian Standard N285.8. Usually it works with fracture mechanics principles in a deterministic manner. However, there are inherent uncertainties from the in-service inspection, which are associated with those from material properties determination; therefore a necessary conservatism in deterministic evaluation should be used. Probabilistic approach, based on fracture mechanics principle and appropriate limit state functions defined as fracture criteria, appears as a promising complementary way to evaluate structural integrity of CANDU pressure tubes. To perform this, one has to account for the uncertainties that are associated with the main parameters for pressure tube assessment, such as: flaws distribution and sizing, initial hydrogen concentration, fracture toughness, DHC rate and dimensional changes induced by long term

Monteggia fracture dislocation equivalents - analysis of eighteen cases treated by open reduction and internal fixation

Directory of Open Access Journals (Sweden)

Singh Ajay Pal

2012-02-01

Full Text Available 【Abstract】 Objective: Monteggia fracture dislocation equivalent, though already described by Bado, is still an unclassified entity. We aimed to retrospectively analyze 18 cases of Monteggia variants and discuss the injury mechanisms, management, and outcome along with a review of the literature. Methods: A retrospective record of Monteggia fracture dislocation (2003-2008 was reviewed from medical record department of our institute. Classic Monteggia fracture dislocation, children below 12 years or adults over 50 years, as well as open grade II & III cases were excluded from this study. Monteggia variant inclusion criteria included fracture of the proximal ulna together with a fracture of the radial head or neck and skeletal maturity. Totally 26 patients were identified with Monteggia variants and 18 were available for follow-up, including 11 males and 7 females with the mean age of 35 years. The ulna fracture was treated by compression plating along with tension band wiring. Radial head/neck was reconstructed in 12 patients while excised in 6 patients. Results: Follow-up ranged from 1-4 years, mean 2.6 years. Patients were assessed clinicoradiologically. Mayo Elbow Performance Score was employed to assess the outcomes. At final follow-up, the results were excellent in 10 patients, good in 4, fair in 2 and poor in 2. Mean range of motion of the elbow was 20°, 116°, 50° and 55° for extension, flexion, pronation and supination, respectively. Two patients had complications in the form of heterotopic ossification and stiffness of the elbow. One nonunion ulna, primarily treated by tension band wiring, was managed by refixation with locking reconstruction plate and bone grafting. Bone grafting was only required in this patient for nonunion. Another patient had implants removed on his request. The results in our series closely correlated with extent of intraarticular damage, coronoid fracture and comminuted fractures. Conclusions: Monteggia

Epidemiology of rib fractures in older men: Osteoporotic Fractures in Men (MrOS) prospective cohort study.

Science.gov (United States)

Barrett-Connor, Elizabeth; Nielson, Carrie M; Orwoll, Eric; Bauer, Douglas C; Cauley, Jane A

2010-03-15

To study the causes and consequences of radiologically confirmed rib fractures (seldom considered in the context of osteoporosis) in community dwelling older men. Prospective cohort study (Osteoporotic Fractures in Men (MrOS) Study). 5995 men aged 65 or over recruited in 2000-2 from six US sites; 99% answered mailed questionnaires about falls and fractures every four months for a mean 6.2 (SD 1.3) year follow-up. New fractures validated by radiology reports; multivariate Cox proportional hazard ratios were used to evaluate factors independently associated with time to incident rib fracture; associations between baseline rib fracture and incident hip and wrist fracture were also evaluated. The incidence of rib fracture was 3.5/1000 person years, and 24% (126/522) of all incident non-spine fractures were rib fractures. Nearly half of new rib fractures (48%; n=61) followed falling from standing height or lower. Independent risk factors for an incident rib fracture were age 80 or above, low bone density, difficulty with instrumental activities of daily living, and a baseline history of rib/chest fracture. Men with a history of rib/chest fracture had at least a twofold increased risk of an incident rib fracture (adjusted hazard ratio 2.71, 95% confidence interval 1.86 to 3.95), hip fracture (2.05, 1.33 to 3.15), and wrist fracture (2.06, 1.14 to 3.70). Only 14/82 of men reported being treated with bone specific drugs after their incident rib fracture. Rib fracture, the most common incident clinical fracture in men, was associated with classic risk markers for osteoporosis, including old age, low hip bone mineral density, and history of fracture. A history of rib fracture predicted a more than twofold increased risk of future fracture of the rib, hip, or wrist, independent of bone density and other covariates. Rib fractures should be considered to be osteoporotic fractures in the evaluation of older men for treatment to prevent future fracture.

