Serum albumin and total lymphocyte count as predictors of outcome in hip fractures.

LENUS (Irish Health Repository)

O'Daly, Brendan J

2012-02-01

BACKGROUND & AIMS: Hip fractures are a significant cause of mortality and morbidity in the elderly. Malnutrition is a significant contributor to this, however no consensus exists as to the detection or management of this condition. We hypothesise that results of admission serum albumin and total lymphocyte count (TLC), as markers of Protein Energy Malnutrition (PEM) can help predict clinical outcome in hip fracture patients aged over 60 years. METHODS: This retrospective study evaluated the nutritional status of patients with hip fractures using albumin and TLC assays and analysed their prognostic relevance. Clinical outcome parameters studied were delay to operation, duration of in-patient stay, re-admission and in-patient, 3- and 12-month mortality. RESULTS: Four hundred and fifteen hip fracture patients were evaluated. Survival data were available for 377 patients at 12 months. In-hospital mortality for PEM patients was 9.8%, compared with 0% for patients without. Patients with PEM had a higher 12-month mortality compared to patients who had normal values of both laboratory parameters (Odds Ratio 4.6; 95% CI: 1.0-21.3). Serum albumin (Hazard Ratio 0.932, 95% CI: 0.9-1.0) and age (Hazard Ratio 1.04, 95% CI: 1.0-1.1) were found to be significant independent prognostic factors of mortality by Cox regression analysis. CONCLUSIONS: These results highlight the relevance of assessing the nutritional status of patients with hip fractures at the time of admission and emphasises the correlation between PEM and outcome in these patients.

Ground source energy in crystalline bedrock - increased energy extraction by using hydraulic fracturing in boreholes

Energy Technology Data Exchange (ETDEWEB)

Ramstad, Randi Kalstad

2004-11-01

The use of improved equipment and methodology can result in considerable reductions in the drilling costs for medium- to large sized ground source heat pump system in crystalline bedrock. The main point has been to use special techniques within hydraulic fracturing to create a larger heat exchange area in the bedrock, and thus a greater energy extraction per borehole. The energy extraction is based on circulating groundwater. Stimulation with hydraulic fracturing is a well known technique in order to improve borehole yields for drinking water-, oil-, and geothermal purposes. A procedure for injection of propping agents in selected borehole sections, and custom-made equipment for hydraulic fracturing in crystalline bedrock, a double packer, have been developed in this study. The propping agents are likely to ensure a permanent improvement of the hydraulic conductivity in a long-run perspective. In addition to a pre-test, a comprehensive test programme has been performed at each of the two pilot plants at Bryn and at the former property of Energiselskapet Asker og Baerum (EAB) in Baerum municipality outside Oslo, Norway. A total of 125 stimulations with hydraulic fracturing using water-only and hydraulic fracturing with injection of sand have been performed in 9 boreholes. Test pumping and geophysical logging (temperature, electrical conductivity, gamma radiation, optical televiewer and flow measurements) have been carried out in order to document the effect of the hydraulic fracturing. The pilot plants at Bryn and EAB, where the ground source heat pump systems are based on circulating groundwater, have demonstrated the short-period energy extraction, limitations and opportunities of the concept for hydraulic fracturing and increased energy extraction in different geological and hydrogeological areas. The bedrock at Bryn and EAB is characterized as a low-metamorphic sandstone and a nodular limestone, respectively. At Bryn, the five boreholes were organised with a

Nontraumatic tibial polyethylene insert cone fracture in mobile-bearing posterior-stabilized total knee arthroplasty

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Yohei Tanikake

2016-12-01

Full Text Available A 72-year-old male patient underwent mobile-bearing posterior-stabilized total knee arthroplasty for osteoarthritis. He experienced a nontraumatic polyethylene tibial insert cone fracture 27 months after surgery. Scanning electron microscopy of the fracture surface of the tibial insert cone suggested progress of ductile breaking from the posterior toward the anterior of the cone due to repeated longitudinal bending stress, leading to fatigue breaking at the anterior side of the cone, followed by the tibial insert cone fracture at the anterior side of the cone, resulting in fracture at the base of the cone. This analysis shows the risk of tibial insert cone fracture due to longitudinal stress in mobile-bearing posterior-stabilized total knee arthroplasty in which an insert is designed to highly conform to the femoral component.

Primary Total Hip Replacement for a Femoral Neck Fracture in a Below-Knee Amputee

OpenAIRE

Masmoudi, Karim; Rbai, H?di; Fradj, Ayman Ben; Sa?dena, Jecem; Boughattas, Anouar

2016-01-01

Introduction: Femoral neck fracture on amputated limb is an uncommon lesion and challenging to manage. Case Report: We report a case of a displaced neck fracture of the left femur in a 57-year-old female. She underwent at the age of the three a below-knee amputation of the ipsilateral limb for post traumatic ischemia. The fracture was managed by a total hip arthroplasty (THA), as a primary procedure. In this article we describe our experience of this unusual entity. Conclusion: Total hip arth...

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.

What is the earthquake fracture energy?

Science.gov (United States)

Di Toro, G.; Nielsen, S. B.; Passelegue, F. X.; Spagnuolo, E.; Bistacchi, A.; Fondriest, M.; Murphy, S.; Aretusini, S.; Demurtas, M.

2016-12-01

The energy budget of an earthquake is one of the main open questions in earthquake physics. During seismic rupture propagation, the elastic strain energy stored in the rock volume that bounds the fault is converted into (1) gravitational work (relative movement of the wall rocks bounding the fault), (2) in- and off-fault damage of the fault zone rocks (due to rupture propagation and frictional sliding), (3) frictional heating and, of course, (4) seismic radiated energy. The difficulty in the budget determination arises from the measurement of some parameters (e.g., the temperature increase in the slipping zone which constraints the frictional heat), from the not well constrained size of the energy sinks (e.g., how large is the rock volume involved in off-fault damage?) and from the continuous exchange of energy from different sinks (for instance, fragmentation and grain size reduction may result from both the passage of the rupture front and frictional heating). Field geology studies, microstructural investigations, experiments and modelling may yield some hints. Here we discuss (1) the discrepancies arising from the comparison of the fracture energy measured in experiments reproducing seismic slip with the one estimated from seismic inversion for natural earthquakes and (2) the off-fault damage induced by the diffusion of frictional heat during simulated seismic slip in the laboratory. Our analysis suggests, for instance, that the so called earthquake fracture energy (1) is mainly frictional heat for small slips and (2), with increasing slip, is controlled by the geometrical complexity and other plastic processes occurring in the damage zone. As a consequence, because faults are rapidly and efficiently lubricated upon fast slip initiation, the dominant dissipation mechanism in large earthquakes may not be friction but be the off-fault damage due to fault segmentation and stress concentrations in a growing region around the fracture tip.

Type III odontoid fractures: A subgroup analysis of complex, high-energy fractures treated with external immobilization

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Thomas E Niemeier

2018-01-01

Conclusions: Complex Type III odontoid fractures are distinctly different from low-energy injuries. In the current study, 21% of patients were unsuccessfully treated nonoperatively with external immobilization and required surgery. For complex Type III fractures, we recommend initial conservative treatment, while maintaining close monitoring throughout patient recovery and fracture union.

Primary total hip replacement for displaced subcapital fractures of the femur.

Science.gov (United States)

Taine, W H; Armour, P C

1985-03-01

The management of displaced subcapital fracture of the hip is still controversial because of the high incidence of complications after internal fixation or hemiarthroplasty. To avoid some of these complications we have used primary total hip replacement for independently mobile patients over 65 years of age. A total of 163 cases, operated on over four years, have been reviewed. There were relatively more dislocations after operation for fracture than after total replacement for arthritis, and these were associated with a posterior approach to the hip. Only seven revision operations have been required. Of 57 patients who were interviewed an average of 42 months after replacement, 62% had excellent or good results as assessed by the Harris hip score. All the others had major systemic disease which affected their assessment. This inadequacy of current systems of hip assessment is discussed. It is concluded that total hip replacement is the best management for a selected group of patients with this injury, and that further prospective studies are indicated.

Crack formation and fracture energy of normal and high strength ...

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

Abstract. The crack path through composite materials such as concrete depends on the mechanical interaction of inclusions with the cement-based matrix. Fracture energy depends on the deviations of a real crack from an idealized crack plane. Fracture energy and strain softening of normal, high strength, and self- ...

EPIDEMIOLOGICAL STUDY OF LOW ENERGY FRACTURES IN REPUBLIC OF ARMENIA

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S. Saakyan

2017-01-01

Full Text Available Until present no data was available inArmeniain respect of incidence of low energy fractures that are typical of osteoporotic locations which consequently did not allow to evaluate the scope of this problem across the country.Purpose of the study – to identify the incidence of low energy fractures in proximal femur, in distal forearm, in proximal humerus and in distal tibia across population ofArmenia aged 50 years and older.Materials and methods. An observing population study was performed in two regions of Armenia during 2011-2013 where the frequency of selected locations in cases of moderate trauma was identified. During 2011-2012 the information was collected based on traumatology service records adding in 2013 other sources including primary level of healthcare due to observed infrequent applications for medical help in cases of trauma. Results. In 2013 the incidence of proximal femur fractures in men was reported as 136 cases per 100 000 of population aged 50 years and older, in women – 201 cases per 100 000. At the same time only 57.7% of patients with proximal femur fractures were admitted to hospital. Distal forearm fractures incidence in men and women was observed correspondingly 56/100 000 and 176/100 000 cases, proximal humerus fractures – 39/100 000 and 86/100 000 cases and distal tibia fractures – 39/100 000 and 86/100 000 cases. The predicted annual number of proximal femur fracture in Armenia amounts to 2067 cases, distal forearm fractures – 1205, proximal humerus fractures – 640.Conclusion. Epidemiological data that was collected for the first time on low energy fractures incidence confirmed the acute osteoporosis issue inArmenia and revealed the problems in organization of medical care for the group of senior patients with injuries.

Fracture toughness and fracture surface energy of sintered uranium dioxide fuel pellets

International Nuclear Information System (INIS)

Kutty, T.R.G.; Chandrasekharan, K.N.; Panakkal, J.P.; Ghosh, J.K.

1987-01-01

The paper concerns the variation of fracture toughness Ksub(ic) and fracture surface energy γsub(s) in sintered uranium dioxide pellets in the density range 9.86 to 10.41 g cm -3 , using Vickers indentation technique. A minimum of four indentations were made on each pellet sample and the average crack length of each indentation and the hardness values were determined. The overall average crack-length datra and the data on volume fraction porosity in the pellets fitted a straight line, from which Ksub(ic) and γsub(s) were calculated. The fracture parameters of nonporous polycrystalline UO 2 , calculated from the experimental data, are presented in tabular form. (U.K.)

Age Related Macular Degeneration and Total Hip Replacement Due to Osteoarthritis or Fracture: Melbourne Collaborative Cohort Study.

Directory of Open Access Journals (Sweden)

Elaine W Chong

Full Text Available Osteoarthritis is the leading cause of total hip replacement, accounting for more than 80% of all total hip replacements. Emerging evidence suggests that osteoarthritis has a chronic inflammatory component to its pathogenesis similar to age-related macular degeneration. We evaluated the association between age-related macular degeneration and total hip replacement as proxy for severe osteoarthritis or fractured neck of femur in the Melbourne Collaborative Cohort Study. 20,744 participants had complete data on both age-related macular degeneration assessed from colour fundus photographs taken during 2003-2007 and total hip replacement. Total hip replacements due to hip osteoarthritis and fractured neck of femur during 2001-2011 were identified by linking the cohort records to the Australian Orthopedic Association National Joint Replacement Registry. Logistic regression was used to examine the association between age-related macular degeneration and risk of total hip replacement due to osteoarthritis and fracture separately, adjusted for confounders. There were 791 cases of total hip replacement for osteoarthritis and 102 cases of total hip replacement due to fractured neck of femur. After adjustment for age, sex, body mass index, smoking, and grouped country of birth, intermediate age-related macular degeneration was directly associated with total hip replacement for osteoarthritis (odds ratio 1.22, 95% CI 1.00-1.49. Late age-related macular degeneration was directly associated with total hip replacement due to fractured neck of femur (odds ratio 5.21, 95% CI2.25-12.02. The association between intermediate age-related macular degeneration and an increased 10-year incidence of total hip replacement due to osteoarthritis suggests the possibility of similar inflammatory processes underlying both chronic diseases. The association of late age-related macular degeneration with an increased 10-year incidence of total hip replacement due to fractured

Fracture Energy of High-Strength Concrete in Compression

DEFF Research Database (Denmark)

Dahl, Henrik; Brincker, Rune

is essential for understanding the fracture mechanism of concrete in compression. In this paper a series of tests is reported, carried out for the purpose of studying the fracture mechanical properties of concrete in compression. Including the measurement and study of the descending branch, a new experimental...... method has been used to investigate the influence of boundary conditions, loading rate, size effects and the influence of the strength on the fracture energy of high-strength concrete over the range 70 MPa to 150 MPa, expressed in nominal values....

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

Total Pancreatic Fracture Due to Blunt Trauma: Report of a Rare Case

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Kamil Gulpinar

2016-05-01

Full Text Available A rare case of pancreatic fracture due to blunt trauma was presented. The patient was 70 year old male who had a motor vehicle collision and was suspected a pancreatic trauma due his examinations with ultrasound and computerized tomography. The diagnosis of splenic injury and pancreas body total fracture in the point where the portal vein crosses the pancreatic body was made with the help of magnetic resonance cholangiopancreatography. He was taken to emergency surgery where a splenectomy and a distal pancreatectomy were performed. We represented this infrequent case of pancreatic fracture and its complications after blunt abdominal trauma and discuss the diagnostic and management practices.

Misdiagnosis of Talar Body or Neck Fractures as Ankle Sprains in Low Energy Traumas

Science.gov (United States)

Young, Ki-Won; Kim, Jin-Su; Cho, Hun-Ki; Choo, Ho-Sik; Park, Jang-Ho

2016-01-01

Background The talus has a very complex anatomical morphology and is mainly fractured by a major force caused by a fall or a traffic accident. Therefore, a talus fracture is not common. However, many recent reports have shown that minor injuries, such as sprains and slips during sports activities, can induce a talar fracture especially in the lateral or posterior process. Still, fractures to the main parts of the talus (neck and body) after ankle sprains have not been reported as occult fractures. Methods Of the total 102 cases from January 2005 to December 2012, 7 patients had confirmed cases of missed/delayed diagnosis of a talus body or neck fracture and were included in the study population. If available, medical records, X-rays, computed tomography scans, and magnetic resonance imaging of the confirmed cases were retrospectively reviewed and analyzed. Results In the 7-patient population, there were 3 talar neck fractures and 4 talar body fractures (coronal shearing type). The mechanisms of injuries were all low energy trauma episodes. The causes of the injuries included twisting of the ankle during climbing (n = 2), jumping to the ground from a 1-m high wall (n = 2), and twisting of the ankle during daily activities (n = 3). Conclusions A talar body fracture and a talar neck fracture should be considered in the differential diagnosis of patients with acute and chronic ankle pain after a minor ankle injury. PMID:27583114

Fracture patterns and the energy release rate of phosphorene.

Science.gov (United States)

Liu, Ning; Hong, Jiawang; Pidaparti, Ramana; Wang, Xianqiao

2016-03-14

Phosphorene, also known as monolayer black phosphorus, has been enjoying popularity in electronic devices due to its superior electrical properties. However, it's relatively low Young's modulus, low fracture strength and susceptibility to structural failure have limited its application in mechanical devices. Therefore, in order to design more mechanically reliable devices that utilize phosphorene, it is necessary to explore the fracture patterns and energy release rate of phosphorene. In this study, molecular dynamics simulations are performed to investigate phosphorene's fracture mechanism. The results indicate that fracture under uniaxial tension along the armchair direction is attributed to a break in the interlayer bond angles, while failure in the zigzag direction is triggered by the break in both intra-layer angles and bonds. Furthermore, we developed a modified Griffith criterion to analyze the energy release rate of phosphorene and its dependence on the strain rates and orientations of cracks. Simulation results indicate that phosphorene's energy release rate remains almost unchanged in the armchair direction while it fluctuates intensively in the zigzag direction. Additionally, the strain rate was found to play a negligible role in the energy release rate. The geometrical factor α in the Griffith's criterion is almost constant when the crack orientation is smaller than 45 degree, regardless of the crack orientation and loading direction. Overall, these findings provide helpful insights into the mechanical properties and failure behavior of phosphorene.

Supplemental Perioperative Oxygen to Reduce Surgical Site Infection after High Energy Fracture Surgery

Science.gov (United States)

2017-10-01

AWARD NUMBER: W81XWH-12-1-0588 TITLE: Supplemental Perioperative Oxygen to Reduce Surgical Site Infection after High- Energy Fracture Surgery...High- Energy Fracture Surgery 5a. CONTRACT NUMBER W81XWH-12-1-0588 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Robert V. O’Toole, MD...14 4 1. INTRODUCTION: The overall scope of this project is to address the treatment of high- energy military fractures, which has

Bearing Change to Metal-On-Polyethylene for Ceramic Bearing Fracture in Total Hip Arthroplasty; Does It Work?

Science.gov (United States)

Lee, Soong Joon; Kwak, Hong Suk; Yoo, Jeong Joon; Kim, Hee Joong

2016-01-01

We evaluated the short-term to midterm results of reoperation with bearing change to metal-on-polyethylene (MoP) after ceramic bearing fracture in ceramic-on-ceramic total hip arthroplasty. Nine third-generation ceramic bearing fractures (6 heads and 3 liners) were treated with bearing change to MoP. Mean age at reoperation was 52.7 years. Mean follow-up was 4.3 years. During follow-up, 2 of 3 liner-fractured hips and 1 of 6 head-fractured hips showed radiologic signs of metallosis and elevated serum chromium levels. Re-reoperation with bearing rechange to a ceramic head was performed for the hips with metallosis. One liner-fractured hip had periprosthetic joint infection. Dislocation occurred in 3 hips. From our experience, bearing change to MoP is not a recommended treatment option for ceramic bearing fracture in total hip arthroplasty. Copyright © 2016 Elsevier Inc. All rights reserved.

Thermodynamics of energy extraction from fractured hot dry rock

Energy Technology Data Exchange (ETDEWEB)

Lim, J S; Bejan, A [Duke Univ., Durham, NC (United States). Dept. of Mechanical Engineering and Materials Science; Kim, J H [Electric Power Research Inst., Palo Alto, CA (United States)

1992-03-01

It has been proposed to extract energy from the subterranean hot dry rock bed (HDR) by creating one or more narrow fractures in the rock and circulating cold water through the fractures. In time, the temperature of the rock region surrounding the crack drops under the influence of time-dependent conduction. This study presents the most basic thermodynamic aspects (first law and second law) of the HDR energy extraction process. It shows which parameters most influence the amount of useful energy (exergy) extracted from the HDR reservoir over a fixed time interval. For example, the water flow rate can be selected optimally in order to maximize the delivery of exergy over the lifetime of the HDR system. (author).

Obturator Artery Injury Resulting in Massive Hemorrhage From a Low-Energy Pubic Ramus Fracture.

Science.gov (United States)

Solarz, Mark K; Kistler, Justin M; Rehman, Saqib

2017-05-01

Pelvic ring fractures are common in the elderly population and are usually a result of low-energy trauma, such as falls from standing. In most cases, low-energy pelvic ring injuries can be treated with appropriate analgesia and early mobilization. Arterial injury resulting in hemodynamic instability from a low-energy pelvic ring injury is rare but, given the poor compliance of vessels in the elderly population, possible. These patients must be carefully monitored after the initial injury. The purpose of this report is to describe an elderly patient who sustained a superior pubic ramus fracture and arterial injury following a low-energy fall from standing that required angiographic intervention. Elderly patients who sustain low-energy or pelvic insufficiency fractures are unlike the younger population with high-energy pelvic fractures and hemodynamic collapse. Elderly patients can have a delayed presentation of arterial injury and require careful physical examination and close monitoring. Additionally, the authors provide a review of the literature for low-energy pelvic fractures. [Orthopedics. 2017; 40(3):e546-e548.]. Copyright 2017, SLACK Incorporated.

Periprosthetic fracture-dislocation in a loosened total knee replacement treated by knee arthrodesis

International Nuclear Information System (INIS)

Lozano Moreno, Francisco Jose

2004-01-01

We present a patient who was operated four years before performing a total knee replacement. She fell down resulting a periprosthetic femoral fracture and a prosthetic dislocation. After evaluating different treatments, we decided to do prosthetic removal and a knee arthrodesis using an intramedullar nail. The femoral fracture was fixed with wire cerclages. Knee arthrodesis is a procedure uses as a last option for the treatment of infected or loosed arthroplasties. In our case it was difficult to consider any other reconstructive procedure due to the association of fracture, dislocation and loosening. The evolution has been satisfactory with good functional result and without pain

Identifying Incomplete Atypical Femoral Fractures With Single-Energy Absorptiometry: Declining Prevalence

LENUS (Irish Health Repository)

McKenna, Malachi

2017-03-01

Atypical femur fractures (AFFs) are associated with long-term bisphosphonate (BP) therapy. Early identification of AFF prior to their completion provides an opportunity to intervene, potentially reducing morbidity associated with these fractures. Single-energy X-ray absorptiometry (SE) is an imaging method recently shown to detect incomplete AFF (iAFF) prior to fracture completion.

Reduced survival for uncemented compared to cemented total hip arthroplasty after operatively treated acetabular fractures.

Science.gov (United States)

Clarke-Jenssen, John; Westberg, Marianne; Røise, Olav; Storeggen, Stein Arne Øvre; Bere, Tone; Silberg, Ingunn; Madsen, Jan Erik

2017-11-01

Post traumatic arthritis and avascular necrosis of the femoral head are common complications after operatively treated acetabular fractures. This may cause severe disabilities for the patient, necessitating a total hip arthroplasty. Even though an arthroplasty may provide good symptomatic relief, the long-term results are more uncertain and no consensus exists according to preferred prosthetic designs. With this cohort study, we aimed to investigate the medium to long term arthroplasty survival and clinical results of total hip arthroplasty after operatively treated acetabular fractures. We included 52 patients treated with a secondary total hip arthroplasty at a median of 2.4 (0.1-14.1) years after an operatively treated acetabular fracture. The median age was 54 (11-82) years. Cemented arthroplasty was used for 33 patients, 10 patients had an uncemented arthroplasty and 9 patients received a hybrid arthroplasty. Average follow up was 8.0 (SD 5.0) years. Ten-year revision free arthroplasty survival was 79%. Uncemented arthroplasties had a significantly worse 10-year survival of 57%. Arthroplasties performed at a centre without a pelvic fracture service also had a significantly worse 10-years survival of 51%. Cox regression showed similar results with an 8-fold increase in risk of revision for both uncemented arthroplasties and operations performed at a non-pelvic trauma centre. Total hip arthroplasty secondary to an operatively treated acetabular fracture provides good symptomatic relief. These patients are, however, complex cases and are probably best treated at specialist centres with both pelvic trauma surgeons and arthroplasty surgeons proficient in complex revisions present. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fracture energy of stick-slip events in a large scale biaxial experiment

International Nuclear Information System (INIS)

Okubo, P.G.; Dieterich, J.H.

1981-01-01

The concept of apparent fracture energy for the shear failure process is employed by many authors in modeling earthquake sources as dynamically extending shear cracks. Using records of shear strain and relative displacement from stick-slip events generated along a simulated, prepared fault surface in a large (1.5m x 1.5m x 0.4m) granite block and a slip-weakening model for the fault, direct estimates of the apparent shear fracture energy of the stick-slip events have been obtained. For events generated on a finely ground fault surface, apparent fracture energy ranges from 0.06 J/m 2 at a normal stress of 1.1 MPa to 0.8 J/m 2 at a normal stress of 4.6 MPa. In contrast to estimates for tensile crack formation, we find that the apparent fracture energy of stick-slip events increases linearly with normal stress. The results for the slip-weakening model for the stick-slip events are generally consistent with constitutive fault models suggested by observations of stable sliding in smaller scale experiments

Differences in Classification Between Mono- and Polytrauma and Low- and High-Energy Trauma Patients With an Ankle Fracture: A Retrospective Cohort Study.

Science.gov (United States)

Briet, Jan Paul; Houwert, Roderick Marijn; Smeeing, Diederik P J; Dijkgraaf, Marcel G W; Verleisdonk, Egbert Jan; Leenen, Luke P H; Hietbrink, Falco

Although fracture type and treatment options for ankle fractures are well defined, the differences between mono- and polytrauma patients and low- and high-energy trauma have not been addressed. The aim of the present study was to compare the fracture type and trauma mechanism between mono- and polytrauma and low- and high-energy trauma patients with an ankle fracture. We performed a single-center retrospective cohort study. Fractures were classified according to the Lauge-Hansen classification and a descriptive classification. High-energy trauma (HET) was defined using triage criteria. All other patients were classified as having experienced low-energy trauma (LET). The patients were divided into 2 groups according to the injury severity score (ISS). Monotrauma patients were defined as patients with an ISS of 4 to 11 with an isolated ankle fracture or an ankle fracture with a minor contusion or laceration. Polytrauma patients were defined as patients with an ISS of ≥16 with ≥2 body regions involved. Patients with an ISS from 12 to 15 were excluded. A total of 96 patients were eligible for analysis. Of the 96 patients, 62 had experienced monotrauma and 34 had experienced polytrauma. A significant difference was found between the mono- and polytrauma patients in the Lauge-Hansen classification (p polytrauma patients. The same pattern was observed for ankle fractures after HET compared with LET (p polytrauma patients sustain different types of ankle fractures than patients with an isolated ankle fracture. This difference likely results from the high-energy transfer associated with polytrauma, because pronation abduction and supination adduction injuries were only observed after HET. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

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.

Low-energy fracture of posterolateral tibial plateau: treatment by a posterolateral prone approach.

Science.gov (United States)

Yu, Guang-Rong; Xia, Jiang; Zhou, Jia-Qian; Yang, Yun-Feng

2012-05-01

Most of the posterolateral tibial plateau fractures are caused by low-energy injury. The posterior fracture fragment could not be exposed and reduced well through traditional approaches. The aim of this study was to review the results of surgical treatment of this kind of fracture using posterolateral approach with patient in prone position. The low-energy posterolateral fracture is defined as the main part of articular depression or split fragment limited within the posterior half of the lateral column. Direct reduction and buttress plate fixation through the posterolateral prone approach was applied in all the patients. In our series, 15 of 132 (11.4%) patients with tibial plateau fractures were identified as low-energy posterolateral fractures. The clinical outcomes were available in 14 of the 15 patients through phone interviews and chart reviews. Mean follow-up was 35.1 months (range: 24-48 months). All the patients had anatomic or good reductions (≤ 2 mm step/gap). Average range of motion was 0.7 degrees to 123.2 degrees (5-110 degrees to 0-140 degrees). The complications were limited to one superficial wound infection, two slight flexion contractures, and five implants removal. The average modified hospital for special surgery knee score was 93.4 (range: 86-100). The posterolateral prone approach provides excellent visualization, which can facilitate the reduction and posterior buttress plate fixation for low-energy posterolateral tibial plateau fractures and shows encouraging results. V, therapeutic study.

Resolution of the threshold fracture energy paradox for solid particle erosion

Science.gov (United States)

Peck, Daniel; Volkov, Grigory; Mishuris, Gennady; Petrov, Yuri

2016-12-01

Previous models of a single erosion impact, for a rigid axisymmetric indenter defined by the shape function ?, have shown that a critical shape parameter ? exists which determines the behaviour of the threshold fracture energy. However, repeated investigations into this parameter have found no physical explanation for its value. Again utilising the notion of incubation time prior to fracture, this paper attempts to provide a physical explanation of this phenomena by introducing a supersonic stage into the model. The final scheme allows for the effect of waves along the indenters contact area to be taken into account. The effect of this physical characteristic of the impact on the threshold fracture energy and critical shape parameter ? are investigated and discussed.

Nontraumatic tibial polyethylene insert cone fracture in mobile-bearing posterior-stabilized total knee arthroplasty

OpenAIRE

Tanikake, Yohei; Hayashi, Koji; Ogawa, Munehiro; Inagaki, Yusuke; Kawate, Kenji; Tomita, Tetsuya; Tanaka, Yasuhito

2016-01-01

A 72-year-old male patient underwent mobile-bearing posterior-stabilized total knee arthroplasty for osteoarthritis. He experienced a nontraumatic polyethylene tibial insert cone fracture 27 months after surgery. Scanning electron microscopy of the fracture surface of the tibial insert cone suggested progress of ductile breaking from the posterior toward the anterior of the cone due to repeated longitudinal bending stress, leading to fatigue breaking at the anterior side of the cone, followed...

The equivalent energy method: an engineering approach to fracture

International Nuclear Information System (INIS)

Witt, F.J.

1981-01-01

The equivalent energy method for elastic-plastic fracture evaluations was developed around 1970 for determining realistic engineering estimates for the maximum load-displacement or stress-strain conditions for fracture of flawed structures. The basis principles were summarized but the supporting experimental data, most of which were obtained after the method was proposed, have never been collated. This paper restates the original bases more explicitly and presents the validating data in graphical form. Extensive references are given. The volumetric energy ratio, a modelling parameter encompassing both size and temperature, is the fundamental parameter of the equivalent energy method. It is demonstrated that, in an engineering sense, the volumetric energy ratio is a unique material characteristic for a steel, much like a material property except size must be taken into account. With this as a proposition, the basic formula of the equivalent energy method is derived. Sufficient information is presented so that investigators and analysts may judge the viability and applicability of the method to their areas of interest. (author)

[Preliminary analysis of total cost and life quality for elder patients with femoral neck fracture].

Science.gov (United States)

Liu, Haonan; He, Liang; Zhang, Guilin; Gong, Xiaofeng; Li, Ning

2015-09-01

To analyze the total cost and life quality of the femoral neck fracture patients who received different surgery and supplement comprehensive data of osteoporotic fracture. One hundred and five patients above 60-year old who were diagnosed femoral neck fracture and received operation in Department of Orthopedics ＆ Traumatology, Beijing Jishuitan Hospital were admitted into our study from August 2013 to December. According to the type of surgery there were 52 and 53 cases in internal fixation (IF) group and hemiarthroplasty (HA) group respectively. At first we collected the medical expense of the patients before and during hospitalization. And then the 1-year medical and non-medical expenses were collected by the cost diary ever 3 months after discharge. At the last follow-up we evaluated the life quality by the EuroQol-5 Dimensions (EQ-5D) and calculated the total cost. Outcome All the patients completed the operation successfully. No nonunion or delayed union cases in IF group, and no cases received revision surgery in both groups. The total average cost was 59 584.9 yuan including 79.1% medical cost and 20.9% non-medical cost. The primary treatment cost accounts for 84.1% of the medical cost. The cost for home care accounts for 90.7% of the non-medical care. The total and medical cost of IF group just account for 40.3% and 38.5% of the HA group and the non-medical showed no significant difference between the 2 groups (P>0.05). In addition the data of life quality and walking capability also showed no significant difference. The main cost for the femoral neck fracture is medical expense in 1-year follow-up. Both surgeries can provide satisfactory outcome, however IF may be more cost-effective compared to the HA because of the less total cost.

Multiple Low Energy Long Bone Fractures in the Setting of Rothmund-Thomson Syndrome

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Nicholas Beckmann

2015-01-01

Full Text Available Rothmund-Thomson syndrome is a rare autosomal recessive genodermatosis characterized by a poikilodermatous rash starting in infancy as well as various skeletal anomalies, juvenile cataracts, and predisposition to certain cancers. Although Rothmund-Thomson syndrome is associated with diminished bone mineral density in addition to multiple skeletal abnormalities, there are few reports of the association with stress fractures or pathologic fractures in low energy trauma or delayed healing of fractures. Presented is a case of a young adult male with Rothmund-Thomson syndrome presenting with multiple episodes of long bone fractures caused by low energy trauma with one of the fractures exhibiting significantly delayed healing. The patient was also found to have an asymptomatic stress fracture of the lower extremity, another finding of Rothmund-Thomson syndrome rarely reported in the literature. A thorough review of the literature and comprehensive presentation of Rothmund-Thomson syndrome is provided in conjunction with our case.

Total medical costs of treating femoral neck fracture patients with hemi- or total hip arthroplasty: a cost analysis of a multicenter prospective study

NARCIS (Netherlands)

P.T.P.W. Burgers (Paul); M. Hoogendoorn (Martine); E.A.C. Van Woensel; R.W. Poolman (Rudolf); M. Bhandari (Mohit); P. Patka (Peter); E.M.M. van Lieshout (Esther)

2016-01-01

textabstractSummary: The aim of this study was to determine the total medical costs for treating displaced femoral neck fractures with hemi- or total hip arthroplasty in fit elderly patients. The mean total costs per patient at 2 years of follow-up were €26,399. These results contribute to cost

A test specimen for characterizing the fracture energy of interfaces in composites

International Nuclear Information System (INIS)

Shaw, L.; Abbaschian, R.

1993-01-01

A sandwich-type chevron-notched specimen, which has a phase angle of loading near zero, is proposed to measure interfacial fracture energy arising mainly from chemical bonding. With the specimen configuration of this kind, the advantages from both sandwich test specimens and chevron-notched specimens can be combined to provide an easy and accurate test for the measurement of interfacial fracture energy. The validity of the specimen has been analyzed in terms of the mechanics of sandwich-type specimens and chevron-notched specimens, and demonstrated using the Al 2 O 3 /Nb bimaterial system. The results show that for a phase angle of loading around -7 degrees the Al 2 O 3 /Nb interface has a fracture energy of 9.3 ± 0.2 J/m 2 . 39 refs

Fractures of the greater trochanter following total hip replacement.

Science.gov (United States)

Brun, Ole-Christian L; Maansson, Lukas

2013-01-01

We studied the incidence of greater trochanteric fractures at our department following THR. In all we examined 911 patients retrospectively and found the occurance of a greater trochanteric fracture to be 3%. Patients with fractures had significantly poorer outcome on Oxford Hip score, Pain VAS, Satisfaction VAS and EQ-5D compared to THR without fractures. Greater trochanteric fracture following THR is one of the most common complications following THR. It has previously been thought to have little impact on the overall outcome following THR, but our study suggests otherwise.

Fluctuations of global energy release and crackling in nominally brittle heterogeneous fracture.

Science.gov (United States)

Barés, J; Hattali, M L; Dalmas, D; Bonamy, D

2014-12-31

The temporal evolution of mechanical energy and spatially averaged crack speed are both monitored in slowly fracturing artificial rocks. Both signals display an irregular burstlike dynamics, with power-law distributed fluctuations spanning a broad range of scales. Yet, the elastic power released at each time step is proportional to the global velocity all along the process, which enables defining a material-constant fracture energy. We characterize the intermittent dynamics by computing the burst statistics. This latter displays the scale-free features signature of crackling dynamics, in qualitative but not quantitative agreement with the depinning interface models derived for fracture problems. The possible sources of discrepancies are pointed out and discussed.

The effects of extracorporeal shockwave on acute high-energy long bone fractures of the lower extremity.

Science.gov (United States)

Wang, Ching-Jen; Liu, Hao-Chen; Fu, Te-Hu

2007-02-01

High-energy long bone fractures of the lower extremity are at risk of poor fracture healing and high rate of non-union. Extracorporeal shockwave was shown effective to heal non-union of long bone fracture. However, the effect of shockwave on acute fractures is unknown. The purpose of this study was to investigate the effects of shockwave on acute high-energy fractures of the lower extremity. Between January and October 2004, 56 patients with 59 acute high-energy fractures were enrolled in this study. Patients were randomly divided into two groups with 28 patients with 28 fractures in the study group and 28 patients with 31 fractures in the control group. Both groups showed similar age, gender, type of fracture and follow-up time. Patients in the study group received open reduction and internal fixation and shockwave treatment immediately after surgery on odd-numbered days of the week, whereas, patients in the control group received open reduction and internal fixation without shockwave treatment on even-numbered days of the week. Postoperative managements were similarly performed in both groups including crutch walking with non-weight bearing on the affected limb until fracture healing shown on radiographs. The evaluation parameters included clinical assessments of pain score and weight bearing status of the affected leg and serial radiographs at 3, 6 and 12 months. The primary end-point is the rate of non-union at 12 months, and the secondary end point is the rate of fracture healing at 3, 6 and 12 months. At 12 months, the rate of non-union was 11% for the study group versus 20% for the control group (P fracture healing was noted in the study group than the control group at 3, 6 and 12 months (P fracture healing and decreasing the rate of non-union in acute high-energy fractures of the lower extremity.

A study on the fracture energy of Steel Fiber Reinforced Concrete structures with initial cracks

International Nuclear Information System (INIS)

Chang, Dong-Il; Sim Jongsung; Chai, Won-Kyu; Lee, Myeong-Gu

1991-01-01

Fracture test is performed in order to investigate the fracture behavior of SFRC (Steel Fiber Reinforced Concrete) structures. Thirty six SFRC beams are used in this test. The relationships between loading, strain, and mid-span deflection of the beams are observed under the three point loading system. From the test results, the effects of the fiber content, the fiber aspect ratio and the initial crack ratio on the concrete fracture behavior were studied, and the flexural strength and the fracture energy of SFRC beams were also calculated. According to the regression technique, some empirical formulae for predicting the flexural strength and the fracture energy of SFRC beams are also suggested. (author)

Dislocation of total hip replacement in patients with fractures of the femoral neck

OpenAIRE

Enocson, Anders; Hedbeck, Carl-Johan; Tidermark, Jan; Pettersson, Hans; Ponzer, Sari; Lapidus, Lasse J

2009-01-01

Background Total hip replacement is increasingly used in active, relatively healthy elderly patients with fractures of the femoral neck. Dislocation of the prosthesis is a severe complication, and there is still controversy regarding the optimal surgical approach and its influence on stability. We analyzed factors influencing the stability of the total hip replacement, paying special attention to the surgical approach. Patients and methods We included 713 consecutive hips in a series of 698 p...

Low-energy extracorporeal shockwave therapy (ESWT improves metaphyseal fracture healing in an osteoporotic rat model.

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Gina A Mackert

Full Text Available As result of the current demographic changes, osteoporosis and osteoporotic fractures are becoming an increasing social and economic burden. In this experimental study, extracorporeal shock wave therapy (ESWT, was evaluated as a treatment option for the improvement of osteoporotic fracture healing.A well-established fracture model in the metaphyseal tibia in the osteoporotic rat was used. 132 animals were divided into 11 groups, with 12 animals each, consisting of one sham-operated group and 10 ovariectomized (osteoporotic groups, of which 9 received ESWT treatment. Different energy flux intensities (0.15 mJ/mm2, 0.35 mJ/mm2, or 0.55 mJ/mm2 as well as different numbers of ESWT applications (once, three times, or five times throughout the 35-day healing period were applied to the osteoporotic fractures. Fracture healing was investigated quantitatively and qualitatively using micro-CT imaging, quantitative real-time polymerase chain reaction (qRT-PCR analysis, histomorphometric analysis and biomechanical analysis.The results of this study show a qualitative and quantitative improvement in the osteoporotic fracture healing under low-energy (energy flux intensity: 0,15 mJ/mm2 ESWT and with fewer treatment applications per healing period.In conclusion, low-energy ESWT seems to exhibit a beneficial effect on the healing of osteoporotic fractures, leading to improved biomechanical properties, enhanced callus-quantity and -quality, and an increase in the expression of bone specific transcription factors. The results suggest that low-energy ESWT, as main treatment or as adjunctive treatment in addition to a surgical intervention, may prove to be an effective, simple to use, and cost-efficient option for the qualitative and quantitative improvement of osteoporotic fracture healing.

Ceramic-on-ceramic bearing fractures in total hip arthroplasty: an analysis of data from the National Joint Registry.

Science.gov (United States)

Howard, D P; Wall, P D H; Fernandez, M A; Parsons, H; Howard, P W

2017-08-01

Ceramic-on-ceramic (CoC) bearings in total hip arthroplasty (THA) are commonly used, but concerns exist regarding ceramic fracture. This study aims to report the risk of revision for fracture of modern CoC bearings and identify factors that might influence this risk, using data from the National Joint Registry (NJR) for England, Wales, Northern Ireland and the Isle of Man. We analysed data on 223 362 bearings from 111 681 primary CoC THAs and 182 linked revisions for bearing fracture recorded in the NJR. We used implant codes to identify ceramic bearing composition and generated Kaplan-Meier estimates for implant survivorship. Logistic regression analyses were performed for implant size and patient specific variables to determine any associated risks for revision. A total of 222 852 bearings (99.8%) were CeramTec Biolox products. Revisions for fracture were linked to seven of 79 442 (0.009%) Biolox Delta heads, 38 of 31 982 (0.119%) Biolox Forte heads, 101 of 80 170 (0.126%) Biolox Delta liners and 35 of 31 258 (0.112%) Biolox Forte liners. Regression analysis of implant size revealed smaller heads had significantly higher odds of fracture (chi-squared 68.0, p ceramic type. Liner thickness was not predictive of fracture (p = 0.67). Body mass index (BMI) was independently associated with revision for both head fractures (odds ratio (OR) 1.09 per unit increase, p = 0.031) and liner fractures (OR 1.06 per unit increase, p = 0.006). We report the largest independent study of CoC bearing fractures to date. The risk of revision for CoC bearing fracture is very low but previous studies have underestimated this risk. There is good evidence that the latest generation of ceramic has greatly reduced the odds of head fracture but not of liner fracture. Small head size and high patient BMI are associated with an increased risk of ceramic bearing fracture. Cite this article: Bone Joint J 2017;99-B:1012-19. ©2017 The British Editorial Society of Bone & Joint Surgery.

Comparison of fracture properties for two types of low alloy steels

International Nuclear Information System (INIS)

Nasreldin, A.M.

2004-01-01

The fracture properties of two types of low alloy steels used in the pressure vessel and boilers industry were determined. The first type was the steel A533-B which comprised a fully bainitic microstructure. The second one was the C-Mn steel which consisted of ferritic-pearlitic microstructure. The following fracture properties were determined using instrumented impact testing: the total fracture energy, the crack initiation and propagation energies, the brittleness transition temperature and the local fracture stress. The steel A533-B showed better fracture properties at high testing temperatures, while the C-Mn steel displayed higher resistance to brittle fracture at low testing temperatures. The results were discussed in relation to the difference in microstructure and fracture surface morphology for both steels

"Osteoporosis and orthopods" incidences of osteoporosis in distal radius fracture from low energy trauma.

LENUS (Irish Health Repository)

Bahari, Syah

2007-07-01

Fracture of the distal radius from low energy trauma is a common presentation to orthopaedic trauma services. This fragility type fracture is associated with underlying osteoporosis. Osteoporosis is a \\'silent disease\\' where fragility fracture is a common presentation. Orthopaedic surgeons may be the only physician that these patients encounter. We found a high percentage of female patients who sustained a fragility fracture of the distal radius have an underlying osteoporosis. Further management of osteoporosis is important to prevent future fragility fractures.

Risk factors for post-operative periprosthetic fractures following primary total hip arthroplasty with a proximally coated double-tapered cementless femoral component

DEFF Research Database (Denmark)

Gromov, K; Bersang, A; Nielsen, C S

2017-01-01

ratio were recorded post-operatively. Periprosthetic fractures were identified and classified according to the Vancouver classification. Regression analysis was performed to identify risk factors for early periprosthetic fracture. RESULTS: The mean follow-up was 713 days (1 to 2058). A total of 48......AIMS: The aim of this study was to identify patient- and surgery-related risk factors for sustaining an early periprosthetic fracture following primary total hip arthroplasty (THA) performed using a double-tapered cementless femoral component (Bi-Metric femoral stem; Biomet Inc., Warsaw, Indiana...... periprosthetic fractures (3.0%) were identified during the follow-up and median time until fracture was 16 days, (interquartile range 10 to 31.5). Patients with femoral Dorr type C had a 5.2 times increased risk of post-operative periprosthetic fracture compared with type B, while female patients had a near...

Depression after low-energy fracture in older women predicts future falls: a prospective observational study

Science.gov (United States)

2011-01-01

Background Falls are one of the main causes of fractures in elderly people and after a recent fracture, the risk of another fall is increased, resulting in subsequent fracture. Therefore, risk factors for future falls should be determined. We prospectively investigated the relationship between depression and the incidence of falls in post-menopausal women after a low-energy fracture. Methods At baseline, 181 women aged 60 years and older who presented with a recent low-energy fracture were evaluated at the fracture and osteoporosis outpatient clinics of two hospitals. As well as clinical evaluation and bone mineral density tests, the presence of depression (measured using the Edinburgh Depression Scale, EDS, depression cut-off > 11) and risk factors for falling were assessed. During two years of follow-up, the incidence of falls was registered annually by means of detailed questionnaires and interviews. Results Seventy-nine (44%) of the women sustained at least one fall during follow-up. Of these, 28% (n = 22) suffered from depression at baseline compared to 10% (n = 10) of the 102 women who did not sustain a fall during follow-up (Χ2 = 8.76, df = 1, p = .003). Multiple logistic regression showed that the presence of depression and co-morbidity at baseline were independently related to falls (OR = 4.13, 95% CI = 1.58-10.80; OR = 2.25, 95% CI = 1.11-4.56, respectively) during follow-up. Conclusions The presence of depression in women aged 60 years and older with recent low-energy fractures is an important risk factor for future falls. We propose that clinicians treating patients with recent low-energy fractures should anticipate not only on skeletal-related risk factors for fractures, but also on fall-related risk factors including depression. PMID:22060677

Depression after low-energy fracture in older women predicts future falls: a prospective observational study

Directory of Open Access Journals (Sweden)

van den Berg Martha

2011-11-01

Full Text Available Abstract Background Falls are one of the main causes of fractures in elderly people and after a recent fracture, the risk of another fall is increased, resulting in subsequent fracture. Therefore, risk factors for future falls should be determined. We prospectively investigated the relationship between depression and the incidence of falls in post-menopausal women after a low-energy fracture. Methods At baseline, 181 women aged 60 years and older who presented with a recent low-energy fracture were evaluated at the fracture and osteoporosis outpatient clinics of two hospitals. As well as clinical evaluation and bone mineral density tests, the presence of depression (measured using the Edinburgh Depression Scale, EDS, depression cut-off > 11 and risk factors for falling were assessed. During two years of follow-up, the incidence of falls was registered annually by means of detailed questionnaires and interviews. Results Seventy-nine (44% of the women sustained at least one fall during follow-up. Of these, 28% (n = 22 suffered from depression at baseline compared to 10% (n = 10 of the 102 women who did not sustain a fall during follow-up (Χ2 = 8.76, df = 1, p = .003. Multiple logistic regression showed that the presence of depression and co-morbidity at baseline were independently related to falls (OR = 4.13, 95% CI = 1.58-10.80; OR = 2.25, 95% CI = 1.11-4.56, respectively during follow-up. Conclusions The presence of depression in women aged 60 years and older with recent low-energy fractures is an important risk factor for future falls. We propose that clinicians treating patients with recent low-energy fractures should anticipate not only on skeletal-related risk factors for fractures, but also on fall-related risk factors including depression.

