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Sample records for external compression-induced fracture

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

    PubMed

    Dang, David

    2007-01-01

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

  2. 21 CFR 878.3250 - External facial fracture fixation appliance.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false External facial fracture fixation appliance. 878.3250 Section 878.3250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... External facial fracture fixation appliance. (a) Identification. An external facial fracture...

  3. 21 CFR 878.3250 - External facial fracture fixation appliance.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false External facial fracture fixation appliance. 878.3250 Section 878.3250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... External facial fracture fixation appliance. (a) Identification. An external facial fracture...

  4. 21 CFR 878.3250 - External facial fracture fixation appliance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External facial fracture fixation appliance. 878.3250 Section 878.3250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... External facial fracture fixation appliance. (a) Identification. An external facial fracture...

  5. Description of Fracture Systems for External Criticality Reports

    SciTech Connect

    Jean-Philippe Nicot

    2001-09-21

    The purpose of this Analysis/Model Report (AMR) is to describe probabilistically the main features of the geometry of the fracture system in the vicinity of the repository. They will be used to determine the quantity of fissile material that could accumulate in the fractured rock underneath a waste package as it degrades. This AMR is to feed the geochemical calculations for external criticality reports. This AMR is done in accordance with the technical work plan (BSC (Bechtel SAIC Company) 2001 b). The scope of this AMR is restricted to the relevant parameters of the fracture system. The main parameters of interest are fracture aperture and fracture spacing distribution parameters. The relative orientation of the different fracture sets is also important because of its impact on criticality, but they will be set deterministically. The maximum accumulation of material depends primarily on the fracture porosity, combination of the fracture aperture, and fracture intensity. However, the fracture porosity itself is not sufficient to characterize the potential for accumulation of a fracture system. The fracture aperture is also important because it controls both the flow through the fracture and the potential plugging of the system. Other features contributing to the void space such as lithophysae are also investigated. On the other hand, no analysis of the matrix porosity is done. The parameters will be used in sensitivity analyses of geochemical calculations providing actinide accumulations and in the subsequent Monte Carlo criticality analyses.

  6. Conversion from temporary external fixation to definitive fixation: shaft fractures.

    PubMed

    Dougherty, Paul J; Silverton, Craig; Yeni, Yener; Tashman, Scott; Weir, Robb

    2006-01-01

    Temporary external fixation is the most common method of initial stabilization of diaphyseal fractures in forward surgical hospitals. Once the patient arrives at a stable environment, usually the United States, the fracture is managed with intramedullary nailing, small-pin external fixation, or a modified external fixator. Future research should be directed toward improving methods of care. It is not precisely known when is the best time to convert to definitive fixation without increasing the risk of infection. The risk factors leading to infection and nonunion are not well-established, making that determination even more difficult. Clinical studies of a suitable size should provide insight into these problems. Although temporary external fixation is commonly used, an optimal construct has not been determined. Data from studies of in vivo fracture-site motion after application of the temporary external fixator should be compared with biomechanical testing of similar constructs. These data could be used to recommend optimal temporary external fixation constructs of tibia, femur, and humerus fractures using currently available devices as well as to provide groundwork for the next generation of fixators.

  7. 21 CFR 878.3250 - External facial fracture fixation appliance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false External facial fracture fixation appliance. 878.3250 Section 878.3250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices §...

  8. 21 CFR 878.3250 - External facial fracture fixation appliance.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false External facial fracture fixation appliance. 878.3250 Section 878.3250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices §...

  9. Treatment results of bicondylar tibial fractures using hybrid external fixator.

    PubMed

    Sales, Jafar Ganjpour; Soleymaopour, Jafar; Ansari, Maroof; Afaghi, Farhad; Goldust, Mohamad

    2013-05-15

    Tibial condyle fractures affect knee stability and motion. Treatment of bicondylar type of tibial plateau fracture is a challenging problem. This study aimed at evaluating the application of hybrid external fixators with minimum deformation in these patients and the resulted outcomes. In this descriptive analytical study, 28 patients with bicondylar tibial plateau fractures treated by HEF device were evaluated. The surgeon used a semicircular and one circular wire instead of the one or two loop of conventional HEF device for a better range of motion of the knee joint. Treatment outcomes including quality of walking, union condition, knee range of motion, complications and the final outcome according to the knee score (rusmussen) were checked. Twenty-eight male patients, with the mean age of 40.54 +/- 13.83 years were enrolled in the study. Complications occurred in 8 (28.6%) patients; 7 cases with superficial infection and 1 patient with deep vein thrombosis. All complications were managed medically with no significant consequences left. All the patients were able to walk with no aid except in one case. In 96.4% and 89.3% of the cases, the clinical and radiological outcomes were good to excellent, respectively according to the knee score. In 85.7% of the patients, the knee range of motion was in normal limits. Application of hybrid external fixator using one and half ring instead of one or two fixator rings in treating bicondylar tibial fractures was associated with desired clinical and radiological results.

  10. Clinical application of an external fixator in the repair of bone fractures in 28 birds.

    PubMed

    Hatt, J-M; Christen, C; Sandmeier, P

    2007-02-10

    The repair of seven tibiotarsal fractures, three humeral fractures, three tarsometatarsal fractures, two femoral fractures and 13 radial and ulnar fractures with a tubular external fixator system was evaluated prospectively in 10 common pigeons (Columba livia), 11 psittacine birds, six birds of prey and one Bali starling (Leucopsar rothschildii). The fixations included type 1, type 2 and intramedullary tie-in methods, and the fractures healed in all but three cases. A comparison of the weight of different connecting bars showed that the external fixation system and polymethylmethacrylate are the lightest available systems and that there was no clinically relevant difference between them.

  11. The role of external fixation and emergency fracture management in bovine orthopedics.

    PubMed

    Adams, S B

    1985-03-01

    External fixation is a very useful method of treating selected fractures in cattle. The economics of therapy and the availability of the techniques to all veterinarians will continue to make external fixation the most frequently used method of fracture repair in cattle.

  12. Hinged external fixation for Regan-Morrey type I and II fractures and fracture-dislocations.

    PubMed

    Castelli, Alberto; D'amico, Salvatore; Combi, Alberto; Benazzo, Francesco

    2016-06-01

    Elbow fracture-dislocation is always demanding to manage due to the considerable soft-tissue swelling or damage involved, which can make an early open approach and ligamentous reconstruction impossible. The purpose of this study was to evaluate the role of elbow hinged external fixation (HEF) as a definitive treatment in patients with elbow dislocations associated with Regan-Morrey (R-M) type I and II coronoid fractures and soft-tissue damage. We treated 11 patients between 2010 and 2012 with HEF. Instability tests and standard X-ray examinations were performed before surgery and 1-3 to 3-6 months after surgery, respectively. All patients underwent a preoperative CT scan. Outcomes were assessed with a functional assessment scale (Mayo Elbow Performance Score, MEPS) that included 4 parameters: pain, ROM, stability, and function. The results were good or excellent in all 11 patients, and no patient complained of residual instability. Radiographic examination showed bone metaplasia involving the anterior and medial sides of the joint in 5 patients. HEF presented several advantages: it improves elbow stability and it avoids long and demanding surgery in particular in cases with large soft tissue damage. We therefore consider elbow HEF to be a viable option for treating R-M type I and II fracture-dislocations.

  13. Clinical analysis of the rap stress stimulator applied for crus fracture after skeletal external fixation

    PubMed Central

    Zhuang, Ping; Hong, Jiayuan; Chen, Wei; Wu, Jin

    2015-01-01

    Introduction Open crus fracture is still difficult in clinical treatment because of the delayed fracture union and high rate of nonunion after the operation. A consensus has been reached that mechanical stress can promote fracture healing. We independently developed a stress stimulator, which can provide longitudinal pressure for the fixed fracture end of the lower legs to promote fracture healing. The purpose of this study is to explore the advantages and clinical effect of the rap stress stimulator applied for open crus fracture after skeletal external fixation. Material and methods One hundred and sixty-five patients (183 limbs) who suffered from open tibia and fibula fracture received skeletal external fixation, of which 108 limbs were treated with the rap stress stimulator after external fixation and 75 limbs were treated with regular functional exercises of muscle contraction and joint activity only. Then the fracture healing time and rate of nonunion were compared between the two groups. Results The mean fracture healing time and rate of nonunion in the group treated with the rap stress stimulator were 138.27 ±4.45 days and 3.70% respectively, compared to 153.43 ±4.89 days and 10.67% in the group treated without the stimulator. Conclusions The rap stress stimulator significantly shortened the fracture healing time and reduced the rate of nonunion for treating open tibia and fibula fractures. PMID:26170856

  14. Treatment of fractures of the tibia and radius-ulna by external coaptation.

    PubMed

    Adams, S B; Fessler, J F

    1996-03-01

    External coaptation of radial-ulnar and tibial fractures with casts or modified Thomas splint-cast combinations is a useful treatment. The economics of therapy make this method of treatment feasible for commercial animals. Current estimates for the cost of treatment of tibial fractures with Thomas splint-cast combinations are $225.00 for calves and $410.00 for cattle if the metal splints are reused. Casts have similar costs. The availability of external coaptation techniques to all veterinarians and the success of treatment make external coaptation a good method for the treatment of many tibial and radial-ulnar fractures in cattle.

  15. Predicting the external formation of callus tissues in oblique bone fractures: idealised and clinical case studies.

    PubMed

    Comiskey, D; MacDonald, B J; McCartney, W T; Synnott, K; O'Byrne, J

    2013-11-01

    It is proposed that the external asymmetric formation of callus tissues that forms naturally about an oblique bone fracture can be predicted computationally. We present an analysis of callus formation for two cases of bone fracture healing: idealised and subject-specific oblique bone fractures. Plane strain finite element (FE) models of the oblique fractures were generated to calculate the compressive strain field experienced by the immature callus tissues due to interfragmentary motion. The external formations of the calluses were phenomenologically simulated using an optimisation style algorithm that iteratively removes tissue that experiences low strains from a large domain. The resultant simulated spatial formation of the healing tissues for the two bone fracture cases showed that the calluses tended to form at an angle equivalent to the angle of the oblique fracture line. The computational results qualitatively correlated with the callus formations found in vivo. Consequently, the proposed methods show potential as a means of predicting callus formation in pre-clinical testing.

  16. Tibiotarsal fracture repair in a scarlet macaw using external skeletal fixation.

    PubMed

    Kavanagh, M

    1997-07-01

    Surgical repair of a fractured tibiotarsus in a scarlet macaw (Ara macao) is described. The forces imposed on the fracture site are discussed and the unique features of avian bone emphasised. Advantages of external skeletal fixation and specific details of the frame construction are highlighted.

  17. Optimal Treatment of Malignant Long Bone Fracture: Influence of Method of Repair and External Beam Irradiation on the Pathway and Efficacy of Fracture Healing

    DTIC Science & Technology

    2014-10-01

    Long Bone Fracture: Influence of Method of Repair and External Beam Irradiation on the Pathway and Efficacy of Fracture Healing 5a. CONTRACT NUMBER...in the fifth quarter of the award. 15. SUBJECT TERMS Fracture healing , bone healing , endochondral ossification, intramembranous ossification...irradiation, radiotherapy, pathologic fractures, bony metastasis, bone cancer, animal model , rat model 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF

  18. Treatment of Palatal Fractures by Osteosynthesis with 2.0-mm Locking Plates as External Fixator

    PubMed Central

    Cienfuegos, Ricardo; Sierra, Eduardo; Ortiz, Benjamin; Fernández, Gerardo

    2010-01-01

    Treatment options for palatal fractures range from orthodontic braces, acrylic bars, and arch bars for maxillomandibular fixation to internal fixation, with plates and screws placed under the palate mucosa and periosteum, together with pyriform aperture or alveolar plating plus buttress reconstruction. Forty-five patients, ages 4 to 56, were treated using medium- or high-profile locking plates placed over the palatal mucosa as an external fixator for palatal fractures, together with treatment for other associated facial fractures. In open fractures, plates were placed after approximating the edges of the mucosal wounds. Plates and screws for palate fixation were removed at 12 weeks, when computed tomography scans provided evidence of fracture healing. All palatal fractures healed by 12 weeks, with no cases of mucosal necrosis, bone exposure, fistulae, or infections. This approach achieves adequate stability, reduces the risk of bone and mucosal necrosis, and promotes healing of mucosal wounds in case of open fractures. PMID:22132261

  19. Secondary displacement of distal radius fractures treated by bridging external fixation.

    PubMed

    Farah, N; Nassar, L; Farah, Z; Schuind, F

    2014-05-01

    Loss of reduction remains an important problem after treatment of distal radius fractures, whatever the type of bone fixation. We assessed retrospectively the rate of secondary displacement after external fixation of distal radius fractures in order to identify possible risk factors for instability. We reviewed the pre-operative and serial post-operative radiographs of a retrospective series of 35 distal radius fractures treated by bridging external fixation. When classified according to the Société Française d'Orthopédie et Traumatologie (SOFCOT) criteria, the rate of secondary displacement was 48.5%. At final follow up, the reduction was anatomical in 12% and acceptable in 83%. There was malunion in 5%. The loss of reduction concerned primarily the distal radius palmar tilt and was moderate. No correlation was found with age, gender, type of fracture, degree of initial displacement, associated ulnar fracture, or seniority of the treating surgeon.

  20. Ingenious method of external fixator use to maintain alignment for nailing a proximal tibial shaft fracture.

    PubMed

    Behera, Prateek; Aggarwal, Sameer; Kumar, Vishal; Kumar Meena, Umesh; Saibaba, Balaji

    2015-09-01

    Fractures of the tibia are one of the most commonly seen orthopedic injuries. Most of them result from a high velocity trauma. While intramedullary nailing of tibial diaphyseal fractures is considered as the golden standard form of treatment for such cases, many metaphyseal and metaphyseal-diaphyseal junction fractures can also be managed by nailing. Maintenance of alignment of such fractures during surgical procedure is often challenging as the pull of patellar tendon tends to extend the proximal fragment as soon as one flexes the knee for the surgical procedure. Numerous technical modifications have been described in the literature for successfully nailing such fractures including semi extended nailing, use of medial plates and external fixators among others. In this study, it was aimed to report two cases in which we used our ingenious method of applying external fixator for maintaining alignment of the fracture and aiding in the entire process of closed intramedullary nailing of metaphyseal tibial fractures by the conventional method. We were able to get good alignment during and after the closed surgery as observed on post-operative radiographs and believe that further evaluation of this technique may be of help to surgeons who want to avoid other techniques.

  1. Emergency department external fixation for provisional treatment of pilon and unstable ankle fractures

    PubMed Central

    Lareau, Craig R.; Daniels, Alan H.; Vopat, Bryan G.; Kane, Patrick M.

    2015-01-01

    Unstable ankle fractures and impacted tibial pilon fractures often benefit from provisional external fixation as a temporizing measure prior to definitive fixation. Benefits of external fixation include improved articular alignment, decreased articular impaction, and soft tissue rest. Uniplanar external fixator placement in the Emergency Department (ED ex-fix) is a reliable and safe technique for achieving ankle reduction and stability while awaiting definitive fixation. This procedure involves placing transverse proximal tibial and calcaneal traction pins and connecting the pins with two external fixator rods. This technique is particularly useful in austere environments or when the operating room is not immediately available. Additionally, this bedside intervention prevents the patient from requiring general anesthesia and may be a cost-effective strategy for decreasing valuable operating time. The ED ex-fix is an especially valuable procedure in busy trauma centers and during mass casualty events, in which resources may be limited. PMID:25709258

  2. Treatment of acute and chronic elbow instability with a hinged external fixator after fracture dislocation.

    PubMed

    Zilkens, Christoph; Graf, Markus; Anastasiadis, Alexandros; Smajic, Samir; Muhr, Gert; Kälicke, Thomas

    2009-04-01

    This is a retrospective analysis of the clinical and radiological outcome in 24 patients with acute or chronic posttraumatic elbow instability, who were treated with open reduction, internal fixation and a hinged external fixator. The instability was acute after elbow fracture dislocation in 11 cases; the other 13 had chronic posttraumatic instability of the elbow. Concentric stability and a sufficient range of motion of the elbow joint were achieved in all cases. The addition of a hinged external fixator in noncompliant patients, who underwent open reduction and internal fixation of an acute or chronic posttraumatic unstable elbow, allows early intensive mobilisation and can improve the clinical outcome after these complex elbow injuries.

  3. Fracture Toughness Evaluation of Space Shuttle External Tank Thermal Protection System Polyurethane Foam Insulation Materials

    NASA Technical Reports Server (NTRS)

    McGill, Preston; Wells, Doug; Morgan, Kristin

    2006-01-01

    Experimental evaluation of the basic fracture properties of Thermal Protection System (TPS) polyurethane foam insulation materials was conducted to validate the methodology used in estimating critical defect sizes in TPS applications on the Space Shuttle External Fuel Tank. The polyurethane foam found on the External Tank (ET) is manufactured by mixing liquid constituents and allowing them to react and expand upwards - a process which creates component cells that are generally elongated in the foam rise direction and gives rise to mechanical anisotropy. Similarly, the application of successive foam layers to the ET produces cohesive foam interfaces (knitlines) which may lead to local variations in mechanical properties. This study reports the fracture toughness of BX-265, NCFI 24-124, and PDL-1034 closed-cell polyurethane foam as a function of ambient and cryogenic temperatures and knitline/cellular orientation at ambient pressure.

  4. Anterior pre-tensioned external fixator for pelvic fractures and dislocations. Initial clinical series.

    PubMed

    Queipo-de-Llano, A; Lombardo-Torre, M; Leiva-Gea, A; Delgado-Rufino, F B; Luna-González, F

    2016-12-01

    In the treatment of unstable pelvic ring fractures, external fixators have the limitation of not adequately stabilizing the injured posterior elements. This article presents a novel and simple technique of temporary external fixation of the pelvic ring, able to produce compression of both the anterior and posterior pelvic elements. A curved flexible carbon-fiber rod is used, pre-tensioned before attachment to supra-acetabular Schanz screws. Although more extensive clinical experience is required, favorable preliminary results in a series of 13 patients with unstable pelvic fracture were encouraging: the aim of closing the posterior and anterior elements of the pelvic ring was achieved in all cases treated with this technique, and 12 patients survived. Radiological results were excellent in 3 cases and good in 9 cases. No major complications, such as secondary displacement, vertical re-displacement or deep infection, were observed. Mean operative time was 25min, compatible with emergency management.

  5. Bicondylar tibial plateau fractures treated with fine-wire circular external fixation.

    PubMed

    Ferreira, N; Marais, L C

    2014-04-01

    Bicondylar tibial plateau fractures are serious injuries to a major weight-bearing joint. These injuries are often associated with severe soft tissue injuries that complicate surgical management. We reviewed 54 consecutive patients who sustained bicondylar tibial plateau fractures that were treated with limited open reduction and cannulated screw fixation combined with fine-wire circular external fixation. Forty-six patients met the inclusion criteria of this retrospective review. Eight patients were excluded because they did not complete a minimum of 1-year follow-up. Thirty-six patients had Schatzker type-VI, and ten patients had Schatzker type-V fractures. All fractures were united without loss of reduction; there were no incidences of wound complications, osteomyelitis or septic arthritis. The average Knee Society Clinical Rating Score was 81.6, translating to good clinical results. Minor pin track infection was the most common complication encountered. This review concludes that fine-wire circular external fixation, combined with limited open reduction and cannulated screw fixation, consistently produces good functional results without serious complications.

  6. External Fixation Vs Orif in the Treatment of Bilateral Calcaneum Fracture

    PubMed Central

    Carluzzo, Fulvio; Longo, G.F.

    2015-01-01

    Introduction: The following is an original case report in the literature of a patient with post-traumatic bilateral calcaneum fracture, both type III of Sanders’ classification, that was treated, by the same surgeon, in the left foot with open reduction and internal fixation and in the right foot with closed reduction and application of an external fixator. Case Report: Patient 43 y.o., male, high fall accident, with bilateral calcaneum fracture, both type III of Sanders’ classification. we have chosen to treat the left foot with ORIF (Fig. 3) and the right one with closed reduction and application of an external fixator. Patient was followed up radiologically with radiographs at 2, 12 and 24 months, and clinically at 15 days, 1, 3, 6, 12, 18 and 24 months with the Maryland Foot Score, as suggested by Sanders et al. Conclusion: In our patient, the one year clinical outcomes post-surgery was better in the foot treated with external fixation, regardless complex fracture and the not good status of soft tissue, due to open surgical treatment and hardwere inside. Long-term clinical follow-up given best outcomes in patients treated with ORIF, due to better reduction of subtalar joint facet and Böhler’s angle. PMID:27299071

  7. Colles' fracture treated with non-bridging external fixation: a 1-year follow-up.

    PubMed

    Andersen, J K; Høgh, A; Gantov, J; Vaesel, M T; Hansen, T Baek

    2009-08-01

    The results in 75 of 105 patients with Older type II/III (AO type A2.2, A3.1, A3.2) Colles' fractures, treated with non-bridging external fixation are presented. The mean age was 67.8 years, and all patients were followed prospectively for 12 months with radiological and functional assessment. No statistically significant loss of radial length, angulation or inclination was seen between the postoperative reduction and the 1-year follow-up examination. The clinical results after 1 year were 66 (88%) excellent/good, nine (12%) fair and 0 (0%) poor according to the modified Gartland and Werley score. Mean visual analogue scale pain score after 1 year was 0.8. In three patients (4%), re-displacement of the fracture occurred and was treated with plating. Non-bridging external fixation offers a reliable method of maintaining radiological reduction of Older type II/III fractures of the distal radius and gives a good functional outcome after 1 year.

  8. External fixators for open fractures of tibia and fibula in patients with haemophilia A.

    PubMed

    Lin, J; Liu, H; Liu, P; Yang, H

    2015-01-01

    To evaluate the efficacy of external fixators(EFs) for management of open fractures of tibia and fibula in patients with haemophilia A. EFs are commonly used in the clinical management of infected or open fractures when internal fixation is contraindicated and plaster immobilization is inadequate. However, EFs have not been frequently used for these indications in haemophilic patients for fear of pin tract infection and bleeding. This is a retrospective therapeutic study. We describe the use of EF (Orthofix uniplanar fixators) in five patients (mean age: 31.4 years; range: 10-52) with haemophilia A suffering from open fracture of tibia and fibula (Gustilo classification ranging from II to IIIA). The average time to union was 23 weeks (range: 18-30 weeks). Much lower levels were subsequently maintained till wound healing. The average total factor consumption was 358.30 IU kg(-1) (range: 272-421 IU kg(-1) ), administered over a period of 14.2 days (range 9-21). There were no major complications related to EF. In summary, EFs can be used safely and effectively in management of open fractures of tibia and fibula in patients with haemophilia A.

  9. Long-term outcome after supination-external rotation type-4 fractures of the ankle.

    PubMed

    Stufkens, S A S; Knupp, M; Lampert, C; van Dijk, C N; Hintermann, B

    2009-12-01

    We have compared the results at a mean follow-up of 13 years (11 to 14) of two groups of supination-external rotation type-4 fractures of the ankle, in one of which there was a fracture of the medial malleolus and in the other the medial deltoid ligament had been partially or completely ruptured. Of 66 patients treated operatively between 1993 and 1997, 36 were available for follow-up. Arthroscopy had been performed in all patients pre-operatively to assess the extent of the intra-articular lesions. The American Orthopaedic Foot and Ankle Society hind-foot score was used for clinical evaluation and showed a significant difference in both the total and the functional scores (p < 0.05), but not in those for pain or alignment, in favour of the group with a damaged deltoid ligament (p < 0.05). The only significant difference between the groups on the short-form 36 quality-of-life score was for bodily pain, again in favour of the group with a damaged deltoid ligament. There was no significant difference between the groups in the subjective visual analogue scores or in the modified Kannus radiological score. Arthroscopically, there was a significant difference with an increased risk of loose bodies in the group with an intact deltoid ligament (p < 0.005), although there was no significant increased risk of deep cartilage lesions in the two groups. At a mean follow-up of 13 years after operative treatment of a supination-external rotation type-4 ankle fracture patients with partial or complete rupture of the medial deltoid ligament tended to have a better result than those with a medial malleolar fracture.

  10. TREATMENT OF POST-TRAUMATIC HUMERAL FRACTURES AND COMPLICATIONS USING THE OSTEOLINE® EXTERNAL FIXATOR: A TREATMENT OPTION

    PubMed Central

    de Azevedo, Marcos Coelho; de Azevedo, Gualter Maldonado; Hayashi, Alexandre Yoshio; Dourado Nascimento, Paulo Emilio

    2015-01-01

    To evaluate the results obtained from treatment of humeral shaft fractures and their complications using the Osteoline® uniplanar external fixator. Methods: The radiographic and functional results from 78 patients with humeral shaft fractures treated using the uniplanar external fixation technique were retrospectively assessed. The patients' ages ranged from 23 to 71 years, with a mean of 47 years. Male patients predominated (79%). Out of the 78 patients, 45 presented open fractures, 14 presented pseudarthrosis and six presented synthesis failure. There were no losses during the follow-up and all the patients were discharged after fracture consolidation and functional recovery. The results were evaluated based on the studies by Catagni, as good, fair or poor. Results: Fracture consolidation was observed in 98% of the cases treated with uniplanar external fixation. Only one pseudarthrosis case required conversion to rigid internal fixation and autologous bone grafting. At the end of the treatment, all the patients were discharged with consolidated fractures, without pain, and good limb function. Conclusion: The external fixation described in this paper was shown to be an efficient and safe method for treating humeral shaft fractures and their complications. It preserved the local biological status and enabled passive and active movement immediately after surgery. PMID:27027026

  11. Hinged external fixation for complex fracture-dislocation of the elbow in elderly people.

    PubMed

    Maniscalco, P; Pizzoli, A L; Renzi Brivio, L; Caforio, M

    2014-12-01

    The authors report their experience of treating complex elbow fracture-dislocations in elderly people, using a minimally-invasive approach with a new articulated external fixator that is associated with minimal internal fixation. The clinical results for 19 patients are presented according to outcome factors, such as range of motion, pain and function, rate and type of complications, and reoperation rate. The results indicate that this treatment strategy should be considered as a good alternative to other treatment options reported in the literature, including conservative treatment, ORIF with angular stable plates and total elbow arthroplasty.

  12. External Fixation Versus Open Reduction With Locked Volar Plating for Geriatric Distal Radius Fractures

    PubMed Central

    Lee, Daniel J.

    2014-01-01

    The optimal management of displaced dorsal radius fractures (DRFs) in older patients remains an issue of debate. Bridging external fixation is a well-accepted treatment modality for severely comminuted DRFs, while open reduction and internal fixation with locked volar plating has emerged as a promising alternative in recent years. The current body of randomized trials supports the trend toward locked volar plating, as it allows for quicker improvement in subjective and functional outcomes. There is no clear evidence to suggest that one technique carries significantly less complications than the other. Locked volar plating should be considered in patients for whom an accelerated functional recovery would be advantageous. Otherwise, both external fixation and locked volar plating provide good long-term clinical outcomes. PMID:25360346

  13. Internal Versus External Fixation for the Treatment of Distal Radial Fractures

    PubMed Central

    Zhang, Qingyu; Liu, Fanxiao; Xiao, Zhenyun; Li, Zhenfeng; Wang, Bomin; Dong, Jinlei; Han, Yong; Zhou, Dongsheng; Li, Jianmin

    2016-01-01

    Abstract Although a serious of meta-analyses have been published to compare the effects of internal versus external fixation (IF vs EF) for treating distal radial fractures (DRF), no consensus was obtained. By performing a systematic review of overlapping meta-analyses comparing IF versus EF for the treatment of distal radial fractures, we attempted to evaluate the methodology and reporting quality of these meta-analyses, interpret the source of discordant results, and therefore determine the dominant strategy for the treatment of distal radial fractures based on the best evidence currently. An electronic databases search was conducted in MEDLINE, Embase, and Cochrane library to retrieve meta-analyses comparing IF versus EF for treating DRF. Reference lists of relevant literatures were also screened manually to retrieve additional ones. Two investigators independently assessed the eligibility of retrieved articles using predefined inclusion and exclusion criteria. All characteristics as well as outcome variables including functional outcomes, range of motion, radiological results, and complication rates with relevant heterogeneity information presented in each included study were extracted. Heterogeneity was thought to be significant when I2 > 50%. We adopted the Oxford Levels of Evidence and the Assessment of Multiple Systematic Reviews (AMSTAR) Instrument to assess the methodological quality of every included study, and applied the Jadad decision algorithm to select studies with more likely reliable conclusions. A total of 8 studies met the inclusion criteria. The AMSTAR scores ranged from 5 to 9 with a median of 7.75. Following the Jadad algorithm, the meta-analyses with most reliable results can be selected based on the search strategies and application of selection. Finally, 2 meta-analyses with most RCTs and highest AMSTAR scores were selected in this systematic review of overlapping meta-analysis. The best available evidence suggested that compared with

  14. Bone Healing by Using Ilizarov External Fixation Combined with Flexible Intramedullary Nailing versus Ilizarov External Fixation Alone in the Repair of Tibial Shaft Fractures: Experimental Study

    PubMed Central

    Popkov, A. V.; Kononovich, N. A.; Gorbach, E. N.; Tverdokhlebov, S. I.; Irianov, Y. M.; Popkov, D. A.

    2014-01-01

    Purpose. Our research was aimed at studying the radiographic and histological outcomes of using flexible intramedullary nailing (FIN) combined with Ilizarov external fixation (IEF) versus Ilizarov external fixation alone on a canine model of an open tibial shaft fracture. Materials and Methods. Transverse diaphyseal tibial fractures were modelled in twenty dogs. Fractures in the dogs of group 1 (n = 10) were stabilized with the Ilizarov apparatus while it was combined with FIN in group 2 (n = 10). Results. On day 14, a bone tissue envelope started developing round the FIN wires. Histologically, we revealed only endosteal bone union in group 1 while in group 2 the radiographs revealed complete bone union on day 28. At the same time-point, the areas of cancellous and mature lamellar bone tissues were observed in the intermediary area in group 2. The periosteal layers were formed of the trabeculae net of lamellar structure and united the bone fragments. The frame was removed at 30 days after the fracture in group 2 and after 45 days in group 1 according to bone regeneration. Conclusion. The combination of the Ilizarov apparatus and FIN accelerates bone repair and augments stabilization of tibial shaft fractures as compared with the use of the Ilizarov fixation alone. PMID:25379523

  15. Corrective supramalleolar osteotomy for malunited pronation-external rotation fractures of the ankle.

    PubMed

    Hintermann, B; Barg, A; Knupp, M

    2011-10-01

    We undertook a prospective study to analyse the outcome of 48 malunited pronation-external rotation fractures of the ankle in 48 patients (25 females and 23 males) with a mean age of 45 years (21 to 69), treated by realignment osteotomies. The interval between the injury and reconstruction was a mean of 20.2 months (3 to 98). In all patients, valgus malalignment of the distal tibia and malunion of the fibula were corrected. In some patients, additional osteotomies were performed. Patients were reviewed regularly, and the mean follow-up was 7.1 years (2 to 15). Good or excellent results were obtained in 42 patients (87.5%) with the benefit being maintained over time. Congruent ankles without a tilted talus (Takakura stage 0 and 1) were obtained in all but five cases. One patient required total ankle replacement.

  16. [Meaning of living with external fixation for grade III open fracture of lower limbs: patient view].

    PubMed

    Lopez, Catia Cristina Gomes; Gamba, Mônica Antar; Matheus, Maria Clara Cassuli

    2013-06-01

    The present study is aimed to understand the meaning of living with an external fixation device for grade III open fractures of the lower limbs from the perspective of the patient. The data were collected with six young adults who were undergoing outpatient orthopedic treatment in a public hospital in the city of São Paulo, through semi-structured interviews with open questions, between June and August 2010. Seeking to understand the meaning of this experience, we have maintained a phenomenological attitude during the analysis, which made it possible to reveal the phenomenon "try to live in spite of feeling trapped in a cage." Patients said that their personal desire and support from others helped them reorganize their lives, despite the several challenges they had to overcome to adapt to the fastener attached to their body and the fear of the future and doubts about the success of treatment.

  17. Malleolar fractures and their ligamentous injury equivalents have similar outcomes in supination-external rotation type IV fractures of the ankle treated by anatomical internal fixation.

    PubMed

    Berkes, M B; Little, M T M; Lazaro, L E; Sculco, P K; Cymerman, R M; Daigl, M; Helfet, D L; Lorich, D G

    2012-11-01

    It has previously been suggested that among unstable ankle fractures, the presence of a malleolar fracture is associated with a worse outcome than a corresponding ligamentous injury. However, previous studies have included heterogeneous groups of injury. The purpose of this study was to determine whether any specific pattern of bony and/or ligamentous injury among a series of supination-external rotation type IV (SER IV) ankle fractures treated with anatomical fixation was associated with a worse outcome. We analysed a prospective cohort of 108 SER IV ankle fractures with a follow-up of one year. Pre-operative radiographs and MRIs were undertaken to characterise precisely the pattern of injury. Operative treatment included fixation of all malleolar fractures. Post-operative CT was used to assess reduction. The primary and secondary outcome measures were the Foot and Ankle Outcome Score (FAOS) and the range of movement of the ankle. There were no clinically relevant differences between the four possible SER IV fracture pattern groups with regard to the FAOS or range of movement. In this population of strictly defined SER IV ankle injuries, the presence of a malleolar fracture was not associated with a significantly worse clinical outcome than its ligamentous injury counterpart. Other factors inherent to the injury and treatment may play a more important role in predicting outcome.

  18. Ilizarov hybrid external fixation for fractures of the distal radius: Part II. Internal fixation versus Ilizarov hybrid external fixation: Stability as assessed by cadaveric simulated motion testing.

    PubMed

    Dunning, C E; Lindsay, C S; Bicknell, R T; Johnson, J A; King, G J; Patterson, S D

    2001-03-01

    The in vitro stability of an Ilizarov hybrid external fixator was compared with that of a dorsal 3.5-mm AO T-plate in 8 unpaired, fresh-frozen upper extremities. A specially designed testing device that used computer-controlled pneumatic actuators was used to simulate active finger, wrist, and forearm motions by applying loads to relevant tendons. A comminuted extra-articular distal radius fracture was modelled using a dorsally based wedge osteotomy. Fracture stability was assessed using an electromagnetic tracking device to measure motion across the fracture site after randomized application of the plate and the hybrid fixator. During simulated finger and wrist motions with the forearm pronated or supinated, motion of the distal fragment with the hybrid fixator applied was comparable to or statistically less than with the AO plate applied. During simulated forearm rotation, the stability provided by the 2 fixation types was similar, although the plate allowed statistically less radial-ulnar deviation of the fragment. In this model of a 2-part extra-articular distal radius fracture, the clinically meaningful stability of the Ilizarov hybrid external fixator was comparable to that of the dorsal AO plate.

  19. Osteosynthesis in Distal Radius Fractures with Conventional Bridging External Fixator; Tips and Tricks for Getting Them Right

    PubMed Central

    Chilakamary, Vamshi Krishna; Koppolu, Kiran Kumar; Rapur, Shivaprasad

    2016-01-01

    Background Distal radius fractures are the commonest fractures occurring in the upper extremity, accounting for 15-20% of patients treated in emergency department. Although distal radial fractures were described 200 years ago, they still remain as unsolved fractures with no clear guidelines. It is often reported that anatomical reduction has a bearing on the functional outcome. Aim To study the management of distal end radius fracture by utilizing the principle of ligamentotaxis where in the reduction obtained by closed means is maintained by external fixator till solid bony union occurs. Materials and Methods A total of 26 cases were selected for study by scrutiny of the inclusion and exclusion criteria. Most of our cases were treated with external fixator within 8 hrs of injury. Small A.O external fixator (bridging ex-fix) with 2 pins each in radius and 2nd metacarpal percutaneously was used for all the cases. Selective k wire fixation was done in cases of instability. Fixator was removed after 6 weeks. Guided physiotherapy was ensured in all the cases. Patients were followed up for an average of 9 months. Results Modified Gartland and Werley scoring system was used to evaluate the overall functional results. Excellent to good results were achieved in 88.45% of our cases while fair result was in 11.54 %. One case had pin loosening and two other cases had malunion. Conclusion External fixator used for ligamentotaxis is an effective method of treating unstable extraarticular and complex intraarticular fractures of distal radius. Improved anatomical restoration with early rehabilitation has produced favourable functional outcome in our series. The complications like pin tract infection is rare due to the availability of superior antibiotics and sterile surgical technique. complications like wrist and finger stiffness has improved with physiotherapy. PMID:26894133

  20. The effect of HIV on early wound healing in open fractures treated with internal and external fixation.

    PubMed

    Aird, J; Noor, S; Lavy, C; Rollinson, P

    2011-05-01

    There are 33 million people worldwide currently infected with human immunodeficiency virus (HIV). This complex disease affects many of the processes involved in wound and fracture healing, and there is little evidence available to guide the management of open fractures in these patients. Fears of acute and delayed infection often inhibit the use of fixation, which may be the most effective way of achieving union. This study compared fixation of open fractures in HIV-positive and -negative patients in South Africa, a country with very high rates of both HIV and high-energy trauma. A total of 133 patients (33 HIV-positive) with 135 open fractures fulfilled the inclusion criteria. This cohort is three times larger than in any similar previously published study. The results suggest that HIV is not a contraindication to internal or external fixation of open fractures in this population, as HIV is not a significant risk factor for acute wound/implant infection. However, subgroup analysis of grade I open fractures in patients with advanced HIV and a low CD4 count (< 350) showed an increased risk of infection; we suggest that grade I open fractures in patients with advanced HIV should be treated by early debridement followed by fixation at an appropriate time.

  1. Numerical simulation research to both the external fixation surgery scheme of intertrochanteric fracture and the healing process, and its clinical application.

    PubMed

    Wang, Xian-Kang; Ye, Jin-Duo; Gu, Fu-Shun; Wang, Ai-guo; Zhang, Chun-Qiu; Tian, Qian-Qian; Li, Xue; Dong, Li-Min

    2014-01-01

    In this paper, the single arm external fixation of intertrochanteric fracture healing process after surgery was simulated to obtain a postoperative fracture healing and stress distribution in the external fixator. Firstly CT images of intertrochanteric fracture are reconstructed into the femur solid model. Then based, the external fixator is installed on the model, which lastly formed a finite element model of unilateral external fixation for intertrochanteric fracture. The calculated results show: during the beginning of the fracture healing, there is much higher stress in both screws and femur in the model with solid screws than that in the model with hollow screw. The stress of the femur in the model with hollow screw is more evenly. During the middle time of Fracture healing, stress in the femoral head significantly decreases. And the stress at fracture site gradually increased with the healing occurrence. According to the results, the authors designed hollow screws to use external fixation surgery. Surgery confirmed that the use of hollow screws in fractures treatment can satisfy the strength requirements, and can effectively reduce operative time, less patient suffering. The research for external fixation can provide a reference, and promote the use of external fixation hollow screws.

  2. Temporary Stabilization with External Fixator in ‘Tripolar’ Configuration in Two Steps Treatment of Tibial Pilon Fractures

    PubMed Central

    Daghino, Walter; Messina, Marco; Filipponi, Marco; Alessandro, Massè

    2016-01-01

    Background: The tibial pilon fractures represent a complex therapeutic problem for the orthopedic surgeon, given the frequent complications and outcomes disabling. The recent medical literature indicates that the best strategy to reduce amount of complications in tibial pilon fractures is two-stages procedure. We describe our experience in the primary stabilization of these fractures. Methods: We treated 36 cases with temporary external fixation in a simple configuration, called "tripolar": this is an essential structure (only three screws and three rods), that is possible to perform even without the availability of X-rays and with simple anesthesia or sedation. Results: We found a sufficient mechanical stability for the nursing post-operative, in absence of intraoperative and postoperative problems. The time between trauma and temporary stabilization ranged between 3 and 144 hours; surgical average time was 8.4 minutes. Definitive treatment was carried out with a delay of a minimum of 4 and a maximum of 15 days from the temporary stabilization, always without problems, both in case of ORIF (open reduction, internal fixation) or circular external fixation Conclusion: Temporary stabilization with external fixator in ‘tripolar’ configuration seems to be the most effective strategy in two steps treatment of tibial pilon fractures. These preliminary encouraging results must be confirmed by further studies with more cases. PMID:27123151

  3. Surgical stabilization for open tibial fractures in children: External fixation or elastic stable intramedullary nail - which method is optimal?

    PubMed Central

    Ramasubbu, Rohan A; Ramasubbu, Benjamin M

    2016-01-01

    Background: Management of open tibial fractures is well documented in adults, with existing protocols outlining detailed treatment strategies. No clear guidelines exist for children. Surgical stabilization of tibial fractures in the pediatric population requires implants that do not disrupt the open epiphyses (growth plate). Both elastic stable intramedullary nails and external fixation can be used. The objective of this study was to identify the optimal method of surgical stabilization in the treatment of open tibial fractures in children. Materials and Methods: MEDLINE and Embase were searched from their inception to March 2014 using the following advanced search terms (Key words): “open tibia fracture,” “fracture fixation,” “external fixation,” “intramedullary,” and “bone nail.” Only studies in English and pertaining to children with open fractures treated with elastic stable intramedullary nails or external fixation between 1994 and 2014 were included. Twelve clinical studies were critically appraised. Results: Due to a paucity in the literature coupled with a nonsystematic presentation of results, it proved to be very difficult in extracting relevant results from the studies. This was further added by a variation in outcome measures. Consequently, the results we obtained were difficult to draw conclusions from. Conclusion: There is no conclusive evidence or best practice guidelines for their management. Thus, as is highlighted in this study, more research is needed to determine the optimum treatment strategy for this common pediatric injury. The existing literature is of poor quality; consisting mainly of retrospective reviews of patients’ medical records, charts, and radiographs. Carefully designed, high-quality prospective cohort studies utilizing a nationalized multi-hospital approach are needed to improve understanding before protocols and guidelines can be developed and implemented. PMID:27746486

  4. [Complications of open reduction and internal fixation versus external fixation for unstable distal radius fractures: a meta-analysis].

    PubMed

    Yang, Z; Yuan, Z Z; Ma, J X; Ma, X L

    2016-12-20

    Objective: To make a systematic assessment of the complications of open reduction and internal fixation versus external fixation for unstable distal radius fractures. Method: A computer-based online search of PubMed, ScienceDirect, EMBASE, BIOSIS, Springer and Cochrane Library were performed.The randomized and controlled trials of open reduction and internal fixation versus external fixation for unstable distal radius fractures were collected.The included trials were screened out strictly based on the criterion of inclusion and exclusion.The quality of included trials was evaluated.RevMan 5.0 was used for data analysis. Result: A total of 17 studies involving 1 402 patients were included.There were 687 patients with open reduction and internal fixation and 715 with external fixation.The results of Meta-analysis indicated that there were statistically significant differences with regard to the postoperatively total complications, infection, malunion, tendon rupture (I(2)=8%, RR=0.77(95%CI 0.65-0.91, Z=3.10, P<0.05). There were no statistically significant differences observed between two approaches with respect to nounion, re-operation, complex regional pain syndrome, carpal tunnel syndrome, neurapraxia, tendonitis, painful hardware, scar(P>0.05). Conclusion: Postoperative complications are present in both open reduction and internal fixation and external fixation.Compared with external fixation, open reduction and internal fixation is lower in total complications postoperatively, infection and malunion, but external fixation has lower tendon rupture incidence.

  5. Use of a locking compression plate as an external fixator for repair of a tarsometatarsal fracture in a bald eagle (Haliaeetus leucocephalus).

    PubMed

    Montgomery, Ronald D; Crandall, Elizabeth; Bellah, Jamie R

    2011-06-01

    We describe the successful treatment of a tarsometatarsal fracture in a mature bald eagle (Haliaeetus leucocephalus) using a locking compression plate as an external fixator. The anatomy of the area (inelastic dermis and minimal subcutaneous space) and the high forces placed on a fracture at that site necessitated a unique approach to fixation. The unconventional use of a locking compression plate as an external fixator was minimally invasive, well tolerated by the eagle, and provided adequate stability in opposing fracture forces. This technique may serve as a method of fixation for tarsometatarsal fractures in other large avian species.

  6. Integrins mediate mechanical compression-induced endothelium-dependent vasodilation through endothelial nitric oxide pathway.

    PubMed

    Lu, Xiao; Kassab, Ghassan S

    2015-09-01

    Cardiac and skeletal muscle contraction lead to compression of intramuscular arterioles, which, in turn, leads to their vasodilation (a process that may enhance blood flow during muscle activity). Although endothelium-derived nitric oxide (NO) has been implicated in compression-induced vasodilation, the mechanism whereby arterial compression elicits NO production is unclear. We cannulated isolated swine (n = 39) myocardial (n = 69) and skeletal muscle (n = 60) arteriole segments and exposed them to cyclic transmural pressure generated by either intraluminal or extraluminal pressure pulses to simulate compression in contracting muscle. We found that the vasodilation elicited by internal or external pressure pulses was equivalent; moreover, vasodilation in response to pressure depended on changes in arteriole diameter. Agonist-induced endothelium-dependent and -independent vasodilation was used to verify endothelial and vascular smooth muscle cell viability. Vasodilation in response to cyclic changes in transmural pressure was smaller than that elicited by pharmacological activation of the NO signaling pathway. It was attenuated by inhibition of NO synthase and by mechanical removal of the endothelium. Stemming from previous observations that endothelial integrin is implicated in vasodilation in response to shear stress, we found that function-blocking integrin α5β1 or αvβ3 antibodies attenuated cyclic compression-induced vasodilation and NOx (NO(-)2 and NO(-)3) production, as did an RGD peptide that competitively inhibits ligand binding to some integrins. We therefore conclude that integrin plays a role in cyclic compression-induced endothelial NO production and thereby in the vasodilation of small arteries during cyclic transmural pressure loading.

  7. Stability-based classification for ankle fracture management and the syndesmosis injury in ankle fractures due to a supination external rotation mechanism of injury.

    PubMed

    Pakarinen, Harri

    2012-12-01

    sensitivity and specificity of both clinical tests were calculated using the standard 7.5-Nm external rotation stress test as reference. Outcome was assessed after a minimum of one year of follow-up. Olerud-Molander (OM) scoring system, RAND 36-Item Health Survey, and VAS to measure pain and function were used as outcome measures in all studies. In study 1, 85 (53%) fractures were treated operatively using the stability based fracture classification. Non-operatively treated patients reported less pain and better OM (good or excellent 89% vs. 71%) and VAS functional scores compared to operatively treated patients although they experienced more displacement of the distal fibula (0 mm 30% vs. 69%; 0-2 mm 65% vs. 25%) after treatment. No non-operatively treated patients required operative fracture fixation during follow-up. In study 2, AITFL exploration and suture lead to equal functional outcome (OM mean, 77 vs. 73) to no exploration or fixation. In study 3, the hook test had a sensitivity of 0.25 and a specificity of 0.98. The external rotation stress test had a sensitivity of 0.58 and a specificity of 0.9. Both tests had excellent interobserver reliability; the agreement was 99% for the hook test and 98% for the stress test. There was no statistically significant difference in functional scores (OM mean, 79.6 vs. 83.6) or pain between syndesmosis transfixation and no fixation groups (Study 4). Our results suggest that a simple stability-based fracture classification is useful in choosing between non-operative and operative treatment of ankle fractures; approximately half of the ankle fractures can be treated non-operatively with success. Our observations also suggest that relevant syndesmosis injuries are rare in ankle fractures due to an SER mechanism of injury. According to our research, syndesmotic repair or fixation in SER ankle fracture has no influence on functional outcome or pain after minimum one year compared with no fixation.