Predictive factors determining outcomes in pulseless limb in paediatric supracondylar fractures of humerus.

Science.gov (United States)

Chaturvedi, Hemant; Khanna, Vikram; Bhargava, Rakesh; Vaishya, Raju

2018-03-01

Amongst all the complications associated with paediatric supracondylar humerus fractures, significant vascular injury is reported in only 1% cases, of which, less than 1% develop Volkmann's ischemic contracture. This study evaluates factors, like delay in presentation of the injury, limb perfusion and pulse, in determining functional outcome in a supracondylar humerus fractures with pulseless limb. Twenty-one paediatric patients with a pulseless supracondylar humerus fracture presenting from 2012 to 2014 were included. The patients were divided into 3 groups with Group A (pulse returned post-reduction, n = 13), Group B (pink pulseless hand, n = 7) and Group C (white pulseless hand, n = 1). 11 patients in group A and 4 patients in Group B presented within 6 h. of injury while the remaining patients presented after 6 h. The primary outcome was vascular status as indicated by radial pulse and perfusion, and secondary outcomes included functional parameters assessed with Mayo Elbow Performance Score and Flynn criteria. Mean peripheral SpO2 in Group A patients was higher than Group B and Group C had a non-recordable oxygen saturation. Mean capillary refill time was more in Group A than Group B whereas in Group C patient had blanching and no capillary refill was seen. Mean Mayo Elbow Performance Score of Group A patients was highest as compared to Group B and Group C. Patients presenting within 6 h. of injury had a higher mean Mayo Elbow Performance score as compared to the patients presenting after 6 h of injury. Functional outcome as measured by Flynn Criteria was excellent in 13 patients. 6 patients had a good, 2 had fair outcome. A moderate negative corrélation (R = -0.5798) was seen between the time elapsed from the injury and the Mayo Elbow Performance score. Duration to presentation since injury, limb perfusion and presence of peripheral pulses seem to be important predictive factors determining the outcomes in pulseless supracondylar fracture humerus.

Analysis of fracture patterns and local stress field variations in fractured reservoirs

Science.gov (United States)

Deckert, Hagen; Drews, Michael; Fremgen, Dominik; Wellmann, J. Florian

2010-05-01

A meaningful qualitative evaluation of permeabilities in fractured reservoirs in geothermal or hydrocarbon industry requires the spatial description of the existing discontinuity pattern within the area of interest and an analysis how these fractures might behave under given stress fields. This combined information can then be used for better estimating preferred fluid pathway directions within the reservoir, which is of particular interest for defining potential drilling sites. A description of the spatial fracture pattern mainly includes the orientation of rock discontinuities, spacing relationships between single fractures and their lateral extent. We have examined and quantified fracture patterns in several outcrops of granite at the Costa Brava, Spain, and in the Black Forest, Germany, for describing reservoir characteristics. For our analysis of fracture patterns we have used photogrammetric methods to create high-resolution georeferenced digital 3D images of outcrop walls. The advantage of this approach, compared to conventional methods for fracture analysis, is that it provides a better 3D description of the fracture geometry as the entity of position, extent and orientation of single fractures with respect to their surrounding neighbors is conserved. Hence for instance, the method allows generating fracture density maps, which can be used for a better description of the spatial distribution of discontinuities in a given outcrop. Using photogrammetric techniques also has the advantage to acquire very large data sets providing statistically sound results. To assess whether the recorded discontinuities might act as fluid pathways information on the stress field is needed. A 3D model of the regional tectonic structure was created and the geometry of the faults was put into a mechanical 3D Boundary Element (BE) Model. The model takes into account the elastic material properties of the geological units and the orientation of single fault segments. The

Intensely irradiated steel components: Plastic and fracture properties, and a new concept of structural design criteria for assuring the structural integrity

International Nuclear Information System (INIS)