On the Processing of Spalling Experiments. Part II: Identification of Concrete Fracture Energy in Dynamic Tension

Science.gov (United States)

Lukić, Bratislav B.; Saletti, Dominique; Forquin, Pascal

2017-12-01

This paper presents a second part of the study aimed at investigating the fracture behavior of concrete under high strain rate tensile loading. The experimental method together with the identified stress-strain response of three tests conducted on ordinary concrete have been presented in the paper entitled Part I (Forquin and Lukić in Journal of Dynamic Behavior of Materials, 2017. https://doi.org/10.1007/s40870-017-0135-1). In the present paper, Part II, the investigation is extended towards directly determining the specific fracture energy of each observed fracture zone by visualizing the dynamic cracking process with a temporal resolution of 1 µs. Having access to temporal displacement fields of the sample surface, it is possible to identify the fracture opening displacement (FOD) and the fracture opening velocity of any principle (open) and secondary (closed) fracture at each measurement instance, that may or may not lead to complete physical failure of the sample. Finally, the local Stress-FOD curves were obtained for each observed fracture zone, opposed to previous works where indirect measurements were used. The obtained results indicated a much lower specific fracture energy compared to the results often found in the literature. Furthermore, numerical simulations were performed with a damage law to evaluate the validity of the proposed experimental data processing and compare it to the most often used one in the previous works. The results showed that the present method can reliably predict the specific fracture energy needed to open one macro-fracture and suggested that indirect measurement techniques can lead to an overestimate of specific fracture energy due to the stringent assumption of linear elasticity up-to the peak and the inability of having access to the real post-peak change of axial stress.

Fracture Energy Estimation of DCB Specimens Made of Glass/Epoxy: An Experimental Study

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V. Alfred Franklin

2013-01-01

Full Text Available This paper examines critical load and corresponding displacement of double cantilever beam (DCB composite specimens made of glass/epoxy of three different layups. Experiments were conducted on these laminates, and the fracture energy, GIc, was evaluated considering the root rotation at the crack tip. The present model requires the applied load-displacement history and crack extension to estimate fracture energy. Reduction schemes based on cubic and power law are also proposed to determine Young’s modulus and energy release rate and found good agreement with the published and test results.

Hip fractures. Epidemiology, risk factors, falls, energy absorption, hip protectors, and prevention

DEFF Research Database (Denmark)

Lauritzen, J B

1997-01-01

have a high risk of hip fracture (annual rate of 5-6%), and the incidence of falls is about 1,500 falls/1,000 persons/year. Most hip fractures are a result of a direct trauma against the hip. The incidence of falls on the hip among nursing home residents is about 290 falls/1,000 persons/year and about......%, corresponding to 9 out of 247 residents saved from sustaining a hip fracture. The review points to the essentials of the development of hip fracture, which constitutes; risk of fall, type of fall, type of impact, energy absorption, and lastly bone strength, which is the ultimate and last permissive factor......The present review summarizes the pathogenic mechanisms leading to hip fracture based on epidemiological, experimental, and controlled studies. The estimated lifetime risk of hip fracture is about 14% in postmenopausal women and 6% in men. The incidence of hip fractures increases exponentially...

Association of Insulin-like Growth Factor-1, Bone Mass and Inflammation to Low-energy Distal Radius Fractures and Fracture Healing in Elderly Women Attending Emergency Care.

Science.gov (United States)

Chisalita, Simona I; Chong, Lee Ti; Wajda, Maciej; Adolfsson, Lars; Woisetschläger, Mischa; Spångeus, Anna

2017-11-01

Elderly patients suffer fractures through low-energy mechanisms. The distal radius is the most frequent fracture localization. Insulin-like growth factor-1 (IGF1) plays an important role in the maintenance of bone mass and its levels decline with advancing age and in states of malnutrition. Our aim was to investigate the association of IGF1 levels, bone mass, nutritional status, and inflammation to low-energy distal radius fractures and also study if fracture healing is influenced by IGF1, nutritional status, and inflammation. Postmenopausal women, 55 years or older, with low-energy distal radius fractures occurring due to falling on slippery ground, indoors or outdoors, were recruited in the emergency department (ED) and followed 1 and 5 weeks after the initial trauma with biomarkers for nutritional status and inflammation. Fractures were diagnosed according to standard procedure by physical examination and X-ray. All patients were conservatively treated with plaster casts in the ED. Patients who needed interventions were excluded from our study. Fracture healing was evaluated from radiographs. Fracture healing assessment was made with a five-point scale where the radiological assessment included callus formation, fracture line, and stage of union. Blood samples were taken within 24 h after fracture and analyzed in the routine laboratory. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DXA). Thirty-eight Caucasian women, aged 70.5 ± 8.9 years (mean ± SD) old, were recruited. Nutritional status, as evaluated by albumin (40.3 ± 3.1 g/L), IGF1 (125.3 ± 39.9 μg/L), body mass index (26.9 ± 3.6 kg/m 2 ), arm diameter (28.9 ± 8.9 cm), and arm skinfold (2.5 ± 0.7 cm), was normal. A positive correlation was found between IGF1 at visit 1 and the lowest BMD for hip, spine, or radius (r = 0.39, P = 0.04). High sensitive C-reactive protein (hsCRP) and leukocytes were higher at the fracture event compared to 5 weeks later (P = 0.07 and P

Acetabular Fracture

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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

Electrophilic acid gas-reactive fluid, proppant, and process for enhanced fracturing and recovery of energy producing materials

Science.gov (United States)

Fernandez, Carlos A.; Heldebrant, David J.; Bonneville, Alain; Jung, Hun Bok; Carroll, Kenneth C.

2018-01-23

An electrophilic acid gas-reactive fracturing fluid, proppant, and process are detailed. The fluid expands in volume to provide rapid and controlled increases in pressure that enhances fracturing in subterranean bedrock for recovery of energy-producing materials. The proppant stabilizes fracture openings in the bedrock to enhance recovery of energy-producing materials.

Post-cracking Behaviour and Fracture Energy of Synthetic Fibre Reinforced Concrete

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Marta KOSIOR-KAZBERUK

2016-11-01

Full Text Available The paper reports the results of experimental programme focused on the effect of various synthetic fibres on fracture properties and ductility of concrete. The fracture energy was assessed on beams with initial notches in three-point bend test. The incorporation of synthetic fibres had a slight effect on mechanical properties of concrete but, at the same time, it had a significant influence on the fracture energy by modification of post-cracking behaviour of concrete. It was found that the modern synthetic fibres might be able to impart significant toughness and ductility to concrete. However, the beneficial effect of fibres depends on their length and flexibility. The analysis of load-deflection curves obtained made it possible to fit the simple function, describing the post-peak behaviour of fibre reinforced concrete, which can be useful for the calculation of GF value.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.13246

Is the early percutaneous spine total care to treat the polytrauma patient a good way?

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Gabriele Falzarano

2015-03-01

Full Text Available The “ideal“ timing and modality of fracture fixation for unstable thoracolumbar spine fractures in multiply injured patients remains controversial. The concept of “damage control orthopedics” is expressed. We presented a case report of a 27 years' old male who sustained a multilevel spine fractures associated a floating knee (Fraser's Type A, ulna fracture and carpal scaphoid fracture in July 2014 after car accident (very high energy trauma. All these fractures were treated in early total care. We reported a case control to discuss about the early spinal total care associated at orthopedic total care in patients with multiple trauma.

Fractal characteristics of fracture morphology of steels irradiated with high-energy ions

Energy Technology Data Exchange (ETDEWEB)

Xian, Yongqiang; Liu, Juan [Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000 (China); University of Chinese Academy of Science, Beijing 100049 (China); Zhang, Chonghong, E-mail: c.h.zhang@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000 (China); Chen, Jiachao [Paul Scherrer Institute, Villigen PSI (Switzerland); Yang, Yitao; Zhang, Liqing; Song, Yin [Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000 (China)

2015-06-15

Highlights: • Fractal dimensions of fracture surfaces of steels before and after irradiation were calculated. • Fractal dimension can effectively describe change of fracture surfaces induced by irradiation. • Correlation of change of fractal dimension with embrittlement of irradiated steels is discussed. - Abstract: A fractal analysis of fracture surfaces of steels (a ferritic/martensitic steel and an oxide-dispersion-strengthened ferritic steel) before and after the irradiation with high-energy ions is presented. Fracture surfaces were acquired from a tensile test and a small-ball punch test (SP). Digital images of the fracture surfaces obtained from scanning electron microscopy (SEM) were used to calculate the fractal dimension (FD) by using the pixel covering method. Boundary of binary image and fractal dimension were determined with a MATLAB program. The results indicate that fractal dimension can be an effective parameter to describe the characteristics of fracture surfaces before and after irradiation. The rougher the fracture surface, the larger the fractal dimension. Correlation of the change of fractal dimension with the embrittlement of the irradiated steels is discussed.

Bone images from dual-energy subtraction chest radiography in the detection of rib fractures.

Science.gov (United States)

Szucs-Farkas, Zsolt; Lautenschlager, Katrin; Flach, Patricia M; Ott, Daniel; Strautz, Tamara; Vock, Peter; Ruder, Thomas D

2011-08-01

To assess the sensitivity and image quality of chest radiography (CXR) with or without dual-energy subtracted (ES) bone images in the detection of rib fractures. In this retrospective study, 39 patients with 204 rib fractures and 24 subjects with no fractures were examined with a single exposure dual-energy subtraction digital radiography system. Three blinded readers first evaluated the non-subtracted posteroanterior and lateral chest radiographs alone, and 3 months later they evaluated the non-subtracted images together with the subtracted posteroanterior bone images. The locations of rib fractures were registered with confidence levels on a 3-grade scale. Image quality was rated on a 5-point scale. Marks by readers were compared with fracture localizations in CT as a standard of reference. The sensivity for fracture detection using both methods was very similar (34.3% with standard CXR and 33.5% with ES-CXR, p=0.92). At the patient level, both sensitivity (71.8%) and specificity (92.9%) with or without ES were identical. Diagnostic confidence was not significantly different (2.61 with CXR and 2.75 with ES-CXR, p=0.063). Image quality with ES was rated higher than that on standard CXR (4.08 vs. 3.74, prib fractures. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Incidence of low and high-energy fractures in persons with and without HIV infection: a Danish population-based cohort study.

Science.gov (United States)

Hansen, Ann-Brit E; Gerstoft, Jan; Kronborg, Gitte; Larsen, Carsten S; Pedersen, Court; Pedersen, Gitte; Obel, Niels

2012-01-28

To compare fracture risk in persons with and without HIV infection and to examine the influence of highly active antiretroviral therapy (HAART) initiation on risk of fracture. Population-based nationwide cohort study using Danish registries. Outcome measures were time to first fracture at any site, time to first low-energy and high-energy fracture in HIV-infected patients (n = 5306) compared with a general population control cohort (n = 26 530) matched by sex and age during the study period 1995-2009. Cox regression analyses were used to estimate incidence rate ratios (IRRs). HIV-infected patients had increased risk of fracture [IRR 1.5, 95% confidence interval (CI) 1.4-1.7] compared with population controls. The relative risk was lower in HIV-monoinfected patients (IRR 1.3, 95% CI 1.2-1.4) than in HIV/hepatitis C virus (HCV)-coinfected patients (IRR 2.9, 95% CI 2.5-3.4).Both HIV-monoinfected and HIV/HCV-coinfected patients had increased risk of low-energy fracture, IRR of 1.6 (95% CI 1.4-1.8) and 3.8 (95% CI 3.0-4.9). However, only HIV/HCV-coinfected patients had increased risk of high-energy fracture, IRR of 2.4 (95% CI 2.0-2.9). Among HIV-monoinfected patients the risk of low-energy fracture was only significantly increased after HAART exposure, IRR of 1.8 (95% CI 1.5-2.1). The increased risk in HAART-exposed patients was not associated with CD4 cell count, prior AIDS, tenofovir or efavirenz exposure, but with comorbidity and smoking. HIV-infected patients had increased risk of fracture compared with population controls. Among HIV-monoinfected patients the increased risk was observed for low-energy but not for high-energy fractures, and the increased risk of low-energy fracture was only observed in HAART-exposed patients.

Deformation and fracture of Cu alloy-stainless steel layered structures under dynamic loading

International Nuclear Information System (INIS)

McCoy, J.H.; Kumar, A.S.

1998-01-01

Fracture resistance of the current ITER first wall configuration, a copper alloy-stainless steel layered structure, is a major design issue. The question of dynamic crack propagation into and through the first wall structure is examined using dynamic finite element modeling (FEM). Several layered configurations that incorporate both strain and frictional energy dissipation during the fracture process are considered. With fixed overall specimen geometry, the energy required to extend a precrack is examined as a function of material properties, and the layer structure. It is found that the crack extension energies vary dramatically with the fracture strain of materials, and to a much lesser extent with the number of layers. In addition, it is found that crack propagation through the lower ductility copper alloy layer may be deflected at the stainless steel-copper interface and not result in total fracture of the structure. Although the total energy required is affected only to a small degree by the interface properties, the time to extend the precrack is strongly affected. By making proper selections of the interface and the layered material, crack propagation rates and the possibility of full fracture can be substantially reduced. (orig.)

Lower Lean Mass Measured by Dual-Energy X-ray Absorptiometry (DXA) is Not Associated with Increased Risk of Hip Fracture in Women: The Framingham Osteoporosis Study.

Science.gov (United States)

McLean, Robert R; Kiel, Douglas P; Berry, Sarah D; Broe, Kerry E; Zhang, Xiaochun; Cupples, L Adrienne; Hannan, Marian T

2018-01-05

Although muscle mass influences strength in older adults, it is unclear whether low lean mass measured by dual-energy X-ray absorptiometry (DXA) is an independent risk factor for hip fracture. Our objective was to determine the association between DXA lean mass and incident hip fracture risk among 1978 women aged 50 years and older participating in the Framingham Study Original and Offspring cohorts. Leg and total body lean mass (kg) were assessed from whole-body DXA scans collected in 1992-2001. Hip fracture follow-up extended from DXA assessment to the occurrence of fracture, death, drop-out, or end of follow-up in 2007. Cox proportional hazards regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) estimating the relative risk of hip fracture associated with a 1-kg increase in baseline lean mass. Mean age was 66 years (range 50-93). Over a median of 8 years of follow-up, 99 hip fractures occurred. In models adjusted for age, height, study cohort, and percent total body fat, neither leg (HR 1.11; 95% CI 0.94, 1.31) nor total body (HR 1.06; 95% CI 0.99, 1.13) lean mass were associated with hip fracture. After further adjustment for femoral neck bone mineral density, leg lean mass results were similar (HR 1.10; 95% CI 0.93, 1.30). In contrast, 1 kg greater total body lean mass was associated with 9% higher hip fracture risk (HR 1.09; 95% CI 1.02, 1.18). Our findings suggest that in women, lower lean mass measured by DXA is not associated with increased risk of hip fracture.

The total energy policy in Flanders

International Nuclear Information System (INIS)

Bouma, J.W.J.

1994-01-01

The policy of the Flemish region (Belgium) with regard to the total energy principle are presented. An overview of the main policy instruments to support energy saving and environmental-friendly investments as well as the development of new technologies is given. The total energy policy of the Flanders Region forms part of the general Flemish (energy) policy. (A.S.)

Total-factor energy efficiency in developing countries

International Nuclear Information System (INIS)

Zhang Xingping; Cheng Xiaomei; Yuan Jiahai; Gao Xiaojun

2011-01-01

This paper uses a total-factor framework to investigate energy efficiency in 23 developing countries during the period of 1980-2005. We explore the total-factor energy efficiency and change trends by applying data envelopment analysis (DEA) window, which is capable of measuring efficiency in cross-sectional and time-varying data. The empirical results indicate that Botswana, Mexico and Panama perform the best in terms of energy efficiency, whereas Kenya, Sri Lanka, Syria and the Philippines perform the worst during the entire research period. Seven countries show little change in energy efficiency over time. Eleven countries experienced continuous decreases in energy efficiency. Among five countries witnessing continuous increase in total-factor energy efficiency, China experienced the most rapid rise. Practice in China indicates that effective energy policies play a crucial role in improving energy efficiency. Tobit regression analysis indicates that a U-shaped relationship exists between total-factor energy efficiency and income per capita. - Research Highlights: → To measure the total-factor energy efficiency using DEA window analysis. → Focus on an application area of developing countries in the period of 1980-2005. → A U-shaped relationship was found between total-factor energy efficiency and income.

Total energy calculations from self-energy models

International Nuclear Information System (INIS)

Sanchez-Friera, P.

2001-06-01

Density-functional theory is a powerful method to calculate total energies of large systems of interacting electrons. The usefulness of this method, however, is limited by the fact that an approximation is required for the exchange-correlation energy. Currently used approximations (LDA and GGA) are not sufficiently accurate in many physical problems, as for instance the study of chemical reactions. It has been shown that exchange-correlation effects can be accurately described via the self-energy operator in the context of many-body perturbation theory. This is, however, a computationally very demanding approach. In this thesis a new scheme for calculating total energies is proposed, which combines elements from many-body perturbation theory and density-functional theory. The exchange-correlation energy functional is built from a simplified model of the self-energy, that nevertheless retains the main features of the exact operator. The model is built in such way that the computational effort is not significantly increased with respect to that required in a typical density-functional theory calculation. (author)

Total energy system in the future

International Nuclear Information System (INIS)

Hijikata, K.

1994-01-01

The possibility of improving the thermal efficiency of energy systems from an exergy point of view is discussed. In total energy systems, we should employ multi-pass recycling consisting of thermal and chemical energies. The recycling system is supported by electrical energy, which is provided by a renewable energy source or by excess commercial electric power. This total energy system should be considered not only in one country, but all around the globe. (author). 6 figs., 4 tabs., 8 refs

Treatment of neglected femoral neck fracture

Directory of Open Access Journals (Sweden)

Anil K Jain

2015-01-01

Full Text Available Intra-capsular femoral neck fractures are seen commonly in elderly people following a low energy trauma. Femoral neck fracture has a devastating effect on the blood supply of the femoral head, which is directly proportional to the severity of trauma and displacement of the fracture. Various authors have described a wide array of options for treatment of neglected/nonunion (NU femoral neck fracture. There is lack of consensus in general, regarding the best option. This Instructional course article is an analysis of available treatment options used for neglected femoral neck fracture in the literature and attempt to suggest treatment guides for neglected femoral neck fracture. We conducted the "Pubmed" search with the keywords "NU femoral neck fracture and/or neglected femoral neck fracture, muscle-pedicle bone graft in femoral neck fracture, fibular graft in femoral neck fracture and valgus osteotomy in femoral neck fracture." A total of 203 print articles were obtained as the search result. Thirty three articles were included in the analysis and were categorized into four subgroups based on treatment options. (a treated by muscle-pedicle bone grafting (MPBG, (b closed/open reduction internal fixation and fibular grafting (c open reduction and internal fixation with valgus osteotomy, (d miscellaneous procedures. The data was pooled from all groups for mean neglect, the type of study (prospective or retrospective, classification used, procedure performed, mean followup available, outcome, complications, and reoperation if any. The outcome of neglected femoral neck fracture depends on the duration of neglect, as the changes occurring in the fracture area and fracture fragments decides the need and type of biological stimulus required for fracture union. In stage I and stage II (Sandhu′s staging neglected femoral neck fracture osteosynthesis with open reduction and bone grafting with MPBG or Valgus Osteotomy achieves fracture union in almost 90

Hydraulic fracturing, energy transition and political engagement in the Netherlands

NARCIS (Netherlands)

Rasch, Elisabet Dueholm; Köhne, Michiel

2016-01-01

This paper analyses how citizens (re)define their relation to the state in the contestation of hydraulic fracturing in the Noordoostpolder (the Netherlands) in the context of energy transition. It approaches citizenship as the negotiations between governments and citizens about in-and exclusion

Bone images from dual-energy subtraction chest radiography in the detection of rib fractures

Energy Technology Data Exchange (ETDEWEB)

Szucs-Farkas, Zsolt, E-mail: zsolt.szuecs@insel.ch [Department of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland); Lautenschlager, Katrin, E-mail: katrin@students.unibe.ch [Department of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland); Flach, Patricia M., E-mail: patricia.flach@irm.unibe.ch [Institute of Forensic Medicine, University of Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland); Ott, Daniel, E-mail: daniel.ott@insel.ch [Department of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland); Strautz, Tamara, E-mail: tamara.strautz@insel.ch [Department of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland); Vock, Peter, E-mail: peter.vock@insel.ch [Department of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland); Ruder, Thomas D., E-mail: thomas.ruder@irm.unibe.ch [Institute of Forensic Medicine, University of Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland)

2011-08-15

Objective: To assess the sensitivity and image quality of chest radiography (CXR) with or without dual-energy subtracted (ES) bone images in the detection of rib fractures. Materials and methods: In this retrospective study, 39 patients with 204 rib fractures and 24 subjects with no fractures were examined with a single exposure dual-energy subtraction digital radiography system. Three blinded readers first evaluated the non-subtracted posteroanterior and lateral chest radiographs alone, and 3 months later they evaluated the non-subtracted images together with the subtracted posteroanterior bone images. The locations of rib fractures were registered with confidence levels on a 3-grade scale. Image quality was rated on a 5-point scale. Marks by readers were compared with fracture localizations in CT as a standard of reference. Results: The sensivity for fracture detection using both methods was very similar (34.3% with standard CXR and 33.5% with ES-CXR, p = 0.92). At the patient level, both sensitivity (71.8%) and specificity (92.9%) with or without ES were identical. Diagnostic confidence was not significantly different (2.61 with CXR and 2.75 with ES-CXR, p = 0.063). Image quality with ES was rated higher than that on standard CXR (4.08 vs. 3.74, p < 0.001). Conclusions: Despite a better image quality, adding ES bone images to standard radiographs of the chest does not provide better sensitivity or improved diagnostic confidence in the detection of rib fractures.

[Early total care pattern for intertrochanteric fracture of femur in the elderly].

Science.gov (United States)

Gu, Jie; Kang, Xin-yong; Xu, Hong-wei; Li, Yong-fu; Zahng, Bin; Guo, Jian; He, Zhen-nian

2016-06-01

To evaluate clinical results of early total care (ETC) treatment for elderly patients with intertrochanteric femur fractures. Clinical data of 106 elderly patients with intertrochanteric fracture treated from January 2012 and February 2015 were retrospectively studied. According to whether receiving the early total care mode, the patients were divided into 2 groups, 34 cases were diagnosed and treated with early total care pattern (ETC group), including 14 males and 20 females with an average age of (74.88 ± 4.38) years old ranging from 70 to 86. According to Evans types, 4 cases were type I, 5 cases were type II, 13 cases were type III, 11 cases were type IV, 1 case was type V. Seventy-two patients were treated with conventional trauma method (conventional group), including 35 males and 37 females with an average age of (74.46 ± 3.63) years old ranging from 70 to 85. According to Evans type, 8 cases were type I ,13 cases were type II, 25 cases were type III, 25 cases were type IV, and 1 case was type V. All fractures were treated with proximal femoral nails anti-rotation (PFNA). Operative time, hospital stays, leaving bed time, complications, cases of death at 1 year after operation, postoperative Harris score at 12 months were observed and compared. All patients were followed up, the time of ETC group ranged from 9 to 18 months with an average of 13.29 ± 1.51, and the time in conventional group ranged from 12 to 16 months with an average 12.93 ± 1.15, while there was no significant difference between two groups in time of following-up (t = 1.368, P = 0.174). There was no significant meaning in cases of death between ETC group (2 cases) and conventional group (8 cases). Three cases occurred complications in ETC group, and 20 cases in conventional group,there was obvious meaning between two groups (χ² = 0.739, P = 0.318). Operative time,hospital stays,leaving bed time in ETC group respectively was (2.03 ± 0.67) d, (15.41 ± 2.87) d and (3.62 ± 0.74) d

[Treatment of periprosthetic femoral fractures after total hip arthroplasty with specially constructed retrograde hollow nails].

Science.gov (United States)

Szalay, G; Meyer, C; Mika, J; Schnettler, R; Thormann, U

2014-12-01

Treatment of periprosthetic fractures by implantation of a specially constructed, retrograde hollow nail which fits over the tip of the prosthesis and becomes locked on it. Periprosthetic femoral fractures with firmly anchored prosthesis shaft after total hip arthroplasty of types B1 and C according to the Vancouver classification. Loosened prosthesis (type B2/B3) and trochanteric fractures (type A). Broken or damaged prosthesis, florid inflammation and soft tissue injuries in the operation field, contracted knee joint, advanced deformation in the knee joint and distal femur, enclosed prosthesis and general contraindications. In a supine position the periprosthetic fracture is exposed via a lateral access. For cemented prostheses the cement is removed around the tip of the prosthesis (at least 2-3 cm) and medullary cavity. Arthrotomy with flexion of the knee joint and marking of the nail entry point. Drill the medullary cavity, retrograde introduction of the nail, visually fit the nail over the tip of the prosthesis and lock the nail with the prosthesis. If necessary use additional spongiosaplasty or also placement of additional cerclages depending on fracture type and size of the defect zone. Lock the nail distally. Use intraoperative radiological imaging to control correct positioning and length of the nail. Close the wound layer by layer with placement of suction drainage devices and dressing. Partial loading for 6 weeks with a subsequent pain-adapted loading gradient until full loading is possible. If selective partial loading is not possible, a decision must be made in individual cases as to whether the intraoperative findings allow immediate full loading. From 2004 to 2011 a total of 25 periprosthetic femoral fractures in 25 patients were treated in 2 locations using specially constructed slotted hollow nails. Within the framework of a retrospective study 20 of these patients (16 female and 4 male; average age 77.2 [72-84] years) were clinically and

Ipsilateral stress fracture of the proximal fibula after total knee arthroplasty in a patient with severe valgus knee deformity on a background of Rheumatoid arthritis

Directory of Open Access Journals (Sweden)

Hirokazu Takai

Full Text Available Introduction: Previous studies have reported a lower extremity stress fracture after total knee arthroplasty (TKA. However, a fibular fracture after TKA is quite rare. We report a case of proximal fibula fracture after TKA in a patient with rheumatoid arthritis (RA. Presentation of case: A 45 year old woman with RA had severe knee and foot pain with an antalgic gait disturbance. There was a significant joint deformity in many of lower limb joints. Interval bilateral TKAs were performed two weeks apart. Right TKA was performed using a constraint-type prosthesis, through lateral parapatellar approach. Left TKA was performed using a posterior-stabilized (PS prosthesis through the more commonly employed, medial parapatellar approach. Seven weeks after the right TKA, the patient was found to have an atraumatic proximal fibular fracture. The fracture went on to heal conservatively. Discussion: The fracture was considered to have occurred after the TKA. The callus appeared eleven weeks after the TKA. The factors that contributed to the fracture were thought to be overload of the fragile bone secondarily to disuse osteopaenia, RA or potentially the significant valgus malalignment correction. The surgical approach, the implant or implantation or the persisting joint deformity, were thought to be contributing factors to the aetiology of the stress fracture. The resultant change in clinical outcome/course is outlined in this case report. Conclusion: A stress fracture of the proximal fibula has the potential in the aetiology of may cause other stress fractures, joint other instability, and/or malalignment of the total lower extremity. Keywords: Stress fracture, Insufficiency fracture, Total knee arthroplasty, Fibula fracture, Valgus deformity, Rheumatoid arthritis

Prevalence of silent vertebral fractures detected by vertebral fracture assessment in young Portuguese men with hyperthyroidism.

Science.gov (United States)

Barbosa, Ana Paula; Rui Mascarenhas, Mário; Silva, Carlos Francisco; Távora, Isabel; Bicho, Manuel; do Carmo, Isabel; de Oliveira, António Gouveia

2015-02-01

Hyperthyroidism is a risk factor for reduced bone mineral density (BMD) and osteoporotic fractures. Vertebral fracture assessment (VFA) by dual-energy X-ray absorptiometry (DXA) is a radiological method of visualization of the spine, which enables patient comfort and reduced radiation exposure. This study was carried out to evaluate BMD and the prevalence of silent vertebral fractures in young men with hyperthyroidism. We conducted a cross-sectional study in a group of Portuguese men aged up to 50 years and matched in hyperthyroidism (n=24) and control (n=24) groups. A group of 48 Portuguese men aged up to 50 years was divided and matched in hyperthyroidism (n=24) and control (n=24) groups. BMD (g/cm(2)) at L1-L4, hip, radius 33%, and whole body as well as the total body masses (kg) were studied by DXA. VFA was used to detect fractures and those were classified by Genant's semiquantitative method. No patient had previously been treated for hyperthyroidism, osteoporosis, or low bone mass. Adequate statistical tests were used. The mean age, height, and total fat mass were similar in both groups (P≥0.05). The total lean body mass and the mean BMD at lumbar spine, hip, and whole body were significantly decreased in the hyperthyroidism group. In this group, there was also a trend for an increased prevalence of reduced BMD/osteoporosis and osteoporotic vertebral fractures. The results obtained using VFA technology (confirmed by X-ray) suggest that the BMD changes in young men with nontreated hyperthyroidism may lead to the development of osteoporosis and vertebral fractures. This supports the pertinence of using VFA in the routine of osteoporosis assessment to detect silent fractures precociously and consider early treatment. © 2015 European Society of Endocrinology.

Analysis of impact energy to fracture un-notched charpy specimens made from railroad tank car steel

Science.gov (United States)

2007-09-11

This paper describes a nonlinear finite element analysis : (FEA) framework that examines the impact energy to fracture : unnotched Charpy specimens by an oversized, nonstandard : pendulum impactor called the Bulk Fracture Charpy Machine : (BFCM). The...

Fracture of the proximal tibia after revision total knee arthroplasty with an extensor mechanism allograft.

Science.gov (United States)

Klein, Gregg R; Levine, Harlan B; Sporer, Scott M; Hartzband, Mark A

2013-02-01

Extensor mechanism reconstruction with an extensor mechanism allograft (EMA) remains one of the most reliable methods for treating the extensor mechanism deficient total knee arthroplasty. We report 3 patients who were treated with an EMA who sustained a proximal tibial shaft fracture. In all 3 cases, a short tibial component was present that ended close to the level of the distal extent of the bone block. When performing an EMA, it is important to recognize that the tibial bone block creates a stress riser and revision to a long-stemmed tibial component should be strongly considered to bypass this point to minimize the risk of fracture. Copyright © 2013 Elsevier Inc. All rights reserved.

Humeral fractures due to low-energy trauma: an epidemiological survey in patients referred to a large emergency department in Northern Italy.

Science.gov (United States)

Pedrazzoni, M; Abbate, B; Verzicco, I; Pedrazzini, A; Benatti, M; Cervellin, G

2015-01-01

This survey describes the epidemiology of approximately 1800 low-energy humeral fractures seen in a large emergency department in Northern Italy over 7 years (2007-2013), highlighting the differences from previous Italian studies. The purpose of this study was to determine the incidence of humeral fractures due to low-energy trauma in patients 40 years of age or older referred to a large Emergency Department (Parma, Northern Italy) in a 7-year period (2007-2013). All humeral fractures referred to the emergency department of the Academic Hospital of Parma (the main hospital in the province with a catchment area of approximately 345,000) were retrieved from the hospital database using both ICD-9CM codes and text strings. The diagnosis of humeral fracture due to low-energy trauma was confirmed by medical records and X-ray reports, after exclusion of injuries due to a clear-cut high-energy trauma or cancer. The query identified 1843 humeral fractures (1809 first fractures), with a clear predominance in women (78 %). Fractures of the proximal humerus represented the large majority of humeral fractures (more than 85 %), with an incidence progressively increasing with age (more than 60-fold in women and 20-fold in men). Simultaneous fractures (hip in particular) were frequent especially after 85 years of age (1 out of 8 cases). When compared to other Italian studies, the incidence of humeral fractures was significantly lower than that derived from discharge data corrected for hospitalization rate (standardized rate ratio 0.74; p energy humeral fractures in Italy. Our results partly differ from previous Italian studies based on indirect estimations.

Effect of mix design on the size-independent fracture energy of normal- and high-strength self-compacting concrete

International Nuclear Information System (INIS)

Cifuentes, H.; Ríos, J.D.; Gómez, E.J.

2018-01-01

Self-compacting concrete has a characteristic microstructure inherent to its specific composition. The higher content of fine particles in self-compacting concrete relative to the equivalent vibrated concrete produces a different fracture behavior that affects the main fracture parameters. In this work, a comprehensive experimental investigation of the fracture behavior of self-compacting concrete has been carried out. Twelve different self-compacting concrete mixes with compressive strength ranging from 39 to 124 MPa (wider range than in other studies) have been subjected to three-point bending tests in order to determine the specific fracture energy. The influence of the mix design and its composition (coarse aggregate fraction, the water to binder ratio and the paste to solids ratio) on its fracture behavior has been analyzed. Moreover, further evidence of the objectivity of the size-independent fracture energy results, obtained by the two most commonly used methods, has been p [es

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.

PERIMENOPAUSAL WRIST FRACTURE - AN OPPORTUNITY FOR ...

African Journals Online (AJOL)

Review of Medscheme's administrative databases to study ... management of a wrist fracture between 1995 and 1998, and ... reviewed dual-energy ... from three general practices in the UK. ... and Torgerson6 estimated the total cost of treating osteoporotic .... us adults from fHANES Ill. / Bone Miner Res 1997; U, 1761-1768.

Heat Recovery from Multiple-Fracture Enhanced Geothermal Systems: The Effect of Thermoelastic Fracture Interactions

DEFF Research Database (Denmark)

Vik, Hedda Slatlem; Salimzadeh, Saeed; Nick, Hamid

2018-01-01

This study investigates the effect of thermoelastic interactions between multiple parallel fractures on energy production from a multiple-fracture enhanced geothermal system. A coupled thermo-hydro-mechanical finite element model has been developed that accounts for non-isothermal fluid flow within...... increased to maximise the net energy production from the system. Otherwise, the multiple-fracture system fails to improve the energy recovery from the geothermal reservoir, as initially intended....... aperture in the adjacent fracture, and facilitates the creation of favourable flow pathways between the injection and production wells. These flow paths reduce the energy production from the system. The effects of fracture spacing, reservoir temperature gradient and mechanical properties of the rock matrix...

Determination of the Fracture Energy of Concrete

DEFF Research Database (Denmark)

Hansen, Ernst Jan de Place; Stang, Henrik

1998-01-01

In a NORDTEST project two methods for determination of the fracture energy of concrete are compared; the Three-Point Bend Test (TPBT) and the Wedge Splitting Test (WST). The methods involve notched beams and notched, grooved cubes, respectively. The two methods are compared in relation to handling...... and precision (repeatability, reproducibility). Concrete with a water/cement ratio of 0.43 including fly ash as well as silica fume is investigated. The results show that WST is significantly faster to work with compared to TPBT, although the sawing procedure is more time consuming. Only when using laboratory...

Ankle fractures have features of an osteoporotic fracture.

Science.gov (United States)

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.

Effect of mix design on the size-independent fracture energy of normal- and high-strength self-compacting concrete

Directory of Open Access Journals (Sweden)

H. Cifuentes

2018-02-01

Full Text Available Self-compacting concrete has a characteristic microstructure inherent to its specific composition. The higher content of fine particles in self-compacting concrete relative to the equivalent vibrated concrete produces a different fracture behavior that affects the main fracture parameters. In this work, a comprehensive experimental investigation of the fracture behavior of self-compacting concrete has been carried out. Twelve different self-compacting concrete mixes with compressive strength ranging from 39 to 124 MPa (wider range than in other studies have been subjected to three-point bending tests in order to determine the specific fracture energy. The influence of the mix design and its composition (coarse aggregate fraction, the water to binder ratio and the paste to solids ratio on its fracture behavior has been analyzed. Moreover, further evidence of the objectivity of the size-independent fracture energy results, obtained by the two most commonly used methods, has been provided on the self-compacting concrete mixes.

Fault Lines: Seismicity and the Fracturing of Energy Narratives in Oklahoma

Science.gov (United States)

Grubert, E.; Drummond, V. A.; Brandt, A. R.

2016-12-01

Fault Lines: Seismicity and the Fracturing of Energy Narratives in Oklahoma Virginia Drummond1, Emily Grubert21Stanford University, Stanford Earth Summer Undergraduate Research Program2Stanford University, Emmett Interdisciplinary Program in Environment and ResourcesOklahoma is an oil state where residents have historically been supportive of the oil and gas industry. However, a dramatic increase in seismic activity between 2009 and 2015 widely attributed to wastewater injection associated with oil production is a new and highly salient consequence of oil development, affecting local communities' relationship to the environment and to the oil industry. Understanding how seismicity plays into Oklahoma's evolving dialogue about energy is integral to understanding both the current realities and the future of energy communities in Oklahoma.This research engages Oklahoma residents through open-ended interviews and mixed quantitative-qualitative survey research to characterize how energy narratives shape identity in response to conflict between environmental outcomes and economic interest. We perform approximately 20 interviews with residents of Oklahoma, with particular attention to recruiting residents from a wide range of age groups and who work either within or outside the oil and gas industry. General population surveys supplementing detailed interviews with information about community characteristics, social and environmental priorities, and experience with hazards are delivered to residents selected at random from zip codes known to have experienced significant seismicity. We identify narratives used by residents in response to tension between economic and environmental concerns, noting Oklahoma as an interesting case study for how a relatively pro-industry community reacts to and reframes its relationship with energy development, given conflict. In particular, seismicity has fractured the dominant narrative of oil development as positive into new narratives

Nontraumatic Fracture of the Femoral Condylar Prosthesis in a Total Knee Arthroplasty Leading to Mechanical Failure

Directory of Open Access Journals (Sweden)

Girish N. Swamy

2014-01-01

Full Text Available This paper reports a case of fatigue fracture of the femoral component in a cruciate-retaining cemented total knee arthroplasty (TKA. A 64-year-old man had undergone a primary TKA for osteoarthritis 10 years previously at another institution using the PFC-Sigma prosthesis. The patient recovered fully and was back to his regular activities. He presented with a history of sudden onset pain and locking of the left knee since the preceding three months. There was no history of trauma, and the patient was mobilizing with difficulty using crutches. Radiographs revealed fracture of the posterior condyle of the femoral prosthesis. Revision surgery was performed as an elective procedure revealing the broken prosthesis. The TC3RP-PFC revision prosthesis was used with a medial parapatellar approach. The patient recovered fully without any squeal. Mechanical failure of the knee arthroplasty prosthesis is rare, and nontraumatic fracture of the femoral metallic component has not been reported before.

Nontraumatic fracture of the femoral condylar prosthesis in a total knee arthroplasty leading to mechanical failure.

Science.gov (United States)

Swamy, Girish N; Quah, Conal; Bagouri, Elmunzar; Badhe, Nitin P

2014-01-01

This paper reports a case of fatigue fracture of the femoral component in a cruciate-retaining cemented total knee arthroplasty (TKA). A 64-year-old man had undergone a primary TKA for osteoarthritis 10 years previously at another institution using the PFC-Sigma prosthesis. The patient recovered fully and was back to his regular activities. He presented with a history of sudden onset pain and locking of the left knee since the preceding three months. There was no history of trauma, and the patient was mobilizing with difficulty using crutches. Radiographs revealed fracture of the posterior condyle of the femoral prosthesis. Revision surgery was performed as an elective procedure revealing the broken prosthesis. The TC3RP-PFC revision prosthesis was used with a medial parapatellar approach. The patient recovered fully without any squeal. Mechanical failure of the knee arthroplasty prosthesis is rare, and nontraumatic fracture of the femoral metallic component has not been reported before.

Fracture Energy of Plain Concrete Beams at Different Rates of Loading

DEFF Research Database (Denmark)

Ulfkjær, J. P.; Hansen, Lars Pilegaard; Madsen, S. H.

. The beams are tested in a closed loop servo controlled materials testing system. The experimental results for these preliminary tests show that the bending tensile strength is increasing with the displacement rate and that the fracture energy is constant at lower displacement rates and then increasing...

Fracture energy evolution of two concretes resistant to the action of freeze-thaw cycles

Directory of Open Access Journals (Sweden)

Enfedaque, A.

2014-03-01

Full Text Available The current standards that regulate use of structural concrete have highlighted the durability of concrete. However, how the fracture energy of concrete evolves under the action of freeze-thaw cycles is not well known. The fracture energy of two types of concrete, one with an air-entraining additive and the other with silica fume addition, is studied after four, 14 and 28 freeze-thaw cycles. The results obtained show that the concrete with an air-entraining additive was undamaged and that fracture energy grew slightly. In addition to this, they also showed that the concrete with silica fume addition suffered severe surface scaling and its fracture energy changed due to the greater fracture areas generated.La actual normativa que rige el empleo de hormigón estructural ha puesto enfásis en la durabilidad del hormigón. Sin embargo, no se conoce cómo evoluciona la energía de fractura del hormigón sometido a ciclos hielo- deshielo, lo cual es de vital importancia para asegurar la durabilidad y el correcto comportamiento mecánico de las estructuras de hormigón en entornos con heladas durante su vida útil. Se ha estudiado la evolución de la energía de fractura de un hormigón con aireante y de un hormigón con humo de sílice después de 4, 14 y 28 ciclos hielo-deshielo realizando ensayos de fractura. Los resultados muestran cómo el hormigón con aireante no sufre daño por los ciclos hielo-deshielo y cómo la energía de fractura del mismo aumenta ligeramente. El hormigón con humo de sílice se daña por los ciclos hielo-deshielo y reduce su energía de fractura al aumentar el area fracturada.

Dependence of the mechanical fracture energy of the polymeric composite material from the mixture of filler fractions

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E. M. Nurullaev

2015-01-01

Full Text Available This paper for the first time presents an equation for calculating the mechanical fracture energy of the polymeric composite material (PCM with regard to the basic formulation parameters. By means of the developed computer program the authors calculated the mechanical fracture energy of the polymer binder of the 3D cross-linked plasticized elastomer filled with multifractional silica. The solution of the integral equation was implemented using the corresponding dependence of stress on relative elongation at uniaxial tension. Engineering application of the theory was considered with respect to asphalt road covering. The authors proposed a generalized dependence of ruptural deformation of the polymer binder from the effective concentration of chemical and physical (intermolecular bonds for calculating the mechanical fracture energy of available and advanced PCMs as filled elastomers.

Secondary knee instability caused by fracture of the stabilizing insert in a dual-articular total knee

DEFF Research Database (Denmark)

Boesen, Morten P; Jensen, Tim Toftgaard; Husted, Henrik

2004-01-01

A case of a fractured polyethylene stabilizing insert causing secondary knee instability in a Dual-articular total knee arthroplasty (TKA) is presented. A 65-year-old woman who underwent surgery with a Dual-articular TKA 4 years earlier had a well-functioning prosthesis until a fall, after which......-articular knee....

Development of a brittle fracture acceptance criterion for the International Atomic Energy Agency (IAEA)

International Nuclear Information System (INIS)

Sorenson, K.B.; Salzbrenner, R.; Nickell, R.E.

1992-01-01

An effort has been undertaken to develop a brittle fracture acceptance criterion for structural components of nuclear material transportation casks. The need for such a criterion was twofold. First, new generation cask designs have proposed the use of ferritic steels and other materials to replace the austenitic stainless steel commonly used for structural components in transport casks. Unlike austenitic stainless steel which fails in a high-energy absorbing, ductile tearing mode, it is possible for these candidate materials to fail via brittle fracture when subjected to certain combinations of elevated loading rates and low temperatures. Second, there is no established brittle fracture criterion accepted by the regulatory community that covers a broad range of structural materials. Although the existing IAEA Safety Series number-sign 37 addressed brittle fracture, its the guidance was dated and pertained only to ferritic steels. Consultant's Services Meetings held under the auspices of the IAEA have resulted in a recommended brittle fracture criterion. The brittle fracture criterion is based on linear elastic fracture mechanics, and is the result of a consensus of experts from six participating IAEA-member countries. The brittle fracture criterion allows three approaches to determine the fracture toughness of the structural material. The three approaches present the opportunity to balance material testing requirements and the conservatism of the material's fracture toughness which must be used to demonstrate resistance to brittle fracture. This work has resulted in a revised Appendix IX to Safety Series number-sign 37 which will be released as an IAEA Technical Document within the coming year

Total-factor energy efficiency of regions in China

International Nuclear Information System (INIS)

Hu, J.-L.; Wang, S.-C.