  8. [External femorotibial transfixation in femoral fracture with joint involvement in a child].

    PubMed

    Nounla, J; Bennek, J; Bühligen, U; Rolle, U

    2001-07-01

    Long bone fractures combined with joint injuries run a high risk of destabilising the articulations. Remaining joints incongruence can lead to early arthosis especially in cases of severe injuries or not achieved anatomical reduction. A number of osteosynthesis methods are available for anatomical repair of the articular facet. This report presents a seven years old boy with an open comminuted fracture of the distal femur and consecutive joint instability, treated with a Transfixation (Orthofix) of the knee joint. The functional results suggest this method as an alternative treatment.

  9. Manual Stress Ankle Radiography Has Poor Ability to Predict Deep Deltoid Ligament Integrity in a Supination External Rotation Fracture Cohort.

    PubMed

    Schottel, Patrick C; Fabricant, Peter D; Berkes, Marschall B; Garner, Matthew R; Little, Milton T M; Hentel, Keith D; Mintz, Douglas N; Helfet, David L; Lorich, Dean G

    2015-01-01

    Stress ankle radiographs are routinely performed to determine deep deltoid ligament integrity in supination external rotation (SER) ankle fractures. However, variability is present in the published data regarding what medial clear space (MCS) value constitutes a positive result. The purposes of the present study were to evaluate the diagnostic accuracy of different MCS cutoff values and determine whether this clinical test could accurately discriminate between patients with and without a deep deltoid ligament disruption. MCS measurements were recorded for stress ankle injury radiographs in an SER ankle fracture cohort. Preoperative ankle magnetic resonance imaging studies, obtained for all patients, were then read independently by 2 musculoskeletal attending radiologists to determine deep deltoid ligament integrity. The MCS measurements were compared with the magnetic resonance imaging diagnosis using receiver operating characteristic analyses to determine the sensitivity, specificity, and optimal data-driven cutoff values. SER II-III patients demonstrated a mean stress MCS distance of 4.3 ± 0.98 mm compared with 5.8 ± 1.76 mm in the SER IV cohort (p < .001). An analysis of differing MCS positive cutoff thresholds revealed that a stress MCS of 5.0 mm maximized the combined sensitivity and specificity of the external rotation test: 65.8% sensitive and 76.5% specific. Using the receiver operating characteristic curve analysis of the MCS measurement, the calculated area under the curve was 0.77, indicating inadequate discriminative ability for diagnosing SER pattern fractures with or without a deep deltoid ligament tear. Judicious use of additional diagnostic testing in patients with a stress MCS result between 4.0 mm and 5.5 mm is warranted.

  10. External fixation is more suitable for intra-articular fractures of the distal radius in elderly patients

    PubMed Central

    Ma, Chuang; Deng, Qiang; Pu, Hongwei; Cheng, Xinchun; Kan, Yuhua; Yang, Jing; Yusufu, Aihemaitijiang; Cao, Li

    2016-01-01

    The purpose of this study was to compare the functional outcomes, psychological impact, and complication rates associated with external fixation and volar or dorsal plating in relation to the functional parameters following treatment of intra-articular fractures of the distal radius (IFDR) in patients older than 65 years. We hypothesized that using volar or dorsal plating would improve functional outcomes, but that it would be associated with more complications and equivalent functional outcomes when compared with the external fixation group. A total of 123 consecutive patients suffering from IFDR were recruited into the study. The patients were measured for clinical, radiological, and psychosocial functioning outcomes and were followed up after 1 week and 3, 6 and 12 months. After 3 months, the plating group had better pronation (P=0.001), supination, (P=0.047) and extension (P=0.043) scores. These differences were somewhat attenuated by 6 months and disappeared at 1 year. The plating group had a greater occurrence of wound infection (P=0.043), tendonitis, (P=0.024) and additional surgery compared with the external fixation group. The only TNO-AZL Adult Quality of Life scores in the plating group that were lower than those in the external fixation group were in the “gross motor” category (walking upstairs, bending over, walking 500 yards; P=0.023). Internal fixation was more advantageous than external fixation in the early rehabilitation period; after 1 year the outcomes were similar. The plating group showed significantly higher levels of wound infection and tendonitis and had a greater need for additional surgeries. PMID:27408765

  11. Proximal screws placement in intertrochanteric fractures treated with external fixation: comparison of two different techniques

    PubMed Central

    2011-01-01

    Background To compare two different techniques of proximal pin placement for the treatment of intertrochanteric fractures in elderly patients utilizing the Orthofix Pertrochanteric Fixator. Methods Seventy elderly high-risk patients with an average age of 81 years were treated surgically for intertrochanteric fracture, resulting from a low energy trauma. Patients were randomly divided in two groups regarding to the proximal pin placement technique. In Group A the proximal pins were inserted in a convergent way, while in Group B were inserted in parallel. Results All fractures healed uneventfully after a mean time of 98 days. The fixator was well accepted and no patient had significant difficulties while sitting or lying. The mean VAS score was 5.4 in group A and 5.7 in group B. At 12 months after surgery, in group A the average Harris Hip Score and the Palmer and Parker mobility score was 67 and 5.8, respectively. In group B, the average Harris Hip Score and the Palmer and Parker mobility score was 62 and 5.6, respectively. No statistically significant difference was found regarding the functional outcome. The mean radiographic exposure during pin insertion in Group A and Group B was 15 and 6 seconds, respectively. The difference between the two groups, regarding the radiographic exposure, was found to be significant. Conclusion Proximal screw placement in a parallel way is simple, with significant less radiation exposure and shorter intraoperative duration. In addition, fixation stability is equal compared to convergent pin placement. PMID:21939534

  12. Osteonecrosis of the distal tibia after a pronation external rotation ankle fracture: literature review and management.

    PubMed

    Rajagopalan, S; Lloyd, J; Upadhyay, Vishal; Sangar, A; Taylor, H P

    2011-01-01

    Posttraumatic osteonecrosis of the distal tibia is a rare but recognized complication of Weber C ankle fractures. To our knowledge, we report the first documented case managed with early percutaneous drilling of the defect. The patient noticed an improvement in symptoms, and magnetic resonance imaging confirmed resolution of the avascular area. The previously reported complication of secondary periarticular collapse and subsequent osteoarthritis was avoided. We advocate that a high index of suspicion, early detection, and drilling can encourage neovascularisation and prevent secondary joint destruction.

  13. Incidence of Peroneal Tendinopathy After Application of a Posterior Antiglide Plate for Repair of Supination External Rotation Lateral Malleolar Fractures.

    PubMed

    Ahn, Jungtae; Kim, Sehun; Lee, Jung-Soo; Woo, Kyungjei; Sung, Ki-Sun

    2016-01-01

    Posterior antiglide plating is widely used to treat lateral malleolar fractures caused by supination-external rotation injuries. Despite its widespread use, this technique can be associated with postoperative peroneal tendinopathy. The purpose of the present observational review was to report the incidence of peroneal tendinopathy after the use of posterior antiglide plating to treat lateral malleolar fractures caused by a supination-external rotation injury. A total of 70 patients were followed up for a minimum of 12 (mean 55, range 12 to 109) months. Bony union was obtained in all cases after a mean of 57 (range 37 to 81) days. The median number of screw holes in the plate was 4.9 (range 4 to 7), and the median number of screws used to fixate the fibula was 6.58 (range 5 to 10). The mean American Orthopaedic Foot and Ankle Society hindfoot-ankle score at the final follow-up examination was 90.8 (range 55 to 100). Clinically, 3 (4.29%) of the 70 patients had lateral or posterolateral ankle pain indicative of peroneal tendinopathy after the index surgery, without any objective evidence. Of the 70 patients, 41 (58.57%) underwent surgical removal of the fibular hardware, 2 (4.87%) because of lateral ankle discomfort. At removal, inspection of the peroneal tendon sheath and/or tendons showed no gross evidence of tendinopathy in any of the patients. We concluded that the incidence of clinically evident peroneal tendon symptoms associated with posterior antiglide plating is low (4.3%), and direct operative inspection revealed no gross evidence of tendinopathy.

  14. Microcapsule Buckling Triggered by Compression-Induced Interfacial Phase Change.

    PubMed

    Salmon, Andrew Roy; Parker, Richard M; Groombridge, Alexander S; Maestro, Armando; Coulston, Roger J; Hegemann, Jonas; Kierfeld, Jan; Scherman, Oren A; Abell, Chris

    2016-10-04

    There is an emerging trend towards the fabrication of microcapsules at liquid interfaces. In order to control the parameters of such capsules, the interfacial processes governing their formation must be understood. Here, poly(vinyl alcohol) films are assembled at the interface of water-in-oil microfluidic droplets. The polymer is cross-linked using cucurbit[8]uril ternary supramolecular complexes. It is shown that compression-induced phase change causes the onset of buckling in the interfacial film. On evaporative compression, the interfacial film both increases in density and thickens, until it reaches a critical density and a phase change occurs. We show that this increase in density can be simply related to the film Poisson ratio and area compression. This description captures fundamentals of many compressive interfacial phase changes and can also explain the observation of a fixed thickness-to-radius ratio at buckling, (T/R)buck.

  15. Displaced Intra-Articular Fractures of the Distal Radius: Open Reduction With Internal Fixation Versus Bridging External Fixation

    PubMed Central

    Fakoor, Mohammad; Fakoor, Morteza; Mohammadhoseini, Payam

    2015-01-01

    Background: Distal radius fracture is common in all ages. Mobility and wrist function is important. The choice of treatment should aim for optimal function with minimal complications. Objectives: In this study we compared two surgical approaches, open reduction and internal fixation (ORIF) and closed reduction with external fixation (CR + EF), for treatment of intra-articular distal radius fractures. Patients and Methods: Ninety-four patients with distal radius fracture (type 3, 4 and 5 Fernandez classification) were treated with two surgical methods (ORIF and CR + EF); 55 were treated with CR + EF and 39 were treated with ORIF by different surgeons. All patients were assessed at the end of the first, third and sixth week; and then after the third, sixth and 12th month. At the end of the follow-up, all patients completed the Michigan hand outcome questionnaire (MHOQ). We compared radiological parameters of distal radius, range of motion (ROM) of the wrist, duration of rehabilitation, complication and patient satisfaction of the methods. Results: In our study, radiological findings for the ORIF group were radial inclination (RI): 19.35, radial length (RL): 10.35, radial tilt (RT): 8.92, and ulnar variance (UV): 1.64, while for the CR + EF group these were RI: 15.13, RL: 8, RT: 4.78, and UV: 0.27. The ROM for ORIF were flexion/extension (F/E): 137, Radial/Ulnar deviation (R/U): 52, and Supination/Pronation (S/P): 141, while for the CR + EF group these were F/E: 117, R/U: 40 and S/P: 116. Michigan hand outcome score for ORIF was 75% and for Ext. fix was 60%. The rate of complication with the ORIF method was 58% and in Ext. fix this was 69%. The patients in CR + EF had more than the ORIF course of physiotherapy and rehabilitation. Conclusions: In comparison of ORIF and CR + EF, all results including functional score, clinical and radiologic criteria were in favor of the ORIF method while there were less complications with this method. We believe that ORIF is a better

  16. Fractures

    MedlinePlus

    A fracture is a break, usually in a bone. If the broken bone punctures the skin, it is called an open ... falls, or sports injuries. Other causes are low bone density and osteoporosis, which cause weakening of the ...

  17. Metaphyseal locking plate as a definitive external fixator for treating open tibial fractures--clinical outcome and a finite element study.

    PubMed

    Ma, Ching-Hou; Wu, Chin-Hsien; Tu, Yuan-Kun; Lin, Ting-Sheng

    2013-08-01

    We evaluated both the outcome of using a locking plate as a definitive external fixator for treating open tibial fractures and, using finite element analysis, the biomechanical performance of external and internal metaphyseal locked plates in treating proximal tibial fractures. Eight open tibial patients were treated using a metaphyseal locked plate as a low-profile definitive external fixator. Then, finite element models of internal (IPF) as well as two different external plate fixations (EPFs) for proximal tibial fractures were reconstructed. The offset distances from the bone surface to the EPFs were 6 cm and 10 cm. Both axial stiffness and angular stiffness were calculated to evaluate the biomechanical performance of these three models. The mean follow-up period was 31 months (range, 18-43 months). All the fractures united and the mean bone healing time was 37.5 weeks (range, 20-52 weeks). All patients had excellent or good functional results and were walking freely at the final follow-up. The finite element finding revealed that axial stiffness and angular stiffness decreased as the offset distance from the bone surface increased. Compared to the IPF models, in the two EPF models, axial stiffness decreased by 84-94%, whereas the angular stiffness decreased by 12-21%. The locking plate used as a definitive external fixator provided a high rate of union. While the locking plate is not totally rigid, it is clinically stable and may be advisable for stiffness reduction of plating constructs, thus promoting fracture healing by callus formation. Our patients experienced a comfortable clinical course, excellent knee and ankle joint motion, satisfactory functional results and an acceptable complication rate.

  18. Open tibial fractures grade IIIC treated successfully with external fixation, negative-pressure wound therapy and recombinant human bone morphogenetic protein 7.

    PubMed

    Babiak, Ireneusz

    2014-10-01

    The aim of the therapy in open tibial fractures grade III was to cover the bone with soft tissue and achieve healed fracture without persistent infection. Open tibial fractures grade IIIC with massive soft tissue damage require combined orthopaedic, vascular and plastic-reconstructive procedures. Negative-pressure wound therapy (NPWT), used in two consecutive cases with open fracture grade IIIC of the tibia diaphysis, healed extensive soft tissue defect with exposure of the bone. NPWT eventually allowed for wound closure by split skin graft within 21-25 days. Ilizarov external fixator combined with application of recombinant human bone morphogenetic protein-7 at the site of delayed union enhanced definitive bone healing within 16-18 months.

  19. External validation and comparison of three prediction tools for risk of osteoporotic fractures using data from population based electronic health records: retrospective cohort study

    PubMed Central

    Cohen-Stavi, Chandra; Leventer-Roberts, Maya; Balicer, Ran D

    2017-01-01

    Objective To directly compare the performance and externally validate the three most studied prediction tools for osteoporotic fractures—QFracture, FRAX, and Garvan—using data from electronic health records. Design Retrospective cohort study. Setting Payer provider healthcare organisation in Israel. Participants 1 054 815 members aged 50 to 90 years for comparison between tools and cohorts of different age ranges, corresponding to those in each tools’ development study, for tool specific external validation. Main outcome measure First diagnosis of a major osteoporotic fracture (for QFracture and FRAX tools) and hip fractures (for all three tools) recorded in electronic health records from 2010 to 2014. Observed fracture rates were compared to probabilities predicted retrospectively as of 2010. Results The observed five year hip fracture rate was 2.7% and the rate for major osteoporotic fractures was 7.7%. The areas under the receiver operating curve (AUC) for hip fracture prediction were 82.7% for QFracture, 81.5% for FRAX, and 77.8% for Garvan. For major osteoporotic fractures, AUCs were 71.2% for QFracture and 71.4% for FRAX. All the tools underestimated the fracture risk, but the average observed to predicted ratios and the calibration slopes of FRAX were closest to 1. Tool specific validation analyses yielded hip fracture prediction AUCs of 88.0% for QFracture (among those aged 30-100 years), 81.5% for FRAX (50-90 years), and 71.2% for Garvan (60-95 years). Conclusions Both QFracture and FRAX had high discriminatory power for hip fracture prediction, with QFracture performing slightly better. This performance gap was more pronounced in previous studies, likely because of broader age inclusion criteria for QFracture validations. The simpler FRAX performed almost as well as QFracture for hip fracture prediction, and may have advantages if some of the input data required for QFracture are not available. However, both tools require calibration

  20. Finite element analysis of a novel pin-sleeve system for external fixation of distal limb fractures in horses.

    PubMed

    Brianza, Stefano; Brighenti, Vittoria; Lansdowne, Jennifer L; Schwieger, Karsten; Bouré, Ludovic

    2011-11-01

    The transfixation pin cast (TPC) is an external skeletal fixation technique used to treat horses with distal limb fractures, but its use is often associated with pin-loosening and an increased risk of treatment failure. To address implant loosening, the pin sleeve cast system (PSC) was recently designed and consists of a pin-sleeve unit inserted into the bone. Each pin runs through a sleeve placed in the bone, making contact at two fixed points only within the sleeve. Each pin is attached to a ring embedded in a resin cast. In this report, the mechanical performance of a traditional TPC pin arrangement was compared with that of the PSC using validated finite element models of bone substitutes previously tested in vitro. The PSC resulted in a marked reduction in peak strain magnitude around the pins and a more even distribution of strain across the bone cortex. The two systems resulted in comparable proximal fragment displacement and had a similar stress concentration around bone defects during implant removal. The findings suggest that the PSC load transfer mechanism is effective even in geometrically complex structures like equine bones.

  1. External Fixator for Maintaining Reduction Before Volar Plating: A Simple Treatment Method for Association of Osteosynthesis Type C3 Distal Radius Fracture.

    PubMed

    Tsai, Chun-Hao; Hsu, Chin-Jung; Wang, Ta-I; Fong, Yi-Chin; Hsu, Horng-Chaung; Lin, Tsung-Li

    2016-03-01

    Volar plating for Association of Osteosynthesis type C3 distal radius fractures involves more time and more radiation exposure because it is extremely difficult to simultaneously maintain the reduction and restore the congruity of the articular surface. The authors present a technique of maintaining the acceptable reduction by using an external fixator followed by open volar plating for restoring articular congruity. A consecutive series of 96 Association of Osteosynthesis type C3 distal radius fractures treated with the technique were retrospectively reviewed between January 2004 and December 2012. The technique makes surgery simpler and more effective, and reduces radiation exposure.

  2. Success Rate and Complications of Comminuted Intra-Articular Distal Radius Fracture Treatment via Closed Reduction and Use of a Mini-External Fixator

    PubMed Central

    Karimi Nasab, Mohammad Hossein; Shayesteh Azar, Masoud; Fazel Moghaddam, Samira; Taghipour, Mehrdad

    2015-01-01

    Background: Intra-articular fracture of the distal radius is extremely common; however, the management of this fracture is controversial. Objectives: With regard to the importance of intra-articular fracture of the distal radius and the best treatment method for the fracture, we sought to assess the success rate following the treatment of comminuted intra-articular fractures of the distal radius via closed reduction and use of a mini-external fixator. Patients and Methods: This longitudinal retrospective study was undertaken at our department of orthopedics via assessment of radiographs and patient files of those referred from 2006 to 2013. Radiographic criteria included the degree of angulation and shortening of the radius. Data were analyzed using SPSS 18 software and were presented as mean ± standard deviation (SD). The significance level was set at P ≤ 0.05. Results: Overall, ≥ 2 mm shortening of the radius was seen in 28% of the patients, 53% had 2 - 5 mm radial shortening and 19% of the patients had more than 5 mm shortening of the radius. Most of the participants had acceptable outcomes. The mean angulation was 6.28 ± 2.85 degrees and the mean shortening was 3.92 ± 2.22. Thirty-nine percent of the patients had an angulation of less than 5 mm, 56% and 5% had an angulation of 5 - 10 mm and more than 10 mm, respectively. Conclusions: The results of our study showed that the mini-external fixator is a good and effective treatment option for obtaining radial length, angulation and bony union in intra-articular fractures of the distal radius. PMID:26839853

  3. Treatment of unstable distal radius fractures: non-invasive dynamic external fixator versus volar locking plate – functional and radiological outcome in a prospective case-controlled series

    PubMed Central

    Bajwa, Ali S.; Rammappa, Manju; Lee, Ling; Nanda, Rajesh

    2015-01-01

    Introduction: Distal radius fracture (DRF) is a common injury and various treatment modalities including open reduction and internal fixation (ORIF) with volar locking plate are available. More recently, a non-invasive external fixator has been used. Aims: To prospectively compare the use of a non-invasive external fixator with early dynamisation for DRF against ORIF with volar locking plate control group. Methods: Consecutive patients with closed DRF were included in a prospective case-controlled study. Patients were assigned to non-invasive external fixator or ORIF. Minimum follow-up was two years. Follow-up was at weeks 2, 4, 6, 8, 12, 26 and at one and two-year post-operatively. The outcome measures included demographic details, injury mechanism, AO fracture type, risk factors, body mass index (BMI), ulnar styloid fracture and dorsal comminution, radiographs, grip strength and DASH score. Results: Consecutive 50 patients were treated either with non-invasive external fixator (25/50) or with ORIF (25/50) and the mean age of the two groups was 53 years (SD 17.1) and 49 years (SD 19.5), respectively. Demographics were matched in two groups. In the non-invasive external fixator group, there were 10 AO Type-A, 5 Type-B and 10 Type-C fractures. The ORIF group included 8 Type-A, 6 Type-B and 11 Type-C fractures. The mean DASH score at three-months and one-year post-injury in non-invasive fixator group was 12.2 (SD 3.1) and 3.5 (SD 0.7), respectively, significantly greater than those of ORIF group 14.5 (SD 5.6) and 11.2 (SD 4.4), respectively (p < 0.05). Conclusion: DRF treated with non-invasive external fixator can give functional results superior to ORIF at three-months and the trend is maintained at one and two-year post-operatively. PMID:27163089

  4. Comparison of outcome of tibial plafond fractures managed by hybrid external fixation versus two-stage management with final plate fixation

    PubMed Central

    Cisneros, Luis Natera; Gómez, Mireia; Alvarez, Carlos; Millán, Angélica; De Caso, Julio; Soria, Laura

    2016-01-01

    Background: Tibial platfond fractures are usually associated with massive swelling of the foot and ankle, as well as with open wounds. This swelling may cause significant decrease of the blood flow, so the state of the soft tissue is determinant for the surgical indication and the type of implant. This retrospective study compares the union times in cases of tibial plafond fractures managed with a hybrid external fixation as a definitive procedure versus those managed with a two stage strategy with final plate fixation. Materials and Methods: A retrospective study in a polytrauma referral hospital was performed between 2005 and 2011. Patients with a tibial plafond fracture, managed with a hybrid external fixation as a definitive procedure or managed with a two stage strategy with the final plate fixation were included in the study. Postoperative radiographs were evaluated by two senior surgeons. Fracture healing was defined as callus bridging of one cortex, seen on both lateral and anteroposterior X-ray. The clinical outcome was evaluated by means of 11 points Numerical Rating Scale for pain and The American Orthopedic Foot and Ankle Society ankle score, assessed at the last followup visit. Thirteen patients had been managed with a hybrid external fixation and 18 with a two-stage strategy with the final plate fixation. There were 14 males and 17 females with a mean age of 48 years (range 19–82 years). The mean followup was 24 months (range 24–70 months). Results: The mean time from surgery to weight bearing was 7 ± 6.36 days for the hybrid fixation group and 57.43 ± 15.46 days for the plate fixation group (P < 0.0001); and the mean time from fracture to radiological union was 133.82 ± 37.83) and 152.8 ± 72.33 days respectively (P = 0.560). Conclusion: Besides the differences between groups regarding the baseline characteristics of patients, the results of this study suggest that in cases of tibial plafond fractures, the management with a hybrid external

  5. Management of humeral and femoral fractures in dogs and cats with linear- circular hybrid external skeletal fixators.

    PubMed

    Kirkby, Kristin A; Lewis, Daniel D; Lafuente, M Pilar; Radasch, Robert M; Fitzpatrick, Noel; Farese, James P; Wheeler, Jason L; Hernandez, Jorge A

    2008-01-01

    Linear-circular hybrid fixators were used to stabilize humeral and femoral fractures in 21 dogs and five cats. Twenty-two of 24 fractures with sufficient follow-up radiographic evaluation obtained union. Time to radiographic union ranged from 25 to 280 days (mean +/- standard deviation [SD] 110+/-69 days; median 98 days). Eleven animals developed minor and two dogs developed major pin and/or wire tract inflammation. Functional outcome was rated as excellent (n=16), good (n=5), and fair (n=3) at the time of final long-term assessment (range 4.5 to 60.0 months; mean +/- SD 28.4+/-15.4 months; median 28.5 months). Follow-up information was unavailable for two animals. Hybrid fixators were useful constructs for stabilization of humeral and femoral fractures, particularly fractures with short, juxta-articular fracture segments.

  6. Control of motion of tibial fractures with use of a functional brace or an external fixator. A study of cadavera with use of a magnetic motion sensor.

    PubMed

    McKellop, H; Hoffmann, R; Sarmiento, A; Ebramzadeh, E

    1993-07-01

    A computer-linked magnetic motion transducer was used to monitor and record the six components of motion of the bone fragments in eight cadaveric tibiae in which a simulated, oblique fracture of the middle of the shaft had been stabilized with a functional brace. The limbs were mounted in a servo-hydraulic testing frame, and a cyclic load of 150 newtons was applied along the axis of the tibia. Motion sensors, attached to each side of the fracture, measured and displayed the values of the three translations (axial, anterior-posterior, and medial-lateral), the axial rotation, and the two angulations (anterior-posterior and varus-valgus) as they occurred. Although only an axial load was applied, the off-axis motions were comparable in magnitude with the motion along the axis. The elastic (recoverable) translations of the fragments ranged from 0.5 to 1.9 millimeters, about four to ten times larger than the corresponding motions that were recorded in an earlier study of such fractures that had been stabilized with two types of external fixators. The recoverable rotation and angulations of the fragments of the limbs in the functional brace ranged from 0.7 to 1.2 degrees, about ten times those recorded when the external fixators were used.

  7. Early results of a simple distraction dynamic external fixator in management of comminuted intra-articular fractures of base of middle phalanx.

    PubMed

    Mansha, Muhammad; Miranda, Sanjay

    2013-12-01

    Treatment for comminuted fracture dislocations of the proximal interphalangeal joint (pilon injuries) remains a challenge. We present our short term results of twelve pilon fracture dislocations treated by closed reduction and application of a distraction dynamic external fixator. The aim of the study was to assess the clinical outcomes and compare them to the original description by Hynes and Giddins. A cohort of 12 consecutive patients with pilon fracture of the proximal interphalangeal joint (comminuted fracture of the base of middle phalanx, longitudinally unstable with joint subluxation), were treated with this method over the study period. Data was collected by an independent observer at last follow-up appointment in the clinic. The outcome measures recorded were; level of residual pain, arc of motion, X-ray appearance, return to work and satisfaction with the procedure. The study group comprises of 7 male and 5 female patients at a mean age of 38.1 years (range 21-70 years). The average range of movement achieved was 13-87° at a mean follow-up of 16.4 weeks (Range 12-42 weeks). Early return to work, good pain relief and high level of patient satisfaction were achieved. No serious complication was noted during this period. We used the construct with slight modification of the original description and we feel this modification may help to reduce the pin site infection. We found the results reproducible and based on our experience we recommend this technique to treat these complex intra-articular fractures of base of middle phalanx.

  8. Assessment of the Potential Impacts of Hydraulic Fracturing for Oil and Gas on Drinking Water Resources (External Review Draft)

    EPA Science Inventory

    This assessment provides a review and synthesis of available scientific literature and data to assess the potential for hydraulic fracturing for oil and gas to impact the quality or quantity of drinking water resources, and identifies factors affecting the frequency or severity o...

  9. Outcomes of anterolateral thigh-free flaps and conversion from external to internal fixation with bone grafting in gustilo type IIIB open tibial fractures.

    PubMed

    Lee, Jae Hoon; Chung, Duke Whan; Han, Chung Soo

    2012-09-01

    The purpose of this study was to analyze the utility and the clinical outcomes of anterolateral thigh (ALT)-free flaps and conversion from external to internal fixation with plating and bone grafting in Gustilo type IIIB open tibial fractures. A total of 21 patients were analyzed retrospectively. The mean follow-up period was 18 months and the mean age was 46.7 years. There were 18 men and three women. The mean time from injury to flap coverage was 11.6 days. The mean size of flaps used was 15.3 × 8.2 cm. The mean size of bone defects was 2.26 cm. Segmental bone defects were observed in 5 five cases, for which bone transport or vascularized fibular graft were performed. When flaps were successful and the fracture sites did not have any evidence of infection, internal fixation with plates and bone grafting were performed. Flaps survived in 20 cases. In the 20 cases with successful flaps, two cases developed osteomyelitis, but the 20 cases achieved solid bone union at a mean of 8.6 months after the injury, salvaging the lower extremity in 100% of the cases. At the last follow-up, 9 nine cases were measured excellent or good; 6, fair; and 6, poor in the functional assessment based on the method developed by Puno et al. ALT- free flaps to cover soft tissue defects in Gustilo type IIIB open tibial fractures are considered as useful option for the treatment of composite defects. In addition, conversion to internal fixation and bone grafting can be an alternative method in order to reduce the risk of complications and inconvenience of external fixators.

  10. Treatment of reducible unstable fractures of the distal radius in adults: a randomised controlled trial of De Palma percutaneous pinning versus bridging external fixation

    PubMed Central

    2010-01-01

    Background At present, there is no conclusive evidence regarding the best treatment method for reducible unstable fractures of the distal radius. This study compared the effectiveness of two methods used in surgical treatment of such fractures: percutaneous pinning and external fixation. Methods We randomly allocated 100 patients into two groups treated surgically with modified De Palma percutaneous pinning and bridging external fixation. Independent but not blinded evaluators administered the DASH quality-of-life questionnaire at postoperative months 6 and 24, performed functional assessment of pain, range of motion, and palm grip strength, and radiographic examinations (volar and radial angle, and height of the radius) before the operation, immediately afterwards, and at 6 and 24 months postoperative. Modified De Palma percutaneous pinning patients used an above-elbow cast whereas external fixation group had unrestricted elbow motion after surgery. Patients who for any reason demonstrated treatment failure or required additional interventions were followed up and their results were included in the group into which these patients had initially been randomised according to the intention-to-treat principle. A significance level of 5% (alpha = 0.05). was used for all statistical tests, such that tests presenting a p-value less than 0.05 were considered statistically significant. Results Ninety one (58.8 mean age and 66 participants were female) were included in the final assessment at 24 months. The DASH questionnaire evaluation showed a statistically significant result favouring the De Palma group (mean difference = -7.1 p = 0.044) after six months, but this was not maintained at 24 months. There were no statistically differences between the groups with respect to palm grip strength. Analysis of the range-of-motion limitation index (uninjured side minus affected side motion of) showed a statistical difference (mean difference = 2.4 p = 0.043) favoring the external

  11. Diagnostic accuracy of the gravity stress test and clinical signs in cases of isolated supination-external rotation-type lateral malleolar fractures.

    PubMed

    Nortunen, S; Flinkkilä, T; Lantto, I; Kortekangas, T; Niinimäki, J; Ohtonen, P; Pakarinen, H

    2015-08-01

    We prospectively assessed the diagnostic accuracy of the gravity stress test and clinical findings to evaluate the stability of the ankle mortise in patients with supination-external rotation-type fractures of the lateral malleolus without widening of the medial clear space. The cohort included 79 patients with a mean age of 44 years (16 to 82). Two surgeons assessed medial tenderness, swelling and ecchymosis and performed the external rotation (ER) stress test (a reference standard). A diagnostic radiographer performed the gravity stress test. For the gravity stress test, the positive likelihood ratio (LR) was 5.80 with a 95% confidence interval (CI) of 2.75 to 12.27, and the negative LR was 0.15 (95% CI 0.07 to 0.35), suggesting a moderate change from the pre-test probability. Medial tenderness, both alone and in combination with swelling and/or ecchymosis, indicated a small change (positive LR, 2.74 to 3.25; negative LR, 0.38 to 0.47), whereas swelling and ecchymosis indicated only minimal changes (positive LR, 1.41 to 1.65; negative LR, 0.38 to 0.47). In conclusion, when gravity stress test results are in agreement with clinical findings, the result is likely to predict stability of the ankle mortise with an accuracy equivalent to ER stress test results. When clinical examination suggests a medial-side injury, however, the gravity stress test may give a false negative result.

  12. Treatment of reducible unstable fractures of the distal radius: randomized clinical study comparing the locked volar plate and external fixator methods: study protocol

    PubMed Central

    2014-01-01

    Background Various treatments are available for reducible unstable fractures of the distal radius, such as closed reduction combined with fixation by external fixator (EF), and rigid internal fixation using a locked volar plate (VP). Although there are studies comparing these methods, there is no conclusive evidence indicating which treatment is best. The hypothesis of this study is that surgical treatment with a VP is more effective than EF from the standpoint of functional outcome (patient-reported). Methods/Design The study is randomized clinical trial with parallel groups and a blinded evaluator and involves the surgical interventions EF and VP. Patients will be randomly assigned (assignment ratio 1:1) using sealed opaque envelopes. This trial will include consecutive adult patients with an acute (up to 15 days) displaced, unstable fracture of the distal end of the radius of type A2, A3, C1, C2 or C3 by the Arbeitsgemeinschaft für Osteosynthesefragen–Association for the Study of Internal Fixation classification and type II or type III by the IDEAL32 classification, without previous surgical treatments of the wrist. The surgical intervention assigned will be performed by three surgical specialists familiar with the techniques described. Evaluations will be performed at 2, and 8 weeks, 3, 6 and 12 months, with the primary outcomes being measured by the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire and measurement of pain (Visual Analog Pain Scale and digital algometer). Secondary outcomes will include radiographic parameters, objective functional evaluation (goniometry and dynamometry), and the rate of complications and method failure according to the intention-to-treat principle. Final postoperative evaluations (6 and 12 months) will be performed by independent blinded evaluators. For the Student’s t-test, a difference of 10 points in the DASH score, with a 95% confidence interval, a statistical power of 80%, and 20% sampling error

  13. External Fixation combined with Limited Internal Fixation versus Open Reduction Internal Fixation for Treating Ruedi-Allgower Type III Pilon Fractures

    PubMed Central

    Guo, Yongzhi; Tong, Liangyong; Li, Shaoguang; Liu, Zhi

    2015-01-01

    Background The optimal treatment of type III pilon fractures remains controversial. Hence, we performed this study to investigate whether open reduction and internal fixation (ORIF) is superior to external fixations combined with limited internal fixations (EFLIF). Material/Methods From January 2012 to October 2013, a total of 78 patients were included. Twenty-six patients underwent EFLIF and 52 patients underwent ORIF. All subjects were followed up at 1, 3, 6, and 12 months postoperatively. All outcomes and complications were recorded. Results No statistical differences were observed in Mazur score or ROM between the 2 groups. There were significant differences between the 2 groups in hospital stay (P<0.001), reduction results (P=0.019), screw loosening (P=0.025), and traumatic arthritis (P=0.037). Conclusions Similar functional outcomes were achieved in EFLIF and ORIF groups. Due to several limitations of this study, a well-designed randomized controlled trial involving more patients and long-term follow-up is needed to find an optimal treatment protocol. PMID:26050786

  14. Accuracy in the diagnosis of vertical root fractures, external root resorptions, and root perforations using cone-beam computed tomography with different voxel sizes of acquisition

    PubMed Central

    Bragatto, Fernanda Paula; Iwaki Filho, Liogi; Kasuya, Amanda Vessoni Barbosa; Chicarelli, Mariliani; Queiroz, Alfredo Franco; Takeshita, Wilton Mitsunari; Iwaki, Lilian Cristina Vessoni

    2016-01-01

    Aim: The aim of this study is to assess the accuracy of images acquired with cone-beam computed tomography (CBCT) in the identification of three different root alterations. Materials and Methods: Forty human premolars were allocated to four experimental groups (n = 10): sound teeth (control), vertical root fracture (VRF), external root resorption (ERR), and root perforation (RP). After the root alterations had been produced, four teeth were randomly assembled into 10 macerated mandibles and submitted to CBCT. Images were acquired with five voxel sizes (0.125, 0.200, 0.250, 0.300, and 0.400 mm) and assessed by three experienced dental radiologists. Sensitivity, specificity, positive and negative predictive values, and the areas under the receiver operating characteristic curve (accuracy) were calculated. The accuracy of imaging in different voxel sizes was compared with Tukey exact binomial test (α=5%). Results: Accuracy with voxel sizes 0.125, 0.200, and 0.250 mm was significantly higher in the detection of ERRs and VRFs than voxel sizes 0.300 and 0.400 mm. No statistical difference was found in terms of accuracy among any of the studied voxel sizes in the identification of RPs. Conclusions: Voxel size 0.125 mm produced images with the best resolution without increasing radiation levels to the patient when compared to voxel sizes 0.200 and 0.250 mm. Voxel sizes 0.300 and 0.400 mm should be avoided in the identification of root alterations. PMID:27994322

  15. Bone Fractures Following External Beam Radiotherapy and Limb-Preservation Surgery for Lower Extremity Soft Tissue Sarcoma: Relationship to Irradiated Bone Length, Volume, Tumor Location and Dose

    SciTech Connect

    Dickie, Colleen I.; Parent, Amy L.; Griffin, Anthony M.; Fung, Sharon; Chung, Peter W.M.; Catton, Charles N.; Ferguson, Peter C.; Wunder, Jay S.; Bell, Robert S.; Sharpe, Michael B.; O'Sullivan, Brian

    2009-11-15

    Purpose: To examine the relationship between tumor location, bone dose, and irradiated bone length on the development of radiation-induced fractures for lower extremity soft tissue sarcoma (LE-STS) patients treated with limb-sparing surgery and radiotherapy (RT). Methods and Materials: Of 691 LE-STS patients treated from 1989 to 2005, 31 patients developed radiation-induced fractures. Analysis was limited to 21 fracture patients (24 fractures) who were matched based on tumor size and location, age, beam arrangement, and mean total cumulative RT dose to a random sample of 53 nonfracture patients and compared for fracture risk factors. Mean dose to bone, RT field size (FS), maximum dose to a 2-cc volume of bone, and volume of bone irradiated to >=40 Gy (V40) were compared. Fracture site dose was determined by comparing radiographic images and surgical reports to fracture location on the dose distribution. Results: For fracture patients, mean dose to bone was 45 +- 8 Gy (mean dose at fracture site 59 +- 7 Gy), mean FS was 37 +- 8 cm, maximum dose was 64 +- 7 Gy, and V40 was 76 +- 17%, compared with 37 +- 11 Gy, 32 +- 9 cm, 59 +- 8 Gy, and 64 +- 22% for nonfracture patients. Differences in mean, maximum dose, and V40 were statistically significant (p = 0.01, p = 0.02, p = 0.01). Leg fractures were more common above the knee joint. Conclusions: The risk of radiation-induced fracture appears to be reduced if V40 <64%. Fracture incidence was lower when the mean dose to bone was <37 Gy or maximum dose anywhere along the length of bone was <59 Gy. There was a trend toward lower mean FS for nonfracture patients.

  16. Origin of compression-induced failure in brittle solids under shock loading

    NASA Astrophysics Data System (ADS)

    Huang, J. Y.; Li, Y.; Liu, Q. C.; Zhou, X. M.; Liu, L. W.; Liu, C. L.; Zhu, M. H.; Luo, S. N.

    2015-10-01

    The origin of compression-induced failure in brittle solids has been a subject of debate. Using in situ, high-speed, strain field mapping of a representative material, polymethylmethacrylate, we reveal that shock loading leads to heterogeneity in a compressive strain field, which in turn gives rise to localized lateral tension and shear through Poisson's effects, and, subsequently, localized microdamage. A failure wave nucleates from the impact surface and its propagation into the microdamage zone is self-sustained, triggering interior failure. Its velocity increases with increasing shock strength and eventually approaches the shock velocity. The seemingly puzzling phenomena observed in previous experiments, including incubation time, failure wave velocity variations, and surface roughness effects, can all be explained consistently with the nucleation and growth of the microdamage, and the effects of loading strength and preexisting defects.

  17. Nose fracture

    MedlinePlus

    Fracture of the nose; Broken nose; Nasal fracture; Nasal bone fracture; Nasal septal fracture ... A fractured nose is the most common fracture of the face. It ... with other fractures of the face. Sometimes a blunt injury can ...

  18. Triplane fractures in the hand.

    PubMed

    Garcia Mata, S; Hidalgo Ovejero, A; Martinez Grande, M

    1999-02-01

    Two new cases of triplane fracture of the distal tibia are reported in the proximal phalanx of the thumb and the distal radius, respectively, of a 12-year-old girl and a 13-year-old boy. Neither fracture showed any displacement, achieving healing at 4 weeks of external immobilization. Triplane fractures can occur across growth plates other than the distal tibia. Because of the rapid physiologic physeal arrest, the potential for growth deformity is null. In cases without displacement, these fractures should be treated conservatively by external immobilization, as one would treat a one-plane fracture.

  19. Paratrooper's Ankle Fracture: Posterior Malleolar Fracture

    PubMed Central

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

    2015-01-01

    Background We assessed the frequency and types of ankle fractures that frequently occur during parachute landings of special operation unit personnel and analyzed the causes. Methods 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. Results 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. Conclusions Posterior malleolar fractures occurred in 41.07% of ankle fractures sustained in parachute landings. Because most of the ankle fractures in parachute injuries were

  20. Transcriptome-wide analysis of compression-induced microRNA expression alteration in breast cancer for mining therapeutic targets.

    PubMed

    Kim, Baek Gil; Kang, Suki; Han, Hyun Ho; Lee, Joo Hyun; Kim, Ji Eun; Lee, Sung Hwan; Cho, Nam Hoon

    2016-05-10

    Tumor growth-generated mechanical compression may increase or decrease expression of microRNAs, leading to tumor progression. However, little is known about whether mechanical compression induces aberrant expression of microRNAs in cancer and stromal cells. To investigate the relationship between compression and microRNA expression, microRNA array analysis was performed with breast cancer cell lines and cancer-associated fibroblasts (CAFs) exposed to different compressive conditions. In our study, mechanical compression induced alteration of microRNA expression level in breast cancer cells and CAFs. The alteration was greater in the breast cancer cells than CAFs. Mechanical compression mainly induced upregulation of microRNAs rather than downregulation. In a parallel mRNA array analysis, more than 25% of downregulated target genes were functionally involved in tumor suppression (apoptosis, cell adhesion, and cell cycle arrest), whereas generally less than 15% were associated with tumor progression (epithelial-mesenchymal transition, migration, invasion, and angiogenesis). Of all cells examined, MDA-MB-231 cells showed the largest number of compression-upregulated microRNAs. miR-4769-5p and miR-4446-3p were upregulated by compression in both MDA-MB-231 cells and CAFs. Our results suggest that mechanical compression induces changes in microRNA expression level, which contribute to tumor progression. In addition, miR-4769-5p and miR-4446-3p may be potential therapeutic targets for incurable cancers, such as triple negative breast cancer, in that this would reduce or prevent downregulation of tumor-suppressing genes in both the tumor and its microenvironment simultaneously.

  1. Transcriptome-wide analysis of compression-induced microRNA expression alteration in breast cancer for mining therapeutic targets

    PubMed Central

    Kim, Baek Gil; Kang, Suki; Han, Hyun Ho; Lee, Joo Hyun; Kim, Ji Eun; Lee, Sung Hwan; Cho, Nam Hoon

    2016-01-01

    Tumor growth–generated mechanical compression may increase or decrease expression of microRNAs, leading to tumor progression. However, little is known about whether mechanical compression induces aberrant expression of microRNAs in cancer and stromal cells. To investigate the relationship between compression and microRNA expression, microRNA array analysis was performed with breast cancer cell lines and cancer-associated fibroblasts (CAFs) exposed to different compressive conditions. In our study, mechanical compression induced alteration of microRNA expression level in breast cancer cells and CAFs. The alteration was greater in the breast cancer cells than CAFs. Mechanical compression mainly induced upregulation of microRNAs rather than downregulation. In a parallel mRNA array analysis, more than 25% of downregulated target genes were functionally involved in tumor suppression (apoptosis, cell adhesion, and cell cycle arrest), whereas generally less than 15% were associated with tumor progression (epithelial-mesenchymal transition, migration, invasion, and angiogenesis). Of all cells examined, MDA-MB-231 cells showed the largest number of compression-upregulated microRNAs. miR-4769-5p and miR-4446-3p were upregulated by compression in both MDA-MB-231 cells and CAFs. Our results suggest that mechanical compression induces changes in microRNA expression level, which contribute to tumor progression. In addition, miR-4769-5p and miR-4446-3p may be potential therapeutic targets for incurable cancers, such as triple negative breast cancer, in that this would reduce or prevent downregulation of tumor-suppressing genes in both the tumor and its microenvironment simultaneously. PMID:27027350

  2. Fractures in anisotropic media

    NASA Astrophysics Data System (ADS)

    Shao, Siyi

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

  3. Notochordal cell disappearance and modes of apoptotic cell death in a rat tail static compression-induced disc degeneration model

    PubMed Central

    2014-01-01

    Introduction The intervertebral disc has a complex structure originating developmentally from both the mesenchyme and notochord. Notochordal cells disappear during adolescence, which is also when human discs begin to show degenerative signs. During degeneration later in life, disc cells decline because of apoptosis. Although many animal models have been developed to simulate human disc degeneration, few studies have explored the long-term changes in cell population and phenotype. Our objective was to elucidate the time-dependent notochordal cell disappearance and apoptotic cell death in a rat tail static compression-induced disc degeneration model. Methods Twenty-four 12-week-old male Sprague–Dawley rat tails were instrumented with an Ilizarov-type device and loaded statically at 1.3 MPa for up to 56 days. Loaded and distal-unloaded discs were harvested. Changes in cell number and phenotype were assessed with histomorphology and immunofluorescence. Apoptosis involvement was determined with terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining and immunohistochemistry. Results The number of disc nucleus pulposus and annulus fibrosus cells decreased with the loading period; particularly, the decrease was notable at day 7 in larger, vacuolated, cytokeratin-8- and galectin-3-co-positive cells, indicating notochordal origin. Subsequently, the proportion of cells positive for TUNEL and cleaved caspase-3, markers of apoptosis induction, increased from day 7 through day 56. Although the percentage of cells immunopositive for cleaved caspase-8, a marker of apoptosis initiation through the death-receptor pathway, increased only at day 7, the percentage of cells immunopositive for cleaved caspase-9 and p53-regulated apoptosis-inducing protein 1 (p53AIP1), markers of apoptosis initiation through the p53-mediated mitochondrial pathway, increased from day 7 through day 56. The percentage of cells immunopositive for B-cell lymphoma 2 (Bcl-2) and silent

  4. Shoulder Fractures

    MedlinePlus

    ... Journal of Hand Surgery (JHS) Home Anatomy Shoulder Fractures Email to a friend * required fields From * To * ... create difficulty with its function. Types of Shoulder Fractures The type of fracture varies by age. Most ...

  5. Stress Fractures

    MedlinePlus

    Stress fractures Overview By Mayo Clinic Staff Stress fractures are tiny cracks in a bone. They're caused by ... up and down or running long distances. Stress fractures can also arise from normal use of a ...