Suzuki, Kazuhiko; Jitsukawa, Shiro; Okubo, Nariaki; Takada, Fumiki

2010-01-01

In order to develop a systematic and reasonable concept assuring the structural integrity of components under intense neutron irradiation, two basic tensile properties, true stress-true strain (TS-TS) curves and fracture strain, were investigated on an austenitic stainless steel and martensitic steel. Application of Swift equation is confirmed to a large plastic strain range of TS-TS curves. Fracture strain ε f data were well correlated as ε f + ε 0 = const. where ε 0 is the pre-strain representing the irradiation hardening. Based on those formulations and available experimental information, several critical issues to be dealt with in developing the concept were identified possible reduction in ductility, significant change in mechanical properties, remarkable cyclic softening and other unique cyclic properties observed during a high-cycle fatigue testing, and the redundancy of the plastic collapse concept to bending. Existing structural codes are all based on the assumption that there will be no significant changes in mechanical properties during operation, and of high ductility. Therefore, a new concept for assuring structural integrity is required for application not only to components with high ductility but also components with reduced ductility. First, potential failure modes were identified, and a new and systematic concept was proposed for preventing these modes of failure, introducing a new concept of categorizing the loadings by stability of deformation process to fracture (as type F and M loadings). Based on the basic concept, a detailed concept of how to protect against ductile fracture was given, and loading type-dependent limiting parameters were set. Finally, application of the detailed concept was presented, especially on determination of loading type (in numerical approach, the formulation of TS-TS curves and fracture strain derived above are needed), and on how to determine the limiting parameters as allowable limits. Experiments were done to

Intensely irradiated steel components: Plastic and fracture properties, and a new concept of structural design criteria for assuring the structural integrity

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Kazuhiko, E-mail: suzuki.kazuhiko@jaea.go.j [Japan Atomic Energy Agency, Nuclear Science and Engineering Directorate, 2-4 Shirane, Shirakata, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 (Japan); Jitsukawa, Shiro; Okubo, Nariaki [Japan Atomic Energy Agency, Nuclear Science and Engineering Directorate, 2-4 Shirane, Shirakata, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 (Japan); Takada, Fumiki [Japan Atomic Energy Agency, Department of JMTR Operation, Narita-cho, Oarai-machi, Higashi-ibaraki-gun, Ibaraki-ken 311-1393 (Japan)

2010-06-15

In order to develop a systematic and reasonable concept assuring the structural integrity of components under intense neutron irradiation, two basic tensile properties, true stress-true strain (TS-TS) curves and fracture strain, were investigated on an austenitic stainless steel and martensitic steel. Application of Swift equation is confirmed to a large plastic strain range of TS-TS curves. Fracture strain epsilon{sub f} data were well correlated as epsilon{sub f} + epsilon{sub 0} = const. where epsilon{sub 0} is the pre-strain representing the irradiation hardening. Based on those formulations and available experimental information, several critical issues to be dealt with in developing the concept were identified possible reduction in ductility, significant change in mechanical properties, remarkable cyclic softening and other unique cyclic properties observed during a high-cycle fatigue testing, and the redundancy of the plastic collapse concept to bending. Existing structural codes are all based on the assumption that there will be no significant changes in mechanical properties during operation, and of high ductility. Therefore, a new concept for assuring structural integrity is required for application not only to components with high ductility but also components with reduced ductility. First, potential failure modes were identified, and a new and systematic concept was proposed for preventing these modes of failure, introducing a new concept of categorizing the loadings by stability of deformation process to fracture (as type F and M loadings). Based on the basic concept, a detailed concept of how to protect against ductile fracture was given, and loading type-dependent limiting parameters were set. Finally, application of the detailed concept was presented, especially on determination of loading type (in numerical approach, the formulation of TS-TS curves and fracture strain derived above are needed), and on how to determine the limiting parameters as

Improved criteria for the repair of fabrication flaws

International Nuclear Information System (INIS)

Doctor, S.R.; Schuster, G.J.; Simonen, F.A.

2003-01-01

Section III of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code for nuclear power plant components requires radiographic examinations (RT) of welds and requires repairs for RT indications that exceed code acceptable sizes. This paper describes research that has generated data on welding flaws, which indicated that the largest flaws occur in repaired welds. The fabrication flaws were detected in material removed from cancelled nuclear power plants using high sensitivity Nondestructive Examination (NDE) and validated by complementary NDE and destructive testing. Evidence suggests that repairs are often for small and benign RT indications at locations buried within the vessel or pipe wall. Probabilistic fracture mechanics calculations are described in this paper to predict the increases in vessel failure probabilities caused by the repair-induced flaws. Calculations address failures of embrittled vessel welds for pressurized thermal shock (PTS) transients. In this case small flaws, which are relatively common, can cause brittle fracture, such that the rarely encountered repair flaws of large sizes gave only modestly increased failure probabilities. The paper recommends the use of more discriminating ultrasonic examinations in place of RT examinations along with repair criteria based on a fitness-for-purpose approach that minimize the number of unjustified repairs. (author)

Radiological classification of mandibular fractures

International Nuclear Information System (INIS)

Mihailova, H.