2006-01-01

This paper analyzes energy efficiencies of 29 administrative regions in China for the period 1995-2002 with a newly introduced index. Most existing studies of regional productivity and efficiency neglect energy inputs. We use the data envelopment analysis (DEA) to find the target energy input of each region in China at each particular year. The index of total-factor energy efficiency (TFEE) then divides the target energy input by the actual energy input. In our DEA model, labor, capital stock, energy consumption, and total sown area of farm crops used as a proxy of biomass energy are the four inputs and real GDP is the single output. The conventional energy productivity ratio regarded as a partial-factor energy efficiency index is computed for comparison in contrast to TFEE; our index is found fitting better to the real case. According to the TFEE index rankings, the central area of China has the worst energy efficiency and its total adjustmentof energy consumption amount is over half of China's total. Regional TFEE in China generally improved during the research period except for the western area. A U-shape relation between the area's TFEE and per capita income in the areas of China is found, confirming the scenario that energy efficiency eventually improves with economic growth

Periprosthetic femoral fracture within two years after total hip replacement:

DEFF Research Database (Denmark)

Thien, T. M.; Chatziagorou, G.; Garellick, G.

2014-01-01

BACKGROUND: We used the Nordic Arthroplasty Register Association database to evaluate whether age, sex, preoperative diagnosis, fixation, and implant design influence the risk of revision arthroplasty due to periprosthetic fracture within two years from operation of a primary total hip replacement....... METHODS: Included in the study were 325,730 cemented femoral stems and 111,899 uncemented femoral stems inserted from 1995 to 2009. Seven frequently used stems (two cemented stems [Exeter and Lubinus SP II] and five uncemented stems [Bi-Metric, Corail, CLS Spotorno, ABG I, and ABG II]) were specifically...... studied. RESULTS: The incidence of revision at two years was low: 0.47% for uncemented stems and 0.07% for cemented stems. Uncemented stems were much more likely to have this complication (relative risk, 8.72 [95% confidence interval, 7.37 to 10.32]; p

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...

Second hip fractures at Chiang Mai University Hospital.

Science.gov (United States)

Wongtriratanachai, Prasit; Chiewchantanakit, Siripong; Vaseenon, Tanawat; Rojanasthien, Sattaya; Leerapun, Taninnit

2015-02-01

Hip fractures are a major public health problem. Patients who have suffered a hip fracture have an increased risk of a subsequent hip fracture. This study examines the incidence ofsecondhip fractures and attempts to identify underlying risk factors. To examine the incidence ofsecond hip fractures in osteoporotic patients at Chiang Mai University Hospital and to identify risk factors related to second hip fractures. A retrospective review was conducted of all low-energy mechanism hip fracture patients admitted during 2008 and 2009. Analysis of second hip fractures was conducted using survival analysis and logistic regression analysis. A total of 191 patients were observed for 391.68 person-years (mean 2.05 person-years per patient). Among that group, nine second hip fractures were identified, an overall incidence rate of 0.023 second fractures per person-year. Second hip fractures tended to occur within the first year following an initial hip fracture. There were no significant differences related to either gender or comorbid medical conditions. Logistic regression analysis revealed that increased risk of a second hip fracture was associated with age (highest between 80 to 89 years) and patients who were not treated for osteoporosis following their initial fracture. The incidence of second hip fractures at Chiang Mai University Hospital was 0.023 per person-year Careful follow-up of older patients, especially those over 80, and treatment ofosteoporosis with bisphosphonate plus vitamin D and calcium supplements was correlated with a reduction in the incidence of second hip fractures.

Fracture Behavior and Properties of Functionally Graded Fiber-Reinforced Concrete

International Nuclear Information System (INIS)

Roesler, Jeffery; Bordelon, Amanda; Gaedicke, Cristian; Park, Kyoungsoo; Paulino, Glaucio

2008-01-01

In concrete pavements, a single concrete mixture design is selected to resist mechanical loading without attempting to adversely affect the concrete pavement shrinkage, ride quality, or noise attenuation. An alternative approach is to design distinct layers within the concrete pavement surface which have specific functions thus achieving higher performance at a lower cost. The objective of this research was to address the structural benefits of functionally graded concrete materials (FGCM) for rigid pavements by testing and modeling the fracture behavior of different combinations of layered plain and synthetic fiber-reinforced concrete materials. Fracture parameters and the post-peak softening behavior were obtained for each FGCM beam configuration by the three point bending beam test. The peak loads and initial fracture energy between the plain, fiber-reinforced, and FGCM signified similar crack initiation. The total fracture energy indicated improvements in fracture behavior of FGCM relative to full-depth plain concrete. The fracture behavior of FGCM depended on the position of the fiber-reinforced layer relative to the starter notch. The fracture parameters of both fiber-reinforced and plain concrete were embedded into a finite element-based cohesive zone model. The model successfully captured the experimental behavior of the FGCMs and predicted the fracture behavior of proposed FGCM configurations and structures. This integrated approach (testing and modeling) demonstrates the viability of FGCM for designing layered concrete pavements system

Impact of specific fracture energy investigated in front of the crack tip of three-point bending specimen

Czech Academy of Sciences Publication Activity Database

Klon, J.; Sobek, J.; Malíková, L.; Seitl, Stanislav

2017-01-01

Roč. 11, č. 41 (2017), s. 183-190 ISSN 1971-8993 Institutional support: RVO:68081723 Keywords : Finite element method * Loading curve * Specific fracture energy * Three-point bending test * Work of fracture Subject RIV: JL - Materials Fatigue, Friction Mechanics OBOR OECD: Audio engineering, reliability analysis

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.

Pre-hospital dietary intake correlates with muscle mass at the time of fracture in older hip fractured patients

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Riccardo eCalvani

2014-11-01

Full Text Available Background. Failure to meet an adequate dietary intake is involved in the pathogenesis of sarcopenia and osteoporosis, which in turn increase the risk for falls and fractures, respectively. Older people with hip fracture are often protein-malnourished at hospitalization. Whether low protein-energy intake is associated with muscle atrophy in hip fractured patients is presently unknown. This information is necessary for the development of novel strategies to manage this especially vulnerable patient population. The aim of this study was therefore to explore the relationship between dietary intake and muscle mass in older hip fractured patients.Methods. Analyses were conducted in hip fractured elderly admitted to an orthopedic and trauma surgery ward (University Hospital. Muscle mass was estimated by bioelectrical impedance analysis within 24 h from admission. Dietary information was collected via 24-h dietary recall and nutrient intakes calculated by a nutrition software.Results. Among 62 hip fractured patients (mean age 84.6±7.6 years, 84% women, the average energy intake was 929.2±170.3 Kcal/day, with higher values reported by men (1.046.8±231.4 Kcal/day relative to women (906.5±148.3 Kcal/day; p=0.01. Absolute and normalized protein intake was 50.0±13.5 g/day and 0.88±0.27 g/kg (body weight/day, respectively, with no gender differences. A positive correlation was determined between total energy intake and muscle mass (r=0.384; p=0.003. Similarly, protein and leucine consumption was positively correlated with muscle mass (r=0.367 and 0.311, respectively; p=0.005 for both.Conclusions. A low intake of calories, protein and leucine is associated with reduced muscle mass in hip fractured elderly. Given the relevance of sarcopenia as a risk factor for adverse outcomes in this patient population, our findings highlight the importance of a comprehensive dietary assessment for the detection of nutritional deficits predisposing to or aggravating

Clinical Outcomes and 90-Day Costs Following Hemiarthroplasty or Total Hip Arthroplasty for Hip Fracture.

Science.gov (United States)

Nichols, Christine I; Vose, Joshua G; Nunley, Ryan M

2017-09-01

In the era of bundled payments, many hospitals are responsible for costs from admission through 90 days postdischarge. Although bundled episodes for hip fracture will have a separate target price for the bundle, little is known about the 90-day resource use burden for this patient population. Using Medicare 100% Standard Analytic Files (2010-2014), we identified patients undergoing hemiarthroplasty or total hip arthroplasty (THA). Patients were aged 65 and older with admitting diagnosis of closed hip fracture, no concurrent fractures of the lower limb, and no history of hip surgery in the prior 12 months baseline. Continuous Medicare-only enrollment was required. Complications, resource use, and mortality from admission through 90 days following discharge (follow-up) were summarized. Four cohorts met selection criteria for analysis: (1) hemiarthroplasty diagnosis-related group (DRG) 469 (N = 19,634), (2) hemiarthroplasty DRG 470 (N = 77,744), (3) THA DRG 469 (N = 1686), and (4) THA DRG 470 (N = 9314). All-cause mortality during the study period was 51.6%, 29.5%, 48.1%, and 24.9% with mean 90-day costs of $28,952, $19,243, $29,763, and $18,561, respectively. Most of the patients waited 1 day from admission to surgery (41%-51%). Incidence of an all-cause complication was approximately 70% in each DRG 469 cohort and 14%-16% in each DRG 470 cohort. This study confirms patients with hip fracture are a costly subpopulation. Tailored care pathways to minimize post-acute care resource use are warranted for these patients. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Patients with rett syndrome sustain low-energy fractures

DEFF Research Database (Denmark)

Roende, Gitte; Ravn, Kirstine; Fuglsang, Kathrine

2011-01-01

We present the first case-control study addressing both fracture occurrence and fracture mechanisms in Rett syndrome (RTT). Two previous studies have shown increased fracture risk in RTT. This was also our hypothesis regarding the Danish RTT population. Therefore, we investigated risk factors...

Analysis of the intergranular fracture surface by the Fourier spectrum method

Energy Technology Data Exchange (ETDEWEB)

Hao Yao; Tian Jifeng; Wang Zhongguang (National Lab. for Fatigue and Fracture of Materials, Inst. of Metal Research, Academia Sinica, Shen Yang (China))

1991-11-30

A quantitative analysis of the fracture surface of a 1045 steel was undertaken in order to relate important microstructural features to brittle intergranular fractures in the steel. It was found that the character of the profile was not random but periodic. There is a direct correspondence between the Fourier spectrum of the profile and the microstructure features. Utilization of secondary-electron line scanning facilitated the analysis of the fracture surface in this case. The results of the analysis from both the profile and the scanning line showed that the first autocorrelation length is related to the average grain size and that the total power corresponds to the impact energy of the fracture. (orig.).

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

Point-of-Care Phalangeal Bone Mineral Density Measurement Can Reduce the Need of Dual-Energy X-Ray Absorptiometry Scanning in Danish Women at Risk of Fracture

DEFF Research Database (Denmark)

Holmberg, Teresa; Bech, Mickael; Gram, Jeppe

2016-01-01

Identifying persons with a high risk of osteoporotic fractures remains a challenge. DXA uptake in women with elevated risk of osteoporosis seems to be depending on distance to scanning facilities. This study aimed to investigate the ability of a small portable scanner in identifying women...... with reduced bone mineral density (BMD), and to define triage thresholds for pre-selection. Total hip and lumbar spine BMD was measured by dual-energy X-ray absorptiometry and phalangeal BMD by radiographic absorptiometry in 121 Danish women with intermediate or high 10-year fracture probability (aged 61...... and only 6 % of women in the low-risk group would be false negatives....

Surgical Site Infection Following Fixation of Acetabular Fractures.

Science.gov (United States)

Iqbal, Faizan; Younus, Sajid; Asmatullah; Zia, Osama Bin; Khan, Naveed

2017-09-01

Acetabular fractures are mainly caused by high energy trauma. Surgical fixation of these fractures requires extensive surgical exposure which increases the length of operation and blood loss as well. This may increase the risk of surgical site infection. Our aim is to evaluate the prevalence of surgical site infections and the risk factors associated with it so as to minimize its chances. A total of 261 patients who underwent acetabular fracture surgery were retrospectively reviewed. Patients were divided into 2 groups, with or without surgical site infection. Factors examined include patients' gender, age, body mass index (BMI), time between injury and surgery, operative time, estimated blood loss, number of packed red blood cell transfused, length of total intensive care unit (ICU) stay, fracture type, surgical approach, smoking status, patients' comorbids and associated injuries. Fourteen patients (5.4%) developed surgical site infection. Out of 14 infections, 4 were superficial and 10 were deep. The factors that were found to be associated with surgical site infection following acetabular fracture fixation were prolonged operation time, increased BMI, prolonged ICU stay, larger amount of packed red blood cell transfused and associated genitourinary and abdominal trauma. In our study, we conclude that measures should be undertaken to attenuate the chances of surgical site infection in this major surgery by considering the risk factors significantly associated with it.

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

Science.gov (United States)

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.

Incidence of low- and high-energy fractures in persons with and without HIV-infection: a Danish population-based cohort study

DEFF Research Database (Denmark)

Hansen, Ann-Brit E; Gerstoft, Jan; Kronborg, Gitte

2012-01-01

significantly increased after HAART-exposure, IRR of 1.8 (95% CI; 1.5-2.1). The increased risk in HAART-exposed patients was not associated with CD4 cell count, prior AIDS, tenofovir or efavirenz exposure, but with comorbidity and smoking. CONCLUSIONS:: HIV-infected patients had increased risk of fracture......OBJECTIVE:: To compare fracture risk in persons with and without HIV-infection and to examine the influence of HAART initiation on risk of fracture. DESIGN:: Population-based nationwide cohort study using Danish registries. METHODS:: Outcome measures were time to first fracture at any site, time...... to first low-energy and high-energy fracture in HIV-infected patients (n¿=¿5,306) compared with a general population control cohort (n¿=¿26,530) matched by sex and age during the study period 1995 to 2009. Cox regression analyses were used to estimate incidence rate ratios (IRR). RESULTS:: HIV-infected...

Comparison of femoral neck fracture healing and affected limb pain after anterolateral-approach minimally invasive total hip replacement and hemiarthroplasty

Directory of Open Access Journals (Sweden)

Xiao-Dong Cao

2017-04-01

Full Text Available Objective: To study the differences in femoral neck fracture healing and affected limb pain after anterolateral-approach minimally invasive total hip replacement and hemiarthroplasty. Methods: A total of 92 patients with femoral neck fracture who received hip replacement in our hospital between May 2013 and December 2015 were selected and randomly divided into total hip and half hip group, total hip group received anterolateral-approach minimally invasive total hip replacement, half hip group received anterolateral-approach minimally invasive hemiarthroplasty, and 1 month after operation, serum was collected to detect the levels of bone metabolism markers, osteocyte cytokines, SP and CGRP. Results: 1 month after operation, serum PINP, PICP, BMP, TGF-β, FGF, IGF-I and IGF-II levels of total hip group were significantly higher than those of half hip group while TRAP5b and CatK levels were significantly lower than those of half hip group; the day after operation, serum pain media SP and CGRP levels were not significantly different between the two groups of patients; 36 h after operation, serum SP and CGRP levels of total hip group were significantly lower than those of half hip group. Conclusion: The bone metabolism after anterolateral-approach minimally invasive total hip replacement is better than that after hemiarthroplasty, and the degree of pain is less than that after hemiarthroplasty.

Scaphoid fracture: Bone marrow edema detected with dual-energy CT virtual non-calcium images and confirmed with MRI

Energy Technology Data Exchange (ETDEWEB)

Dareez, Nazeer M.; Engesland, Eirin; Lindland, Elisabeth S. [Department of Radiology, SSHF Arendal, Arendal (Norway); Dahlslett, Kristine H. [Haukelands Universitetssjukehus, Department of Radiology, Bergen (Norway)

2017-12-15

We aimed to determine whether bone marrow edema (BME) in acute traumatic scaphoid fracture could be demonstrated with dual-energy CT (DECT) using MRI as the gold standard. In recent years, virtual non-calcium (VNCa) images have been used to demonstrate BME in trauma cases, for example, in vertebral compression fractures, hip trauma to detect occult fractures and knee fractures. We present three cases of acute scaphoid trauma. Two patients had subtle or invisible fractures on x-ray and conventional CT images, while DECT VNCa images clearly visualized the BME, which was confirmed by MRI. One patient had negative findings on both VNCa and MRI images. The DECT VNCa algorithm is a promising technique to demonstrate BME in scaphoid fractures, with potential for increasing the diagnostic value of CT in this type of injury. (orig.)

Hybrid external fixation in high-energy elbow fractures: a modular system with a promising future.

Science.gov (United States)

Lerner, A; Stahl, S; Stein, H

2000-12-01

Severe, high-energy, periarticular elbow injuries producing a "floating joint" are a major surgical challenge. Their reconstruction and rehabilitation are not well documented. Therefore, the following reports our experience with treating such injuries caused by war wounds. Seven adults with compound open peri- and intra-articular elbow fractures were treated in hybrid ring tubular fixation frames. After debridement, bone stabilization, and neurovascular reconstructions, early controlled daily movements were started in the affected joint. These seven patients had together seven humeral, five radial, and six ulnar fractures. All fractures united at a median time of 180 days. No deep infection developed. The functional end results assessed by the Khalfayan functional score were excellent in two, good in one, and fair in four of these severely mangled upper extremities. None was amputated. The Mangled Extremity Severity Score has been shown to be unable to provide a reliable assessment for severe high-energy limb injuries surgically managed with the modular hybrid thin wire tubular external fixation system. This hybrid system is a very useful addition to the surgical armamentarium of orthopedic trauma surgeons. It both allows complex surgical reconstructions and reduces the incidence of deep infections in these heavily contaminated injuries. The hybrid circular (thin wire) external fixation system is very modular and may provide secure skeletal stabilization even in cases of severely comminuted juxta-articular fractures on both sides of the elbow joint (floating elbow) with severe damage to soft tissues. This fixation system allows individual fixation of forearm bone fractures, thus allowing the preservation of pronation-supination movements.

Determining fracture energy parameters of concrete from the modified compact tension test

Directory of Open Access Journals (Sweden)

A. Fernández-Canteli

2014-10-01

Full Text Available The modified compact tension (MCT test, though not yet recognized as a valid test for determining fracture energy of concrete, is believed to represent a plausible and suitable alternative versus other well established procedures, such as the wedge-splitting test (WST and the three point (3PB or four point bending (4PB tests, due to its simplicity and low cost. The aim of the paper is twofold: Firstly, to demonstrate the necessary correspondence between the experimental MCT test setup and finite element simulations and secondly, to initiate the way of establishing the desirable conversion between the fracture energy parameter values resulting from the MCT test and the standard conventional procedures. MCT tests are carried out and compared with the numerical results from 2-D and 3-D finite element calculations using the commercial codes ABAQUS and ATENA, the latter being specifically developed for applications on concrete structures and elements. In this way, the usability of the modified compact tension test for practical purposes is confirmed.

Clinical Utility of Dual-Energy CT Analysis of Bone Marrow Edema in Acute Wrist Fractures.

Science.gov (United States)

Ali, Ismail T; Wong, William D; Liang, Teresa; Khosa, Faisal; Mian, Memoona; Jalal, Sabeena; Nicolaou, Savvas

2018-04-01

The purpose of this study is to determine the utility of dual-energy CT (DECT) for assessing carpal fractures and to obtain an attenuation value cutoff (in Hounsfield units) to identify bone marrow edema due to an acute carpal fracture. In this retrospective study, 24 patients who presented with wrist fractures from September 3, 2014, through March 9, 2015, underwent imaging with DECT (80 and 140 kVp). Using the three-material decomposition algorithm specific for virtual noncalcium to construct images, two radiologists identified carpal fractures and associated bone marrow edema. Readers noted the attenuation at areas with and without bone marrow edema. The cutoff value was obtained by ROC analysis and was internally validated on 13 separate patients with suspected wrist fractures. A p edema than in areas without it (p edema associated with acute wrist fractures with 100% sensitivity and 99.5% specificity, compared with visual DECT interpretation. In the 13 validation cases, the cutoff of 5.90 HU identified bone marrow edema with 100% accuracy, compared with visual interpretation. Kappa values were 0.83 between the two readings by reader 1, and 0.73 and 0.96 comparing the two readings of reader 1 with the reading by reader 2. DECT is a useful tool for identifying bone marrow edema in the setting of acute wrist fractures, providing an alternative to MRI. A cutoff value of 5.90 HU can be used for accurate diagnosis and exclusion of carpal fractures.

Isolated Transverse Sacrum Fracture: A Case Report

Directory of Open Access Journals (Sweden)

Cemil Kavalci

2011-01-01

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

Scapula fracture incidence in reverse total shoulder arthroplasty using screws above or below metaglene central cage: clinical and biomechanical outcomes.

Science.gov (United States)

Kennon, Justin C; Lu, Caroline; McGee-Lawrence, Meghan E; Crosby, Lynn A

2017-06-01

Reverse total shoulder arthroplasty (RTSA) is a viable treatment option for rotator cuff tear arthropathy but carries a complication risk of scapular fracture. We hypothesized that using screws above the central glenoid axis for metaglene fixation creates a stress riser contributing to increased scapula fracture incidence. Clinical type III scapular fracture incidence was determined with screw placement correlation: superior screw vs. screws placed exclusively below the glenoid midpoint. Cadaveric RTSA biomechanical modeling was employed to analyze scapular fractures. We reviewed 318 single-surgeon single-implant RTSAs with screw correlation to identify type III scapular fractures. Seventeen cadaveric scapula specimens were matched for bone mineral density, metaglenes implanted, and fixation with 2 screw configurations: inferior screws alone (group 1 INF ) vs. inferior screws with one additional superior screw (group 2 SUP ). Biomechanical load to failure was analyzed. Of 206 patients, 9 (4.4%) from the superior screw group experienced scapula fractures (type III); 0 fractures (0/112; 0%) were identified in the inferior screw group. Biomechanically, superior screw constructs (group 2 SUP ) demonstrated significantly (P < .05) lower load to failure (1077 N vs. 1970 N) compared with constructs with no superior screws (group 1 INF ). There was no significant age or bone mineral density discrepancy. Clinical scapular fracture incidence significantly decreased (P < .05) for patients with no screws placed above the central cage compared with patients with superior metaglene screws. Biomechanical modeling demonstrates significant construct compromise when screws are used above the central cage, fracturing at nearly half the ultimate load of the inferior screw constructs. We recommend use of inferior screws, all positioned below the central glenoid axis, unless necessary to stabilize the metaglene construct. Copyright © 2016 Journal of Shoulder and Elbow Surgery

Energy management for cost reduction in the production. TEEM - Total Energy Efficiency Management; Energiemanagement zur Kostensenkung in der Produktion. TEEM - Total Energy Efficiency Management

Energy Technology Data Exchange (ETDEWEB)

Westkaemper, Engelbert; Verl, Alexander (eds.)

2009-07-01

Within the workshop of the Fraunhofer Institute for Manufacturing Engineering and Automation IPA (Stuttgart, Federal Republic of Germany) at 6th October, 2009, in Stuttgart the following lectures were held: (1) Presentation of Fraunhofer Institute for Manufacturing Engineering and Automation IPA (Engelbert Westkaemper); (2) TEEM - Total Energy Efficiency Management - ''With energy management to an energy efficient production'' (Alexander Schloske); (3) DIN EN 16001 Introduction of an energy management system - utilization and advantages for companies (Sylvia Wahren); (4) Analysis of the energy efficiency with power flow - Support and implementation at factory planning and optimization of production (Klaus Erlach); (5) Total Energy Efficiency Management - Approaches at the company Kaercher in injection moulding for example (Axel Leschtar); (6) Modelling the embodied product energy (Shahin Rahimifard); (7) Acquisition of energy data in the production - Technologies and possibilities (Joachim Neher); (8) Active energy management by means of an ''energy control centre'' - Analysis of the real situation and upgrading measures in the production using coating plants as an example (Wolfgang Klein); (9) Visualisation and simulation of energy values in the digital factory (Carmen Constantinescu, Axel Bruns).

Determining fracture energy parameters of concrete from the modified compact tension test

Czech Academy of Sciences Publication Activity Database

Canteli, A.; Castañón, L.; Nieto, B.; Lozano, M.; Holušová, Táňa; Seitl, Stanislav

2014-01-01

Roč. 30, OCT (2014), s. 383-393 ISSN 1971-8993 R&D Projects: GA MŠk(CZ) EE2.3.20.0214 Grant - others:interní podpora AV ČR(CZ) M100411204 Institutional support: RVO:68081723 Keywords : Concrete fracture energy * Modified compact tension test * Concrete * Numerical simulation Subject RIV: JL - Materials Fatigue, Friction Mechanics

Seismic Characterizations of Fractures: Dynamic Diagnostics

Science.gov (United States)

Pyrak-Nolte, L. J.

2017-12-01

Fracture geometry controls fluid flow in a fracture, affects mechanical stability and influences energy partitioning that affects wave scattering. Our ability to detect and monitor fracture evolution is controlled by the frequency of the signal used to probe a fracture system, i.e. frequency selects the scales. No matter the frequency chosen, some set of discontinuities will be optimal for detection because different wavelengths sample different subsets of fractures. The select subset of fractures is based on the stiffness of the fractures which in turn is linked to fluid flow. A goal is obtaining information from scales outside the optimal detection regime. Fracture geometry trajectories are a potential approach to drive a fracture system across observation scales, i.e. moving systems between effective medium and scattering regimes. Dynamic trajectories (such as perturbing stress, fluid pressure, chemical alteration, etc.) can be used to perturb fracture geometry to enhance scattering or give rise to discrete modes that are intimately related to the micro-structural evolution of a fracture. However, identification of these signal features will require methods for identifying these micro-structural signatures in complicated scattered fields. Acknowledgment: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Geosciences Research Program under Award Number (DE-FG02-09ER16022).

Profile and procedures for fractures among 1323 fracture patients from the 2010 Yushu earthquake, China.

Science.gov (United States)

Kang, Peng; Tang, Bihan; Liu, Yuan; Liu, Xu; Shen, Yan; Liu, Zhipeng; Yang, Hongyang; Zhang, Lulu

2016-11-01

The injuries caused by earthquakes are often complex and of various patterns. Our study included all fracture inpatients from the Yushu earthquake (1323 in total), to learn more about the incidence and distribution of fractures during earthquakes. A retrospective study of the clinical characteristics of hospitalized fracture patients after the 2010 Yushu earthquake was conducted from December 20 to 25, 2010.We reviewed medical records of hospitalized patients who had been evacuated from the Yushu earthquake area between April 14 and June 15, 2010, from 57 hospitals, and also reviewed more than 100 documents assembled from daily medical rescue and disease prevention reports submitted by the frontline rescue organizations. In total, 78.0% of fracture patients were admitted to the hospital within 3 days after the earthquake. There were 1323 patients who presented with 1539 fractures. The most common fracture occurred in the lower limbs, followed by spinal, pelvic, and shoulder-upper limb fractures. The end of the thoracic vertebra and the lumbar vertebra were the high-risk sites for vertebral fractures. A total of 38 patients became paraplegic. A 2-level spatial clustering was detected among the 193 patients presenting with 2 fractures. Analysis profiles of the injuries and clinical features of patients with earthquake-related fractures will positively impact rescue efforts and the treatment of fracture injuries caused by possible future natural disasters. We should assemble orthopedic-related medications and surgical equipment, and allocate them promptly after a major earthquake. Copyright © 2016 Elsevier Inc. All rights reserved.

High energy injury is a risk factor for preoperative venous thromboembolism in the patients with hip fractures: A prospective observational study.

Science.gov (United States)

Park, Jin Sup; Jang, Jae Hoon; Park, Ki Young; Moon, Nam Hoon

2018-06-01

The purpose of this study was to identify the incidence of preoperative venous thromboembolism (VTE), and determine if high energy hip fracture affects preoperative VTE occurrence. Three-hundred nine patients (244 low and 61 high energy injuries) treated between March 2015 and March 2017 were included in this study. Indirect multidetector computed tomographic venography for the detection of preoperative VTE was performed at admission. The incidence of preoperative VTE was compared between high and low energy injury hip fractures. Logistic regression analysis was used to identify independent risk factors for preoperative VTE. The overall incidence of preoperative VTE was 18.4% (56 of 305 patients). Preoperative VTE was identified in 17 (27.9%) and 39 (16.0%) patients in the high and low energy injury groups, respectively (p = 0.034). Multivariate logistic regression analysis showed that high energy injury, history of VTE, and myeloproliferative disease were significant predictive factors of preoperative VTE (OR = 2.451; 95% CI = 1.227-4.896, OR = 11.174; 95% CI = 3.500-35.673, OR = 6.936; 95% CI = 1.641-29.321, respectively) CONCLUSION: Because high energy hip fracture is significantly associated with preoperative VTE occurrence, preoperative evaluation and proper thromboprophylaxis should be performed for patients with a high-energy hip fracture. Copyright © 2018 Elsevier Ltd. All rights reserved.

Differences in Classification Between Mono- and Polytrauma and Low- and High-Energy Trauma Patients With an Ankle Fracture: A Retrospective Cohort Study

NARCIS (Netherlands)

Briet, Jan Paul; Houwert, Roderick Marijn; Smeeing, Diederik P. J.; Dijkgraaf, Marcel G. W.; Verleisdonk, Egbert Jan; Leenen, Luke P. H.; Hietbrink, Falco

2017-01-01

Although fracture type and treatment options for ankle fractures are well defined, the differences between mono- and polytrauma patients and low- and high-energy trauma have not been addressed. The aim of the present study was to compare the fracture type and trauma mechanism between mono- and

Detection of Bone Marrow Edema in Nondisplaced Hip Fractures: Utility of a Virtual Noncalcium Dual-Energy CT Application.

Science.gov (United States)

Kellock, Trenton T; Nicolaou, Savvas; Kim, Sandra S Y; Al-Busaidi, Sultan; Louis, Luck J; O'Connell, Tim W; Ouellette, Hugue A; McLaughlin, Patrick D

2017-09-01

Purpose To quantify the sensitivity and specificity of dual-energy computed tomographic (CT) virtual noncalcium images in the detection of nondisplaced hip fractures and to assess whether obtaining these images as a complement to bone reconstructions alters sensitivity, specificity, or diagnostic confidence. Materials and Methods The clinical research ethics board approved chart review, and the requirement to obtain informed consent was waived. The authors retrospectively identified 118 patients who presented to a level 1 trauma center emergency department and who underwent dual-energy CT for suspicion of a nondisplaced traumatic hip fracture. Clinical follow-up was the standard of reference. Three radiologists interpreted virtual noncalcium images for traumatic bone marrow edema. Bone reconstructions for the same cases were interpreted alone and then with virtual noncalcium images. Diagnostic confidence was rated on a scale of 1 to 10. McNemar, Fleiss κ, and Wilcoxon signed-rank tests were used for statistical analysis. Results Twenty-two patients had nondisplaced hip fractures and 96 did not have hip fractures. Sensitivity with virtual noncalcium images was 77% and 91% (17 and 20 of 22 patients), and specificity was 92%-99% (89-95 of 96 patients). Sensitivity increased by 4%-5% over that with bone reconstruction images alone for two of the three readers when both bone reconstruction and virtual noncalcium images were used. Specificity remained unchanged (99% and 100%). Diagnostic confidence in the exclusion of fracture was improved with combined bone reconstruction and virtual noncalcium images (median score: 10, 9, and 10 for readers 1, 2, and 3, respectively) compared with bone reconstruction images alone (median score: 9, 8, and 9). Conclusion When used as a supplement to standard bone reconstructions, dual-energy CT virtual noncalcium images increased sensitivity for the detection of nondisplaced traumatic hip fractures and improved diagnostic confidence in

Energy release rate analysis on the interface cracks of enamel-cement-bracket fracture using virtual crack closure technique

Science.gov (United States)

Samshuri, S. F.; Daud, R.; Rojan, M. A.; Mat, F.; Basaruddin, K. S.; Hassan, R.

2017-10-01

This paper presents the energy method to evaluate fracture behavior of enamel-cement-bracket system based on cement thickness. Finite element (FE) model of enamel-cement-bracket was constructed by using ANSYS Parametric Design Language (APDL). Three different thickness were used in this study, 0.05, 0.2, and 0.271 mm which assigned as thin, medium and thick for both enamel-cement and cement bracket interface cracks. Virtual crack closure technique (VCCT) was implemented as a simulation method to calculated energy release rate (ERR). Simulation results were obtained for each thickness are discussed by using Griffith’s energy balance approach. ERR for thin thickness are found to be the lowest compared to medium and thick. Peak value of ERR also showed a significant different between medium and thick thickness. Therefore, weakest bonding occurred at low cement thickness because less load required to produce enough energy to detach the bracket. For medium and thick thickness, both increased rapidly in energy value at about the mid-point of the enamel-cement interface. This behavior occurred because of the increasing in mechanical and surface energy when the cracks are increasing. However, result for thick thickness are higher at mid-point compared to thin thickness. In conclusion, fracture behavior of enamel cracking process for medium most likely the safest to avoid enamel fracture and withstand bracket debonding.

Implicit fracture modelling in FLAC3D: Assessing the behaviour of fractured shales, carbonates and other fractured rock types

NARCIS (Netherlands)

Osinga, S.; Pizzocolo, F.; Veer, E.F. van der; Heege, J.H. ter

2016-01-01

Fractured rocks play an important role in many types of petroleum and geo-energy operations. From fractured limestone reservoirs to unconventionals, understanding the geomechanical behaviour and the dynamically coupled (dual) permeability system is paramount for optimal development of these systems.

Total energy consumption in Finland increased by one percent

International Nuclear Information System (INIS)

Timonen, L.

2000-01-01

The total energy consumption in Finland increased by less than a percent in 1999. The total energy consumption in 1999 was 1310 PJ corresponding to about 31 million toe. The electric power consumption increased moderately by 1.6%, which is less than the growth of the gross national product (3.5%). The final consumption of energy grew even less, only by 0.5%. Import of electric power increased by 19% in 1999. The import of electric power was due to the availability of low-priced electric power on the Nordic electricity markets. Nuclear power generation increased by 5% and the consumption of wood-based fuels by 3%. The increment of the nuclear power generation increased because of the increased output capacity and good operability of the power plants. Wind power production doubles, but the share of it in the total energy consumption is only about 0.01%. The peat consumption decreased by 12% and the consumption of hydroelectric power by 15%. The decrease in production of hydroelectric power was compensated by an increase import of electric power. The consumption of fossil fuels, coal, oil and natural gas remained nearly the same as in 1998. The gasoline consumption, however, decreased, but the consumption of diesel oil increased due to the increased road transport. The share of the fossil fuels was nearly half of the total energy consumption. The consumption of renewable energy sources remained nearly the same, in 23% if the share of peat is excluded, and in 30% if the share of peat is included. Wood-based fuels are the most significant type of renewable fuels. The share of them in 1999 was over 80% of the total usage of the renewable energy sources. The carbon dioxide emissions in Finland decreased in 1999 by 1.0 million tons. The total carbon dioxide emissions were 56 million tons. The decrease was mainly due to the decrease of the peat consumption. The final consumption of energy increased by 0.5%, being hence about 1019 PJ. Industry is the main consumer of energy

Optimized design of total energy systems: The RETE project

Science.gov (United States)

Alia, P.; Dallavalle, F.; Denard, C.; Sanson, F.; Veneziani, S.; Spagni, G.

1980-05-01

The RETE (Reggio Emilia Total Energy) project is discussed. The total energy system (TES) was developed to achieve the maximum quality matching on the thermal energy side between plant and user and perform an open scheme on the electrical energy side by connection with the Italian electrical network. The most significant qualitative considerations at the basis of the plant economic energy optimization and the selection of the operating criterion most fitting the user consumption characteristics and the external system constraints are reported. The design methodology described results in a TES that: in energy terms achieves a total efficiency evaluated on a yearly basis to be equal to about 78 percent and a fuel saving of about 28 percent and in economic terms allows a recovery of the investment required as to conventional solutions, in about seven years.

Delayed cementless total hip arthroplasty for neglected dislocation of hip combined with complex acetabular fracture and deficient bone stock

Directory of Open Access Journals (Sweden)

Gavaskar Ashok S

2012-12-01

Full Text Available 【Abstract】Total hip arthroplasty (THA for an un-treated acetabular fracture is technically challenging and the long-term result is not so favorable. A 45-year-old fe-male patient with untreated column and comminuted poste-rior wall fracture of the acetabulum was treated in our insti-tution by reconstruction of the posterior wall using iliac strut autograft and plate stabilization of the posterior col-umn with cancellous grafting and cementless THA in a single stage. At 3 years’ follow-up, the patient was independently mobile without limb length discrepancy. Radiological evalu-ation showed well integrated components and bone grafts. No evidence of aseptic loosening or osteolysis was found. This report aims to emphasize that bony acetabular recon-struction allows the use of primary hip components, which improves prosthesis longevity and preserves bone stock for a future revision. Key words: Acetabulum; Fractures, bone; Hip dislocation; Arthroplasty, replacement, hip

Atomic resonances above the total ionization energy

International Nuclear Information System (INIS)

Doolen, G.

1975-01-01

A rigorous result obtained using the theory associated with dilatation analytic potentials is that by performing a complex coordinate rotation, r/subj/ → r/subj/e/subi//sup theta/, on a Hamiltonian whose potential involves only pairwise Coulombic interactions, one can show that when theta = π/2, no complex eigenvalues (resonances) appear whose energies have a real part greater than the total ionization energy of the atomic system. This appears to conflict with experimental results of Walton, Peart, and Dolder, who find resonance behavior above the total ionization energy of the H -- system and also the theoretical stabilization results of Taylor and Thomas for the same system. A possible resolution of this apparent conflict is discussed and a calculation to check its validity is proposed

Extracorporeal shock wave treatment of non- or delayed union of proximal metatarsal fractures.

Science.gov (United States)

Alvarez, Richard G; Cincere, Brandon; Channappa, Chandra; Langerman, Richard; Schulte, Robert; Jaakkola, Juha; Melancon, Keith; Shereff, Michael; Cross, G Lee

2011-08-01

Nonunion or delayed union of fractures in the proximal aspect of metatarsals 1 to 4 and Zone 2 of the fifth metatarsal were treated by high energy extracorporeal shock wave treatment (ESWT) to study the safety and efficacy of this method of treatment in a FDA study of the Ossatron device. In a prospective single-arm, multi-center study, 34 fractures were treated in 32 patients (two subjects had two independent fractures) with ESWT. All fractures were at least 10 (range, 10 to 833) weeks after injury, with a median of 23 weeks. ESWT application was conducted using a protocol totaling 2,000 shocks for a total energy application of approximately 0.22 to 0.51 mJ/mm2 per treatment. The mean ESWT application time for each of the treatments was 24.6 +/- 16.6 minutes, and anesthesia time averaged 27.1 +/- 10.4 minutes. All subjects were followed for 1 year after treatment at intervals of 12 weeks, 6, 9, and 12 months. The overall success rate at the 12-week visit was 71% with low complications, significant pain improvement as well as improvement on the SF-36. The success/fail criteria was evaluated again at the 6- and 12-month followup, showing treatment success rates of 89% (23/26) and 90% (18/20), respectively. The most common adverse event was swelling in the foot, reported by five subjects (15.6%). High-energy ESWT appears to be effective and safe in patients for treatment of nonunion or a delayed healing of a proximal metatarsal, and in fifth metatarsal fractures in Zone 2.

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.

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

Vertebral Fractures and Spondylosis in Men - Original Investigation

Directory of Open Access Journals (Sweden)

Selmin Gülbahar

2008-04-01

Full Text Available Aim: The aim of this study was to investigate the relationship between vertebral fractures and spondylosis and bone mineral density in men older than 60 years. Material and Method: Thirty-two men with back and low back pain aged over 60 years were included into the study. Thoracic and lumbar spine radiographs were taken and, anterior, central and posterior heights of each vertebral body from T4 to L5 was measured and than the number of vertebral fractures was assessed. Osteophyte and disc scores were used for evaluation of spondylosis. Bone mineral density was measured by dual-energy-X-ray absorptiometry. Measurements were obtained from lumbar vertebrae and proximal femoral region. Results: Significant positive correlations were found between vertebral fracture and osteophyte score and bone mineral density of total femoral region. When osteophyte score and total femoral bone mineral density were taken into consideration, there were no significant correlations between other parameters and vertebral fracture. Significant positive correlations were observed between osteophyte score and bone mineral density and t scores of L1-4. Also there were significant positive correlations between disc score and both bone mineral density and t scores of L1-4. Significant positive correlation was also found between femoral bone density and body weight. Conclusion: Finally, lumbar bone mineral density increases with spinal degenerative changes, but the increase in bone mineral density can not prevent sub clinic vertebral fractures. Especially, in the men who have intensive spinal degenerative changes, the measurement of lumbar bone mineral density is not enough for determining the fracture risk. Measurement of femoral bone mineral density and evaluation of clinic risk factors are more important for determining the fracture risk. (From the World of Osteoporosis 2008;14:1-6

Low serum magnesium levels are associated with increased risk of fractures: a long-term prospective cohort study.

Science.gov (United States)

Kunutsor, Setor Kwadzo; Whitehouse, Michael Richard; Blom, Ashley William; Laukkanen, Jari Antero

2017-07-01

Magnesium, which is an essential trace element that plays a key role in several cellular processes, is a major component of bone; however, its relationship with risk of major bone fractures is uncertain. We aimed to investigate the association of baseline serum magnesium concentrations with risk of incident fractures. We analyzed data on 2245 men aged 42-61 years in the Kuopio Ischemic Heart Disease prospective cohort study, with the assessment of serum magnesium measurements and dietary intakes made at baseline. Hazard ratios [95% confidence intervals (CI)] for incident total (femoral, humeral, and forearm) and femoral fractures were assessed. During a median follow-up of 25.6 years, 123 total fractures were recorded. Serum magnesium was non-linearly associated with risk of total fractures. In age-adjusted Cox regression analysis, the hazard ratio (HR) (95% CIs) for total fractures in a comparison of the bottom quartile versus top quartile of magnesium concentrations was 2.10 (1.30-3.41), which persisted on adjustment for several established risk factors 1.99 (1.23-3.24). The association remained consistent on further adjustment for renal function, socioeconomic status, total energy intake, and several trace elements 1.80 (1.10-2.94). The corresponding adjusted HRs for femoral fractures were 2.56 (1.38-4.76), 2.43 (1.30-4.53) and 2.13 (1.13-3.99) respectively. There was no evidence of an association of dietary magnesium intake with risk of any fractures. In middle-aged Caucasian men, low serum magnesium is strongly and independently associated with an increased risk of fractures. Further research is needed to assess the potential relevance of serum magnesium in the prevention of fractures.

OPTIMIZATION OF INFILL DRILLING IN NATURALLY-FRACTURED TIGHT-GAS RESERVOIRS

Energy Technology Data Exchange (ETDEWEB)

Lawrence W. Teufel; Her-Yuan Chen; Thomas W. Engler; Bruce Hart

2004-05-01

A major goal of industry and the U.S. Department of Energy (DOE) fossil energy program is to increase gas reserves in tight-gas reservoirs. Infill drilling and hydraulic fracture stimulation in these reservoirs are important reservoir management strategies to increase production and reserves. Phase II of this DOE/cooperative industry project focused on optimization of infill drilling and evaluation of hydraulic fracturing in naturally-fractured tight-gas reservoirs. The cooperative project involved multidisciplinary reservoir characterization and simulation studies to determine infill well potential in the Mesaverde and Dakota sandstone formations at selected areas in the San Juan Basin of northwestern New Mexico. This work used the methodology and approach developed in Phase I. Integrated reservoir description and hydraulic fracture treatment analyses were also conducted in the Pecos Slope Abo tight-gas reservoir in southeastern New Mexico and the Lewis Shale in the San Juan Basin. This study has demonstrated a methodology to (1) describe reservoir heterogeneities and natural fracture systems, (2) determine reservoir permeability and permeability anisotropy, (3) define the elliptical drainage area and recoverable gas for existing wells, (4) determine the optimal location and number of new in-fill wells to maximize economic recovery, (5) forecast the increase in total cumulative gas production from infill drilling, and (6) evaluate hydraulic fracture simulation treatments and their impact on well drainage area and infill well potential. Industry partners during the course of this five-year project included BP, Burlington Resources, ConocoPhillips, and Williams.