  6. Greenstick Fractures

    MedlinePlus

    Greenstick fractures Overview By Mayo Clinic Staff A greenstick fracture occurs when a bone bends and cracks, instead of breaking completely into separate pieces. The fracture looks similar to what happens when you try ...

  7. Compression induced phase transition of nematic brush: A mean-field theory study

    SciTech Connect

    Tang, Jiuzhou; Zhang, Xinghua; Yan, Dadong

    2015-11-28

    Responsive behavior of polymer brush to the external compression is one of the most important characters for its application. For the flexible polymer brush, in the case of low grafting density, which is widely studied by the Gaussian chain model based theory, the compression leads to a uniform deformation of the chain. However, in the case of high grafting density, the brush becomes anisotropic and the nematic phase will be formed. The normal compression tends to destroy the nematic order, which leads to a complex responsive behaviors. Under weak compression, chains in the nematic brush are buckled, and the bending energy and Onsager interaction give rise to the elasticity. Under deep compression, the responsive behaviors of the nematic polymer brush depend on the chain rigidity. For the compressed rigid polymer brush, the chains incline to re-orientate randomly to maximize the orientational entropy and its nematic order is destroyed. For the compressed flexible polymer brush, the chains incline to fold back to keep the nematic order. A buckling-folding transition takes place during the compressing process. For the compressed semiflexible brush, the chains are collectively tilted to a certain direction, which leads to the breaking of the rotational symmetry in the lateral plane. These responsive behaviors of nematic brush relate to the properties of highly frustrated worm-like chain, which is hard to be studied by the traditional self-consistent field theory due to the difficulty to solve the modified diffusion equation. To overcome this difficulty, a single chain in mean-field theory incorporating Monte Carlo simulation and mean-field theory for the worm-like chain model is developed in present work. This method shows high performance for entire region of chain rigidity in the confined condition.

  8. Compression induced phase transition of nematic brush: A mean-field theory study

    NASA Astrophysics Data System (ADS)

    Tang, Jiuzhou; Zhang, Xinghua; Yan, Dadong

    2015-11-01

    Responsive behavior of polymer brush to the external compression is one of the most important characters for its application. For the flexible polymer brush, in the case of low grafting density, which is widely studied by the Gaussian chain model based theory, the compression leads to a uniform deformation of the chain. However, in the case of high grafting density, the brush becomes anisotropic and the nematic phase will be formed. The normal compression tends to destroy the nematic order, which leads to a complex responsive behaviors. Under weak compression, chains in the nematic brush are buckled, and the bending energy and Onsager interaction give rise to the elasticity. Under deep compression, the responsive behaviors of the nematic polymer brush depend on the chain rigidity. For the compressed rigid polymer brush, the chains incline to re-orientate randomly to maximize the orientational entropy and its nematic order is destroyed. For the compressed flexible polymer brush, the chains incline to fold back to keep the nematic order. A buckling-folding transition takes place during the compressing process. For the compressed semiflexible brush, the chains are collectively tilted to a certain direction, which leads to the breaking of the rotational symmetry in the lateral plane. These responsive behaviors of nematic brush relate to the properties of highly frustrated worm-like chain, which is hard to be studied by the traditional self-consistent field theory due to the difficulty to solve the modified diffusion equation. To overcome this difficulty, a single chain in mean-field theory incorporating Monte Carlo simulation and mean-field theory for the worm-like chain model is developed in present work. This method shows high performance for entire region of chain rigidity in the confined condition.

  9. Stabilization and treatment of Colles' fractures in elderly patients.

    PubMed

    Blakeney, William G

    2010-11-18

    Colles' fractures (fractures of the distal radius) are extremely common in the elderly. These fractures tend to result in displacement in elderly people because they have osteoporotic bone. Fracture displacement in the elderly, however, does not necessarily result in functional impairment. This review looks at the current literature on distal radius fractures in the elderly and the treatment options for stabilization of these fractures. These include conservative management with cast immobilization or surgical options: internal fixation, external fixation, percutaneous pinning, and bone substitutes.

  10. Staged treatment of pilon fractures

    PubMed Central

    Deivaraju, Chenthuran; Vlasak, Richard; Sadasivan, Kalia

    2015-01-01

    Aim To evaluate outcomes following staged anterolateral plating of pilon fractures. Methods Over a 5 year period, patients with pilon fractures received four treatment regimens (staged anterolateral plating, staged medial plating, definitive external fixation, early total care). We defined five outcomes (reduction, soft tissue complications, infection, non-union, malunion) and assessed the outcome of fractures treated by these interventions. Results Staged anterolateral plating or staged medial plating achieved comparable reduction and soft tissue complications. Staged medial plating had higher infection rates, malunion and non-union rates. Conclusions Staged anterolateral plating is superior to staged medial plating in the management of pilon fractures. PMID:26719618

  11. Quantitative characterization of the interfacial adhesion of Ni thin film on steel substrate: A compression-induced buckling delamination test

    NASA Astrophysics Data System (ADS)

    Zhu, W.; Zhou, Y. C.; Guo, J. W.; Yang, L.; Lu, C.

    2015-01-01

    A compression-induced buckling delamination test is employed to quantitatively characterize the interfacial adhesion of Ni thin film on steel substrate. It is shown that buckles initiate from edge flaws and surface morphologies exhibit symmetric, half-penny shapes. Taking the elastoplasticity of film and substrate into account, a three-dimensional finite element model for an edge flaw with the finite size is established to simulate the evolution of energy release rates and phase angles in the process of interfacial buckling-driven delamination. The results show that delamination propagates along both the straight side and curved front. The mode II delamination plays a dominant role in the process with a straight side whilst the curved front experiences almost the pure mode I. Based on the results of finite element analysis, a numerical model is developed to evaluate the interfacial energy release rate, which is in the range of 250-315 J/m2 with the corresponding phase angle from -41° to -66°. These results are in agreement with the available values determined by other testing methods, which confirms the effectiveness of the numerical model.

  12. Normalization of compression-induced hemodynamics in patients responding to neoadjuvant chemotherapy monitored by dynamic tomographic optical breast imaging (DTOBI)

    PubMed Central

    Sajjadi, Amir Y.; Isakoff, Steven J.; Deng, Bin; Singh, Bhawana; Wanyo, Christy M.; Fang, Qianqian; Specht, Michelle C.; Schapira, Lidia; Moy, Beverly; Bardia, Aditya; Boas, David A.; Carp, Stefan A.

    2017-01-01

    We characterize novel breast cancer imaging biomarkers for monitoring neoadjuvant chemotherapy (NACT) and predicting outcome. Specifically, we recruited 30 patients for a pilot study in which NACT patients were imaged using dynamic tomographic optical breast imaging (DTOBI) to quantify the hemodynamic changes due to partial mammographic compression. DTOBI scans were obtained pre-treatment (referred to as day 0), as well as 7 and 30 days into therapy on female patients undergoing NACT. We present data for the 13 patients who participated in both day 0 and 7 measurements and had evaluable data, of which 7 also returned for day 30 measurements. We acquired optical images over 2 minutes following 4-8 lbs (18-36 N) of compression. The timecourses of tissue-volume averaged total hemoglobin (HbT), as well as hemoglobin oxygen saturation (SO2) in the tumor vs. surrounding tissues were compared. Outcome prediction metrics based on the differential behavior in tumor vs. normal areas for responders (>50% reduction in maximum diameter) vs. non-responders were analyzed for statistical significance. At baseline, all patients exhibit an initial decrease followed by delayed recovery in HbT, and SO2 in the tumor area, in contrast to almost immediate recovery in surrounding tissue. At day 7 and 30, this contrast is maintained in non-responders; however, in responders, the contrast in hemodynamic time-courses between tumor and normal tissue starts decreasing at day 7 and substantially disappears at day 30. At day 30 into NACT, responding tumors demonstrate “normalization” of compression induced hemodynamics vs. surrounding normal tissue whereas non-responding tumors did not. This data suggests that DTOBI imaging biomarkers, which are governed by the interplay between tissue biomechanics and oxygen metabolism, may be suitable for guiding NACT by offering early predictions of treatment outcome. PMID:28270967

  13. [Atlas fractures].

    PubMed

    Schären, S; Jeanneret, B

    1999-05-01

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

  14. Skull fracture

    MedlinePlus

    ... compress the underlying brain tissue (subdural or epidural hematoma). A simple fracture is a break in the bone without damage ... Causes of skull fracture can include: Head trauma Falls, automobile accidents, physical assault, and sports

  15. Rib Fractures

    MedlinePlus

    ... From Brain Injury Additional Content Medical News Rib Fractures By Thomas G. Weiser, MD, MPH, Department of ... Hemothorax Injury to the Aorta Pulmonary Contusion Rib Fractures Tension Pneumothorax Traumatic Pneumothorax (See also Introduction to ...

  16. Hand Fractures

    MedlinePlus

    ... Thumb Arthritis Thumb Sprains Trigger Finger Tumors Wrist Fracture Hand Safety Fireworks Safety Lawnmower Safety Snowblower safety ... Tunnel Ganglion Cysts Thumb Arthritis Trigger Finger Wrist Fracture Hand Safety Fireworks Safety Lawnmower Safety Snowblower safety ...

  17. Facial fractures.

    PubMed Central

    Carr, M. M.; Freiberg, A.; Martin, R. D.

    1994-01-01

    Emergency room physicians frequently see facial fractures that can have serious consequences for patients if mismanaged. This article reviews the signs, symptoms, imaging techniques, and general modes of treatment of common facial fractures. It focuses on fractures of the mandible, zygomaticomaxillary region, orbital floor, and nose. Images p520-a p522-a PMID:8199509

  18. [Bone disease with Pain. Colles' fracture].

    PubMed

    Yajima, Hiroshi

    2008-11-01

    The distal radius is one of the most commonly fractured long bone. Colles' fracture results from a fall on the dorsiflexed and pronated hand. The dinner-fork deformity is the typical deformity of the Colles' fracture. For patients with no or a little displacement, conservative treatment is applied. The non-bridge type external fixator is applied for patients without an intra articular fracture. For patients with a comminuted fracture, the locking plate (volar approach) is recommended. During the healing period, shoulder, elbow and finger exercise should be insisted.

  19. Effects of gadolinium chloride on basal flow and compression-induced rapid hyperemia in the rabbit masseter muscle.

    PubMed

    Turturici, M; Roatta, S

    2014-06-01

    Aim of the present study is to investigate the role of mechano-sensitive channels on basal muscle blood flow and on the compression-induced rapid hyperaemia. To this aim, the mechano-sensitive channel blocker Gadolinium (Gd(3+)) is employed, which already proved to reduce the myogenic response in isolated vessels. Muscle blood flow (MaBF) was recorded from the masseteric artery in 8 urethane-anesthetized rabbits. Rapid hyperemic responses were evoked by 1-s lasting compressions of the masseter muscle (MC) delivered before and after close arterial infusion of Gd(3+) in the masseteric artery. Three infusions were performed at 1-h interval, producing estimated plasma concentration (EPC) of 0.045, 0.45 and 4.5 mM, in the masseteric artery. The amplitude of the hyperaemic response to MC, equal to 195±77% of basal flow in control condition, was reduced by 9.5±19.4% (p=0.18) and 45±28% (p<0.01) while basal MaBf increased by 10±3% (p=0.90) and by 68±30% (p<0.01) at EPC of 0.045 and 0.45 mM, respectively. At EPC of 4.5 mM a strong reduction in both MaBF (by 54±13%, p<0.01) and MC response (75±12%, p<0.01) was instead observed. These effects did not depend on time from infusion. At all doses employed Gd(3+) never affected arterial blood pressure, heart rate and contralateral MaBF. While the effects observed at the highest EPC likely result from blood vessel occlusion due to Gd(3+) precipitation, the effects observed at lower concentrations demonstrate that Gd(3+) affects musculo-vascular function by decreasing both resting vascular tone and responsiveness to mechanical stimuli. The results are compatible with a Gd(3+)-induced blockade of vascular mechano-sensitive channels.

  20. [Femoral shaft fractures in children].

    PubMed

    Dietz, H-G; Schlickewei, W

    2011-05-01

    Femoral shaft fractures in children represent 1.5% of all fractures in childhood. Up to the age of 4 years, conservative treatment in a hip spica or short-term overhead traction is the therapy of choice. Femoral shaft fractures between the age of 5 and 16 years should be treated surgically. In over 90% of these cases elastic stable intramedullary nailing (ESIN) is the premier treatment option. Additional end caps can be used for unstable fractures and in length discrepancy. The external fixator and the locking plate are reserved for fractures with severe soft tissue injuries, vascular problems and some specific situations mentioned later on. By adhering to these standards good results can be achieved with a low complication rate.

  1. [Humeral shaft fractures].

    PubMed

    Schittko, A

    2004-08-01

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

  2. Fractures of Distal Radius: An Overview

    PubMed Central

    Meena, Sanjay; Sharma, Pankaj; Sambharia, Abhishek Kumar; Dawar, Ashok

    2014-01-01

    Fractures of distal radius account for up to 20% of all fractures treated in emergency department. Initial assessment includes a history of mechanism of injury, associated injury and appropriate radiological evaluation. Treatment options include conservative management, internal fixation with pins, bridging and non-bridging external fixation, dorsal or volar plating with/without arthroscopy assistance. However, many questions regarding these fractures remain unanswered and good prospective randomized trials are needed. PMID:25657938

  3. Ankle fracture - aftercare

    MedlinePlus

    Malleolar fracture; Tri-malleolar; Bi-malleolar; Distal tibia fracture; Distal fibula fracture; Malleolus fracture ... Some ankle fractures may require surgery when: The ends of the bone are out of line with each other (displaced). The ...

  4. Statistical Physics of Fracture

    SciTech Connect

    Alava, Mikko; Nukala, Phani K; Zapperi, Stefano

    2006-05-01

    Disorder and long-range interactions are two of the key components that make material failure an interesting playfield for the application of statistical mechanics. The cornerstone in this respect has been lattice models of the fracture in which a network of elastic beams, bonds, or electrical fuses with random failure thresholds are subject to an increasing external load. These models describe on a qualitative level the failure processes of real, brittle, or quasi-brittle materials. This has been particularly important in solving the classical engineering problems of material strength: the size dependence of maximum stress and its sample-to-sample statistical fluctuations. At the same time, lattice models pose many new fundamental questions in statistical physics, such as the relation between fracture and phase transitions. Experimental results point out to the existence of an intriguing crackling noise in the acoustic emission and of self-affine fractals in the crack surface morphology. Recent advances in computer power have enabled considerable progress in the understanding of such models. Among these partly still controversial issues, are the scaling and size-effects in material strength and accumulated damage, the statistics of avalanches or bursts of microfailures, and the morphology of the crack surface. Here we present an overview of the results obtained with lattice models for fracture, highlighting the relations with statistical physics theories and more conventional fracture mechanics approaches.

  5. Fracture Management

    MedlinePlus

    ... to hold the fracture in the correct position. • Fiberglass casting is lighter and stronger and the exterior ... with your physician if this occurs. • When a fiberglass cast is used in conjunction with a GORE- ...

  6. Hip Fracture

    MedlinePlus

    ... make older people more likely to trip and fall — one of the most common causes of hip ... Taking steps to maintain bone density and avoid falls can help prevent hip fracture. Signs and symptoms ...

  7. Lisfranc fractures.

    PubMed

    Wright, Amanda; Gerhart, Ann E

    2009-01-01

    Injuries of the tarsometatarsal, or Lisfranc, joint are rarely seen. Lisfranc fractures and fracture dislocations are among the most frequently misdiagnosed foot injuries in the emergency department. A misdiagnosed injury may have severe consequences including chronic pain and loss of foot biomechanics. Evaluation of a foot injury should include a high level of suspicion of a Lisfranc injury, and a thorough work-up is needed for correct diagnosis.

  8. Colles' fracture.

    PubMed

    Altizer, Linda L

    2008-01-01

    Many people "slip and fall", especially in the icy areas of the winter season. To prevent an injury to the head, most people put their hand out to hit the ground first, so the wrist usually gets injured. The most frequent injury from this type of "intervention" is a fracture to the distal radius and/or ulna, which is frequently called a "Colles' fracture."

  9. Boxer's fracture.

    PubMed

    Altizer, Linda

    2006-01-01

    Boxer's fracture is a common name for a fracture of the distal fifth metacarpal and received its name from one of its most common causes, punching an object with a closed fist. It can occur from a fistfight or from punching a hard object. The injury of a "Boxer's Fracture" earned the name from the way in which the injury occurred, punching an immovable object with a closed fist and no boxing mitt (Figure 1). Naturally, a "Boxer" usually punches his fist into his opponent's face or body. An angry person may perform the same action into a person, or into the wall. The third person may be performing a task and strike something with his fist with forceful action accidentally. In any event, if the closed fist "punches" into an immovable or firm object with force, the most frequent injury sustained would be a fracture of the fifth metacarpal neck. Some caregivers would also call a fourth metacarpal neck fracture a boxer's fracture.

  10. Mini external fixation in the hand.

    PubMed

    Ugwonali, Obinwanne Fidelis C; Jupiter, Jesse B

    2006-09-01

    External fixation is an effective means of addressing several pathologies of the hand. The advantages of its use include the ability to achieve stable fixation, minimize soft tissue trauma at the site of injury, and allow wound care and mobilization of adjacent joints. External fixators can be constructed from material readily available in the operating room or obtained from a commercial source. Sufficient rigidity can be achieved by any of these means. Improper placement, although achieving rigid fixation, may compromise motion and overall function if basic principles of external fixation are not followed or if the anatomy of the hand is not taken into consideration. The objective of this article is to describe the technique of application of mini external fixation, emphasizing the basic principles of external fixation as they relate to the specific anatomy of the hand. In addition to fracture fixation, various other uses are described including distraction lengthening, arthrodesis, treatment of nonunion, and infection.

  11. Treatment of fractures in avian species.

    PubMed

    MacCoy, D M

    1992-01-01

    External fixation, with coaptation or Kirschner-Ehmer splints, is a viable treatment for many fractures in captive and wild birds. Important considerations in selecting a device are the weight and size of the device, location of the fracture relative to joints, and prognosis associated with location of the fracture(s). A variety of materials, not limited to traditional medical materials, may be used in coaptation splinting. Straws, plastic spoons, and rubber balls can serve as effective splints. Type I and II Kirschner splints are typically used in birds, although large birds may require a type III splint on leg fractures. The most useful configuration for wing fractures is the type Ia single bar splint using epoxy or acrylic for the connecting bar. This splint is lightweight, positioned close to the patient, and stable for most fractures. The type II splint is an excellent choice for leg fractures at the level of the tibiotarsus and below. The destructive character of psittacines requires all splints be protected from the beak of the bird. Clavicular-furcular and coracoid fractures in small birds may be effectively managed with coaptation splinting. In birds over 400 g body weight, open reduction is needed for best results. Since fractures of the foramen triosseum are usually not surgically repairable, they can be stabilized with coaptation splints. Although humeral fractures may be managed with coaptation in some circumstances, firm stabilization with a type I Kirschner-Ehmer splint or internal fixation is best. Single bone fracture(s) of the radius or ulna can usually be managed with minimal treatment, brailling, or figure-of-eight wraps. Fractures of both the radius and the ulna require a type I Kirschner-Ehmer splint for internal fixation. Coaptation splinting alone is usually indicated for carpal or carpometacarpal injuries. Femoral fractures in small birds may be managed with coaptation splinting, although fractures in large birds or unstable fractures

  12. Fracture types (1) (image)

    MedlinePlus

    ... fracture which goes at an angle to the axis Comminuted - a fracture of many relatively small fragments Spiral - a fracture which runs around the axis of the bone Compound - a fracture (also called ...

  13. Hydraulic fracturing-1

    SciTech Connect

    Not Available

    1990-01-01

    This book contains papers on hydraulic fracturing. Topics covered include: An overview of recent advances in hydraulic fracturing technology; Containment of massive hydraulic fracture; and Fracturing with a high-strength proppant.

  14. Triplane fracture of the distal radius.

    PubMed

    García-Mata, Serafín; Hidalgo-Ovejero, Angel

    2006-07-01

    A case of triplane fracture of the distal radius is reported in a 13-year-old boy. This exceptional fracture showed displacement, and was healed by closed reduction and 6 weeks of external immobilization. Eighteen months later, the patient showed complete physeal arrest of the distal radius, with radio-ulnar length discrepancy but without any repercussion on wrist mobility. The patient was declared asymptomatic 3 years after the injury. Prompt, physiological physeal arrest reduces the potential of growth deformity. These fractures must be treated conservatively by closed reduction (if displacement exists) and external immobilization, just like a normal one-plane fracture. We may suppose that final radio-ulnar discrepancy could lead to a painful and symptomatic ulno-carpal conflict in adult life. The following characteristics can be associated with this rare fracture: (1) occurrence close to the end of the growth period, as in other types of triplane fractures; (2) evolution towards partial or complete growth arrest of the physis, not requiring treatment and (3) stability of the fracture after closed reduction. In the present case, as in the other reported cases, it may also be added that orthopaedic treatment has been the rule, in contrast with triplane fractures occurring in the distal tibia, in which surgical treatment is indicated.

  15. TNF is required for the induction but not the maintenance of compression-induced BME signals in murine tail vertebrae: limitations of anti-TNF therapy for degenerative disc disease.

    PubMed

    Papuga, M Owen; Kwok, Edmund; You, Zhigang; Rubery, Paul T; Dougherty, Paul E; Pryhuber, Gloria; Beck, Christopher A; Hilton, Matthew J; Awad, Hani A; Schwarz, Edward M

    2011-09-01

    While bone marrow edema (BME) is diagnostic of spondyloarthropathy, its nature remains poorly understood. In contrast, BME in ankylosing spondylitis is caused by tumor necrosis factor (TNF)-induced vascular and cellular changes. To investigate the relationship between chronic compression and TNF signaling in compression-induced BME we utilized a tail vertebrae compression model with WT, TNF-Tg, and TNFR1&2-/- mice to evaluate: (i) healing following release of chronic compression, (ii) induction of BME in the absence of TNFR, and (iii) efficacy of anti-TNF therapy. Compression-induced normalized marrow contrast enhancement (NMCE) in WT was significantly decreased threefold (p < 0.01) within 2 weeks of release, while the NMCE values in TNF-Tg vertebrae remained elevated, but had a significant decrease (p < 0.05) by 6 weeks after the release of compression. TNFR1&2-/- mice were resistant to compression-induced BME. Anti-TNF therapy did not affect NMCE versus placebo. Histological examination revealed that NMCE values significantly correlated with marrow vascularity and cellularity (p < 0.05), which account for 76% of the variability of NMCE. Collectively, these data demonstrate a critical role for TNF in the induction of chronic compression-induced BME, but not in its maintenance. Amelioration of BME is achieved through biomechanical stability, but is not affected by anti-TNF therapy.

  16. Condylar fractures.

    PubMed

    Sawhney, Raja; Brown, Ryan; Ducic, Yadranko

    2013-10-01

    The purpose of this article is to review the basic indications for different treatments of condylar and subcondylar fractures. It also reviews the steps of different surgical approaches to access the surgical area and explains the pros and cons of each procedure.

  17. Biomechanical evaluation of the Pinless external fixator.

    PubMed

    Stene, G M; Frigg, R; Schlegel, U; Swiontkowski, M

    1992-01-01

    In open fractures especially in those with severe soft tissue damage, fracture stabilisation is best achieved by using external fixators. There are some intrinsic complications which occur during classical external pin fixation. To overcome the problem of pin track infection and vascular damage from drilling, the Pinless external fixator was developed. It is based on the idea of a forceps with trocar points, which only penetrate the bone cortex superficially. The function of the device was tested in two mechanical trials and two in vitro tests in which one pinless clamp was put under a controlled load of 50 N, 150 cycles/day and studied over a 5 week period in sheep. The loads and time range of the experiment were chosen to simulate a temporary fracture stabilisation in a patient not bearing weight. The main question to be answered was whether the Pinless external fixator would be able to maintain stable fixation. Furthermore, it was to determine the changes at the trocar-to-bone interface. The clamp was found to maintain 72% of the initially applied clamping force after 5 weeks of in vivo application and it was found to be tight at removal. Some decrease of clamping force was found during the first 20 days and then the force tended to level off. There was no slippage nor did the clamp penetrate the cortex. There were no obvious signs of infection around the trocar-holes and in the bacterial tests no pathological cultures were grown. Histology revealed very localised bone reactions, the indentation caused by the trocar tips being only 1.2 mm deep. The study concludes, as far as could be ascertained from these tests, that it is safe to use pinless external fixation for temporary fracture fixation.

  18. Facial Fractures

    PubMed Central

    White, Lawrence M.; Marotta, Thomas R.; McLennan, Michael K.; Kassel, Edward E.

    1992-01-01

    Appropriate clinical radiographic investigation, together with an understanding of the normal radiographic anatomy of the facial skeleton, allows for precise delineation of facial fracutres and associated soft tissue injuries encountered in clinical practice. A combination of multiple plain radiographic views and coronal and axial computed tomographic images allow for optimal delineation of fracture patterns. This information is beneficial in the clinical and surgical management patients with facial injuries

  19. Are Carotid Stent Fractures Clinically Significant?

    SciTech Connect

    Garcia-Toca, Manuel; Rodriguez, Heron E.; Naughton, Peter A.; Keeling, Aiofee; Phade, Sachin V.; Morasch, Mark D.; Kibbe, Melina R.; Eskandari, Mark K.

    2012-04-15

    Purpose: Late stent fatigue is a known complication after carotid artery stenting (CAS) for cervical carotid occlusive disease. The purpose of this study was to determine the prevalence and clinical significance of carotid stent fractures. Materials and Methods: A single-center retrospective review of 253 carotid bifurcation lesions treated with CAS and mechanical embolic protection from April 2001 to December 2009 was performed. Stent integrity was analyzed by two independent observers using multiplanar cervical plain radiographs with fractures classified into the following types: type I = single strut fracture; type II = multiple strut fractures; type III = transverse fracture; and type IV = transverse fracture with dislocation. Mean follow-up was 32 months. Results: Follow-up imaging was completed on 106 self-expanding nitinol stents (26 closed-cell and 80 open-cell stents). Eight fractures (7.5%) were detected (type I n = 1, type II n = 6, and type III n = 1). Seven fractures were found in open-cell stents (Precise n = 3, ViVEXX n = 2, and Acculink n = 2), and 1 fracture was found in a closed-cell stent (Xact n = 1) (p = 0.67). Only a previous history of external beam neck irradiation was associated with fractures (p = 0.048). No associated clinical sequelae were observed among the patients with fractures, and only 1 patient had an associated significant restenosis ({>=}80%) requiring reintervention. Conclusions: Late stent fatigue after CAS is an uncommon event and rarely clinically relevant. Although cell design does not appear to influence the occurrence of fractures, lesion characteristics may be associated risk factors.

  20. The External Degree.

    ERIC Educational Resources Information Center

    Houle, Cyril O.

    This book examines the external degree in relation to the extremes of attitudes, myths, and data. Emphasis is placed on the emergence of the American external degree, foreign external-degree programs, the purpose of the external degree, the current scene, institutional issues, and problems of general policy. (MJM)

  1. Biomechanics of external fixation and limb lengthening.

    PubMed

    Younger, Alastair S E; Morrison, James; MacKenzie, William G

    2004-09-01

    Surgeons who use external fixators for foot and ankle conditions need to understand the biomechanical principles to ensure good outcomes. Fixators can be used for fracture fixation, correction of contractures, distraction osteogenesis, and distraction arthroplasty. A two-ring fixator with wire fixation remains the gold standard with which all other frames are compared. Small changes in mechanical characteristics can have major implications on new bone or cartilage formation.

  2. [Atlas burst fracture (Jefferson fracture) requiring surgical treatment after conservative treatment--report of two cases].

    PubMed

    Yamamoto, Hiromichi; Kurimoto, Masanori; Hayashi, Nakamasa; Ohmori, Tomoaki; Hirashima, Yutaka; Endo, Shunro

    2002-09-01

    Most cases of atlas burst fracture do not require surgical stabilization, because they can be successfully treated with external immobilization. The authors present two cases of atlas burst fracture in which surgical stabilization was required after external immobilization. The first patient was a 50-year-old male and the second patient was a 34-year-old male. Both presented with neck pain without neurological symptoms after a traffic accident. Neuroradiological examinations revealed atlas burst fracture in both patients. They were initially treated with conservative treatment; one with a rigid collar and the other with a halo vest. However, lateral offset of the atlas on the axis increased and atlanto-axial instability became evident three months later in both patients. They underwent upper cervical arthrodesis with satisfactory results. The authors review surgical indication and its timing in patients with atlas burst fracture.

  3. Fracture Mechanics

    DTIC Science & Technology

    1974-01-31

    2219 -T851 aluminum (fractures at low stresses). The parameter KF is alloy compact specimens 1 2 and demonstrate consistent a function of specimen...Congress of 20. Walker, E. K., "The Effect of Stress Ratio Applied Mechanics, 1924. During Crack Propagation and Fatigue for 2024-T3 and 7015- T6 Aluminum ...34Stress- Corrosion Cracking in 12. Kaufman, J. G., and Nelson, F. G., "More Ti-6A1-4V Titanium Alloy in Nitrogen Tetroxide," on Specimen Size Effect in 2219

  4. Splinting of Longitudinal Fracture: An Innovative Approach.

    PubMed

    Bansal, Rashmi; Chowdhary, Priyanka; Gurtu, Anuraag; Mehrotra, Nakul; Kishore, Abhinav

    2016-01-01

    Trauma may result in craze lines on the enamel surface, one or more fractured cusps of posterior teeth, cracked tooth syndrome, splitting of posterior teeth, and vertical fracture of root. Out of these, management of some fractures is of great challenge and such teeth are generally recommended for extraction. Literature search reveals attempts to manage such fractures by full cast crown, orthodontic wires, and so forth, in which consideration was given to extracoronal splinting only. However, due to advancement in materials and technologies, intracoronal splinting can be achieved as well. In this case report, longitudinal fractures in tooth #27, tooth #37, and tooth #46 had occurred. In #27, fracture line was running mesiodistally involving the pulpal floor resulting in a split tooth. In teeth 37 and 46, fractures of the mesiobuccal cusp and mesiolingual cusp were observed, respectively. They were restored with cast gold inlay and full cast crown, respectively. Longitudinal fracture of 27 was treated with an innovative approach using intracanal reinforced composite with Ribbond, external reinforcement with an orthodontic band, and full cast metal crown to splint the split tooth.

  5. Splinting of Longitudinal Fracture: An Innovative Approach

    PubMed Central

    Bansal, Rashmi; Chowdhary, Priyanka; Gurtu, Anuraag; Mehrotra, Nakul; Kishore, Abhinav

    2016-01-01

    Trauma may result in craze lines on the enamel surface, one or more fractured cusps of posterior teeth, cracked tooth syndrome, splitting of posterior teeth, and vertical fracture of root. Out of these, management of some fractures is of great challenge and such teeth are generally recommended for extraction. Literature search reveals attempts to manage such fractures by full cast crown, orthodontic wires, and so forth, in which consideration was given to extracoronal splinting only. However, due to advancement in materials and technologies, intracoronal splinting can be achieved as well. In this case report, longitudinal fractures in tooth #27, tooth #37, and tooth #46 had occurred. In #27, fracture line was running mesiodistally involving the pulpal floor resulting in a split tooth. In teeth 37 and 46, fractures of the mesiobuccal cusp and mesiolingual cusp were observed, respectively. They were restored with cast gold inlay and full cast crown, respectively. Longitudinal fracture of 27 was treated with an innovative approach using intracanal reinforced composite with Ribbond, external reinforcement with an orthodontic band, and full cast metal crown to splint the split tooth. PMID:27247808

  6. Radial head fracture - aftercare

    MedlinePlus

    Elbow fracture - radial head - aftercare ... to 2 weeks. If you have a small fracture and your bones did not move around much, ... to see a bone doctor (orthopedic surgeon). Some fractures require surgery to: Insert pins and plates to ...

  7. Hand fracture - aftercare

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000552.htm Hand fracture - aftercare To use the sharing features on ... need to be repaired with surgery. Types of Hand Fractures Your fracture may be in one of ...

  8. Characterization and Management of Mandibular Fractures: Lessons Learned from Iraq and Afghanistan

    DTIC Science & Technology

    2013-03-01

    external environment12 Compound (open)dfracture in which an external wound, involving skin, mucosa, or periodontal membrane, communicates with the...fractured Pathologicdfracture occurring due to presence of disease Multipled2 or more lines of fracture on the same bone not communicating with each

  9. Chopart fractures.

    PubMed

    Klaue, Kaj

    2004-09-01

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

  10. [Therapy principles of distal fractures of the forearm in childhood].

    PubMed

    Laurer, H; Sander, A; Wutzler, S; Walcher, F; Marzi, I

    2009-11-01

    Fractures of the forearm in children represent one of the most frequent injuries. Most are monotraumatic occurring during sport or leisure activities. Diagnosis can be made by conventional X-ray examination in 2 planes. Distal forearm fractures are classified into epiphyseolysis and epiphyseal fractures, metaphyseal greenstick and buckle fractures, complete distal radius and forearm fractures as well as Galeazzi lesions. The vast majority of cases without relevant dislocation can be treated with immobilization employing a cast. The remaining fractures have to be repositioned and restored depending on age and degree of dislocation.The state of the art in surgical therapy is the Kirschner wire osteosynthesis after closed reduction. Especially meta-diaphyseal fractures can alternatively be stabilized with plate osteosynthesis or external fixation. Following these therapeutic principles, prognosis is excellent and most of the injuries heal without any functional impairment.

  11. Treatment of complex tibial fractures in children with the taylor spatial frame.

    PubMed

    Eidelman, Mark; Katzman, Alexander

    2008-10-01

    Most tibial shaft fractures in children can be treated with closed reduction and cast fixation, but some fractures need external or internal fixation. The Taylor spatial frame (Smith & Nephew, Memphis, Tennessee) is a relatively new external fixator that can correct 6-axis deformities with computer accuracy. This article reports our experience using the Taylor spatial frame as a rewarding treatment modality for complex tibial fractures in children and adolescents.

  12. Operative treatment of distal radius fractures.

    PubMed

    Vasenius, J

    2008-01-01

    The incidence of distal radius fractures is increasing together with the average age of population. Intra-articular incongruity is the most probable cause of unsatisfactory outcome of distal radius fractures in younger and more active patients. Thus, the main goal in the treatment of distal radius fractures should be restoration of articular congruence. A computed tomography (CT) is recommended to help surgeon in preoperative planning in the treatment of comminuted intra-articular fractures. New implants have been designed to provide stable enough fixation for early mobilisation after surgery and to lower rather high complication rates related to conventional fixation methods such as external fixation and dorsal plating. The most common complications related to volar fixed angle plating such as flexor and extensor tendon problems, median nerve neuropathy, and screw diplacement into the radiocarpal joint are surgeon related and are avoidable with proper education. More randomized prospective studies are needed to prove superiority of any fixation method to another.

  13. Animal models of external traumatic wound infections

    PubMed Central

    Dai, Tianhong; Kharkwal, Gitika B; Tanaka, Masamitsu; Huang, Ying-Ying; Bil de Arce, Vida J

    2011-01-01

    Background: Despite advances in traumatic wound care and management, infections remain a leading cause of mortality, morbidity and economic disruption in millions of wound patients around the world. Animal models have become standard tools for studying a wide array of external traumatic wound infections and testing new antimicrobial strategies. Results: Animal models of external traumatic wound infections reported by different investigators vary in animal species used, microorganism strains, the number of microorganisms applied, the size of the wounds and for burn infections, the length of time the heated object or liquid is in contact with the skin. Methods: This review covers experimental infections in animal models of surgical wounds, skin abrasions, burns, lacerations, excisional wounds and open fractures. Conclusions: As antibiotic resistance continues to increase, more new antimicrobial approaches are urgently needed. These should be tested using standard protocols for infections in external traumatic wounds in animal models. PMID:21701256

  14. External artery heat pipe

    NASA Technical Reports Server (NTRS)

    Gernert, Nelson J. (Inventor); Ernst, Donald M. (Inventor); Shaubach, Robert M. (Inventor)

    1989-01-01

    An improved heat pipe with an external artery. The longitudinal slot in the heat pipe wall which interconnects the heat pipe vapor space with the external artery is completely filled with sintered wick material and the wall of the external artery is also covered with sintered wick material. This added wick structure assures that the external artery will continue to feed liquid to the heat pipe evaporator even if a vapor bubble forms within and would otherwise block the liquid transport function of the external artery.

  15. Effect of Natural Fractures on Hydraulic Fracturing

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  16. Fracture channel waves

    NASA Astrophysics Data System (ADS)

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

    1999-03-01

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

  17. [Bone fracture and the healing mechanisms. The mechanical stress for fracture healing in view of distraction osteogenesis].

    PubMed

    Yukata, Kiminori; Takahashi, Mitsuhiko; Yasui, Natsuo

    2009-05-01

    It is generally accepted that moderate mechanical stress influences the course of fracture healing. A flexible fixation of the fractured site can induce fracture callus formation, whereas an unstable fixation can lead to a nonunion. The relationship between mechanical stress and the process of bone regeneration or healing remains incompletely understood. Distraction osteogenesis is a surgical technique that, using appropriate mechanical tension-stress, does not break the callus but rather it stimulates and maintains osteogenesis. The common principles of distraction osteogenesis are osteotomy and slow progressive distraction by an external fixation device. Interest in bone regeneration associated with mechanical stress might lead to better understanding of the fracture healing process.

  18. Humidity-dependent compression-induced glass transition of the air-water interfacial Langmuir films of poly(D,L-lactic acid-ran-glycolic acid) (PLGA).

    PubMed

    Kim, Hyun Chang; Lee, Hoyoung; Jung, Hyunjung; Choi, Yun Hwa; Meron, Mati; Lin, Binhua; Bang, Joona; Won, You-Yeon

    2015-07-28

    Constant rate compression isotherms of the air-water interfacial Langmuir films of poly(D,L-lactic acid-ran-glycolic acid) (PLGA) show a distinct feature of an exponential increase in surface pressure in the high surface polymer concentration regime. We have previously demonstrated that this abrupt increase in surface pressure is linked to the glass transition of the polymer film, but the detailed mechanism of this process is not fully understood. In order to obtain a molecular-level understanding of this behavior, we performed extensive characterizations of the surface mechanical, structural and rheological properties of Langmuir PLGA films at the air-water interface, using combined experimental techniques including the Langmuir film balance, X-ray reflectivity and double-wall-ring interfacial rheometry methods. We observed that the mechanical and structural responses of the Langmuir PLGA films are significantly dependent on the rate of film compression; the glass transition was induced in the PLGA film only at fast compression rates. Surprisingly, we found that this deformation rate dependence is also dependent on the humidity of the environment. With water acting as a plasticizer for the PLGA material, the diffusion of water molecules through the PLGA film seems to be the key factor in the determination of the glass transformation properties and thus the mechanical response of the PLGA film against lateral compression. Based on our combined results, we hypothesize the following mechanism for the compression-induced glass transformation of the Langmuir PLGA film; (1) initially, a humidified/non-glassy PLGA film is formed in the full surface-coverage region (where the surface pressure shows a plateau) during compression; (2) further compression leads to the collapse of the PLGA chains and the formation of new surfaces on the air side of the film, and this newly formed top layer of the PLGA film is transiently glassy in character because the water evaporation rate

  19. History of the treatment of scapula fractures.

    PubMed

    Bartonícek, Jan; Cronier, Patrick

    2010-01-01

    The history of treatment of scapula fractures is closely connected with the history of the French surgery. Paré (Les œuvres d´Ambroise Paré, conseiller, et premier chirurgien du Roy, Gabriel Buon, Paris, p VCV, 1579), Petit (Traité des maladies des os. Tome second, Charles-Etienne Hochereau, Paris, pp 122–138, 1723), Du Verney (Traité des maladies des os. Tome I, de Burre, Paris, pp 220–231, 1751) and Desault (Œuvres chirurgicales, ou tableau de la doctrine et de la pratique dans le traitement des maladies externes par Xav. Bichat, Desault, Méquignon, Devilliers, Deroi, Paris, pp 98–106, 1798) were the first to point out the existence of these fractures. The first drawing of a scapula fracture was presented by Vogt (Dissertatio de ambarum scapularum dextroeque simul claviculae fractura rara, Dissertatione Universitae Vitembergensi, Wittenberg, 1799). This author was also the first to describe the scapula fracture associated with ipsilateral fracture of the clavicle. The first radiograph of scapula fracture (glenoid fossa fracture) was published by Struthers (Edinburgh Med J 4(3):147–149, 1910). The first internal fixation of scapula fracture using plate was done by Lambotte (1910) who was followed by Lane (The operative treatment of fractures, Medical Publishing Co, London, pp 99–101, 1914) and later by Lenormant (Sur l´ostéosynthèse dans certains fractures de l´omoplate Bulletins et mémoires de la Société de chirgie de Paris, pp 1501–1502, 1923), Dujarier (Fracture du col chirgical de l´omoplate. Ostéosynthèse par plaque en T. Bonne réduction. Bulletin et mémoires de la Société de chirurgie de Paris, pp 1492–1493, 1923) and Basset (Ostéosynthèse d´une fracture de l´omoplate. Bulletin et mémoires de la Société nationale de chirurgie. p 193, 1924). Dupont and Evrard (J Chir (Paris) 39:528–534, 1932) presented the first detailed description of the surgical approach along the lateral border of the scapula including two

  20. Fracture dynamics in implanted silicon

    SciTech Connect

    Massy, D.; Tardif, S.; Penot, J. D.; Ragani, J.; Rieutord, F.; Mazen, F.; Madeira, F.; Landru, D.; Kononchuk, O.

    2015-08-31

    Crack propagation in implanted silicon for thin layer transfer is experimentally studied. The crack propagation velocity as a function of split temperature is measured using a designed optical setup. Interferometric measurement of the gap opening is performed dynamically and shows an oscillatory crack “wake” with a typical wavelength in the centimetre range. The dynamics of this motion is modelled using beam elasticity and thermodynamics. The modelling demonstrates the key role of external atmospheric pressure during crack propagation. A quantification of the amount of gas trapped inside pre-existing microcracks and released during the fracture is made possible, with results consistent with previous studies.

  1. [Periprosthetic Acetabulum Fractures].

    PubMed

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

    2016-12-01

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

  2. External radiation surveillance

    SciTech Connect

    Antonio, E.J.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report describes how external radiation was measured, how surveys were performed, and the results of these measurements and surveys. External radiation exposure rates were measured at locations on and off the Hanford Site using thermoluminescent dosimeters (TLD). External radiation and contamination surveys were also performed with portable radiation survey instruments at locations on and around the Hanford Site.

  3. A universal fracture criterion for high-strength materials

    PubMed Central

    Qu, Rui Tao; Zhang, Zhe Feng

    2013-01-01

    Recently developed advanced high-strength materials like metallic glasses, nanocrystalline metallic materials, and advanced ceramics usually fracture in a catastrophic brittle manner, which makes it quite essential to find a reasonable fracture criterion to predict their brittle failure behaviors. Based on the analysis of substantial experimental observations of fracture behaviors of metallic glasses and other high-strength materials, here we developed a new fracture criterion and proved it effective in predicting the critical fracture conditions under complex stress states. The new criterion is not only a unified one which unifies the three classical failure criteria, i.e., the maximum normal stress criterion, the Tresca criterion and the Mohr-Coulomb criterion, but also a universal criterion which has the ability to describe the fracture mechanisms of a variety of different high-strength materials under various external loading conditions.

  4. [Fractures of the forefoot].

    PubMed

    Richter, M

    2011-10-01

    Fractures of the forefoot are common and comprise approximately two thirds of all foot fractures. Forefoot fractures are caused by direct impact or the effect of indirect force. The forces exerted can range from repetitive minor load (stress fractures) to massive destructive forces (complex trauma). The clinical course in forefoot fractures is typically more favourable than in fractures of the mid- and hindfoot. The incidence of complications like infection or pseudarthrosis is low. Exceptions are rare fractures of the proximal shaft of the fifth metatarsal and the sesamoids with higher pseudarthrosis rates. Malunited metatarsal fractures can cause painful conditions that should even be treated operatively. Differences in structure and function of the different forefoot areas and specific fracture types require an adapted management of these special injuries.

  5. Management of metacarpal fractures.

    PubMed

    McNemar, Thomas B; Howell, Julianne Wright; Chang, Eric

    2003-01-01

    Fractures of the hand are the most common fractures of the human skeleton. Metacarpal fractures account for 30% to 50% of all of hand fractures. The mechanisms of these injuries vary from axial loading forces to direct blows to the dorsal hand. Resulting deformities include malrotation, angulation, and shortening. Treatment modalities vary from nonoperative reduction to open reduction and internal fixation. The treatment algorithm is guided by the location of the fracture, the stability of the fracture, and the resultant deformity. Operative procedures, although they may lead to excellent radiographic reduction of fractures, often lead to debilitating stiffness from the inflammatory reaction of the surgical procedure. Operative fixation must be employed judiciously and offered only when confident that non-operative therapy can be improved on with operative intervention. This article reviews the various types of metacarpal fractures, with the treatment options available for each fracture. The indications for each treatment modality, postoperative care, and rehabilitation are presented.

  6. Taylor Spatial Frame in the treatment of pediatric and adolescent tibial shaft fractures.

    PubMed

    Al-Sayyad, Mohammed J

    2006-01-01

    The Taylor Spatial Frame (TSF) is a modern multiplanar external fixator that combines ease of application plus computer accuracy in the reduction of fractures. A retrospective review of our experience in using this device for treating unstable tibia fractures in pediatric and adolescent patients was carried out to determine the effectiveness and complications of TSF in the treatment of these fractures. Ten tibia fractures were included. All patients were boys with an average age of 12 years (range 8-15 years). Mean duration of follow-up was 3.1 years. These fractures included 5 open fractures. All fractures healed over a mean of 18 weeks. All patients were doing well and involved in sports when last seen. Postoperative complications included pin tract infection in 5 patients. TSF is an effective definitive method of tibia fracture care with the advantage of early mobilization and ability to postoperatively manipulate fracture into excellent alignment.

  7. TREATMENT OF DIFFICULT AND INVOLVED COLLES' FRACTURES

    PubMed Central

    Cox, Francis J.; Meier, August W.

    1951-01-01

    Of 105 cases of Colles' fracture, 86 were treated by closed reduction and plaster immobilization alone; 19 cases in which the fractures were more severe were treated by fixed skeletal traction using an external skeletal traction splint. Despite the greater severity of the lesions, the end results, both anatomic and functional, were generally better in those cases in which skeletal traction was used than in those treated by closed reduction. ImagesFigure 1.Figure 2.Figure 3.Figure 4.Figure 5.Figure 6.Figure 7.Figure 8.Figure 9.Figure 10.Figure 11.Figure 12.Figure 13. PMID:14801716

  8. On material fracture criteria

    NASA Astrophysics Data System (ADS)

    Kremnev, L. S.