2009-01-01

Mandibular fractures present the biggest part (up to 97%) of the facial bone fractures. Method of choice for diagnosing of mandibular fractures is conventional radiography. The aim of the issue is to present an unified radiological classification of mandibular fractures for the clinical practice. This classification includes only those clinical symptoms of mandibular fracture which could be radiologically objectified: exact anatomical localization (F1-F6), teeth in fracture line (Ta,Tb), grade of dislocation (D I, D II), occlusal disturbances (O(+), O(-)). Radiological symptoms expressed by letter and number symbols are systematized in a formula - FTDO of mandibular fractures similar to TNM formula for tumours. FTDO formula expresses radiological diagnose of each mandibular fracture but it doesn't include neither the site (left or right) of the fracture, nor the kind and number of fractures. In order to express topography and number of fractures the radiological formula is transformed into a decimal fraction. The symbols (FTD) of right mandible fracture are written in the numerator and those of the left site - in the denominator. For double and multiple fractures between the symbols for each fracture we put '+'. Symbols for occlusal disturbances are put down opposite, the fractional line. So topographo-anatomical formula (FTD/FTD)xO is formed. In this way the whole radiological information for unilateral, bilateral, single or multiple fractures of the mandible is expressed. The information in the radiological topography anatomic formula, resp. from the unified topography-anatomic classification ensures a quick and exact X-ray diagnose of mandibular fracture. In this way contributes to get better, make easier and faster X-ray diagnostic process concerning mandibular fractures. And all these is a precondition for prevention of retardation of the diagnosis mandibular fracture. (author)

Fracture mechanics performance of UF6 containers

International Nuclear Information System (INIS)

Gonzalez, M.E.; Iorio, A.F.; Crespi, J.C.

1993-01-01

The main purpose of this work was to determine the fracture mechanics performance of UF 6 transport cylinders type ANSI N14.1.30B, which was made from ASTM A 516 Grade 70 steel. It was assumed an internal surface axial crack subjected to stresses due to service, proof and transport accident loads. The KUMAR-GERMAN-SHIH elastoplastic methodology gave adequate results for crack depth estimation. The results validate the leak-before-break criteria for service and proof conditions but not for accident ones. In the last case a non-destructive examination must be done in order to assure the absence of defects larger than one third of the cylinder wall thickness. (Author)

An unusual stress fracture: Bilateral posterior longitudinal stress fracture of tibia.

Science.gov (United States)

Malkoc, Melih; Korkmaz, Ozgur; Ormeci, Tugrul; Oltulu, Ismail; Isyar, Mehmet; Mahirogulları, Mahir

2014-01-01

Stress fractures (SF) occur when healthy bone is subjected to cyclic loading, which the normal carrying range capacity is exceeded. Usually, stress fractures occur at the metatarsal bones, calcaneus, proximal or distal tibia and tends to be unilateral. This article presents a 58-year-old male patient with bilateral posterior longitudinal tibial stress fractures. A 58 years old male suffering for persistent left calf pain and decreased walking distance for last one month and after imaging studies posterior longitudinal tibial stress fracture was detected on his left tibia. After six months the patient was admitted to our clinic with the same type of complaints in his right leg. All imaging modalities and blood counts were performed and as a result longitudinal posterior tibial stress fractures were detected on his right tibia. Treatment of tibial stress fracture includes rest and modified activity, followed by a graded return to activity commensurate with bony healing. We have applied the same treatment protocol and our results were acceptable but our follow up time short for this reason our study is restricted for separate stress fractures of the posterior tibia. Although the main localization of tibial stress fractures were unilateral, anterior and transverse pattern, rarely, like in our case, the unusual bilateral posterior localization and longitudinal pattern can be seen. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Fracture under mixed-mode I+II of the austenitic stainless steel 316L

International Nuclear Information System (INIS)

Jeon, K.L.