The Use of Trust Regions in Kohn-Sham Total Energy Minimization

International Nuclear Information System (INIS)

Yang, Chao; Meza, Juan C.; Wang, Lin-wang

2006-01-01

The Self Consistent Field (SCF) iteration, widely used for computing the ground state energy and the corresponding single particle wave functions associated with a many-electron atomistic system, is viewed in this paper as an optimization procedure that minimizes the Kohn-Sham total energy indirectly by minimizing a sequence of quadratic surrogate functions. We point out the similarity and difference between the total energy and the surrogate, and show how the SCF iteration can fail when the minimizer of the surrogate produces an increase in the KS total energy. A trust region technique is introduced as a way to restrict the update of the wave functions within a small neighborhood of an approximate solution at which the gradient of the total energy agrees with that of the surrogate. The use of trust region in SCF is not new. However, it has been observed that directly applying a trust region based SCF(TRSCF) to the Kohn-Sham total energy often leads to slow convergence. We propose to use TRSCF within a direct constrained minimization(DCM) algorithm we developed in dcm. The key ingredients of the DCM algorithm involve projecting the total energy function into a sequence of subspaces of small dimensions and seeking the minimizer of the total energy function within each subspace. The minimizer of a subspace energy function, which is computed by TRSCF, not only provides a search direction along which the KS total energy function decreases but also gives an optimal 'step-length' that yields a sufficient decrease in total energy. A numerical example is provided to demonstrate that the combination of TRSCF and DCM is more efficient than SCF

Fratura periprotética da tíbia combinada com fratura de fadiga da haste tibial de artroplastia total do joelho Tibial periprosthetic fracture combined with tibial stem stress fracture from total knee arthroplasty

Directory of Open Access Journals (Sweden)

Fernando Fonseca

2011-01-01

Full Text Available As complicações das artroplastias totais do joelho relacionadas com o próprio material são muito raras, exceto o desgaste do polietileno. Neste artigo os autores reportam o caso de uma paciente do sexo feminino de 58 anos referenciada ao pronto-socorro do nosso hospital por uma fratura periprotética tibial (tipo I da classificação da Mayo Clinic. Uma observação mais cuidadosa mostrou a presença concomitante da referida fratura da tíbia associada à fratura de fadiga da haste tibial. A prótese com a haste foi remetida a um laboratório de biomecânica independente onde foi avaliada e efetuada uma reconstrução com uso de sistema de elementos finitos em CAD de modo a verificar a existência de algum defeito de fabricação e as eventuais causas para o sucedido. Depois de avaliadas diversas hipóteses, concluiu-se que a fratura do material foi provocada por uma sobrecarga na zona de transição prato/haste secundária à falência óssea prévia (fratura. Da avaliação do caso ressalta-se novamente a necessidade de efetuar uma avaliação adequada da mineralização óssea e, em caso de dúvida, utilizar uma haste longa.Total knee arthroplasty complications related to the prosthetic material are very rare, except for polyethylene wear. We report the case of a 58-year-old woman who came to the emergency service of our hospital with a periprosthetic tibial fracture (Mayo Clinic type I. Careful examination showed that this fracture was concomitantly associated with a tibial stem fatigue fracture. The prosthesis and the stem were sent to an independent biomechanics laboratory for evaluation. A finite-element CAD system was used to make a reconstruction, so as to ascertain whether there had been any manufacturing defect and what the causes of the event might have been. After evaluation of several hypotheses, it was concluded that the fracture in the prosthetic material had been caused by overloading at the plate/stem transition zone

Assessment of the Impacts of Hydraulic Fracturing at Bakken on Regional Water Resources

Science.gov (United States)

Lin, Z.; Lin, T.; Lim, S.; Borders, M.

2015-12-01

Unconventional oil production at the Bakken Shale of western North Dakota increased more than ten-fold from 2008 to 2014. Although unconventional oil production uses less water than conventional oil production per unit of energy, the cumulative water needs for unconventional oil production due to multiple drilling and fracturing operations may be locally or temporally significant. We collected and analyzed the data for a total of 8453 horizontal wells developed at Bakken in western North Dakota during 2007-2014. The hydraulic fracturing activities mainly occurred in a core area of four counties, including Dunn, McKenzie, Mountrail, and Williams. The annual total water used for hydraulic fracking in western North Dakota increased from 302 ac-ft in 2007 to 21,605 ac-ft in 2014, by more than 70 times in 8 years. The four-county core area accounted for about 90% of total hydraulic fracturing water use in western North Dakota. Compared to the total water uses of all types, hydraulic fracturing water use in the four-county core area accounted for 0.7% in 2007 and 43.1% in 2014. Statewide, this percentage increased from 0.1% to 6.1% in the same time period. As horizontal drilling and hydraulic fracturing technologies matured for unconventional oil development at Bakken, the total depth and the total length of laterals per well seemed to reach an optimal value in the last four years (2011-2014). However, the number of fracturing stages and the volume of fracking water used per completion are still on the rise. The average water use per well increased from about 1.7 ac-ft in 2007 to 11.4 ac-ft in 2014. Correspondingly, the water intensity (volume of fracking water used per foot of laterals) increased from 67 gallon/ft in 2007 to about 372 gallon/ft 2014. The results helped us better understand the environmental impacts of hydraulic fracturing at Bakken and better manage the water resources in the region.

Differences in Classification Between Mono- and Polytrauma and Low- and High-Energy Trauma Patients With an Ankle Fracture : A Retrospective Cohort Study

NARCIS (Netherlands)

Briet, Jan Paul; Houwert, Roderick Marijn; Smeeing, Diederik P J; Dijkgraaf, Marcel G. W.; Verleisdonk, Egbert Jan M M; Leenen, Luke P H; Hietbrink, Falco

2017-01-01

Although fracture type and treatment options for ankle fractures are well defined, the differences between mono- and polytrauma patients and low- and high-energy trauma have not been addressed. The aim of the present study was to compare the fracture type and trauma mechanism between mono- and

Hypersolidus geothermal energy from the moving freeze-fracture-flow boundary

Science.gov (United States)

Carrigan, Charles; Eichelberger, John; Sigmundsson, Freysteinn; Papale, Paolo; Sun, Yunwei

2014-05-01

Rhyolitic magmas at low pressure undergo much of their crystallization over a small temperature interval just above the solidus. This hypersolidus material has a high energy density and effective heat capacity because of stored heat of crystallization, yet may sustain fractures and therefore admit heat exchange with fluids because of its interlocking crystal framework. Rhyolitic magmas emplaced near the liquidus should at first cool rapidly, owing to internal convection, modest crystallization with declining temperature, and extreme temperature gradients at their boundaries. However, once the solidus is approached the rapid rise in effective heat capacity should result in low temperature gradients and rates of heat flow within the bodies. They are suspended for a time in the hypersolidus state. Prodigious quantities of heat can be released from these thermal masses by hydrothermal systems, natural or perhaps stimulated, fracturing their way inward from the margins. The fracture front drives the solidus isotherm ahead of it. Heat of crystallization in front of the advancing solidus is transferred across the thin, moving boundary zone to the external fluid, which advects it away. Once the material is below (outboard of) the solidus, it behaves as normal rock and cools rapidly, having a heat capacity only about 20% that of water. Variations on this theme were published by Lister (1974) for mid-ocean ridges, Hardee (1980) for lava lakes, and Bjornsson et al (1982) for Grimsvotn and Heimaey, who cited possible geothermal energy exploitiation. This scenario is consistent with a number of observations: 1. The geophysical rarity of imaging mostly liquid magma in the shallow crust, despite common petrologic evidence that silicic magma has undergone shallow storage. 2. More common imaging of "partial melt" volumes, whose inferred properties suggest some, but not dominant proportion of melt. 3. Evidence that pure-melt rhyolitic eruptions may have drained relatively shallow

The Fracture Influence on the Energy Loss of Compressed Air Energy Storage in Hard Rock

Directory of Open Access Journals (Sweden)

Hehua Zhu

2015-01-01

Full Text Available A coupled nonisothermal gas flow and geomechanical numerical modeling is conducted to study the influence of fractures (joints on the complex thermohydromechanical (THM performance of underground compressed air energy storage (CAES in hard rock caverns. The air-filled chamber is modeled as porous media with high porosity, high permeability, and high thermal conductivity. The present analysis focuses on the CAES in hard rock caverns at relatively shallow depth, that is, ≤100 m, and the pressure in carven is significantly higher than ambient pore pressure. The influence of one discrete crack and multiple crackson energy loss analysis of cavern in hard rock media are carried out. Two conditions are considered during each storage and release cycle, namely, gas injection and production mass being equal and additional gas injection supplemented after each cycle. The influence of the crack location, the crack length, and the crack open width on the energy loss is studied.

High-accuracy phase-field models for brittle fracture based on a new family of degradation functions

Science.gov (United States)

Sargado, Juan Michael; Keilegavlen, Eirik; Berre, Inga; Nordbotten, Jan Martin

2018-02-01

Phase-field approaches to fracture based on energy minimization principles have been rapidly gaining popularity in recent years, and are particularly well-suited for simulating crack initiation and growth in complex fracture networks. In the phase-field framework, the surface energy associated with crack formation is calculated by evaluating a functional defined in terms of a scalar order parameter and its gradients. These in turn describe the fractures in a diffuse sense following a prescribed regularization length scale. Imposing stationarity of the total energy leads to a coupled system of partial differential equations that enforce stress equilibrium and govern phase-field evolution. These equations are coupled through an energy degradation function that models the loss of stiffness in the bulk material as it undergoes damage. In the present work, we introduce a new parametric family of degradation functions aimed at increasing the accuracy of phase-field models in predicting critical loads associated with crack nucleation as well as the propagation of existing fractures. An additional goal is the preservation of linear elastic response in the bulk material prior to fracture. Through the analysis of several numerical examples, we demonstrate the superiority of the proposed family of functions to the classical quadratic degradation function that is used most often in the literature.

Economics of total energy schemes in the liberalised European energy market

Science.gov (United States)

Lampret, Peter

This thesis is concerned with the liberalisation of the European Energy markets and the affects this has had on total energy systems. The work concentrates on a number of case studies all of which are located in the area surrounding Gelsenkirchen - Bottrop - Gladbeck, the centre of the Ruhr region of Germany.The thesis describes briefly how the legislation of the parliament of the extended European Union has been interpreted and enacted into German legislation and its affects on production, transport, sales and customers. Primarily the legislation has been enacted to reduce energy costs by having a competitive market while enabling security of supply. The legislation whose development has accelerated since 1999 can lead to negative effects and these have been highlighted for the case studies chosen.The legislation and technological advances, each of them successful by themselves, do not provide the expected reduction of carbon dioxide emissions when applied to total energy system. The introduction of human behaviour as a missing link makes the problems evident and gives a theoretical basis to overcome these problems. The hypothesis is proven by eight detailed research projects and four concisely described ones.The base of the research is the experience gained on approximately 1,000 operation years of the simplest total energy system, that of centralised heating. This experience is transferred to different solutions for total energy systems and their economics in combination with the changing legislation and observation of human behaviour.The variety of topics of the case studies includes the production of heat by boiler, solar or combined heat and power and the use of fuel cells. Additionally the transfer of heat, at the place of demand is considered, either as an individual boiler in a building or as de-centralised district heating.The various results of these projects come together in a final project which covers four different heating systems in identical

Canine total knee replacement performed due to osteoarthritis subsequent to distal femur fracture osteosynthesis: two-year objective outcome.

Science.gov (United States)

Eskelinen, E V; Liska, W D; Hyytiäinen, H K; Hielm-Björkman, A

2012-01-01

A 27-kg German Shorthaired Pointer was referred for evaluation due to the complaint of left pelvic limb lameness and signs of pain in the left stifle joint. Radiographs revealed signs of a healed supracondylar femoral fracture that had been previously repaired at another hospital with an intramedullary pin and two cross pins. In addition, there were signs of severe osteoarthritis (OA). The OA had been managed medically with administration of carprofen and nutraceuticals for nine months without any improvement. Left total knee replacement (TKR) surgery was performed to alleviate signs of pain. The patient was assessed preoperatively and at six months, one year, and two years after surgery using radiology, force platform analysis of gait, thigh circumference measures, goniometry, and lameness evaluation. Following surgery, the dog resumed normal activity without any signs of pain and a good quality of life at 3.5 months. Force plate analysis found that peak vertical force on the TKR limb was 85.7% of the normal contralateral limb after two years. Total knee replacement was a successful treatment to manage knee OA associated with a healed distal femoral fracture and internal fixation in this dog.

Statistical properties of kinetic and total energy densities in reverberant spaces

DEFF Research Database (Denmark)

Jacobsen, Finn; Molares, Alfonso Rodriguez

2010-01-01

Many acoustical measurements, e.g., measurement of sound power and transmission loss, rely on determining the total sound energy in a reverberation room. The total energy is usually approximated by measuring the mean-square pressure (i.e., the potential energy density) at a number of discrete....... With the advent of a three-dimensional particle velocity transducer, it has become somewhat easier to measure total rather than only potential energy density in a sound field. This paper examines the ensemble statistics of kinetic and total sound energy densities in reverberant enclosures theoretically...... positions. The idea of measuring the total energy density instead of the potential energy density on the assumption that the former quantity varies less with position than the latter goes back to the 1930s. However, the phenomenon was not analyzed until the late 1970s and then only for the region of high...

Fracture properties of hydrogenated amorphous silicon carbide thin films

International Nuclear Information System (INIS)

Matsuda, Y.; King, S.W.; Bielefeld, J.; Xu, J.; Dauskardt, R.H.

2012-01-01

The cohesive fracture properties of hydrogenated amorphous silicon carbide (a-SiC:H) thin films in moist environments are reported. Films with stoichiometric compositions (C/Si ≈ 1) exhibited a decreasing cohesive fracture energy with decreasing film density similar to other silica-based hybrid organic–inorganic films. However, lower density a-SiC:H films with non-stoichiometric compositions (C/Si ≈ 5) exhibited much higher cohesive fracture energy than the films with higher density stoichiometric compositions. One of the non-stoichiometric films exhibited fracture energy (∼9.5 J m −2 ) greater than that of dense silica glasses. The increased fracture energy was due to crack-tip plasticity, as demonstrated by significant pileup formation during nanoindentation and a fracture energy dependence on film thickness. The a-SiC:H films also exhibited a very low sensitivity to moisture-assisted cracking compared with other silica-based hybrid films. A new atomistic fracture model is presented to describe the observed moisture-assisted cracking in terms of the limited Si-O-Si suboxide bond formation that occurs in the films.

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.

Fracture Energy of High-Strength Concrete in Compression

DEFF Research Database (Denmark)

Dahl, H.; Brincker, Rune

1989-01-01

is essential for understanding the fracture mechanism of concrete in compression. In this paper a series of tests is reported, carried out for the purpose of studying the fracture mechanical properties of concrete in compression. Including the measurement and study of the descending branch, a new experimental...

Fracture mechanics safety approaches

International Nuclear Information System (INIS)

Roos, E.; Schuler, X.; Eisele, U.

2004-01-01

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

SpineAnalyzer™ is an accurate and precise method of vertebral fracture detection and classification on dual-energy lateral vertebral assessment scans

International Nuclear Information System (INIS)

Birch, C.; Knapp, K.; Hopkins, S.; Gallimore, S.; Rock, B.

2015-01-01

Osteoporotic fractures of the spine are associated with significant morbidity, are highly predictive of hip fractures, but frequently do not present clinically. When there is a low to moderate clinical suspicion of vertebral fracture, which would not justify acquisition of a radiograph, vertebral fracture assessment (VFA) using Dual-energy X-ray Absorptiometry (DXA) offers a low-dose opportunity for diagnosis. Different approaches to the classification of vertebral fractures have been documented. The aim of this study was to measure the precision and accuracy of SpineAnalyzer™, a quantitative morphometry software program. Lateral vertebral assessment images of 64 men were analysed using SpineAnalyzer™ and standard GE Lunar software. The images were also analysed by two expert readers using a semi-quantitative approach. Agreement between groups ranged from 95.99% to 98.60%. The intra-rater precision for the application of SpineAnalyzer™ to vertebrae was poor in the upper thoracic regions, but good elsewhere. SpineAnalyzer™ is a reproducible and accurate method for measuring vertebral height and quantifying vertebral fractures from VFA scans. - Highlights: • Vertebral fracture assessment (VFA) using Dual-energy X-ray Absorptiometry (DXA) offers a low-dose opportunity for diagnosis. • Agreement between VFA software (SpineAnalyzer™) and expert readers is high. • Intra-rater precision of SpineAnalyzer™ applied to upper thoracic vertebrae is poor, but good elsewhere. • SpineAnalyzer™ is reproducible and accurate for vertebral height measurement and fracture quantification from VFA scans

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.

The total Hartree-Fock energy-eigenvalue sum relationship in atoms

International Nuclear Information System (INIS)

Sen, K.D.

1979-01-01

Using the well known relationships for the isoelectronic changes in the total Hartree-Fock energy, nucleus-electron attraction energy and electron-electron repulsion energy in atoms a simple polynomial expansion in Z is obtained for the sum of the eigenvalues which can be used to calculate the total Hartree-Fock energy. Numerical results are presented for 2-10 electron series to show that the present relationship is a better approximation than the other available energy-eigenvalue relationships. (author)

Should total hip arthroplasty be performed acutely in the treatment of acetabular fractures in elderly or used as a salvage procedure only?

Directory of Open Access Journals (Sweden)

Katharine Hamlin

2017-01-01

Full Text Available Background: Total hip arthroplasty (THA is now an increasingly common procedure for people sustaining acetabular fractures. The incidence of acetabular fractures among the elderly population is increasing, and contemporary treatment aims to avoid the risks of prolonged incumbency associated with poor bone stock for fixation or inability to comply with limited weightbearing in this patient group. The concept of acute hip arthroplasty as a treatment for acetabular fracture is, therefore, becoming more topical and relevant. Our systematic review investigates whether THAs for acetabular fractures should be performed acutely, with a short delay, or as a late procedure for posttraumatic osteoarthritis (PTOA if it develops. Materials and Methods: Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed when undertaking this systematic review. Detailed searches were performed on three different databases, using keywords, such as “acetabular fracture,” “acetabular trauma,” “total hip arthroplasty,” “hip arthroplasty,” and “hip prosthesis.” Studies from 1975 to September 2016 were included in the study. All studies included in the review were independently critically appraised by two of the authors. Results: Forty three studies were included in this review. Only two of them actually compared acute and delayed THAs for acetabular fractures with the rest focusing on one or the other. Results were comparable between acute and late THAs in terms of aseptic loosening, operative time, blood loss, Harris Hip Score, and ability to mobilize postoperatively without aid. Complication rates, however, were much higher in the acute group. Conclusion: Evidence based on this topic is scarce and therefore we have to be cautious about drawing a definitive conclusion. The findings of this systematic review do suggest, however, that acute THAs should be considered in elderly patients, where fixation is not possible, or

Fracture Characterization in Reactive Fluid-Fractured Rock Systems Using Tracer Transport Data

Science.gov (United States)

Mukhopadhyay, S.

2014-12-01

Fractures, whether natural or engineered, exert significant controls over resource exploitation from contemporary energy sources including enhanced geothermal systems and unconventional oil and gas reserves. Consequently, fracture characterization, i.e., estimating the permeability, connectivity, and spacing of the fractures is of critical importance for determining the viability of any energy recovery program. While some progress has recently been made towards estimating these critical fracture parameters, significant uncertainties still remain. A review of tracer technology, which has a long history in fracture characterization, reveals that uncertainties exist in the estimated parameters not only because of paucity of scale-specific data but also because of knowledge gaps in the interpretation methods, particularly in interpretation of tracer data in reactive fluid-rock systems. We have recently demonstrated that the transient tracer evolution signatures in reactive fluid-rock systems are significantly different from those in non-reactive systems (Mukhopadhyay et al., 2013, 2014). For example, the tracer breakthrough curves in reactive fluid-fractured rock systems are expected to exhibit a long pseudo-state condition, during which tracer concentration does not change by any appreciable amount with passage of time. Such a pseudo-steady state condition is not observed in a non-reactive system. In this paper, we show that the presence of this pseudo-steady state condition in tracer breakthrough patterns in reactive fluid-rock systems can have important connotations for fracture characterization. We show that the time of onset of the pseudo-steady state condition and the value of tracer concentration in the pseudo-state condition can be used to reliably estimate fracture spacing and fracture-matrix interface areas.

Environment - Geothermal, the energy to wake up - Stimulation rather than fracturing - Iceland, the Texas of geothermal energy

International Nuclear Information System (INIS)

Chandes, Camille; Moragues, Manuel

2013-01-01

A first article comments the current efforts for the development of geothermal in France after a period during which it has been given up. It evokes the project of a geothermal plant near Paris (to supply Arcueil and Gentilly with energy), the increasing number of projects in different countries. It outlines the French delay in this sector, and that geothermal energy is as difficult to find as oil. It evokes the new actors of the sector and outlines the fierce competition in front of Icelander, Italian, US and Japanese actors, and the opportunities for the French ones. A second article comments the use of the hydraulic stimulation in geothermal energy exploration rather than hydraulic fracturing as in shale gas exploration, and outlines that according to geothermal energy actors this technique avoids the risk of micro-earthquake. A last article describes the activity of the geothermal sector in Iceland: geothermal energy supplies two thirds of primary energy consumption in this country. It exploits the Icelander volcanism. This development has been particularly noticeable since 2000, but some questions are raised regarding the production potential

Modelling Laccoliths: Fluid-Driven Fracturing in the Lab

Science.gov (United States)

Ball, T. V.; Neufeld, J. A.

2017-12-01

Current modelling of the formation of laccoliths neglects the necessity to fracture rock layers for propagation to occur [1]. In magmatic intrusions at depth the idea of fracture toughness is used to characterise fracturing, however an analogue for near surface intrusions has yet to be explored [2]. We propose an analytical model for laccolith emplacement that accounts for the energy required to fracture at the tip of an intrusion. For realistic physical parameters we find that a lag region exists between the fluid magma front and the crack tip where large negative pressures in the tip cause volatiles to exsolve from the magma. Crucially, the dynamics of this tip region controls the spreading due to the competition between viscous forces and fracture energy. We conduct a series of complementary experiments to investigate fluid-driven fracturing of adhered layers and confirm the existence of two regimes: viscosity dominant spreading, controlled by the pressure in the lag region, and fracture energy dominant spreading, controlled by the energy required to fracture layers. Our experiments provide the first observations, and evolution, of a vapour tip. These experiments and our simplified model provide insight into the key physical processes in near surface magmatic intrusions with applications to fluid-driven fracturing more generally. Michaut J. Geophys. Res. 116(B5), B05205. Bunger & Cruden J. Geophys. Res. 116(B2), B02203.

Energy Inputs Uncertainty: Total Amount, Distribution and Correlation Between Different Forms of Energy

Science.gov (United States)

Deng, Yue

2014-01-01

Describes solar energy inputs contributing to ionospheric and thermospheric weather processes, including total energy amounts, distributions and the correlation between particle precipitation and Poynting flux.

Relation between obesity and bone mineral density and vertebral fractures in Korean postmenopausal women.

Science.gov (United States)

Kim, Kyong-Chol; Shin, Dong-Hyuk; Lee, Sei-Young; Im, Jee-Aee; Lee, Duk-Chul

2010-11-01

The traditional belief that obesity is protective against osteoporosis has been questioned. Recent epidemiologic studies show that body fat itself may be a risk factor for osteoporosis and bone fractures. Accumulating evidence suggests that metabolic syndrome and the individual components of metabolic syndrome such as hypertension, increased triglycerides, and reduced high-density lipoprotein cholesterol are also risk factors for low bone mineral density. Using a cross sectional study design, we evaluated the associations between obesity or metabolic syndrome and bone mineral density (BMD) or vertebral fracture. A total of 907 postmenopausal healthy female subjects, aged 60-79 years, were recruited from woman hospitals in Seoul, South Korea. BMD, vetebral fracture, bone markers, and body composition including body weight, body mass index (BMI), percentage body fat, and waist circumference were measured. After adjusting for age, smoking status, alcohol consumption, total calcium intake, and total energy intake, waist circumference was negatively related to BMD of all sites (lumbar BMD p = 0.037, all sites of femur BMD p related to BMD of all sites (p related to femoral trochanter BMD (p = 0.0366) and was lower in the control group than the fracture group (p = 0.011). In contrast to the effect favorable body weight on bone mineral density, high percentage body fat and waist circumference are related to low BMD and a vertebral fracture. Some components of metabolic syndrome were related to BMD and a vertebral fracture.

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)

Determination of rock fracture parameters from crack models for failure in compression

International Nuclear Information System (INIS)

Kemeny, J.M.; Cook, N.G.W.

1987-01-01

Micromechanical models for axial splitting and for shear faulting are used to investigate parameters associated with rock fracture under compressive stresses. The fracture energies to create splitting fractures and shear faults are calculated using laboratory triaxial data. These energies are compared with the fracture energies for the propagation of microcracks that coalesce to form the larger scale fractures. It is found that for Westerly granite, the energies to create splitting fractures and shear faults are about three orders of magnitude greater than the energy needed to drive the tensile microcracks, due to the large amount of subsidiary crack surface area created in forming the larger scale fractures. A similar scale effect can be expected when extrapolating the laboratory results to field scale problems

Total hip arthroplasty for femoral neck fractures as an urgent procedure

Directory of Open Access Journals (Sweden)

Radoičić Dragan

2017-01-01

Full Text Available Background/Aim. Total hip arthroplasty (THA is one of the most widely accepted operative methods for femoral neck fracture (FNF in elderly. However, the data on the early THA for FNF are very limited. The aim of this study to determine if there were differences in postoperative complications and functional outcomes between an urgent and delayed THA following FNF. Methods. This prospective study included a total of 244 patients who had THA following FNF from January 2010 to January 2013. In the first group 41 FNF patients were treated with THA within less than 12 hours of admission. A total of 203 FNF patients were operated in delayed settings, of whom 162 required prolonged preoperative processing and comorbidities correction. The group II consisted of 41 FNF patients who were fit for the early surgery at admission, but the operation was delayed due to institution related reasons. Main outcome measurements included mortality, functional outcome assessement, cardiological and pulmonary complications, pressure ulcers, dislocations, infections, length of hospitalization and revisions. Results. There were no differences in terms of age, gender, type of implants, neither in mortality, nor complications. There were differences in hospital length of stay [t (51.72 = -10.25, p < 0.001]. The patients operated within less than 12 hours of admission, had significantly better scores at all three time points of functional outcome assessment: at discharge t (80 = 2.556, p < 0.012; one month t (80 = 4.731, p < 0.001; three months t (80 = 5.908, p < 0.001. Conclusion. THA for FNF as an urgent procedure is not a widely accepted concept. Our findings indicate that the early operative treatment, does not worsen clinical outcomes, and our results give an advantage to the policy of the early THA for FNF.

Paediatric talus fracture.

LENUS (Irish Health Repository)

Byrne, Ann-Maria

2012-01-01

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

Combining total energy and energy industrial center concepts to increase utilization efficiency of geothermal energy

Science.gov (United States)

Bayliss, B. P.

1974-01-01

Integrating energy production and energy consumption to produce a total energy system within an energy industrial center which would result in more power production from a given energy source and less pollution of the environment is discussed. Strong governmental support would be required for the crash drilling program necessary to implement these concepts. Cooperation among the federal agencies, power producers, and private industry would be essential in avoiding redundant and fruitless projects, and in exploiting most efficiently our geothermal resources.

Medium properties and total energy coupling in underground explosions

International Nuclear Information System (INIS)

Kurtz, S.R.

1975-01-01

A phenomenological model is presented that allows the direct calculation of the effects of variations in medium properties on the total energy coupling between the medium and an underground explosion. The model presented is based upon the assumption that the shock wave generated in the medium can be described as a spherical blast wave at early times. The total energy coupled to the medium is then simply the sum of the kinetic and internal energies of this blast wave. Results obtained by use of this model indicate that the energy coupling is more strongly affected by the medium's porosity than by its water content. These results agree well with those obtained by summing the energy deposited by the blast wave as a function of range

Bone mineral density and bone markers in patients with a recent low-energy fracture: effect of 1 y of treatment with calcium and vitamin D

DEFF Research Database (Denmark)

Hitz, Mette F; Jensen, Jens-Erik B; Eskildsen, Peter C

2007-01-01

BACKGROUND: Low-energy fractures of the hip, forearm, shoulder, and spine are known consequences of osteoporosis. OBJECTIVE: We evaluated the effect of 1 y of treatment with calcium and vitamin D on bone mineral density (BMD) and bone markers in patients with a recent low-energy fracture. DESIGN...

Near Wellbore Hydraulic Fracture Propagation from Perforations in Tight Rocks: The Roles of Fracturing Fluid Viscosity and Injection Rate

Directory of Open Access Journals (Sweden)

Seyed Hassan Fallahzadeh

2017-03-01

Full Text Available Hydraulic fracture initiation and near wellbore propagation is governed by complex failure mechanisms, especially in cased perforated wellbores. Various parameters affect such mechanisms, including fracturing fluid viscosity and injection rate. In this study, three different fracturing fluids with viscosities ranging from 20 to 600 Pa.s were used to investigate the effects of varying fracturing fluid viscosities and fluid injection rates on the fracturing mechanisms. Hydraulic fracturing tests were conducted in cased perforated boreholes made in tight 150 mm synthetic cubic samples. A true tri-axial stress cell was used to simulate real far field stress conditions. In addition, dimensional analyses were performed to correspond the results of lab experiments to field-scale operations. The results indicated that by increasing the fracturing fluid viscosity and injection rate, the fracturing energy increased, and consequently, higher fracturing pressures were observed. However, when the fracturing energy was transferred to a borehole at a faster rate, the fracture initiation angle also increased. This resulted in more curved fracture planes. Accordingly, a new parameter, called fracturing power, was introduced to relate fracture geometry to fluid viscosity and injection rate. Furthermore, it was observed that the presence of casing in the wellbore impacted the stress distribution around the casing in such a way that the fracture propagation deviated from the wellbore vicinity.

Anisotropic composite human skull model and skull fracture validation against temporo-parietal skull fracture.

Science.gov (United States)

Sahoo, Debasis; Deck, Caroline; Yoganandan, Narayan; Willinger, Rémy

2013-12-01

A composite material model for skull, taking into account damage is implemented in the Strasbourg University finite element head model (SUFEHM) in order to enhance the existing skull mechanical constitutive law. The skull behavior is validated in terms of fracture patterns and contact forces by reconstructing 15 experimental cases. The new SUFEHM skull model is capable of reproducing skull fracture precisely. The composite skull model is validated not only for maximum forces, but also for lateral impact against actual force time curves from PMHS for the first time. Skull strain energy is found to be a pertinent parameter to predict the skull fracture and based on statistical (binary logistical regression) analysis it is observed that 50% risk of skull fracture occurred at skull strain energy of 544.0mJ. © 2013 Elsevier Ltd. All rights reserved.

Treatment of segmental tibial fractures with supercutaneous plating.

Science.gov (United States)

He, Xianfeng; Zhang, Jingwei; Li, Ming; Yu, Yihui; Zhu, Limei

2014-08-01

Segmental tibial fractures usually follow a high-energy trauma and are often associated with many complications. The purpose of this report is to describe the authors' results in the treatment of segmental tibial fractures with supercutaneous locking plates used as external fixators. Between January 2009 and March 2012, a total of 20 patients underwent external plating (supercutaneous plating) of the segmental tibial fractures using a less-invasive stabilization system locking plate (Synthes, Paoli, Pennsylvania). Six fractures were closed and 14 were open (6 grade IIIa, 2 grade IIIb, 4 grade II, and 2 grade I, according to the Gustilo classification). When imaging studies confirmed bone union, the plates and screws were removed in the outpatient clinic. Average time of follow-up was 23 months (range, 12-47 months). All fractures achieved union. Median time to union was 19 weeks (range, 12-40 weeks) for the proximal fractures and 22 weeks (range, 12-42 weeks) for the distal fractures. Functional results were excellent in 17 patients and good in 3. Delayed union of the fracture occurred in 2 patients. All patients' radiographs showed normal alignment. No rotational deformities and leg shortening were seen. No incidences of deep infection or implant failures occurred. Minor screw tract infection occurred in 2 patients. A new 1-stage protocol using supercutaneous plating as a definitive fixator for segmental tibial fractures is less invasive, has a lower cost, and has a shorter hospitalization time. Surgeons can achieve good reduction, soft tissue reconstruction, stable fixation, and high union rates using supercutaneous plating. The current patients obtained excellent knee and ankle joint motion and good functional outcomes and had a comfortable clinical course. Copyright 2014, SLACK Incorporated.

An updated fracture-flow model for total-system performance assessment of Yucca Mountain

International Nuclear Information System (INIS)

Gauthier, J.H.

1994-01-01

Improvements have been made to the fracture-flow model being used in the total-system performance assessment of a potential high-level radioactive waste repository at Yucca Mountain, Nevada. The open-quotes weeps modelclose quotes now includes (1) weeps of varied sizes, (2) flow-pattern fluctuations caused by climate change, and (3) flow-pattern perturbations caused by repository heat generation. Comparison with the original weeps model indicates that allowing weeps of varied sizes substantially reduces the number of weeps and the number of containers contacted by weeps. However, flow-pattern perturbations caused by either climate change or repository heat generation greatly increases the number of containers contacted by weeps. In preliminary total-system calculations, using a phenomenological container-failure and radionuclide-release model, the weeps model predicts that radionuclide releases from a high-level radioactive waste repository at Yucca Mountain will be below the EPA standard specified in 40 CFR 191, but that the maximum radiation dose to an individual could be significant. Specific data from the site are required to determine the validity of the weep-flow mechanism and to better determine the parameters to which the dose calculation is sensitive

An updated fracture-flow model for total-system performance assessment of Yucca Mountain

International Nuclear Information System (INIS)

Gauthier, J.H.

1994-01-01

Improvements have been made to the fracture-flow model being used in the total-system performance assessment of a potential high-level radioactive waste repository at Yucca Mountain, Nevada. The ''weeps model'' now includes (1) weeps of varied sizes, (2) flow-pattern fluctuations caused by climate change, and (3) flow-pattern perturbations caused by repository heat generation. Comparison with the original weeps model indicates that allowing weeps of varied sizes substantially reduces the number of weeps and the number of containers contacted by weeps. However, flow-pattern perturbations caused by either climate change or repository heat generation greatly increases the number of containers contacted by weeps. In preliminary total-system calculations, using a phenomenological container-failure and radionuclide-release model, the weeps model predicts that radionuclide releases from a high-level radioactive waste repository at Yucca Mountain will be below the EPA standard specified in 40 CFR 191, but that the maximum radiation dose to an individual could be significant. Specific data from the site are required to determine the validity of the weep-flow mechanism and to better determine the parameters to which the dose calculation is sensitive

The Frank Stinchfield Award : Total Hip Arthroplasty for Femoral Neck Fracture Is Not a Typical DRG 470: A Propensity-matched Cohort Study.

Science.gov (United States)

Schairer, William W; Lane, Joseph M; Halsey, David A; Iorio, Richard; Padgett, Douglas E; McLawhorn, Alexander S

2017-02-01

Hip fractures are a major public health concern. For displaced femoral neck fractures, the needs for medical services during hospitalization and extending beyond hospital discharge after total hip arthroplasty (THA) may be different than the needs after THA performed for osteoarthritis (OA), yet these differences are largely uncharacterized, and the Medicare Severity Diagnosis-Related Groups system does not distinguish between THA performed for fracture and OA. (1) What are the differences in in-hospital and 30-day postoperative clinical outcomes for THA performed for femoral neck fracture versus OA? (2) Is a patient's fracture status, that is whether or not a patient has a femoral neck fracture, associated with differences in in-hospital and 30-day postoperative clinical outcomes after THA? The National Surgical Quality Improvement Program (NSQIP) database, which contains outcomes for surgical patients up to 30 days after discharge, was used to identify patients undergoing THA for OA and femoral neck fracture. OA and fracture cohorts were matched one-to-one using propensity scores based on age, gender, American Society of Anesthesiologists grade, and medical comorbidities. Propensity scores represented the conditional probabilities for each patient having a femoral neck fracture based on their individual characteristics, excluding their actual fracture status. Outcomes of interest included operative time, length of stay (LOS), complications, transfusion, discharge destination, and readmission. There were 42,692 patients identified (41,739 OA; 953 femoral neck fractures) with 953 patients in each group for the matched analysis. For patients with fracture, operative times were slightly longer (98 versus 92 minutes, p = 0.015), they experienced longer LOS (6 versus 4 days, p group (2.0% versus 0.2%, p = 0.002), the frequency of postoperative transfusion was not different between groups (27% versus 24%, p = 0.157). Having a femoral neck fracture versus OA was

Detection of occult, undisplaced hip fractures with a dual-energy CT algorithm targeted to detection of bone marrow edema.

Science.gov (United States)

Reddy, T; McLaughlin, P D; Mallinson, P I; Reagan, A C; Munk, P L; Nicolaou, S; Ouellette, H A

2015-02-01

The purpose of this study is to describe our initial clinical experience with dual-energy computed tomography (DECT) virtual non-calcium (VNC) images for the detection of bone marrow (BM) edema in patients with suspected hip fracture following trauma. Twenty-five patients presented to the emergency department at a level 1 trauma center between January 1, 2011 and January 1, 2013 with clinical suspicion of hip fracture and normal radiographs were included. All CT scans were performed on a dual-source, dual-energy CT system. VNC images were generated using prototype software and were compared to regular bone reconstructions by two musculoskeletal radiologists in consensus. Radiological and/or clinical diagnosis of fracture at 30-day follow-up was used as the reference standard. Twenty-one patients were found to have DECT-VNC signs of bone marrow edema. Eighteen of these 21 patients were true positive and three were false positive. A concordant fracture was clearly seen on bone reconstruction images in 15 of the 18 true positive cases. In three cases, DECT-VNC was positive for bone marrow edema where bone reconstruction CT images were negative. Four patients demonstrated no DECT-VNC signs of bone marrow edema: two cases were true negative, two cases were false negative. When compared with the gold standard of hip fracture determined at retrospective follow-up, the sensitivity of DECT-VNC images of the hip was 90 %, specificity was 40 %, positive predictive value was 86 %, and negative predictive value was 50 %. Our initial experience would suggest that DECT-VNC is highly sensitive but poorly specific in the diagnosis of hip fractures in patients with normal radiographs. The value of DECT-VNC primarily lies in its ability to help detect fractures which may be subtle or undetectable on bone reconstruction CT images.

A variational approach to fracture and other inelastic phenomena

CERN Document Server

Piero, Gianpietro

2014-01-01

This book exposes a number of mathematical models for fracture of growing difficulty. All models are treated in a unified way, based on incremental energy minimization. They differ from each other by the assumptions made on the inelastic part of the total energy, here called the "cohesive energy". Each model describes a specific aspect of material response, and particular care is devoted to underline the correspondence of each model to the experiments.  The content of the book is  a re-elaboration of the lectures delivered at the First Sperlonga Summer School on Mechanics and Engineering Sciences in September 2011. In the year and a half elapsed after the course, the material has been revised and enriched with new and partially unpublished results. Significant additions have been introduced in the occasion of the course "The variational approach to fracture and other inelastic phenomena", delivered at SISSA, Trieste, in March 2013.  The Notes reflect a research line carried on by the writer over the yea...

Innovations in the management of hip fractures.

Science.gov (United States)

Teasdall, Robert D; Webb, Lawrence X

2003-08-01

Hip fractures 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 that is exposed to large compressive stresses. Implants used to address these fractures must accommodate significant loads while the fractures consolidate. Complications secondary to hip fractures produce significant morbidity and include infection, nonunion, malunion, decubitus ulcers, fat emboli, deep venous thrombosis, pulmonary embolus, pneumonia, myocardial infarction, stroke, and death.

Early age fracture properties of microstructurally-designed mortars

DEFF Research Database (Denmark)

Di Bella, Carmelo; Michel, Alexander; Stang, Henrik

2017-01-01

This paper compares the fracture properties as well as crack initiation and propagation of real and equivalent mortars. The development of the elastic modulus, tensile strength, and fracture energy at different hydration stages were determined by inverse analysis of load-displacement curves...... the two mortars. At early age, the moisture content has a considerable influence on the tensile strength and the fracture energy....

Arthroplasty for Unreconstructable Acute Fractures and Failed Fracture Fixation About the Hip and Knee in the Active Elderly: A New Paradigm.

Science.gov (United States)

Kyle, Richard F; Duwelius, Paul J; Haidukewych, George J; Schmidt, Andrew H

2017-02-15

The techniques, materials, and designs for total joint arthroplasty underwent major improvements in the past 30 years. During this time, trauma surgeons classified the severity of fractures as well as identified certain articular fractures that do not have good outcomes and have a high rate of failure after internal fixation. Advanced improvements in arthroplasty have increased its reliability and longevity. Total joint arthroplasty is becoming a standard of care for some acute articular fractures, particularly displaced femoral neck fractures in the active elderly. Total joint arthroplasty also has become the standard of care after failed internal fixation in patients who have very complicated fractures about the knee, hip, and shoulder. As the population ages, fractures worldwide continue to rapidly increase. Elderly patients have a high risk for fractures that result from falls because of their poor bone quality. The current active elderly population participates in higher risk activities than previous elderly populations, which places them at risk for more injuries. This has become both a worldwide healthcare problem and an economic problem. Surgeons need to manage fractures in the active elderly with the latest advancements in technology and patient selection to ensure rapid recovery and the reduction of complications.

HEALING OF ARTICULAR AND PERIARTICULAR METACARPAL AND PHALANGEAL FRACTURES

Directory of Open Access Journals (Sweden)

Aleksandar Kruščić

2003-12-01

ligamentotaxis were without significant slides, the fragments healing in good position. End functional results were satisfactory. We had only one decubitus, which healed per primam after reshaping of the splint.Conclusions. The application of local analgesia and ligamentotaxis represents a simple and safe method of treatment. It allows individual biomechanical neutralization of the pathologic activity of kinetic energy vectors on the fracture. Repositioning and physiological positioning of the hand in Softcast plaster is simple, there is no need to hospitalize the patient for surgery. This makes the method less costly as well. There are less fracture slides, and repairs due to decubitus are simpler as there is no need for total immobilization removal. Therefore ligamentotaxis is the method of choice.

[Review of wireless energy transmission system for total artificial heart].

Science.gov (United States)

Zhang, Chi; Yang, Ming

2009-11-01

This paper sums up the fundamental structure of wireless energy transmission system for total artificial heart, and compares the key parameters and performance of some representative systems. After that, it is discussed that the future development trend of wireless energy transmission system for total artificial heart.

In adolescence a higher 'eveningness in energy intake' is associated with higher total daily energy intake.

Science.gov (United States)

Diederichs, Tanja; Perrar, Ines; Roßbach, Sarah; Alexy, Ute; Buyken, Anette E

2018-05-26

The present manuscript addressed two hypotheses: (i) As children age, energy intake is shifted from morning (energy intake energy intake >6pm) (ii) A higher 'eveningness in energy intake' (i.e. evening minus morning energy intake) is associated with a higher total daily energy intake. Data were analyzed from 262 DONALD cohort study participants, who had completed at least one 3-day weighed dietary record in the age groups 3/4, 5/6, 7/8, 9/10, 11/12, 13/14, 15/16 and 17/18 years (y). 'Eveningness in energy intake' was compared across age groups and related to total daily energy intake for each age group (multiple cross-sectional analyses). 'Eveningness' increased progressively from age group 3/4y to age group 17/18y. A median surplus of evening energy intake (i.e. when evening intake exceeded morning intake) was firstly observed for age group 11/12y. From age group 11/12y onwards, a higher 'eveningness' was associated with a higher total daily energy intake (all p energy intake between the highest and the lowest tertile of 'eveningness' was largest for age group 17/18y, amounting to an 11% higher intake among adolescents in the highest as compared to those in the lowest tertile. In conclusion, energy intake progressively shifts from morning to evening hours as children age. Once evening energy intake exceeds morning energy intake, a higher 'eveningness in energy intake' is associated with higher total daily energy intake. Copyright © 2018 Elsevier Ltd. All rights reserved.

Rio Blanco massive hydraulic fracture: project definition

International Nuclear Information System (INIS)

1976-01-01

A recent Federal Power Commission feasibility study assessed the possibility of economically producing gas from three Rocky Mountain basins. These basins have potentially productive horizons 2,000 to 4,000 feet thick containing an estimated total of 600 trillion cubic feet of gas in place. However, the producing sands are of such low permeability and heterogeneity that conventional methods have failed to develop these basins economically. The Natural Gas Technology Task Force, responsible for preparing the referenced feasibility study, determined that, if effective well stimulation methods for these basins can be developed, it might be possible to recover 40 to 50 percent of the gas in place. The Task Force pointed out two possible underground fracturing methods: Nuclear explosive fracturing, and massive hydraulic fracturing. They argued that once technical viability has been demonstrated, and with adequate economic incentives, there should be no reason why one or even both of these approaches could not be employed, thus making a major contribution toward correcting the energy deficiency of the Nation. A joint Government-industry demonstration program has been proposed to test the relative effectiveness of massive hydraulic fracturing of the same formation and producing horizons that were stimulated by the Rio Blanco nuclear project

Total Cross Sections at High Energies An update

CERN Document Server

Fazal-e-Aleem, M; Alam, Saeed; Qadee-Afzal, M

2002-01-01

Current and Future measurements for the total cross sections at E-811, PP2PP, CSM, FELIX and TOTEM have been analyzed using various models. In the light of this study an attempt has been made to focus on the behavior of total cross section at very high energies.

Vertebral fractures assessed with dual-energy X-ray absorptiometry in patients with Addison's disease on glucocorticoid and mineralocorticoid replacement therapy.

Science.gov (United States)

Camozzi, Valentina; Betterle, Corrado; Frigo, Anna Chiara; Zaccariotto, Veronica; Zaninotto, Martina; De Caneva, Erica; Lucato, Paola; Gomiero, Walter; Garelli, Silvia; Sabbadin, Chiara; Salvà, Monica; Costa, Miriam Dalla; Boscaro, Marco; Luisetto, Giovanni

2018-02-01

to assess bone damage and metabolic abnormalities in patients with Addison's disease given replacement doses of glucocorticoids and mineralocorticoids. A total of 87 patients and 81 age-matched and sex-matched healthy controls were studied. The following parameters were measured: urinary cortisol, serum calcium, phosphorus, creatinine, 24-h urinary calcium excretion, bone alkaline phosphatase, parathyroid hormone, serum CrossLaps, 25 hydroxyvitamin D, and 1,25 dihydroxyvitamin D. Clear vertebral images were obtained with dual-energy X-ray absorptiometry in 61 Addison's disease patients and 47 controls and assessed using Genant's classification. Nineteen Addison's disease patients (31.1%) had at least one morphometric vertebral fracture, as opposed to six controls (12.8%, odds ratio 3.09, 95% confidence interval 1.12-8.52). There were no significant differences in bone mineral density parameters at any site between patients and controls. In Addison's disease patients, there was a positive correlation between urinary cortisol and urinary calcium excretion. Patients with fractures had a longer history of disease than those without fractures. Patients taking fludrocortisone had a higher bone mineral density than untreated patients at all sites except the lumbar spine. Addison's disease patients have more fragile bones irrespective of any decrease in bone mineral density. Supra-physiological doses of glucocorticoids and longer-standing disease (with a consequently higher glucocorticoid intake) might be the main causes behind patients' increased bone fragility. Associated mineralocorticoid treatment seems to have a protective effect on bone mineral density.