    2017-01-01

    Based on the nonlinear mechanics of material fracture, a model of the fracture of materials with actual (discrete) structures has been constructed. The model is supported by proofs that crack resistance K 1 c and fracture toughness G 1 c obtained from the energy conservation law without using the assumptions adopted in the linear material fracture mechanics serve as the force and energy criteria in the nonlinear fracture mechanics. It has been shown that energy criterion G 1 c in the nonlinear mechanics is much greater than G 1 c in the linear fracture mechanics.

  9. Pilon fracture: a case report of a 45-year-old dental technician.

    PubMed

    Mafi, Pouya; Stanley, James; Hindocha, Sandip; Mafi, Reza

    2014-01-01

    Pilon fractures are complex and difficult-to-treat fractures of the lower extremity that account for about 1% of all lower extremity fractures and up to 10% of tibial fractures. The injury is caused by high energy axial load either from motor vehicle accidents or a fall from height. The treatment of these fractures has caused controversy among surgeons due to mixed outcomes. Here we report a case of pilon fracture in a 45 year old male patient who has sustained the injury as a result of a fall from a height of approximately 12 feet. We describe why it is absolutely crucial that the patient is treated with external fixation initially and evaluate its merits and drawbacks as well as ways to minimize the complications associated with external fixation of open intra-articular distal tibial fractures.

  10. External approach to rhinoplasty.

    PubMed

    Goodman, Wilfred S; Charbonneau, Paul A

    2015-07-01

    The technique of external rhinoplasty is outlined. Having reviewed 74 cases, its advantages and disadvantages are discussed. Reluctance to use this external approach seems to be based on emotional rather than radical grounds, for its seems to be the procedure of choice for many problems.

  11. [Fractures of the shaft of the femur].

    PubMed

    Lögters, T; Windolf, J; Flohé, S

    2009-07-01

    The femur is the largest, longest and strongest bone in the human skeleton. Fractures of the shaft of the femur can result from high energy as well as low energy trauma and 30% of patients have multiple injuries. In the clinical diagnostic special attention must be paid to the peripheral neurovascular status as well as the possibility of a compartment syndrome. Fractures of the femur shaft are defined according to the AO classification. Treatment is as a rule operative, except for children up the end of 4 years old. Medullary nailing is nowadays the method of choice and the nails can be implanted in an anterograde or retrograde direction. The introduction of nails after boring out the medullar is associated with an increased healing rate in comparison to non-boring techniques. Various techniques are available for the often promising method of repositioning and the intraoperative controls. Plating is reserved only for special situations. External fixation is of great value in adults for temporary fixation of fractures of the femur shaft. Full weight bearing is possible immediately following the operation depending on the type of fracture and method of treatment. Uncomplicated fracture healing does not result in a reduction in the ability to work. Despite the generally good prognosis and improvement in design and technology of implants, fractures of the femur shaft still represent a special challenge for the treating casualty surgeon.

  12. Compendium of fracture mechanics problems

    NASA Technical Reports Server (NTRS)

    Stallworth, R.; Wilson, C.; Meyers, C.

    1990-01-01

    Fracture mechanics analysis results are presented from the following structures/components analyzed at Marshall Space Flight Center (MSFC) between 1982 and 1989: space shuttle main engine (SSME), Hubble Space Telescope (HST), external tank attach ring, B-1 stand LOX inner tank, and solid rocket booster (SRB). Results from the SSME high pressure fuel turbopump (HPFTP) second stage blade parametric analysis determine a critical flaw size for a wide variety of stress intensity values. The engine 0212 failure analysis was a time dependent fracture life assessment. Results indicated that the disk ruptured due to an overspeed condition. Results also indicated that very small flaws in the curvic coupling area could propagate and lead to failure under normal operating conditions. It was strongly recommended that a nondestructive evaluation inspection schedule be implemented. The main ring of the HST, scheduled to launch in 1990, was analyzed by safe-life and fail-safe analyses. First safe-life inspection criteria curves for the ring inner and outer skins and the fore and aft channels were derived. Afterwards the skins and channels were determined to be fail-safe by analysis. A conservative safe-life analysis was done on the 270 redesign external tank attach ring. Results from the analysis were used to determine the nondestructive evaluation technique required.

  13. Metatarsal stress fractures - aftercare

    MedlinePlus

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

  14. Infant skull fracture (image)

    MedlinePlus

    Skull fractures may occur with head injuries. Although the skull is both tough and resilient and provides excellent ... or blow can result in fracture of the skull and may be accompanied by injury to the ...

  15. Rib fracture - aftercare

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000539.htm Rib fracture - aftercare To use the sharing features on this page, please enable JavaScript. A rib fracture is a crack or break in one or ...

  16. Forearm Fractures in Children

    MedlinePlus

    .org Forearm Fractures in Children The forearm is the part of the arm between the wrist and the elbow. It is ... two bones: the radius and the ulna. Forearm fractures are common in childhood, accounting for more than ...

  17. Pediatric Thighbone (Femur) Fracture

    MedlinePlus

    .org Thighbone (Femur) Fractures In Children Page ( 1 ) The thighbone (femur) is the largest and strongest bone in the body. It can break ... Cause Statistics The most common cause of thighbone fractures in infants under 1 year old is child ...

  18. Nasal fracture (image)

    MedlinePlus

    A nasal fracture is a break in the bone over the ridge of the nose. It usually results from a blunt ... and is one of the most common facial fracture. Symptoms of a broken nose include pain, blood ...

  19. Bone fracture repair - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100077.htm Bone fracture repair - series—Indications To use the sharing features ... Go to slide 4 out of 4 Overview Fractures of the bones are classified in a number ...

  20. Femur fracture repair - discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000166.htm Femur fracture repair - discharge To use the sharing features on this page, please enable JavaScript. You had a fracture (break) in the femur in your leg. It ...

  1. Lisfranc (Midfoot) Fractures

    MedlinePlus

    ... that disrupts multiple different joints and includes multiple fractures. Lisfranc injuries tend to damage the cartilage of ... include ligament strains and tears, as well as fractures and dislocations of bone (far right). (Le ) This ...

  2. Growth Plate Fractures

    MedlinePlus

    .org Growth Plate Fractures Page ( 1 ) The bones of children and adults share many of the same risks for injury. But because they ... to a unique injury called a growth plate fracture. Growth plates are areas of cartilage located near ...

  3. Hip fracture surgery

    MedlinePlus

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

  4. Fracture patterns in the Zagros fold-and-thrust belt, Kurdistan Region of Iraq

    NASA Astrophysics Data System (ADS)

    Reif, Daniel; Decker, Kurt; Grasemann, Bernhard; Peresson, Herwig

    2012-11-01

    Fracture data have been collected in the Kurdistan Region of Iraq, which is a poorly accessible and unexplored area of the Zagros. Pre to early folding NE-SW striking extensional fractures and NW-SE striking contractive elements represent the older set affecting the exposed multilayer of the area. These latter structures are early syn-folding and followed by folding-related mesostructural assemblages, which include elements striking parallel to the axial trend of major folds (longitudinal fractures). Bedding perpendicular joints and veins, and extensional faults belonging to this second fracture set are located in the outer arc of exposed anticlines, whilst longitudinal reverse faults locate in the inner arcs. Consistently, these elements are associated with syn-folding tangential longitudinal strain. The younger two sets are related to E-W extension and NNE-SSW to N-S shortening, frequently displaying reactivation of the older sets. The last shortening event, which is described along the entire Zagros Belt, probably relates with the onset of N-S compression induced by the northward movement of the Arabian plate relative to the Eurasian Plate. In comparison between the inferred palaeostrain directions and the kinematics of recent GPS measurements, we conclude that the N-S compression and the partitioning into NW-SE trending folds and NW to N trending strike-slip faults likely remained unchanged throughout the Neogene tectonic history of the investigated area.

  5. Orbital fractures: a review

    PubMed Central

    Joseph, Jeffrey M; Glavas, Ioannis P

    2011-01-01

    This review of orbital fractures has three goals: 1) to understand the clinically relevant orbital anatomy with regard to periorbital trauma and orbital fractures, 2) to explain how to assess and examine a patient after periorbital trauma, and 3) to understand the medical and surgical management of orbital fractures. The article aims to summarize the evaluation and management of commonly encountered orbital fractures from the ophthalmologic perspective and to provide an overview for all practicing ophthalmologists and ophthalmologists in training. PMID:21339801

  6. [Epidemiological view of fracture risk].

    PubMed

    Fujiwara, Saeko

    2010-09-01

    Incidence of hip fracture increases exponentially with age. Women had two times higher hip fracture incidence than men. Major risk factors for the hip fracture are age, sex, bone mineral density, and previous fracture and others, but each risk factor contributes differently to development of the fracture by sites. Factors related to fall are important role in developing hip fracture.

  7. [Osteoporosis and Colles' fracture].

    PubMed

    Hindsø, K; Lauritzen, J B

    2001-10-01

    We describe the connection between osteoporosis and Colles' fractures of the distal radius from an epidemiological and aetiological point of view. In addition, the value of these fractures as markers of osteoporosis and future risk of fracture is assessed. Several studies have clearly shown an epidemiological association between osteoporosis and fractures of the distal radius, with the association strongest for women up to 65 years of age and for osteoporosis located in the forearm. The association weakens for other locations and for older women. Osteoporosis may have some aetiologic significance for the development of Colles' fractures, but several extraskeletal factors are of equal or further importance. The occurrence of a Colles' fracture in the first 10-15 years after the postmenopause indicates an increased relative risk of sustaining another fracture in the future. However the relative risk approaches one after a few years and, because of the comparatively low absolute risk in this age-group, Colles' fracture as a risk factor contributes little to an assessment of the lifetime fracture risk. In a few longitudinal studies, Colles' fractures could not predict the long-term risk of osteoporosis. The presence of a Colles' fracture should lead to considerations concerning the skeletal and extraskeletal causes of the fracture for the purpose of initiating preventive and therapeutic measures.

  8. Elbow fractures and dislocations.

    PubMed

    Little, Kevin J

    2014-07-01

    Elbow fractures are common in pediatric patients. Most injuries to the pediatric elbow are stable and require simple immobilization; however, more severe fractures can occur, often requiring operative stabilization and/or close monitoring. This article highlights the common fractures and dislocations about the pediatric elbow and discusses the history, evaluation, and treatment options for specific injuries.

  9. [Surgical treatment of subtrochanteric fractures in children].

    PubMed

    Guzmán-Vargas, R; Rincón-Cardozo, D F; Camacho-Casas, J A

    2016-01-01

    Subtrochanteric fractures in children are rare events, occur in only 4% of all femur fractures, most injuries occur as a result of high energy trauma, being young males patient the most affected. The management of this type of injury is controversial, there are many forms of treatment, including the use of plaster spica 90-90, closed reduction and use of elastic or rigid intramedullary nails, open reduction and plate placement and external fixators. Most suggest that children under 10 should be preferred non-operative and for older than 12 surgical management is indicated, but the discussion is between 6 and 12 years old. Through this article we present the treatment of such entity with a proximal fracture plate using a minimally invasive technique.

  10. The development of a novel model of direct fracture healing in the rat

    PubMed Central

    Savaridas, T.; Wallace, R. J.; Muir, A. Y.; Salter, D. M.; Simpson, A. H. R. W.

    2012-01-01

    Objectives Small animal models of fracture repair primarily investigate indirect fracture healing via external callus formation. We present the first described rat model of direct fracture healing. Methods A rat tibial osteotomy was created and fixed with compression plating similar to that used in patients. The procedure was evaluated in 15 cadaver rats and then in vivo in ten Sprague-Dawley rats. Controls had osteotomies stabilised with a uniaxial external fixator that used the same surgical approach and relied on the same number and diameter of screw holes in bone. Results Fracture healing occurred without evidence of external callus on plain radiographs. At six weeks after fracture fixation, the mean stress at failure in a four-point bending test was 24.65 N/mm2 (sd 6.15). Histology revealed ‘cutting-cones’ traversing the fracture site. In controls where a uniaxial external fixator was used, bone healing occurred via external callus formation. Conclusions A simple, reproducible model of direct fracture healing in rat tibia that mimics clinical practice has been developed for use in future studies of direct fracture healing. PMID:23610660

  11. A locked hip screw-intramedullary nail (cephalomedullary nail) for the treatment of fractures of the proximal part of the femur combined with fractures of the femoral shaft.

    PubMed

    Alho, A; Ekeland, A; Grøgaard, B; Dokke, J R

    1996-01-01

    Twenty-seven patients with complex femoral fractures (combined shaft and proximal femoral fractures) were treated with a modified Grosse-Kempf slotted locking nail (cephalomedullary nail), wherein two screws were inserted in the hip. Four types of complex, multifocal femoral fractures were represented in the series. Eleven of the femoral shaft fractures were secondary to a previous, internally fixed, not yet united hip fracture (type I). Ten comminuted peritrochanteric fractures occurred in normal bone (type II). Three similar fractures were pathologic because of metastasis. Two patients had an ipsilateral fracture of the femoral shaft and the trochanteric area (type III), and one of the shaft and the femoral neck (type IV). Locking was made static in 24 cases. Additional cerclage wiring was used in three type II fractures. Five complications were as follows: one cutting out of a screw in the femoral head, two fractures of the nail, one deep venous thrombosis, and one wound hematoma. Reoperations were two salvage operations using a new nail and one evacuation of hematoma. One patient with multiple injuries and four elderly patients died within 2 months. Eighteen patients with fractures in normal bone were followed for a median of 20 (6 to 37) months. All fractures united. Two nails were removed. The end result was excellent in ten patients, good in seven, and fair in one (2-cm shortening and 20-degree external rotation). We conclude that a locked intramedullary construct with locking screws in femoral neck and distal femur controls a complex fracture situation well.

  12. Future of External Reporting

    ERIC Educational Resources Information Center

    Powers, Kristina

    2015-01-01

    This chapter builds on prior chapters and focuses on higher education trends on the horizon and the resulting impact on external reporting for institutional researchers. Three practical recommendations and examples for institutional researchers are also presented.

  13. In-vitro Evaluation of Fracture Strength Recovery of Reattached Anterior Fractured Tooth Fragment Using Different Re-Attachment Techniques

    PubMed Central

    Abdulkhayum, Abdulmujeeb; Munjal, Sumit; Babaji, Prashant; Chaurasia, Vishwajit Rampratap; Munjal, Seema; Lau, Himani; Olekar, Santosh T; Lau, Mayank

    2014-01-01

    Background: Traumatic injuries caused to anterior teeth are most common. Emergency management of fractured fragments is necessary, for preserving their vitalities and for retaining aesthetics in an economical way. Various methods are available for restoring fractured, uncomplicated teeth, such as reattachment of fractured fragments, composite restoration. But only limited data is available on evaluation of the strength of reattached fractured fragments. Hence, the present study was designed. Objectives: The objective of this study was to evaluate the fracture strength recovery of re-attached anterior fractured tooth fragment by using different re-attachment techniques. Methodology: Forty human upper central incisions were used in this study. The roots of the teeth were confined in a special device (holder) and adapted in a Universal Testing Machine. Load was applied to each tooth in bucco-lingual direction, by using a small stainless steel ball. The force which was required to fracture the tooth was recorded. Both the fragment and remaining fractured tooth was restored by using four reattachment techniques - simple reattachment, external chamfer, over contour and internal dentinal groove. Specimens were loaded in same pre-determined area which was used in procedure to obtain fragments. The force required to detach each fragment was recorded and it was correlated with the fracture strength of an intact tooth and that which was obtained after doing restorative procedures for all groups i.e. fracture strength recovery. Results: Technique I (simple reattachment) and Technique 2 (external chamfer) showed fracture strength recoveries of 44.3% and 60.6% respectively. However, these values were lower than those which were obtained by usingTechnique 3 (Over contour) -86.8% and Technique 4 (internal dentinal groove) -89.5%. Conclusion: Over contour and internal dentinal groove reattachment is a preferred technique as compared to the other reattachment techniques which were

  14. Proximal humerus fractures.

    PubMed

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

    2013-01-01

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

  15. Stress fractures in runners.

    PubMed

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

    2012-04-01

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

  16. Fracture toughness of silicon

    NASA Technical Reports Server (NTRS)

    Chen, C. P.; Leipold, M. H.

    1980-01-01

    The paper presents a study to determine the fracture toughness and to characterize fracture modes of silicon as a function of the orientation of single-crystal and polycrystalline material. It is shown that bar specimens cracked by Knoop microhardness indentation and tested to fracture under four-point bending at room temperature were used to determine the fracture toughness values. It is found that the lowest fracture toughness value of single crystal silicon was 0.82 MN/m to the 3/2 in the 111 plane type orientation, although the difference in values in the 111, 110, and 100 planes was small.

  17. [Rarely seen fractures].

    PubMed

    Subaşi, M; Kapukaya, A; Kesemenli, C; Coban, V

    2001-10-01

    Rarely seen fractures are presented in this study. One case was a calcaneal spur, 2 cases osteochondroma pedicule fractures and talus posteromedial tubercle fracture due to direct trauma. Calcaneal spur and osteochondromas were removed surgically and posteromedial tubercle was treated by short-leg cast immobilization. In conclusion, we think that fractures of osteochondroma and calcaneal spur may be treated by surgical removal which do not cause any functional disorders after this operation, but fractures like the talus posteromedial tubercle should be treated conservatively by short-leg immobilization in the early period.

  18. Enhancement of fracture healing by electrical stimulation in the comminuted intraarticular fracture of distal radius.

    PubMed

    Kohata, Kazuhiro; Itoh, Soichiro; Takeda, Shu; Kanai, Misa; Yoshioka, Taro; Suzuki, Hiroyuki; Yamashita, Kimihiro

    2013-01-01

    Effectiveness of an alternating electric current (AC) stimulation in prevention of bone deformity for comminuted intraarticular fracture of distal radius were verified by comparing postoperative results treated with a wrist-bridging external fixator combined with or without an AC stimulator (EF and NEF, respectively), and a palmar locking plate (LP). This study evaluated 92 cases (mean age 67.9 ± 11.4 years) of type C2 and 60 cases (mean age 69.7 ± 9.5 years) of type C3 distal radius fractures, as classified by the Association for Osteosynthesis. In total, 55 and 24 cases were treated with EF and NEF, respectively; and 73 cases were treated with LP. Callus appeared 27.5 ± 4.6 days postoperatively and the external skeletal fixation period was significantly shorter in the EF group than in the NEF group. The decrease in radial length was significantly lower in the EF group when compared to the LP group. There were no significant differences among the groups for the other radiographic and functional parameters. AC stimulation combined to the external fixation may be a promising method to prevent postoperative deformity in the severely comminuted intraarticular fractures by accelerating callus maturation and facilitating new bone bridging across the gap of fracture site.

  19. Externally modulated theranostic nanoparticles.

    PubMed

    Urban, Cordula; Urban, Alexander S; Charron, Heather; Joshi, Amit

    2013-08-01

    Externally modulated nanoparticles comprise a rapidly advancing class of cancer nanotherapeutics, which combine the favorable tumor accumulation of nanoparticles, with external spatio-temporal control on therapy delivery via optical, magnetic, or ultrasound modalities. The local control on therapy enables higher tumor treatment efficacy, while simultaneously reducing off-target effects. The nanoparticle interactions with external fields have an additional advantage of frequently generating an imaging signal, and thus such agents provide theranostic (both diagnostic and therapeutic) capabilities. In this review, we classify the emerging externally modulated theranostic nanoparticles according to the mode of external control and describe the physiochemical mechanisms underlying the external control of therapy, and illustrate the major embodiments of nanoparticles in each class with proven biological efficacy: (I) electromagnetic radiation in visible and near-infrared range is being exploited for gold based and carbon nanostructures with tunable surface plasmon resonance (SPR) for imaging and photothermal therapy (PTT) of cancer, photochemistry based manipulations are employed for light sensitive liposomes and porphyrin based nanoparticles; (II) Magnetic field based manipulations are being developed for iron-oxide based nanostructures for magnetic resonance imaging (MRI) and magnetothermal therapy; (III) ultrasound based methods are primarily being employed to increase delivery of conventional drugs and nanotherapeutics to tumor sites.

  20. Externally modulated theranostic nanoparticles

    PubMed Central

    Urban, Cordula; Urban, Alexander S.; Charron, Heather; Joshi, Amit

    2013-01-01

    Externally modulated nanoparticles comprise a rapidly advancing class of cancer nanotherapeutics, which combine the favorable tumor accumulation of nanoparticles, with external spatio-temporal control on therapy delivery via optical, magnetic, or ultrasound modalities. The local control on therapy enables higher tumor treatment efficacy, while simultaneously reducing off-target effects. The nanoparticle interactions with external fields have an additional advantage of frequently generating an imaging signal, and thus such agents provide theranostic (both diagnostic and therapeutic) capabilities. In this review, we classify the emerging externally modulated theranostic nanoparticles according to the mode of external control and describe the physiochemical mechanisms underlying the external control of therapy, and illustrate the major embodiments of nanoparticles in each class with proven biological efficacy: (I) electromagnetic radiation in visible and near-infrared range is being exploited for gold based and carbon nanostructures with tunable surface plasmon resonance (SPR) for imaging and photothermal therapy (PTT) of cancer, photochemistry based manipulations are employed for light sensitive liposomes and porphyrin based nanoparticles; (II) Magnetic field based manipulations are being developed for iron-oxide based nanostructures for magnetic resonance imaging (MRI) and magnetothermal therapy; (III) ultrasound based methods are primarily being employed to increase delivery of conventional drugs and nanotherapeutics to tumor sites. PMID:24834381

  1. Subsurface fracture spacing

    SciTech Connect

    Lorenz, J.C. ); Hill, R.E. )

    1991-01-01

    This study was undertaken in order to document and analyze the unique set of data on subsurface fracture characteristics, especially spacing, provided by the US Department of Energy's Slant Hole Completion Test well (SHCT-1) in the Piceance Basin, Colorado. Two hundred thirty-six (236) ft (71.9 m) of slant core and 115 ft (35.1 m) of horizontal core show irregular, but remarkably close, spacings for 72 natural fractures cored in sandstone reservoirs of the Mesaverde Group. Over 4200 ft (1280 m) of vertical core (containing 275 fractures) from the vertical Multiwell Experiment wells at the same location provide valuable information on fracture orientation, termination, and height, but only data from the SHCT-1 core allow calculations of relative fracture spacing. Within the 162-ft (49-m) thick zone of overlapping core from the vertical and deviated wellbores, only one fracture is present in vertical core whereas 52 fractures occur in the equivalent SHCT-1 core. The irregular distribution of regional-type fractures in these heterogeneous reservoirs suggests that measurements of average fracture spacing'' are of questionable value as direct input parameters into reservoir engineering models. Rather, deviated core provides data on the relative degree of fracturing, and confirms that cross fractures can be rare in the subsurface. 13 refs., 11 figs.

  2. Limits of internal fixation in long-bone fracture.

    PubMed

    Nieto, H; Baroan, C

    2017-02-01

    Alternatives to internal fixation of long-bone fracture comprise, depending on location, external fixation or joint replacement. Limitations comprise risk of infection and functional outcome quality, which vary according to technique. The present study examines these limitations, based on comparative or large-scale studies from which certain significant results emerge. Four main questions are dealt with: (1) the present role of locking plates; (2) conditions for intramedullary nailing in Gustilo grade IIIb open fracture; (3) the limitations of conversion from external fixation to intramedullary nailing in open lower leg fracture; (4) and the limitations of definitive anterograde femoral nailing in multiple trauma. Locking plate fixation has yet to prove clinical superiority in any of the anatomic sites for which good-quality comparative analyses are available. Infection risk in Gustilo grade IIIb open lower leg fracture is equivalent when treated by intramedullary nailing or external fixation, if wound care and debridement are effective, antibiotherapy is initiated rapidly and skin cover is restored within 7days. Conversion from primary external fixation to intramedullary nailing is possible if the external fixator was fitted less than 28days previously and skin cover was restored within 7days. The pulmonary and systemic impact of peripheral lesions or definitive anterograde intramedullary nailing of femoral fracture in multiple trauma calls for caution and what is known as "damage-control orthopedics" (DCO), a term covering the general consequences of both the initial trauma and its treatment. Femoral intramedullary nailing is thus contraindicated in case of hemorrhagic shock (blood pressure<90mmHg), hypothermia (<33°C), coagulation disorder (platelet count<90,000) or peripheral lesions such as multiple long-bone fractures, crushed limb or primary pulmonary contusion. In such cases, external fixation or retrograde nailing with a small-diameter nail and without

  3. Atraumatic sternum fracture

    PubMed Central

    Abrahamsen, Sebastian Ørskov; Madsen, Christina Friis

    2014-01-01

    The spine, pelvic bones and long bones of the lower extremities are common sites for insufficiency fractures. Cases of sternum insufficiency fractures have rarely been reported among elderly patients. Insufficiency fractures tend to occur in bones with decreased mechanical strength especially among elderly patients, in postmenopausal women and patients with underlying diseases. We describe a case of spontaneous sternum insufficiency fracture in a healthy man, with no known risk factors to fracture, or previous history of fractures. Sternum insufficiency fracture is a rare cause of chest pain. This case serves to remind the emergency physician to remain vigilant for other non-cardiac, non-pulmonary and non-traumatic causes of chest pain, especially among patients with known risk factors such as osteoporosis, chronic obstructive pulmonary disease, rheumatoid arthritis, systemic lupus erythematosus and patients on long-term steroid treatment. If diagnosed correctly, these patients can be discharged and treated as outpatients as this case emphasises. PMID:25326566

  4. Mechanics of Hydraulic Fractures

    NASA Astrophysics Data System (ADS)

    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.

  5. Landing on your own two feet: a case report of bilateral calcaneus and open pilon fractures.

    PubMed

    Tiedeken, Nathan C; Hampton, David; Shaffer, Gene

    2014-01-01

    High energy fractures of the distal tibial plafond and calcaneus have been associated with high functional morbidity and wound complications. Although both of these fractures result from a similar mechanism, they have rarely been reported to occur on an ipsilateral extremity. The combination of these 2 injuries on the same extremity would increase the likelihood of an adverse surgical or functional outcome. We present the case and management strategy of a 43-year-old male with bilateral open pilon fractures and closed calcaneal fractures after falling from a height. A staged protocol was used for the bilateral pilon fractures, with external fixation until operative fixation on day 9. Nonoperative management of the calcaneal fractures resulted in a successful functional outcome at 10 months of follow-up. Treatment of this fracture pattern must incorporate the condition of the soft tissues, an understanding of the fractures, and minimize patient risk factors to optimize the functional and surgical outcomes.

  6. Do Kirschner wires maintain reduction of displaced Colles' fractures?

    PubMed

    Barton, Tristan; Chambers, Charles; Lane, Emma; Bannister, Gordon

    2005-12-01

    Fifty-three patients underwent closed reduction and longitudinal k-wiring of displaced Colles' fractures and were reviewed after a mean of 26 months. Radiographs taken at the time of injury, after reduction and k-wiring, and at fracture union were compared for radial shortening and dorsal angulation. Manipulation significantly improved fracture position (P<0.001). Dorsal angulation was successfully corrected by manipulation in 98%, and this position was maintained to fracture union in all cases. Seventy-three percentage of fractures manipulated for radial shortening >2 mm were adequately reduced, but 41% of these fractures subsequently lost position to malunite. In this group of patients, the mean radial shortening between reduction and fracture union was 1.6 mm. This did not correlate with Frykman Class or radial shortening at injury. Closed reduction and k-wire stabilisation is an attractive technique because it is relatively non-invasive compared with plating or external fixation. However, a degree of radial shortening between reduction and fracture union must be anticipated. Fractures reduced inadequately to allow for this loss of radial length, are more likely to malunite. This may compromise functional outcome.

  7. Multiple seizure-induced thoracic vertebral compression fractures: a case report

    PubMed Central

    Stilwell, Peter; Harman, Katherine; Hsu, William; Seaman, Brian

    2016-01-01

    Background: Musculoskeletal injuries stemming from forceful muscular contractions during seizures have been documented in the literature. Reports of multiple seizure-induced spinal fractures, in the absence of external trauma and without risk factors for fracture, are rare. Case Presentation: A 28-year-old male, newly diagnosed with epilepsy, presented to a chiropractic clinic with the complaint of mid-thoracic pain beginning after a tonic-clonic seizure with no associated external trauma. Radiographs revealed the impression of five new vertebral compression fractures from T4 to T8. Discussion: This report highlights the importance of a complete history and examination of patients with a history of tonic-clonic seizures and back pain, especially when considering spinal adjustments. Summary: This case report presents an argument that a tonic-clonic seizure, in the absence of external trauma or significant risk factors for fracture, resulted in multiple vertebral compression fractures. PMID:27713581

  8. Long-bone fractures in llamas and alpacas: 28 cases (1998-2008).

    PubMed

    Knafo, S Emmanuelle; Getman, Liberty M; Richardson, Dean W; Fecteau, Marie-Eve

    2012-07-01

    Treatment and outcome of camelids with long-bone fractures are described. Medical records (1998-2008) of camelids (n = 28) with long-bone fractures were reviewed for signalment, time to presentation, fracture type, method of repair, duration of hospitalization, and post-operative complications. Follow-up information was obtained via telephone interviews with owners. Mean age and weight at presentation were 3.4 years and 56.3 kg, respectively. Twenty-six fractures were treated with internal fixation (n = 11), external fixation (n = 10), combination of internal and external fixation (n = 3), amputation (n = 1), and external fixation followed by amputation (n = 1). Long-term follow-up information was obtained for 19 of the 26 animals. The post-operative complication rate was 23% and owner satisfaction was high. Animals with open fractures were more likely to experience complications. Internal fixation was associated with superior alignment and outcome. Internal fixation techniques should be recommended for camelids.

  9. Maxillary antral bone grafts for repair of orbital fractures.

    PubMed

    Copeland, M; Meisner, J

    1991-04-01

    Use of bone from the maxillary antrum to repair defects in the orbital floor was described more than 20 years ago but has not been reported for correction of orbital rim fractures. The method is appealing because the source is contiguous with the recipient site; enhanced exposure might allow better fracture reduction and evacuation of debris and hematoma from the maxillary sinus. The intraoral approach also avoids an external incision and scar, prevents such complications as pneumothorax or dural perforation, and reduces postoperative pain. In 60 cases of orbital and zygomatic complex fractures seen between 1985 and 1990, less than 8% required more extensive graft material than the maxillary antra could provide. To assess the potential advantages of local over extraanatomical bone grafts, we evaluated maxillary antral bone grafts obtained through buccal sulcus incisions in 14 patients for restoration following fractures of the orbit. Several of these patients are described. Bone union was complete in all patients and there was no morbidity related to infection, oroantral fistula formation, dehiscence, or disfigurement. Sufficient bone was available from the uninvolved contralateral side to repair even severely comminuted fractures. In zygomatic complex fractures, maxillary antral grafts appeared to provide additional strength in the region of the fractured maxillary buttress. The success of the procedure in our experience, coupled with the safety of bone harvesting from this source, and the avoidance of an external scar make maxillary antral bone well suited to reconstruction of all areas of the orbit.

  10. Surgical Management of Unusual Biangular Mandibular Fractures

    PubMed Central

    Autorino, Umberto

    2017-01-01

    Bilateral mandibular angle fractures, while representing a rarity among mandibular fractures, are a huge challenge of complex management for the maxillofacial surgeon. There are still many open questions regarding the ideal management of such fractures, including the following: the removal of the third molar in the fracture line, the best surgical approach, and the fixation methods. In this report the authors present the case of 40-year-old man presenting with a bilateral mandibular angle fracture referred to the Maxillofacial Surgery Department of Turin. Open reduction and internal fixation has been made for both sides. The left side third molar was removed and the internal fixation was achieved through internal fixation with one miniplate according to Champy's technique and transbuccal access for a 4-hole miniplate at the inferior border of the mandible. Right side third molar was not removed and fixation was achieved through intraoral access and positioning of a 4-hole miniplate along the external ridge according to Champy. An optimal reduction was achieved and a correct occlusion has been restored. PMID:28299228

  11. Geochemistry Model Validation Report: External Accumulation Model

    SciTech Connect

    K. Zarrabi

    2001-09-27

    The purpose of this Analysis and Modeling Report (AMR) is to validate the External Accumulation Model that predicts accumulation of fissile materials in fractures and lithophysae in the rock beneath a degrading waste package (WP) in the potential monitored geologic repository at Yucca Mountain. (Lithophysae are voids in the rock having concentric shells of finely crystalline alkali feldspar, quartz, and other materials that were formed due to entrapped gas that later escaped, DOE 1998, p. A-25.) The intended use of this model is to estimate the quantities of external accumulation of fissile material for use in external criticality risk assessments for different types of degrading WPs: U.S. Department of Energy (DOE) Spent Nuclear Fuel (SNF) codisposed with High Level Waste (HLW) glass, commercial SNF, and Immobilized Plutonium Ceramic (Pu-ceramic) codisposed with HLW glass. The scope of the model validation is to (1) describe the model and the parameters used to develop the model, (2) provide rationale for selection of the parameters by comparisons with measured values, and (3) demonstrate that the parameters chosen are the most conservative selection for external criticality risk calculations. To demonstrate the applicability of the model, a Pu-ceramic WP is used as an example. The model begins with a source term from separately documented EQ6 calculations; where the source term is defined as the composition versus time of the water flowing out of a breached waste package (WP). Next, PHREEQC, is used to simulate the transport and interaction of the source term with the resident water and fractured tuff below the repository. In these simulations the primary mechanism for accumulation is mixing of the high pH, actinide-laden source term with resident water; thus lowering the pH values sufficiently for fissile minerals to become insoluble and precipitate. In the final section of the model, the outputs from PHREEQC, are processed to produce mass of accumulation

  12. Metasurface external cavity laser

    SciTech Connect

    Xu, Luyao Curwen, Christopher A.; Williams, Benjamin S.; Hon, Philip W. C.; Itoh, Tatsuo; Chen, Qi-Sheng

    2015-11-30

    A vertical-external-cavity surface-emitting-laser is demonstrated in the terahertz range, which is based upon an amplifying metasurface reflector composed of a sub-wavelength array of antenna-coupled quantum-cascade sub-cavities. Lasing is possible when the metasurface reflector is placed into a low-loss external cavity such that the external cavity—not the sub-cavities—determines the beam properties. A near-Gaussian beam of 4.3° × 5.1° divergence is observed and an output power level >5 mW is achieved. The polarized response of the metasurface allows the use of a wire-grid polarizer as an output coupler that is continuously tunable.

  13. [Epidemiology of hip fracture].

    PubMed

    Hagino, Hiroshi

    2006-12-01

    Age- and gender-specific numbers of patients with hip fracture increase with age and peaked at the age 80-84; however, age- and gender-specific incidences increase exponentially with age. According to the recent nation-wide survey, the most common cause of hip fractures was a simple fall, 68.8% sustained fractures in-doors, and the incidences were higher in the winter than the summer period. More than 90% of patients with hip fracture were treated surgically and about 3/4 of patients with femoral neck fractures were treated with hemi-arthroplasty. Hip fractures for Asian people including Japanese are lower than those for Caucasians living in Northern Europe and North America; however, recent reports from the Asian area indicated an increase in the incidence with time.

  14. Dyslipidemia and sternum fracture.

    PubMed

    Can, Cagdas; Gulactı, Umut; Sarıhan, Aydin; Topacoglu, Hakan

    2013-06-01

    Tenderness over the sternum is a clue for possible sternal fracture. Sternal fractures usually occur at the body or manubrium. Lateral chest radiography could detect a sternum fracture, but the diagnosis is usually made by chest tomography. Traumatic sternum fracture considered as a marker of seriously life-threatening, high-energy injury. In hyperlipidemia, oxidized lipids accumulate in vascular tissues and trigger atherosclerosis. Such lipids also deposit in bone tissues where they may promote osteoporosis. In the literature, there is no previously reported traumatic sternal fracture due to hyperlipidemia-induced osteoporosis. Here, we report a case of a combined mixed type familial hyperlipidemia-induced osteoporosis in which the patient having seat belt on had an unexpected sternum fracture in a low-energy motor vehicle accident.

  15. Compilation of Physicochemical and Toxicological Information About Hydraulic Fracturing-Related Chemicals (Draft Database)

    EPA Science Inventory

    The purpose of this product is to make accessible the information about the 1,173 hydraulic fracturing-related chemicals that were listed in the external review draft of the Hydraulic Fracturing Drinking Water Assessment that was released recently. The product consists of a serie...

  16. [Nasal fractures in adults].

    PubMed

    Sjöstedt, Sannia; Larsen, Christian Grønhøj; Bilde, Anders; von Buchwald, Christian

    2016-03-07

    The risk of complications warrants treatment of most dislocated nasal fractures. Other injuries including other facial fractures and septal haematoma must be treated if present at the initial presentation. The usual treatment for a simple nasal fracture is closed reduction in local anaesthesia after five to seven days. Complicated cases require open reduction in general anaesthesia. Later revision of the deviated nose may become necessary in patients suffering from complications such as persistent nasal stenosis and/or deformity.

  17. Pediatric Hand Fractures

    PubMed Central

    Nellans, Kate W.; Chung, Kevin C.

    2014-01-01

    Summary Pediatric hand fractures are common childhood injuries. Identification of the fractures in the emergency room setting can be challenging owing to the physes and incomplete ossification of the carpus that are not revealed in the xrays. Most simple fractures can be treated with appropriate immobilization through buddy taping, finger splints, or casting. If correctly diagnosed, reduced and immobilized, these fractures usually result in excellent clinical outcomes. However, fractures may require operative stabilization if they have substantial angulation or rotation, extend into the joint, or cannot be held in a reduced position with splinting alone. Most fractures can be treated operatively with closed reduction and percutaneous pinning if addressed within the first week following the injury. In children, the thick, vascular-rich periosteum and bony remodeling potential make anatomic reductions and internal fixation rarely necessary. Most fractures complete bony healing in 3-4 weeks, with the scaphoid being a notable exception. Following immobilization, children rarely develop hand stiffness and formal occupational therapy is usually not necessary. Despite the high potential for excellent outcomes in pediatric hand fractures, some fractures remain difficult to diagnose and treat. PMID:24209954

  18. [Chondral and osteochondral fractures].

    PubMed

    Kayaoğlu, E Esin; Binnet, Mehmet S

    2007-01-01

    The incidence of traumatic chondral and osteochondral fractures and their role in the development of joint degeneration are not fully elucidated. While assessing traumatic knee injuries, one important criterion for the diagnosis of chondral fractures is to remember the possibility of a chondral or osteochondral fracture. Symptoms in osteochondral fractures are more obvious and cause severe pain and difficulty in movement of knee with hemarthrosis. The presence of hemarthrosis facilitates the diagnosis of an osteochondral fracture. Chondral and osteochondral fractures may be associated with other intra-articular pathologies. There are two main mechanisms of these fractures, including a direct effect causing avulsion or impaction and, a more common mechanism, flexion-rotation force to the knee, which is also the mechanism for an acute patellar dislocation. It is known that arthroscopic treatment is the best method for the diagnosis and treatment of chondral and osteochondral fractures. In osteochondral lesions, the aim of treatment is to restore the congruity of articular surfaces. In agreement with literature data, our clinical experience favors internal fixation as the most effective method for the treatment of osteochondral fractures.

  19. Natural fracture systems studies

    SciTech Connect

    Lorenz, J.C.; Warpinski, N.R.

    1992-09-01

    The objectives of this program are (1) to develop a basinal-analysis methodology for natural fracture exploration and exploitation, and (2) to determine the important characteristics of natural fracture systems for use in completion, stimulation, and production operations. Natural-fracture basinal analysis begins with studies of fractures in outcrop, core and logs in order to determine the type of fracturing and the relationship of the fractures to the lithologic environment. Of particular interest are the regional fracture systems that are pervasive in western US tight sand basins. A Methodology for applying this analysis is being developed, with the goal of providing a structure for rationally characterizing natural fracture systems basin-wide. Such basin-wide characterizations can then be expanded and supplemented locally, at sites where production may be favorable. Initial application of this analysis is to the Piceance basin where there is a wealth of data from the Multiwell Experiment (MWX), DOE cooperative wells, and other basin studies conducted by Sandia, CER Corporation, and the USGS (Lorenz and Finley, 1989, Lorenz et aI., 1989, and Spencer and Keighin, 1984). Such a basinal approach has been capable of explaining the fracture characteristics found throughout the southern part of the Piceance basin and along the Grand Hogback.

  20. Fracture detection logging tool

    DOEpatents

    Benzing, William M.

    1992-06-09

    A method and apparatus by which fractured rock formations are identified and their orientation may be determined includes two orthogonal motion sensors which are used in conjunction with a downhole orbital vibrator. The downhole vibrator includes a device for orienting the sensors. The output of the sensors is displayed as a lissajou figure. The shape of the figure changes when a subsurface fracture is encountered in the borehole. The apparatus and method identifies fractures rock formations and enables the azimuthal orientation of the fractures to be determined.

  1. SEGMENTAL CLAVICLE FRACTURE

    PubMed Central

    Grossi, Evander Azevedo

    2015-01-01

    The aim here was to present an unusual case of segmental clavicle fracture associated with ipsilateral rib fracture. Although the clavicle is very superficial, undetected cases of both types of fracture may occur, because these patients usually suffer multiple trauma. The case of a patient with a fracture of the diaphysis and lateral extremity of the clavicle is described: the patient was treated surgically and an excellent result was achieved. Similar cases in the literature are reviewed and their management is discussed. PMID:27047835

  2. [(Impending) pathological fracture].

    PubMed

    Sutter, P M; Regazzoni, P

    2002-01-01

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

  3. Working with External Evaluators

    ERIC Educational Resources Information Center

    Silver, Lauren; Burg, Scott

    2015-01-01

    Hiring an external evaluator is not right for every museum or every project. Evaluations are highly situational, grounded in specific times and places; each one is unique. The museum and the evaluator share equal responsibility in an evaluation's success, so it is worth investing time and effort to ensure that both are clear about the goals,…

  4. [Internal and external haemorrhoids].

    PubMed

    Schuurman, J P; Go, P M N Y H

    2011-01-01

    In this article, we present 3 cases of patients with different types of haemorrhoidal disease. The first patient is a 27-year-old woman who had been experiencing incidental rectal blood loss without pain during defecation for 3 months. The second patient is a 76-year-old woman who had been bothered by varying degrees of pain from a swelling nearby the anus for 1 year. The third case involves a 31-year-old man who had had continuous severe pain in the anal area for 3 consecutive days. The first patient appeared to have internal hemorrhoids, whereas different forms of external hemorrhoids affected the patients in the other 2 cases. Internal haemorrhoids develop from the intraluminal corpus cavernosum recti; external haemorrhoids from the perianal marginal veins. Patients with internal haemorrhoids present with symptoms that include blood loss and prolaps feeling during defecation. In patients with external haemorrhoids pain is the prominent symptom. Internal haemorrhoids are treated either conservatively or surgically, depending upon their severity. Considering external haemorrhoidal disease surgical treatment provides the most rapid and persistent relief of symptoms.

  5. External College Survey.

    ERIC Educational Resources Information Center

    Gold, Ben K.

    This report presents the results of a community survey which attempted to determine the demand for another college in the Los Angeles Community College District. The function of this "community campus" or "external college" would be to serve members of the community who are not already served by the eight existing colleges. Questionnaires received…

  6. External Interest Group Impingements.

    ERIC Educational Resources Information Center

    Millard, Richard M.

    The history of the interrelation among state approval, accreditation, and institutional eligibility is considered. It is suggested that faculty and college administrators can be either an internal or external group in relationship to the planning process. The federal government, or the state government, passes legislation that may have both…

  7. [Retroperitoneal hematoma in pelvic fractures].

    PubMed

    Purghel, F; Jemna, C; Ciuvică, R

    2011-01-01

    Retroperitoneal trauma implies a wide variety of organs in multiple systems (digestive, urinary, circulatory, musculoskeletal); although their common result is the retroperitoneal hematoma, their management is completely different, an intervention indicated for a particular lesion being able to completely decompensate other lesions in case of insufficient diagnostic. The present material highlights the recent diagnostic and therapeutic particularities in retroperitoneal hematoma from pelvic fractures. We noted a recent trend in diminishing the role of the fracture pattern on standard pelvis X-ray in assessing the risk of hemodinamic instability, new markers being indicated as more predictive. CT scan with contrast substance, when applies, remains the gold standard in identifying the source of the vascular bleeding and in guiding the subsequent therapeutic maneuvers. The angiographic embolisation in arterial lesions remains the main therapeutic procedure in hemodinamical unstable patients, with the possibility of repeating it when needed; the C-clamp external fixator application is associated. The pre-peritoneal packing constantly gains support as an emergency hemostasis maneuver. The treatment should be adapted in each case, the hemodinamic instability being the trigger in initiation and repetition of the emergency therapeutic interventions mentioned above.

  8. Analysis of zygomatic fractures.

    PubMed

    Hwang, Kun; Kim, Dong Hyun

    2011-07-01

    The purpose of this study was to evaluate the natural history of zygomatic fractures in 469 cases over 14 years. The medical records of patients seeking treatment for zygomatic fractures were reviewed. The zygomatic fractures were classified as monopod, dipod, or tripod fractures for most patients. The monopod fractures included (1) zygomaticofrontal, (2) zygomaticomaxillary, and (3) zygomatic arch fractures. The dipod fractures were subclassified into 3 types according to combination of the previously mentioned 3 sites, which were 1 and 2, 1 and 3, and 2 and 3. Tripod fracture included all 1, 2, and 3. Among 469 cases of zygomatic fractures, tripod fractures (n = 238, 50.7%), zygomaticomaxillary fracture (n = 121, 25.8%), and isolated fracture of the zygomatic arch (n = 98 20.9%) formed most of the cases (n = 457, 97.4%). About one-half cases were tripod fractures (n = 238, 50.7%), and another half cases were monopod fractures (n = 220, 46.9%). Only 11 cases (2.4%) were dipod fractures. Most of the monopod fractures were zygomaticomaxillary (n = 121, 25.8%) and zygomatic arch fractures (n = 98, 20.9%). Among the dipod fractures, no cases of zygomaticofrontal and zygomatic arch fractures were reported. An open reduction was performed in 73.8% (346 cases), closed reduction in 24.5% (115 cases), and conservative treatment in only 1.7%. In tripod fracture (n = 238), an open reduction and internal fixation was performed for most of the cases (n = 225, 94.5%), and closed reduction was performed in only 11 cases (4.6%). In monopod zygomaticomaxillary fracture (n = 121), internal fixation was performed for most of the cases (n = 108, 89.3%), and closed reduction was performed in only 9 cases (7.7%). However, in monopod fracture of the zygomatic arch (n = 98), most of the cases (n = 95, 96.9%) were treated with closed reduction; open reduction was performed in only 1 case (1.0%). At zygomaticofrontal area (n = 241), internal fixation was performed in most of the cases (n

  9. The Process of Hydraulic Fracturing

    EPA Pesticide Factsheets

    Hydraulic fracturing, know as fracking or hydrofracking, produces fractures in a rock formation by pumping fluids (water, proppant, and chemical additives) at high pressure down a wellbore. These fractures stimulate the flow of natural gas or oil.

  10. Compression fractures of the back

    MedlinePlus

    Vertebral compression fractures ... the most common cause of this type of fracture. Osteoporosis is a disease in which bones become ... the spine, such as multiple myeloma Having many fractures of the vertebrae can lead to kyphosis . This ...