1993-08-01

The stability of cracks under mixed-mode l+ll in an aged stainless steel type 316L is investigated using four-points bent specimens. The formulas of the bending moment, the shearing force, the mode mixity, the limit load and the J estimations are established and compared with the numerical results from elastoplastic finite element calculations. From the experimental and numerical tests results, the application and the validation of the R6 method and various local criteria (Beremin, McClintock, Guennouni-Francois and Lemaitre models) are carried out. For the R6 method, it is noted that the FAD (Failure Assessment Diagram) is nearly independent of the loading mode and the specimen geometry. The FAD of the option 1 is conservative for all the test results, but the option 3 seems to be non-conservative, especially in the cases near to the mode I. This apparent non-conservatism is probably due to the different definition of the crack initiation of the CT specimens and the 4-point bend specimens. According to the applied local criteria, the values of the damage variables at crack initiation are sufficiently stable, particularly for the Beremin model and the Guennouni-Francois model but not in the cases nearer to the mode I. The use of these local criteria is questionable in the case of axisymmetric notched specimens because of the influence of the fracture of transformed ferrite. A fractographic investigation is also discussed for different fracture modes. (author). 85 refs., 99 figs., 14 tabs

Application of the Mandible Injury Severity Score to Pediatric Mandibular Fractures.

Science.gov (United States)

Swanson, Edward W; Susarla, Srinivas M; Ghasemzadeh, Ali; Mundinger, Gerhard S; Redett, Richard J; Tufaro, Anthony P; Manson, Paul N; Dorafshar, Amir H

2015-07-01

The Mandible Injury Severity Score (MISS) has been used to evaluate adult mandibular fractures. The purpose of this study was to evaluate the MISS in a cohort of pediatric patients. This was a retrospective study of pediatric patients treated for mandibular fractures over a 20-year period. Patients were included if they had computed tomographic imaging available for review and had at least 1 post-treatment visit. The primary predictor variable was the MISS. Secondary predictors were demographic and injury-associated factors. The outcome was treatment-associated complications. Descriptive, bivariate, and multiple logistic regression statistics were computed. One hundred sixteen patients with mandibular fractures were identified; 73 (62.9%) met the inclusion criteria. The sample's mean age was 8.5 ± 4.1 years; 44% were girls. Motor vehicle collisions (60%) and falls (15.1%) were the most common mechanisms. More than 50% of patients had an extra-mandibular injury. The mean MISS was 13.5 ± 7.8. Forty-five percent of the sample underwent open reduction and internal fixation. Complications were noted in 20.5% of patients, of which malocclusion was the most common (8.2%). Increasing MISS was associated with complications (P pediatric patients with mandibular fractures, increased severity of injury is associated with complications, even after controlling for the effects of multiple confounders, including open treatment. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

A STUDY ON PROXIMAL HUMERAL FRACTURES STABILISED WITH PHILOS PLATE

Directory of Open Access Journals (Sweden)

Praveen Sivakumar K

2017-02-01

Full Text Available BACKGROUND Techniques for treating complex proximal humeral fractures vary and include fixations using tension bands, percutaneous pins, bone suture, T-plates, intramedullary nails, double tubular plates, hemiarthroplasty, plant tan humerus fixator plates, Polaris nails and blade plates. Complications of these techniques include cutout or back out of the screws and plates, avascular necrosis, nonunion, malunion, nail migration, rotator cuff impairment and impingement syndromes. Insufficient anchorage from conventional implants may lead to early loosening and failure, especially in osteoporotic bones. In general, nonoperative treatment of displaced three and four-part fractures of the proximal humerus leads to poor outcome due to intraarticular nature of injury and inherent instability of the fragments. Comminuted fractures of the proximal humerus are at risk of fixation failure, screw loosening and fracture displacement. Open reduction and internal fixation with conventional plate and screws has been associated with unacceptably high incidence of screw pull out. PHILOS (the proximal humeral internal locking system plate is an internal fixation system that enables angled stabilisation with multiple interlocking screws for fractures of the proximal humerus. MATERIALS AND METHODS 30 patients with proximal humerus fractures who were admitted in the Department of Orthopaedics, Government General Hospital, Kakinada, during the period November 2014 - November 2016 were taken up for study according to inclusion criteria. All patients were treated with PHILOS plate. These proximal humerus fractures were classified according to Neer’s classification. Patients were followed up at 6 weeks, 12 weeks and 6 months’ interval. Functional outcomes for pain, range of motion and muscle power and function were assessed using the Constant-Murley scoring system. Collected data analysed with independent t-test and ANNOVA test. RESULTS The outcome of the study was 1

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 increase...

TIBIAL SHAFT FRACTURES.