Institutional total energy case studies

Energy Technology Data Exchange (ETDEWEB)

Wulfinghoff, D.

1979-07-01

Profiles of three total energy systems in institutional settings are provided in this report. The plants are those of Franciscan Hospital, a 384-bed facility in Rock Island, Illinois; Franklin Foundation Hospital, a 100-bed hospital in Franklin, Louisiana; and the North American Air Defense Command Cheyenne Mountain Complex, a military installation near Colorado Springs, Colorado. The case studies include descriptions of plant components and configurations, operation and maintenance procedures, reliability, relationships to public utilities, staffing, economic efficiency, and factors contributing to success.

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

Comparative risk assessment of total energy systems

International Nuclear Information System (INIS)

Soerensen, B.

1982-01-01

The paper discusses a methodology for total impact assessment of energy systems, ideally evaluating all the impacts that a given energy system has on the society in which it is imbedded or into which its introduction is being considered. Impacts from the entire energy conversion chain ('fuel cycle' if the system is fuel-based), including energy storage, transport and transmission, as well as the institutions formed in order to manage the system, should be compared on the basis of the energy service provided. A number of impacts are considered, broadly classified as impacts on satisfaction of biological needs, on health, on environment, on social relations and on the structure of society. Further considerations include impacts related to cost and resilience, and, last but not least, impacts on global relations. The paper discusses a number of published energy studies in the light of the comparative impact assessment methodology outlined above. (author)

Dependence of mechanical characteristics from composition and structure and optimization of mechanical fracture energy of polymer composite material based on high-molecular rubbers

Directory of Open Access Journals (Sweden)

E. Nurullaev

2017-07-01

Full Text Available By means of numerical experiment the authors investigate dependence of conventional rupturing stress and mechanical fracture energy at uniaxial tension from fractional composition of dispersed filler, plasticizer volume fraction in polymer binder, effective density of transverse bonds, applied to development of covering for different purposes and with advanced service life in temperature range from 223 to 323 K. They compare mechanical characteristics of polymer composite materials (PCMs based on high- and low-molecular rubbers. It was shown that rupturing stress of high-molecular rubber-based PCM is of a higher magnitude than the stress of low-molecular rubber-based one at almost invariable rupturing deformation. Numerical simulation by variation of composition parameters and molecular structure enables evaluation of its maximum fracture energy which is 1000 times higher than mechanical fracture energy of similar composites based on low-molecular rubbers.

A constrained optimization algorithm for total energy minimization in electronic structure calculations

International Nuclear Information System (INIS)

Yang Chao; Meza, Juan C.; Wang Linwang

2006-01-01

A new direct constrained optimization algorithm for minimizing the Kohn-Sham (KS) total energy functional is presented in this paper. The key ingredients of this algorithm involve projecting the total energy functional into a sequence of subspaces of small dimensions and seeking the minimizer of total energy functional within each subspace. The minimizer of a subspace energy functional not only provides a search direction along which the KS total energy functional decreases but also gives an optimal 'step-length' to move along this search direction. Numerical examples are provided to demonstrate that this new direct constrained optimization algorithm can be more efficient than the self-consistent field (SCF) iteration

Minimizing the Fluid Used to Induce Fracturing

Science.gov (United States)

Boyle, E. J.

2015-12-01

The less fluid injected to induce fracturing means less fluid needing to be produced before gas is produced. One method is to inject as fast as possible until the desired fracture length is obtained. Presented is an alternative injection strategy derived by applying optimal system control theory to the macroscopic mass balance. The picture is that the fracture is constant in aperture, fluid is injected at a controlled rate at the near end, and the fracture unzips at the far end until the desired length is obtained. The velocity of the fluid is governed by Darcy's law with larger permeability for flow along the fracture length. Fracture growth is monitored through micro-seismicity. Since the fluid is assumed to be incompressible, the rate at which fluid is injected is balanced by rate of fracture growth and rate of loss to bounding rock. Minimizing injected fluid loss to the bounding rock is the same as minimizing total injected fluid How to change the injection rate so as to minimize the total injected fluid is a problem in optimal control. For a given total length, the variation of the injected rate is determined by variations in overall time needed to obtain the desired fracture length, the length at any time, and the rate at which the fracture is growing at that time. Optimal control theory leads to a boundary condition and an ordinary differential equation in time whose solution is an injection protocol that minimizes the fluid used under the stated assumptions. That method is to monitor the rate at which the square of the fracture length is growing and adjust the injection rate proportionately.

Prosthetic replacement for proximal humeral fractures.

Science.gov (United States)

Kontakis, George; Tosounidis, Theodoros; Galanakis, Ioannis; Megas, Panagiotis

2008-12-01

The ideal management of complex proximal humeral fractures continues to be debatable. Evolution of proximal humeral fracture management, during the past decade, led to the implementation of many innovations in surgical treatment. Even though the pendulum of treatment seems to swing towards new trends such as locked plating, hemiarthroplasty remains a valid and reliable option that serves the patient's needs well. Hemiarthroplasty is indicated for complex proximal humeral fractures in elderly patients with poor bone stock and when internal fixation is difficult or unreliable. Hemiarthroplasty provides a better result when it is performed early post-injury. Stem height, retroversion and tuberosity positioning are technical aspects of utmost importance. Additionally reverse total shoulder arthroplasty is an alternative new modality that can be used as a primary solution in selected patients with proximal humeral fracture treatment. Failed hemiarthroplasty and fracture sequelae can be successfully managed with reverse total shoulder arthroplasty. Individual decision-making and tailored treatment that takes into consideration the personality of the fracture and the patient's characteristics should be used.

Fracture toughness of esthetic dental coating systems by nanoindentation and FIB sectional analysis.

Science.gov (United States)

Pecnik, Christina Martina; Courty, Diana; Muff, Daniel; Spolenak, Ralph

2015-07-01

Improving the esthetics of Ti-based dental implants is the last challenge remaining in the optimization process. The optical issues were recently solved by the application of highly and selectively reflective coatings on Ti implants. This work focuses on the mechanical durability of these esthetic ceramic based coating systems (with and without adhesion layers). The coating systems (Ti-ZrO2, Ti-Al-ZrO2, Ti-Ti-Al-ZrO2, Ti-Ag-ZrO2, Ti-Ti-Ag-ZrO2, Ti-Bragg and Ti-TiO2-Bragg) were subjected to nanoindentation experiments and examined using scanning electron microscopy and focused ion beam cross sectional analysis. Three coating systems contained adhesion layers (10nm of Ti or 60nm of TiO2 layers). The fracture toughness of selected samples was assessed applying two different models from literature, a classical for bulk materials and an energy-based model, which was further developed and adjusted. The ZrO2 based coating systems (total film thickness<200nm) followed a circumferential cracking behavior in contrast to Bragg coated samples (total film thickness around 1.5μm), which showed radial cracking emanating from the indent corners. For Ti-ZrO2 samples, a fracture toughness between 2.70 and 3.70MPam(1/2) was calculated using an energy-based model. The classical model was applied to Bragg coated samples and their fracture toughness ranged between 0.70 and 0.80MPam(1/2). Furthermore, coating systems containing an additional layer (Ti-Ti-Al-ZrO2, Ti-Ti-Ag-ZrO2 and Ti-TiO2-Bragg) showed an improved adhesion between the substrate and the coating. The addition of a Ti or TiO2 layer improved the adhesion between substrate and coating. The validity of the models for the assessment of the fracture toughness depended on the layer structure and fracture profile of the samples investigated here (classical model for thick coatings and energy-based model for thin coatings). Copyright © 2015 Elsevier Ltd. All rights reserved.

Clavicular fractures: Classification, diagnosis, therapy

International Nuclear Information System (INIS)

Schunk, K.; Strunk, H.; Schild, H.; Lohr, S.

1988-01-01

Clavicular fracture is one of the most frequent skeletal lesions. In most cases the median third of the clavicula is affected (this is due to the peculiar biomechanical structure). Accompanying lesions and complications of clavicular fractures are rare. A total of 13 X-ray diagnostic techniques are described of clavicular fractures. X-ray film should, as a matter of principle, always be taken in two planes. Definitely the major part of clavicular fractures are treated conservatively (rucsac dressing), whereas surgery is reserved for few and strictly defined indications. (orig.) [de

Clavicular fractures: Classification, diagnosis, therapy

Energy Technology Data Exchange (ETDEWEB)

Schunk, K.; Strunk, H.; Schild, H.; Lohr, S.

1988-09-01

Clavicular fracture is one of the most frequent skeletal lesions. In most cases the median third of the clavicula is affected (this is due to the peculiar biomechanical structure). Accompanying lesions and complications of clavicular fractures are rare. A total of 13 X-ray diagnostic techniques are described of clavicular fractures. X-ray film should, as a matter of principle, always be taken in two planes. Definitely the major part of clavicular fractures are treated conservatively (rucsac dressing), whereas surgery is reserved for few and strictly defined indications.

Stress, Flow and Particle Transport in Rock Fractures

Energy Technology Data Exchange (ETDEWEB)

Koyama, Tomofumi

2007-09-15

by the coupled shear-flow tests of fracture specimens with visualization of the fluid flow. From the obtained flow velocity fields, the particle transport was predicted by the streamline particle tracking method with calculated flow velocity fields (vectors) from the flow simulations, obtaining results such as flow velocity profiles, total flow rates, particle travel time, breakthrough curves and the Peclet number, Pe, respectively. The fluid flow in the vertical 2-D cross-sections of a rock fracture was also simulated by solving both Navier-Stokes (NS) and Reynolds equations, and the particle transport was predicted by streamline particle tracking method. The results obtained using NS and Reynolds equations were compared to illustrate the degree of the validity of the Reynolds equation for general applications in practice since the later is mush more computationally efficient for large scale problems. The flow simulation results show that the total flow rate and the flow velocity predicted by NS equations are quite different from that as predicted by the Reynolds equation. The results show that a roughly 5-10 % overestimation on the flow rate is produced when the Reynolds equation is used, and the ideal parabolic velocity profiles defined by the local cubic law, when Reynolds equation is used, is no longer valid, especially when the roughness feature of the fracture surfaces changes with shear. These deviations of flow rate and flow velocity profiles across the fracture aperture have a significant impact on the particle transport behavior and the associated properties, such as the travel time and Peclet number. The deviations increase with increasing flow velocity and become more significant when fracture aperture geometry changes with shear. The scientific findings from these studies provided new insights to the physical behavior of fluid flow and mass transport in rock fractures which is the scientific basis for many rock mechanics problems at the fundamental

Tensile and fracture behavior of polymer foams

International Nuclear Information System (INIS)

Kabir, Md. E.; Saha, M.C.; Jeelani, S.

2006-01-01

Tensile and mode-I fracture behavior of cross-linked polyvinyl chloride (PVC) and rigid polyurethane (PUR) foams are examined. Tension tests are performed using prismatic bar specimens and mode-I fracture tests are performed using single edge notched bend (SENB) specimens under three-point bending. Test specimens are prepared from PVC foams with three densities and two different levels of cross-linking, and PUR foam with one density. Tension and quasi-static fracture tests are performed using a Zwick/Rowell test machine. Dynamic fracture tests are performed using a DYNATUP model 8210 instrumented drop-tower test set up at three different impact energy levels. Various parameters such as specimen size, loading rate, foam density, cross-linking, crack length, cell orientation (flow and rise-direction) and solid polymer material are studied. It is found that foam density and solid polymer material have a significant effect on tensile strength, modulus, and fracture toughness of polymer foams. Level of polymer cross-linking is also found to have a significant effect on fracture toughness. The presence of cracks in the rise- and flow direction as well as loading rate has minimal effect. Dynamic fracture behavior is found to be different as compared to quasi-static fracture behavior. Dynamic fracture toughness (K d ) increases with impact energy. Examination of fracture surfaces reveals that the fracture occurs in fairly brittle manner for all foam materials

A comparison of bone mineral density in osteoporotic fracture of the proximal femur using dual energy X-ray absorptiometry

International Nuclear Information System (INIS)

Lee, Jong Seok; Yoo, Beong Gyu; Kim, Keung Sik

2000-01-01

There were some controversies about direct cause of hip fracture. We attempted to look at 40 osteoporotic proximal femur fractures in women over 50 years between March in 1999 and February in 2000. The bone density of the fracture group and the healthy 85 control group was measured by Dual Energy X-ray absorptiometry (DEXA). The result was compared using age matched paired T test. The results were as follows: The femoral neck fractures were 14 cases and the trochanteric fractures were 26 cases. Mean age at a fracture was 67.1 years in neck fracture group and 76.5 years in trochanteric fracture. In the control group, the bone density of both side of the proximal femur was measured and it showed statistically no difference between both sides in same person. The bone density of neck, Ward's triangle, trochanter (P<0.05) and lumbar spine (P<0.001) was significantly reduced in the proximal femoral fracture group comparing with the control group. The bone density of neck, Ward's triangle, trochanter (P<0.05) was significantly reduced in the proximal femoral neck fracture group comparing with the control group, but there was no statistical difference in lumbar spine comparing with the control group. The bone density of neck, Ward's triangle, trochanter and lumbar spine (P<0.001) was significantly reduced in the proximal femoral neck fracture group comparing with the control group. We concluded that the bone mineral densities (BMD) of proximal femur and lumbar spine had decreased in hip fractures but that the bone mineral density and T-score % of the proximal femur were statistically lower than that of the lumbar spine. We suggest that measuring the bone mineral density of the proximal femur may reflect the weakness of the proximal femur more precisely than measuring the bone mineral density of the lumbar spine

A comparison of bone mineral density in osteoporotic fracture of the proximal femur using dual energy X-ray absorptiometry

Energy Technology Data Exchange (ETDEWEB)

Lee, Jong Seok; Yoo, Beong Gyu [Wonkwang Health Science College, Iksan (Korea, Republic of); Kim, Keung Sik [Yonsei University Yong Dong Severance Hospital, Seoul (Korea, Republic of)

2000-04-15

There were some controversies about direct cause of hip fracture. We attempted to look at 40 osteoporotic proximal femur fractures in women over 50 years between March in 1999 and February in 2000. The bone density of the fracture group and the healthy 85 control group was measured by Dual Energy X-ray absorptiometry (DEXA). The result was compared using age matched paired T test. The results were as follows: The femoral neck fractures were 14 cases and the trochanteric fractures were 26 cases. Mean age at a fracture was 67.1 years in neck fracture group and 76.5 years in trochanteric fracture. In the control group, the bone density of both side of the proximal femur was measured and it showed statistically no difference between both sides in same person. The bone density of neck, Ward's triangle, trochanter (P<0.05) and lumbar spine (P<0.001) was significantly reduced in the proximal femoral fracture group comparing with the control group. The bone density of neck, Ward's triangle, trochanter (P<0.05) was significantly reduced in the proximal femoral neck fracture group comparing with the control group, but there was no statistical difference in lumbar spine comparing with the control group. The bone density of neck, Ward's triangle, trochanter and lumbar spine (P<0.001) was significantly reduced in the proximal femoral neck fracture group comparing with the control group. We concluded that the bone mineral densities (BMD) of proximal femur and lumbar spine had decreased in hip fractures but that the bone mineral density and T-score % of the proximal femur were statistically lower than that of the lumbar spine. We suggest that measuring the bone mineral density of the proximal femur may reflect the weakness of the proximal femur more precisely than measuring the bone mineral density of the lumbar spine.

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.

Interface waves propagating along tensile fractures in dolomite

International Nuclear Information System (INIS)

Roy, S.; Pyrak-Nolte, L.J.

1995-01-01

Elastic interface waves have been observed in induced tensile fractures in dolomite rock cores. Multiscaling wavelet analysis distinguishes the interface wave from bulk shear waves, quantifies the interface wave spectral content, and determines the arrival time of peak energy. The dominant seismic energy is concentrated in the slow interface wave, with little or no detectable energy in the fast wave. As stress across the fracture increases, the slow interface wave velocity increases, and the frequency of the spectral peak shifts to higher frequencies. The shear dynamic specific stiffness of the fracture was calculated from the peak energy arrival time as a function of stress. 13 refs., 5 figs., 1 tab

Strength and fracture energy of foamed concrete incorporating rice husk ash and polypropylene mega-mesh 55

Science.gov (United States)

Jaini, Z. M.; Rum, R. H. M.; Boon, K. H.

2017-10-01

This paper presents the utilization of rice husk ash (RHA) as sand replacement and polypropylene mega-mesh 55 (PMM) as fiber reinforcement in foamed concrete. High pozzolanic reaction and the ability to become filler make RHA as a strategic material to enhance the strength and durability of foamed concrete. Furthermore, the presence of PMM optimizes the toughness of foamed concrete in resisting shrinkage and cracking. In this experimental study, cube and cylinder specimens were prepared for the compression and splitting-tensile tests. Meanwhile, notched beam specimens were cast for the three-point bending test. It was found that 40% RHA and 9kg/m3 PMM contribute to the highest strength and fracture energy. The compressive, tensile and flexural strengths are 32MPa, 2.88MPa and 6.68MPa respectively, while the fracture energy achieves 42.19N/m. The results indicate high potential of RHA and PMM in enhancing the mechanical properties of foamed concrete.

The association between genetic variants of RUNX2, ADIPOQ and vertebral fracture in Korean postmenopausal women.

Science.gov (United States)

Kim, Kyong-Chol; Chun, Hyejin; Lai, ChaoQiang; Parnell, Laurence D; Jang, Yangsoo; Lee, Jongho; Ordovas, Jose M

2015-03-01

Contrary to the traditional belief that obesity acts as a protective factor for bone, recent epidemiologic studies have shown that body fat might be a risk factor for osteoporosis and bone fracture. Accordingly, we evaluated the association between the phenotypes of osteoporosis or vertebral fracture and variants of obesity-related genes, peroxisome proliferator-activated receptor-gamma (PPARG), runt-related transcription factor 2 (RUNX2), leptin receptor (LEPR), and adiponectin (ADIPOQ). In total, 907 postmenopausal healthy women, aged 60-79 years, were included in this study. BMD and biomarkers of bone health and adiposity were measured. We genotyped for four single nucleotide polymorphisms (SNPs) from four genes (PPARG, RUNX2, LEPR, ADIPOQ). A general linear model for continuous dependent variables and a logistic regression model for categorical dependent variables were used to analyze the statistical differences among genotype groups. Compared with the TT subjects at rs7771980 in RUNX2, C-carrier (TC + CC) subjects had a lower vertebral fracture risk after adjusting for age, smoking, alcohol, total calorie intake, total energy expenditure, total calcium intake, total fat intake, weight, body fat. Odds ratio (OR) and 95% interval (CI) for the vertebral fracture risk was 0.55 (95% CI 0.32-0.94). After adjusting for multiple variables, the prevalence of vertebral fracture was highest in GG subjects at rs1501299 in ADIPOQ (p = 0.0473). A high calcium intake (>1000 mg/day) contributed to a high bone mineral density (BMD) in GT + TT subjects at rs1501299 in ADIPOQ (p for interaction = 0.0295). Even if the mechanisms between obesity-related genes and bone health are not fully established, the results of our study revealed the association of certain SNPs from obesity-related genes with BMD or vertebral fracture risk in postmenopausal Korean women.

Effects of mineral content on the fracture properties of equine cortical bone in double-notched beams.

Science.gov (United States)

McCormack, Jordan; Stover, Susan M; Gibeling, Jeffery C; Fyhrie, David P

2012-06-01

We recently developed a method to measure cortical bone fracture initiation toughness using a double-notched beam in four-point bending. This method was used to test the hypothesis that mineralization around the two notch roots is correlated with fracture toughness and crack extension (physical damage). Total energy absorbed to failure negatively correlated with average mineralization of the beam (r(2)=0.62), but not with notch root mineralization. Fracture initiation toughness was positively correlated to mineralization at the broken notch root (r(2)=0.34). Crack length extension at the unbroken notch was strongly negatively correlated with the average mineralization of the notch roots (r(2)=0.81) whereas crack length extension at the broken notch did not correlate with any of the mineralization measurements. Mineralization at the notch roots and the average mineralization contributed independently to the mechanical and damage properties. The data are consistent with a hypothesis that a) high notch root mineralization results in less stable crack length extension but high force to initiate unstable crack propagation while b) higher average mineralization leads to low post-yield (and total) energy absorption to failure. Copyright © 2012 Elsevier Inc. All rights reserved.

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)

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...

Hip fracture risk and different gene polymorphisms in the turkish population

Directory of Open Access Journals (Sweden)

Ercan Dinçel

2008-01-01

Full Text Available BACKGROUND: We aimed to discuss the risk assessments for both patients with hip fractures due to fall-related, low energy traumas and non-fractured control patients by examining bone mineral density and genetic data, two features associated with femoral strength and hip fracture risk. METHODS: Twenty-one osteoporotic patients with proximal femur fractures and non-fractured, osteoporotic, age- and gender-matched controls were included in the study. Bone mineral density measurements were performed with a Lunar DXA. The COL1A1, ESR, VDR, IL-6, and OPG genes were amplified, and labeling of specific gene sequences was performed in a multiplex polymerase chain reaction using the osteo/check PCR kit from the whole blood of all subjects. RESULTS: The bone mineral density (trochanteric and total bone mineral density values of the fracture group was significantly decreased relative to the control group. We were not able to conduct statistical tests for the polymorphisms of the COL1A1, ESR, and VDR genes because our results were expressed in terms of frequency. Although they were not significant, we did examine differences in the IL-6 and OPG genes polymorphisms between the two groups. We concluded that increasing the number of cases will allow us to evaluate racial differences in femoral hip fracture risk by genotypes.

Prevalent morphometric vertebral fractures in professional male rugby players.

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Karen Hind

Full Text Available There is an ongoing concern about the risk of injury to the spine in professional rugby players. The objective of this study was to investigate the prevalence of vertebral fracture using vertebral fracture assessment (VFA dual energy X-ray absorptiometry (DXA imaging in professional male rugby players. Ninety five professional rugby league (n = 52 and union (n = 43 players (n = 95; age 25.9 (SD 4.3 years; BMI: 29.5 (SD 2.9 kg.m2 participated in the research. Each participant received one VFA, and one total body and lumbar spine DXA scan (GE Lunar iDXA. One hundred and twenty vertebral fractures were identified in over half of the sample by VFA. Seventy four were graded mild (grade 1, 40 moderate (grade 2 and 6 severe (grade 3. Multiple vertebral fractures (≥2 were found in 37 players (39%. There were no differences in prevalence between codes, or between forwards and backs (both 1.2 v 1.4; p>0.05. The most common sites of fracture were T8 (n = 23, T9 (n = 18 and T10 (n = 21. The mean (SD lumbar spine bone mineral density Z-score was 2.7 (1.3 indicating high player bone mass in comparison with age- and sex-matched norms. We observed a high number of vertebral fractures using DXA VFA in professional rugby players of both codes. The incidence, aetiology and consequences of vertebral fractures in professional rugby players are unclear, and warrant timely, prospective investigation.

On size effects in fracture

International Nuclear Information System (INIS)

Sinclair, G.B.

1985-01-01

This paper discusses the dependence of fracture stress on size. This conclusion is based on classical energy arguments. For an in-plane scaled specimen pair, the larger the specimen the smaller the fracture stress. In contrast the same theory gives a different dependence for out-of-plane specimen and the dependence involves plane stress, strain, fracture stresses and Poisson's ratio. The objective of this paper is to examine how well these predictions are actually complied with

Increased risk for early periprosthetic fractures after uncemented total hip replacement

DEFF Research Database (Denmark)

Solgaard, Søren; Kjersgaard, Anne Grete

2014-01-01

in women. No correlation with diagnosis, age, body mass index, operation time, operative technique or implant position could be demonstrated, but a possible correlation with post-operative mobilisation and pain treatment was observed. Trainees had more fractures than experienced surgeons (non...

Strengths and strain energies of volcanic edifices: implications for eruptions, collapse calderas, and landslides

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A. Gudmundsson

2012-07-01

Full Text Available Natural hazards associated with volcanic edifices depend partly on how fracture resistant the edifices are, i.e. on their strengths. Observations worldwide indicate that large fluid-driven extension fractures (dikes, inclined sheets, shear fractures (landslides, and mixed-mode fractures (ring dikes and ring faults normally propagate more easily in a basaltic edifice (shield volcano than in a stratovolcano. For example, dike-fed eruptions occur once every few years in many basaltic edifices but once every 10^2-3 yr in many stratovolcanoes. Large landslides and caldera collapses also appear to be more common in a typical basaltic edifice/shield volcano than in a typical stratovolcano. In contrast to a basaltic edifice, a stratovolcano is composed of mechanically dissimilar rock layers, i.e. layers with mismatching elastic properties (primarily Young's modulus. Elastic mismatch encourages fracture deflection and arrest at contacts and increases the amount of energy needed for a large-scale edifice failure. Fracture-related hazards depend on the potential energy available to propagate the fractures which, in turn, depends on the boundary conditions during fracture propagation. Here there are two possible scenarios: one in which the outer boundary of the volcanic edifice or rift zone does not move during the fracture propagation (constant displacement; the other in which the boundary moves (constant load. In the former, the total potential energy is the strain energy stored in the volcano before fracture formation; in the latter, the total potential energy is the strain energy plus the work done by the forces moving the boundary. Constant-displacement boundary conditions favor small eruptions, landslides, and caldera collapses, whereas constant-load conditions favor comparatively large eruptions, landslides, and collapses. For a typical magma chamber (sill-like with a diameter of 8 km, the strain energy change due to magma-chamber inflation

[Catheter fracture and pulmonary embolization of the distal fragment: a rare complication of the totally implantable venous access port].

Science.gov (United States)

Rebahi, H; El Adib, A G; Mouaffak, Y; El Hattaoui, M; Chaara, A; Sadek, H; Khouchani, M; Mahmal, L; Younous, S

2015-01-01

Totally implantable venous access port plays a crucial role in the treatment of patients in oncology. However, its use can result sporadically in catheter fracture with catheter tip embolization into pulmonary arteries. We report this unusual but potentially serious complication in four patients. In these patients, the port had been inserted percutaneously into the subclavian vein using the infra-clavicular approach. This side effect occurred late in three patients. In all patients, the catheter fracture was asymptomatic or pauci-symptomatic and was caused by the pinch-off syndrome. The retrieval of the embolized fragments was successfully performed by transcatheter procedure in the cardiac catheterisation laboratory. We reviewed the literature and the newest guidelines and recommendations to detail the clinico-radiological features, the possible causes of this complication and discussed means to recognize, manage and prevent it. Copyright © 2013 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.

Mechanical test and fractal analysis on anisotropic fracture of cortical bone

International Nuclear Information System (INIS)

Yin, Dagang; Chen, Bin; Ye, Wei; Gou, Jihua; Fan, Jinghong

2015-01-01

Highlights: • The mechanical properties of the cortical bone of fresh bovine femora along three different directions are tested through four-point bending experiments. • SEM observation shows that the roughness of the fracture surfaces of the three different directions of the bone are remarkably different. • The fractal dimensions of the different fracture surfaces of the bone are calculated by box-counting method in MATLAB. • The fracture energies of the different fracture directions are calculated based on their fractal models. - Abstract: The mechanical properties of the cortical bone of fresh bovine femora along three different directions are tested through four-point bending experiments. It is indicated that the fracture energy along the transversal direction of the bone is distinctly larger than those of the longitudinal and radial directions. The fracture surfaces of the three different directions are observed by scanning electron microscope (SEM). It is shown that the roughness of the fracture surface of the transversal direction is obviously larger than those of the fracture surfaces of the longitudinal and radial directions. It is also revealed that the osteons in the bone are perpendicular to the fracture surface of the transversal direction and parallel to the fracture surfaces of the longitudinal and radial directions. Based on these experimental results, the fractal dimensions of the fracture surfaces of different directions are calculated by box-counting method in MATLAB. The calculated results show that the fractal dimension of the fracture surface of the transversal direction is remarkably larger than those of the fracture surfaces of the longitudinal and radial directions. The fracture energies of different directions are also calculated based on their fractal models. It is denoted that the fracture energy of the transversal direction is remarkably larger than those of the longitudinal and radial directions. The calculated results are in

Mechanical test and fractal analysis on anisotropic fracture of cortical bone

Energy Technology Data Exchange (ETDEWEB)

Yin, Dagang [State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044 (China); College of Aerospace Engineering, Chongqing University, Chongqing 400044 (China); Chen, Bin, E-mail: bchen@cqu.edu.cn [State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044 (China); College of Aerospace Engineering, Chongqing University, Chongqing 400044 (China); Ye, Wei [College of Aerospace Engineering, Chongqing University, Chongqing 400044 (China); Gou, Jihua [Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States); Fan, Jinghong [Division of Mechanical Engineering, Alfred University, Alfred, NY 14802 (United States)

2015-12-01

Highlights: • The mechanical properties of the cortical bone of fresh bovine femora along three different directions are tested through four-point bending experiments. • SEM observation shows that the roughness of the fracture surfaces of the three different directions of the bone are remarkably different. • The fractal dimensions of the different fracture surfaces of the bone are calculated by box-counting method in MATLAB. • The fracture energies of the different fracture directions are calculated based on their fractal models. - Abstract: The mechanical properties of the cortical bone of fresh bovine femora along three different directions are tested through four-point bending experiments. It is indicated that the fracture energy along the transversal direction of the bone is distinctly larger than those of the longitudinal and radial directions. The fracture surfaces of the three different directions are observed by scanning electron microscope (SEM). It is shown that the roughness of the fracture surface of the transversal direction is obviously larger than those of the fracture surfaces of the longitudinal and radial directions. It is also revealed that the osteons in the bone are perpendicular to the fracture surface of the transversal direction and parallel to the fracture surfaces of the longitudinal and radial directions. Based on these experimental results, the fractal dimensions of the fracture surfaces of different directions are calculated by box-counting method in MATLAB. The calculated results show that the fractal dimension of the fracture surface of the transversal direction is remarkably larger than those of the fracture surfaces of the longitudinal and radial directions. The fracture energies of different directions are also calculated based on their fractal models. It is denoted that the fracture energy of the transversal direction is remarkably larger than those of the longitudinal and radial directions. The calculated results are in

Hidden blood loss after surgery for hip fracture

DEFF Research Database (Denmark)

Foss, N B; Kehlet, H

2006-01-01

Our aim was to determine the total blood loss associated with surgery for fracture of the hip and to identify risk factors for increased blood loss. We prospectively studied 546 patients with hip fracture. The total blood loss was calculated on the basis of the haemoglobin difference, the number...

EXTERNAL FIXATION OF METACARPAL AND PHALANGAL FRACTURES

Directory of Open Access Journals (Sweden)

Krunoslav Margić

2001-11-01

Full Text Available Background. In past three years we have used smallexternal fixator in the treatment of: 18 closed fractures of metacarpalbones, 15 phalangeal fractures, four dislocated fracturesof MCP and five of PIP joint, ten arthrodesis, five replantations/revascularisations, two pathological fractures, and infew post-traumatic infection of bones and joints.Results. Results were graded as excellent (completely normalfunction, very good (15° deficit of total ROM, good (30° deficitof total ROM; can flex the fingers to the palm, and poor.Excellent result was obtained in the treatment of all 18 metacarpalfractures. The final results in the treatment of 12 closedfragmentated fractures of phalanges were as follows: excellent3, very good 2, good 2 and five poor results (three patientsin this group have fallen on their hands causing refractureand reoperation. Three of four fractures of MCP joint andfour of five fractures involving PIP joint have good mobility.In eight of ten patients arthrodeses are stable and withoutpain. In two cases pathological fractures were first stabilizedand than the tumor was evacuated and grafted with minimaldissection; booth have good results.Conclusion. Author suggests that, in selected cases, with applicationof small external fixator reasonable good results can beobtained.

From brittle to ductile fracture in disordered materials.

Science.gov (United States)

Picallo, Clara B; López, Juan M; Zapperi, Stefano; Alava, Mikko J

2010-10-08

We introduce a lattice model able to describe damage and yielding in heterogeneous materials ranging from brittle to ductile ones. Ductile fracture surfaces, obtained when the system breaks once the strain is completely localized, are shown to correspond to minimum energy surfaces. The similarity of the resulting fracture paths to the limits of brittle fracture or minimum energy surfaces is quantified. The model exhibits a smooth transition from brittleness to ductility. The dynamics of yielding exhibits avalanches with a power-law distribution.

Atypical femoral fractures related to bisphosphonate therapy

Directory of Open Access Journals (Sweden)

Tarun Pankaj Jain

2012-01-01

Full Text Available Bisphosphonates (BP are a commonly prescribed class of drugs for the prevention of osteoporosis-related fractures. Paradoxically, however, they have recently been linked to atypical fractures in the shaft of the femur. Since many physicians including radiologists, are not aware of this entity, the incidence is likely underreported. These fractures usually occur in the sub-trochanteric region of the femur in the setting of low-energy trauma. It starts as a fracture line involving the lateral cortex and then progresses medially to give rise to a complete fracture. The fracture line is usually transverse, and there is a medial spike associated with a complete fracture. These fractures can be bilateral. Awareness of these atypical fractures and their radiological appearance should enable their early and accurate detection and thus lead to specific treatment.

[Treatment of posterior cruciate ligament avulsion fracture with rivet-assisted hollow nail:a case-control study].

Science.gov (United States)

Zhu, Jia-Fu; Ma, Gou-Ping; Xu, Wei-Xing; Guo, Qiao-Feng; Liu, Hong

2017-04-25

To retrospectively investigate the clinical effect of the rivet-assisted hollow screw in the treatment of posterior cruciate ligament avulsion fracture. Total 49 patients with knee cruciate ligament avulsion fracture in the ending point of the ligament from January 2010 to December 2014 were divided into the treatment group and the control group. Thirty-one patients in treatment group were treated with rivet-assisted double cannulate nail, including 13 males and 18 females, ranging in age from 38 to 51 years old, with a mean of (40.6±5.1) years old; according to Meyers classification, 23 cases of type 2, 8 cases of type 3; 5 patients were caused by the low energy injury and 26 patients were caused by the high energy injury. Eighteen patients in control group were treated with double gold hollow screw fixation, including 5 males and 13 females, ranging in age from 36 to 52 years old, with an average age of (4.16±4.7) years old; according to Meyers classification, 14 cases of type 2 and 4 cases of type 3;2 patients were caused by the low energy injury and 16 patients were caused by the high energy injury. The operation time, postoperative complications, fracture healing time and the last AKS scoring system were compared between the two groups. All the patients were followed up, and the duration ranged from 12 to 24 months, with an average of 14.2 months. The patients in treatment group had no displacement of fracture fragments and internal fixation failure. The results of AKS score:pain was 48.1±1.5, activity was 21.3±2.7, stability was 20.9±2.5, walking ability was 47.3±1.9, under the stairs ability was 43.4±2.1, the total score was 190.7±2.9. There were 2 cases in control group had fracture fragment displacement and 1 patient had nail withdraw. The results of AKS score:pain was 40.1±2.2, activity was 20.1±0.2, stability was 18.1±3.2, walking ability was 46.3±1.7, under the stairs ability was 40.2 ±1.3, the total score was 180.2±1.4. Therefore, the

Total energy calculations and bonding at interfaces

International Nuclear Information System (INIS)

Louie, S.G.

1984-08-01

Some of the concepts and theoretical techniques employed in recent ab initio studies of the electronic and structural properties of surfaces and interfaces are discussed. Results of total energy calculations for the 2 x 1 reconstructed diamond (111) surface and for stacking faults in Si are reviewed. 30 refs., 8 figs

Fracture fixation in the operative management of hip fractures (FAITH): an international, multicentre, randomised controlled trial

OpenAIRE

Nauth, A. (Aaron); Creek, A.T. (Aaron T.); Zellar, A. (Abby); Lawendy, A.-R. (Abdel-Rahman); Dowrick, A. (Adam); Gupta, A. (Ajay); Dadi, A. (Akhil); Kampen, A.; Yee, A. (Albert); Vries, Alexander; de Mol van Otterloo, A. (Alexander); Garibaldi, A. (Alisha); Liew, A. (Allen); McIntyre, A.W. (Allison W.); Prasad, A.S. (Amal Shankar)

2017-01-01

textabstractBackground Reoperation rates are high after surgery for hip fractures. We investigated the effect of a sliding hip screw versus cancellous screws on the risk of reoperation and other key outcomes. Methods For this international, multicentre, allocation concealed randomised controlled trial, we enrolled patients aged 50 years or older with a low-energy hip fracture requiring fracture fixation from 81 clinical centres in eight countries. Patients were assigned by minimisation with a...

Long-bone fractures in persons with spinal cord injury.

Science.gov (United States)

Frotzler, A; Cheikh-Sarraf, B; Pourtehrani, M; Krebs, J; Lippuner, K

2015-09-01

Retrospective data analysis. To document fracture characteristics, management and related complications in individuals with traumatic spinal cord injury (SCI). Rehabilitation centre for SCI individuals. Patients' records were reviewed. Patients with traumatic SCI and extremity fractures that had occurred after SCI were included. Patient characteristics, fractured bone, fracture localisation, severity and management (operative/conservative), and fracture-related complications were extracted. A total of 156 long-bone fractures in 107 SCI patients (34 women and 73 men) were identified. The majority of patients were paraplegics (77.6%) and classified as American Spinal Injury Association Impairment Scale A (86.0%). Only the lower extremities were affected, whereby the femur (60.9% of all fractures) was fractured more frequently than the lower leg (39.1%). A total of 70 patients (65.4%) had one fracture, whereas 37 patients (34.6%) had two or more fractures. Simple or extraarticular fractures were most common (75.0%). Overall, 130 (83.3%) fractures were managed operatively. Approximately half of the femur fractures (48.2%) were treated with locking compression plates. In the lower leg, fractures were mainly managed with external fixation (48.8%). Conservative fracture management was applied in 16.7% of the cases and consisted of braces or a well-padded soft cast. Fracture-associated complications were present in 13.5% of the cases but did not differ significantly between operative (13.1%) and conservative (15.4%) fracture management. SCI was associated with simple or extraarticular fractures of the distal femur and the lower leg. Fractures were mainly managed operatively with a low complication rate.

Poynting Theorem, Relativistic Transformation of Total Energy-Momentum and Electromagnetic Energy-Momentum Tensor

Science.gov (United States)

Kholmetskii, Alexander; Missevitch, Oleg; Yarman, Tolga

2016-02-01

We address to the Poynting theorem for the bound (velocity-dependent) electromagnetic field, and demonstrate that the standard expressions for the electromagnetic energy flux and related field momentum, in general, come into the contradiction with the relativistic transformation of four-vector of total energy-momentum. We show that this inconsistency stems from the incorrect application of Poynting theorem to a system of discrete point-like charges, when the terms of self-interaction in the product {\\varvec{j}} \\cdot {\\varvec{E}} (where the current density {\\varvec{j}} and bound electric field {\\varvec{E}} are generated by the same source charge) are exogenously omitted. Implementing a transformation of the Poynting theorem to the form, where the terms of self-interaction are eliminated via Maxwell equations and vector calculus in a mathematically rigorous way (Kholmetskii et al., Phys Scr 83:055406, 2011), we obtained a novel expression for field momentum, which is fully compatible with the Lorentz transformation for total energy-momentum. The results obtained are discussed along with the novel expression for the electromagnetic energy-momentum tensor.

Scaphoid fractures in children

Directory of Open Access Journals (Sweden)

Gajdobranski Đorđe

2014-01-01

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

Comminution of solids caused by kinetic energy of high shear strain rate, with implications for impact, shock, and shale fracturing.

Science.gov (United States)

Bazant, Zdenek P; Caner, Ferhun C

2013-11-26

Although there exists a vast literature on the dynamic comminution or fragmentation of rocks, concrete, metals, and ceramics, none of the known models suffices for macroscopic dynamic finite element analysis. This paper outlines the basic idea of the macroscopic model. Unlike static fracture, in which the driving force is the release of strain energy, here the essential idea is that the driving force of comminution under high-rate compression is the release of the local kinetic energy of shear strain rate. The density of this energy at strain rates >1,000/s is found to exceed the maximum possible strain energy density by orders of magnitude, making the strain energy irrelevant. It is shown that particle size is proportional to the -2/3 power of the shear strain rate and the 2/3 power of the interface fracture energy or interface shear stress, and that the comminution process is macroscopically equivalent to an apparent shear viscosity that is proportional (at constant interface stress) to the -1/3 power of this rate. A dimensionless indicator of the comminution intensity is formulated. The theory was inspired by noting that the local kinetic energy of shear strain rate plays a role analogous to the local kinetic energy of eddies in turbulent flow.

Energy-analysis of the total nuclear energy cycle based on light water reactors

International Nuclear Information System (INIS)

Kistemaker, J.

1975-01-01

The energy economy of the total nuclear energy cycle is investigated. Attention is paid to the importance of fossil fuel saving by using nuclear energy. The energy analysis is based on the construction and operation of power plants with an electric output of 1000MWe. Light water moderated reactors with a 2.7 - 3.2% enriched uranium core are considered. Additionally, the whole fuel cycle including ore winning and refining, enrichment and fuel element manufacturing and reprocessing has been taken into account. Neither radioactive waste storage problems nor safety problems related to the nuclear energy cycle and safeguarding have been dealt with, as exhaustive treatments can be found elswhere

Formation fracturing by energy waves

Energy Technology Data Exchange (ETDEWEB)

Brandon, C W

1966-11-28

A method described for recovering oil from an oil strata penetrated by a well bore includes a step of applying fluid pressure to the interior of the well bore across the face of the stratum, and alternately varying the applied fluid pressure, first above and then below the reservoir pressure. This is in order to fracture and break up the face of the strata from internal pressure exerted on the strata. The pressure is affected using liquefied gas at low pressure across the formation.

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.

Avalanche weak layer shear fracture parameters from the cohesive crack model

Science.gov (United States)

McClung, David

2014-05-01

Dry slab avalanches release by mode II shear fracture within thin weak layers under cohesive snow slabs. The important fracture parameters include: nominal shear strength, mode II fracture toughness and mode II fracture energy. Alpine snow is not an elastic material unless the rate of deformation is very high. For natural avalanche release, it would not be possible that the fracture parameters can be considered as from classical fracture mechanics from an elastic framework. The strong rate dependence of alpine snow implies that it is a quasi-brittle material (Bažant et al., 2003) with an important size effect on nominal shear strength. Further, the rate of deformation for release of an avalanche is unknown, so it is not possible to calculate the fracture parameters for avalanche release from any model which requires the effective elastic modulus. The cohesive crack model does not require the modulus to be known to estimate the fracture energy. In this paper, the cohesive crack model was used to calculate the mode II fracture energy as a function of a brittleness number and nominal shear strength values calculated from slab avalanche fracture line data (60 with natural triggers; 191 with a mix of triggers). The brittleness number models the ratio of the approximate peak value of shear strength to nominal shear strength. A high brittleness number (> 10) represents large size relative to fracture process zone (FPZ) size and the implications of LEFM (Linear Elastic Fracture Mechanics). A low brittleness number (e.g. 0.1) represents small sample size and primarily plastic response. An intermediate value (e.g. 5) implies non-linear fracture mechanics with intermediate relative size. The calculations also implied effective values for the modulus and the critical shear fracture toughness as functions of the brittleness number. The results showed that the effective mode II fracture energy may vary by two orders of magnitude for alpine snow with median values ranging from 0

[Trochanteric femoral fractures: anatomy, biomechanics and choice of implants].

Science.gov (United States)

Bonnaire, F; Lein, T; Bula, P

2011-06-01

The objective of any surgical care of a trochanteric femoral fracture should be the achievement of a stable osteosynthesis that allows early full weight-bearing mobilisation of the patient, because long-term immobilisation soon becomes a vital threat to the affected patients who are usually elderly with correlating comorbidities. The anatomical references of the proximal femur and the structure of the hip joint contain some specifics that play an essential role in the incurrence of a trochanteric femoral fracture and the planning of the osteosynthesis as well. With reposition and fracture stabilisation particular importance must be attached to the collo-diaphyseal and the antetorsion angle so that they do not interfere with the functional interaction of the hip and knee joint. Uncomplex trochanteric fractures ordinarily stabilise sufficiently after reposition so that even an extramedullary implant can ensure full weight-bearing stability. With evermore distal fracture course and intertrochanteric comminution zone, rotational instability and pivot transfer of the fracture area to lateral and caudal are followed by an increase of the dislocating forces. These kinds of fractures (A2 and A3 according to the AO/ASIF classification) profit from an intramedullary and rotationally stable osteosynthesis. Basically primary total hip arthroplasty is a potential option for surgical care of a trochanteric fracture in elderly patients with relevant coxarthrosis. However this procedure can only be recommended in cases of a stable uncomplex fracture. The more the medial interlocking of the proximal femur is destroyed the more difficult it will be to primarily implant a total hip prosthesis with good offset and without a varus and rotational failure in the fracture zone.The current studies in the main show disadvantages due to increased complications in these patients, so that in cases of an unstable trochanteric fracture a primary osteosynthesis should be performed followed by

Understanding hydraulic fracturing: a multi-scale problem

Science.gov (United States)

Hyman, J. D.; Jiménez-Martínez, J.; Viswanathan, H. S.; Carey, J. W.; Porter, M. L.; Rougier, E.; Karra, S.; Kang, Q.; Frash, L.; Chen, L.; Lei, Z.; O’Malley, D.; Makedonska, N.