  11. Hip Fractures among Older Adults

    MedlinePlus

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

  12. Prevention and management of external fixator pin track sepsis.

    PubMed

    Ferreira, Nando; Marais, Leonard Charles

    2012-08-01

    Pin track-associated complications are almost universal findings with the use of external fixation. These complications are catastrophic if it leads to the failure of the bone-pin interface and could lead to pin loosening, fracture non-union and chronic osteomyelitis. Strategies proposed for the prevention and management of pin track complications are diverse and constantly changing. Prevention of external fixation pin track infection is a complex and ongoing task that requires attention to detail, meticulous surgical technique and constant vigilance.

  13. [Fracture arthroplasty of femoral neck fractures].

    PubMed

    Braun, K F; Hanschen, M; Biberthaler, P

    2016-04-01

    A paradigm shift in the treatment of elderly patients has recently taken place leading to an increase in joint replacement surgery. The aim of this article is to highlight new developments and to present a treatment algorithm for femoral neck fractures. The age limit must be individually determined considering the comorbidities and perioperative risk profile. Pertrochanteric femoral fractures are nearly exclusively treated by osteosynthesis regardless of age. The situation for femoral neck fractures is more complex. Patients younger than 65 years should generally be treated by osteosynthesis but patients older than 65 years benefit from hemiarthroplasty or total hip arthroplasty. In patients aged between 65 and 75 years with high functional demands and a justifiable perioperative risk, total joint replacement is the treatment of choice. In physically less active patients older than 75 years and poor general condition, preference should be given to hemiarthroplasty.

  14. Avulsion fractures in athletes.

    PubMed Central

    Orava, S.; Ala-Ketola, L.

    1977-01-01

    34 cases of avulsion fractures are described. Each fracture took place during athletic training or competition. Excepting six sportsmen participating in a general fitness programme, every patient was an active competitive athlete. There were six women and 28 men; their average age was 20.1 years, raised by a few middle-aged "fitness sportsmen". Most avulsion fractures took place in sprinters and hurdlers; next were middle and long distance renner, footballers, fitness joggers, skiers and ice-hockey players. The most usual location of a fracture was the anterior pelvic spines; avulsion fractures were also detected in various parts of lower limbs. There were fewer avulsion fractures in the area of the trunk and upper extremities. Roetgenologically, the diagnosis of an avulsion fracture is generally easy to make. However, the diagnosis is facilitated by knowing the mechanism of the injury, the technique of the athletic event, and some of the training methods. Generally, a fracture heals well, even if it requires both sufficient immobilisation and some delay in resuming physical exertion. PMID:884433

  15. Fracture of glass

    NASA Technical Reports Server (NTRS)

    Henshaw, John M.

    1993-01-01

    The objectives of this educational exercise are the following: to observe and understand the fracture behavior of a brittle material; and to quantify the effects of various treatments on that material designed to modify its strength. A brief introduction to beam bending, fracture mechanics, influence of surface defects, residual stress, and static fatigue is presented. A test procedure for specimen testing is also presented.

  16. TIBIAL SHAFT FRACTURES

    PubMed Central

    Kojima, Kodi Edson; Ferreira, Ramon Venzon

    2015-01-01

    The long-bone fractures occur most frequently in the tibial shaft. Adequate treatment of such fractures avoids consolidation failure, skewed consolidation and reoperation. To classify these fractures, the AO/OTA classification method is still used, but it is worthwhile getting to know the Ellis classification method, which also includes assessment of soft-tissue injuries. There is often an association with compartmental syndrome, and early diagnosis can be achieved through evaluating clinical parameters and constant clinical monitoring. Once the diagnosis has been made, fasciotomy should be performed. It is always difficult to assess consolidation, but the RUST method may help in this. Radiography is assessed in two projections, and points are scored for the presence of the fracture line and a visible bone callus. Today, the dogma of six hours for cleaning the exposed fracture is under discussion. It is considered that an early start to intravenous antibiotic therapy and the lesion severity are very important. The question of early or late closure of the lesion in an exposed fracture has gone through several phases: sometimes early closure has been indicated and sometimes late closure. Currently, whenever possible, early closure of the lesion is recommended, since this diminishes the risk of infection. Milling of the canal when the intramedullary nail is introduced is still a controversial subject. Despite strong personal positions in favor of milling, studies have shown that there may be some advantage in relation to closed fractures, but not in exposed fractures. PMID:27026999

  17. TIBIAL SHAFT FRACTURES.

    PubMed

    Kojima, Kodi Edson; Ferreira, Ramon Venzon

    2011-01-01

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

  18. Temporary External Fixation is Safe In a Combat Environment

    DTIC Science & Technology

    2010-07-01

    fixation. Clin Orthop Relat Res. 1988;230:98–115. 23. Paley D. Problems, obstacles, and complications of limb lengthening by the Ilizarov technique...controlling hemorrhage, restoring limb perfusion, soft-tissue debride- ment, and achieving bony stability without disrupting resus- citation of the patient.24...B, Jovanovic S, Wertheimer B, Mikolasević I, Grdic P. External fixation as a primary and definitive treatment of open limb fractures. Injury

  19. Vertebroplasty for Spine Fracture Pain

    MedlinePlus

    ... Resources Drugs, Procedures & Devices Procedures & Devices Vertebroplasty for Spine Fracture Pain Vertebroplasty for Spine Fracture Pain Drugs, Procedures & DevicesProcedures & DevicesYour Health Resources ...

  20. Externally heated thermal battery

    NASA Astrophysics Data System (ADS)

    Pracchia, Louis; Vetter, Ronald F.; Rosenlof, Darwin

    1991-04-01

    A thermal battery activated by external heat comprising an anode (e.g., composed of a lithium-aluminum alloy), a cathode (e.g., composed of iron disulfide), and an electrolyte (e.g., a lithium chloride-potassium chloride eutectic) with the electrolyte inactive at ambient temperature but activated by melting at a predetermined temperature when exposed to external heating is presented. The battery can be used as a sensor or to ignite pyrotechnic and power electronic devices in a system for reducing the hazard of ordnance exposed to detrimental heating. A particular application is the use of the battery to activate a squib to function in conjunction with one or more other components to vent an ordnance case in order to prevent its explosion in a fire.

  1. Transphyseal Distal Humerus Fracture.

    PubMed

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

    2016-01-01

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

  2. Externally triggered microcapsules

    NASA Technical Reports Server (NTRS)

    Morrison, Dennis R. (Inventor); Mosier, Benjamin (Inventor)

    2011-01-01

    Disclosed are microcapsules comprising a polymer shell enclosing one or more immiscible liquid phases in which a drug or drug precursor are contained in a liquid phase. The microparticles also contain magnetic particles that can be heated by application of an external magnetic field and thus heated to a predetermined Curie temperature. Heating of the particles melts the polymer shell and releases the drug without causing heating of surrounding tissues.

  3. Particle Swarms in Fractures: Open Versus Partially Closed Systems

    NASA Astrophysics Data System (ADS)

    Boomsma, E.; Pyrak-Nolte, L. J.

    2014-12-01

    In the field, fractures may be isolated or connected to fluid reservoirs anywhere along the perimeter of a fracture. These boundaries affect fluid circulation, flow paths and communication with external reservoirs. The transport of drop like collections of colloidal-sized particles (particle swarms) in open and partially closed systems was studied. A uniform aperture synthetic fracture was constructed using two blocks (100 x 100 x 50 mm) of transparent acrylic placed parallel to each other. The fracture was fully submerged a tank filled with 100cSt silicone oil. Fracture apertures were varied from 5-80 mm. Partially closed systems were created by sealing the sides of the fracture with plastic film. The four boundary conditions study were: (Case 1) open, (Case 2) closed on the sides, (Case 3) closed on the bottom, and (Case 4) closed on both the sides and bottom of the fracture. A 15 μL dilute suspension of soda-lime glass particles in oil (2% by mass) were released into the fracture. Particle swarms were illuminated using a green (525 nm) LED array and imaged with a CCD camera. The presence of the additional boundaries modified the speed of the particle swarms (see figure). In Case 1, enhanced swarm transport was observed for a range of apertures, traveling faster than either very small or very large apertures. In Case 2, swarm velocities were enhanced over a larger range of fracture apertures than in any of the other cases. Case 3 shifted the enhanced transport regime to lower apertures and also reduced swarm speed when compared to Case 2. Finally, Case 4 eliminated the enhanced transport regime entirely. Communication between the fluid in the fracture and an external fluid reservoir resulted in enhanced swarm transport in Cases 1-3. The non-rigid nature of a swarm enables drag from the fracture walls to modify the swarm geometry. The particles composing a swarm reorganize in response to the fracture, elongating the swarm and maintaining its density. Unlike a

  4. Epidemiology of hip fractures.

    PubMed

    Kannus, P; Parkkari, J; Sievänen, H; Heinonen, A; Vuori, I; Järvinen, M

    1996-01-01

    There were an estimated 1.66 million hip fractures world-wide in 1990. According to the epidemiologic projections, this worldwide annual number will rise to 6.26 million by the year 2050. This rise will be in great part due to the huge increase in the elderly population of the world. However, the age-specific incidence rates of hip fractures have also increased during the recent decades and in many countries this rise has not leveled off. In the districts where this increase has either showed or leveled off, the change seems to especially concern women's cervical fractures. In men, the increase has continued unabated almost everywhere. Reasons for the age-specific increase are not known: increase in the age-adjusted incidence of falls of the elderly individuals with accompanying deterioration in the age-adjusted bone quality (strength, mineral density) may partially explain the phenomenon. The growth of the elderly population will be more marked in Asia, Latin America, the Middle East, and Africa than in Europe and North America, and it is in the former regions that the greatest increments in hip fracture are projected so that these regions will account for over 70% of the 6.26 million hip fractures in the year 2050. The incidence rates of hip fractures vary considerably from population to population and race to race but increase exponentially with age in every group. Highest incidences have been described in the whites of Northern Europe (Scandinavia) and North America. In Finland, for example, the 1991 incidence of hip fractures was 1.1% for women and 0.7% for men over 70 years of age. Among elderly nursing home residents, the figures can be as high as 6.2% and 4.9%. The lifetime risk of a hip fracture is 16%-18% in white women and 5%-6% in white men. At the age of 80 years, every fifth woman and at the age of 90 years almost every second woman has suffered a hip fracture. Since populations are aging worldwide, the mean age of the hip fracture patients are

  5. [Surgical treatment of humerus condylar fracture].

    PubMed

    Gorodnichenko, A I; Guseĭnov, T Sh; Uskov, O N

    2014-01-01

    55 patients with intra-articular condyles fractures of humerus were operated in terms 1998 to 2013 year in the Clinic of Traumatology and Orthopedics of the Presidential Administration. All patients were operated by using of perosseous osteosynthesis method with external fixing device design A.I. Gorodnichenko. Indications for osteosynthesis were open and closed fractures of C1,2,3 types accordingly to AO Classification. Closed, atraumatic and reliable fixation of bone fragments intensifies patients faster, improves their life quality, decreases time of hospitalization and minimizes complications rate. Fractures consolidation was achieved in all cases. It was observed such complications as soft tissue inflammatory around shafts in 4 (7.3%) observations. Long-term results were studied in 51 (92.7%) patients including 9 (17.6%) patients with excellent results, 24 (47.1%) patients with good results and 18 (35.3%) patients with satisfactory results. It was not detected unsatisfactory results. The method permits early reconstructive treatment of patients and improves functional results in case of condyles fractures. This preserves active moving function of damaged elbow from the first day after operation and during all period of treatment.

  6. Vallecular rupture with cervical spine fracture after a failed hanging suicide attempt.

    PubMed

    Kwon, Joong Keun; Lee, Seong Rok; Lee, Ho Min; Lee, Jung Min; Lee, Jong Cheol

    2013-09-01

    Hanging is a common method of suicide. We present a case of vallecular rupture and cervical spine fracture without an external wound after a failed hanging suicide attempt. Surgical treatment involved posterior fusion of C2 to 3, followed by repair of the vallecular rupture via an external approach. The patient recovered with no residual physical or mental sequelae.

  7. Treatment of Pediatric Open Supracondylar Humerus Fractures: Case Report

    PubMed Central

    Al-Sadek, Tabet A.; Niklev, Desislav; Al-Sadek, Ahmed

    2016-01-01

    BACKGROUND: Open supracondylar fractures of the humerus are rare in children, and the treatment strategy for these fractures is yet to be standardised. AIM: We present the case of a 7-year-old boy with open supracondylar humerus fracture that was managed with an external wrist fixator. CASE PRESENTATION: A 7-year-boy was brought to our department with pain in the right arm after a fall from a height about 3 hours before admission. On examination, the elbow was found to be markedly swollen with restriction of movement of the right arm. A 4-cm-wide wound was also observed on the flexural aspect of the elbow, indicating severe contamination of the fractured site. Neurological examination revealed restriction of hand movement and decreased sensations, which suggested the possibility of nerve injuries. CONCLUSION: A good clinical outcome was achieved in this case, without the development of any complications over a 6-month follow-up period. PMID:28028413

  8. Tibial fractures in children

    PubMed Central

    Palmu, Sauli A; Auro, Sampo; Lohman, Martina; Paukku, Reijo T; Peltonen, Jari I; Nietosvaara, Yrjänä

    2014-01-01

    Background Tibial fracture is the third most common long-bone fracture in children. Traditionally, most tibial fractures in children have been treated non-operatively, but there are no long-term results. Methods 94 children (64 boys) were treated for a tibial fracture in Aurora City Hospital during the period 1980–89 but 20 could not be included in the study. 58 of the remaining 74 patients returned a written questionnaire and 45 attended a follow-up examination at mean 27 (23–32) years after the fracture. Results 89 children had been treated by manipulation under anesthesia and cast-immobilization, 4 by skeletal traction, and 1 with pin fixation. 41 fractures had been re-manipulated. The mean length of hospital stay was 5 (1–26) days. Primary complications were recorded in 5 children. The childrens’ memories of treatment were positive in two-thirds of cases. The mean subjective VAS score (range 0–10) for function appearance was 9. Leg-length discrepancy (5–10 mm) was found clinically in 10 of 45 subjects and rotational deformities exceeding 20° in 4. None of the subjects walked with a limp. None had axial malalignment exceeding 10°. Osteoarthritis of the hip and/or knee was seen in radiographs from 2 subjects. Interpretation The long-term outcome of tibial fractures in children treated non-operatively is generally good. PMID:24786903

  9. Occult fractures of extremities.

    PubMed

    Ahn, Joong Mo; El-Khoury, Georges Y

    2007-05-01

    Recent advances in cross-sectional imaging, particularly in CT and MR imaging, have given these modalities a prominent role in the diagnosis of fractures of the extremities. This article describes the clinical application and imaging features of cross-sectional imaging (CT and MR imaging) in the evaluation of patients who have occult fractures of the extremities. Although CT or MR imaging is not typically required for evaluation of acute fractures, these modalities could be helpful in the evaluation of the occult osseous injuries in which radiographic findings are equivocal or inconclusive.

  10. Haemodynamically Unstable Pelvic Fractures

    DTIC Science & Technology

    2009-01-01

    patients with pelvic fractures. Ann Surg 2001;233:843–50. 12. Blackmore CC, Cummings P, Jurkovich GJ , et al. Predicting major hemorrhage in patients...with pelvic fracture. J Trauma 2006;61:346–52. 13. Blackmore CC, Jurkovich GJ , Linnau KF, et al. Assessment of volume of hemorrhage and outcome from...outcome of blunt trauma patients sustaining pelvic fractures. Injury 2000;31:677–82. 55. Haidukewych GJ , Kumar S, Prpa B. Placement of half-pins for

  11. External Ballistics. Part 1

    DTIC Science & Technology

    1978-07-11

    clcsely related with aezodyzasics, ky gzavtaetry and the thecry cf the figure of Earth , by metecrology. Ballistic calculatica Sives all the bamic data...external tallistics. %he conteaFcrary state of the sciemce of the action cf rcckets and artillery ste]l cf different t)pes is such, that many of the e...height. L- 14near distance ovX tOf surface of thq Earth . ol - crbital velocity. V-1 - escape velocity. 2v_ - range angle. S- eaight of projqctile. Q

  12. External split field generator

    DOEpatents

    Thundat, Thomas George [Knoxville, TN; Van Neste, Charles W [Kingston, TN; Vass, Arpad Alexander [Oak Ridge, TN

    2012-02-21

    A generator includes a coil disposed about a core. A first stationary magnetic field source may be disposed on a first end portion of the core and a second stationary magnetic field source may be disposed on a second end portion of core. The first and second stationary magnetic field sources apply a stationary magnetic field to the coil. An external magnetic field source may be disposed outside the coil to apply a moving magnetic field to the coil. Electrical energy is generated in response to an interaction between the coil, the moving magnetic field, and the stationary magnetic field.

  13. DIRBE External Calibrator (DEC)

    NASA Technical Reports Server (NTRS)

    Wyatt, Clair L.; Thurgood, V. Alan; Allred, Glenn D.

    1987-01-01

    Under NASA Contract No. NAS5-28185, the Center for Space Engineering at Utah State University has produced a calibration instrument for the Diffuse Infrared Background Experiment (DIRBE). DIRBE is one of the instruments aboard the Cosmic Background Experiment Observatory (COBE). The calibration instrument is referred to as the DEC (Dirbe External Calibrator). DEC produces a steerable, infrared beam of controlled spectral content and intensity and with selectable point source or diffuse source characteristics, that can be directed into the DIRBE to map fields and determine response characteristics. This report discusses the design of the DEC instrument, its operation and characteristics, and provides an analysis of the systems capabilities and performance.

  14. Clinical survey of fractured teeth.

    PubMed

    Gher, M E; Dunlap, R M; Anderson, M H; Kuhl, L V

    1987-02-01

    Through a standardized procedure using clinical examination, interviews, and dental history, this 2-year study documents 100 cases of tooth fracture in 98 patients. For comparison, pertinent information was also recorded for more than 2,000 teeth in a randomly selected sample population. Two chief types of fracture were found: incomplete crown-root fractures and root fractures associated with earlier endodontic therapy.

  15. Mechanical Coal-Face Fracturer

    NASA Technical Reports Server (NTRS)

    Collins, E. R., Jr.

    1984-01-01

    Radial points on proposed drill bit take advantage of natural fracture planes of coal. Radial fracture points retracted during drilling and impacted by piston to fracture coal once drilling halts. Group of bits attached to array of pneumatic drivers to fracture large areas of coal face.

  16. A trial of measuring the displacement of tibial fragments with pinless external fixator.

    PubMed

    Wu, Jian; Ye, Datian; Wang, Guangzhi; Ding, Haishu

    2005-01-01

    Currently, the mechanical performances of pinless external fixator are primarily evaluated for application to long bone fractures. A new method that detecting the relative displacement changes of the tibial fragments with the pinless external fixator by the three dimensional measurement system was introduced to evaluate the performance of the pinless external fixator. And such testing item was taken as the complement for the mechanical performances of the pinless external fixator. In this paper, a high precision optical 3D measurement system was used to detect the displacement change in the anterior and posterior fracture part of the tibial bones which was fixed by a clamp pattern pinless external fixator in open tibial fractures. Furthermore, the relative displacement change and relative angle rotation were analyzed after obtaining the trajectory of the markers which fixed on the tibial fragments, the results were used to evaluate the stability of the pinless external fixator, and taken as the reference for revising the design of the pinless external fixator as well.

  17. Swimming in external fields

    NASA Astrophysics Data System (ADS)

    Stark, Holger

    2016-11-01

    Microswimmers move autonomously but are subject to external fields, which influence their swimming path and their collective dynamics. With three concrete examples we illustrate swimming in external fields and explain the methodology to treat it. First, an active Brownian particle shows a conventional sedimentation profile in a gravitational field but with increased sedimentation length and some polar order along the vertical. Bottom-heavy swimmers are able to invert the sedimentation profile. Second, active Brownian particles interacting by hydrodynamic flow fields in a three-dimensional harmonic trap can spontaneously break the isotropic symmetry. They develop polar order, which one can describe by mean-field theory reminiscent to Weiss theory of ferromagnetism, and thereby pump fluid. Third, a single microswimmer shows interesting non-linear dynamics in Poiseuille flow including swinging and tumbling trajectories. For pushers, hydrodynamic interactions with bounding surfaces stabilize either straight swimming against the flow or tumbling close to the channel wall, while pushers always move on a swinging trajectory with a specific amplitude as limit cycle.

  18. [External pancreatic fistulas management].

    PubMed

    Stepan, E V; Ermolov, A S; Rogal', M L; Teterin, Yu S

    2017-01-01

    The main principles of treatment of external postoperative pancreatic fistulas are viewed in the article. Pancreatic trauma was the reason of pancreatic fistula in 38.7% of the cases, operations because of acute pancreatitis - in 25.8%, and pancreatic pseudocyst drainage - in 35.5%. 93 patients recovered after the treatment. Complex conservative treatment of EPF allowed to close fistulas in 74.2% of the patients with normal patency of the main pancreatic duct (MPD). The usage of octreotide 600-900 mcg daily for at least 5 days to decrease pancreatic secretion was an important part of the conservative treatment. Endoscopic papillotomy was performed in patients with major duodenal papilla obstruction and interruption of transporting of pancreatic secretion to duodenum. Stent of the main pancreatic duct was indicated in patients with extended pancreatic duct stenosis to normalize transport of pancreatic secretion to duodenum. Surgical formation of anastomosis between distal part of the main pancreatic duct and gastro-intestinal tract was carried out when it was impossible to fulfill endoscopic stenting of pancreatic duct either because of its interruption and diastasis between its ends, or in the cases of unsuccessful conservative treatment of external pancreatic fistula caused by drainage of pseudocyst.

  19. Geothermal Ultrasonic Fracture Imager

    SciTech Connect

    Patterson, Doug; Leggett, Jim

    2013-07-29

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

  20. Clavicle Fracture (Broken Collarbone)

    MedlinePlus

    ... risks and benefits of surgery for your clavicle fracture. There are risks associated with any surgery, including: • Infection • Bleeding • Pain • Blood clots in your leg • Damage to ...

  1. Calcaneal stress fractures.

    PubMed

    Weber, Jason M; Vidt, Louis G; Gehl, Richard S; Montgomery, Travis

    2005-01-01

    The majority of plantar heel pain is diagnosed as plantar fasciitis or heel spur syndrome. When historic or physical findings are unusual or when routine treatment proves ineffective, one should consider an atypical cause of heel pain. Stress fractures of the calcaneus are a frequently unrecognized source of heel pain. In some cases they can continue to go unrecognized because the symptoms of calcaneal stress fractures sometimes improves with treatments aimed at plantar fasciitis. Calcaneal stress fractures can occur in any population of adults and even children and are common among active people, such as athletes, sports enthusiasts, and military personnel. It is likely that the number of diagnosed calcaneal stress fractures will rise among practitioners with an increased recognition of their possibility.

  2. Vertebral Compression Fractures

    MedlinePlus

    ... OI: Information on Vertebral Compression Fractures 804 W. Diamond Ave., Ste. 210 Gaithersburg, MD 20878 (800) 981- ... osteogenesis imperfecta contact : Osteogenesis Imperfecta Foundation 804 W. Diamond Avenue, Suite 210, Gaithersburg, MD 20878 Tel: 800- ...

  3. Distinct frequency dependent effects of whole-body vibration on non-fractured bone and fracture healing in mice.

    PubMed

    Wehrle, Esther; Wehner, Tim; Heilmann, Aline; Bindl, Ronny; Claes, Lutz; Jakob, Franz; Amling, Michael; Ignatius, Anita

    2014-08-01

    Low-magnitude high-frequency vibration (LMHFV) provokes anabolic effects in non-fractured bone; however, in fracture healing, inconsistent results were reported and optimum vibration conditions remain unidentified. Here, we investigated frequency dependent effects of LMHFV on fracture healing. Twelve-week-old, female C57BL/6 mice received a femur osteotomy stabilized using an external fixator. The mice received whole-body vibrations (20 min/day) with 0.3g peak-to-peak acceleration and a frequency of either 35 or 45 Hz. After 10 and 21 days, the osteotomized femurs and intact bones (contra-lateral femurs, lumbar spine) were evaluated using bending-testing, µ-computed tomography, and histomorphometry. In non-fractured trabecular bone, vibration with 35 Hz significantly increased the relative amount of bone (+28%) and the trabecular number (+29%), whereas cortical bone was not influenced. LMHFV with 45 Hz failed to provoke anabolic effects in trabecular or cortical bone. Fracture healing was not significantly influenced by whole-body vibration with 35 Hz, whereas 45 Hz significantly reduced bone formation (-64%) and flexural rigidity (-34%) of the callus. Although the exact mechanisms remain open, our results suggest that small vibration setting changes could considerably influence LMHFV effects on bone formation in remodeling and repair, and even disrupt fracture healing, implicating caution when treating patients with impaired fracture healing.

  4. Modelling of Specimen Fracture

    DTIC Science & Technology

    2013-09-23

    improve and test the software for larger dynamic problems. The following future work is recommended. 1) Multiple LS - DYNA files – for large problems...continuation of a previous study involving the implementation of a micromechanical fracture model into the LS - DYNA user-defined subroutines. Two fracture...these parameters involved parsing the output data of the selected FE code, LS - DYNA , including element stresses, strain energies, and nodal coordinates

  5. Fracture and Fatigue

    DTIC Science & Technology

    1988-04-01

    fracture. The main additional categories of crack growth are elastic-plastic crack growth, fatigue crack growth, and crack growth as affected by...FRACTURE AND FATIGUE R. 0. RITCHIE W. W. GERBERICH J. H. UNDERWOOD DTIC AM ELECTE JUL 1 11988 APRIL 1988 FH US ARMY ARMAMENT RESEARCH, DEVELOPMENT AND...other authorized documents. N The use of trade name(s) and/or manufacturer (s) does not constitute an official indorsement or approval. DESTRUCTION NOTICE

  6. Relative permeability through fractures

    SciTech Connect

    Diomampo, Gracel, P.

    2001-08-01

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

  7. Interlaminar fracture of composites

    NASA Technical Reports Server (NTRS)

    Obrien, T. K.

    1984-01-01

    Fracture mechanics has been found to be a useful tool for understanding composite delamination. Analyses for calculating strain energy release rates associated with delamination growth have been developed. These analyses successfully characterized delamination onset and growth for particular sources of delamination. Low velocity impact has been found to be the most severe source of composite delamination. A variety of test methods for measuring interlaminar fracture toughness are being developed to identify new composite materials with enhanced delamination resistance.

  8. Asisstance Arthroscopy in Juvenile Tillaux Fractures

    PubMed Central

    Mañero, Luciano Martin; Arroquy, Damian; Barrios, Juan Manuel; Botta, Juan Martin; Caceres, Carlos Alberto

    2017-01-01

    Introduction: Juvenile Tillaux Fracture is an isolated fracture of the lateral portion of the distal tibial epiphysis, considered SALTER-HARRIS fracture type 3, wherein the fragment is moved by the anterolateral ligament anterior inferior tibiofibular. They occur at the beginning of the 2nd decade of life and are caused by a force external rotation. The pattern of injury is considered a result of the closing sequence of the distal tibial physis, which usually closes around 15 years of age in girls and 17 in boys, this process usually takes about 18 months, occurring first in the central area of the physis, extending medially and finally to side, being this epiphyseal portion which is open at the time of the vulnerable to fracture injury in this age group. The curriculum includes RX, and TAC, being more sensitive to detect fragments of 2 or more mm of travel, but may overestimate the true displacement. The non-displaced fracture can be treated with cast immobilization and displaced with closed reduction (plantar flexion external rotation in the pronated foot and direct pressure on the anterolateral epiphysis). An equal displacement or > 2 mm of the articular surface is indication of open reduction and percutaneous fixation, because it may increase the risk of osteoarthritis in the future. Objective: Presentation of a case Juvenile Tillaux Fractures with surgical resolution under arthroscopic assistance. Methods: Male patient 14 years old who suffered indirect trauma left ankle during practice sports (rugby) in September 2015, 48 hours of evolution. After performing X-rays and scans one left Salter Harris type III at the level of distal tibial epiphysis (Tillaux fracture) ankle fracture was diagnosed. It had a greater than 2 mm displacement. As a reduction treatment and percutaneous osteosynthesis with more osteodesis screw with arthroscopic assistance and fluoroscopy was performed. After surgery a long leg cast was placed for three weeks, continuing with three other

  9. Treatment of Thoracolumbar Fracture

    PubMed Central

    Kim, Byung-Guk; Shin, Dong-Eun

    2015-01-01

    The most common fractures of the spine are associated with the thoracolumbar junction. The goals of treatment of thoracolumbar fracture are leading to early mobilization and rehabilitation by restoring mechanical stability of fracture and inducing neurologic recovery, thereby enabling patients to return to the workplace. However, it is still debatable about the treatment methods. Neurologic injury should be identified by thorough physical examination for motor and sensory nerve system in order to determine the appropriate treatment. The mechanical stability of fracture also should be evaluated by plain radiographs and computed tomography. In some cases, magnetic resonance imaging is required to evaluate soft tissue injury involving neurologic structure or posterior ligament complex. Based on these physical examinations and imaging studies, fracture stability is evaluated and it is determined whether to use the conservative or operative treatment. The development of instruments have led to more interests on the operative treatment which saves mobile segments without fusion and on instrumentation through minimal invasive approach in recent years. It is still controversial for the use of these treatments because there have not been verified evidences yet. However, the morbidity of patients can be decreased and good clinical and radiologic outcomes can be achieved if the recent operative treatments are used carefully considering the fracture pattern and the injury severity. PMID:25705347

  10. FRACTURING FLUID CHARACTERIZATION FACILITY

    SciTech Connect

    Subhash Shah

    2000-08-01

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

  11. Subduction of fracture zones

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

  12. Prevention of hip fractures.

    PubMed

    Meunier, P J

    1993-11-30

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

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

    PubMed Central

    Ersozlu, S.; Aydinli, U.

    2006-01-01

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

  14. Bevalac external beamline optics

    SciTech Connect

    Kalnins, J.G.; Krebs, G.F.; Tekawa, M.M.; Alonso, J.R.

    1987-04-01

    This handbook is intended as an aid for tuning the external particle beam (EPB) lines at the Lawrence Berkeley Laboratory's Bevalac. The information contained within will be useful to the Bevalac's Main Control Room and experimenters alike. First, some general information is given concerning the EPB lines and beam optics. Next, each beam line is described in detail: schematics of the beam line components are shown, all the variables required to run a beam transport program are presented, beam envelopes are given with wire chamber pictures and magnet currents, focal points and magnifications. Some preliminary scaling factors are then presented which should aid in choosing a given EPB magnet's current for a given central Bevalac field. Finally, some tuning hints are suggested.

  15. External Measures of Cognition

    PubMed Central

    Cairό, Osvaldo

    2011-01-01

    The human brain is undoubtedly the most impressive, complex, and intricate organ that has evolved over time. It is also probably the least understood, and for that reason, the one that is currently attracting the most attention. In fact, the number of comparative analyses that focus on the evolution of brain size in Homo sapiens and other species has increased dramatically in recent years. In neuroscience, no other issue has generated so much interest and been the topic of so many heated debates as the difference in brain size between socially defined population groups, both its connotations and implications. For over a century, external measures of cognition have been related to intelligence. However, it is still unclear whether these measures actually correspond to cognitive abilities. In summary, this paper must be reviewed with this premise in mind. PMID:22065955

  16. Hanford External Dosimetry Program

    SciTech Connect

    Fix, J.J.

    1990-10-01

    This document describes the Hanford External Dosimetry Program as it is administered by Pacific Northwest Laboratory (PNL) in support of the US Department of Energy (DOE) and its Hanford contractors. Program services include administrating the Hanford personnel dosimeter processing program and ensuring that the related dosimeter data accurately reflect occupational dose received by Hanford personnel or visitors. Specific chapters of this report deal with the following subjects: personnel dosimetry organizations at Hanford and the associated DOE and contractor exposure guidelines; types, characteristics, and procurement of personnel dosimeters used at Hanford; personnel dosimeter identification, acceptance testing, accountability, and exchange; dosimeter processing and data recording practices; standard sources, calibration factors, and calibration processes (including algorithms) used for calibrating Hanford personnel dosimeters; system operating parameters required for assurance of dosimeter processing quality control; special dose evaluation methods applied for individuals under abnormal circumstances (i.e., lost results, etc.); and methods for evaluating personnel doses from nuclear accidents. 1 ref., 14 figs., 5 tabs.

  17. External Community Review Committee:

    PubMed Central

    Smith, Maureen A.; Kaufman, Nancy J.; Dearlove, Andrea J.

    2013-01-01

    Background: Major gaps exist between what we know and what we do in clinical practice and community health programs and narrowing this gap will require substantive partnerships between academic researchers and the communities they serve. Objectives: We describe a research pilot award program that makes a unique commitment to community engagement through the addition of an External Community Review Committee to the typical research review process that gives external stakeholders decision-making power over research funding. Methods: Whereas engaging community reviewers in discussion and rating of research proposals is not novel, the ICTR ECRC review process is distinct in that it is subsequent to peer review and uses different criteria and methodology. This method of engagement allows for the community review panel to re-rank scientifically meritorious proposals—such that proposals funded do not necessarily follow the rank order from scientific peer review. The approach taken by UW ICTR differs from those discussed in the literature that present a model of community-academic co-review. Results: This article provides guidance for others interested in this model of community engagement and reviews insights gained during the evolution of this strategy; including how we addressed conflict, how the committee was able to change the pilot award program over time, and individual roles that were crucial to the success of this approach. Conclusions: The advantages of this approach include success through traditional academic metrics while achieving an innovative shared-power mechanism for community engagement which we believe is critical for narrowing the gap between knowledge and practice. PMID:24056512

  18. Iatrogenic mandibular fracture associated with third molar removal after mandibular angle osteotectomy.

    PubMed

    Xu, Jia-Jie; Teng, Li; Jin, Xiao-Lei; Lu, Jian-Jian; Zhang, Chao

    2014-05-01

    The extraction of mandibular third molars is a common dental procedure. The complications include hemorrhage, pain, dental fracture, the displacement of teeth or fragments, iatrogenic damage or luxation of the second molar, neurologic injuries, soft tissue damage, subcutaneous emphysema, trismus, swelling, infection, and iatrogenic mandibular fracture. Fracture of the angle of the mandible associated with third molar removal is a rare but severe complication. This article describes a case of mandibular angle fracture associated with third molar extraction after mandibular angle osteotectomy, including a brief review of the literature. The removal of the mandibular angle and the outer cortex of the mandible, especially the external oblique ridge, may contribute to the bone fracture. We conclude that the extraction of the lower third molar must be before the removal of the mandibular angle, and a soft diet for at least 4 weeks postoperatively is essential to prevent late mandible fracture.

  19. Diagnosis, treatment, and rehabilitation of stress fractures in the lower extremity in runners

    PubMed Central

    Kahanov, Leamor; Eberman, Lindsey E; Games, Kenneth E; Wasik, Mitch

    2015-01-01

    Stress fractures account for between 1% and 20% of athletic injuries, with 80% of stress fractures in the lower extremity. Stress fractures of the lower extremity are common injuries among individuals who participate in endurance, high load-bearing activities such as running, military and aerobic exercise and therefore require practitioner expertise in diagnosis and management. Accurate diagnosis for stress fractures is dependent on the anatomical area. Anatomical regions such as the pelvis, sacrum, and metatarsals offer challenges due to difficulty differentiating pathologies with common symptoms. Special tests and treatment regimes, however, are similar among most stress fractures with resolution between 4 weeks to a year. The most difficult aspect of stress fracture treatment entails mitigating internal and external risk factors. Practitioners should address ongoing risk factors to minimize recurrence. PMID:25848327

  20. Bilateral Galeazzi fracture-dislocations: a case report of early rehabilitation.

    PubMed

    Komura, Shingo; Nonomura, Hidehiko; Satake, Takashi; Yokoi, Tatsuo

    2012-08-01

    A 24-year-old man had bilateral Galeazzi fracture-dislocations due to a motorcycle accident. The right radius fracture was a simple fracture and was fixed with a limited contact dynamic compression plate. The left radius fracture was a comminuted fracture and was fixed with a long locking compression plate in the bridging plate fashion while maintaining reduction with a temporary external fixator. Postoperative computed tomography under passive rotation of both forearms showed acceptable congruency of the distal radioulnar joints, and early rehabilitation of forearm rotation was started at 2 weeks after the operation. At 13-month follow-up, bone union of both fractures was achieved, and forearm motion was almost restored to normal. Moreover, no subluxation or dislocation of either distal radioulnar joint was observed.

  1. Macro- and Micro-Mechanics of Mixed-Mode Dynamic Fracture of Concrete. Part 1. Micro-Mechanic Analysis

    DTIC Science & Technology

    1993-02-14

    fracture energy density of concrete were discussed by Hillerborg and Mindess [55-57]. The total external energy needed to quasi-statically fracture a...Composites.: Strzin Rate Effects on Fracture, eds. S. Mindess and S.P Shah, Materials Research Society Symposia Proceeding Vol. 64, 1986 18 S. Mindess ...Nijhoff Publishers, 1985, pp. 617-636. I 1 9 A. Benton, S. Mindess , and N. Benthur, "The Behavior of Concrete Under Impact Loading: Experimental

  2. Imaging 3D strain field monitoring during hydraulic fracturing processes

    NASA Astrophysics Data System (ADS)

    Chen, Rongzhang; Zaghloul, Mohamed A. S.; Yan, Aidong; Li, Shuo; Lu, Guanyi; Ames, Brandon C.; Zolfaghari, Navid; Bunger, Andrew P.; Li, Ming-Jun; Chen, Kevin P.

    2016-05-01

    In this paper, we present a distributed fiber optic sensing scheme to study 3D strain fields inside concrete cubes during hydraulic fracturing process. Optical fibers embedded in concrete were used to monitor 3D strain field build-up with external hydraulic pressures. High spatial resolution strain fields were interrogated by the in-fiber Rayleigh backscattering with 1-cm spatial resolution using optical frequency domain reflectometry. The fiber optics sensor scheme presented in this paper provides scientists and engineers a unique laboratory tool to understand the hydraulic fracturing processes in various rock formations and its impacts to environments.

  3. Thrower's fracture of the humerus.

    PubMed

    Miller, Andrew; Dodson, Christopher C; Ilyas, Asif M

    2014-10-01

    Thrower's fractures are spiral fractures of the humerus caused by forceful throwing of a ball. Although these fractures have been cited in the literature, little research exists regarding the significance of stress fractures and fatigue injuries that may precede these injuries. This article presents 3 cases of middle-aged recreational baseball pitchers who sustained mid to distal third spiral humerus fractures, reviews the biomechanics of a thrower's fracture, and provides a detailed review of the literature to help better understand this condition and guide treatment.

  4. Frontal bone fractures.

    PubMed

    Marinheiro, Bruno Henrique; de Medeiros, Eduardo Henrique Pantosso; Sverzut, Cássio Edvard; Trivellato, Alexandre Elias

    2014-11-01

    The aim of this retrospective study was to evaluate the epidemiology, treatment, and complications of frontal bone fractures associated, or not, with other facial fractures. This evaluation also sought to minimize the influence of the surgeon's skills and the preference for any rigid internal fixation system. The files from 3758 patients who attended the Oral and Maxillofacial Surgery Department of the School of Dentistry of Ribeirao Preto, University of Sao Paulo, from March 2004 to November 2011 and presented with facial trauma were scanned, and 52 files were chosen for the review. Eleven (21.15%) of these patients had pure fractures of the frontal bone, and trauma incidence was more prevalent in men (92.3%), whites (61.53%), and adults (50%). Despite the use of helmets at the moment of the trauma, motorcycle crashes were the most common etiological factor (32.69%). Fracture of the anterior wall of the frontal sinus with displacement was the main injury observed (54.9%), and the most common treatment was internal fixation with a plate and screws (45.09%). Postoperative complications were observed in 35.29% of the cases. The therapy applied was effective in handling this type of fracture, and the success rate was comparable to that reported in other published studies.

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

    PubMed Central

    Burke, Neil G; Cosgrave, Ciaran H; O'Neill, Barry James; Kelly, Eamonn P

    2014-01-01

    Transstyloid, transscaphoid, transcapitate fractures are uncommon. We report the case of a 28-year-old man who sustained this fracture following direct trauma. The patient was successfully treated by open reduction internal fixation of the scaphoid and proximal capitate fragment, with a good clinical outcome at 1-year follow-up. This pattern is a new variant of scaphocapitate fracture as involves a fracture of the radial styloid as well. PMID:24686808

  6. Fracture mechanics expert system

    NASA Technical Reports Server (NTRS)

    Powers, E.; Elfer, N.; Casadaban, C.

    1992-01-01

    Attention is given to fracture mechanics, an analytical method used extensively in the National Space Transportation System to conservatively predict the remaining service life of an article when a flaw or a material defect is detected. These analyses are performed on hardware containing material defects that have been detected by various nondestructive inspection techniques. An expert system being developed to streamline the process so that hardware dispositions may be obtained in a timely and consistent manner is discussed. The expert system reduces the potential for errors due to the manual transcription between the various software programs involved in completing a fracture mechanics analysis. NEXPERT Object, the expert system development shell selected for this purpose, allows the various software programs used in fracture mechanics analyses to be accessed and manipulated from the same platform.

  7. Geometrically Frustrated Fracture Mechanics

    NASA Astrophysics Data System (ADS)

    Mitchell, Noah; Koning, Vinzenz; Vitelli, Vincenzo; Irvine, William T. M.

    2015-03-01

    When a flat elastic sheet is forced to conform to a surface with Gaussian curvature, stresses arise in the sheet. The mismatch between initial and final metrics gives rise to new fracture behavior which cannot be achieved by boundary loading alone. Using experiments of PDMS sheets frustrated on 3D-printed surfaces and a linearized analytical model, we demonstrate the ability of curvature to govern the sheets' fracture phenomenology. In this talk, we first show that curvature can both stimulate and suppress fracture initiation, depending on the position and orientation of the initial slit. Secondly, we show that curvature can steer the path of a crack as it propagates through the material. Lastly, the curvature can arrest cracks which would otherwise continue to propagate.

  8. DEM Particle Fracture Model

    SciTech Connect

    Zhang, Boning; Herbold, Eric B.; Homel, Michael A.; Regueiro, Richard A.

    2015-12-01

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

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

    PubMed

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

    2013-01-01

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

  10. Prevention and management of hip fracture in older patients.

    PubMed

    Swift, Cameron G

    2011-09-01

    The average age at hip fracture is 83 for women and 84 for men, with about 80% of cases in women. The 30% mortality and 20% new institutionalisation rates at 12 months reflect the high prevalence of comorbidity and to some extent suboptimal management at the time of the fracture. With timely intervention and better clinical management many fractures can be prevented and when they do occur their human and economic costs can be greatly reduced. Fragility fractures occur in those with demonstrable osteoporosis or osteopaenia and/or risk factors. The goal of prevention is to identify and treat those at risk UK clinicians lack a single universally endorsed, decision support resource. The prudent strategy is to become familiar with all three available risk measures, introduce fracture risk assessment into routine practice, and allow clinical judgement to prevail in cases of doubt (perhaps, especially in very elderly people, more often in the direction of intervention). The classical signs after a fall by an older person, of severe pain, shortening and external rotation of the affected limb, and loss of mobility, should result in immediate and rapid transfer to hospital. It is not rare in the case of intracapsular fractures for mobility to be deceptively maintained on a moderately or minimally painful hip.

  11. Oblique shear fractures of the lunate.

    PubMed

    Freeland, Alan E; Ahmad, Nawaiz

    2003-08-01

    Traumatic fractures of the lunate are rare. This article presents two patients who had displaced oblique lunate fractures and distal radius fractures. Both fractures achieved union; however, transient avascular necrosis occurred in the proximal healing of one patient.

  12. Fractures of the Thoracic and Lumbar Spine

    MedlinePlus

    .org Fractures of the Thoracic and Lumbar Spine Page ( 1 ) Spinal fractures can vary widely in severity. While some fractures are very serious injuries that require emergency treatment, other fractures can ...

  13. Externalities of oil imports revisited

    SciTech Connect

    Lemon, R.

    1980-09-01

    A re-analysis of the externalities associated with oil imports reaffirms the major findings of an earlier study: (1) The current externalities of oil imports are large even after several favorable assumptions are made, including the existence of a large buffer stock and enlightened monetary and fiscal policy. (2) The large externalities of oil imports call for increased domestic supplies, including conservation, if they are cost-effective and based on marginal social costs. (3) A corrective public policy could involve oil-import taxes and the subsidization of new domestic energy sources without large government externalities. 20 references.

  14. Unified tensile fracture criterion.

    PubMed

    Zhang, Z F; Eckert, J

    2005-03-11

    We find that the classical failure criteria, i.e., maximum normal stress criterion, Tresca criterion, Mohr-Coulomb criterion, and von Mises criterion, cannot satisfactorily explain the tensile fracture behavior of the bulk metallic glass (BMG) materials. For a better description, we propose an ellipse criterion as a new failure criterion to unify the four classical criteria above and apply it to exemplarily describe the tensile fracture behavior of BMGs as well as a variety of other materials. It is suggested that each of the classical failure criteria can be unified by the present ellipse criterion depending on the difference of the ratio alpha=tau(0)/sigma(0).

  15. Fractured Petroleum Reservoirs

    SciTech Connect

    Firoozabadi, Dr. Abbas

    2000-01-18

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

  16. Abraham Colles: Colles' fracture.

    PubMed

    Ellis, Harold

    2012-08-01

    Every reader of this journal will be all too familiar with Colles' fracture; either seeing patients with it in A & E, helping with its reduction and splinting or being part of the anaesthetics team involved in its management. On an icy winter's day there might be half a dozen patients with this injury in your accident unit, mostly elderly ladies. Yet it was not until 1814 that Abraham Colles accurately described this injury and its treatment in his paper 'On the fracture of the carpal extremity of the radius', published in the Edinburgh Medical and Surgical Journal of that year.

  17. Complications of mandibular fractures.

    PubMed

    Zweig, Barry E

    2009-03-01

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

  18. Optical modulation goes external

    NASA Astrophysics Data System (ADS)

    Loni, A.

    1995-02-01

    Digital or analog modulation of continuous-wave laser sources forms the basis of encoding and transmitting of information through optical fiber link systems. In digital systems, data are formatted in a simple periodic two-bit configuration, represented by high or low light intensities, whereas in analog systems data are represented by selective portions of a time-varying electronic waveform applied to the optical carrier. High speed optical communications and the distribution of cable television (CATV) signals are just two examples of digital and analog systems, respectively, that involve the transmission of data, voice and video over fiber networks. The basic layout of a fiber-optic link system is presented. The optical source wavelength is determined by the characteristics of the optical fiber. If the optical sources used is a semiconductor laser diode, information can be imprinted on the optical output by directly modulating the laser drive current with a radio frequency (RF) signal. In digital systems, the low (off) state generally corresponds to a position just below the lasing threshold on the characteristic intensity-current curve of the diode. This position is preferred to the zero current locus because the turn-on delays are then minimized. Analog systems require a bias current in addition to the threshold current in order to push the modulation into the linear region of the power-current curve. The main disadvantages associated with the direct modulation approach are discussed. The main disadvantage of the solid-state approach is its inability to modulate directly the laser at the data rates nominally entailed in optical communications. This inability causes further limitations associated with the inherently long excited state lifetime of the lasing species. External modulation overcomes this drawback by modulating the optical output from the laser rather than the material properties of the laser itself, and consequently, is set to play an increasingly

  19. Fracture After Total Hip Replacement

    MedlinePlus

    ... er Total Hip Replacement cont. • Dislocation • Limb length inequality • Poor fracture healing • Repeat fracture • Lack of in- ... Surgeons (AAOS). To learn more about your orthopaedic health, please visit orthoinfo.org. Page ( 5 ) AAOS does ...