Science.gov (United States)

Kojima, Kodi Edson; Ferreira, Ramon Venzon

2011-01-01

The long-bone fractures occur most frequently in the tibial shaft. Adequate treatment of such fractures avoids consolidation failure, skewed consolidation and reoperation. To classify these fractures, the AO/OTA classification method is still used, but it is worthwhile getting to know the Ellis classification method, which also includes assessment of soft-tissue injuries. There is often an association with compartmental syndrome, and early diagnosis can be achieved through evaluating clinical parameters and constant clinical monitoring. Once the diagnosis has been made, fasciotomy should be performed. It is always difficult to assess consolidation, but the RUST method may help in this. Radiography is assessed in two projections, and points are scored for the presence of the fracture line and a visible bone callus. Today, the dogma of six hours for cleaning the exposed fracture is under discussion. It is considered that an early start to intravenous antibiotic therapy and the lesion severity are very important. The question of early or late closure of the lesion in an exposed fracture has gone through several phases: sometimes early closure has been indicated and sometimes late closure. Currently, whenever possible, early closure of the lesion is recommended, since this diminishes the risk of infection. Milling of the canal when the intramedullary nail is introduced is still a controversial subject. Despite strong personal positions in favor of milling, studies have shown that there may be some advantage in relation to closed fractures, but not in exposed fractures.

Treatment of mandibular symphyseal fracture combined with dislocated intracapsular condylar fractures.

Science.gov (United States)

Xu, Xiaofeng; Shi, Jun; Xu, Bing; Dai, Jiewen; Zhang, Shilei

2015-03-01

To evaluate the treatment methods of mandibular symphyseal fracture combined with dislocated intracapsular condylar fractures (MSF&DICF) and to compare the effect of different treatment methods of condylar fractures. Twenty-eight patients with MSF&DICF were included in this study. Twenty-two sites were treated by open reduction, and all the medial condylar fragments were fixed with titanium screws; whereas the other 22 sites underwent close treatment. The surgical effect between these 2 groups was compared based on clinical examination and radiographic examination results. Seventeen of 22 condyle fractures were repositioned in the surgery group, whereas 4 of 22 condyle fractures were repositioned in the close treatment group. Statistical difference was observed between these 2 groups (P condyle fractures should be treated by surgical reduction with the maintenance of the attachment of lateral pterygoid muscle, which is beneficial to repositioning the dislocated condyle to its original physiological position, to closure of the mandibular lingual gap, to restore the mandibular width.

Classification of Porcine Cranial Fracture Patterns Using a Fracture Printing Interface,.

Science.gov (United States)

Wei, Feng; Bucak, Serhat Selçuk; Vollner, Jennifer M; Fenton, Todd W; Jain, Anil K; Haut, Roger C

2017-01-01

Distinguishing between accidental and abusive head trauma in children can be difficult, as there is a lack of baseline data for pediatric cranial fracture patterns. A porcine head model has recently been developed and utilized in a series of studies to investigate the effects of impact energy level, surface type, and constraint condition on cranial fracture patterns. In the current study, an automated pattern recognition method, or a fracture printing interface (FPI), was developed to classify cranial fracture patterns that were associated with different impact scenarios documented in previous experiments. The FPI accurately predicted the energy level when the impact surface type was rigid. Additionally, the FPI was exceedingly successful in determining fractures caused by skulls being dropped with a high-level energy (97% accuracy). The FPI, currently developed on the porcine data, may in the future be transformed to the task of cranial fracture pattern classification for human infant skulls. © 2016 American Academy of Forensic Sciences.

Hydrajet fracturing: an effective method for placing many fractures in openhole horizontal wells

Energy Technology Data Exchange (ETDEWEB)

Surjaatmadja, J. B.; Grundmann, S. R.; McDaniel, B.; Deeg, W. F. J.; Brumley, J. L.; Swor, L. C.

1998-12-31

A new method for openhole horizontal well fracturing that combines hydrajetting and fracturing techniques, which was developed on the basis of Bernoulli`s theorem, is described. This theorem has been effectively proven in many applications such as jet pumps, additive injection systems and jet aircraft engines. By using this method, operators can position a jetting tool, without the use of sealing elements, at the exact point where fracture is required. The method also permits the use of multiple fractures in the same well, which can be spaced evenly or unevenly as prescribed by the fracturing program. Damage can be avoided by placing hundreds of small fractures in a long horizontal section, or operators can use acid and/or propped sand techniques to place a combination of two fracture types in the well. The paper describes the basic principles of horizontal hydrajet fracturing, and elements of a laboratory model which was developed to demonstrate the effectiveness of the method.