2016-01-01

Despite the impact that hydraulic fracturing has had on the energy sector, the physical mechanisms that control its efficiency and environmental impacts remain poorly understood in part because the length scales involved range from nanometres to kilometres. We characterize flow and transport in shale formations across and between these scales using integrated computational, theoretical and experimental efforts/methods. At the field scale, we use discrete fracture network modelling to simulate production of a hydraulically fractured well from a fracture network that is based on the site characterization of a shale gas reservoir. At the core scale, we use triaxial fracture experiments and a finite-discrete element model to study dynamic fracture/crack propagation in low permeability shale. We use lattice Boltzmann pore-scale simulations and microfluidic experiments in both synthetic and shale rock micromodels to study pore-scale flow and transport phenomena, including multi-phase flow and fluids mixing. A mechanistic description and integration of these multiple scales is required for accurate predictions of production and the eventual optimization of hydrocarbon extraction from unconventional reservoirs. Finally, we discuss the potential of CO2 as an alternative working fluid, both in fracturing and re-stimulating activities, beyond its environmental advantages. This article is part of the themed issue ‘Energy and the subsurface’. PMID:27597789

Minimally-invasive plate osteosynthesis in distal tibial fractures: Results and complications.

Science.gov (United States)

Vidović, Dinko; Matejčić, Aljoša; Ivica, Mihovil; Jurišić, Darko; Elabjer, Esmat; Bakota, Bore

2015-11-01

Distal tibial or pilon fractures are usually the result of combined compressive and shear forces, and may result in instability of the metaphysis, with or without articular depression, and injury to the soft tissue. The complexity of injury, lack of muscle cover and poor vascularity make these fractures difficult to treat. Surgical treatment of distal tibial fractures includes several options: external fixation, IM nailing, ORIF and minimally-invasive plate osteosynthesis (MIPO). Management of distal tibial fractures with MIPO enables preservation of soft tissue and remaining blood supply. This is a report of a series of prospectively studied closed distal tibial and pilon fractures treated with MIPO. A total of 21 patients with closed distal tibial or pilon fractures were enrolled in the study between March 2008 and November 2013 and completed follow-up. Demographic characteristics, mechanism of injury, time required for union, ankle range of motion and complications were recorded. Fractures were classified according to the AO/OTA classification. Nineteen patients were initially managed with an ankle-spanning external fixator. When the status of the soft tissue had improved and swelling had subsided enough, a definitive internal fixation with MIPO was performed. Patients were invited for follow-up examinations at 3 and 6 weeks and then at intervals of 6 to 8 weeks until 12 months. Mean age of the patients was 40.1 years (range 19-67 years). Eighteen cases were the result of high-energy trauma and three were the result of low-energy trauma. According to the AO/OTA classification there were extraarticular and intraarticular fractures, but only simple articular patterns without depression or comminution. The average time for fracture union was 19.7 weeks (range 12-38 weeks). Mean range of motion was 10° of dorsiflexion (range 5-15°) and 28.3° of plantar flexion (range 20-35°). Three cases were metalwork-related complications. Two patients underwent plate removal

A rare type of ankle fracture: Syndesmotic rupture combined with a high fibular fracture without medial injury.

Science.gov (United States)

van Wessem, K J P; Leenen, L P H

2016-03-01

High fibular spiral fractures are usually caused by pronation-external rotation mechanism. The foot is in pronation and the talus externally rotates, causing a rupture of the medial ligaments or a fracture of the medial malleolus. With continued rotation the anterior and posterior tibiofibular ligament will rupture, and finally, the energy leaves the fibula by creating a spiral fracture from anterior superior to posterior inferior. In this article we demonstrate a type of ankle fracture with syndesmotic injury and high fibular spiral fractures without a medial component. This type of ankle fractures cannot be explained by the Lauge-Hansen classification, since it lacks injury on the medial side of the ankle, but it does have the fibular fracture pattern matching the pronation external rotation injury (anterior superior to posterior inferior fracture). We investigated the mechanism of this injury illustrated by 3 cases and postulate a theory explaining the biomechanics behind this type of injury. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Cost-Effectiveness Analysis of Reverse Total Shoulder Arthroplasty versus Hemiarthroplasty for the Management of Complex Proximal Humeral Fractures in the Elderly.

Science.gov (United States)

Osterhoff, Georg; O'Hara, Nathan N; D'Cruz, Jennifer; Sprague, Sheila A; Bansback, Nick; Evaniew, Nathan; Slobogean, Gerard P

2017-03-01

There is ongoing debate regarding the optimal surgical treatment of complex proximal humeral fractures in elderly patients. To evaluate the cost-effectiveness of reverse total shoulder arthroplasty (RTSA) compared with hemiarthroplasty (HA) in the management of complex proximal humeral fractures, using a cost-utility analysis. On the basis of data from published literature, a cost-utility analysis was conducted using decision tree and Markov modeling. A single-payer perspective, with a willingness-to-pay (WTP) threshold of Can$50,000 (Canadian dollars), and a lifetime time horizon were used. The incremental cost-effectiveness ratio (ICER) was used as the study's primary outcome measure. In comparison with HA, the incremental cost per quality-adjusted life-year gained for RTSA was Can$13,679. One-way sensitivity analysis revealed the model to be sensitive to the RTSA implant cost and the RTSA procedural cost. The ICER of Can$13,679 is well below the WTP threshold of Can$50,000, and probabilistic sensitivity analysis demonstrated that 92.6% of model simulations favored RTSA. Our economic analysis found that RTSA for the treatment of complex proximal humeral fractures in the elderly is the preferred economic strategy when compared with HA. The ICER of RTSA is well below standard WTP thresholds, and its estimate of cost-effectiveness is similar to other highly successful orthopedic strategies such as total hip arthroplasty for the treatment of hip arthritis. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Acoustic emission characterization of fracture toughness for fiber reinforced ceramic matrix composites

International Nuclear Information System (INIS)

Mei, Hui; Sun, Yuyao; Zhang, Lidong; Wang, Hongqin; Cheng, Laifei

2013-01-01

The fracture toughness of a carbon fiber reinforced silicon carbide composite was investigated relating to classical critical stress intensity factor K IC , work of fracture, and acoustic emission energy. The K IC was obtained by the single edge notch beam method and the work of fracture was calculated using the featured area under the load–displacement curves. The K IC , work of fracture, and acoustic emission energy were compared for the composites before and after heat treatment and then analyzed associated with toughening microstructures of fiber pullout. It indicates that the work of fracture and acoustic emission energy can be more suitable to reflect the toughness rather than the traditional K IC , which has certain limitation for the fracture toughness characterization of the crack tolerant fiber ceramic composites.

Characterization of the chemicals used in hydraulic fracturing fluids for wells located in the Marcellus Shale Play.

Science.gov (United States)

Chen, Huan; Carter, Kimberly E

2017-09-15

Hydraulic fracturing, coupled with the advances in horizontal drilling, has been used for recovering oil and natural gas from shale formations and has aided in increasing the production of these energy resources. The large volumes of hydraulic fracturing fluids used in this technology contain chemical additives, which may be toxic organics or produce toxic degradation byproducts. This paper investigated the chemicals introduced into the hydraulic fracturing fluids for completed wells located in Pennsylvania and West Virginia from data provided by the well operators. The results showed a total of 5071 wells, with average water volumes of 5,383,743 ± 2,789,077 gal (mean ± standard deviation). A total of 517 chemicals was introduced into the formulated hydraulic fracturing fluids. Of the 517 chemicals listed by the operators, 96 were inorganic compounds, 358 chemicals were organic species, and the remaining 63 cannot be identified. Many toxic organics were used in the hydraulic fracturing fluids. Some of them are carcinogenic, including formaldehyde, naphthalene, and acrylamide. The degradation of alkylphenol ethoxylates would produce more toxic, persistent, and estrogenic intermediates. Acrylamide monomer as a primary degradation intermediate of polyacrylamides is carcinogenic. Most of the chemicals appearing in the hydraulic fracturing fluids can be removed when adopting the appropriate treatments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biomass energy in Jordan, and its potential contribution towards the total energy mix of the Kingdom

International Nuclear Information System (INIS)

Al-Dabbas, Moh'd A. F.

1994-04-01

An evaluation of Jordan's bio-energy status was carried out. Available sources and the viability of exploitation were studied in order to identify the size of contribution that bio-energy could provide to the total energy mix of the Kingdom. The advantages of biogas technology were discussed, and a general description of Jordan's experience in this field was presented. Data on Jordan' animal, municipal, and agricultural wastes that are available as a potential source of bio-energy was tabulated. The report ascertained the economic feasibility of biogas utilization in Jordan, and concluded that the annual energy production potential from biogas, with only animal wastes being utilized, would amount to 80,000 ton oil equivalent. This amount of energy is equivalent to 2% of Jordan's total energy consumption in 1992. The utilization of biogas from municipal wastes would produce an additional 2.5% of the total energy consumption of Jordan. The annual value of utilizing animal and municipal wastes would reach 23 million Jordanian Dinars (JD). This value would increase to 61.5 million JD with the utilization of human wastes. The investment required for the utilization of bio-energy sources in Amman and its suburbs on the scale of family unit fermenters was estimated to be in the order of a million JD. The size of investment for industrial scale utilization for power generation with an electricity feed to the national grid, would range from 3 to 4 million JD. (A.M.H.). 8 refs., 4 tabs

A Holistic Assessment of Energy Production: Environmental, Economic, and Social Impacts of Hydraulic Fracturing in Williams County, North Dakota

Science.gov (United States)

Jagdeo, J.; Ravikumar, A. P.; Grubert, E.; Brandt, A. R.

2016-12-01

Unconventional oil and natural gas production in the U.S. has increased tenfold between 2005 and 2014 due to advances in hydraulic fracturing technology. Prior studies of hydraulic fracturing activity have mainly focused on two themes: the environmental impacts related to air and water pollution or the direct and spillover economic benefits resulting from oil booms at the state and local level. However, the impacts of hydraulic fracturing extend beyond these effects. Oil-boom counties have experienced environmental changes in land-use and water supply and witnessed social changes in demographics, crime, and health, factors that are not typically evaluated in regard to hydraulic fracturing. Hence, there is a need to consider the holistic effects of oil production on communities. This study examines the environmental, economic, and social impacts of oil and gas activity in Williams County, North Dakota by comparing its pre-boom ( 2005) and post-boom ( 2014) conditions. Annual oil production in Williams County increased from 3.4 million barrels in 2005 to 56 million barrels in 2014, providing an ideal test-case to study the impact of energy development on surrounding communities. We compared changes in multiple impact categories, attributed directly or indirectly to hydraulic fracturing activity, to trends at the national level. For example, between 2005 and 2014, CO2 and CH4 emissions primarily from oil and gas activity increased by 360 thousand metric tons CO2e, corresponding to a 20-fold increase. Concurrently, national emissions decreased by 10.5%. Over twenty indicators were analyzed across environmental, social and economic impact categories, including land-use change, median household income, and crime rates. The datasets were normalized using federal regulations for upper and lower bounds, or calibrated against national averages. Normalized indicators are then aggregated to provide a single-value `impact-factor'. Such `impact-factor' maps will provide a

Factors affecting bone mineral mass loss after lower-limb fractures in a pediatric population.

Science.gov (United States)

Ceroni, Dimitri; Martin, Xavier; Kherad, Omar; Salvo, Davide; Dubois-Ferrière, Victor

2015-06-01

The purpose of this study was to assess the effects of the durations of cast immobilization and non-weight-bearing periods, and decreases in vigorous physical activity (VPA) on bone mineral parameters in a pediatric population treated for a lower-limb fracture. Fifty children and teenagers who had undergone a cast-mediated immobilization for a leg or ankle fracture were prospectively recruited. The durations of cast immobilization and non-weight-bearing periods were recorded for each participant. Dual-energy x-ray absorptiometry scans were performed at the time of fracture treatment (baseline) and at cast removal. Physical activity during cast immobilization was assessed using accelerometers. A strong negative correlation was found between the total duration of cast immobilization and decreases in both calcaneal bone mineral density (BMD) (r=-0.497) and total lower-limb bone mineral content (BMC) (r=-0.405). A strong negative correlation was also noted between the durations of the non-weight-bearing periods and alterations in calcaneal BMD (r=-0.420). No apparent correlations were found between lower BMD and BMC and decreased VPA. Bone mineral loss was correlated to the total duration of cast immobilization for all measurement sites on the affected leg, whereas it was only correlated to the durations of non-weight-bearing periods for calcaneal BMD and total lower-limb BMC. However, no correlations were noted between bone mineral loss and decreased VPA.

Fracture behaviour of heat cured fly ash based geopolymer concrete

International Nuclear Information System (INIS)

Sarker, Prabir K.; Haque, Rashedul; Ramgolam, Karamchand V.

2013-01-01

Highlights: ► Fly ash geopolymer (GPC) can help reduce carbon footprint of concrete. ► Fracture behaviour of GPC as compared to OPC concrete was studied. ► Fracture energy of GPC was similar to that of OPC concrete. ► GPC showed higher fracture toughness than OPC concrete. ► Higher bond strength resulted in higher crack resistance of GPC. -- Abstract: Use of fly ash based geopolymer as an alternative binder can help reduce CO 2 emission of concrete. The binder of geopolymer concrete (GPC) is different from that of ordinary Portland cement (OPC) concrete. Thus, it is necessary to study the effects of the geopolymer binder on the behaviour of concrete. In this study, the effect of the geopolymer binder on fracture characteristics of concrete has been investigated by three point bending test of RILEM TC 50 – FMC type notched beam specimens. The peak load was generally higher in the GPC specimens than the OPC concrete specimens of similar compressive strength. The failure modes of the GPC specimens were found to be more brittle with relatively smooth fracture planes as compared to the OPC concrete specimens. The post-peak parts of the load–deflection curves of GPC specimens were steeper than that of OPC concrete specimens. Fracture energy calculated by the work of fracture method was found to be similar in both types of concrete. Available equations for fracture energy of OPC concrete yielded conservative estimations of fracture energy of GPC. The critical stress intensity factor of GPC was found to be higher than that of OPC concrete. The different fracture behaviour of GPC is mainly because of its higher tensile strength and bond strength than OPC concrete of the same compressive strength.

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

Dependence of hardness and impact energy on cooling time Δt8/5and temperature for S960QL

OpenAIRE

Samardžić, I.; Dunđer, M.; Vuherer, T.

2015-01-01

The paper deals with research into dependence of hardness and impact energy of thermal cycle simulated specimens of fine-grained structural steel S960QL on cooling time from 800 to 500 °C and on tested temperature. Results were obtained by measuring hardness of HV 10 and by experimental testing of Charpy notched tubes on instrumented Charpy hammer. Total impact energy, initiation energy and fracture propagation energy needed for occurrence of fracture is also elaborated. Key words:

Influence of irradiation on microyielding and fracture of polycrystalline MgO

International Nuclear Information System (INIS)

Ibrahim, N.A.; Tangri, K.

1976-01-01

Detailed study of the microstructural features characterizing microyielding and fracture in polycrystalline MgO is reported for the material in irradiated and unirradiated conditions. In both materials fracture is preceded by plastic flow, and intergranular cracks are initiated by slip bands encountering unfavourably oriented grains. The data provide direct evidence for three irreversible energy dissipating processes associated with fracture. These are: generation of plastic zones; formation of secondary cracks; and creation of discrete microcracks. Irradiation is found to produce two competing effects; it it increases the stress required to initiate fracture and decreases the irreversible energy expenditure during crack extension. A linear relationship between fracture stress and (grain diameter)sup(-1/2) is found for the irradiated material but a non-linear behaviour is observed for the unirradiated material. The behaviour in the unirradiated material is explained in terms of dependence off γsub(irr) (excess surface energy due to various irreversible energy dissipating processes) on grain size. (author)

Management of Severe Perineal Injuries in Major Pelvic Fractures

Directory of Open Access Journals (Sweden)

A Jangjoo

2009-01-01

Full Text Available Introduction: Significant perineal injuries and major pelvic fractures resulting from blunt trauma manifest a high-energy injury. Open pelvic fractures (with perineal injury are associated with higher mortality rates of 40 to 60 %. Methods: This study was a review of patients with multiple traumas comprising of major pelvic fracture and severe perineal injuries (Shahid Kamyab hospital in Mashhad from 2002- 2005. A total of 11 patients, with pelvic fracture and perineal injuries (injury to urethra and anal canal were entered in the study. The data was gathered by a checklist and analyzed with SPSS software. Results: The population under study included 11 patients (9 male, 2 female with a mean age of 35years. Cause of trauma in all patients was motor vehicle accidents. All of the patients in the first 6 hours of admission received at least 4 liters of serum ringer lactate and 3 units of packed cells. The mean of packed cell received was 8 units and one patient needed 21 units of packed cells. All of patients were taken to the operating room for diverting colostomy, distal rectal washout, cystostomy and radical debridment and irrigation of devitalized tissue. Good results were achieved in 9 patients and there was one case of mortality and one morbidity (ARF. Conclusion: Open pelvic fractures and perineal injuries are associated with higher mortality rates. Prompt diagnosis and proper treatment (reanimation, colostomy, cystostomy, debridment and irrigation is the key to success.

Les fractures du Talus - a propos de 23 cas | James | Journal de la ...

African Journals Online (AJOL)

Douze patients (52,17%) présentaient des fractures totales classées selon Hawkins. Neuf autres (39,13%) présentaient des fractures parcellaires et deux patients (8,69%) présentaient une fracture séparation du corps. Résultats : Onze des patients présentant une fracture totale ont été traités chirurgicalement avec une ...

Plain film analysis of acetabular fracture

Energy Technology Data Exchange (ETDEWEB)

Kim, Chang Soo; Han, Sang Suk; Yoon, Eu Giene; Cha, Seong Sook; Eun, Tchoong Kie; Chung, Duck Hwan [Inje Medical College Paik Hospital, Pusan (Korea, Republic of)

1986-02-15

Acetabular fracture can result in severe limitation of the motion of the hip joint, which supports total weight of human body. Because of different methods of surgical approach according to fracture type, precise interpretation of X-ray films of acetabular fracture is required. We reviewed 38 cases of simple X-ray films showing acetabular fracture. The results were as follows: 1. Almost 60% of the cases-were in their 2nd and 3rd decades. 2. Twenty cases were male, and 18 cases were female. 3. The most common cause of the injury was traffic accident (33 cases, 86.8%), followed by fall down (4 cases, 10.5%), and slip down (1 case, 2.7%). 4. Elementary fractures were 21 cases (55.3%), and associated fractures were 17 cases (44.7%). 5. Among elementary fractures, posterior wall fractures were 9 cases (23.7%), followed by anterior column fractures (8 cases, 21.1%), anterior wall fractures (4 cases, 10.5%). 6. Among associated fractures, T-shaped fractures were 8 cases (21.1%), followed by both column fractures (6 cases, 15.8%), anterior and hemitransverse fractures (3 cases, 7.8%). 7. Other pelvic bone fractures associated with the acetabular fracture were as follows: fractures of contralateral pubic rami (6 cases, 15.8%) contralateral iliac bone (1 case, 2.6%) and ipsilateral iliac bone (1 case, 2.6%). 8. Injuries of other organs adjacent to the acetabulum were as follows: rupture of the bladder (3 cases, 7.9%), urethra (2 cases, 5.3%) and uterus (1 cases, 2.6%)

Plain film analysis of acetabular fracture

International Nuclear Information System (INIS)

Kim, Chang Soo; Han, Sang Suk; Yoon, Eu Giene; Cha, Seong Sook; Eun, Tchoong Kie; Chung, Duck Hwan

1986-01-01

Acetabular fracture can result in severe limitation of the motion of the hip joint, which supports total weight of human body. Because of different methods of surgical approach according to fracture type, precise interpretation of X-ray films of acetabular fracture is required. We reviewed 38 cases of simple X-ray films showing acetabular fracture. The results were as follows: 1. Almost 60% of the cases-were in their 2nd and 3rd decades. 2. Twenty cases were male, and 18 cases were female. 3. The most common cause of the injury was traffic accident (33 cases, 86.8%), followed by fall down (4 cases, 10.5%), and slip down (1 case, 2.7%). 4. Elementary fractures were 21 cases (55.3%), and associated fractures were 17 cases (44.7%). 5. Among elementary fractures, posterior wall fractures were 9 cases (23.7%), followed by anterior column fractures (8 cases, 21.1%), anterior wall fractures (4 cases, 10.5%). 6. Among associated fractures, T-shaped fractures were 8 cases (21.1%), followed by both column fractures (6 cases, 15.8%), anterior and hemitransverse fractures (3 cases, 7.8%). 7. Other pelvic bone fractures associated with the acetabular fracture were as follows: fractures of contralateral pubic rami (6 cases, 15.8%) contralateral iliac bone (1 case, 2.6%) and ipsilateral iliac bone (1 case, 2.6%). 8. Injuries of other organs adjacent to the acetabulum were as follows: rupture of the bladder (3 cases, 7.9%), urethra (2 cases, 5.3%) and uterus (1 cases, 2.6%).

Trends in the aetiology of facial fractures in the south of Ireland (1975-1993).

LENUS (Irish Health Repository)

Carroll, S M

2012-02-03

An aetiological review of 332 patients with facial fractures seen in a 1 year period (1993) was carried out and compared to a similar study of 266 patients, performed in this unit in 1975. Males predominated in both years. Two thirds of fractures occurred in the second and third decades. Road traffic accident (RTA) related facial fractures decreased from 27% of the total in 1975 to 17% in 1993. Assault related facial fractures increased from 18% of the total in 1975 to 27% in 1993. In both study periods nasal fractures were the most common facial fracture seen and sport was the most common cause of facial fracture. The number of patients undergoing surgery increased from 67% of the total to 79% over the same period.

Machine Learning methods in fitting first-principles total energies for substitutionally disordered solid

Science.gov (United States)

Gao, Qin; Yao, Sanxi; Widom, Michael

2015-03-01

Density functional theory (DFT) provides an accurate and first-principles description of solid structures and total energies. However, it is highly time-consuming to calculate structures with hundreds of atoms in the unit cell and almost not possible to calculate thousands of atoms. We apply and adapt machine learning algorithms, including compressive sensing, support vector regression and artificial neural networks to fit the DFT total energies of substitutionally disordered boron carbide. The nonparametric kernel method is also included in our models. Our fitted total energy model reproduces the DFT energies with prediction error of around 1 meV/atom. The assumptions of these machine learning models and applications of the fitted total energies will also be discussed. Financial support from McWilliams Fellowship and the ONR-MURI under the Grant No. N00014-11-1-0678 is gratefully acknowledged.

The impact of fragility fracture and approaches to osteoporosis risk assessment worldwide.

Science.gov (United States)

Curtis, Elizabeth M; Moon, Rebecca J; Harvey, Nicholas C; Cooper, Cyrus

2017-11-01

Osteoporosis constitutes a major public health problem, through its association with age-related fractures, particularly of the hip, vertebrae, distal forearm and humerus. Substantial geographic variation has been noted in the incidence of osteoporotic fractures worldwide, with Western populations (North America, Europe and Oceania), reporting increases in hip fracture throughout the second half of the 20th century, with a stabilisation or decline in the last two decades. In developing populations however, particularly in Asia, the rates of osteoporotic fracture appears to be increasing. The massive global burden consequent to osteoporosis means that fracture risk assessment should be a high priority among health measures considered by policy makers. The WHO operational definition of osteoporosis, based on a measurement of bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA), has been used globally since the mid-1990s. However, although this definition identifies those at greatest individual risk of fracture, in the population overall a greater total number of fractures occur in individuals with BMD values above the threshold for osteoporosis diagnosis. A number of web-based tools to enable the inclusion of clinical risk factors, with or without BMD, in fracture prediction algorithms have been developed to improve the identification of individuals at high fracture risk, the most commonly used globally being FRAX®. Access to DXA, osteoporosis risk assessment, case finding and treatment varies worldwide, but despite such advances studies indicate that a minority of men and women at high fracture risk receive treatment. Importantly, research is ongoing to demonstrate the clinical efficacy and cost-effectiveness of osteoporosis case finding and risk assessment strategies worldwide. The huge burden caused by osteoporosis related fractures to individuals, healthcare systems and societies should provide a clear impetus for the progression of such

Medical Cost Analysis of the Osteoporotic Hip Fractures

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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.

Evaluation and Management of Proximal Humerus Fractures

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Ekaterina Khmelnitskaya

2012-01-01

Full Text Available Proximal humerus fractures are common injuries, especially among older osteoporotic women. Restoration of function requires a thorough understanding of the neurovascular, musculotendinous, and bony anatomy. This paper addresses the relevant anatomy and highlights various management options, including indication for arthroplasty. In the vast majority of cases, proximal humerus fractures may be treated nonoperatively. In the case of displaced fractures, when surgical intervention may be pursued, numerous constructs have been investigated. Of these, the proximal humerus locking plate is the most widely used. Arthroplasty is generally reserved for comminuted 4-part fractures, head-split fractures, or fractures with significant underlying arthritic changes. Reverse total shoulder arthroplasty is reserved for patients with a deficient rotator cuff, or highly comminuted tuberosities.

Delayed Bleeding and Pelvic Haematoma after Low-Energy Osteoporotic Pubic Rami Fracture in a Warfarin Patient: An Unusual Cause of Abdominal Pain

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Andrea Sandri

2014-01-01

Full Text Available Introduction. Acute abdominal pain may be the presenting symptom in a wide range of diseases in the elderly. Acute abdominal pain related to a delayed bleeding and pelvic haematoma after a low-energy pubic rami fracture is rare and can have important consequences; to the best of our knowledge, only one case has been previously described. Case Report. We present an unusual case of an 83-year-old woman taking warfarin for atrial fibrillation, admitted to the Emergency Department (ED with acute abdominal pain and progressive anemia related to a delayed bleeding and pelvic haematoma 72 hours after a low-energy osteoporotic pubic rami fracture. Warfarin was withheld, anticoagulation was reversed by using fresh frozen plasma and vitamin K, and concentrated red blood cells were given. Haemoglobin level gradually returned to normal with a progressive resorption of the haematoma. Conclusion. Delayed bleeding and pelvic haematoma after osteoporotic pubic rami fracture should be considered in the differential diagnosis of acute abdominal pain in the elderly. This case indicates the need for hospital admission, careful haemodynamic monitoring, and early identification of bleeding in patients with “benign” osteoporotic pubic rami fracture, especially those receiving anticoagulants, to provide an adequate management and prevent severe complications.

Elastic fracture in driven media

International Nuclear Information System (INIS)

Lung Chiwei; Wang Shenggang; Long Qiyi

1999-08-01

Fracture as one of the mechanical properties of materials is structurally dependent. Defects, defect assemblies, grain boundaries and sub-boundaries materials, modify the local stress intensity factors intensively. Brittle fracture prefers to confine to the grain boundary where the specific surface energy is lower than that in the grain. Again, transgranular cracking may occur on the crystal cleavage plane or planes where the local toughness is lowered by dislocation interaction and motion. This paper shows the complexity of the fractal dimension or roughness index of fractured surfaces in materials with metallographic structures or in inhomogeneous media. (author)

[Anatomy of fractures of the inferior scapular angle].

Science.gov (United States)

Bartoníček, J; Tuček, M; Malík, J

2018-01-01

The aim of this study is to describe the anatomy of fractures of the inferior angle and the adjacent part of the scapular body, based on 3D CT reconstructions. In a series of 375 scapular fractures, we identified a total of 20 fractures of the inferior angle of the scapular body (13 men, 7 women), with a mean patient age of 50 years (range 3373). In all fractures, 3D CT reconstructions were obtained, allowing an objective evaluation of the fracture pattern with a focus on the size and shape of the inferior angle fragment, propagation of the fracture line to the lateral and medial borders of the infraspinous part of the scapular body, fragment displacement and any additional fracture of the ipsilateral scapula and the shoulder girdle. We identified a total of 5 types of fracture involving the distal half of the infraspinous part of the scapular body. The first type, recorded in 5 cases, affected only the apex of the inferior angle, with a small part of the adjacent medial border. The second type, occurring in 4 cases, involved fractures separating the entire inferior angle. The third type, represented by 4 cases, was characterized by a fracture line starting medially close above the inferior angle and passing proximolaterally. The separated fragment had a shape of a big drop, carrying also the distal half of the lateral pillar in addition to the inferior angle. In the fourth type identified in 5 fractures, the separated fragment was formed both by the inferior angle and a variable part of the medial border. The fifth type, being by its nature a transition to the fracture of the infraspinous part of the body, was recorded in 2 cases, with the same V-shaped fragment. Fractures of the inferior angle and the adjacent part of the scapular body are groups of fractures differing from other infraspinous fractures of the scapular body. Although these fractures are highly variable in terms of shape, they have the same course of fracture line and the manner of displacement

Fracture risk in hepatitis C virus infected persons: results from the DANVIR cohort study.

Science.gov (United States)

Hansen, Ann-Brit Eg; Omland, Lars Haukali; Krarup, Henrik; Obel, Niels

2014-07-01

The association between Hepatitis C virus (HCV)-infection and fracture risk is not well characterized. We compared fracture risk between HCV-seropositive (HCV-exposed) patients and the general population and between patients with cleared and chronic HCV-infection. Outcome measures were time to first fracture at any site, time to first low-energy and first non-low-energy (other) fracture in 12,013 HCV-exposed patients from the DANVIR cohort compared with a general population control cohort (n=60,065) matched by sex and age. Within DANVIR, 4500 patients with chronic HCV-infection and 2656 patients with cleared HCV-infection were studied. Compared with population controls, HCV-exposed patients had increased overall risk of fracture [adjusted incidence rate ratio (aIRR) 2.15, 95% Confidence Interval (CI) 2.03-2.28], increased risk of low-energy fracture (aIRR 2.13, 95% CI: 1.93-2.35) and of other fracture (aIRR 2.18, 95% CI: 2.02-2.34). Compared with cleared HCV-infection, chronic HCV-infection was not associated with increased risk of fracture at any site (aIRR 1.08, 95% CI: 0.97-1.20), or other fracture (aIRR 1.04, 95% CI: 0.91-1.19). The aIRR for low-energy fracture was 1.20 (95% CI: 0.99-1.44). HCV-exposed patients had increased risk of all fracture types. In contrast, overall risk of fracture did not differ between patients with chronic vs. cleared HCV-infection, although chronic HCV-infection might be associated with a small excess risk of low-energy fractures. Our study suggests that fracture risk in HCV-infected patients is multi-factorial and mainly determined by lifestyle-related factors associated with HCV-exposure. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

How fast is the growth of Total Cross Section at High Energies?

CERN Document Server

Fazal-e-Aleem, M; Sohail-Afzal, Tahir; Ayub-Faridi, M; Qadee-Afzal, M

2003-01-01

Relativistic Heavy Ion Collider and Large Hadron Colliders have special agenda for the measurements of the total cross sections at high energies giving us an opportunity to touch cosmic ray energies. Recent analyses of the cosmic ray data together with earlier experimental measurements at ISR and SPS gives us an insight about the behaviour of this important parameter at asymptotic energies. We will study the growth of total cross section at high energies in the light of various theoretical approaches with special reference to measurements at RHIC and LHC.

Ecological total-factor energy efficiency of regions in China

International Nuclear Information System (INIS)

Li Lanbing; Hu Jinli

2012-01-01

Most existing energy efficiency indices are computed without taking into account undesirable outputs such as CO 2 and SO 2 emissions. This paper computes the ecological total-factor energy efficiency (ETFEE) of 30 regions in China for the period 2005–2009 through the slack-based model (SBM) with undesirable outputs. We calculate the ETFEE index by comparing the target energy input obtained from SBM with undesirable outputs to the actual energy input. Findings show that China's regional ETFEE still remains a low level of around 0.600 and regional energy efficiency is overestimated by more than 0.100 when not looking at environmental impacts. China's regional energy efficiency is extremely unbalanced: the east area ranks first with the highest ETFEE of above 0.700, the northeast and central areas follow, and the west area has the lowest ETFEE of less than 0.500. A monotone increasing relation exists between the area's ETFEE and China's per capita GDP. The truncated regression model shows that the ratio of R and D expenditure to GDP and the degree of foreign dependence have positive impacts, whereas the ratio of the secondary industry to GDP and the ratio of government subsidies for industrial pollution treatment to GDP have negative effects, on the ETFEE. - Highlights: ► Most energy efficiency indices ignore undesirable outputs such as CO 2 and SO 2 emissions. ► The ecological total-factor energy efficiency (ETFEE) is computed by slack-based model (SBM). ► The datasets contains 30 regions in China for the period 2005–2009. ► China's regional energy efficiency is extremely unbalanced. ► A monotone increasing relation exists between ETFEE and per capita GDP.

Experimental Study On Fracture Property Of Double Cantilever Beam Specimen With Aluminum Foam

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Kim Y.C.

2015-06-01

Full Text Available This study aims to investigate double cantilever beam specimen with aluminum foam bonded by spray adhesive to investigate the fracture strength of the adhesive joint experimentally. The fracture energy at opening mode is calculated by the formulae of British Engineering Standard (BS 7991 and International Standard (ISO 11343. For the static experiment, four types of specimens with the heights (h of 25 mm, 30 mm, 35 mm and 40 mm are manufactured and the experimental results are compared with each other. As the height becomes greater, the fracture energy becomes higher. After the length of crack reaches 150 mm, the fracture energy of the specimen (h=35 mm is greater than that of the specimen (h=40 mm. Fatigue test is also performed with DCB test specimen. As the height decreases, the fracture energy becomes higher. By the result obtained from this study, aluminum foam with adhesive joint can be applied to actual composite structure and its fracture property can possibly be anticipated.

Economic analysis model for total energy and economic systems

International Nuclear Information System (INIS)

Shoji, Katsuhiko; Yasukawa, Shigeru; Sato, Osamu

1980-09-01

This report describes framing an economic analysis model developed as a tool of total energy systems. To prospect and analyze future energy systems, it is important to analyze the relation between energy system and economic structure. We prepared an economic analysis model which was suited for this purpose. Our model marks that we can analyze in more detail energy related matters than other economic ones, and can forecast long-term economic progress rather than short-term economic fluctuation. From view point of economics, our model is longterm multi-sectoral economic analysis model of open Leontief type. Our model gave us appropriate results for fitting test and forecasting estimation. (author)

Hip fracture in hospitalized medical patients

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Zapatero Antonio

2013-01-01

Full Text Available Abstract Background The aim of the present study is to analyze the incidence of hip fracture as a complication of admissions to internal medicine units in Spain. Methods We analyzed the clinical data of 2,134,363 adults who had been admitted to internal medicine wards. The main outcome was a diagnosis of hip fracture during hospitalization. Outcome measures included rates of in-hospital fractures, length of stay and cost. Results A total of 1127 (0.057% admittances were coded with an in-hospital hip fracture. In hospital mortality rate was 27.9% vs 9.4%; p  Conclusions In-hospital hip fracture notably increased mortality during hospitalization, doubling the mean length of stay and mean cost of admission. These are reasons enough to stress the importance of designing and applying multidisciplinary plans focused on reducing the incidence of hip fractures in hospitalized patients.

Craniomaxillofacial fractures during recreational baseball and softball.

Science.gov (United States)

Bak, Matthew J; Doerr, Timothy D

2004-10-01

Baseball and softball are leading causes of sports-related facial trauma in the United States. We review our institutional experience (Strong Memorial Hospital, Rochester, NY) with these injuries and discuss measures to reduce their incidence. We review our institutions experience with facial fractures sustained during the course of a softball or baseball game over a 12-year period. A total of 38 patients were identified and medical records analyzed for patient demographics, type of impact, and fracture location. The male-to-female ratio was 3.2:1; mean age was 24.2 years, with 17 (45%) of the injuries occurring in the pediatric population. The majority of the injuries were caused by direct impact with the ball (68%), while player-player collisions (18%) and impact from a swung bat (13%) were responsible for the remaining injuries. There were a total of 39 fractures; 18 fractures (46%) involved the midface (level 2), skull (level 1) fractures accounted for 12 (31%), while 9 (23%) were mandibular (level 3) fractures. With 68% of the injuries resulting from a ball impact, we endorse the recommendations of the Consumer Product Safety Commission for the use of low-impact National Operating Committee on Standards for Athletic Equipment-approved baseballs and softballs for youth and recreational leagues.

Relationships between metacarpal morphometry, fore-arm and vertebral bone density and fractures in post-menopausal women

International Nuclear Information System (INIS)

Wishart, J.M.; Horowitz, M.; Bochner, M.; Need, A.G.; Nordin, B.E.C.

1993-01-01

The relationships between metacarpal morphometric, vertebral and forearm density measurement and the prevalence of vertebral and peripheral fractures were examined in 239 postmenopausal women (median age 63, range 32-84 years). Metacarpal cortical area/total area ratio (CA/TA) was measured with needle calipers forearm mineral density (FMD) by single photon absorptiometry and vertebral mineral density (VMD) by single energy quantitative computed tomography. The authors suggest that metacarpal morphometry, which is widely available at relatively low cost, yields cross-sectional information about bone density and fracture risk, comparable with that obtained by forearm and vertebral densitometry. (Author)

Hip fracture in hospitalized medical patients

OpenAIRE

Zapatero Antonio; Barba Raquel; Canora Jesús; Losa Juan E; Plaza Susana; San Roman Jesús; Marco Javier

2013-01-01

Abstract Background The aim of the present study is to analyze the incidence of hip fracture as a complication of admissions to internal medicine units in Spain. Methods We analyzed the clinical data of 2,134,363 adults who had been admitted to internal medicine wards. The main outcome was a diagnosis of hip fracture during hospitalization. Outcome measures included rates of in-hospital fractures, length of stay and cost. Results A total of 1127 (0.057%) admittances were coded with an in-hosp...

Improving Fracture Toughness of Epoxy Nanocomposites by Silica Nanoparticles

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Seyed Reza Akherati Sany

2017-04-01

Full Text Available An epoxy resin was modified by silica nanoparticles and cured with an anhydride. The particles with different batches of 12, 20, and 40 nm sizes were each distributed into the epoxy resin ultrasonically. Electron microscopy images showed that the silica particles were well dispersed throughout the resin. Tensile test results showed that Young’s modulus and tensile strength increased with the volume fraction and surface area of the silica particles. The simultaneous use of two average sizes of 20 and 40 nm diameter silica particles still increased these mechanical properties but other combinations of silica particles were unsuccessful. A three-point bending test on each pre-cracked specimen was performed to measure the mode I fracture toughness energy. The fracture energy increased from 283 J/m2 for the unmodified epoxy to about 740 J/m2 for the epoxy with 4.5 wt% of 12 nm diameter silica nanoparticles. The fracture energy of smaller particles was greater because of their higher surface to volume ratio. The fracture energy results showed also that the combined nanoparticles has a synergic effect on the fracture toughness of nanocomposites. Simultaneous use of 10 and 20 nm particles increased the fracture energy to about 770 J/m2. Finally, crack-opening displacement was calculated and found to be in the range of several micrometers which was much larger than the sizes of particles studied. Thus, the toughening mechanisms of crack pinning and crack deflection have a negligible effect on improvement of toughness, nevertheless, the plastic deformation and plastic void growth are dominant mechanisms in epoxy toughening by nanoparticles.

A multi-scale experimental and simulation approach for fractured subsurface systems

Science.gov (United States)

Viswanathan, H. S.; Carey, J. W.; Frash, L.; Karra, S.; Hyman, J.; Kang, Q.; Rougier, E.; Srinivasan, G.

2017-12-01

Fractured systems play an important role in numerous subsurface applications including hydraulic fracturing, carbon sequestration, geothermal energy and underground nuclear test detection. Fractures that range in scale from microns to meters and their structure control the behavior of these systems which provide over 85% of our energy and 50% of US drinking water. Determining the key mechanisms in subsurface fractured systems has been impeded due to the lack of sophisticated experimental methods to measure fracture aperture and connectivity, multiphase permeability, and chemical exchange capacities at the high temperature, pressure, and stresses present in the subsurface. In this study, we developed and use microfluidic and triaxial core flood experiments required to reveal the fundamental dynamics of fracture-fluid interactions. In addition we have developed high fidelity fracture propagation and discrete fracture network flow models to simulate these fractured systems. We also have developed reduced order models of these fracture simulators in order to conduct uncertainty quantification for these systems. We demonstrate an integrated experimental/modeling approach that allows for a comprehensive characterization of fractured systems and develop models that can be used to optimize the reservoir operating conditions over a range of subsurface conditions.

DUAL-ENERGY X-RAY ABSORPTIOMETRY AND CALCULATED FRAX RISK SCORES MAY UNDERESTIMATE OSTEOPOROTIC FRACTURE RISK IN VITAMIN D-DEFICIENT VETERANS WITH HIV INFECTION.

Science.gov (United States)

Stephens, Kelly I; Rubinsztain, Leon; Payan, John; Rentsch, Chris; Rimland, David; Tangpricha, Vin

2016-04-01

We evaluated the utility of the World Health Organization (WHO) Fracture Risk Assessment Tool (FRAX) in assessing fracture risk in patients with human immunodeficiency virus (HIV) and vitamin D deficiency. This was a retrospective study of HIV-infected patients with co-existing vitamin D deficiency at the Atlanta Veterans Affairs Medical Center. Bone mineral density (BMD) was assessed by dual-energy X-ray absorptiometry (DEXA), and the 10-year fracture risk was calculated by the WHO FRAX algorithm. Two independent radiologists reviewed lateral chest radiographs for the presence of subclinical vertebral fractures. We identified 232 patients with HIV and vitamin D deficiency. Overall, 15.5% of patients met diagnostic criteria for osteoporosis on DEXA, and 58% had low BMD (T-score between -1 and -2.5). The median risk of any major osteoporotic and hip fracture by FRAX score was 1.45 and 0.10%, respectively. Subclinical vertebral fractures were detected in 46.6% of patients. Compared to those without fractures, those with fractures had similar prevalence of osteoporosis (15.3% versus 15.7%; P>.999), low BMD (53.2% versus 59.3%; P = .419), and similar FRAX hip scores (0.10% versus 0.10%; P = .412). While the FRAX major score was lower in the nonfracture group versus fracture group (1.30% versus 1.60%; P = .025), this was not clinically significant. We found a high prevalence of subclinical vertebral fractures among vitamin D-deficient HIV patients; however, DEXA and FRAX failed to predict those with fractures. Our results suggest that traditional screening tools for fragility fractures may not be applicable to this high-risk patient population.

Ductile fracture theories for pressurised pipes and containers

Science.gov (United States)

Erdogan, F.

1976-01-01

Two mechanisms of fracture are distinguished. Plane strain fractures occur in materials which do not undergo large-scale plastic deformations prior to and during a possible fracture deformation. Plane stress or high energy fractures are generally accompanied by large inelastic deformations. Theories for analyzing plane stress are based on the concepts of critical crack opening stretch, K(R) characterization, J-integral, and plastic instability. This last is considered in some detail. The ductile fracture process involves fracture initiation followed by a stable crack growth and the onset of unstable fracture propagation. The ductile fracture propagation process may be characterized by either a multiparameter (discrete) model, or some type of a resistance curve which may be considered as a continuous model expressed graphically. These models are studied and an alternative model is also proposed for ductile fractures which cannot be modeled as progressive crack growth phenomena.

Effective management of bone fractures with the IlluminOss® photodynamic bone stabilization system: initial clinical experience from the European Union registry

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Thomas Gausepohl

2017-02-01

Full Text Available The IlluminOss® system (IS uses a light-curable polymer contained within an inflatable balloon catheter, forming a patient customized intramedullary implant. A registry was established in Germany and The Netherlands to prospectively collect technical and clinical outcomes in patients treated with IS for fractures of the phalange, metacarpal, radius, ulna, distal radius, fibula, clavicle and/or olecranon. Humeral, femoral, tibial and pelvic fractures were included under compassionate use. Procedural success included successful placement of the device at the target fracture site and achievement of fracture stabilization. Clinical and radiographic assessments were made postoperatively through 12 months. One hundred thirty two patients (149 fractures were enrolled with most fractures (85% resulting from low-energy trauma. Simple fractures predominated (47% followed by complex (23% and wedge (16% fractures. Procedural success was achieved in all patients and no implants required removal or revision. Normal range of motion was realized in 87% of fractures. Radiographically, there was substantial cortical bridging, total dissolution of the fracture line, and complete fracture healing. Across a variety of fracture types, the IS provides a safe and effective approach for rapid healing and functional recovery.

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.

Carotenoids and risk of fracture: a meta-analysis of observational studies.

Science.gov (United States)

Xu, Jiuhong; Song, Chunli; Song, Xiaochao; Zhang, Xi; Li, Xinli

2017-01-10

To quantify the association between dietary and circulating carotenoids and fracture risk, a meta-analysis was conducted by searching MEDLINE and EMBASE databases for eligible articles published before May 2016. Five prospective and 2 case-control studies with 140,265 participants and 4,324 cases were identified in our meta-analysis. Among which 5 studies assessed the association between dietary carotenoids levels and hip fracture risk, 2 studies focused on the association between circulating carotenoids levels and any fracture risk. A random-effects model was employed to summarize the risk estimations and their 95% confidence intervals (CIs). Hip fracture risk among participants with high dietary total carotenoids intake was 28% lower than that in participants with low dietary total carotenoids (OR: 0.72; 95% CI: 0.51, 1.01). A similar risk of hip fracture was found for β-carotene based on 5 studies, the summarized OR for high vs. low dietary β-carotene was 0.72 (95% CI: 0.54, 0.95). However, a significant between-study heterogeneity was found (total carotene: I2 = 59.4%, P = 0.06; β-carotene: I2 = 74.4%, P = 0.04). Other individual carotenoids did not show significant associations with hip fracture risk. Circulating carotene levels had no significant association with any fracture risk, the pooled OR (95% CI) was 0.83 (0.59, 1.17). Based on the evidence from observational studies, our meta-analysis supported the hypothesis that higher dietary total carotenoids or β-carotene intake might be potentially associated with a low risk of hip fracture, however, future well-designed prospective cohort studies and randomized controlled trials are warranted to specify the associations between carotenoids and fracture.