  20. Preventing Falls and Related Fractures

    MedlinePlus

    ... increases your fracture risk. Catching yourself so you land on your hands or grabbing onto an object as you fall can prevent a hip fracture. Protective responses, such as reflexes and changes in posture that break the fall, can reduce ...

  1. Colles wrist fracture – aftercare

    MedlinePlus

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

  2. Progressive Fracture of Composite Structures

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.; Minnetyan, Levon

    2008-01-01

    A new approach is described for evaluating fracture in composite structures. This approach is independent of classical fracture mechanics parameters like fracture toughness. It relies on computational simulation and is programmed in a stand-alone integrated computer code. It is multiscale, multifunctional because it includes composite mechanics for the composite behavior and finite element analysis for predicting the structural response. It contains seven modules; layered composite mechanics (micro, macro, laminate), finite element, updating scheme, local fracture, global fracture, stress based failure modes, and fracture progression. The computer code is called CODSTRAN (Composite Durability Structural ANalysis). It is used in the present paper to evaluate the global fracture of four composite shell problems and one composite built-up structure. Results show that the composite shells and the built-up composite structure global fracture are enhanced when internal pressure is combined with shear loads.

  3. Scaphoid Fracture of the Wrist

    MedlinePlus

    .org Scaphoid Fracture of the Wrist Page ( 1 ) The scaphoid is one of the small bones in the wrist. It is ... that the scaphoid is injured. Cause A scaphoid fracture is usually caused by a fall on an ...

  4. Correlation of Hip Fracture with Other Fracture Types: Toward a Rational Composite Hip Fracture Endpoint

    PubMed Central

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

    2016-01-01

    Purpose With ethical requirements to the enrollment of lower risk subjects, osteoporosis trials are underpowered to detect reduction in hip fractures. Different skeletal sites have different levels of fracture risk and response to treatment. We sought to identify fracture sites which cluster with hip fracture at higher than expected frequency; if these sites respond to treatment similarly, then a composite fracture endpoint could provide a better estimate of hip fracture reduction. Methods Cohort study using Veterans Affairs and Medicare administrative data. Male Veterans (n=5,036,536) aged 50-99 years receiving VA primary care between1999-2009 were included. Fractures were ascertained using ICD9 and CPT codes and classified by skeletal site. Pearson correlation coefficients, logistic regression and kappa statistics, were used to describe the correlation between each fracture type and hip fracture within individuals, without regards to the timing of the events. Results 595,579 (11.8%) men suffered 1 or more fractures and 179,597 (3.6%) suffered 2 or more fractures during the time under study. Of those with one or more fractures, rib was the most common site (29%), followed by spine (22%), hip (21%) and femur (20%). The fracture types most highly correlated with hip fracture were pelvic/acetabular (Pearson correlation coefficient 0.25, p<0.0001), femur (0.15, p<0.0001), and shoulder (0.11, p<0.0001). Conclusions Pelvic, acetabular, femur, and shoulder fractures cluster with hip fractures within individuals at greater than expected frequency. If we observe similar treatment risk reductions within that cluster, subsequent trials could consider use of a composite endpoint to better estimate hip fracture risk. PMID:26151123

  5. Numerical Modeling of Fracture Propagation in Naturally Fractured Formations

    NASA Astrophysics Data System (ADS)

    Wang, W.; Prodanovic, M.; Olson, J. E.; Schultz, R.

    2015-12-01

    Hydraulic fracturing consists of injecting fluid at high pressure and high flowrate to the wellbore for the purpose of enhancing production by generating a complex fracture network. Both tensile failure and shear failure occur during the hydraulic fracturing treatment. The shear event can be caused by slip on existing weak planes such as faults or natural fractures. From core observation, partially cemented and fully cemented opening mode natural fractures, often with considerable thickness are widely present. Hydraulic fractures can propagate either within the natural fracture (tensile failure) or along the interface between the natural fracture and the rock matrix (tensile/shear failure), depending on the relative strength of cement and rock matrix materials, the bonding strength of interface, as well as the presence of any heterogeneities. In this study, we evaluate the fracture propagation both experimentally and numerically. We embed one or multiple inclusions of different mechanical properties within synthetic hydrostone samples in order to mimic cemented natural fractures and rock. A semi-circular bending test is performed for each set of properties. A finite element model built with ABAQUS is used to mimic the semi-circular bending test and study the fracture propagation path, as well as the matrix-inclusion bonding interface status. Mechanical properties required for the numerical model are measured experimentally. The results indicate that the match between experiment and modeling fracture path are extremely sensitive to the chosen interface (bonding) model and related parameters. The semi-circular bending test is dry and easily conducted, providing a good platform for validating numerical approaches. A validated numerical model will enable us to add pressurized fluid within the crack and simulate hydraulic fracture-natural fracture interaction in the reservoir conditions, ultimately providing insights into the extent of the fracture network.

  6. Penis Fracture: Is It Possible?

    MedlinePlus

    Healthy Lifestyle Sexual health Is it possible to fracture your penis? Answers from Landon Trost, M.D. Yes. Although rare, penis fracture ... Original article: http://www.mayoclinic.org/healthy-lifestyle/sexual-health/expert-answers/penis-fracture/faq-20058154 . Mayo Clinic ...

  7. Distal tibial derotational osteotomy with external fixation to treat torsional deformities: a review of 71 cases.

    PubMed

    Erschbamer, Matthias; Gerhard, Pascal; Klima, Harry; Ellenrieder, Birte; Zdenek-Lehnen, Katja; Giesinger, Karlmeinrad

    2017-03-01

    We retrospectively reviewed the safety and efficacy of operative treatment of torsional malalignment of the tibia in 44 children, on whom we performed 71 derotational osteotomies of the distal tibia to treat tibial torsion. We placed four pins using an alignment jig, performed a percutaneous osteotomy, and applied an external fixator after derotation. Postoperative radiographs showed accurate tibial derotation and pin placement in all patients. Nine patients developed superficial pin-tract infections that resolved with antibiotic treatment. Two developed fractures after removal of the external fixator, which healed in a plaster cast. Operative treatment of these cases with an external fixator is safe, effective, and well tolerated.

  8. Unstable Distal Radius Fractures Treated by Volar Locking Anatomical Plates

    PubMed Central

    Jose, Anto; Deniese, Pascal Noel; Babu, Abey Thomas; Rengasamy, Kanagasabai; Najimudeen, Syed

    2017-01-01

    Introduction Fracture of the distal end of radius represents the most common fracture of the upper extremity accounting for 16-20% of all fractures. Plating is now emerging as the gold standard for management of distal radius fractures due to increased rate of complications such as malunion, subluxation/dislocation of distal radio-ulnar joint or late collapse of fracture. Procedures such as closed reduction and cast immobilization, ligamentotaxis with external fixator and percutaneous pin fixation are no longer acceptable. Aim The purpose of the study was to evaluate the functional and radiological outcome of unstable distal radius fractures treated with the volar locking plate. Materials and Methods We reviewed 53 patients from January 2011 to December 2015, treated for unstable distal radius fractures using a volar locking compression plate. Standard radiographic and clinical assessment after 12 months (range 12-16 months) were measured and final functional and radiological outcome were assessed using the Modified Mayo wrist scoring system and Sarmiento’s modification of Lindstorm criteria respectively. Results There were 42 males and 11 females with an average age of 39.12±31.78 years (18-71 years). At the end of 12 months, 36 patients had an excellent radiological outcome and 10 patients had good radiological outcome as per Sarmiento’s modification of Lindstorm criteria. Eleven patients had an excellent functional outcome and 26 patients had a good functional outcome as per modified Mayo wrist scoring system. There was one case of superficial wound infection which subsided with intravenous antibiotics. Conclusion The volar locking plate fixation helps in early mobilization of the wrist, restores anatomy, allows early return to function, prevents secondary loss of reduction and hence is an effective treatment for unstable fractures of the distal radius. PMID:28274009

  9. External Examining: Fit for Purpose?

    ERIC Educational Resources Information Center

    Bloxham, Sue; Price, Margaret

    2015-01-01

    In a context of international concern about academic standards, the practice of external examining is widely admired for its role in defending standards. Yet a contradiction exists between this faith in examining and continuing concerns about standards. This article argues that external examining rests on assumptions about standards which are…

  10. Choosing a Truly External Evaluator

    ERIC Educational Resources Information Center

    Ray, Marilyn

    2006-01-01

    This scenario discusses a situation in which a proposal has been published by a consortium of foundations for an "external" evaluator to evaluate a replication at two new sites of a program they have been funding for many years. A proposal is received from Dr. Porto-Novo, who has been the external evaluator of the initial program for about 10…

  11. Tibia (Shinbone) Shaft Fractures

    MedlinePlus

    ... fractures in patients who are less healthy. • Early motion. Many doctors encourage leg motion early in the recovery period. For example, if ... will help you restore normal muscle strength, joint motion, and flexibility. AAOS does not endorse any treatments, ...

  12. Calcaneus (Heel Bone) Fractures

    MedlinePlus

    ... Calcaneus (Heel Bone) Fractures cont. Page ( 5 ) • Early motion. Many doctors encourage motion of the foot and ankle early in the ... therapy. Specific exercises can improve the range of motion in your foot and ankle, and strengthen supporting ...

  13. Infiltration into Fractured Bedrock

    SciTech Connect

    Salve, Rohit; Ghezzehei, Teamrat A.; Jones, Robert

    2007-09-01

    One potential consequence of global climate change and rapid changes in land use is an increased risk of flooding. Proper understanding of floodwater infiltration thus becomes a crucial component of our preparedness to meet the environmental challenges of projected climate change. In this paper, we present the results of a long-term infiltration experiment performed on fractured ash flow tuff. Water was released from a 3 x 4 m{sup 2} infiltration plot (divided into 12 square subplots) with a head of {approx}0.04 m, over a period of {approx}800 days. This experiment revealed peculiar infiltration patterns not amenable to current infiltration models, which were originally developed for infiltration into soils over a short duration. In particular, we observed that in part of the infiltration plot, the infiltration rate abruptly increased a few weeks into the infiltration tests. We suggest that these anomalies result from increases in fracture permeability during infiltration, which may be caused by swelling of clay fillings and/or erosion of infill debris. Interaction of the infiltration water with subsurface natural cavities (lithophysal cavities) could also contribute to such anomalies. This paper provides a conceptual model that partly describes the observed infiltration patterns in fractured rock and highlights some of the pitfalls associated with direct extension of soil infiltration models to fractured rock over a long period.

  14. Metatarsal fracture (acute) - aftercare

    MedlinePlus

    ... chap 88. Richter M, Kwon JY, DiGiovanni CW. Foot injuries. In: Browner BD, Jupiter JB, Krettek C, Anderson ... A.M. Editorial team. Related MedlinePlus Health Topics Foot Injuries and Disorders Fractures Browse the Encyclopedia A.D. ...

  15. Injection through fractures

    SciTech Connect

    Johns, R.A.

    1987-05-01

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

  16. Bipartite patella fracture.

    PubMed

    Canizares, George H; Selesnick, F Harlan

    2003-02-01

    Bipartite patella fracture is an uncommon injury that has rarely been described in the literature. It can be quite debilitating in the competitive athlete and is often overlooked by the treating physician. A bone scan can be helpful in confirming the diagnosis, and appropriate treatment often results in a successful outcome.

  17. Malignant external otitis: CT evaluation

    SciTech Connect

    Curtin, H.D.; Wolfe, P.; May, M.

    1982-11-01

    Malignant external otitis is an aggressive infection caused by Pseudomonas aeruginosa that most often occurs in elderly diabetics. Malignant external otitis often spreads inferiorly from the external canal to involve the subtemporal area and progresses medially towards the petrous apex leading to multiple cranial nerve palsies. The computed tomographic (CT) findings in malignant external otitis include obliteration of the normal fat planes in the subtemporal area as well as patchy destruction of the bony cortex of the mastoid. The point of exit of the various cranial nerves can be identified on CT scans, and the extent of the inflammatory mass correlates well with the clinical findings. Four cases of malignant external otitis are presented. In each case CT provided a good demonstration of involvement of the soft tissues at the base of the skull.

  18. Enhanced External Counterpulsation (EECP)

    PubMed Central

    2006-01-01

    class I; 35% are in class II; 25%, class III; and 5%, class IV. Surveys (8) suggest that from 5% to 15% of patients with HF have persistent severe symptoms, and that the remainder of patients with HF is evenly divided between those with mild and moderately severe symptoms. To date, the diagnosis and management of chronic HF has concentrated on patients with the clinical syndrome of HF accompanied by severe left ventricular systolic dysfunction. Major changes in treatment have resulted from a better understanding of the pathophysiology of HF and the results of large clinical trials. Treatment for chronic HF includes lifestyle management, drugs, cardiac surgery, or implantable pacemakers and defibrillators. Despite pharmacologic advances, which include diuretics, angiotensin-converting enzyme inhibitors, beta-blockers, spironolactone, and digoxin, many patients remain symptomatic on maximally tolerated doses. (6) The Technology Patients are typically treated by a trained technician in a medically supervised environment for 1 hour daily for a total of 35 hours over 7 weeks. The procedure involves sequential inflation and deflation of compressible cuffs wrapped around the patient’s calves, lower thighs and upper thighs. In addition to 3 sets of cuffs, the patient has finger plethysmogram and electrocardiogram (ECG) attachments that are connected to a control and display console. External counterpulsation was used in the United States to treat cardiogenic shock after acute myocardial infarction. (9;10) More recently, an enhanced version namely “enhanced external counterpulsation” (EECP) was introduced as a noninvasive procedure for outpatient treatment of patients with severe, uncontrollable cardiac ischemia. EECP is said to increase coronary perfusion pressure and reduce the myocardial oxygen demand. Currently, EECP is not applicable for all patients with refractory angina pectoris. For example, many patients are considered ineligible for therapy due to co

  19. Entablature: fracture types and mechanisms

    NASA Astrophysics Data System (ADS)

    Forbes, A. E. S.; Blake, S.; Tuffen, H.

    2014-05-01

    Entablature is the term used to describe zones or tiers of irregular jointing in basaltic lava flows. It is thought to form when water from rivers dammed by the lava inundates the lava flow surface, and during lava-meltwater interaction in subglacial settings. A number of different fracture types are described in entablature outcrops from the Búrfell lava and older lava flows in Þjórsárdalur, southwest Iceland. These are: striae-bearing, column-bounding fractures and pseudopillow fracture systems that themselves consist of two different fracture types—master fractures with dimpled surface textures and subsidiary fractures with curved striae. The interaction of pseudopillow fracture systems and columnar jointing in the entablature produces the chevron fracture patterns that are commonly observed in entablature. Cube-jointing is a more densely fractured version of entablature, which likely forms when more coolant enters the hot lava. The entablature tiers display closely spaced striae and dendritic crystal shapes which indicate rapid cooling. Master fracture surfaces show a thin band with an evolved composition at the fracture surface; mineral textures in this band also show evidence of quenching of this material. This is interpreted as gas-driven filter pressing of late-stage residual melt that is drawn into an area of low pressure immediately preceding or during master fracture formation by ductile extensional fracture of hot, partially crystallised lava. This melt is then quenched by an influx of water and/or steam when the master fracture fully opens. Our findings suggest that master fractures are the main conduit for coolant entering the lava flow during entablature formation.

  20. Phalangeal fractures: displaced/nondisplaced.

    PubMed

    Gaston, R Glenn; Chadderdon, Christopher

    2012-08-01

    Nonsurgical management is the preferred treatment of stable, extra-articular fractures of the proximal and middle phalanx, most distal phalanx fractures, and, rarely, nondisplaced intraarticular fractures in elite athletes. Techniques that afford maximal strength with minimal dissection, thus allowing earlier return to play, are ideal. Open reduction with internal fixation with plate fixation is most often chosen for unstable phalangeal shaft fractures in high-demand athletes to provide rigid internal fixation and allow immediate range of motion and more rapid return to sport. It is our practice to routinely treat unicondylar fractures with surgery with percutaneous headless compression screws in elite athletes.

  1. Linear elastic fracture mechanics primer

    NASA Technical Reports Server (NTRS)

    Wilson, Christopher D.

    1992-01-01

    This primer is intended to remove the blackbox perception of fracture mechanics computer software by structural engineers. The fundamental concepts of linear elastic fracture mechanics are presented with emphasis on the practical application of fracture mechanics to real problems. Numerous rules of thumb are provided. Recommended texts for additional reading, and a discussion of the significance of fracture mechanics in structural design are given. Griffith's criterion for crack extension, Irwin's elastic stress field near the crack tip, and the influence of small-scale plasticity are discussed. Common stress intensities factor solutions and methods for determining them are included. Fracture toughness and subcritical crack growth are discussed. The application of fracture mechanics to damage tolerance and fracture control is discussed. Several example problems and a practice set of problems are given.

  2. Antimicrobial Efficacy of External Fixator Pins Coated with a Lipid Stabilized Hydroxyapatite/Chlorhexidine Complex to Prevent Pin Tract Infection in a Goat Model

    DTIC Science & Technology

    2001-06-01

    Infection after intramedullary nailing of severe open tibial fractures initially treated with external fixation. J Bone Joint Surg Am. 1989;71:835–838. 4...McGraw JM, Lim EVA. Treatment of open tibial -shaft fractures, external fixation and secondary intramedullary nailing . J Bone Joint Surg Am. 1988;70:900... intramedullary nailing of open fractures of the tibial shaft. J Bone Joint Surg Am. 1990;72:729–735. 7. Antich-Adrover P, Marti-Garin D, Murias-Alvarez J

  3. Has Clinton made externalities extraneous

    SciTech Connect

    Haites, E.

    1993-08-01

    Over the past several years state utility regulators have become increasingly concerned with the environmental externalities associated with electricity generation. Currently, 26 states have requirements in place, although these vary considerably in scope and complexity. The vast majority apply only to the selection of new resources; the most detailed specify a monetary value for each discharge to the environment. Regulatory concern with environmental externalities stems from the desire to minimize the cost of electricity service to society. Externalities requirements focus on the residual discharges after environmental regulations are complied with. Ignoring externalities leads to inefficient use of resources and environmental damage beyond with may be called a [open quotes]socially optimal[close quotes] level of pollution. Adjusting to the cost options for environmental externalities should lead utilities to select a combination of resources that is closer to the socially optimal mix. President Bill Clinton's recent announcement that the United States will limit its emissions of carbon dioxide (CO[sub 2]) to 1990 levels by 2000 may make externalities regulation superfluous. National limits on sulfur dioxide (SO[sub 2]), nitrogen oxide (NO[sub x]), and CO[sub 2] emissions by utilities will likely be in effect by 2000. It will not be possible to comply with emissions limits solely through changes to the mix of resource additions, even though consideration of environmental externalities in resource addition decisions can reduce incremental emissions. Other strategies to reduce the emissions of existing generating stations, as well as new sources, will be needed.

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

    NASA Astrophysics Data System (ADS)

    Zhou, Jing

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

  5. Structural Continuum Modeling of Space Shuttle External Tank Foam Insulation

    NASA Technical Reports Server (NTRS)

    Steeve, Brian; Ayala, Sam; Purlee, T. Eric; Shaw, Phillip

    2006-01-01

    The Space Shuttle External Tank is covered with rigid polymeric closed-cell foam insulation to prevent ice formation, protect the metallic tank from aerodynamic heating, and control the breakup of the tank during re-entry. The cryogenic state of the tank, as well as the ascent into a vacuum environment, places this foam under significant stress. Because the loss of the foam during ascent poses a critical risk to the shuttle orbiter, there is much interest in understanding the stress state in the foam insulation and how it may contribute to fracture and debris loss. Several foam applications on the external tank have been analyzed using finite element methods. This presentation describes the approach used to model the foam material behavior and compares analytical results to experiments.

  6. A PTH-responsive circadian clock operates in ex vivo mouse femur fracture healing site.

    PubMed

    Kunimoto, Tatsuya; Okubo, Naoki; Minami, Yoichi; Fujiwara, Hiroyoshi; Hosokawa, Toshihiro; Asada, Maki; Oda, Ryo; Kubo, Toshikazu; Yagita, Kazuhiro

    2016-02-29

    The circadian clock contains clock genes including Bmal1 and Period2, and it maintains an interval rhythm of approximately 24 hours (the circadian rhythm) in various organs including growth plate and articular cartilage. As endochondral ossification is involved not only in growth plate but also in fracture healing, we investigated the circadian clock functions in fracture sites undergoing healing. Our fracture models using external fixation involved femurs of Period2::Luciferase knock-in mice which enables the monitoring of endogenous circadian clock state via bioluminescence. Organ culture was performed by collecting femurs, and fracture sites were observed using bioluminescence imaging systems. Clear bioluminescence rhythms of 24-hour intervals were revealed in fracture healing sites. When parathyroid hormone (PTH) was administered to fractured femurs in organ culture, peak time of Period2::Luciferase activity in fracture sites and growth plates changed, indicating that PTH-responsive circadian clock functions in the mouse femur fracture healing site. While PTH is widely used in treating osteoporosis, many studies have reported that it contributes to improvement of fracture healing. Future studies of the role of this local clock in wound healing may reveal a novel function of the circadian timing mechanism in skeletal cells.

  7. Fracture mechanics validity limits

    NASA Technical Reports Server (NTRS)

    Lambert, Dennis M.; Ernst, Hugo A.

    1994-01-01

    Fracture behavior is characteristics of a dramatic loss of strength compared to elastic deformation behavior. Fracture parameters have been developed and exhibit a range within which each is valid for predicting growth. Each is limited by the assumptions made in its development: all are defined within a specific context. For example, the stress intensity parameters, K, and the crack driving force, G, are derived using an assumption of linear elasticity. To use K or G, the zone of plasticity must be small as compared to the physical dimensions of the object being loaded. This insures an elastic response, and in this context, K and G will work well. Rice's J-integral has been used beyond the limits imposed on K and G. J requires an assumption of nonlinear elasticity, which is not characteristic of real material behavior, but is thought to be a reasonable approximation if unloading is kept to a minimum. As well, the constraint cannot change dramatically (typically, the crack extension is limited to ten-percent of the initial remaining ligament length). Rice, et al investigated the properties required of J-type parameters, J(sub x), and showed that the time rate, dJ(sub x)/dt, must not be a function of the crack extension rate, da/dt. Ernst devised the modified-J parameter, J(sub M), that meets this criterion. J(sub M) correlates fracture data to much higher crack growth than does J. Ultimately, a limit of the validity of J(sub M) is anticipated, and this has been estimated to be at a crack extension of about 40-percent of the initial remaining ligament length. None of the various parameters can be expected to describe fracture in an environment of gross plasticity, in which case the process is better described by deformation parameters, e.g., stress and strain. In the current study, various schemes to identify the onset of the plasticity-dominated behavior, i.e., the end of fracture mechanics validity, are presented. Each validity limit parameter is developed in

  8. Spinous process fractures in osteoporotic thoracolumbar vertebral fractures

    PubMed Central

    Seo, M R N; Park, S Y; Park, J S; Jin, W; Ryu, K N

    2011-01-01

    Objectives To evaluate the incidence and pattern of spinous process fractures (SPFs) in patients with osteoporotic compression fractures (OCFs) of the thoracolumbar spine. Methods Spinal MRI or CT of 398 female patients (age range 50–89 years, mean age 70 years) who had OCFs in the thoracolumbar spine were retrospectively reviewed. The incidence, location and imaging results for the SPFs were evaluated. Results Of the 398 patients who had thoracolumbar OCFs, 14 (3.5%) had SPF. In six patients with single compression fractures, the SPF occurred at the level just above the vertebral compression fracture. In six out of seven patients with multiple continuous compression fractures, the SPF occurred just one level above the uppermost level of the compression fracture. The remaining one patient who had thoracolumbar spinal fixation at T12–L2 with continuous compression fractures in T12–L5 had a SPF in L2. In one patient who had multiple compression fractures in discontinuous levels (fractures at T10 and L1, respectively), the SPF occurred at T12. The directions of the fractures were vertical or oblique vertical (perpendicular to the long axis of the spinous process) in all cases. Conclusion In the presence of an OCF in the thoracolumbar spine, a SPF was found in 3.5% of cases, and most of the fractures were located just one level above the compression fracture. Therefore, in patients who have OCF, the possibility of a SPF in the level just above the compression fracture should be considered. PMID:21343317

  9. MECHANICAL STUDY ON DORSAL STABILITY OF INTRAMEDULLARY OSTEOSYNTHESIS ASSOCIATED WITH EXTERNAL FIXATION (ULSON'S METHOD)

    PubMed Central

    Sardenberg, Trajano; Muller, Sérgio Swain; Medeiros, Daniel Ricardo; Baptistão, Pablo Luiz

    2015-01-01

    Objective: To evaluate the Ulson intramedullary fixation method, with external fixation in which the level of the external locking of the Kirschner wires is varied, and without external fixation. Methods: Eighteen porcine tibias were used. Transverse osteotomy was performed in the region of the tuberosity, and two intramedullary Kirschner wires were inserted into each specimen, using three different assembly patterns: Group I: locking with external minifixator at a height of 3.0 cm; Group II: locking at a height of 4.5 cm; Group III: without external locking. Mechanical shear tests were then conducted, to determine the maximum load, proportionality limit and coefficient of rigidity. Results: There were no significant differences in maximum load or proportionality limit between the groups. The coefficient of rigidity was higher in Group II. Conclusion: The locking height for the Kirschner wires in Ulson's method, within the limits evaluated, did not harm the stability of the fracture fixation system. PMID:27027069

  10. [Blind nailing of trochanteric fractures using the Ender method (author's transl)].

    PubMed

    Carret, J P; Van Cuyck, A; Bejui, J; Dejour, H; de Mourgues, G; Fischer, L P

    1980-01-01

    After trochanteric fractures, the rate of survival of old patients was best when treated by the Ender method: 15% died during 3 months following the fracture. The procedure is uneasy and an excellent radiologic technique is necessary. The position of the proximal end of the first nail in the femoral head is most important. Excessive external rotation was frequent, but little desabling. Secondary displacement of the nails toward the distal end occurred in 25% of the cases and was difficult to avoid but remained moderate. The procedure is indicated in old people with porotic bones. It should not be done in subtrochanteric fractures.

  11. Tillaux fracture of the ankle in an adult: a rare injury.

    PubMed

    Kumar, Narinder; Prasad, Manish

    2014-01-01

    The Tillaux fracture of the ankle is an external rotation ankle injury resulting in an avulsion fracture of the anterolateral tibial plafond. This injury is known to occur in adolescents, although it has rarely been reported in adults. We report a case of a Tillaux fracture in an adult. A brief description of the history, mechanism of injury, required imaging, and treatment and other management options are provided in the present report. Anatomic reduction, rigid fixation, and early mobilization are emphasized to obtain a satisfactory functional outcome, shown by the long-term follow-up findings.

  12. Primary ankle arthrodesis for neglected open Weber B ankle fracture dislocation.

    PubMed

    Thomason, Katherine; Ramesh, Ashwanth; McGoldrick, Niall; Cove, Richard; Walsh, James C; Stephens, Michael M

    2014-01-01

    Primary ankle arthrodesis used to treat a neglected open ankle fracture dislocation is a unique decision. A 63-year-old man presented to the emergency department with a 5-day-old open fracture dislocation of his right ankle. After thorough soft tissue debridement, primary arthrodesis of the tibiotalar joint was performed using initial Kirschner wire fixation and an external fixator. Definitive soft tissue coverage was later achieved using a latissimus dorsi free flap. The fusion was consolidated to salvage the limb from amputation. The use of primary arthrodesis to treat a compound ankle fracture dislocation has not been previously described.

  13. Fifth metatarsal fractures and current treatment

    PubMed Central

    Bowes, Julia; Buckley, Richard

    2016-01-01

    Metatarsal fractures are one of the most common injuries of the foot. There has been conflicting literature on management of fifth metatarsal fractures due to inconsistency with respect to classification of these fractures. This article provides a thorough review of fifth metatarsal fractures with examination of relevant literature to describe the management of fifth metatarsal fractures especially the proximal fracture. A description of nonoperative and operative management for fifth metatarsal fractures according to anatomical region is provided. PMID:28032031

  14. Wrist deformities after fracture.

    PubMed

    Vanheest, Ann

    2006-02-01

    Wrist deformities can occur after fracture because of malunion of the fracture or injury to the growth plate leading to imbalance of growth. Prevention of malunion is paramount by early recognition with proper reduction and casting or fixation with casting. If a mal-union occurs, an osteotomy may be necessary if anticipated growth will not correct the deformity. Injury of the growth plate may lead to wrist deformity in two ways: angular growth or growth arrest. Angular growth deformities are corrected most commonly by osteotomy. Growth arrest of the radius or the ulna leads to an ulnar-positive or an ulnar-negative variance at the wrist. If the ulnar variance is symptomatic, treatment is centered on achieving a level joint. Options for joint leveling procedures include epiphysiodesis or physeal stapling of the longer bone, lengthening osteotomy of the shorter bone, or shortening osteotomy of the longer bone.

  15. Characteristics of unilateral tibial plateau fractures among adult patients hospitalized at an orthopaedic trauma centre in China

    PubMed Central

    Liu, Yong; Liao, Zhengwen; Shang, Lei; Huang, Wenhua; Zhang, Dawei; Pei, Guoxian

    2017-01-01

    The aim of this study was to investigate the characteristics of unilateral tibial plateau fractures among hospitalized adult patients in Xijing Hospital, to evaluate the accuracy of Schatzker classification system and AO/OTA classification system to tibial plateau fractures. We retrospectively analysed clinical data on 274 patients admitted to Xijing Hospital between September 2006 and August 2015. The patients’ demographic characteristics, admission periods and seasons, external causes and fracture types were recorded and summarized. Then the characteristics of tibial plateau fractures and the accuracy rate of these two classification systems were analysed. Schatzker type II fractures and AO/OTA type 41-B3 fractures were the most common types. The external causes differed between genders, types of employment, urban-rural residents and both two systems. In addition, some fractures were difficult to classify using Schatzker or AO/OTA classification system. Rural male physical labourers aged between 30–59 years-old were most likely to suffer from unilateral tibial plateau fractures, due to traffic accidents, falls and indoor activity injuries, or falls from height. We should pay more attention to the related people and professions, which contributed to the high occurrence of tibial plateau fractures. Besides that, further improvements are required for both Schatzker and AO/OTA classification systems. PMID:28074894

  16. Melt fracture revisited

    SciTech Connect

    Greenberg, J. M.

    2003-07-16

    In a previous paper the author and Demay advanced a model to explain the melt fracture instability observed when molten linear polymer melts are extruded in a capillary rheometer operating under the controlled condition that the inlet flow rate was held constant. The model postulated that the melts were a slightly compressible viscous fluid and allowed for slipping of the melt at the wall. The novel feature of that model was the use of an empirical switch law which governed the amount of wall slip. The model successfully accounted for the oscillatory behavior of the exit flow rate, typically referred to as the melt fracture instability, but did not simultaneously yield the fine scale spatial oscillations in the melt typically referred to as shark skin. In this note a new model is advanced which simultaneously explains the melt fracture instability and shark skin phenomena. The model postulates that the polymer is a slightly compressible linearly viscous fluid but assumes no slip boundary conditions at the capillary wall. In simple shear the shear stress {tau}and strain rate d are assumed to be related by d = F{tau} where F ranges between F{sub 2} and F{sub 1} > F{sub 2}. A strain rate dependent yield function is introduced and this function governs whether F evolves towards F{sub 2} or F{sub 1}. This model accounts for the empirical observation that at high shears polymers align and slide more easily than at low shears and explains both the melt fracture and shark skin phenomena.

  17. Relative Dating Via Fractures

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    This VIS image of the eastern part of the Tharsis region illustrates how fractures can be used in relative dating of a surface. The fractured materials on the right side of the image are embayed by younger volcanic flows originating to the west of the image. Note how the younger flows cover the ends of the fractures, and are not at all fractured themselves.

    Image information: VIS instrument. Latitude 43.2, Longitude 269.4 East (90.6 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  18. Phase Field Fracture Mechanics.

    SciTech Connect

    Robertson, Brett Anthony

    2015-11-01

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

  19. Freeze-fracture-autoradiography.

    PubMed

    Rix, E; Schiller, A; Taugner, R

    A new method for the electron microscope autoradiography of soluble substances in frozen tissue is described. The basic features of the method are freeze fracturing, the application of a suitable monolayer followed by exposure at low temperature and finally the separation of tissue and the replica-monolayer-sandwich after photographic processing. The advantages and limitations of the new method are discussed in terms of monolayer quality, contact, histochemography, resolution, freezing and recrystallisation artefacts.

  20. On fracture toughness evaluation for semi-brittle fracture

    NASA Technical Reports Server (NTRS)

    Eftis, J.; Liebowitz, H.

    1975-01-01

    The existing methods of assessing the fracture toughness of materials exhibiting semi-brittle fracture are critically reviewed. The methods concern the Crack Growth Resistance (R-curve), the Crack Opening Displacement (COD), and the J-integral. An analysis of the shortcomings of the methods described makes it possible to formulate a new definition of fracture toughness appropriate to semi-brittle fracture. An improved simple experimental method for measuring fracture toughness for semi-brittle fracture is proposed which takes into account both crack growth and plastic nonlinear effects at crack front. The proposed method is shown to be free of the theoretical and experimental discrepancies encountered in the R-curve, COD, and J-integral methods.

  1. Opportunistic Identification of Vertebral Fractures.

    PubMed

    Adams, Judith E

    2016-01-01

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

  2. Management of neglected acetabular fractures.

    PubMed

    Veerappa, L A; Tripathy, S K; Sen, R K

    2015-08-01

    Management of neglected acetabular fractures is a difficult task. Osteosynthesis in such cases may not be an ideal solution because of the femoral head damage due to pressure by the fractured acetabular edge, avascular necrosis, difficulty in mobilizing the fragments due to callus formation, difficulty in indirect reduction of the fracture fragments and macerated acetabular fragments all contributing to inadequate fracture reduction. Majority of such fractures are now treated with total hip replacement. While treating such fractures with THR, problems associated with neglected acetabular fractures such as fracture non-union, hip dislocation, protrusio, cavitary bone defect or peripheral bone defect must be considered. 3D computed tomography scan provides a clear view about the acetabular and periacetabular bony anatomy. Impaction grafting and antiprotrusio cage or ring with a cemented acetabular cup can address most of the hip protrusio and cavitary bone defects. Segmental bone defect needs cortical strut-bone graft fixation and subsequent implantation of a cemented or uncemented acetabular cup implantation. Fracture non-union needs approximate reduction and fixation with plates followed by bone grafting and implantation of an acetabular cup. Despite these efforts, the outcome of THR in neglected acetabular fracture is considerable worse than after conventional hip replacement.

  3. Fractured Craters on Ganymede

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Two highly fractured craters are visible in this high resolution image of Jupiter's moon, Ganymede. NASA's Galileo spacecraft imaged this region as it passed Ganymede during its second orbit through the Jovian system. North is to the top of the picture and the sun illuminates the surface from the southeast. The two craters in the center of the image lie in the ancient dark terrain of Marius Regio, at 40 degrees latitude and 201 degrees longitude, at the border of a region of bright grooved terrain known as Byblus Sulcus (the eastern portion of which is visible on the left of this image). Pervasive fracturing has occurred in this area that has completely disrupted these craters and destroyed their southern and western walls. Such intense fracturing has occurred over much of Ganymede's surface and has commonly destroyed older features. The image covers an area approximately 26 kilometers (16 miles) by 18 kilometers (11 miles) across at a resolution of 86 meters (287 feet) per picture element. The image was taken on September 6, 1996 by the solid state imaging (CCD) system on NASA's Galileo spacecraft.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.

  4. Fractures of the cervical spine

    PubMed Central

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

    2013-01-01

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

  5. Procedure for estimating fracture energy from fracture surface roughness

    DOEpatents

    Williford, Ralph E.

    1989-01-01

    The fracture energy of a material is determined by first measuring the length of a profile of a section through a fractured surface of the material taken on a plane perpendicular to the mean plane of that surface, then determining the fractal dimensionality of the surface. From this, the yield strength of the material, and the Young's Modulus of that material, the fracture energy is calculated.

  6. Prediction of Composite Laminate Fracture: Micromechanics and Progressive Fracture

    NASA Technical Reports Server (NTRS)

    Gotsis, P. K.; Chamis, C. C.; Minnetyan, L.

    1996-01-01

    This report describes an investigation to predict first-ply failure and final fracture in selected composite laminates subjected to inplane loads. The laminates were composed of glass fiber and graphite fibers in epoxy matrices. Failure envelopes based on first-ply failure and laminate fracture were generated for combined loading of these laminates. Predictions were evaluated by micromechanics-based theory and progressive fracture. The results show that, for most cases, combined tensile loading significantly enhanced the laminate fracture stress in comparison to the uniaxial loading.

  7. Rock fracture image acquisition and analysis

    NASA Astrophysics Data System (ADS)

    Wang, W.; Zongpu, Jia; Chen, Liwan

    2007-12-01

    As a cooperation project between Sweden and China, this paper presents: rock fracture image acquisition and analysis. Rock fracture images are acquired by using UV light illumination and visible optical illumination. To present fracture network reasonable, we set up some models to characterize the network, based on the models, we used Best fit Ferret method to auto-determine fracture zone, then, through skeleton fractures to obtain endpoints, junctions, holes, particles, and branches. Based on the new parameters and a part of common parameters, the fracture network density, porosity, connectivity and complexities can be obtained, and the fracture network is characterized. In the following, we first present a basic consideration and basic parameters for fractures (Primary study of characteristics of rock fractures), then, set up a model for fracture network analysis (Fracture network analysis), consequently to use the model to analyze fracture network with different images (Two dimensional fracture network analysis based on slices), and finally give conclusions and suggestions.

  8. FRACTURED PETROLEUM RESERVOIRS

    SciTech Connect

    Abbas Firoozabadi

    1999-06-11

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

  9. [METHOD OF OSTEOSYNTHESIS OF SUPRACONDULAR FRACTURES OF THE HUMERUS].

    PubMed

    Neverov, V A; Chernyaev, S N; Shinkarenko, D V

    2015-01-01

    A treatment of fractures of distal metadiaphysis of the humeral bone remains an actual problem of modern traumatology at present time. This is associated with immediate proximity of the radial nerve and risk of iatrogenic injury in external fixation, presence of short distal fragment, comminuted nature of fracture, complexity of treatment method selection, need of extensible approach. Biomechanical features of different fixators were analyzed in consideration of presence of short distal fragment, traumatic of. external fixation and risk of iatrogenic injury of the nerve. The authors suggested the method of osteosynthesis of the humerus by using blocking osteosynthesis with preliminary extension of intra-medullary canal of distal fragment for obtaining stable osteosynthesis (priority No 2014105323 from 14.02.2014). The proposed method allowed avoiding the iatrogenic neuropathy of the radial nerve, providing the stability of fixation higher, than in case of external fixation. It excludes the need of external immobilization and combines the period of bony union with the period of rehabilitation and socially integrates the patient in minimal terms.

  10. Management of fractures in adolescents.

    PubMed

    Parikh, Shital N; Wells, Lawrence; Mehlman, Charles T; Scherl, Susan A

    2011-01-01

    There are well-established treatment standards for adults who sustain fractures; however, these treatment standards are not always applicable when treating adolescents with similar fractures because of the presence of physes. Fractures in adolescents are treated by pediatric orthopaedic surgeons, adult orthopaedic traumatologists, or general orthopaedic surgeons. It is imperative that the principles of fracture management are well defined and discussed in both the pediatric and adult orthopaedic community. Controversial topics include the youngest age at which an adolescent can be treated as an adult and acceptable fracture reduction criteria. The general principles of managing fractures in adolescents regarding classification, treatment options, complications, and estimating skeletal age should be understood by the treating physician.

  11. Complex Fluids and Hydraulic Fracturing.

    PubMed

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

    2016-06-07

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

  12. Resistivity logging of fractured basalt

    SciTech Connect

    Stefansson, V.; Axelsson, G.; Sigurdsson, O.

    1982-01-01

    A lumped double porosity model was studied in order to estimate the effect of fractures on resistivity - porosity relations. It is found that the relationship between resistivity and porosity for fractured rock is in general not simple and depends both on the amounts of matrix porosity as well as the fracture orientation. However, when fractures dominate over matrix porosity the exponent is close to 1.0. Resistivity-porosity relations have been determined for large amounts of basaltic formations in Iceland. An exponent close to 1.0 is found in all cases investigated. This is interpreted as fractures constitute a considerable part of the porosity of the basalts. In the IRDP-hole in Eastern Iceland it is found that the ratio of fracture porosity to total porosity decreases with depth.

  13. Treatment rationale of fractured posterior teeth.

    PubMed

    Silvestri, A R; Singh, I

    1978-11-01

    The four types of fractures most frequently encountered in posterior teeth--obliquely directed complete fractures, vertically directed complete fractures, obliquely directed incomplete fractures, and vertically directed incomplete fractures--have been described. A detailed treatment approach for each type has been presented.

  14. Seismic determination of saturation in fractured reservoirs

    USGS Publications Warehouse

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

    2002-01-01

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

  15. Unusual presentation of a femoral stress fracture

    PubMed Central

    Ejnisman, Leandro; Wajnsztejn, Andre; Queiroz, Roberto Dantas; Ejnisman, Benno

    2013-01-01

    Stress fractures are common injuries in sports medicine. Among these fractures, femoral neck stress fractures frequently have a benign course, especially when it happens in the medial aspect of the neck. This case report describes a stress fracture of the medial aspect of the femoral neck that developed a complete fracture and underwent surgical fixation. PMID:23283621

  16. Fractured fibulae in broiler fowls.

    PubMed

    Duff, S R

    1985-10-01

    Fibular diaphyseal fractures were identified bilaterally or unilaterally in 15 broilers aged between 13 and 105 days. Incomplete cortical defects were also identified on radiographs in a further 8 birds. Fractures and incomplete defects always occurred at the Tuberculum M. iliofibularis of fibulae. The character of bone at this site differed from bone elsewhere in the diaphysis. Following fracture, cartilaginous callus united the diaphyseal segments and pseudarthrosis or fibrous non-union were common sequelae. The concept that fibular fractures in broilers are always a consequence of abnormal proximal tibiotarsal curvature is not supported by this study. It is suggested that differential growth of the paired crural bones is of primary importance.

  17. Materials and processes for Shuttle engine, external tank, and Solid Rocket Booster

    NASA Technical Reports Server (NTRS)

    Schwinghamer, R. J.

    1976-01-01

    The paper deals with the materials and processes for three Space Shuttle elements: Space Shuttle Main Engines (SSME), the External Tank (ET), and the Solid Rocket Boosters (SRB), beginning with an overview of the materials selection, tracking and control system. SSME materials and processes are considered with emphasis on hydrogen environment embrittlement, LOX/GOX compatibility, stress corrosion cracking, and hydraulic fluid testing and qualification. The ET is examined with attention given to welding and fracture mechanics, and the thermal protection system. The SRB is discussed with emphasis on corrosion prevention, stress corrosion and fracture toughness, the integrated test bed for in situ corrosion protection verification, aluminum processing, and the thermal protection system.

  18. Modeling and simulation of physical performance of a external unilateral mechatronic orthopaedic fixator - bone system.

    PubMed

    Lesniewska, A; Choromanski, W; Deszczynski, J; Dobrzynski, G

    2006-01-01

    Restricted element study of the fracture healing by external fixation device was investigated. The analyses were performed under an axial and variable loaded boundary conditions. The effect of different fracture size and different distance between bone and the external fixator device on the stress distribution was investigated. The results show that stresses in the external fixator device are highest at the beginning of the fracture healing process, and are gradually decreasing with the time of the treatment. The analyses were carried out using the commercial package CATIA P3 V5R11. This allowed to build a three-dimensional model more similar to the geometrical architecture of the long bone as well as of the external fixator. Three-dimensional restricted element model also allowed a collection of more realistic results. However, the accuracy of the results depends not only on the quality of the model geometry but also on the material properties assigned to the model components. It also depends on the accuracy in the simulation of the finite element model and the optimized mesh generation.

  19. Fatigue and fracture: Overview

    NASA Technical Reports Server (NTRS)

    Halford, G. R.

    1984-01-01

    A brief overview of the status of the fatigue and fracture programs is given. The programs involve the development of appropriate analytic material behavior models for cyclic stress-strain-temperature-time/cyclic crack initiation, and cyclic crack propagation. The underlying thrust of these programs is the development and verification of workable engineering methods for the calculation, in advance of service, of the local cyclic stress-strain response at the critical life governing location in hot section compounds, and the resultant crack initiation and crack growth lifetimes.

  20. Fractured petroleum reservoirs

    SciTech Connect

    Firoozabadi, A.; Chang, E.; Tang, G.Q.

    2000-01-10

    Total compressibility in a fractured reservoir is estimated using the pressure response due to gravitational potential variations. Both the moon and the sun gravitational potentials are accounted for using the full expression by inclusion of longer-period components. The semi-diurnal and diurnal pressure data show substantial long-term variations. The gravitational potential also contains the same variation trend; the ratio between the potential and pressure has a fairly uniform value over successive cycles. The computed total compressibility is also fairly constant and independent of the cycle. Results show the effects of the time interval over which the pressure measurements are performed as well as the location.

  1. Fracturing And Liquid CONvection

    SciTech Connect

    2012-02-29

    FALCON has been developed to enable simulation of the tightly coupled fluid-rock behavior in hydrothermal and engineered geothermal system (EGS) reservoirs, targeting the dynamics of fracture stimulation, fluid flow, rock deformation, and heat transport in a single integrated code, with the ultimate goal of providing a tool that can be used to test the viability of EGS in the United States and worldwide. Reliable reservoir performance predictions of EGS systems require accurate and robust modeling for the coupled thermal­hydrological­mechanical processes.