Characterisation of hydraulically-active fractures in a fractured ...

African Journals Online (AJOL)

... in the initial stage of a site investigation to select the optimal site location or to evaluate the hydrogeological properties of fractures in underground exploration studies, such as those related geothermal reservoir evaluation and radioactive waste disposal. Keywords: self-potential method, hydraulically-conductive fractures, ...

Micromechanics modelling of ductile fracture

CERN Document Server

Chen, Zengtao

2013-01-01

This book summarizes research advances in micromechanics modelling of ductile fractures made in the past two decades. The ultimate goal of this book is to reach manufacturing frontline designers and materials engineers by providing a user-oriented, theoretical background of micromechanics modeling. Accordingly, the book is organized in a unique way and presents a vigorous damage percolation model developed by the authors over the last ten years. This model overcomes almost all difficulties of the existing models and can be used to completely accommodate ductile damage development within a single, measured microstructure frame. Related void damage criteria including nucleation, growth and coalescence are then discussed in detail: how they are improved, when and where they are used in the model, and how the model performs in comparison with the existing models. Sample forming simulations are provided to illustrate the model’s performance.

Fracture propagation in sandstone and slate – Laboratory experiments, acoustic emissions and fracture mechanics

Directory of Open Access Journals (Sweden)

Ferdinand Stoeckhert

2015-06-01

Full Text Available Fracturing of highly anisotropic rocks is a problem often encountered in the stimulation of unconventional hydrocarbon or geothermal reservoirs by hydraulic fracturing. Fracture propagation in isotropic material is well understood but strictly isotropic rocks are rarely found in nature. This study aims at the examination of fracture initiation and propagation processes in a highly anisotropic rock, specifically slate. We performed a series of tensile fracturing laboratory experiments under uniaxial as well as triaxial loading. Cubic specimens with edge lengths of 150 mm and a central borehole with a diameter of 13 mm were prepared from Fredeburg slate. An experiment using the rather isotropic Bebertal sandstone as a rather isotropic rock was also performed for comparison. Tensile fractures were generated using the sleeve fracturing technique, in which a polymer tube placed inside the borehole is pressurized to generate tensile fractures emanating from the borehole. In the uniaxial test series, the loading was varied in order to observe the transition from strength-dominated fracture propagation at low loading magnitudes to stress-dominated fracture propagation at high loading magnitudes.

Cannulated screw and cable are superior to modified tension band in the treatment of transverse patella fractures.

Science.gov (United States)

Tian, Yun; Zhou, Fang; Ji, Hongquan; Zhang, Zhishan; Guo, Yan

2011-12-01

Although the modified tension band technique (eg, tension band supplemented by longitudinal Kirschner wires) has long been the mainstay for fixation of transverse fractures of the patella, it has shortcomings, such as bad reduction, loosening of implants, and skin irritation. We conducted a retrospective comparison of the modified tension band technique and the titanium cable-cannulated screw tension band technique. We retrospectively reviewed 101 patients aged 22 to 85 years (mean, 56.6 years) with AO/OTA 34-C1 fractures (n = 68) and 34-C2 fractures (n = 33). Fifty-two patients were in the modified tension band group and 49 were in the titanium cable-cannulated screw tension band group. Followup was at least 1 year (range, 1-3 years). Comparison criteria were fracture reduction, fracture healing time, and the Iowa score for knee function. The titanium cable-cannulated screw tension band group showed improved fracture reduction, reduced healing time, and better Iowa score, compared with the modified tension band group. In the modified tension band group, eight patients experienced wire migration, three of these requiring a second operation. There were no complications in the titanium cable-cannulated screw tension band group. The titanium cable-cannulated screw tension band technique showed superior results and should be considered as an alternative method for treatment of transverse patellar fractures. Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Rib Fractures

Science.gov (United States)

... Video) Achilles Tendon Tear Additional Content Medical News Rib Fractures By Thomas G. Weiser, MD, MPH, Associate Professor, ... Tamponade Hemothorax Injury to the Aorta Pulmonary Contusion Rib Fractures Tension Pneumothorax Traumatic Pneumothorax (See also Introduction to ...