Flow and transport in hierarchically fractured systems

International Nuclear Information System (INIS)

Karasaki, K.

1993-01-01

Preliminary results indicate that flow in the saturated zone at Yucca Mountain is controlled by fractures. A current conceptual model assumes that the flow in the fracture system can be approximately by a three-dimensionally interconnected network of linear conduits. The overall flow system of rocks at Yucca Mountain is considered to consist of hierarchically structured heterogeneous fracture systems of multiple scales. A case study suggests that it is more appropriate to use the flow parameters of the large fracture system for predicting the first arrival time, rather than using the bulk average parameters of the total system

Thermodynamics of the living organisms. Allometric relationship between the total metabolic energy, chemical energy and body temperature in mammals

Science.gov (United States)

Atanasov, Atanas Todorov

2017-11-01

The study present relationship between the total metabolic energy (ETME(c), J) derived as a function of body chemical energy (Gchem, J) and absolute temperature (Tb, K) in mammals: ETME(c) =Gchem (Tb/Tn). In formula the temperature Tn =2.73K appears normalization temperature. The calculated total metabolic energy ETME(c) differs negligible from the total metabolic energy ETME(J), received as a product between the basal metabolic rate (Pm, J/s) and the lifespan (Tls, s) of mammals: ETME = Pm×Tls. The physical nature and biological mean of the normalization temperature (Tn, K) is unclear. It is made the hypothesis that the kTn energy (where k= 1.3806×10-23 J/K -Boltzmann constant) presents energy of excitation states (modes) in biomolecules and body structures that could be in equilibrium with chemical energy accumulated in body. This means that the accumulated chemical energy allows trough all body molecules and structures to propagate excitations states with kTn energy with wavelength in the rage of width of biological membranes. The accumulated in biomolecules chemical energy maintains spread of the excited states through biomolecules without loss of energy.

Investigations into the influence of the tup velocity and the heat treatment on the dynamic fracture toughness of Inconel 625

International Nuclear Information System (INIS)

Krompholz, K.; Tipping, P.; Ullrich, G.

1983-09-01

Experiments were performed with an instrumented impact machine using different drop heights, on the nickel base alloy Inconel 625 in the as received state and after heat treatment for about 1000 h at 923 K. The absorbed impact energy can be obtained either by the direct dial reading, by the integration of the load versus load point displacement diagram or by the integration of the load versus time diagram, knowing the initial impact velocity of the tup. In all cases the agreement was excellent. It is shown that, (i) the dynamic fracture toughness is dependent on the tup velocity and as a consequence on the total energy of the hammer at the different drop heights; (ii) the embrittlement during heat treatment is not combined with a decrease in the fracture toughness although a strong decrease in the absorbed impact energy is observed; (iii) defining a dynamic stress from the velocity dependence of the fracture toughness, the stress is higher for the embrittled material - a tendency verified by tensile tests; (iv) the dynamic fracture toughness can be correlated with the absorbed impact energy up to the load maximum for the heat treated material while the as received material exhibits no such dependency. The change in the tup velocity during the impact process is only small for this type of material. (Auth.)

Risk of low-energy hip, wrist, and upper arm fractures among current and previous users of hormone replacement therapy

DEFF Research Database (Denmark)

Hundrup, Yrsa Andersen; Høidrup, Susanne; Ekholm, Ola

2004-01-01

To examine the effect of oestrogen alone and in combination with progestin on the risk of low-energy, hip, wrist, and upper arm fractures. Additionally, to examine to what extent previous use, duration of use as well as recency of discontinuation of hormone replacement therapy (HRT) influences...

Effect of temperature and moisture on the fracture energy and the thermal properties of concrete

International Nuclear Information System (INIS)

Kallel, H.; Carre, H.; Laborderie, C.; Masson, B.; Tran, N.C.

2015-01-01

In nuclear power plants, during a severe accident the containment building undergoes an increase of pressure, temperature and relative humidity that can reach respectively 5 bars, 140 C. degrees and the saturation of water vapor. Beyond the regulatory calculations, a suitable knowledge of the thermal and mechanical behaviour of the materials and more specifically of the concrete is required to carry out accurate numerical simulations. An experimental apparatus has been designed to assess the fracture energy (G f ) evolutions for concrete under various experimental conditions in terms of temperature and relative humidity of the concrete. Mechanical tests have been performed under different controlled conditions in terms of temperature (T=30 C. degrees ) and liquid water degree of saturation S w (four target values of 50, 70, 90 and 100%). These values of liquid water degree of saturation have been obtained by conditioning the relative humidity of the sealed environment where specimens have been left for the equalisation process by using potassium salt solutions. DCT (Disk-shape Compact Tension) test has been chosen for determining G f . In comparison with three points bending test, the typology of the test, the equipment and all test devices have been validated. Test results show clearly the decreasing of the fracture energy as saturation degree increases. This evolution has a linear trend for S w ranging from 36 % to 97 %

Possible factors for ankle fractures

Directory of Open Access Journals (Sweden)

Tabaković Dejan

2010-01-01

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

Novel classification system of rib fractures observed in infants.

Science.gov (United States)

Love, Jennifer C; Derrick, Sharon M; Wiersema, Jason M; Pinto, Deborrah C; Greeley, Christopher; Donaruma-Kwoh, Marcella; Bista, Bibek

2013-03-01

Rib fractures are considered highly suspicious for nonaccidental injury in the pediatric clinical literature; however, a rib fracture classification system has not been developed. As an aid and impetus for rib fracture research, we developed a concise schema for classifying rib fracture types and fracture location that is applicable to infants. The system defined four fracture types (sternal end, buckle, transverse, and oblique) and four regions of the rib (posterior, posterolateral, anterolateral, and anterior). It was applied to all rib fractures observed during 85 consecutive infant autopsies. Rib fractures were found in 24 (28%) of the cases. A total of 158 rib fractures were identified. The proposed schema was adequate to classify 153 (97%) of the observed fractures. The results indicate that the classification system is sufficiently robust to classify rib fractures typically observed in infants and should be used by researchers investigating infant rib fractures. © 2013 American Academy of Forensic Sciences.

Maxillofacial fracture experiences: a review of 152 cases.

Science.gov (United States)

Aydin, Osman Enver; Tan, Onder; Algan, Said; Kuduban, Selma Denktas; Barin, Ensar Zafer; Cinal, Hakan; Sarici, Murat; Avsar, Umit

2012-12-01

The fractures of facial structures lead to great morbidity. Cross-sectional studies are needed to evaluate the current state of maxillofacial traumas. Thus, this study aims to evaluate these experiences and to compare these results with the current literature. The medical records of the maxillofacial fracture cases hospitalized between January 2004 and November 2011 were examined. The age, sex, etiology, fracture localization and treatment method for each case were documented. The affected facial bones were grouped as mandible, maxilla, zygoma, naso-orbitoethmoid complex (NOEC) and blow-out. Nasal fractures were excluded. The cases were assigned to 3 groups with respect to age (below 16, above 65 and between 17 and 64). The chi Square test was used to assess the significance of the difference in mandibular fracture rates in the pediatric population compared to others. The total number of cases was 152. The total number of fractures was 185. Of the 152 cases, 117 were male and 35 were female. The average age was 31.4 (±18.3), ranging between 2 and 81. Thirty-one cases were 16 years old or less. Nine cases were 65 years old or more. Mandibular and zygomatic fractures were the most prevalent fractures in the adult group. Mandibular fractures were significantly more common in the pediatric age group compared to rest of the population (X(2), pOpen reduction and internal fixation was the most frequently conducted treatment modality in all age groups. Retrospective studies are important for the projection of future prospects. In summary, our results indicate that pediatric fractures are mostly in the lower face and usually affect the condylar region, which is consistent with the literature.

Association of stressful life events with incident falls and fractures in older men: the Osteoporotic Fractures in Men (MrOS) Study

Science.gov (United States)

Fink, Howard A.; Kuskowski, Michael A.; Marshall, Lynn M.

2014-01-01

Background: small, retrospective studies suggest that major life events and/or sudden emotional stress may increase fall and fracture risk. The current study examines these associations prospectively. Methods: a total of 5,152 men aged ≥65 years in the Osteoporotic Fractures in Men study self-reported data on stressful life events for 1 year prior to study Visit 2. Incident falls and fractures were ascertained for 1 year after Visit 2. Fractures were centrally confirmed. Results: a total of 2,932 (56.9%) men reported ≥1 type of stressful life event. In men with complete stressful life event, fall and covariate data (n = 3,949), any stressful life event was associated with a 33% increased risk of incident fall [relative risk (RR) 1.33, 95% confidence interval (CI) 1.19–1.49] and 68% increased risk of multiple falls (RR = 1.68, 95% CI = 1.40–2.01) in the year following Visit 2 after adjustment for age, education, Parkinson's disease, diabetes, stroke, instrumental activities of daily living (IADL) impairment, chair stand time, walk speed, multiple past falls, depressive symptoms and antidepressant use. Risk increased with the number of types of stressful life events. Though any stressful life event was associated with a 58% increased age-adjusted risk for incident fracture, this association was attenuated and no longer statistically significant after additional adjustment for total hip bone mineral density, fracture after age 50, Parkinson's disease, stroke and IADL impairment. Conclusions: in this cohort of older men, stressful life events significantly increased risk of incident falls independent of other explanatory variables, but did not independently increase incident fracture risk. PMID:24002237

[Trochanteric femoral fractures].

Science.gov (United States)

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

2013-01-01

, 31-A2) and intertrochanteric (31-A3) fractures is considered an important approach because of their different behaviour at reduction. Pertrochanteric fractures occurred more frequently (81.5%); the patients' age was higher (80 years on the average) and women outnumbered men at a ratio of 3:1. Intertrochanteric fractures were found in significantly younger patients (average, 72 years), with a women-to-men ratio of 1.3:1. Stable pertrochanteric fractures (31-A1) were preferably indicated for DHS surgery. Unstable pertrochanteric (31-A2) and intertrochanteric (31- A3) fractures were treated with a nail. The patients underwent surgery on the day of injury or the next day. In the case of contraindications to an urgent intervention, surgery was performed after the patient's medical condition had stabilised. The number of complications was largely related to technical errors, such as insufficient reduction or an incorrectly inserted implant. Intertrochanteric fractures were associated with a higher occurrence of complications. No implant can compensate for errors due to surgery. Serious complications can be reduced by the correct assessment of fracture type, the use of an appropriate operative technique and early treatment of potential complications. The necessity of restoring continuity in the medial cortex of the femoral neck (Adams' arch) is the requirement that should be observed. Pseudoarthrosis or varus malalignment in a healed hip should be managed by valgus osteotomy. When the femoral head or the acetabulum is damaged, total hip arthroplasty is indicated. A prerequisite for successful surgical outcome is urgently and correctly performed osteosynthesis allowing for early rehabilitation and mobilisation of the patient.

Environment-adjusted total-factor energy efficiency of Taiwan's service sectors

International Nuclear Information System (INIS)

Fang, Chin-Yi; Hu, Jin-Li; Lou, Tze-Kai

2013-01-01

This study computes the pure technical efficiency (PTE) and energy-saving target of Taiwan's service sectors during 2001–2008 by using the input-oriented data envelopment analysis (DEA) approach with the assumption of a variable returns-to-scale (VRS) situation. This paper further investigates the effects of industry characteristics on the energy-saving target by applying the four-stage DEA proposed by Fried et al. (1999). We also calculate the pre-adjusted and environment-adjusted total-factor energy efficiency (TFEE) scores in these service sectors. There are three inputs (labor, capital stock, and energy consumption) and a single output (real GDP) in the DEA model. The most energy efficient service sector is finance, insurance and real estate, which has an average TFEE of 0.994 and an environment-adjusted TFEE (EATFEE) of 0.807. The study utilizes the panel-data, random-effects Tobit regression model with the energy-saving target (EST) as the dependent variable. Those service industries with a larger GDP output have greater excess use of energy. The capital–labor ratio has a significantly positive effect while the time trend variable has a significantly negative impact on the EST, suggesting that future new capital investment should also be accompanied with energy-saving technology in the service sectors. - Highlights: • The technical efficiency and energy-saving target of service sectors are assessed. • The pre-adjusted and environment-adjusted total-factor energy efficiency scores in services are assessed. • The industrial characteristic differences are examined by the panel-data, random-effects Tobit regression model. • Labor, capital, and energy and an output (GDP) are included in the DEA model. • Future new capital investment should also be accompanied with energy-saving technology in the service sectors

A simple fracture energy prediction method for fiber network based on its morphological features extracted by X-ray tomography

International Nuclear Information System (INIS)

Huang, Xiang; Wang, Qinghui; Zhou, Wei; Li, Jingrong

2013-01-01

The fracture behavior of a novel porous metal fiber sintered sheet (PMFSS) was predicted using a semi-empirical method combining the knowledge of its morphological characteristics and micro-mechanical responses. The morphological characteristics were systematically summarized based on the analysis of the topologically identical skeleton representation extracted from the X-ray tomography images. The analytical model firstly proposed by Tan et al. [1] was further modified according to the experimental observations from both tensile tests of single fibers and sintered fiber sheets, which built the coupling of single fiber segment and fiber network in terms of fracture energy using a simple prediction method. The efficacy of the prediction model was verified by comparing the predicted results to the experimental measurements. The prediction error that arose at high porosity was analyzed through fiber orientation distribution. Moreover, the tensile fracture process evolving from single fiber segments at micro-scale to the global mechanical performance was investigated

Fluid transport in reaction induced fractures

Science.gov (United States)

Ulven, Ole Ivar; Sun, WaiChing; Malthe-Sørenssen, Anders

2015-04-01

The process of fracture formation due to a volume increasing chemical reaction has been studied in a variety of different settings, e.g. weathering of dolerites by Røyne et al. te{royne}, serpentinization and carbonation of peridotite by Rudge et al. te{rudge} and replacement reactions in silica-poor igneous rocks by Jamtveit et al. te{jamtveit}. It is generally assumed that fracture formation will increase the net permeability of the rock, and thus increase the reactant transport rate and subsequently the total rate of material conversion, as summarised by Kelemen et al. te{kelemen}. Ulven et al. te{ulven_1} have shown that for fluid-mediated processes the ratio between chemical reaction rate and fluid transport rate in bulk rock controls the fracture pattern formed, and Ulven et al. te{ulven_2} have shown that instantaneous fluid transport in fractures lead to a significant increase in the total rate of the volume expanding process. However, instantaneous fluid transport in fractures is clearly an overestimate, and achievable fluid transport rates in fractures have apparently not been studied in any detail. Fractures cutting through an entire domain might experience relatively fast advective reactant transport, whereas dead-end fractures will be limited to diffusion of reactants in the fluid, internal fluid mixing in the fracture or capillary flow into newly formed fractures. Understanding the feedback process between fracture formation and permeability changes is essential in assessing industrial scale CO2 sequestration in ultramafic rock, but little is seemingly known about how large the permeability change will be in reaction-induced fracturing. In this work, we study the feedback between fracture formation during volume expansion and fluid transport in different fracture settings. We combine a discrete element model (DEM) describing a volume expanding process and the related fracture formation with different models that describe the fluid transport in the

Percutaneous Vertebroplasty for Osteoporotic Compression Fracture: Multivariate Study of Predictors of New Vertebral Body Fracture

International Nuclear Information System (INIS)

Komemushi, Atsushi; Tanigawa, Noboru; Kariya, Shuji; Kojima, Hiroyuki; Shomura, Yuzo; Komemushi, Sadao; Sawada, Satoshi

2006-01-01

Purpose. To investigate the risk factors and relative risk of new compression fractures following vertebroplasty. Methods. Initially, we enrolled 104 consecutive patients with vertebral compression fractures caused by osteoporosis. A total of 83 of the 104 patients visited our hospital for follow-up examinations for more than 4 weeks after vertebroplasty. Logistic regression analysis of the data obtained from these 83 patients was used to determine relative risks of recurrent compression fractures, using 13 different factors. Results. We identified 59 new fractures in 30 of the 83 patients: 41 new fractures in vertebrae adjacent to treated vertebrae; and 18 new fractures in vertebrae not adjacent to treated vertebrae. New fractures occurred in vertebrae adjacent to treated vertebrae significantly more frequently than in vertebrae not adjacent to treated vertebrae. Only cement leakage into the disk was a significant predictor of new vertebral body fracture after vertebroplasty (odds ratio = 4.633). None of the following covariates were associated with increased risk of new fracture: age, gender, bone mineral density, the number of vertebroplasty procedures, the number of vertebrae treated per procedure, the cumulative number of vertebrae treated, the presence of a single untreated vertebra between treated vertebrae, the presence of multiple untreated vertebrae between treated vertebrae, the amount of bone cement injected per procedure, the cumulative amount of bone cement injected, cement leakage into the soft tissue around the vertebra, and cement leakage into the vein

Cleavage and creep fracture of rock salt

International Nuclear Information System (INIS)

Chan, K.S.; Munson, D.E.; Bodner, S.R.

1996-01-01

The dominant failure mechanism in rock salt at ambient temperature is either cleavage or creep fracture. Since the transition of creep fracture to cleavage in a compressive stress field is not well understood, failure of rock salt by cleavage and creep fracture is analyzed in this paper to elucidate the effect of stress state on the competition between these two fracture mechanisms. For cleavage fracture, a shear crack is assumed to cause the formation and growth of a symmetric pair of wing cracks in a predominantly compressive stress field. The conditions for wing-crack instability are derived and presented as the cleavage fracture boundary in the fracture mechanism map. Using an existing creep fracture model, stress conditions for the onset of creep fracture and isochronous failure curves of specified times-to-rupture are calculated and incorporated into the fracture mechanism map. The regimes of dominance by cleavage and creep fracture are established and compared with experimental data. The result indicates that unstable propagation of cleavage cracks occurs only in the presence of tensile stress. The onset of creep fracture is promoted by a tensile stress, but can be totally suppressed by a high confining pressure. Transition of creep fracture to cleavage occurs when critical conditions of stress difference and tensile stress for crack instability are exceeded

Total Corporate social responsibility report 2004. Sharing our energy; TOTAL rapport societal and environnemental 2004. Notre energie en partage

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-05-15

This document presents the social and environmental activities of the group Total for the year 2004. It provides information on the ethical aspects of the governance, the industrial security, the environmental policy, the public health and the occupational safety, the social liability and the economical and social impact of the group activities in the local development, the contribution to the climatic change fight and the development of other energy sources. (A.L.B.)

Parameterization of α-nucleus total reaction cross section at intermediate energies

International Nuclear Information System (INIS)

Alvi, M A; Abdulmomen, M A

2008-01-01

Applying a Coulomb correction factor to the Glauber model we have derived a closed expression for α-nucleus total reaction cross section, σ R . Under the approximation of rigid projectile model, the elastic S-matrix element S el (b) is evaluated from the phenomenological N-α amplitude and a Gaussian fit to the Helm's model form factor. Excellent agreements with the experimental data have been achieved by performing two-parameter fits to the α-nucleus σ R data in the energy range about 75 to 193 MeV. One of the parameters was found to be energy independent while the other, as expected, shows the energy dependence similar to that of N-α total cross section.

Water infiltration into exposed fractured rock surfaces

International Nuclear Information System (INIS)

Rasmussen, T.C.; Evans, D.D.

1993-01-01

Fractured rock media are present at many existing and potential waste disposal sites, yet characterization data and physical relationships are not well developed for such media. This study focused on water infiltration characteristics of an exposed fractured rock as an approach for defining the upper boundary condition for unsaturated-zone water percolation and contaminant transport modeling. Two adjacent watersheds of 0.24 and 1.73 ha with slopes up to 45% were instrumented for measuring rainfall and runoff. Fracture density was measured from readily observable fracture traces on the surface. Three methods were employed to evaluate the rainfall-runoff relationship. The first method used the annual totals and indicated that only 22.5% of rainfall occurred as runoff for the 1990-1991 water year, which demonstrates a high water intake rate by the exposed fracture system. The second method employed total rainfall and runoff for individual storms in conjunction with the commonly used USDA Soil Conservation Service curve number method developed for wide ranges of soils and vegetation. Curve numbers between 75 and 85 were observed for summer and winter storms with dry antecedent runoff conditions, while values exceeded 90 for wet conditions. The third method used a mass-balance approach for four major storms, which indicated that water intake rates ranged from 2.0 to 7.3 mm h -1 , yielding fracture intake velocities ranging from 122 to 293 m h -1 . The three analyses show the complexity of the infiltration process for fractured rock. However, they contribute to a better understanding of the upper boundary condition for predicting contaminant transport through an unsaturated fractured rock medium. 17 refs., 4 figs., 1 tab

Tuning Fractures With Dynamic Data

Science.gov (United States)

Yao, Mengbi; Chang, Haibin; Li, Xiang; Zhang, Dongxiao

2018-02-01

Flow in fractured porous media is crucial for production of oil/gas reservoirs and exploitation of geothermal energy. Flow behaviors in such media are mainly dictated by the distribution of fractures. Measuring and inferring the distribution of fractures is subject to large uncertainty, which, in turn, leads to great uncertainty in the prediction of flow behaviors. Inverse modeling with dynamic data may assist to constrain fracture distributions, thus reducing the uncertainty of flow prediction. However, inverse modeling for flow in fractured reservoirs is challenging, owing to the discrete and non-Gaussian distribution of fractures, as well as strong nonlinearity in the relationship between flow responses and model parameters. In this work, building upon a series of recent advances, an inverse modeling approach is proposed to efficiently update the flow model to match the dynamic data while retaining geological realism in the distribution of fractures. In the approach, the Hough-transform method is employed to parameterize non-Gaussian fracture fields with continuous parameter fields, thus rendering desirable properties required by many inverse modeling methods. In addition, a recently developed forward simulation method, the embedded discrete fracture method (EDFM), is utilized to model the fractures. The EDFM maintains computational efficiency while preserving the ability to capture the geometrical details of fractures because the matrix is discretized as structured grid, while the fractures being handled as planes are inserted into the matrix grids. The combination of Hough representation of fractures with the EDFM makes it possible to tune the fractures (through updating their existence, location, orientation, length, and other properties) without requiring either unstructured grids or regridding during updating. Such a treatment is amenable to numerous inverse modeling approaches, such as the iterative inverse modeling method employed in this study, which is

Neonatal clavicle fracture in cesarean delivery: incidence and risk factors.

Science.gov (United States)

Choi, Hyun Ah; Lee, Yeon Kyung; Ko, Sun Young; Shin, Son Moon

2017-07-01

Neonatal clavicle fracture in cesarean delivery is rare and has not been extensively studied. We performed a retrospective review of cesarean deliveries with neonatal clavicle fracture during a 12-year period. Maternal and neonatal factors as well as surgical factors related to cesarean delivery for the fracture were determined and compared to the control group to analyze their significance. Among a total 89 367 deliveries during the study period, 36 286 babies were born via cesarean section. Nineteen cases of clavicle fractures in cesarean section were identified (0.05% of total live births via cesarean section). In the analysis of maternal and neonatal risk factors, birthweight, birthweight ≥ 4000  g and maternal age were significantly associated with clavicle fracture in cesarean section. However, clavicle fractures were not correlated with the selected surgical factors such as indication for cesarean section, skin incision to delivery time and incision type of skin and uterus. Logistic regression analysis showed that birthweight was the major risk factor for clavicle fracture. Clavicle fractures complicated 0.05% of cesarean deliveries. The main risk factor related to a clavicle fracture in cesarean section was the birthweight of an infant. As reported in previous studies associated with vaginal delivery, clavicle fracture is considered to be an unavoidable event and may not be eliminated, even in cesarean delivery.

Management of high-energy foot and ankle injuries in the geriatric population.

Science.gov (United States)

Herscovici, Dolfi; Scaduto, Julia M

2012-03-01

By the year 2035 almost 20% of the US population of 389 million people will be 65 years and older. What this group has, compared with aged populations in the past, is better health, more mobility, and more active lifestyles. From January 1989 through December 2010, a total of 494 elderly patients with 536 foot and ankle injuries were identified. Within this group, 237 (48%) patients with 294 injuries were sustained as a result of a high-energy mechanism. These mechanisms consisted of 170 motor vehicle accidents, 30 as a result of high (not ground level) energy falls, 2 from industrial accidents, and 35 classified as other, which included sports, blunt trauma, bicycle, airplane or boating accidents, crush injuries, and injuries resulting from a lawn mower. The injuries produced were 17 metatarsal fractures, 9 Lisfranc injuries, 10 midfoot (navicular, cuneiform, or cuboid) fractures, 23 talus fractures, 63 calcaneal fractures, 73 unimalleolar, bimalleolar, or trimalleolar ankle fractures, 45 pilon fractures, and 3 pure dislocations of the foot or ankle. Overall, 243 (83%) of these injuries underwent surgical fixation and data have shown that when surgery is used to manage high-energy injuries of the foot and ankle in the elderly individuals, the complications and outcomes are similar to those seen in younger patients. Therefore, the decision for surgical intervention for high-energy injuries of the foot and ankle should be based primarily on the injury pattern and not solely on the age of the patient.

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

Science.gov (United States)

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.

Mineral Precipitation in Fractures: Multiscale Imaging and Geochemical Modeling

Science.gov (United States)

Hajirezaie, S.; Peters, C. A.; Swift, A.; Sheets, J. M.; Cole, D. R.; Crandall, D.; Cheshire, M.; Stack, A. G.; Anovitz, L. M.

2017-12-01

For subsurface energy technologies such as geologic carbon sequestration, fractures are potential pathways for fluid migration from target formations. Highly permeable fractures may become sealed by mineral precipitation. In this study, we examined shale specimens with existing cemented fractures as natural analogues, using an array of imaging methods to characterize mineralogy and porosity at several spatial scales. In addition, we used reactive transport modeling to investigate geochemical conditions that can lead to extensive mineral precipitation and to simulate the impacts on fracture hydraulic properties. The naturally-cemented fractured rock specimens were from the Upper Wolfcamp formation in Texas, at 10,000 ft depth. The specimens were scanned using x-ray computed tomography (xCT) at resolution of 13 microns. The xCT images revealed an original fracture aperture of 1.9 mm filled with several distinct mineral phases and vuggy void regions, and the mineral phase volumes and surface areas were quantified and mapped in 3D. Specimens were thin-sectioned and examined at micron- and submicron-scales using petrographic microscopy (PM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and small angle X-ray scattering (SAXS). Collectively these methods revealed crystals of dolomite as large as 900 microns in length overlain with a heterogeneous mixture of carbonate minerals including calcite, dolomite, and Fe-rich dolomite, interspersed at spatial scales as small as 5 microns. In addition, secondary precipitation of SiO2 was found to fill some of the void space. This multiscale imaging was used to inform the reactive transport modeling employed to examine the conditions that can cause the observed mineral precipitation in fractures at a larger scale. Two brines containing solutions that when mixed would lead to precipitation of various carbonate minerals were simulated as injectants into a fracture domain. In particular, the competing

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.

Research on the decomposition model for China’s National Renewable Energy total target

International Nuclear Information System (INIS)

Liu, Zhen; Shi, Yuren; Yan, Jianming; Ou, Xunmin; Lieu, Jenny

2012-01-01

It is crucial that China’s renewable energy national target in 2020 is effectively decomposed into respective period targets at the provincial level. In order to resolve problems arising from combining the national and local renewable energy development plan, a total target and period target decomposition model of renewable energy is proposed which considers the resource distribution and energy consumption of different provinces as well as the development characteristics of various renewable energy industries. In the model, the total proposed target is comprised of three shares: basic share, fixed share and floating share target. The target distributed for each province is then determined by the preference relation. That is, when total renewable energy target is distributed, the central government is more concerned about resources potential or energy consumption. Additionally, the growth models for various renewable energy industries are presented, and the period targets of renewable energy in various provinces are proposed in line with regional economic development targets. In order to verify whether the energy target can be achieved, only wind power, solar power, and hydropower are considered in this study. To convenient to assess the performance of local government, the two year period is chosen as an evaluation cycle in the paper. The renewable energy targets per two-year period for each province are calculated based on the overall national renewable energy target, energy requirements and resources distribution. Setting provincial period targets will help policy makers to better implement and supervise the overall renewable energy plan. - Highlights: It is very importance that the national target of renewable energy in 2020 can be effectively decomposed into the stages target of various province. In order to resolve the relation the plan between the national and local renewable energy development planning, a total target and phase target decomposition model

The Danish Fracture Database can monitor quality of fracture-related surgery, surgeons' experience level and extent of supervision

DEFF Research Database (Denmark)

Andersen, Morten Jon; Gromov, Kirill; Brix, Michael

2014-01-01

INTRODUCTION: The importance of supervision and of surgeons' level of experience in relation to patient outcome have been demonstrated in both hip fracture and arthroplasty surgery. The aim of this study was to describe the surgeons' experience level and the extent of supervision for: 1) fracture......-related surgery in general; 2) the three most frequent primary operations and reoperations; and 3) primary operations during and outside regular working hours. MATERIAL AND METHODS: A total of 9,767 surgical procedures were identified from the Danish Fracture Database (DFDB). Procedures were grouped based...... on the surgeons' level of experience, extent of supervision, type (primary, planned secondary or reoperation), classification (AO Müller), and whether they were performed during or outside regular hours. RESULTS: Interns and junior residents combined performed 46% of all procedures. A total of 90% of surgeries...

The Danish Fracture Database can monitor quality of fracture-related surgery, surgeons' experience level and extent of supervision

DEFF Research Database (Denmark)

Andersen, M. J.; Gromov, K.; Brix, M.

2014-01-01

INTRODUCTION: The importance of supervision and of surgeons' level of experience in relation to patient outcome have been demonstrated in both hip fracture and arthroplasty surgery. The aim of this study was to describe the surgeons' experience level and the extent of supervision for: 1) fracture......-related surgery in general; 2) the three most frequent primary operations and reoperations; and 3) primary operations during and outside regular working hours. MATERIAL AND METHODS: A total of 9,767 surgical procedures were identified from the Danish Fracture Database (DFDB). Procedures were grouped based...... on the surgeons' level of experience, extent of supervision, type (primary, planned secondary or reoperation), classification (AO Muller), and whether they were performed during or outside regular hours. RESULTS: Interns and junior residents combined performed 46% of all procedures. A total of 90% of surgeries...

Investigation of translaminar fracture in fibrereinforced composite laminates---applicability of linear elastic fracture mechanics and cohesive-zone model

Science.gov (United States)

Hou, Fang

With the extensive application of fiber-reinforced composite laminates in industry, research on the fracture mechanisms of this type of materials have drawn more and more attentions. A variety of fracture theories and models have been developed. Among them, the linear elastic fracture mechanics (LEFM) and cohesive-zone model (CZM) are two widely-accepted fracture models, which have already shown applicability in the fracture analysis of fiber-reinforced composite laminates. However, there remain challenges which prevent further applications of the two fracture models, such as the experimental measurement of fracture resistance. This dissertation primarily focused on the study of the applicability of LEFM and CZM for the fracture analysis of translaminar fracture in fibre-reinforced composite laminates. The research for each fracture model consisted of two sections: the analytical characterization of crack-tip fields and the experimental measurement of fracture resistance parameters. In the study of LEFM, an experimental investigation based on full-field crack-tip displacement measurements was carried out as a way to characterize the subcritical and steady-state crack advances in translaminar fracture of fiber-reinforced composite laminates. Here, the fiber-reinforced composite laminates were approximated as anisotropic solids. The experimental investigation relied on the LEFM theory with a modification with respect to the material anisotropy. Firstly, the full-field crack-tip displacement fields were measured by Digital Image Correlation (DIC). Then two methods, separately based on the stress intensity approach and the energy approach, were developed to measure the crack-tip field parameters from crack-tip displacement fields. The studied crack-tip field parameters included the stress intensity factor, energy release rate and effective crack length. Moreover, the crack-growth resistance curves (R-curves) were constructed with the measured crack-tip field parameters

Association of Obesity with Forearm Fractures, Bone Mineral Density and Fracture Risk (FRAX® During Postmenopausal Period

Directory of Open Access Journals (Sweden)

Erkan Mesci

2016-08-01

Full Text Available Objective: The aim of this study was to investigate the association among obesity with bone mineral density (BMD and subsequent fracture risk among postmenopausal women with a previous forearm fracture. Materials and Methods: The study enrolled obese (n=40 and normal-weight (n=40 postmenopausal women who had a previous forearm fracture. BMD measurements were obtained using a GE-LUNAR DPX dual energy X-ray absorptiometry scan for all subjects. FRAX® fracture risk scores were calculated taking into account former fractures and current risk factors of the subjects. Both groups were compared with respect to their BMD values, T scores, FRAX® risk scores and frequency of previous fractures. Results: No difference was observed between groups with regard to mean age, mean age of menopause onset and mean serum calcium, phosphorus and alkaline phosphatase levels (p>0.05 for all. Statistically, obese patients showed highly significantly greater mean BMD values at lumbar spine (L1-L4 and femoral neck in comparison to subjects with normal body weight (p=0.000 for all. Obese patients had a lower 10-year probability of a major osteoporotic fracture on average as determined by FRAX® fracture risk score compared to that in normal-weight subjects (p<0.05. Also, obese group had a lower 10-year probability of a hip fracture versus normal-weight subjects (p<0.01. Both groups were found to have a similar frequency of previous fractures. Conclusion: Although obese patients in this study had greater BMD values and lower FRAX® risk scores, the probability of subsequent fractures predicted for the obese group was not lower when compared to that predicted for normal-weight group. It should be kept in mind that obesity may not necessarily be protective against fractures and treatment algorithms based solely on BMD might be inadequate to predict future fracture risk.

The risk of second hip fracture is decreased with compliant and persistent use of bisphosphonates

DEFF Research Database (Denmark)

Hansen, Louise; Vestergaard, Peter; Petersen, Karin Dam

experience a 19% increased mortality within the first year following hip fractures. Furthermore, studies have shown that within 10 years after first hip fracture 40% will experience another hip fracture. The risk for second hip fracture is markedly increased, initiating at a relative risk of 11.8 within...... the first month after fracture and does not normalise until 15 years later. Fracture prevention programs have focused on identifying patients at risk of secondary low energy trauma fractures. The secondary prevention programs for fractures begin immediately after the first fracture, through identification...... of risk factors and initiate pharmaceutical treatment. The aim of this study was to estimate the potential benefits from alendronate treatment for secondary low energy trauma fracture patients in Denmark, compared to no pharmaceutical treatment for this group of patients. METHODS: A Markov model...

Mandibular ramus fractures: a rarity.

Science.gov (United States)

Kale, Tejraj Pundalik; Kotrashetti, S M; Louis, Archana; Lingaraj, J B; Sarvesh, B U

2013-01-01

To determine the incidence of mandibular ramus fractures in KLE's PK Hospital and to analyze the outcome of open reduction and internal fixation of these fractures. Using a retrospective study design, records of all trauma patients who reported to the Department of Oral and Maxillofacial Surgery, KLE's PK Hospital Belgaum, between the years January 2006 to October 2011 was obtained from the medical records office. The data variables that were analyzed were the name, age, sex, cause of injury, pretreatment occlusion, treatment given, period of MMF and post-treatment occlusion. Total number of mandibular fracture cases was 298. Ramus fractures were 10 in number which accounted for 3.3% of fractures. The age range of these 10 patients was seen to be between 20 to 80 years with the average age being 35.6 years. Of these 10 patients, 9 were male and 1 was female and 7 patients were treated by open reduction and internal fixation and the remaining 3 by closed reduction. The average period of MMF was 3 days for the patients who underwent open reduction and internal fixation. There was improvement in occlusion in all 10 patients post-treatment and there was no complication reported in any of the cases. Ramus fractures accounted for 3.3% of all mandibular fractures. Open reduction and internal fixation of ramus fractures ensures adequate functional and anatomic reduction. This study makes an attempt to throw a light on the increasing incidence of ramus fractures and a successful management of these fractures by open reduction and internal fixation. How to cite this article: Kale TP, Kotrashetti SM, Louis A, Lingaraj JB, Sarvesh BU. Mandibular Ramus Fractures: A Rarity. J Contemp Dent Pract 2013;14(1):39-42. Source of support: Nil Conflict of interest: None declared.

Impact of dietary fiber energy on the calculation of food total energy value in the Brazilian Food Composition Database.

Science.gov (United States)

Menezes, Elizabete Wenzel de; Grande, Fernanda; Giuntini, Eliana Bistriche; Lopes, Tássia do Vale Cardoso; Dan, Milana Cara Tanasov; Prado, Samira Bernardino Ramos do; Franco, Bernadette Dora Gombossy de Melo; Charrondière, U Ruth; Lajolo, Franco Maria

2016-02-15

Dietary fiber (DF) contributes to the energy value of foods and including it in the calculation of total food energy has been recommended for food composition databases. The present study aimed to investigate the impact of including energy provided by the DF fermentation in the calculation of food energy. Total energy values of 1753 foods from the Brazilian Food Composition Database were calculated with or without the inclusion of DF energy. The energy values were compared, through the use of percentage difference (D%), in individual foods and in daily menus. Appreciable energy D% (⩾10) was observed in 321 foods, mainly in the group of vegetables, legumes and fruits. However, in the Brazilian typical menus containing foods from all groups, only D%foods, when individually considered. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

Assessment of Water Resource Sustainability in Energy Production for Hydraulic Fracturing in the Eagle Ford Shale Play, Texas

Science.gov (United States)

Obkirchner, G.; Knappett, P.; Burnett, D.; Bhatia, M.; Mohtar, R.

2017-12-01

The Eagle Ford shale is one of the largest producers of shale oil globally. It is located in a semi-arid region of South Central Texas where hydraulic fracturing for oil and gas production accounts for 16% of total water consumption in Region L Groundwater Management Area (GMA). Because water is largely supplied through groundwater sources, it is critical to understand, monitor, and predict future groundwater budgets to keep up with growing demands from the municipal and energy sectors to improve its management and sustainability. Within the Texas A&M University Water-Energy-Food (WEF) Nexus Initiative and research group, tools have been developed that quantify the interrelations between water, energy, and transportation within Region L and calculate the environmental needs/outcomes to reach optimum levels of oil and gas production. These tools will be combined with a groundwater budget model to fully integrate groundwater limitations and enhance the resiliency of energy production. With about half of oil and gas production wells located in high to extremely high water stress areas, monitoring and modeling must be drastically improved to predict the impacts of various spatial distributions of pumping rates on future aquifer conditions. These changing conditions will impact the cost of water production in an aquifer. Combining the WEF Nexus tools with hydrologic models creates a multi-disciplinary sustainability assessment model that calculates social and economic constraints from an area's limited water resources. This model will allow industry, governments and scientists to plan through evaluating the impacts of any number of growth, conservation and reuse scenarios across different water usage sectors on groundwater supplies.

Incidence and epidemiology of tibial shaft fractures.

Science.gov (United States)

Larsen, Peter; Elsoe, Rasmus; Hansen, Sandra Hope; Graven-Nielsen, Thomas; Laessoe, Uffe; Rasmussen, Sten

2015-04-01

The literature lacks recent population-based epidemiology studies of the incidence, trauma mechanism and fracture classification of tibial shaft fractures. The purpose of this study was to provide up-to-date information on the incidence of tibial shaft fractures in a large and complete population and report the distribution of fracture classification, trauma mechanism and patient baseline demographics. Retrospective reviews of clinical and radiological records. A total of 196 patients were treated for 198 tibial shaft fractures in the years 2009 and 2010. The mean age at time of fracture was 38.5 (21.2SD) years. The incidence of tibial shaft fracture was 16.9/100,000/year. Males have the highest incidence of 21.5/100,000/year and present with the highest frequency between the age of 10 and 20, whereas women have a frequency of 12.3/100,000/year and have the highest frequency between the age of 30 and 40. AO-type 42-A1 was the most common fracture type, representing 34% of all tibial shaft fractures. The majority of tibial shaft fractures occur during walking, indoor activity and sports. The distribution among genders shows that males present a higher frequency of fractures while participating in sports activities and walking. Women present the highest frequency of fractures while walking and during indoor activities. This study shows an incidence of 16.9/100,000/year for tibial shaft fractures. AO-type 42-A1 was the most common fracture type, representing 34% of all tibial shaft fractures. Copyright © 2015 Elsevier Ltd. All rights reserved.

Reprint of: The impact of fragility fracture and approaches to osteoporosis risk assessment worldwide.

Science.gov (United States)

Curtis, Elizabeth M; Moon, Rebecca J; Harvey, Nicholas C; Cooper, Cyrus

2017-08-01

Osteoporosis constitutes a major public health problem, through its association with age-related fractures, particularly of the hip, vertebrae, distal forearm and humerus. Substantial geographic variation has been noted in the incidence of osteoporotic fractures worldwide, with Western populations (North America, Europe and Oceania), reporting increases in hip fracture throughout the second half of the 20th century, with a stabilisation or decline in the last two decades. In developing populations however, particularly in Asia, the rates of osteoporotic fracture appears to be increasing. The massive global burden consequent to osteoporosis means that fracture risk assessment should be a high priority amongst health measures considered by policy makers. The WHO operational definition of osteoporosis, based on a measurement of bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA), has been used globally since the mid-1990s. However, although this definition identifies those at greatest individual risk of fracture, in the population overall a greater total number of fractures occur in individuals with BMD values above threshold for osteoporosis diagnosis. A number of web-based tools to enable the inclusion of clinical risk factors, with or without BMD, in fracture prediction algorithms have been developed to improve the identification of individuals at high fracture risk, the most commonly used globally being FRAX ® . Access to DXA, osteoporosis risk assessment, case finding and treatment varies worldwide, but despite such advances studies indicate that a minority of men and women at high fracture risk receive treatment. Importantly, research is ongoing to demonstrate the clinical efficacy and cost-effectiveness of osteoporosis case finding and risk assessment strategies worldwide. The huge burden caused by osteoporosis related fractures to individuals, healthcare systems and societies should provide a clear impetus for the progression of such

Experimental Study On Fracture Property Of Tapered Double Cantilever Beam Specimen With Aluminum Foam

Directory of Open Access Journals (Sweden)

Kim Y.C.

2015-06-01

Full Text Available It is indispensable to evaluate fracture energy as the bonding strength of adhesive at composite material with aluminum foam. This specimen is designed with tapered double cantilever beam by British standards (BS 7991 and ISO 11343. 4 kinds of specimens due to m values of 2, 2.5, 3 and 3.5 are manufactured and compared each other with the experimental results. Adhesive fracture energy is calculated from the formulae of British standards. The value of m is the gradient which is denoted as the length and the height of specimen. As m becomes greater at static experimental result, the maximum load becomes higher and the displacement becomes lower. And the critical fracture energy becomes higher. As m becomes less at fatigue experimental result, the displacement becomes higher and the critical fracture energy becomes higher. Fracture behavior of adhesive can be analyzed by this study and these experimental results can be applied into real field effectively. The stability on TDCB structure bonded with aluminum foam composite can be predicted by use of this experimental result. Adhesive fracture energy is calculated from the formulae of British standards. Based on correlations obtained in this study, the fracture behavior of bonded material would possibly be analyzed and aluminum foam material bonded with adhesive would be applied to a composite structure in various fields, thereby analyzing the mechanical and fracture characteristic of the material.

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.

Ipsilateral humeral neck and shaft fractures

Directory of Open Access Journals (Sweden)

Zhu Bin

2017-01-01

Full Text Available Background/Aim. Fractures of the proximal humerus or shaft are common, however, ipsilateral neck and shaft humerus fracture is a rare phenomenon. This combination injury is challenging for orthopaedic surgeons because of its complex treatment options at present. The purpose of this study was to review a series of ipsilateral humeral neck and shaft fractures to study the fracture pattern, complications and treatment outcomes of each treatment options used. Methods. A total of six patients (four female and two male with the average age of 42.8 years (range: 36–49 years was collected and reviewed retrospectively. Two of them were treated with double plates and four with antegrade intramedullary nail. According to the Neer’s classification, all proximal fractures were two-part surgical neck fractures. All humeral shaft fractures were located at the middle of one third. Five fractures were simple transverse (A3, one fragmented wedge fracture (B3. One patient had associated radial nerve palsy. Results. All surgical neck fractures except one united uneventfully in the average time span of 8.7 weeks. Four humeral shaft fractures healed in near anatomic alignment. The remaining two patients had the nonunion with no radiological signs of fracture healing. The average University of California, Los Angeles End-Results (UCLA score was 23.1. On the contrary, the average American Shoulder and Elbow Surgeon's (ASES score was 73.3. The patients treated with antegrade intramedullary nails presented 70.5 points. The ASES scores were 79 in the double plates group. Conclusions. Ipsilateral humeral shaft and neck fracture is extremely rare. Both antegrade intramedullar nailing and double plates result in healing of fractures. However the risk of complication is lower in the double plating group.

Comparison of femoral morphology and bone mineral density between femoral neck fractures and trochanteric fractures.