  2. Martian external magnetic field proxies

    NASA Astrophysics Data System (ADS)

    Langlais, Benoit; Civet, Francois

    2015-04-01

    Mars possesses no dynamic magnetic field of internal origin as it is the case for the Earth or for Mercury. Instead Mars is characterized by an intense and localized magnetic field of crustal origin. This field is the result of past magnetization and demagnetization processes, and reflects its evolution. The Interplanetary Magnetic Field (IMF) interacts with Mars' ionized environment to create an external magnetic field. This external field is weak compared to lithospheric one but very dynamic, and may hamper the detailed analysis of the internal magnetic field at some places or times. Because there are currently no magnetic field measurements made at Mars' surface, it is not possible to directly monitor the external field temporal variability as it is done in Earth's ground magnetic observatories. In this study we examine to indirect ways of quantifying this external field. First we use the Advanced Composition Explorer (ACE) mission which measures the solar wind about one hour upstream of the bow-shock resulting from the interaction between the solar wind and the Earth's internal magnetic field. These measurements are extrapolated to Mars' position taking into account the orbital configurations of the Mars-Earth system and the velocity of particles carrying the IMF. Second we directly use Mars Global Surveyor magnetic field measurements to quantify the level of variability of the external field. We subtract from the measurements the internal field which is otherwise modeled, and bin the residuals first on a spatial and then on a temporal mesh. This allows to compute daily or semi daily index. We present a comparison of these two proxies and demonstrate their complementarity. We also illustrate our analysis by comparing our Martian external field proxies to terrestrial index at epochs of known strong activity. These proxies will especially be useful for upcoming magnetic field measurements made around or at the surface of Mars.

  3. Gravity-Driven Hydraulic Fractures

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  4. Closed reduction of a fractured bone

    MedlinePlus

    Fracture reduction - closed ... pain medicine you receive. There may be new fractures that occur with the reduction. If the reduction ... BD, Jupiter JBl, Krettek C, Anderson PA. Closed fracture management. In: Browner BD, Jupiter JB, Krettek C, ...

  5. Space station neutral external environment

    NASA Technical Reports Server (NTRS)

    Ehlers, H.; Leger, L.

    1988-01-01

    Molecular contamination levels arising from the external induced neutral environment of the Space Station (Phase 1 configuration) were calculated using the MOLFLUX model. Predicted molecular column densities and deposition rates generally meet the Space Station contamination requirements. In the doubtful cases of deposition due to materials outgassing, proper material selection, generally excluding organic products exposed to the external environment, must be considered to meet contamination requirements. It is important that the Space Station configuration, once defined, is not significantly modified to avoid introducing new unacceptable contamination sources.

  6. External hydrocephalus in two cats.

    PubMed

    Dewey, Curtis W; Coates, Joan R; Ducoté, Julie M; Stefanacci, Joseph D; Walker, Michael A; Marino, Dominic J

    2003-01-01

    External hydrocephalus describes an accumulation of cerebrospinal fluid (CSF) between the cerebral hemispheres and the overlying arachnoid membrane, rather than within the lateral ventricles. Two young cats with encephalopathic signs were diagnosed with external hydrocephalus, one via magnetic resonance imaging and one via computed tomography. Both cats had abnormally large, broad heads, with no evidence of open fontanelles. A surgical shunt was placed in each cat to divert the accumulated CSF within the cranial cavity to the peritoneal space. Both cats improved dramatically soon after surgical shunting was performed, and they continue to do well clinically, approximately 42 months and 8 months postoperatively, respectively.

  7. Unilateral lag-screw technique for an isolated anterior 1/4 atlas fracture

    PubMed Central

    Keskil, Semih; Göksel, Murat; Yüksel, Ulaş

    2016-01-01

    Study Design: Fractures of the atlas are classified based on the fracture location and associated ligamentous injury. Among patients with atlas fractures treated using external immobilization, nonunion of the fracture could be seen. Objective: Ideally, treatment strategy for an unstable atlas fracture would involve limited fixation to maintain the fracture fragments in a reduced position without restricting the range of motion (ROM) of the atlantoaxial and atlantooccipital joints. Summary of Background Data: Such a result can be established using either transoral limited internal fixation or limited posterior lateral mass fixation. However, due to high infection risk and technical difficulty, posterior approaches are preferred but none of these techniques can fully address anterior 1/4 atlas fractures such as in this case. Materials and Methods: A novel open and direct technique in which a unilateral lag screw was placed to reduce and stabilize a progressively widening isolated right-sided anterior 1/4 single fracture of C1 that was initially treated with a rigid cervical collar is described. Results: Radiological studies made after the surgery showed no implant failure, good cervical alignment, and good reduction with fusion of C1. Conclusions: It is suggested that isolated C1 fractures can be surgically reduced and immobilized using a lateral compression screw to allow union and maintain both C1-0 and C1-2 motions, and in our knowledge this is the first description of the use of a lag screw to achieve reduction of distracted anterior 1/4 fracture fragments of the C1 from a posterior approach. This technique has the potential to become a valuable adjunct to the surgeon's armamentarium, in our opinion, only for fractures with distracted or comminuted fragments whose alignment would not be expected to significantly change with classical lateral mass screw reduction. PMID:27041886

  8. Locking plate fixation of distal femoral fractures is a challenging technique: a retrospective review

    PubMed Central

    Toro, Giuseppe; Calabrò, Giampiero; Toro, Antonio; de Sire, Alessandro; Iolascon, Giovanni

    2015-01-01

    Summary Distal femoral fractures have typically a bimodal occurrence: in young people due to a high-energy trauma and in older people related to a low-energy trauma. These fractures are associated to a very high morbidity and mortality in elderly. Distal femoral fractures might be treated with plates, intramedullary nails, external fixations, and prosthesis. However, difficulties in fracture healing and the rate of complications are important clinical issues. The purpose of this retrospective review was to present our experience in treatment of distal femoral fracture in a sample of older people in order to evaluate the technical pitfalls and strategies used to face up the fractures unsuccessfully treated with locking plates. We included people aged more than 65 years, with a diagnosis of distal femoral fracture, treated with locking plates. We considered ‘unsuccessfully treated’ the cases with healing problems or hardware failures. Of the 12 patients (9 females and 3 males; mean aged 68.75 ± 3.31 years) included, we observed 3 ‘unsuccessfully cases’, 2 due to nonunions and 1 due to an early hardware failure, all treated using a condylar blade plate with a bone graft. One patient obtained a complete fracture healing after 1 year and in the other cases there was a nonunion. We observed as most common technical pitfalls: inadequate plate lengthening, fracture bridging, and number of locking screws. The use of locking plates is an emerging technique to treat these fractures but it seems more challenging than expected. In literature there is a lack of evidences about the surgical management of distal femoral fractures that is still an important challenge for the orthopaedic surgeon that has to be able to use all the fixation devices available. PMID:27134634

  9. Taylor spatial frame in the treatment of open tibial shaft fractures

    PubMed Central

    Al-Sayyad, Mohammed J

    2008-01-01

    Background: The Taylor spatial frame (TSF) is a modern multiplanar external fixator that combines the ease of application and computer accuracy in the reduction of fractures. A retrospective review of our prospective TSF database for the use of this device for treating open tibial fractures in pediatric, adolescent, and adult patients was carried out to determine the effectiveness and complications of TSF in the treatment of these fractures. Materials and Methods: Nineteen male patients with open tibial fractures were included. Of these fractures, 10 were Gustilo Type II, five were Gustilo Type IIIA (two had delayed primary closure and three had split thickness skin grafting), and four were Gustilo Type IIIB (all had rotational flaps). Twelve of our patients presented immediately to the emergency room, and the remaining seven cases presented at a mean of 3 months (range, 2.2-4.5 months) after the initial injury. The fractures were located in proximal third (n=1), proximal/middle junction (n=2), middle third (n=3), middle/distal junction (n=8), distal third (n=3), and segmental fractures (n=2). Patients were of an average age of 26 years (range, 6-45years). Mean duration of follow-up was 3.5 years. Results: All fractures healed over a mean of 25 weeks (range, 9-46 weeks). All were able to participate in the activities of daily living without any difficulty and most were involved in sports during the last follow-up. Postoperative complications included pin tract infection in 12 patients. Conclusion: The TSF is an effective definitive method of open tibial fracture care with the advantage of early mobilization, ease of soft tissue management through gradual fracture reduction, and the ability to postoperatively manipulate the fracture into excellent alignment. PMID:19753231

  10. Discrete element modeling of rock deformation, fracture network development and permeability evolution under hydraulic stimulation

    SciTech Connect

    Shouchun Deng; Robert Podgorney; Hai Huang

    2011-02-01

    Key challenges associated with the EGS reservoir development include the ability to reliably predict hydraulic fracturing and the deformation of natural fractures as well as estimating permeability evolution of the fracture network with time. We have developed a physics-based rock deformation and fracture propagation simulator by coupling a discrete element model (DEM) for fracturing with a network flow model. In DEM model, solid rock is represented by a network of discrete elements (often referred as particles) connected by various types of mechanical bonds such as springs, elastic beams or bonds that have more complex properties (such as stress-dependent elastic constants). Fracturing is represented explicitly as broken bonds (microcracks), which form and coalesce into macroscopic fractures when external and internal load is applied. The natural fractures are represented by a series of connected line segments. Mechanical bonds that intersect with such line segments are removed from the DEM model. A network flow model using conjugate lattice to the DEM network is developed and coupled with the DEM. The fluid pressure gradient exerts forces on individual elements of the DEM network, which therefore deforms the mechanical bonds and breaks them if the deformation reaches a prescribed threshold value. Such deformation/fracturing in turn changes the permeability of the flow network, which again changes the evolution of fluid pressure, intimately coupling the two processes. The intimate coupling between fracturing/deformation of fracture networks and fluid flow makes the meso-scale DEM- network flow simulations necessary in order to accurately evaluate the permeability evolution, as these methods have substantial advantages over conventional continuum mechanical models of elastic rock deformation. The challenges that must be overcome to simulate EGS reservoir stimulation, preliminary results, progress to date and near future research directions and opportunities will be

  11. Rock fracture processes in chemically reactive environments

    NASA Astrophysics Data System (ADS)

    Eichhubl, P.

    2015-12-01

    Rock fracture is traditionally viewed as a brittle process involving damage nucleation and growth in a zone ahead of a larger fracture, resulting in fracture propagation once a threshold loading stress is exceeded. It is now increasingly recognized that coupled chemical-mechanical processes influence fracture growth in wide range of subsurface conditions that include igneous, metamorphic, and geothermal systems, and diagenetically reactive sedimentary systems with possible applications to hydrocarbon extraction and CO2 sequestration. Fracture processes aided or driven by chemical change can affect the onset of fracture, fracture shape and branching characteristics, and fracture network geometry, thus influencing mechanical strength and flow properties of rock systems. We are investigating two fundamental modes of chemical-mechanical interactions associated with fracture growth: 1. Fracture propagation may be aided by chemical dissolution or hydration reactions at the fracture tip allowing fracture propagation under subcritical stress loading conditions. We are evaluating effects of environmental conditions on critical (fracture toughness KIc) and subcritical (subcritical index) fracture properties using double torsion fracture mechanics tests on shale and sandstone. Depending on rock composition, the presence of reactive aqueous fluids can increase or decrease KIc and/or subcritical index. 2. Fracture may be concurrent with distributed dissolution-precipitation reactions in the hostrock beyond the immediate vicinity of the fracture tip. Reconstructing the fracture opening history recorded in crack-seal fracture cement of deeply buried sandstone we find that fracture length growth and fracture opening can be decoupled, with a phase of initial length growth followed by a phase of dominant fracture opening. This suggests that mechanical crack-tip failure processes, possibly aided by chemical crack-tip weakening, and distributed

  12. Fracture Detection and Mapping

    SciTech Connect

    Goldstein, Norman E.; Iovenitti, Joseph L.

    1986-01-21

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

  13. Fracture detection and mapping

    SciTech Connect

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

    1986-03-01

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

  14. [Fractures of the distal radius].

    PubMed

    Rueger, J M; Hartel, M J; Ruecker, A H; Hoffmann, M

    2014-11-01

    The most prevalent fractures managed by trauma surgeons are those involving the distal radius. The injury occurs in two peaks of prevalence: the first peak around the age of 10 years and the second peak around the age of 60 years. Distal radius fracture management requires sensitive diagnostics and classification. The objectives of treatment are the reconstruction of a pain-free unlimited durable functioning of the wrist and avoidance of typical fracture complications. Non-operative conservative management is generally employed for stable non-displaced fractures of the distal radius with the expectation of a good functional outcome. Unstable comminuted fractures with intra-articular and extra-articular fragment zones are initially set in a closed operation and finally by osteosynthesis. An armament of surgical implants is available for instable fractures requiring fixation. Palmar locked plate osteosynthesis has been established in recent years as the gold standard for operative management of distal radius fractures. Complex Working Group on Osteosynthesis (AO) classification type 3 fractures require extensive preoperative diagnostics to identify and treat typical associated injuries around the wrist.

  15. Experimental study of high-energy fractures delayed operation in promote bone healing

    PubMed Central

    Pan, Zhi-Jun; Li, Zhong; Li, Jing

    2015-01-01

    To investigate role of delayed operation to stimulate growth of strong external callus in high-energy fractures, and explore a new way for bone healing. Twenty adult dogs were employed, and randomly divided into four groups, including group A-D. The dogs underwent osteotomy by wire saw in middle of femur, electric coagulation damaged surrounding periosteum, forming a 1 cm defect. Group A were internal fixed 14 days after osteotomy (higher-energy fractures delayed operation), Group B and C were internal fixed immediately (no delayed operation), Group D were internal fixed 14 days after osteotomy (delayed operation, but resected granulations around extremities). The results showed that groups of early fixed have no external callus growth and almost no growth in internal callus, these conditions leads to atrophy nonunion. On contrary, the porosis was strong and callus union was steady in group A and D, which have a delayed operation. In conclusion, early surgical fixation of high-energy fracture restrains external callus growth, easily lead to poor callus healing phenomenon of low-quality. Delayed surgical fixation can begin to repair soft tissues injury, stimulate external callus growth and improve fracture healing, so a small incision open reduction produce more robust growth effect than closed reduction. PMID:26379852

  16. Outcome of closed proximal phalangeal fractures of the hand

    PubMed Central

    Singh, Jaswinder; Jain, Karun; Mruthyunjaya; Ravishankar, R

    2011-01-01

    Background: The proximal phalanx (PP) of the fingers is fractured more frequently than the middle or even distal phalanges. The problems of malunion, stiffness and sometimes loss of skin or other soft tissues associated with PP fracture increases the disability. The optimum treatment depends on fracture location, fracture geometry and fracture stability. The objective of the study was to analyse the treatment outcome in a series of closed proximal phalangeal fractures of the hand. Materials and Methods: Eighty-four proximal phalangeal fractures in 68 patients were enrolled from 2007 to 2009. The treatment modalities were broadly categorised into two groups, Group A consisted of conservative treatment, and Group B consisted of surgical treatment. Group A included 47 digits treated with closed reduction (CR) with immobilization (n=43), extension block cast and dynamic traction (n=4), while 37 digits were treated in Group B, which included closed or open reduction (OR) and internal fixation (IF) with K-wires (n=31), OR and IF with stainless-steel wiring (n=2), and mini external-fixator (n=4). Belsky's criteria and Gingrass’ criteria were used for assessment of finger injuries and to assess the efficacy of conservative and surgical modalities for closed proximal phalangeal fractures of the hand. Results: Average period of follow-up was 1 year (range 10-14 months). The excellent to good results seen in Groups A and B were 89% and 92%, respectively. Six complications were seen in Group A, which included four cases with malunion and two cases with digital stiffness. Three complications were seen in Group B, which included one each of malunion, digital stiffness and extensor lag. Overall, maximum poor results (n=4) were seen with CR and buddy strapping. Conclusion: Conservative treatment is an inexpensive method, particularly suitable for stable fractures, and in patients who are poor candidates for surgery, Surgical modalities have distinct advantage of stable fixation

  17. [Treatment by external insulin pump].

    PubMed

    Clavel, Sylvaine

    2010-12-01

    Since the recent recommendations by the French speaking association for research on diabetes and metabolic illnesses (Alfediam), treatment by insulin pump has found itself in competition with basal-bolus, a procedure using similar injections of insulin which has become a benchmark treatment. The latest Alfediam guidelines focus on defining ways of treating diabetics with an external insulin pump.

  18. Lupus vulgaris of external nose.

    PubMed

    Bhandary, Satheesh Kumar; Ranganna, B Usha

    2008-12-01

    Lupus vulgaris is the commonest form of cutaneous tuberculosis which commonly involve trunk and buttocks. Lupus vulgaris affecting nose and face, are rarely reported in India. This study reports an unusual case of lupus vulgaris involving the external nose that showed dramatic outcome after six months of anti- tubercular treatment.

  19. External Communication. SPEC Kit 56.

    ERIC Educational Resources Information Center

    Association of Research Libraries, Washington, DC. Office of Management Studies.

    One section of a spring 1979 Systems and Procedures Exchange Center (SPEC) survey on communication in Association of Research Libraries (ARL) institutions examined how members exchange information with external groups including the university administration, faculty, users, support groups, other libraries, and the profession in general. According…

  20. 10 Core External Environmental Trends.

    ERIC Educational Resources Information Center

    El Camino Coll., Torrance, CA.

    This is an institutional report summarizing 10 core external environmental trends and their implications for El Camino College and the surrounding community. The report offers a brief description for the following trends: (1) there is more emphasis on colleges becoming learning institutions rather than teaching institutions; (2) the current and…

  1. [Prostate cancer external beam radiotherapy].

    PubMed

    de Crevoisier, R; Pommier, P; Latorzeff, I; Chapet, O; Chauvet, B; Hennequin, C

    2016-09-01

    The prostate external beam radiotherapy techniques are described, when irradiating the prostate or after prostatectomy, with and without pelvic lymph nodes. The following parts are presented: indications of radiotherapy, total dose and fractionation, planning CT image acquisition, volume of interest delineation (target volumes and organs at risk) and margins, Intensity modulated radiotherapy planning and corresponding dose-volume constraints, and finally Image guided radiotherapy.

  2. Internal to external wavelength calibration

    NASA Astrophysics Data System (ADS)

    Sahu, Kailash C.

    1999-01-01

    The spectra of Hen 1357 (the Stingray nebula) were used to check the internal to external wavelength calibration of the STIS first order CCD modes. The radial velocity of the Stingray nebula is known to high accuracy (< 1 km/sec) and the line with of the nebular line is very narrow (< 8 km/sec for the integrated nebula). Thus the observations of the Stingray nebula are ideal to check the internal to external wavelength calibration of the first order modes. The observations were taken in G430L and G750M modes using a 52 x 0.05 arcsec slit covering the wavelength range 2900 to 5700 A and 6295 to 6867 A, respectively. The observed wavelength range includes many nebular emission lines. The wavelengths of the nebular lines derived using the pipeline internal wavelength calibration were compared with the wavelengths derived from other ground based observations. In all cases, the wavelength match between the two is of the same order as the accuracy to which the line center can be measured. These results imply that there is no significant offset between the internal and external wavelength calibrations for these modes. The HDF-S QSO observations were also used for this test both for the first order and the Echelle modes. The results of the HDF-S QSO observations further confirm the above finding for the first order modes, and imply that there is no significant offset between the internal and external wavelength calibration for the Echelle modes.

  3. [Distal radius fractures in children].

    PubMed

    Otayek, S; Ramanoudjame, M; Fitoussi, F

    2016-12-01

    Metaphyseal and physeal fractures of the distal radius are common in children. Most cases are best treated with closed reduction and cast immobilization. Long-term outcomes of these injuries are excellent when specific treatment principles of reduction and casting are followed. Surgical indications are limited and include open fractures, intra-articular fractures, non-reducible fractures, unstable fractures, and the presence of associated nerve injury. Closed reduction and percutaneous pin fixation is the most commonly used surgical option. The clinician should be aware of delayed complications such as growth disturbance of the distal radius, and understand how to manage these problems to ensure successful long-term outcomes. Epiphysiodesis is uncommon but growth plate injuries need to be followed for one year.

  4. Lithospheric flexure at fracture zones

    NASA Technical Reports Server (NTRS)

    Sandwell, D.; Schubert, G.

    1982-01-01

    Studies attempting to demonstrate that lithospheric flexure occurs across the Pioneer and Mendocino fracture zones, and that the flexural topography is a topographic expression at these fracture zones, are presented. The flexure is modelled and compared with predicted depths with five bathymetric profiles which cross the two fracture zones at different ages. The model uses a thin elastic plate overlying an incompressible fluid half-space, and incorporates a temperature-dependent effective elastic thickness. Several conclusions were derived from this study. First, it is found that no significant slip on the fossil fault planes of the Mendocino and Pioneer fracture zones exists. In addition, the flexural amplitude is determined to increase with age. Finally, it is concluded that there is elastic coupling between the Mendocino and Pioneer fracture zones since the separation is less than a flexural wavelength.

  5. Pathogenesis of osteoporotic hip fractures.

    PubMed

    McClung, Michael R

    2003-01-01

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

  6. Test-Free Fracture Toughness

    NASA Technical Reports Server (NTRS)

    Minnetyan, Levon; Chamis, Christos C. (Technical Monitor)

    2003-01-01

    Computational simulation results can give the prediction of damage growth and progression and fracture toughness of composite structures. The experimental data from literature provide environmental effects on the fracture behavior of metallic or fiber composite structures. However, the traditional experimental methods to analyze the influence of the imposed conditions are expensive and time consuming. This research used the CODSTRAN code to model the temperature effects, scaling effects and the loading effects of fiberbraided composite specimens with and without fiber-optic sensors on the damage initiation and energy release rates. The load-displacement relationship and fracture toughness assessment approach is compared with the test results from literature and it is verified that the computational simulation, with the use of established material modeling and finite element modules, adequately tracks the changes of fracture toughness and subsequent fracture propagation for any fiberbraided composite structure due to the change of fiber orientations, presence of large diameter optical fibers, and any loading conditions.

  7. Distal clavicle fractures in children☆

    PubMed Central

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

    2015-01-01

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

  8. Ankle fractures in elderly patients.

    PubMed

    Giannini, Sandro; Chiarello, Eugenio; Persiani, Valentina; Luciani, Deianira; Cadossi, Matteo; Tedesco, Giuseppe

    2013-10-01

    The incidence of ankle fractures (AFs) in the elderly is rising due to the increase in life expectancy. Rather than directly related to osteoporosis, AFs are a predictor of osteoporotic fractures in other sites. In women AFs are associated with weight and BMI. AFs are difficult to categorize; therapeutic options are non-operative treatment with plaster casts or surgical treatment with Kirschner's wires, plates and screws. The choice of treatment should be based not only on the fracture type but also on the local and general comorbidity of the patient. Considering the new evidence that postmenopausal women with AFs have disrupted microarchitecture and decreased stiffness of the bone compared with women with no fracture history, in our opinion low-trauma AFs should be considered in a similar way to the other classical osteoporotic fractures.

  9. Cannulated screw and hexapodal fixator reconstruction for compound upper tibial fractures

    PubMed Central

    Uzun, Metin; Bilen, Fikri Erkal; Eralp, Levent

    2014-01-01

    Objectives: The aim of the treatment of tibial plateau fractures is to obtain a pain-free and fully functional knee with closed reduction, percutaneous cannulated screw fixation and hexapodal external fixator reconstruction for high energy compound upper tibial fractures. Methods: Patients with comminuted tibial plateau fractures underwent closed reduction, percutaneous fixation with cannulated screws, and reconstruction with hexapodal external fixator. The follow-up period was 24 months. Results: The clinical and radiological results were good or excellent. The average knee flexion was 125°. Conclusion: Our results are successful in the initial stage, however, it should be pointed out that during the long term follow-up osteoarthritis may develop leading to worsening of the condition. Level of Evidence IV, Case Series. PMID:24644420

  10. Relative Permeability of Fractured Rock

    SciTech Connect

    Mark D. Habana

    2002-06-30

    Contemporary understanding of multiphase flow through fractures is limited. Different studies using synthetic fractures and various fluids have yielded different relative permeability-saturation relations. This study aimed to extend the understanding of multiphase flow by conducting nitrogen-water relative permeability experiments on a naturally-fractured rock from The Geysers geothermal field. The steady-state approach was used. However, steady state was achieved only at the endpoint saturations. Several difficulties were encountered that are attributed to phase interference and changes in fracture aperture and surface roughness, along with fracture propagation/initiation. Absolute permeabilities were determined using nitrogen and water. The permeability values obtained change with the number of load cycles. Determining the absolute permeability of a core is especially important in a fractured rock. The rock may change as asperities are destroyed and fractures propagate or st rain harden as the net stresses vary. Pressure spikes occurred in water a solute permeability experiments. Conceptual models of an elastic fracture network can explain the pressure spike behavior. At the endpoint saturations the water relative permeabilities obtained are much less than the nitrogen gas relative permeabilities. Saturations were determined by weighing and by resistivity calculations. The resistivity-saturation relationship developed for the core gave saturation values that differ by 5% from the value determined by weighing. Further work is required to complete the relative permeability curve. The steady-state experimental approach encountered difficulties due to phase interference and fracture change. Steady state may not be reached until an impractical length of time. Thus, unsteady-state methods should be pursued. In unsteady-state experiments the challenge will be in quantifying rock fracture change in addition to fluid flow changes.

  11. 14 CFR 27.865 - External loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false External loads. 27.865 Section 27.865... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction External Loads § 27.865 External loads. (a) It must be shown by analysis, test, or both, that the rotorcraft external load attaching means...

  12. 14 CFR 29.865 - External loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false External loads. 29.865 Section 29.865... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction External Loads § 29.865 External loads. (a) It must be shown by analysis, test, or both, that the rotorcraft external load attaching means...

  13. 14 CFR 29.865 - External loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false External loads. 29.865 Section 29.865... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction External Loads § 29.865 External loads. (a) It must be shown by analysis, test, or both, that the rotorcraft external load attaching means...

  14. 14 CFR 29.865 - External loads.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false External loads. 29.865 Section 29.865... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction External Loads § 29.865 External loads. (a) It must be shown by analysis, test, or both, that the rotorcraft external load attaching means...

  15. 14 CFR 27.865 - External loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false External loads. 27.865 Section 27.865... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction External Loads § 27.865 External loads. (a) It must be shown by analysis, test, or both, that the rotorcraft external load attaching means...

  16. 14 CFR 27.865 - External loads.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false External loads. 27.865 Section 27.865... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction External Loads § 27.865 External loads. (a) It must be shown by analysis, test, or both, that the rotorcraft external load attaching means...

  17. Fracture size scaling of hydraulic fracture stimulations in shale reservoirs

    NASA Astrophysics Data System (ADS)

    Urbancic, T.; Baig, A. M.

    2014-12-01

    It is becoming widely evident that hydraulic fracture stimulations in shale reservoirs can result in the generation of events with magnitudes M>0. These events are of concern both to the public as potential geo-hazards possibly affecting groundwater conditions and surface infra-structure, and to engineers for optimizing productivity and engineering design. Typically, in these environments, recording bandwidth limitations has resulted in a bias towards the consideration of events with M<0. This in turn has limited the observable fracture sizes to those constrained within lithological units. By extending the recording bandwidth to lower frequencies, the dimensions of the observable fractures are also extended to include larger fractures/faults activated during the stimulation. Our observations suggest that these larger-scale events can contribute upwards of 80% of the overall seismic budget or energy release associated with the stimulation process. Effective analysis of scaling relations independent of recording further suggests that breakdowns in scaling can be related to the presence of barriers to growth such as contrasts in rock properties associated with different lithological units. Generally, detected larger-magnitude events are associated with smaller-magnitude events, M<0, suggesting that these latter events can be used to characterize aspects of the rupture process whereas their associated signals observed with the low-frequency network can be used to characterize the overall fracture/fault behavior. By accounting for the presence of larger events, additional activated fracture surface area within the reservoir results in a significant increase in surface area. In an example provided, these events account for a further ~10 km2 of additional activated fracture surface area than estimated based on only utilizing high-frequency band-limited recordings. Overall, the identification of the actual discrete fracture network over many size scales allows for a better

  18. [Bone fracture and the healing mechanisms. Pathophysiology and classification of osteoporotic fractures].

    PubMed

    Kishimoto, Hideaki

    2009-05-01

    Bone provides momentary strength and fatigue strength, and bone strength decreases with age. In elderly men and women with fragile bones osteoporotic fractures frequently occur. Fragility fracture occurs as a consequence of the decrease in momentary strength, and fragility fracture is one of the pathological fractures. In patients with the decrease in fatigue strength, insufficiency fractures frequently occurs. Insufficiency fracture is the same term as stress or fatigue fracture.

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

    PubMed Central

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

    2015-01-01

    First rib fractures are scarce due to their well-protected anatomic locations. Bilateral first rib fractures accompanying bilateral scapular fractures are very rare, although they may be together with scapular and clavicular fractures. According to our knowledge, no case of bilateral first rib fractures accompanying bilateral scapular fractures has been reported, so we herein discussed the diagnosis, treatment, and complications of bone fractures due to thoracic trauma in bias of this rare entity. PMID:26175916

  20. Mechanisms of intergranular fracture

    SciTech Connect

    Farkas, D.

    1999-08-01

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

  1. Intramedullary bone cementing for the treatment of Colles fracture in elderly patients.

    PubMed

    Ikeda, Kazuo; Osamura, Naoki; Hagiwara, Norio; Yamauchi, Daisuke; Tomita, Katsuro

    2004-01-01

    Eighteen patients with Colles fractures, mean age 70 years (range 55-91), were treated by intramedullary bone cementing. The best indication for this technique was an unstable extra-articular Colles fracture with osteoporosis. Bone cement was packed into the canal that was made by curettage of intramedullary cancellous bone from the dorsal fracture site. Intramedullary cementing caused little bleeding from the medullary canal and no irritation of the extensor tendons. Because of rigid fixation, patients could use the affected hand for light activities without any external orthosis the day after surgery. Cortical healing was seen in all cases within three months and there was no cement loosening or other complications during the mean 28 month (range 6-43) follow up period. Intramedullary bone cementing is one of the optimal treatments for Colles fractures in elderly patients.

  2. The overlooked side of convulsion: bilateral posterior fracture and dislocation of proximal humerus.

    PubMed

    Yigit, Mehmet; Yaman, Asli; Yigit, Eda; Turkdogan, Kenan Ahmet

    2016-05-01

    Injuries after an epileptic convulsion have been seen commonly such as burns, head injury and dislocation of the extremities. But fractures of the extremities due to convulsion are rare. External trauma mechanism is not necessary for extremity fractures. Muscle contractions can cause increased load on the skeleton and it can be complicated by dislocation andor fracture of extremities. Almost 1-4% of all the shoulder dislocations are posterior. In this case report we present a 32 year old male patient who had bilateral posterior fracture and dislocation of proximal humerus after convulsion. We would like to emphasize that it is so important to make systemic examination and evaluation of the patients who were admitted to emergency department after epileptic convulsion.

  3. Fracture toughness anisotropy in shale

    NASA Astrophysics Data System (ADS)

    Chandler, Michael R.; Meredith, Philip G.; Brantut, Nicolas; Crawford, Brian R.

    2016-03-01

    The use of hydraulic fracturing to recover shale gas has focused attention on the fundamental fracture properties of gas-bearing shales, but there remains a paucity of available experimental data on their mechanical and physical properties. Such shales are strongly anisotropic, so that their fracture propagation trajectories depend on the interaction between their anisotropic mechanical properties and the anisotropic in situ stress field in the shallow crust. Here we report fracture toughness measurements on Mancos shale determined in all three principal fracture orientations: Divider, Short Transverse, and Arrester, using a modified short-rod methodology. Experimental results for a range of other sedimentary and carbonate rocks are also reported for comparison purposes. Significant anisotropy is observed in shale fracture toughness measurements at ambient conditions, with values, as high as 0.72 MPa m1/2 where the crack plane is normal to the bedding, and values as low as 0.21 MPa m1/2 where the crack plane is parallel to the bedding. For cracks propagating nonparallel to bedding, we observe a tendency for deviation toward the bedding-parallel orientation. Applying a maximum energy release rate criterion, we determined the conditions under which such deviations are more or less likely to occur under more generalized mixed-mode loading conditions. We find for Mancos shale that the fracture should deviate toward the plane with lowest toughness regardless of the loading conditions.

  4. Early history of scapular fractures.

    PubMed

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

    2016-01-01

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

  5. Fracture healing in osteoporotic bone.

    PubMed

    Cheung, Wing Hoi; Miclau, Theodore; Chow, Simon Kwoon-Ho; Yang, Frank F; Alt, Volker

    2016-06-01

    As the world population rises, osteoporotic fracture is an emerging global threat to the well-being of elderly patients. The process of fracture healing by intramembranous ossification or/and endochondral ossification involve many well-orchestrated events including the signaling, recruitment and differentiation of mesenchymal stem cells (MSCs) during the early phase; formation of a hard callus and extracellular matrix, angiogenesis and revascularization during the mid-phase; and finally callus remodeling at the late phase of fracture healing. Through clinical and animal research, many of these factors are shown to be impaired in osteoporotic bone. Animal studies related to post-menopausal estrogen deficient osteoporosis (type I) have shown healing to be prolonged with decreased levels of MSCs and decreased levels of angiogenesis. Moreover, the expression of estrogen receptor (ER) was shown to be delayed in ovariectomy-induced osteoporotic fracture. This might be related to the observed difference in mechanical sensitivity between normal and osteoporotic bones, which requires further experiments to elucidate. In mice fracture models related to senile osteoporosis (type II), it was observed that chondrocyte and osteoblast differentiation were impaired; and that transplantation of juvenile bone marrow would result in enhanced callus formation. Other factors related to angiogenesis and vasculogenesis have also been noted to be impaired in aged models, affecting the degradation of cartilaginous matrixes and vascular invasion; the result is changes in matrix composition and growth factors concentrations that ultimately impairs healing during age-related osteoporosis. Most osteoporotic related fractures occur at metaphyseal sites clinically, and reports have indicated that differences exist between diaphyseal and metaphyseal fractures. An animal model that satisfies three main criteria (metaphyseal region, plate fixation, osteoporosis) is suggested for future research for

  6. MGR External Events Hazards Analysis

    SciTech Connect

    L. Booth

    1999-11-06

    The purpose and objective of this analysis is to apply an external events Hazards Analysis (HA) to the License Application Design Selection Enhanced Design Alternative 11 [(LADS EDA II design (Reference 8.32))]. The output of the HA is called a Hazards List (HL). This analysis supersedes the external hazards portion of Rev. 00 of the PHA (Reference 8.1). The PHA for internal events will also be updated to the LADS EDA II design but under a separate analysis. Like the PHA methodology, the HA methodology provides a systematic method to identify potential hazards during the 100-year Monitored Geologic Repository (MGR) operating period updated to reflect the EDA II design. The resulting events on the HL are candidates that may have potential radiological consequences as determined during Design Basis Events (DBEs) analyses. Therefore, the HL that results from this analysis will undergo further screening and analysis based on the criteria that apply during the performance of DBE analyses.

  7. Multisystemic Therapy for Externalizing Youth

    PubMed Central

    Zajac, Kristyn; Randall, Jeff; Swenson, Cynthia Cupit

    2015-01-01

    Synopsis Externalizing problems are multi-determined and related to individual, family, peer, school, and community risk factors. Multisystemic therapy (MST) was originally developed to address these risk factors among youth with serious conduct problems who were at-risk for out-of-home placement. Several decades of research has established MST as an evidence-based intervention for adolescents with serious clinical problems, including serious offending, delinquency, substance abuse, and parental physical abuse and neglect. Further, research points to the importance of maintaining high treatment fidelity through systematic quality assurance procedures to replicate positive clinical outcomes. This paper presents an overview of the clinical procedures and evidence base of MST for externalizing problems as well as two adaptations: MST for Substance Abuse and MST for Child Abuse and Neglect. PMID:26092742

  8. Reverse shoulder arthroplasty for the management of proximal humerus fractures.

    PubMed

    Jobin, Charles M; Galdi, Balazs; Anakwenze, Oke A; Ahmad, Christopher S; Levine, William N

    2015-03-01

    The use of reverse shoulder arthroplasty is becoming increasingly popular for the treatment of complex three- and four-part proximal humerus fractures in the elderly compared with the often unpredictable and poor outcomes provided by open reduction and internal fixation and by hemiarthroplasty. Inferior results with plate osteosynthesis are often a result of complications of humeral head osteonecrosis, loss of fixation, and screw penetration through the humeral head, whereas major concerns with hemiarthroplasty are tuberosity resorption, malunion, and nonunion resulting in pseudoparalysis. Comparative studies support the use of reverse shoulder arthroplasty in elderly patients with complex proximal humerus fractures because the functional outcomes and relief of pain are reliably improved. Repair and union of the greater tuberosity fragment during reverse shoulder arthroplasty demonstrates improved external rotation, clinical outcomes, and patient satisfaction compared with outcomes after tuberosity resection, nonunion, or resorption. Satisfactory results can be obtained with careful preoperative planning and attention to technical details.

  9. Optimal timing for nasal fracture manipulation - is a two week target really necessary? A single-centre retrospective analysis of 50 patients.

    PubMed

    Perkins, V; Vijendren, A; Egan, M; McRae, D

    2017-04-04

    Nasal bone fractures represent the most common isolated facial fracture and are involved in as many as 50% of facial fractures ((1)) . Its relative prominence in the centre of the face as well as its relatively thin, fragile structures makes it particularly susceptible to injury. Acute management is centred on restoring an aesthetically acceptable external nose with minimal airflow limitation. Conventional UK management typically involves assessment 5-7 days following injury, followed by closed reduction within two weeks, to avoid problems associated with fracture healing and bone remodelling ((2)) . This article is protected by copyright. All rights reserved.

  10. Incorporating Discrete Irregular Fracture Zone Networks into 3D Paleohydrogeologic Simulations

    NASA Astrophysics Data System (ADS)

    Normani, S. D.

    2015-12-01

    Dual continuum computational models which include both porous media and discrete fracture zones are valuable tools in assessing groundwater migration and pathways in fractured rock systems. Fracture generation models can produce stochastic realizations of fracture networks which honor geological structures and fracture propagation behaviors. Surface lineament traces can be propagated to depth based on fracture zone statistics to produce representations of geological structures in rock. The generated discrete, complex and irregular fracture zone networks, represented as a triangulated mesh, are embedded using orthogonal quadrilateral elements within a three-dimensional hexahedral finite element mesh. A detailed coupled density-dependent paleohydrogeologic groundwater analysis of a hypothetical 104 km2 portion of the Canadian Shield has been conducted using the discrete-fracture dual continuum finite element model FRAC3DVS to investigate the characterization of large-scale fracture zone networks on groundwater and tracer movement during a 120,000 year paleoclimate cycle. Permeability reduction due to permafrost was also applied. Time series data for the depth of permafrost, along with ice thickness and lake depth, were provided by the University of Toronto (UofT) Glacial Systems Model. The crystalline rock between fracture zones was assigned properties characteristic of those reported for the Canadian Shield. Total dissolved solids concentrations of 300 g/L are encountered at depth. Surface water features and a Digital Elevation Model (DEM) were used in a GIS framework to define the watershed boundaries at surface water divides and to populate the finite element mesh. This work will illustrate the long-term evolution and stability of the geosphere and groundwater systems to external perturbations caused by glaciation through the use of performance measures such as Mean Life Expectancy and the migration of a unit tracer to depth over a paleoclimate cycle.

  11. Computed tomography of stress fracture

    SciTech Connect

    Murcia, M.; Brennan, R.E.; Edeiken, J.

    1982-06-01

    An athletic young female developed gradual onset of pain in the right leg. Plain radiographs demonstrated solid periosteal reaction in the tibia compatible with stress fracture. She stopped sport activites but her pain continued. Follow-up radiographs of the tibia revealed changes suspicious for osteoid osteoma. Computed tomography (CT) scan demonstrated periosteal reaction, but in addition, lucent fracture lines in the tibial cortex were evident. CT obviated the need for more invasive diagnostic procedures in this patient. In selected cases CT may be useful to confirm the diagnosis of stress fracture when plain radiographic or routine tomographic studies are not diagnostic.

  12. Successful treatment of nonunion with an Ilizarov ring fixator after ankle fracture for Charcot arthropathy: a case report

    PubMed Central

    2014-01-01

    Background Ankle fractures in patients with diabetes mellitus have long been recognized as a challenge to orthopedic surgeons. Nonunion and lengthy wound healing in high-risk patients with diabetes, particularly patients with peripheral arterial disease and renal failure, occur secondary to several clinical conditions and are often fraught with complications. Whether diabetic ankle fractures are best treated noninvasively or surgically is controversial. Case presentation A 53-year-old Japanese man fractured his right ankle. The fractured ankle was treated nonsurgically with a plaster cast. Although he remained non-weight-bearing for 3 months, radiography at 3 months showed nonunion. The nonunion was treated by Ilizarov external fixation of the ankle. The external fixator was removed 99 days postoperatively, at which time the patient exhibited anatomical and functional recovery and was able to walk without severe complications. Conclusion In patients with diabetes mellitus, severe nonunion of ankle fractures with Charcot arthropathy in which the fracture fragment diameter is very small and the use of internal fixation is difficult is a clinical challenge. Ilizarov external fixation allows suitable fixation to be achieved using multiple Ilizarov wires. PMID:25103697

  13. Apical phosphatidylserine externalization in auditory hair cells.

    PubMed

    Shi, Xiaorui; Gillespie, Peter G; Nuttall, Alfred L

    2007-01-01

    In hair cells of the inner ear, phosphatidylserine (PS), detected with fluorescent annexin V labeling, was rapidly exposed on the external leaflet of apical plasma membranes upon dissection of the organ of Corti. PS externalization was unchanged by caspase inhibition, suggesting that externalization did not portend apoptosis or necrosis. Consistent with that conclusion, mitochondrial membrane potential and hair-cell nuclear structure remained normal during externalization. PS externalization was triggered by forskolin, which raises cAMP, and blocked by inhibitors of adenylyl cyclase. Blocking Na(+) influx by inhibiting the mechanoelectrical transduction channels and P2X ATP channels also inhibited external PS externalization. Diminished PS externalization was also seen in cells exposed to LY 294002, which blocks membrane recycling in hair cells by inhibiting phosphatidylinositol 3-kinase. These results indicate that PS exposure on the external leaflet, presumably requiring vesicular transport, results from elevation of intracellular cAMP, which can be triggered by Na(+) entry into hair cells.

  14. [Lifestyle-related disease and fracture risk].

    PubMed

    Fujiwara, Saeko

    2011-05-01

    Meta analysis of fracture risk in diabetes indicates that the risk of proximal femoral fracture in type-2 diabetes is increased 1.4-1.7 times. It is well known that increased fracture risk is observed in serious kidney disease. However, it has recently been reported that increased fracture risk is also observed in the early stages of chronic kidney disease (CKD) . The risk of proximal femoral fracture increases in early stages after stroke, but gradually decreases in subsequent stages. Some reports indicate decreased fracture risk in metabolic syndrome and hyperlipidemia and increased fracture risk in hypertension, arterial calcification and ischemic heart disease, while other reports indicate contradictory results.

  15. Complications of Pediatric Foot and Ankle Fractures.

    PubMed

    Denning, Jaime R

    2017-01-01

    Ankle fractures account for 5% and foot fractures account for approximately 8% of fractures in children. Some complications are evident early in the treatment or natural history of foot and ankle fractures. Other complications do not become apparent until weeks, months, or years after the original fracture. The incidence of long-term sequelae like posttraumatic arthritis from childhood foot and ankle fractures is poorly studied because decades or lifelong follow-up has frequently not been accomplished. This article discusses a variety of complications associated with foot and ankle fractures in children or the treatment of these injuries.

  16. A revisit to high-rate mode-II fracture characterization of composites with Kolsky bar techniques.

    SciTech Connect

    Lu, Wei-Yang; Song, Bo; Jin, Huiqing

    2010-03-01

    Nowadays composite materials have been extensively utilized in many military and industrial applications. For example, the newest Boeing 787 uses 50% composite (mostly carbon fiber reinforced plastic) in production. However, the weak delamination strength of fiber reinforced composites, when subjected to external impact such as ballistic impact, has been always potential serious threats to the safety of passengers. Dynamic fracture toughness is a critical indicator of the performance from delamination in such impact events. Quasi-static experimental techniques for fracture toughness have been well developed. For example, end notched flexure (ENF) technique, which is illustrated in Fig. 1, has become a typical method to determined mode-II fracture toughness for composites under quasi-static loading conditions. However, dynamic fracture characterization of composites has been challenging. This has resulted in conflictive and confusing conclusions in regard to strain rate effects on fracture toughness of composites.

  17. Fracture in macro-molecules

    NASA Technical Reports Server (NTRS)

    Devries, K. L.

    1976-01-01

    Techniques available for the observation of molecular bond rupture during fracture of polymers are briefly outlined. Additional pertinent information can also often be inferred from microscopic and macroscopic measures.

  18. Principles of Hand Fracture Management

    PubMed Central

    Haughton, DN; Jordan, D; Malahias, M; Hindocha, S; Khan, W

    2012-01-01

    The hand is essential in humans for physical manipulation of their surrounding environment. Allowing the ability to grasp, and differentiated from other animals by an opposing thumb, the main functions include both fine and gross motor skills as well as being a key tool for sensing and understanding the immediate surroundings of their owner. Hand fractures are the most common fractures presenting at both accident and emergency and within orthopaedic clinics. Appropriate evaluation at first presentation, as well as during their management, can significantly prevent both morbidity and disability to a patient. These decisions are dependant on a wide range of factors including age, hand dominance, occupation and co-morbidities. A fracture is best described as a soft tissue injury with an associated bony injury. Despite this being the case, this paper intends to deal mainly with the bone injury and aims to discuss both the timing, as well as the methods available, of hand fracture management. PMID:22423303

  19. Microstructural effects in foam fracture

    NASA Astrophysics Data System (ADS)

    Stewart, Peter; Davis, Stephen; Hilgenfeldt, Sascha

    2015-11-01

    We examine the fracture of a quasi two-dimensional aqueous foam under an applied driving pressure, using a network modelling approach developed for metallic foams by Stewart & Davis (J. Rheol., vol. 56, 2012, p. 543). In agreement with experiments, we observe two distinct mechanisms of failure analogous to those observed in a crystalline solid: a slow ductile mode when the driving pressure is applied slowly, where the void propagates as bubbles interchange neighbours through the T1 process, and a rapid brittle mode for faster application of pressures, where the void advances by successive rupture of liquid films driven by Rayleigh-Taylor instability. The simulations allow detailed insight into the mechanics of the fracturing medium and the role of its microstructure. In particular, we examine the stress distribution around the crack tip and investigate how brittle fracture localizes into a single line of breakages. We also confirm that pre-existing microstructural defects can alter the course of fracture.

  20. Diesel Fuels Hydraulic Fracturing (DFHF)

    EPA Pesticide Factsheets

    This webpage provides information on how hydraulic fracturing is regulated by the Underground Injection Control Program. It includes information about what owners and operators need to do to be in compliance and guidance for EPA Class II permit writers.

  1. Fetal akinesia and multiple perinatal fractures.

    PubMed

    Chen, H; Blackburn, W R; Wertelecki, W

    1995-02-13

    Two newborn infants with fetal akinesia sequence were noted to have multiple perinatal fractures of the long bones. The radiographic manifestations are characterized by gracile ribs, thin long bones, and multiple diaphyseal fractures. Consistent histopathologic changes of bone are irregular with focal areas of extreme diaphyseal thinning, thin and long marrow spicules, and with or without callous formation at fracture sites. Pathogenic mechanisms of bone fractures in fetal akinesia sequence and the differential diagnoses of congenital/perinatal bone fractures are discussed.