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 

Orbital wall fractures

International Nuclear Information System (INIS)

Iinuma, Toshitaka; Ishio, Ken-ichirou; Yoshinami, Hiroyoshi; Kuriyama, Jun-ichi; Hirota, Yoshiharu.

1993-01-01

A total of 59 cases of mild facial fractures (simple orbital wall fractures, 34 cases, other facial fractures, 25 cases) with the clinical suspects of orbital wall fractures were evaluated both by conventional views (Waters' and Caldwell views) and coronal CT scans. Conventional views were obtained, as an average, after 4 days and CT after 7 days of injuries. Both the medial wall and the floor were evaluated at two sites, i.e., anterior and posterior. The ethmoid-maxillary plate was also included in the study. The degree of fractures was classified as, no fractures, fractures of discontinuity, dislocation and fragmentation. The coronal CT images in bone window condition was used as reference and the findings were compared between conventional views and CT. The correct diagnosis was obtained as follows: orbital floor (anterior, 78%, posterior, 73%), medial orbital wall (anterior, 72%, posterior, 72%) and ethmoid-maxillary plate (64%). The false positive diagnosis was as follows: orbital floor (anterior only, 13%), medial orbital wall (anterior only, 7%) and ethmoid-maxillary plate (11%). The false negative diagnosis was as follows: orbital floor (anterior, 9%, posterior, 10%), medial orbital wall (anterior, 21%, posterior, 28%) and ethmoid-maxillary plate (21%). The results were compared with those of others in the past. (author)

Fracture toughness requirements of reactor vessel material in evaluation of the safety analysis report of nuclear power plants

International Nuclear Information System (INIS)

Widia Lastana Istanto

2011-01-01

Fracture toughness requirements of reactor vessel material that must be met by applicants for nuclear power plants construction permit has been investigated in this paper. The fracture toughness should be described in the Safety Analysis Reports (SARs) document that will be evaluated by the Nuclear Energy Regulatory Agency (BAPETEN). Because BAPETEN does not have a regulations or standards/codes regarding the material used for the reactor vessel, especially in the fracture toughness requirements, then the acceptance criteria that applied to evaluate the fracture toughness of reactor vessel material refers to the regulations/provisions from the countries that have been experienced in the operation of nuclear power plants, such as from the United States, Japan and Korea. Regulations and standards used are 10 CFR Part 50, ASME and ASTM. Fracture toughness of reactor vessel materials are evaluated to ensure compliance of the requirements and provisions of the Regulatory Body and the applicable standards, such as ASME or ASTM, in order to assure a reliability and integrity of the reactor vessels as well as providing an adequate safety margin during the operation, testing, maintenance, and postulated accident conditions over the reactor vessel lifetime. (author)

Multi-zone coupling productivity of horizontal well fracturing with complex fracture networks in shale gas reservoirs

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Weiyao Zhu

2018-02-01

Full Text Available In this paper, a series of specific studies were carried out to investigate the complex form of fracture networks and figure out the multi-scale flowing laws of nano/micro pores–complex fracture networks–wellbore during the development of shale reservoirs by means of horizontal well fracturing. First, hydraulic fractures were induced by means of Brazilian splitting tests. Second, the forms of the hydraulic fractures inside the rock samples were observed by means of X-ray CT scanning to measure the opening of hydraulic fractures. Third, based on the multi-scale unified flowing model, morphological description of fractures and gas flowing mechanism in the matrix–complex fracture network–wellbore, the productivity equation of single-stage horizontal well fracturing which includes diffusion, slipping and desorption was established. And fourthly, a productivity prediction model of horizontal well multi-stage fracturing in the shale reservoir was established considering the interference between the multi-stage fracturing zones and the pressure drop in the horizontal wellbore. The following results were obtained. First, hydraulic fractures are in the form of a complex network. Second, the measured opening of hydraulic fractures is in the range of 4.25–453 μm, averaging 112 μm. Third, shale gas flowing in different shapes of fracture networks follows different nonlinear flowing laws. Forth, as the fracture density in the strongly stimulated zones rises and the distribution range of the hydraulic fractures in strongly/weakly stimulated zones enlarges, gas production increases gradually. As the interference occurs in the flowing zones of fracture networks between fractured sections, the increasing amplitude of gas production rates decreases. Fifth, when the length of a simulated horizontal well is 1500 m and the half length of a fracture network in the strongly stimulated zone is 100 m, the productivity effect of stage 10 fracturing is the