Science.gov (United States)

Maeda, Yuki; Sugano, Nobuhiko; Saito, Masanobu; Yonenobu, Kazuo

2011-03-01

Many studies that analyzed bone mineral density (BMD) and skeletal factors of hip fractures were based on uncalibrated radiographs or dual-energy xray absorptiometry (DXA). Spatial accuracy in measuring BMD and morphologic features of the femur with DXA is limited. This study investigated differences in BMD and morphologic features of the femur between two types of hip fractures using quantitative computed tomography (QCT). Forty patients with hip fractures with normal contralateral hips were selected for this study between 2003 and 2007 (trochanteric fracture, n=18; femoral neck fracture, n=22). Each patient underwent QCT of the bilateral femora using a calibration phantom. Using images of the intact contralateral femur, BMD measurements were made at the point of minimum femoral-neck cross-sectional area, middle of the intertrochanteric region, and center of the femoral head. QCT images also were used to measure morphologic features of the hip, including hip axis length, femoral neck axis length, neck-shaft angle, neck width, head offset, anteversion of the femoral neck, and cortical index at the femoral isthmus. No significant differences were found in trabecular BMD between groups in those three regions. Patients with trochanteric fractures showed a smaller neck shaft angle and smaller cortical index at the femoral canal isthmus compared with patients with femoral neck fractures. We conclude that severe osteoporosis with thinner cortical bone of the femoral diaphysis is seen more often in patients with trochanteric fracture than in patients with femoral neck fracture. Level IV, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Paratrooper's ankle fracture: posterior malleolar fracture.

Science.gov (United States)

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

In situ grain fracture mechanics during uniaxial compaction of granular solids

Science.gov (United States)

Hurley, R. C.; Lind, J.; Pagan, D. C.; Akin, M. C.; Herbold, E. B.

2018-03-01

Grain fracture and crushing are known to influence the macroscopic mechanical behavior of granular materials and be influenced by factors such as grain composition, morphology, and microstructure. In this paper, we investigate grain fracture and crushing by combining synchrotron x-ray computed tomography and three-dimensional x-ray diffraction to study two granular samples undergoing uniaxial compaction. Our measurements provide details of grain kinematics, contacts, average intra-granular stresses, inter-particle forces, and intra-grain crystal and fracture plane orientations. Our analyses elucidate the complex nature of fracture and crushing, showing that: (1) the average stress states of grains prior to fracture vary widely in their relation to global and local trends; (2) fractured grains experience inter-particle forces and stored energies that are statistically higher than intact grains prior to fracture; (3) fracture plane orientations are primarily controlled by average intra-granular stress and contact fabric rather than the orientation of the crystal lattice; (4) the creation of new surfaces during fracture accounts for a very small portion of the energy dissipated during compaction; (5) mixing brittle and ductile grain materials alters the grain-scale fracture response. The results highlight an application of combined x-ray measurements for non-destructive in situ analysis of granular solids and provide details about grain fracture that have important implications for theory and modeling.

Developing a Fracture Model of the Granite Rocks Around the Research Tunnel at the Mizunami Underground Research Laboratory in Central Japan

Science.gov (United States)

Kalinina, E.; Hadgu, T.; Wang, Y.

2017-12-01

The Mizunami Underground Research Laboratory (MIU) is located in Tono area in Central Japan. It is operated by the Japan Atomic Energy Agency (JAEA) with the main purpose of providing scientific basis for the research and development of technologies needed for deep geological disposal of radioactive waste in fractured crystalline rocks. The current work is focused on the research and experiments in the tunnel located at 500 m depth. The data collected in the tunnel and exploratory boreholes were shared with the participants of the DEvelopment of COupled models and their VALidation against EXperiments (DECOVALEX), an international research and model comparison collaboration. This study describes the development of the fracture model representing granite rocks around the research tunnel. The model domain is 100x150x100m with the main experimental part of the tunnel, Closure Test Drift, located approximately in the center. The major input data were the fracture traces measured on the tunnel walls (total of 2,023 fractures), fractures observed in the horizontal borehole parallel to the tunnel, and the packer tests conducted in this borehole and one vertical borehole located within the modeling domain. 78 fractures (the ones with the inflow) in the tunnel were incorporated in the development of the fracture model. Fracture size was derived from the fracture trace analysis. It was shown that the fracture radius followed lognormal distributions. Fracture transmissivity was estimated from an analytical solution of inflow into the tunnel through an individual fracture and the total measured inflow into the tunnel. 16 fractures were incorporated in the model along the horizontal borehole. The packer test data in the different well intervals were used to estimate the range in fracture transmissivity. A relationship between the fracture transmissivity and fracture radius was developed. The fractures in the tunnel and borehole were used to derive fracture orientation and

Energy efficiency improvement: A strong driver for Total operations and R and D

Energy Technology Data Exchange (ETDEWEB)

Garnaud, Frederic; Rocher, Anne

2010-09-15

Total has implemented an energy efficiency action plan for both producing fields and new projects linked to a dedicated R and D program. The Energy efficiency assessment methodology is described, with an example: base line of the current situation, energy efficiency plan, contribution to best practices at corporate level. A methodology to assess the energy efficiency of a new development has been defined and implemented within Total. This methodology as well as related indicators is presented. Examples of R and D results dedicated to improve energy efficiency in two major areas of future developments are given: sour gas production and deep offshore field architecture.

Prevalence and characteristics of rib fractures in ex-preterm infants.

Science.gov (United States)

Lucas-Herald, Angela; Butler, Sandra; Mactier, Helen; McDevitt, Helen; Young, David; Ahmed, Syed Faisal

2012-12-01

This study aimed to identify the prevalence and characteristics of rib fractures in ex-preterm infants. Infants born at rib fractures, and the case notes of all affected individuals were scrutinized. Of the 3318 eligible preterm infants, 1446 had a total of 9386 chest radiographs. Of these infants, 26 (1.8%) were identified as having a total of 62 rib fractures. Their median (range) gestation at birth was 26 weeks (23-34). The median chronological age of these infants at the time of the radiograph was 14 weeks (5 weeks to 8 months). The median corrected gestational age at the time of the radiograph was 39 weeks (34 weeks to 4 months). Of the 62 fractures, 27 (36%) were sited posteriorly, and 15 (53%) of the infants with posterior rib fractures were diagnosed with osteopathy of prematurity. Classic risk including conjugated hyperbilirubinemia and diuretics, were present in 23 of 26 (88%) infants. A full skeletal survey was performed in 8 of 26 (31%). Investigations for nonaccidental injury occurred in 4 of 26 (15%) cases. Evidence of rib fractures is present in ~2% of ex-preterm infants. The evaluation of these fractures in infancy requires a detailed neonatal history irrespective of the site of rib fracture.

Elastic-plastic fracture mechanics of compact bone

Science.gov (United States)

Yan, Jiahau

Bone is a composite composed mainly of organics, minerals and water. Most studies on the fracture toughness of bone have been conducted at room temperature. Considering that the body temperature of animals is higher than room temperature, and that bone has a high volumetric percentage of organics (generally, 35--50%), the effect of temperature on fracture toughness of bone should be studied. Single-edged V-shaped notched (SEVN) specimens were prepared to measure the fracture toughness of bovine femur and manatee rib in water at 0, 10, 23, 37 and 50°C. The fracture toughness of bovine femur and manatee rib were found to decrease from 7.0 to 4.3 MPa·m1/2 and from 5.5 to 4.1 MPa·m1/2, respectively, over a temperature range of 50°C. The decreases were attributed to inability of the organics to sustain greater stresses at higher temperatures. We studied the effects of water and organics on fracture toughness of bone using water-free and organics-free SEVN specimens at 23°C. Water-free and organics-free specimens were obtained by placing fresh bone specimen in a furnace at different temperatures. Water and organics significantly affected the fracture toughness of bone. Fracture toughness of the water-free specimens was 44.7% (bovine femur) and 32.4% (manatee rib) less than that of fresh-bone specimens. Fracture toughness of the organics-free specimens was 92.7% (bovine femur) and 91.5% (manatee rib) less than that of fresh bone specimens. Linear Elastic Fracture Mechanics (LEFM) is widely used to study bone. However, bone often has small to moderate scale yielding during testing. We used J integral, an elastic-plastic fracture-mechanics parameter, to study the fracture process of bone. The J integral of bovine femur increased from 6.3 KJ/mm2 at 23°C to 6.7 KJ/mm2 at 37°C. Although the fracture toughness of bovine bone decreases as the temperature increases, the J integral results show a contrary trend. The energy spent in advancing the crack beyond the linear

Hydromechanical modeling of clay rock including fracture damage

Science.gov (United States)

Asahina, D.; Houseworth, J. E.; Birkholzer, J. T.

2012-12-01

grid and associated nodes, where the scalar field quantities (e.g. temperature, pressure, and saturation) and the generalized displacements are obtained by an integral finite difference method (e.g., TOUGH2) and RBSN, respectively. Fractures propagate along Voronoi cell boundaries as induced stresses evolve and exceed the material strength. Examples of fracture propagation in clay rock are examined for the excavation disturbed zone and for cases in which hydraulic overpressure leads to hydraulic fracture. Fluid flow behavior in these evolving fracture networks and eventual fracture closing and self-sealing are investigated. Funding for this work was provided by the Used Fuel Disposition Campaign, Office of Nuclear Energy, of the U.S. Department of Energy under Contract NumberDE-AC02-05CH11231 with Berkeley Lab.

Fracture Assessment of PEEK under Static Loading by Means of the Local Strain Energy Density

Directory of Open Access Journals (Sweden)

Mirco Peron

2017-12-01

Full Text Available Polyetheretherketone (PEEK has gained interest in many industrial applications due to its high strength-to-weight ratio, excellent heat tolerance and high corrosion resistance. Stress concentrators such as notches and geometrical discontinuities are present in many such components necessitating the reliable assessment of notch sensitivity of PEEK in monotonic tension. Here we evaluate the applicability of the strain energy density (SED approach for the assessment of the fracture strength of experimentally tested notched geometries subject to corrosion. The fracture behavior of neat, circumferentially razor-grooved dog-bone specimens and circumferentially U-notched specimens with different notch radii can be predicted with a discrepancy lower than ±10%. Reliable predictions are shown on two previously published datasets employing both computed and published mechanical properties as inputs for the SED calculations. This report presents the first successful application of SED for PEEK as well as the successful prediction of tensile behavior in corrosive environments. This opens the road towards future applications of PEEK in fields its compliant use is of growing popularity.

Early Onset of Laying and Bumblefoot Favor Keel Bone Fractures

Science.gov (United States)

Gebhardt-Henrich, Sabine G.; Fröhlich, Ernst K. F.

2015-01-01

Simple Summary Numerous studies have documented a high prevalence of keel bone fractures in laying hens. In this longitudinal study, 80 white and brown laying hens were regularly checked for keel bone deviations and fractures while egg production was individually monitored. About 62% of the hens had broken keel bones at depopulation. More new fractures occurred during the time when laying rates were highest. Hens with broken keel bones at depopulation had laid their first egg earlier than hens with intact keel bones. All birds with bumblefoot on both feet had a fracture at depopulation. Abstract Numerous studies have demonstrated influences of hybrid, feed, and housing on prevalence of keel bone fractures, but influences of behavior and production on an individual level are less known. In this longitudinal study, 80 white and brown laying hens were regularly checked for keel bone deviations and fractures while egg production was individually monitored using Radio Frequency Identification (RFID) from production until depopulation at 65 weeks of age. These focal birds were kept in eight pens with 20 hens per pen in total. About 62% of the hens had broken keel bones at depopulation. The occurrence of new fractures was temporally linked to egg laying: more new fractures occurred during the time when laying rates were highest. Hens with fractured keel bones at depopulation had laid their first egg earlier than hens with intact keel bones. However, the total number of eggs was neither correlated with the onset of egg laying nor with keel bone fractures. All birds with bumblefoot on both feet had a fracture at depopulation. Hens stayed in the nest for a longer time during egg laying during the ten days after the fracture than during the ten days before the fracture. In conclusion, a relationship between laying rates and keel bone fractures seems likely. PMID:26633520

Clinical Utility of Chest Computed Tomography in Patients with Rib Fractures CT Chest and Rib Fractures.

Science.gov (United States)

Chapman, Brandon C; Overbey, Douglas M; Tesfalidet, Feven; Schramm, Kristofer; Stovall, Robert T; French, Andrew; Johnson, Jeffrey L; Burlew, Clay C; Barnett, Carlton; Moore, Ernest E; Pieracci, Fredric M

2016-12-01

Chest CT is more sensitive than a chest X-ray (CXR) in diagnosing rib fractures; however, the clinical significance of these fractures remains unclear. The purpose of this study was to determine the added diagnostic use of chest CT performed after CXR in patients with either known or suspected rib fractures secondary to blunt trauma. Retrospective cohort study of blunt trauma patients with rib fractures at a level I trauma center that had both a CXR and a CT chest. The CT finding of ≥ 3 additional fractures in patients with ≤ 3 rib fractures on CXR was considered clinically meaningful. Student's t-test and chi-square analysis were used for comparison. We identified 499 patients with rib fractures: 93 (18.6%) had CXR only, 7 (1.4%) had chest CT only, and 399 (79.9%) had both CXR and chest CT. Among these 399 patients, a total of 1,969 rib fractures were identified: 1,467 (74.5%) were missed by CXR. The median number of additional fractures identified by CT was 3 (range, 4 - 15). Of 212 (53.1%) patients with a clinically meaningful increase in the number of fractures, 68 patients underwent one or more clinical interventions: 36 SICU admissions, 20 pain catheter placements, 23 epidural placements, and 3 SSRF. Additionally, 70 patients had a chest tube placed for retained hemothorax or occult pneumothorax. Overall, 138 patients (34.5%) had a change in clinical management based upon CT chest. The chest X-ray missed ~75% of rib fractures seen on chest CT. Although patients with a clinical meaningful increase in the number of rib fractures were more likely to be admitted to the intensive care unit, there was no associated improvement in pulmonary outcomes.

a Fractal Network Model for Fractured Porous Media

Science.gov (United States)

Xu, Peng; Li, Cuihong; Qiu, Shuxia; Sasmito, Agus Pulung

2016-04-01

The transport properties and mechanisms of fractured porous media are very important for oil and gas reservoir engineering, hydraulics, environmental science, chemical engineering, etc. In this paper, a fractal dual-porosity model is developed to estimate the equivalent hydraulic properties of fractured porous media, where a fractal tree-like network model is used to characterize the fracture system according to its fractal scaling laws and topological structures. The analytical expressions for the effective permeability of fracture system and fractured porous media, tortuosity, fracture density and fraction are derived. The proposed fractal model has been validated by comparisons with available experimental data and numerical simulation. It has been shown that fractal dimensions for fracture length and aperture have significant effect on the equivalent hydraulic properties of fractured porous media. The effective permeability of fracture system can be increased with the increase of fractal dimensions for fracture length and aperture, while it can be remarkably lowered by introducing tortuosity at large branching angle. Also, a scaling law between the fracture density and fractal dimension for fracture length has been found, where the scaling exponent depends on the fracture number. The present fractal dual-porosity model may shed light on the transport physics of fractured porous media and provide theoretical basis for oil and gas exploitation, underground water, nuclear waste disposal and geothermal energy extraction as well as chemical engineering, etc.

Hydraulic fracturing in granite under geothermal conditions

Science.gov (United States)

Solberg, P.; Lockner, D.; Byerlee, J.D.

1980-01-01

The experimental hydraulic fracturing of granite under geothermal conditions produces tensile fracture at rapid fluid injection rates and shear fracture at slow injection rates and elevated differential stress levels. A sudden burst of acoustic emission activity accompanies tensile fracture formation whereas the acoustic emission rate increases exponentially prior to shear fracture. Temperature does not significantly affect the failure mechanism, and the experimental results have not demonstrated the occurrence of thermal fracturing. A critical result of these experiments is that fluid injection at intermediate rates and elevated differential stress levels increases permeability by more than an order of magnitude without producing macroscopic fractures, and low-level acoustic emission activity occurs simultaneously near the borehole and propagates outward into the specimen with time. Permeability measurements conducted at atmospheric pressure both before and after these experiments show that increased permeability is produced by permanent structural changes in the rock. Although results of this study have not demonstrated the occurrence of thermal fracturing, they suggest that fluid injection at certain rates in situ may markedly increase local permeability. This could prove critical to increasing the efficiency of heat exchange for geothermal energy extraction from hot dry rock. ?? 1980.

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.

Rib fractures: comparison of associated injuries between pediatric and adult population.

Science.gov (United States)

Kessel, Boris; Dagan, Jasmin; Swaid, Forat; Ashkenazi, Itamar; Olsha, Oded; Peleg, Kobi; Givon, Adi; Alfici, Ricardo

2014-11-01

Rib fractures are considered a marker of exposure to significant traumatic energy. In children, because of high elasticity of the chest wall, higher energy levels are necessary for ribs to fracture. The purpose of this study was to analyze patterns of associated injuries in children as compared with adults, all of whom presented with rib fractures. A retrospective cohort study involving blunt trauma patients with rib fractures registered in the National Trauma Registry was conducted. Of 6,995 trauma victims who were found to suffer from rib fractures, 328 were children and 6,627 were adults. Isolated rib fractures without associated injuries occurred in 19 children (5.8%) and 731 adults (11%). More adults had 4 or more fractured ribs compared with children (P pneumothorax (P = .006), spleen, and liver injury (P < .001). Mortality rate was 5% in both groups. The incidence of associated head, thoracic, and abdominal solid organ injuries in children was significantly higher than in adults suffering from rib fractures. In spite of a higher Injury Severity Score and incidence of associated injuries, mortality rate was similar. Mortality of rib fracture patients was mostly affected by the presence of extrathoracic injuries. Copyright © 2014 Elsevier Inc. All rights reserved.

6,7Li + 28Si total reaction cross sections at near barrier energies

International Nuclear Information System (INIS)

Pakou, A.; Musumarra, A.; Pierroutsakou, D.; Alamanos, N.; Assimakopoulos, P.A.; Divis, N.; Doukelis, G.; Gillibert, A.; Harissopulos, S.; Kalyva, G.; Kokkoris, M.; Lagoyannis, A.; Mertzimekis, T.J.; Nicolis, N.G.; Papachristodoulou, C.; Perdikakis, G.; Roubos, D.; Rusek, K.; Spyrou, S.; Zarkadas, Ch.

2007-01-01

Total reaction cross section measurements for the 6,7 Li + 28 Si systems have been performed at near-barrier energies. The results indicate that, with respect to the potential anomaly at barrier, 6 Li and 7 Li on light targets exhibit similar energy dependence on the imaginary potential. Comparisons are made with 6,7 Li cross sections on light and heavy targets, extracted via previous elastic scattering measurements and also with CDCC calculations. Energy dependent parametrisations are also obtained for total reaction cross sections of 6,7 Li on Si, as well as on any target, at near barrier energies

Study of the fracture behavior of mortar and concretes with crushed rock or pebble aggregates

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Sebastião Ribeiro

2011-03-01

Full Text Available The objective of this work was to compare the fracture energy of mortar and concretes produced with crushed rock and pebble aggregates using zero, 10, 20, 30 and 40% of aggregates mixed with standard mortar and applying the wedge splitting method to achieve stable crack propagation. The samples were cast in a special mold and cured for 28 days, after which they were subjected to crack propagation tests by the wedge splitting method to determine the fracture energies of the mortar and concrete. The concretes showed higher fracture energy than the mortar, and the concretes containing crushed rock showed higher resistance to crack propagation than all the compositions containing pebbles. The fracture energy varied from 38 to 55 J.m-2. A comparison of the number of aggregates that separated from the two concrete matrices with the highest fracture energies indicated that the concrete containing pebbles crumbled more easily and was therefore less resistant to crack propagation.

Energy consumption and total factor productivity growth in Iranian agriculture

Directory of Open Access Journals (Sweden)

Reza Moghaddasi

2016-11-01

Full Text Available In this study we investigated the relation between energy consumption and growth of total factor productivity (TFP of agriculture in Iran from 1974 to 2012 using Solow residual method. The results from estimated aggregate Cobb–Douglas production function showed that one percent change in the value of labor, capital and energy will lead to 4.07, 0.09 and 0.49 percent change in agriculture value added, respectively. Also in a long term, based on the Johansen cointegration test, there is a negative relation between TFP growth and energy consumption in Iranian agriculture which might be due to cheap and inefficient energy use in this sector. Gradual liberalization of energy price and use of so called green box support policies is recommended.

The role of chair exercises for older adults following hip fracture

African Journals Online (AJOL)

for older adults following hip fracture. Claire M ... women temporarily disabled as a result of a fracture and ... recovering from hip fracture surgery are not very promising. ... investigation was to examine the influence of exercise on ..... from estimated energy expenditure relative to the reported ..... physical activity: A review. Jor.

An updated hip fracture projection in Asia: The Asian Federation of Osteoporosis Societies study

Directory of Open Access Journals (Sweden)

Ching-Lung Cheung

2018-03-01

Full Text Available Objectives: Hip fracture is a major public health problem. Earlier studies projected that the total number of hip fracture will increase dramatically by 2050, and most of the hip fracture will occur in Asia. To date, only a few studies provided the updated projection, and none of them focused on the hip fracture projection in Asia. Thus, it is essential to provide the most up to date prediction of hip fracture in Asia, and to evaluate the total direct medical cost of hip fracture in Asia. Methods: We provide the updated projection of hip fracture in 9 Asian Federation of Osteoporosis Societies members using the most updated incidence rate and projected population size. Results: We show that the number of hip fracture will increase from 1,124,060 in 2018 to 2,563,488 in 2050, a 2.28-fold increase. This increase is mainly due to the changes on the population demographics, especially in China and India, which have the largest population size. The direct cost of hip fracture will increase from 9.5 billion United State dollar (USD in 2018 to 15 billion USD in 2050, resulting a 1.59-fold increase. A 2%–3% decrease in incidence rate of hip fracture annually is required to keep the total number of hip fracture constant over time. Conclusions: The results show that hip fracture remains a key public health issue in Asia, despite the available of better diagnosis, treatment, and prevention of fracture over the recent years. Healthcare policy in Asia should be aimed to reduce the burden of hip fracture. Keywords: Hip fracture, Asia, Osteoporosis, Incidence

CHARACTERIZATION OF IN-SITU STRESS AND PERMEABILITY IN FRACTURED RESERVOIRS

Energy Technology Data Exchange (ETDEWEB)

Daniel R. Burns; M. Nafi Toksoz

2004-07-19

Expanded details and additional results are presented on two methods for estimating fracture orientation and density in subsurface reservoirs from scattered seismic wavefield signals. In the first, fracture density is estimated from the wavenumber spectra of the integrated amplitudes of the scattered waves as a function of offset in pre-stack data. Spectral peaks correctly identified the 50m, 35m, and 25m fracture spacings from numerical model data using a 40Hz source wavelet. The second method, referred to as the Transfer Function-Scattering Index Method, is based upon observations from 3D finite difference modeling that regularly spaced, discrete vertical fractures impart a ringing coda-type signature to any seismic energy that is transmitted through or reflected off of them. This coda energy is greatest when the acquisition direction is parallel to the fractures, the seismic wavelengths are tuned to the fracture spacing, and when the fractures have low stiffness. The method uses surface seismic reflection traces to derive a transfer function, which quantifies the change in an apparent source wavelet propagating through a fractured interval. The transfer function for an interval with low scattering will be more spike-like and temporally compact. The transfer function for an interval with high scattering will ring and be less temporally compact. A Scattering Index is developed based on a time lag weighting of the transfer function. When a 3D survey is acquired with a full range of azimuths, the Scattering Index allows the identification of subsurface areas with high fracturing and the orientation (or strike) of those fractures. The method was calibrated with model data and then applied to field data from a fractured reservoir giving results that agree with known field measurements. As an aid to understanding the scattered wavefield seen in finite difference models, a series of simple point scatterers was used to create synthetic seismic shot records collected over

Achievement report for fiscal 1981 on Sunshine Program-entrusted research and development. Research on hydrogen energy total system; 1981 nendo suiso energy total system no kenkyu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1982-03-01

In this research, studies are conducted relative to the time point, form, and magnitude of the introduction of hydrogen into Japan's total energy system. The research aims to construct a hydrogen energy total system consisting of hydrogen energy subsystems to be available in the future and to clearly define the stage at which transfer to the target system will be carried out. In the research for fiscal 1981, studies continue about the feasibility of hydrogen as automobile and aviation fuels and as a material for use in chemical engineering, about conversion into each other of hydrogen and various synthetic fuels and electric power with which hydrogen will have to compete in the domain into which it will be supplied, and about technologies of their utilization for comparison between such energies in the search for their interchangeability. Surveys are conducted on technical data about local energies. The Yakushima island is chosen, for instance, and a conceptual hydrogen energy base is constructed there and the cost for the construction is estimated. At the last part, the feasibility of the introduction of hydrogen into Japan's energy system in the future is discussed for assessment. (NEDO)

Radiographically Occult and Subtle Fractures: A Pictorial Review

International Nuclear Information System (INIS)

Jarraya, M.; Hayashi, D.; Roemer, F.W.; Crema, M.D.; Conlin, J.; Marra, M.D.; Guermazi, A.; Roemer, F.W.; Crema, M.D.; Diaz, L.; Conlin, J.; Jomaah, N.

2013-01-01

Radiographically occult and subtle fractures are a diagnostic challenge. They may be divided into (1) high energy trauma fracture, (2) fatigue fracture from cyclical and sustained mechanical stress, and (3) insufficiency fracture occurring in weakened bone (e.g., in osteoporosis and post radiotherapy). Independently of the cause, the initial radiographic examination can be negative either because the findings seem normal or are too subtle. Early detection of these fractures is crucial to explain the patients symptoms and prevent further complications. Advanced imaging tools such as computed tomography, magnetic resonance imaging, and scintigraphy are highly valuable in this context. Our aim is to raise the awareness of radiologists and clinicians in these cases by presenting illustrative cases and a discussion of the relevant literature.

Relativistic total energy and chemical potential of heavy atoms and positive ions

International Nuclear Information System (INIS)

Hill, S.H.; Grout, P.J.; March, N.H.

1984-01-01

The relativistic Thomas-Fermi theory, with a finite nucleus, is used to study the variation of the chemical potential μ with atomic number Z and number of electrons N (N <= Z). The difference between the total energy of positive ions and that of the corresponding neutral atom has been obtained. The scaling predictions are confirmed by numerical calculations. The first principles calculation of the relativistic Thomas-Fermi total energy of neutral atoms is also studied. (author)

Fracture processes studied in CRESST

International Nuclear Information System (INIS)

Astroem, J.; Proebst, F.; Di Stefano, P.C.F.; Stodolsky, L.; Timonen, J.; Bucci, C.; Cooper, S.; Cozzini, C.; Feilitzsch, F. von; Kraus, H.; Marchese, J.; Meier, O.; Nagel, U.; Ramachers, Y.; Seidel, W.; Sisti, M.; Uchaikin, S.; Zerle, L.

2006-01-01

In the early stages of running of the CRESST dark matter search with sapphire crystals as detectors, an unexpectedly high rate of signal pulses appeared. Their origin was finally traced to fracture events in the sapphire due to the very tight clamping of the detectors. During extensive runs the energy and time of each event was recorded, providing large data sets for such phenomena. We believe this is the first time that the energy release in fracture has been accurately measured on a microscopic event-by-event basis. The energy distributions appear to follow a power law, dN/dE∝E -β , similar to the Gutenberg-Richter power law for earthquake magnitudes, and after appropriate translation, with a similar exponent. In the time domain, the autocorrelation function shows time correlations lasting for substantial parts of an hour. Some remarks are made concerning the possible role of such mechanical stress release processes in the noise of sensitive cryodetectors

Development of a Korean Fracture Risk Score (KFRS for Predicting Osteoporotic Fracture Risk: Analysis of Data from the Korean National Health Insurance Service.

Directory of Open Access Journals (Sweden)

Ha Young Kim

Full Text Available Asian-specific prediction models for estimating individual risk of osteoporotic fractures are rare. We developed a Korean fracture risk prediction model using clinical risk factors and assessed validity of the final model.A total of 718,306 Korean men and women aged 50-90 years were followed for 7 years in a national system-based cohort study. In total, 50% of the subjects were assigned randomly to the development dataset and 50% were assigned to the validation dataset. Clinical risk factors for osteoporotic fracture were assessed at the biennial health check. Data on osteoporotic fractures during the follow-up period were identified by ICD-10 codes and the nationwide database of the National Health Insurance Service (NHIS.During the follow-up period, 19,840 osteoporotic fractures were reported (4,889 in men and 14,951 in women in the development dataset. The assessment tool called the Korean Fracture Risk Score (KFRS is comprised of a set of nine variables, including age, body mass index, recent fragility fracture, current smoking, high alcohol intake, lack of regular exercise, recent use of oral glucocorticoid, rheumatoid arthritis, and other causes of secondary osteoporosis. The KFRS predicted osteoporotic fractures over the 7 years. This score was validated using an independent dataset. A close relationship with overall fracture rate was observed when we compared the mean predicted scores after applying the KFRS with the observed risks after 7 years within each 10th of predicted risk.We developed a Korean specific prediction model for osteoporotic fractures. The KFRS was able to predict risk of fracture in the primary population without bone mineral density testing and is therefore suitable for use in both clinical setting and self-assessment. The website is available at http://www.nhis.or.kr.

Hip fracture in hospitalized medical patients.

Science.gov (United States)

Zapatero, Antonio; Barba, Raquel; Canora, Jesús; Losa, Juan E; Plaza, Susana; San Roman, Jesús; Marco, Javier

2013-01-08

The aim of the present study is to analyze the incidence of hip fracture as a complication of admissions to internal medicine units in Spain. We analyzed the clinical data of 2,134,363 adults who had been admitted to internal medicine wards. The main outcome was a diagnosis of hip fracture during hospitalization.Outcome measures included rates of in-hospital fractures, length of stay and cost. A total of 1127 (0.057%) admittances were coded with an in-hospital hip fracture. In hospital mortality rate was 27.9% vs 9.4%; p patients with a hip fracture (20.7 days vs 9.8 days; p hip-fracture patients (6927€ per hospitalization vs 3730€ in non fracture patients). Risk factors related to fracture were: increasing age by 10 years increments (OR 2.32 95% CI 2.11-2.56), female gender (OR 1.22 95% CI 1.08-1.37), admission from nursing home (OR 1.65 95% CI 1.27-2.12), dementia (1.55 OR 95% CI1.30-1.84), malnutrition (OR 2.50 95% CI 1.88-3.32), delirium (OR 1.57 95% CI 1.16-2.14), and anemia (OR 1.30 95%CI 1.12-1.49). In-hospital hip fracture notably increased mortality during hospitalization, doubling the mean length of stay and mean cost of admission. These are reasons enough to stress the importance of designing and applying multidisciplinary plans focused on reducing the incidence of hip fractures in hospitalized patients.

Ipsilateral femoral neck and shaft fractures: An overlooked association

International Nuclear Information System (INIS)

Daffner, R.H.; Riemer, B.L.; Butterfield, S.L.

1991-01-01

A total of 304 patients with injuries to the femoral shaft and ipsilateral hip presented between 1984 and 1990. Some 253 of them suffered fractures of the femoral shaft and dislocated hips or fractures of the acetabulum, and 51 of these sustained fractures of the femoral shaft and neck or trochanteric region. All of the trochanteric injuries were demonstrated on the initial radiographs. However, in 11 of the patients with combined femoral shaft and neck fractures, the diagnosis was delayed by as much as 4 weeks. This delay related to the fact that these fractures tended not to separate in the initial evaluation period and that there was external rotation of the proximal femoral fragment due to the femoral shaft fracture. (orig./GDG)

Ipsilateral femoral neck and shaft fractures: An overlooked association

Energy Technology Data Exchange (ETDEWEB)

Daffner, R.H. (Dept. of Diagnostic Radiology, Allegheny General Hospital, Pittsburgh, PA (USA) Medical Coll. of Pennsylvania, Pittsburgh, PA (USA)); Riemer, B.L.; Butterfield, S.L. (Dept. of Orthopedic Surgery, Allegheny General Hospital, Pittsburgh, PA (USA) Medical Coll. of Pennsylvania, Pittsburgh, PA (USA))

1991-05-01

A total of 304 patients with injuries to the femoral shaft and ipsilateral hip presented between 1984 and 1990. Some 253 of them suffered fractures of the femoral shaft and dislocated hips or fractures of the acetabulum, and 51 of these sustained fractures of the femoral shaft and neck or trochanteric region. All of the trochanteric injuries were demonstrated on the initial radiographs. However, in 11 of the patients with combined femoral shaft and neck fractures, the diagnosis was delayed by as much as 4 weeks. This delay related to the fact that these fractures tended not to separate in the initial evaluation period and that there was external rotation of the proximal femoral fragment due to the femoral shaft fracture. (orig./GDG).

Comparison in bone turnover markers during early healing of femoral neck fracture and trochanteric fracture in elderly patients

Directory of Open Access Journals (Sweden)

Shota Ikegami

2009-10-01

Full Text Available Healing of fractures is different for each bone and bone turnover markers may reflect the fracture healing process. The purpose of this study was to determine the characteristic changes in bone turnover markers during the fracture healing process. The subjects were consecutive patients with femoral neck or trochanteric fracture who underwent surgery and achieved bone union. There were a total of 39 patients, including 33 women and 6 men. There were 18 patients (16 women and 2 men with femoral neck fracture and 21 patients (17 women and 4 men with trochanteric fracture. Serum bone-specific alkaline phosphatase (BAP was measured as a bone formation marker. Urine and serum levels of N-terminal telopeptide of type I collagen (NTX, as well as urine levels of C-terminal telopeptide of type I collagen (CTX and deoxypyridinoline (DPD, were measured as markers of bone resorption. All bone turnover markers showed similar changes in patients with either type of fracture, but significantly higher levels of both bone formation and resorption markers were observed in trochanteric fracture patients than in neck fracture patients. BAP showed similar levels at one week after surgery and then increased. Bone resorption markers were increased after surgery in patients with either fracture. The markers reached their peak values at three weeks (BAP and urinary NTX, five weeks (serum NTX and DPD, and 2-3 weeks (CTX after surgery. The increase in bone turnover markers after hip fracture surgery and the subsequent decrease may reflect increased bone formation and remodeling during the healing process. Both fractures had a similar bone turnover marker profile, but the extent of the changes differed between femoral neck and trochanteric fractures.

Comparison in bone turnover markers during early healing of femoral neck fracture and trochanteric fracture in elderly patients.

Science.gov (United States)

Ikegami, Shota; Kamimura, Mikio; Nakagawa, Hiroyuki; Takahara, Kenji; Hashidate, Hiroyuki; Uchiyama, Shigeharu; Kato, Hiroyuki

2009-10-10

Healing of fractures is different for each bone and bone turnover markers may reflect the fracture healing process. The purpose of this study was to determine the characteristic changes in bone turnover markers during the fracture healing process. The subjects were consecutive patients with femoral neck or trochanteric fracture who underwent surgery and achieved bone union. There were a total of 39 patients, including 33 women and 6 men. There were 18 patients (16 women and 2 men) with femoral neck fracture and 21 patients (17 women and 4 men) with trochanteric fracture. Serum bone-specific alkaline phosphatase (BAP) was measured as a bone formation marker. Urine and serum levels of N-terminal telopeptide of type I collagen (NTX), as well as urine levels of C-terminal telopeptide of type I collagen (CTX) and deoxypyridinoline (DPD), were measured as markers of bone resorption. All bone turnover markers showed similar changes in patients with either type of fracture, but significantly higher levels of both bone formation and resorption markers were observed in trochanteric fracture patients than in neck fracture patients. BAP showed similar levels at one week after surgery and then increased. Bone resorption markers were increased after surgery in patients with either fracture. The markers reached their peak values at three weeks (BAP and urinary NTX), five weeks (serum NTX and DPD), and 2-3 weeks (CTX) after surgery. The increase in bone turnover markers after hip fracture surgery and the subsequent decrease may reflect increased bone formation and remodeling during the healing process. Both fractures had a similar bone turnover marker profile, but the extent of the changes differed between femoral neck and trochanteric fractures.

Cone-beam CT in diagnosis of scaphoid fractures

Energy Technology Data Exchange (ETDEWEB)

Edlund, Rolf; Lapidus, Gunilla; Baecklund, Jenny [Capio St Goeran' s Hospital, Department of Radiology, Stockholm (Sweden); Skorpil, Mikael [Karolinska University Hospital, Department of Radiology, Stockholm (Sweden); Karolinska Institutet, Department of Molecular Medicine and Surgery, Stockholm (Sweden)

2016-02-15

This prospective study investigated the sensitivity of cone beam computed tomography (CBCT), a low dose technique recently made available for extremity examinations, in detecting scaphoid fractures. Magnetic resonance imaging (MRI) was used as gold standard for scaphoid fractures. A total of 95 patients with a clinically suspected scaphoid fracture were examined with radiography and CBCT in the acute setting. A negative CBCT exam was followed by an MRI within 2 weeks. When a scaphoid fracture was detected on MRI a new CBCT was performed. Radiography depicted seven scaphoid fractures, all of which were also seen with CBCT. CBCT detected another four scaphoid fractures. With MRI another five scaphoid fractures were identified that were not seen with radiography or with CBCT. These were also not visible on the reexamination CBCT. Sensitivity for radiography was 44, 95 % confidence interval 21-69 %, and for CBCT 69 %, 95 % confidence interval 41-88 % (p = 0.12). Several non-scaphoid fractures in the carpal region were identified, radiography and CBCT depicted 7 and 34, respectively (p < 0.0001). CBCT is a superior alternative to radiography, entailing more accurate diagnoses of carpal region fractures, and thereby requiring fewer follow-up MRI examinations. However, CBCT cannot be used to exclude scaphoid fractures, since MRI identified additional occult scaphoid fractures. (orig.)

Selective perceptions of hydraulic fracturing.

Science.gov (United States)

Sarge, Melanie A; VanDyke, Matthew S; King, Andy J; White, Shawna R

2015-01-01

Hydraulic fracturing (HF) is a focal topic in discussions about domestic energy production, yet the American public is largely unfamiliar and undecided about the practice. This study sheds light on how individuals may come to understand hydraulic fracturing as this unconventional production technology becomes more prominent in the United States. For the study, a thorough search of HF photographs was performed, and a systematic evaluation of 40 images using an online experimental design involving N = 250 participants was conducted. Key indicators of hydraulic fracturing support and beliefs were identified. Participants showed diversity in their support for the practice, with 47 percent expressing low support, 22 percent high support, and 31 percent undecided. Support for HF was positively associated with beliefs that hydraulic fracturing is primarily an economic issue and negatively associated with beliefs that it is an environmental issue. Level of support was also investigated as a perceptual filter that facilitates biased issue perceptions and affective evaluations of economic benefit and environmental cost frames presented in visual content of hydraulic fracturing. Results suggested an interactive relationship between visual framing and level of support, pointing to a substantial barrier to common understanding about the issue that strategic communicators should consider.

Elastic scattering and total cross section at very high energies

International Nuclear Information System (INIS)

Castaldi, R.; Sanguinetti, G.

1985-01-01

The aim of this review is to summarize the recent progress in the field of elastic scattering and total cross section in this new energy domain. In Section 2 a survey of the experimental situation is outlined. The most significant data are presented, with emphasis on the interpretation, not the specific details or technicalities. This section is therefore intended to give a self-contained look at the field, especially for the nonspecialist. In Section 3, hadron scattering at high energy is described in an impact parameter picture, which provides a model-independent intuitive geometrical representation. The diffractive character of elastic scattering, seen as the shadow of inelastic absorption, is presented as a consequence of unitarity in the s-channel. Spins are neglected throughout this review, inasmuch as the asymptotic behavior in the very high-energy limit is the main concern here. In Section 4 some relevant theorems are recalled on the limiting behavior of hadron-scattering amplitudes at infinite energy. There is also a brief discussion on how asymptotically rising total cross sections imply scaling properties in the elastic differential cross sections. A quick survey of eikonal models is presented and their predictions are compared with ISR and SPS Collider data

Experimental research on rock fracture failure characteristics under liquid nitrogen cooling conditions

Science.gov (United States)

Gao, Feng; Cai, Chengzheng; Yang, Yugui

2018-06-01

As liquid nitrogen is injected into a wellbore as fracturing fluid, it can rapidly absorb heat from warmer rock and generate cryogenic condition in downhole region. This will alter the physical conditions of reservoir rocks and further affect rock failure characteristics. To investigate rock fracture failure characteristics under liquid nitrogen cooling conditions, the fracture features of four types of sandstones and one type of marble were tested on original samples (the sample without any treatment) and cryogenic samples (the samples just taken out from the liquid nitrogen), respectively. The differences between original samples and cryogenic samples in load-displacement curves, fracture toughness, energy evolution and the crack density of ruptured samples were compared and analyzed. The results showed that at elastic deformation stage, cryogenic samples presented less plastic deformation and more obvious brittle failure characteristics than original ones. The average fracture toughness of cryogenic samples was 10.47%-158.33% greater than that of original ones, indicating that the mechanical strength of rocks used were enhanced under cooling conditions. When the samples ruptured, the cryogenic ones were required to absorb more energy and reserve more elastic energy. In general, the fracture degree of cryogenic samples was higher than that of original ones. As the samples were entirely fractured, the crack density of cryogenic samples was about 536.67% at most larger than that of original ones. This indicated that under liquid nitrogen cooling conditions, the stimulation reservoir volume is expected to be improved during fracturing. This work could provide a reference to the research on the mechanical properties and fracture failure of rock during liquid nitrogen fracturing.

Optimization of flow modeling in fractured media with discrete fracture network via percolation theory

Science.gov (United States)

Donado-Garzon, L. D.; Pardo, Y.

2013-12-01

Fractured media are very heterogeneous systems where occur complex physical and chemical processes to model. One of the possible approaches to conceptualize this type of massifs is the Discrete Fracture Network (DFN). Donado et al., modeled flow and transport in a granitic batholith based on this approach and found good fitting with hydraulic and tracer tests, but the computational cost was excessive due to a gigantic amount of elements to model. We present in this work a methodology based on percolation theory for reducing the number of elements and in consequence, to reduce the bandwidth of the conductance matrix and the execution time of each network. DFN poses as an excellent representation of all the set of fractures of the media, but not all the fractures of the media are part of the conductive network. Percolation theory is used to identify which nodes or fractures are not conductive, based on the occupation probability or percolation threshold. In a fractured system, connectivity determines the flow pattern in the fractured rock mass. This volume of fluid is driven through connection paths formed by the fractures, when the permeability of the rock is negligible compared to the fractures. In a population of distributed fractures, each of this that has no intersection with any connected fracture do not contribute to generate a flow field. This algorithm also permits us to erase these elements however they are water conducting and hence, refine even more the backbone of the network. We used 100 different generations of DFN that were optimized in this study using percolation theory. In each of the networks calibrate hydrodynamic parameters as hydraulic conductivity and specific storage coefficient, for each of the five families of fractures, yielding a total of 10 parameters to estimate, at each generation. Since the effects of the distribution of fault orientation changes the value of the percolation threshold, but not the universal laws of classical

Fracture mechanics parameters for glasses: A compilation and correlation

International Nuclear Information System (INIS)

Freiman, S.W.; Baker, T.L.; Wachtmann, J.B.

1985-01-01

This paper describes a computerized fracture mechanics data base and associated computer programs which permit extension and modification of data base as well as selection, plotting and curve fitting. Some preliminary results of correlations of fracture energy, gamma, with composition and elastic modulus are presented

Managing total corporate electricity/energy market risks

International Nuclear Information System (INIS)

Henney, A.; Keers, G.

1998-01-01

The banking industry has developed a tool kit of very useful value at risk techniques for hedging risk, but these techniques must be adapted to the special complexities of the electricity market. This paper starts with a short history of the use of value-at-risk (VAR) techniques in banking risk management and then examines the specific and, in many instances, complex risk management challenges faced by electric companies from the behavior of prices in electricity markets and from the character of generation and electric retailing risks. The third section describes the main methods for making VAR calculations along with an analysis of their suitability for analyzing the risks of electricity portfolios and the case for using profit at risk and downside risk as measures of risk. The final section draws the threads together and explains how to look at managing total corporate electricity market risk, which is a big step toward managing total corporate energy market risk

Use of DXA-Based Structural Engineering Models of the Proximal Femur to Discriminate Hip Fracture

Science.gov (United States)

Yang, Lang; Peel, Nicola; Clowes, Jackie A; McCloskey, Eugene V; Eastell, Richard

2011-01-01

Several DXA-based structural engineering models (SEMs) of the proximal femur have been developed to estimate stress caused by sideway falls. Their usefulness in discriminating hip fracture has not yet been established and we therefore evaluated these models. The hip DXA scans of 51 postmenopausal women with hip fracture (30 femoral neck, 17 trochanteric, and 4 unspecified) and 153 age-, height-, and weight-matched controls were reanalyzed using a special version of Hologic’s software that produced a pixel-by-pixel BMD map. For each map, a curved-beam, a curved composite-beam, and a finite element model were generated to calculate stress within the bone when falling sideways. An index of fracture risk (IFR) was defined over the femoral neck, trochanter, and total hip as the stress divided by the yield stress at each pixel and averaged over the regions of interest. Hip structure analysis (HSA) was also performed using Hologic APEX analysis software. Hip BMD and almost all parameters derived from HSA and SEM were discriminators of hip fracture on their own because their ORs were significantly >1. Because of the high correlation of total hip BMD to HSA and SEM-derived parameters, only the bone width discriminated hip fracture independently from total hip BMD. Judged by the area under the receiver operating characteristics curve, the trochanteric IFR derived from the finite element model was significant better than total hip BMD alone and similar to the total hip BMD plus bone width in discriminating all hip fracture and femoral neck fracture. No index was better than total hip BMD for discriminating trochanteric fractures. In conclusion, the finite element model has the potential to replace hip BMD in discriminating hip fractures. PMID:18767924

Fracture toughness of MgCr2O4-ZrO2 composities

International Nuclear Information System (INIS)

Singh, J.P.