  2. International Space Station External Contamination Status

    NASA Technical Reports Server (NTRS)

    Mikatarian, Ron; Soares, Carlos

    2000-01-01

    PResentation slides examine external contamination requirements; International Space Station (ISS) external contamination sources; ISS external contamination sensitive surfaces; external contamination control; external contamination control for pre-launch verification; flight experiments and observations; the Space Shuttle Orbiter waste water dump, materials outgassing, active vacuum vents; example of molecular column density profile, modeling and analysis tools; sources of outgassing induced contamination analyzed to date, quiescent sources, observations on optical degradation due to induced external contamination in LEO; examples of typical contaminant and depth profiles; and status of the ISS system, material outgassing, thruster plumes, and optical degradation.

  3. Estimating the fracture density of small-scale vertical fractures when large-scale vertical fractures are present

    NASA Astrophysics Data System (ADS)

    Liu, Yuwei; Dong, Ning; Fehler, Mike; Fang, Xinding; Liu, Xiwu

    2015-06-01

    Fractures in reservoirs significantly affect reservoir flow properties in subsequent years, which means that fracture characteristics such as preferred orientation, crack density or fracture compliance, what filling is in the fractures and so on are of great importance for reservoir development. When fractures are vertical, aligned and their dimensions are small relative to the seismic wavelength, the medium can be considered to be an equivalent horizontal transverse isotropic (HTI) medium. However, geophysical data acquired over naturally fractured reservoirs often reveal the presence of multiple fracture sets. We investigate a case where there are two vertical sets of fractures having differing length scales. One fracture set has length scale that is much smaller than the seismic wavelength but the other has length scale that is similar to the seismic wavelength. We use synthetic data to investigate the ability to infer the properties of the small-scale fractures in the presence of the large-scale fracture set. We invert for the Thomsen-type anisotropic coefficients of the small-scale fracture set by using the difference of the P wave amplitudes at two azimuths, which makes the inversion convex. Then we investigate the influence of the presence of the large-scale fractures on our ability to infer the properties of the small-scale fracture set. Surprisingly, we find that we can reliably infer the fracture density of the small-scale fractures even in the presence of large-scale fractures having significant compliance values. Although the inversion results for Thomsen-type anisotropic coefficients of small-scale fractures for one model are not good enough to figure out whether it is gas-filled or fluid-filled, we can find a big change of Thomsen-type anisotropic coefficient {{\\varepsilon}(V)} between the models in which small-scale fractures are filled with gas and fluid.

  4. Keyhole Fracture of the Skull

    DTIC Science & Technology

    2008-12-01

    gunshot wounds to the skull and direction of fire. J Forensic Sci 1982;27:555-66. 3. Berryman HE, Gunther WM. Keyhole defect production in tubular bone.J...Keyhole Fracture of the Skull Radiology Corner Keyhole Fracture of the Skull Guarantor...abbreviated answer in the December 2008 issue. 1 The authors present the case of a soldier wounded in Iraq with a gunshot wound to the skull

  5. Rehabilitative strategies following hand fractures.

    PubMed

    Hays, Peyton L; Rozental, Tamara D

    2013-11-01

    The importance of rehabilitation in the management of hand fractures cannot be overstated. The breadth of rehabilitative strategies ranges from heat and range-of-motion exercises to more complex splinting and tendon gliding modalities. The goals, however, are clear: control pain; limit soft tissue swelling; provide support for fracture healing; restore motion, strength, and function; and enable the return to work and daily activities.

  6. Fracturing fluid characterization facility (FFCF)

    SciTech Connect

    Evans, R.D.; Roegiers, J.C.; Fagan, J.

    1993-12-31

    The Fracturing Fluid Characterization Facility project has as its main focus the design, fabrication, and construction of a high pressure simulator (HPS) and a low pressure simulator (LPS) to be used to experimentally investigate the rheological properties and transport characteristics of proppant laden fracturing fluids. A discussion of each apparatus is provided as well as the auxiliary equipment, and data acquisition and control systems associated with the simulators.

  7. Seismic characteristics of tensile fracture growth induced by hydraulic fracturing

    NASA Astrophysics Data System (ADS)

    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

  8. Fracture of composite orthotropic plates for materials type 2

    NASA Technical Reports Server (NTRS)

    Delale, F.

    1976-01-01

    The fracture problem of laminated plates which consist of orthotropic layers is considered. Symmetrical cracks are located normal to the bimaterial interfaces. The external loads are applied away from the crack region. Three cases are considered: (a) the case of internal cracks; (b) the case of broken laminates; and (c) case of a crack crossing the interface. A general formulation of the problem is given for plane strain and generalized plane stress cases. The singular behavior of stresses at the crack tips and at the interfaces is studied. In each case the stress intensity factors are computed for various crack geometries.

  9. Fracture behaviour of polycrystalline tungsten

    NASA Astrophysics Data System (ADS)

    Gaganidze, Ermile; Rupp, Daniel; Aktaa, Jarir

    2014-03-01

    Fracture behaviour of round blank polycrystalline tungsten was studied by means of three point bending Fracture-Mechanical (FM) tests at temperatures between RT and 1000 °C and under high vacuum. To study the influence of the anisotropic microstructure on the fracture toughness (FT) and ductile-to-brittle transition (DBT) the specimens were extracted in three different, i.e. longitudinal, radial and circumferential orientations. The FM tests yielded distinctive fracture behaviour for each specimen orientation. The crack propagation was predominantly intergranular for longitudinal orientation up to 600 °C, whereas transgranular cleavage was observed at low test temperatures for radial and circumferentially oriented specimens. At intermediate test temperatures the change of the fracture mode took place for radial and circumferential orientations. Above 800 °C all three specimen types showed large ductile deformation without noticeable crack advancement. For longitudinal specimens the influence of the loading rate on the FT and DBT was studied in the loading rate range between 0.06 and 18 MPa m1/2/s. Though an increase of the FT was observed for the lowest loading rate, no resolvable dependence of the DBT on the loading rate was found partly due to loss of FT validity. A Master Curve approach is proposed to describe FT vs. test temperature data on polycrystalline tungsten. Fracture safe design space was identified by analysis compiled FT data.

  10. Tracer mixing at fracture intersections

    SciTech Connect

    Li, Guomin

    2001-02-10

    Discrete network models are one of the approaches used to simulate a dissolved contaminant, which is usually represented as a tracer in modeling studies, in fractured rocks. The discrete models include large numbers of individual fractures within the network structure, with flow and transport described on the scale of an individual fracture. Numerical simulations for the mixing characteristics and transfer probabilities of a tracer through a fracture intersection are performed for this study. A random-walk, particle-tracking model is applied to simulate tracer transport in fracture intersections by moving particles through space using individual advective and diffusive steps. The simulation results are compared with existing numerical and analytical solutions for a continuous intersection over a wide range of Peclet numbers. This study attempts to characterize the relative concentration at the outflow branches for a continuous intersection with different flow fields. The simulation results demonstrate that the mixing characteristics at the fracture intersections are a function not only of the Peclet number but also of the flow field pattern.

  11. Estimating location without external cues.

    PubMed

    Cheung, Allen

    2014-10-01

    The ability to determine one's location is fundamental to spatial navigation. Here, it is shown that localization is theoretically possible without the use of external cues, and without knowledge of initial position or orientation. With only error-prone self-motion estimates as input, a fully disoriented agent can, in principle, determine its location in familiar spaces with 1-fold rotational symmetry. Surprisingly, localization does not require the sensing of any external cue, including the boundary. The combination of self-motion estimates and an internal map of the arena provide enough information for localization. This stands in conflict with the supposition that 2D arenas are analogous to open fields. Using a rodent error model, it is shown that the localization performance which can be achieved is enough to initiate and maintain stable firing patterns like those of grid cells, starting from full disorientation. Successful localization was achieved when the rotational asymmetry was due to the external boundary, an interior barrier or a void space within an arena. Optimal localization performance was found to depend on arena shape, arena size, local and global rotational asymmetry, and the structure of the path taken during localization. Since allothetic cues including visual and boundary contact cues were not present, localization necessarily relied on the fusion of idiothetic self-motion cues and memory of the boundary. Implications for spatial navigation mechanisms are discussed, including possible relationships with place field overdispersion and hippocampal reverse replay. Based on these results, experiments are suggested to identify if and where information fusion occurs in the mammalian spatial memory system.

  12. Sarcopenia and fragility fractures.

    PubMed

    Cederholm, T; Cruz-Jentoft, A J; Maggi, S

    2013-02-01

    Sarcopenia, a reduction in muscle mass and muscle function, is considered one of the hallmarks of the aging process. Current views consider sarcopenia as the consequence of multiple medical, behavioural and environmental factors that characterize aged individuals. Likewise bone fragility is known to depend on several pathogenetic mechanisms leading to bone mass loss and reduction of bone strength. Muscle weakness, fear of falls, falls and subsequent fractures are associated to concurrent sarcopenia and osteoporosis and lead to restricted mobility, loss of autonomy and reduced life expectancy. The skeletal and the muscular organ systems are tightly intertwined: the strongest mechanical forces applied to bones are, indeed, those created by muscle contractions that condition bone density, strength, and microarchitecture. Not surprising, therefore, the decrease in muscle strength leads to lower bone strength. The degenerative processes leading to osteoporosis and sarcopenia show many common pathogenic pathways, like the sensitivity to reduced anabolic hormone secretion, increased inflammatory cytokine activity and reduced physical activity. Thus they may also respond to the same kind of treatments. Basic is life-style interventions related to exercise and nutrition. Sufficient vitamin D levels are of importance for both bone and muscle, primarily provided by sun exposure at younger age, and by supplementation at older age. Resistance training several times per week is crucial, and to be effective adequate access to energy and proteins is necessary.

  13. Fracturing And Liquid CONvection

    SciTech Connect

    2012-02-29

    FALCON has been developed to enable simulation of the tightly coupled fluid-rock behavior in hydrothermal and engineered geothermal system (EGS) reservoirs, targeting the dynamics of fracture stimulation, fluid flow, rock deformation, and heat transport in a single integrated code, with the ultimate goal of providing a tool that can be used to test the viability of EGS in the United States and worldwide. Reliable reservoir performance predictions of EGS systems require accurate and robust modeling for the coupled thermal-hydrological-mechanical processes. Conventionally, these types of problems are solved using operator-splitting methods, usually by coupling a subsurface flow and heat transport simulator with a solid mechanics simulator via input files. FALCON eliminates the need for using operator-splitting methods to simulate these systems, and the scalability of the underlying MOOSE architecture allows for simulating these tightly coupled processes at the reservoir scale, allowing for examination of the system as a whole (something the operator-splitting methodologies generally cannot do).

  14. Water fluoridation and osteoporotic fracture.

    PubMed

    Hillier, S; Inskip, H; Coggon, D; Cooper, C

    1996-09-01

    Osteoporotic fractures constitute a major public health problem. These fractures typically occur at the hip, spine and distal forearm. Their pathogenesis is heterogeneous, with contributions from both bone strength and trauma. Water fluoridation has been widely proposed for its dental health benefits, but concerns have been raised about the balance of skeletal risks and benefits of this measure. Fluoride has potent effects on bone cell function, bone structure and bone strength. These effects are mediated by the incorporation of fluoride ions in bone crystals to form fluoroapatite, and through an increase in osteoblast activity. It is believed that a minimum serum fluoride level of 100 ng/ml must be achieved before osteoblasts will be stimulated. Serum levels associated with drinking water fluoridated to 1 ppm are usually several times lower than this value, but may reach this threshold at concentrations of 4 ppm in the drinking water. Animal studies suggest no effect of low-level (0-3 ppm) fluoride intake on bone strength, but a possible decrease at higher levels. Sodium fluoride has been used to treat established osteoporosis for nearly 30 years. Recent trials of this agent, prescribed at high doses, have suggested that despite a marked increase in bone mineral density, there is no concomitant reduction in vertebral fracture incidence. Furthermore, the increase in bone density at the lumbar spine may be achieved at the expense of bone mineral in the peripheral cortical skeleton. As a consequence, high dose sodium fluoride (80 mg daily) is not currently used to treat osteoporosis. At lower doses, recent trials have suggested a beneficial effect on both bone density and fracture. The majority of epidemiological evidence regarding the effect of fluoridated drinking water on hip fracture incidence is based on ecological comparisons. Although one Finnish study suggested that hip fracture rates in a town with fluoridated water were lower than those in a matching town

  15. Fracturing from highly deviated and horizontal wells: Numerical analysis of non-planar fracture propagation

    SciTech Connect

    Olson, J.E.

    1995-12-31

    Fracturing from horizontal and highly deviated wells can often result in complex, non-planar fracture geometry. A two-dimensional model was developed to analyze the effects of non-planar fracture propagation for different in situ boundary conditions and hydraulic fracturing parameters. Numerical simulations show that curving fracture geometry reduces created fracture length compared to a planar fracture and causes a fracture width restriction at the wellbore. Reduction in fracture length can reduce expected well stimulation effects and jeopardize well economics. Near-wellbore width restrictions increase fracture treating pressure and may cause wellbore screen-out during the proppant stages of a fracturing treatment. The negative impact of non-planar geometry can be mitigated with short perforated intervals, high viscosity fracturing fluids, proper wellbore alignment and pre-pad proppant slugs for near-wellbore erosion.

  16. External tank aft cargo carrier

    NASA Technical Reports Server (NTRS)

    Mobley, T. B.

    1984-01-01

    The External Tank (ET) Aft Cargo Carrier (ACC) is a low cost, low risk augmentation of the Space Transportation System (STS). It almost doubles the cargo volume of the STS while minimally impacting other STS elements (orbiter, ET and solid rocket boosters SRBs, launch facilities and STS operations. In addition to increasing the potential volume of cargo carried on a Shuttle launch, the ACC provides the following additional benefits: (1) Increased STS competitiveness for payloads; (2) Increased cargo manifest flexibility; (3) Increased spacecraft design options; (4) Alternate manifesting for special payloads; and (5) Future space platform/station design options.

  17. Externally blown flap impingement noise.

    NASA Technical Reports Server (NTRS)

    Putnam, T. W.; Lasagna, P. L.

    1972-01-01

    An investigation of externally blown flap impingement noise was conducted using a full-scale turbofan engine and aircraft wing. The noise produced with a daisy nozzle installed on the engine exhaust system was greater than that produced by a conical nozzle at the same thrust. The daisy nozzle caused the jet velocity to decay about 35 percent at the flap. The presence of the wing next to the conical nozzle increased the noise, as did increasing the flap deflection. Compared with the conical nozzle, the daisy nozzle produced slightly less noise at a flap deflection of 60 deg but produced more noise at the lower flap deflections tested.

  18. Acute incarcerated external abdominal hernia

    PubMed Central

    Yang, Xue-Fei

    2014-01-01

    External abdominal hernia occurs when abdominal organs or tissues leave their normal anatomic site and protrude outside the skin through the congenital or acquired weakness, defects or holes on the abdominal wall, including inguinal hernia, umbilical hernia, femoral hernia and so on. Acute incarcerated hernia is a common surgical emergency. With advances in minimally invasive devices and techniques, the diagnosis and treatment have witnessed major changes, such as the use of laparoscopic surgery in some cases to achieve minimally invasive treatment. However, strict adherence to the indications and contraindications is still required. PMID:25489584

  19. Concomitant and previous osteoporotic vertebral fractures

    PubMed Central

    Lenski, Markus; Büser, Natalie; Scherer, Michael

    2017-01-01

    Background and purpose Patients with osteoporosis who present with an acute onset of back pain often have multiple fractures on plain radiographs. Differentiation of an acute osteoporotic vertebral fracture (AOVF) from previous fractures is difficult. The aim of this study was to investigate the incidence of concomitant AOVFs and previous OVFs in patients with symptomatic AOVFs, and to identify risk factors for concomitant AOVFs. Patients and methods This was a prospective epidemiological study based on the Registry of Pathological Osteoporotic Vertebral Fractures (REPAPORA) with 1,005 patients and 2,874 osteoporotic vertebral fractures, which has been running since February 1, 2006. Concomitant fractures are defined as at least 2 acute short-tau inversion recovery (STIR-) positive vertebral fractures that happen concomitantly. A previous fracture is a STIR-negative fracture at the time of initial diagnostics. Logistic regression was used to examine the influence of various variables on the incidence of concomitant fractures. Results More than 99% of osteoporotic vertebral fractures occurred in the thoracic and lumbar spine. The incidence of concomitant fractures at the time of first patient contact was 26% and that of previous fractures was 60%. The odds ratio (OR) for concomitant fractures decreased with a higher number of previous fractures (OR =0.86; p = 0.03) and higher dual-energy X-ray absorptiometry T-score (OR =0.72; p = 0.003). Interpretation Concomitant and previous osteoporotic vertebral fractures are common. Risk factors for concomitant fractures are a low T-score and a low number of previous vertebral fractures in cases of osteoporotic vertebral fracture. An MRI scan of the the complete thoracic and lumbar spine with STIR sequence reduces the risk of under-diagnosis and under-treatment. PMID:28056595

  20. Easing the Burden of External Reporting

    ERIC Educational Resources Information Center

    LoGrasso, Marc F.

    2015-01-01

    In this chapter, the author presents suggestions for improving the effectiveness of external reporting while minimizing burden. Recommendations include repurposing existing internal reports to address the needs of external reports.

  1. 14 CFR 27.865 - External loads.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... authorized external load as demonstrated under § 27.25 and this section. (f) The fatigue evaluation of § 27.... For rotorcraft-load combinations to be used for human external cargo, the fatigue evaluation of §...

  2. 14 CFR 27.865 - External loads.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... authorized external load as demonstrated under § 27.25 and this section. (f) The fatigue evaluation of § 27.... For rotorcraft-load combinations to be used for human external cargo, the fatigue evaluation of §...

  3. Optimal scaling in ductile fracture

    NASA Astrophysics Data System (ADS)

    Fokoua Djodom, Landry

    This work is concerned with the derivation of optimal scaling laws, in the sense of matching lower and upper bounds on the energy, for a solid undergoing ductile fracture. The specific problem considered concerns a material sample in the form of an infinite slab of finite thickness subjected to prescribed opening displacements on its two surfaces. The solid is assumed to obey deformation-theory of plasticity and, in order to further simplify the analysis, we assume isotropic rigid-plastic deformations with zero plastic spin. When hardening exponents are given values consistent with observation, the energy is found to exhibit sublinear growth. We regularize the energy through the addition of nonlocal energy terms of the strain-gradient plasticity type. This nonlocal regularization has the effect of introducing an intrinsic length scale into the energy. We also put forth a physical argument that identifies the intrinsic length and suggests a linear growth of the nonlocal energy. Under these assumptions, ductile fracture emerges as the net result of two competing effects: whereas the sublinear growth of the local energy promotes localization of deformation to failure planes, the nonlocal regularization stabilizes this process, thus resulting in an orderly progression towards failure and a well-defined specific fracture energy. The optimal scaling laws derived here show that ductile fracture results from localization of deformations to void sheets, and that it requires a well-defined energy per unit fracture area. In particular, fractal modes of fracture are ruled out under the assumptions of the analysis. The optimal scaling laws additionally show that ductile fracture is cohesive in nature, i.e., it obeys a well-defined relation between tractions and opening displacements. Finally, the scaling laws supply a link between micromechanical properties and macroscopic fracture properties. In particular, they reveal the relative roles that surface energy and microplasticity

  4. Modelling the graphite fracture mechanisms

    SciTech Connect

    Jacquemoud, C.; Marie, S.; Nedelec, M.

    2012-07-01

    In order to define a design criterion for graphite components, it is important to identify the physical phenomena responsible for the graphite fracture, to include them in a more effective modelling. In a first step, a large panel of experiments have been realised in order to build up an important database; results of tensile tests, 3 and 4 point bending tests on smooth and notched specimens have been analysed and have demonstrated an important geometry related effects on the behavior up to fracture. Then, first simulations with an elastic or an elastoplastic bilinear constitutive law have not made it possible to simulate the experimental fracture stress variations with the specimen geometry, the fracture mechanisms of the graphite being at the microstructural scale. That is the reason why a specific F.E. model of the graphite structure has been developed in which every graphite grain has been meshed independently, the crack initiation along the basal plane of the particles as well as the crack propagation and coalescence have been modelled too. This specific model has been used to test two different approaches for fracture initiation: a critical stress criterion and two criteria of fracture mechanic type. They are all based on crystallographic considerations as a global critical stress criterion gave unsatisfactory results. The criteria of fracture mechanic type being extremely unstable and unable to represent the graphite global behaviour up to the final collapse, the critical stress criterion has been preferred to predict the results of the large range of available experiments, on both smooth and notched specimens. In so doing, the experimental observations have been correctly simulated: the geometry related effects on the experimental fracture stress dispersion, the specimen volume effects on the macroscopic fracture stress and the crack propagation at a constant stress intensity factor. In addition, the parameters of the criterion have been related to

  5. Clinician approach to diagnosis of stress fractures including bisphosphonate-associated fractures.

    PubMed

    McKenna, M J; Heffernan, E; Hurson, C; McKiernan, F E

    2014-02-01

    Stress fractures are repetitive strain injuries that occur in normal bones and in abnormal bones. Stress fractures share many features in common but differences depend on the status of the underlying bone. This review article for clinicians addresses aspects about stress fractures with particular respect to fatigue fractures, Looser zones of osteomalacia, atypical Looser zones, atypical femoral fractures associated with bisphosphonate therapy and stress fractures in Paget's disease of bone.

  6. Childhood Externalizing Behavior: Theory and Implications

    PubMed Central

    Liu, Jianghong

    2006-01-01

    TOPIC Childhood externalizing behavior PURPOSE To analyze the construct of externalizing behavior (aggression, delinquency, and hyperactivity), illustrate the biosocial model of childhood externalizing, and draw clinical implications for nursing research and practice. SOURCES A review of the literature based on psychological, psychiatric, and nursing journals. CONCLUSIONS A better understanding of childhood externalizing behavior problems and the risk factors underlying them are essential to prevent them. The employment of an integrative biosocial perspective is argued to be important in understanding this behavior. PMID:15535385

  7. Neural correlates of sound externalization.

    PubMed

    Callan, Akiko; Callan, Daniel E; Ando, Hiroshi

    2013-02-01

    When we listen to sounds through headphones without utilizing special transforms, sound sources seem to be located inside our heads. The sound sources are said to be lateralized to one side or the other to varying degree. This internal lateralization is different than sound source localization in the natural environment in which the sound is localized distal to the head. We used fMRI to investigate difference in neural responses between lateralization and localization. Individualized binaural recordings were used as externalized auditory stimuli and stereo recordings were used as internalized auditory stimuli. Brain activity was measured while 14 participants performed an active auditory localization task and while 12 participants performed a stimulus type identification task. Irrespective of the task condition, we observed enhanced activity in the bilateral posterior temporal gyri (pSTG) for the externalized stimuli relative to the internalized stimuli. Region of interest analysis indicated that both left and right pSTG were more sensitive to sound sources in contra- than ipsilateral hemifields. Moreover, greater back than front activity was also found in the left pSTG. Compared to impoverished spatial auditory stimuli, realistic spatial auditory stimuli enhance neural responses in the pSTG. This may be why we could observe contralateral hemifield preference in bilateral pSTG that many previous studies have failed to observe. Overall, the results indicate the importance of using ecologically valid stimuli for investigating neural processes in human cortex.

  8. An Uncommon Combination of Fractures around the Elbow: Capitellum Fracture Associated with Radial Head Fracture

    PubMed Central

    Walid, Osman; Meriem, Braiki; Zeineb, Alaya; Nader, Naouar; Mohamed, Ben Ayeche

    2016-01-01

    Introduction: The coexistence of fractures of capitulum humeri and radial head in the elbow joint is a rare entity. Case Report: A 30-year-old woman was admitted to our hospital after having sustained a fall on her outstretched right arm. She complained of pain, swelling, and restriction of motion of the right elbow joint. Anteroposterior and lateral radiographs revealed displaced fractures in the capitellum and the radial head. The patient was operated. Fractures were exposed through a lateral (Kocher) incision. Fracture was reduced, and fixation was performed with 2 AO compression screw. Two fragments of radial head fracture were also reduced and fixed with AO compression screw. Clinical and radiographic outcomes were excellent at the end of a 5-year follow-up. Conclusion: These fractures occurred following a fall on the palm with outstretched arm. The success of the treatment depends greatly on surgical approach and suitable technique which requires comprehensive knowledge of detailed anatomy and biomechanics of the elbow. PMID:28164067

  9. Effect of retention design of artificial teeth and implant-supported titanium CAD-CAM structures on fracture resistance

    PubMed Central

    Ladetzki, Kristin; Mateos-Palacios, Rocío; Pascual-Moscardó, Agustín

    2016-01-01

    Background For implant-supported hybrid prostheses, high mastication forces and reduced acrylic resin thickness over a metal substructure often cause failures arising from tooth or resin fractures. To assay fracture resistance of artificial teeth and resin in implant-supported hybrid prostheses in relation to the titanium structure and retention design supporting teeth. Material and Methods 40 specimens bearing incisors were divided into four groups according to the titanium structure supporting the teeth and the type of load force applied: Group I (Control; n=10): Application of static loading to ten incisors set over a metal structure with internal retention. Group II (Control; n=10): Application of static loading to ten incisors set over a metal structure with external retention. The remaining study specimens (n=20) were subjected to 120,000 masticatory and thermal cycles in a chewing simulator. Afterwards, static loading was applied until the point of fracture using an Instron machine. Group III (Study; n=10): Application of dynamic and static loading to ten incisors set over a metal structure with internal retention. Group IV (Study; n=10): Application of dynamic and static loading to ten incisors set over a metal structure with external retention. Data obtained for the four groups was analyzed and compared, determining the type of fracture (cohesive or adhesive) using a reflected light microscope. Results Statistical analysis confirmed that there were significant differences in fracture resistance between the four groups. External retention was found to have more fracture resistance than the internal retention. Conclusions Hybrid prostheses with titanium substructures and external retention obtained significantly better results than samples with internal retention. Key words:Chewing simulator, thermocycler, fatigue, implant-supported hybrid prosthesis, acrylic teeth, fracture, metal structure design. PMID:27034748

  10. Patient-reported outcome following nonsurgical management of type II odontoid process fractures in adults

    PubMed Central

    Fam, Maged D; Zeineddine, Hussein A; Nassir, Rafiq Muhammed; Bhatt, Pragnesh; Kamel, Mahmoud H

    2017-01-01

    Background: Transverse (type II) odontoid process fracture is among the most commonly encountered cervical spine fractures. Nonsurgical management through external immobilization is occasionally preferred to surgical management but is criticized for its higher rates of failure and lower patient satisfaction. Our aim is to analyze patient-reported outcomes in patients who underwent nonsurgical treatment for type II odontoid fractures. Methods: We identified patients >18-year-old who underwent external immobilization as a treatment for isolated type II odontoid fracture between 2007 and 2012. We collected demographic parameters, clinical presentation, mode of injury, imaging studies and modality and duration of treatment (soft collar, halo-vest, or both). Patients were contacted by telephone to participate in a 15-min survey addressing their recovery including their subjective rate of return to preinjury level of functioning. Results: Fifteen patients met the inclusion/exclusion criteria and participated in our survey. Patients were followed up for an average of 19 months after injury. Overall mean age was 61 years. Injury followed a mechanical fall or a road traffic accident in 11 and 4 cases, respectively. External immobilization was achieved by halo vest only in nine patients, soft collar only in two patients (13%), and through a sequential combination in the remaining 4 (27%). This was deployed for a mean of 7.8 months. Radiological studies at the last follow-up showed bony healing (27%), fibrous nonunion (60%), and persistent instability (13%). Patients reported gradual recovery of function throughout the 1st year after injury with levels above 70% of preinjury functioning achieved by 13% of patients at 6 months, 33% at 9 months, and 47% at 12 months. Overall satisfaction with nonsurgical management was 68%. Conclusion: In selected patients with type II odontoid fractures, external immobilization represents a good option with acceptable course of recovery. PMID

  11. [Bone fracture and the healing mechanisms. Fragility fracture and bone quality].

    PubMed

    Mawatari, Taro; Iwamoto, Yukihide

    2009-05-01

    Fracture occurs in bone having less than normal elastic resistance without any violence. Numerous terms have been used to classify various types of fractures from low trauma events; "fragility fracture", "stress fracture", "insufficiency fracture", "fatigue fracture", "pathologic fracture", etc. The definitions of these terms and clinical characteristics of these fractures are discussed. Also state-of-the-art bone quality assessments; Finite element analysis of clinical CT scans, assessments of the Microdamage, and the Cross-links of Collagen are introduced in this review.

  12. Fracture opening/propagation behavior and their significance on pressure-time records during hydraulic fracturing

    SciTech Connect

    Takashi Kojima; Yasuhiko Nakagawa; Koji Matsuki; Toshiyuki Hashida

    1992-01-01

    Hydraulic fracturing with constant fluid injection rate was numerically modeled for a pair of rectangular longitudinal fractures intersecting a wellbore in an impermeable rock mass, and numerical calculations have been performed to investigate the relations among the form of pressure-time curves, fracture opening/propagation behavior and permeability of the mechanically closed fractures. The results have shown that both permeability of the fractures and fluid injection rate significantly influence the form of the pressure-time relations on the early stage of fracture opening. Furthermore it has been shown that wellbore pressure during fracture propagation is affected by the pre-existing fracture length.

  13. A 3-Dimensional discrete fracture network generator to examine fracture-matrix interaction using TOUGH2

    SciTech Connect

    Ito, Kazumasa; Yongkoo, Seol

    2003-04-09

    Water fluxes in unsaturated, fractured rock involve the physical processes occurring at fracture-matrix interfaces within fracture networks. Modeling these water fluxes using a discrete fracture network model is a complicated effort. Existing preprocessors for TOUGH2 are not suitable to generate grids for fracture networks with various orientations and inclinations. There are several 3-D discrete-fracture-network simulators for flow and transport, but most of them do not capture fracture-matrix interaction. We have developed a new 3-D discrete-fracture-network mesh generator, FRACMESH, to provide TOUGH2 with information about the fracture network configuration and fracture-matrix interactions. FRACMESH transforms a discrete fracture network into a 3 dimensional uniform mesh, in which fractures are considered as elements with unique rock material properties and connected to surrounding matrix elements. Using FRACMESH, individual fractures may have uniform or random aperture distributions to consider heterogeneity. Fracture element volumes and interfacial areas are calculated from fracture geometry within individual elements. By using FRACMESH and TOUGH2, fractures with various inclinations and orientations, and fracture-matrix interaction, can be incorporated. In this paper, results of flow and transport simulations in a fractured rock block utilizing FRACMESH are presented.

  14. Teaching Externally: Lecturers' Viewpoints. Occasional Paper 6.

    ERIC Educational Resources Information Center

    Roberts, David, Ed.

    Perspectives of academic staff who have been involved in teaching externally are presented in three papers. In "Teaching Students Externally: The First Twelve Years," Frank Molloy examines three aspects of teaching by the external mode: preparing materials, making assignments, and providing educational experiences for students at the…

  15. Your College Degree: The External Degree Way.

    ERIC Educational Resources Information Center

    Haponski, William C.; And Others

    Information on undertaking an external degree program to obtain a college education is presented. An external degree program is one that has no, or minimal requirements for residence (on-campus attendance). Most often it can be entered at any time of the year and usually grants credit for documented learning already acquired. An external degree…

  16. 49 CFR 195.108 - External pressure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false External pressure. 195.108 Section 195.108 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Design Requirements § 195.108 External pressure. Any external pressure that will be exerted on...

  17. 46 CFR 64.19 - External pressure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false External pressure. 64.19 Section 64.19 Shipping COAST... HANDLING SYSTEMS Standards for an MPT § 64.19 External pressure. (a) A tank without a vacuum breaker must be designed to withstand an external pressure of 71/2 psig or more. (b) A tank with a vacuum...

  18. 46 CFR 64.19 - External pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false External pressure. 64.19 Section 64.19 Shipping COAST... HANDLING SYSTEMS Standards for an MPT § 64.19 External pressure. (a) A tank without a vacuum breaker must be designed to withstand an external pressure of 71/2 psig or more. (b) A tank with a vacuum...

  19. 49 CFR 195.108 - External pressure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false External pressure. 195.108 Section 195.108 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Design Requirements § 195.108 External pressure. Any external pressure that will be exerted on...

  20. 46 CFR 154.452 - External pressure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false External pressure. 154.452 Section 154.452 Shipping... Independent Tank Type C and Process Pressure Vessels § 154.452 External pressure. The design external pressure...) for tanks without a vacuum relief valve. P2=0, or the pressure relief valve setting for an...

  1. 49 CFR 195.108 - External pressure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false External pressure. 195.108 Section 195.108 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Design Requirements § 195.108 External pressure. Any external pressure that will be exerted on...

  2. 46 CFR 154.452 - External pressure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false External pressure. 154.452 Section 154.452 Shipping... Independent Tank Type C and Process Pressure Vessels § 154.452 External pressure. The design external pressure...) for tanks without a vacuum relief valve. P2=0, or the pressure relief valve setting for an...

  3. 46 CFR 64.19 - External pressure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false External pressure. 64.19 Section 64.19 Shipping COAST... HANDLING SYSTEMS Standards for an MPT § 64.19 External pressure. (a) A tank without a vacuum breaker must be designed to withstand an external pressure of 71/2 psig or more. (b) A tank with a vacuum...

  4. 46 CFR 154.452 - External pressure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false External pressure. 154.452 Section 154.452 Shipping... Independent Tank Type C and Process Pressure Vessels § 154.452 External pressure. The design external pressure...) for tanks without a vacuum relief valve. P2=0, or the pressure relief valve setting for an...

  5. 46 CFR 154.452 - External pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false External pressure. 154.452 Section 154.452 Shipping... Independent Tank Type C and Process Pressure Vessels § 154.452 External pressure. The design external pressure...) for tanks without a vacuum relief valve. P2=0, or the pressure relief valve setting for an...

  6. 46 CFR 64.19 - External pressure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false External pressure. 64.19 Section 64.19 Shipping COAST... HANDLING SYSTEMS Standards for an MPT § 64.19 External pressure. (a) A tank without a vacuum breaker must be designed to withstand an external pressure of 71/2 psig or more. (b) A tank with a vacuum...

  7. 49 CFR 195.108 - External pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false External pressure. 195.108 Section 195.108 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Design Requirements § 195.108 External pressure. Any external pressure that will be exerted on...

  8. 49 CFR 195.108 - External pressure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false External pressure. 195.108 Section 195.108 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Design Requirements § 195.108 External pressure. Any external pressure that will be exerted on...

  9. 46 CFR 64.19 - External pressure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false External pressure. 64.19 Section 64.19 Shipping COAST... HANDLING SYSTEMS Standards for an MPT § 64.19 External pressure. (a) A tank without a vacuum breaker must be designed to withstand an external pressure of 71/2 psig or more. (b) A tank with a vacuum...

  10. 46 CFR 154.452 - External pressure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false External pressure. 154.452 Section 154.452 Shipping... Independent Tank Type C and Process Pressure Vessels § 154.452 External pressure. The design external pressure...) for tanks without a vacuum relief valve. P2=0, or the pressure relief valve setting for an...

  11. C2 Body Fracture: Report of Cases Managed Conservatively by Philadelphia Collar

    PubMed Central

    Sadeghian, Homa

    2016-01-01

    Study Design Case series. Purpose To present results of conservative management in patients with pure C2 body fractures. Overview of Literature Axis body fractures, a less common subgroup of C2 fractures, are commonly classified as vertical coronal, vertical sagittal, and transverse subtypes. While the treatment paradigm for other C2 fractures is clear, there is insufficient evidence to support treatment guidelines for C2 body fractures. Methods Eleven patients with pure C2 body fractures were managed with external immobilization and followed thereafter. Results All neurologic examinations were normal. In computed tomography (CT) scans, four, two, three, and two patients had a coronal, sagittal, horizontal, and burst fracture, respectively. Magnetic resonance imaging showed hematoma and partial rupture in the anterior longitudinal ligament in four patients, posterior ligamentous complex injury in one, and normal ligamentous structure in six. All fractures were managed conservatively using the Philadelphia collar, which was continued until complete disappearance of symptoms (within 1–3 months in all patients). The decision to discontinue the neck collar was made by a dynamic neck X-ray and CT scan that showed complete bony fusion. All patients were then followed for an additional 1.5 years (mean follow-up of 21 months for all patients). No patient showed any neurologic symptoms or deficits during the follow-up period. Conclusions In patients with pure C2 body fracture, non-operative management with Philadelphia neck collar is a safe and efficacious option, even in the presence of some sort of ligamentous injury. PMID:27790321

  12. Fractal modeling of natural fracture networks

    SciTech Connect

    Ferer, M.; Dean, B.; Mick, C.

    1995-06-01

    West Virginia University will implement procedures for a fractal analysis of fractures in reservoirs. This procedure will be applied to fracture networks in outcrops and to fractures intersecting horizontal boreholes. The parameters resulting from this analysis will be used to generate synthetic fracture networks with the same fractal characteristics as the real networks. Recovery from naturally fractured, tight-gas reservoirs is controlled by the fracture network. Reliable characterization of the actual fracture network in the reservoir is severely limited. The location and orientation of fractures intersecting the borehole can be determined, but the length of these fractures cannot be unambiguously determined. Because of the lack of detailed information about the actual fracture network, modeling methods must represent the porosity and permeability associated with the fracture network, as accurately as possible with very little a priori information. In the sections following, the authors will (1) present fractal analysis of the MWX site, using the box-counting procedure; (2) review evidence testing the fractal nature of fracture distributions and discuss the advantages of using the fractal analysis over a stochastic analysis; and (3) present an efficient algorithm for producing a self-similar fracture networks which mimic the real MWX outcrop fracture network.

  13. The Role of Oxygen during Fracture Healing

    PubMed Central

    Lu, Chuanyong; Saless, Neema; Wang, Xiaodong; Sinha, Arjun; Decker, Sebastian; Kazakia, Galateia; Hou, Huagang; Williams, Benjamin; Swartz, Harold M.; Hunt, Thomas K.; Miclau, Theodore; Marcucio, Ralph S.

    2016-01-01

    Oxygen affects the activity of multiple skeletogenic cells and is involved in many processes that are important for fracture healing. However, the role of oxygen in fracture healing has not been fully studied. Here we systematically examine the effects of oxygen tension on fracture healing and test the ability of hyperoxia to rescue healing defects in a mouse model of ischemic fracture healing. Mice with tibia fracture were housed in custom-built gas chambers and groups breathed a constant atmosphere of 13% oxygen (hypoxia), 21% oxygen (normoxia), or 50% oxygen (hyperoxia). The influx of inflammatory cells to the fracture site, stem cell differentiation, tissue vascularization, and fracture healing were analyzed. In addition, the efficacy of hyperoxia (50% breathing oxygen) as a treatment regimen for fracture nonunion was tested. Hypoxic animals had decreased tissue vascularity, decreased bone formation, and delayed callus remodeling. Hyperoxia increased tissue vascularization, altered fracture healing in un-complicated fractures, and improved bone repair in ischemia-induced delayed fracture union. However, neither hypoxia nor hyperoxia significantly altered chondrogenesis or osteogenesis during early stages of fracture healing, and infiltration of macrophages and neutrophils was not affected by environmental oxygen after bone injury. In conclusion, our results indicate that environmental oxygen levels affect tissue vascularization and fracture healing, and that providing oxygen to patients with fractures accompanied by ischemia may be beneficial. PMID:23063782

  14. Fracture process zone in granite

    USGS Publications Warehouse

    Zang, A.; Wagner, F.C.; Stanchits, S.; Janssen, C.; Dresen, G.

    2000-01-01

    In uniaxial compression tests performed on Aue granite cores (diameter 50 mm, length 100 mm), a steel loading plate was used to induce the formation of a discrete shear fracture. A zone of distributed microcracks surrounds the tip of the propagating fracture. This process zone is imaged by locating acoustic emission events using 12 piezoceramic sensors attached to the samples. Propagation velocity of the process zone is varied by using the rate of acoustic emissions to control the applied axial force. The resulting velocities range from 2 mm/s in displacement-controlled tests to 2 ??m/s in tests controlled by acoustic emission rate. Wave velocities and amplitudes are monitored during fault formation. P waves transmitted through the approaching process zone show a drop in amplitude of 26 dB, and ultrasonic velocities are reduced by 10%. The width of the process zone is ???9 times the grain diameter inferred from acoustic data but is only 2 times the grain size from optical crack inspection. The process zone of fast propagating fractures is wider than for slow ones. The density of microcracks and acoustic emissions increases approaching the main fracture. Shear displacement scales linearly with fracture length. Fault plane solutions from acoustic events show similar orientation of nodal planes on both sides of the shear fracture. The ratio of the process zone width to the fault length in Aue granite ranges from 0.01 to 0.1 inferred from crack data and acoustic emissions, respectively. The fracture surface energy is estimated from microstructure analysis to be ???2 J. A lower bound estimate for the energy dissipated by acoustic events is 0.1 J. Copyright 2000 by the American Geophysical Union.

  15. Growth Kinematics of Opening-Mode Fractures

    NASA Astrophysics Data System (ADS)

    Eichhubl, P.; Alzayer, Y.; Laubach, S.; Fall, A.

    2014-12-01

    Fracture aperture is a primary control on flow in fractured reservoirs of low matrix permeability including unconventional oil and gas reservoirs and most geothermal systems. Guided by principles of linear elastic fracture mechanics, fracture aperture is generally assumed to be a linear function of fracture length and elastic material properties. Natural opening-mode fractures with significant preserved aperture are observed in core and outcrop indicative of fracture opening strain accommodated by permanent solution-precipitation creep. Fracture opening may thus be decoupled from length growth if the material effectively weakens after initial elastic fracture growth by either non-elastic deformation processes or changes in elastic properties. To investigate the kinematics of fracture length and aperture growth, we reconstructed the opening history of three opening-mode fractures that are bridged by crack-seal quartz cement in Travis Peak Sandstone of the SFOT-1 well, East Texas. Similar crack-seal cement bridges had been interpreted to form by repeated incremental fracture opening and subsequent precipitation of quartz cement. We imaged crack-seal cement textures for bridges sampled at varying distance from the tips using scanning electron microscope cathodoluminescence, and determined the number and thickness of crack-seal cement increments as a function of position along the fracture length and height. Observed trends in increment number and thickness are consistent with an initial stage of fast fracture propagation relative to aperture growth, followed by a stage of slow propagation and pronounced aperture growth. Consistent with fluid inclusion observations indicative of fracture opening and propagation occurring over 30-40 m.y., we interpret the second phase of pronounced aperture growth to result from fracture opening strain accommodated by solution-precipitation creep and concurrent slow, possibly subcritical, fracture propagation. Similar deformation

  16. Fracture pain-Traveling unknown pathways.

    PubMed

    Alves, Cecília J; Neto, Estrela; Sousa, Daniela M; Leitão, Luís; Vasconcelos, Daniel M; Ribeiro-Silva, Manuel; Alencastre, Inês S; Lamghari, Meriem

    2016-04-01

    An increase of fracture incidence is expected for the next decades, mostly due to the undeniable increase of osteoporotic fractures, associated with the rapid population ageing. The rise in sports-related fractures affecting the young and active population also contributes to this increased fracture incidence, and further amplifies the economical burden of fractures. Fracture often results in severe pain, which is a primary symptom to be treated, not only to guarantee individual's wellbeing, but also because an efficient management of fracture pain is mandatory to ensure proper bone healing. Here, we review the available data on bone innervation and its response to fracture, and discuss putative mechanisms of fracture pain signaling. In addition, the common therapeutic approaches to treat fracture pain are discussed. Although there is still much to learn, research in fracture pain has allowed an initial insight into the mechanisms involved. During the inflammatory response to fracture, several mediators are released and will putatively activate and sensitize primary sensory neurons, in parallel, intense nerve sprouting that occurs in the fracture callus area is also suggested to be involved in pain signaling. The establishment of hyperalgesia and allodynia after fracture indicates the development of peripheral and central sensitization, still, the underlying mechanisms are largely unknown. A major concern during the treatment of fracture pain needs to be the preservation of proper bone healing. However, the most common therapeutic agents, NSAIDS and opiates, can cause significant side effects that include fracture repair impairment. The understanding of the mechanisms of fracture pain signaling will allow the development of mechanisms-based therapies to effectively and safely manage fracture pain.

  17. [Discharges for external injuries from a hospital in Ciudad Juarez, Mexico].

    PubMed

    Díaz-Apodaca, Beatriz A; De Cosio, Federico G; Moye-Elizalde, Gustavo; Fornelli-Laffon, Felipe F

    2012-05-01

    In Ciudad Juarez, Chihuahua, Mexico, morbidity and mortality from injuries have increased alarmingly since 2008. This paper aims to examine the changes in the number of hospital discharges for external injuries recorded during the 2008-2010 period in a hospital in Ciudad Juarez. A descriptive retrospective study conducted at the Ciudad Juarez General Hospital looked at the incidence of external injuries as the reason for hospital discharges during the period under analysis. The average proportion of hospital discharges attributed to external injuries was 27%, with the 25-44-year-old age group being the most affected. More than half of the discharges were for fractures. The incidence rate of hospital discharges attributed to injuries in Ciudad Juarez was almost four times greater than that reported at the national level.

  18. [Timing of surgical treatment of fractures of multiply iniured patients - from science to tactics].

    PubMed

    Simons, Tomi; Brinck, Tuomas; Handolin, Lauri

    2016-01-01

    Timing of the treatment of orthopaedic injuries in multiply injured patients has undergone changes. The timing of definitive fracture management has varied from several weeks to within hours of injury. In many studies a clear benefit has been identified from early definitive care of long bone fractures: early total care (ETC). The most seriously injured patients benefit from damage control orthopaedics, an approach employing primary external fixator stabilization followed by secondary intramedullary nailing. Debate over these approaches with enhanced understanding of biological response to injury has led to recent emphasis on the need for aggressive patient monitoring and continued multidisciplinary evaluation of the patient's physiological response to treatment.

  19. Delayed treatment of a neonatal type-I Monteggia fracture-dislocation: a case report.

    PubMed

    Smith, William R; Kozin, Scott H; Zlotolow, Dan A

    2017-03-01

    Delayed diagnosis of a Monteggia fracture-dislocation changes a straightforward, treatable injury into a complex problem. Acute neonatal injuries may be missed because of the inability to visualize the unossified skeleton on radiography, interpreted later as 'congenital' dislocations. We report the case of a 14-month-old with a neonatal Monteggia type-I fracture-dislocation secondary to birth trauma, with anterior radial head dislocation and plastic deformation of the ulna. Uniplanar external fixation was used to restore ulnar length and correct angulation, with subsequent radiocapitellar joint closed reduction. Joint congruity was maintained at the 2-year follow-up, with articular remodeling shown on serial arthrogram.

  20. Compensating Mechanisms That Minimize Flux Variability Through Unsaturated Fractures

    NASA Astrophysics Data System (ADS)

    Nimmo, J. R.; Su, G. W.

    2001-12-01

    Fast flow in fractures and macropores is a major cause of discrepancy between measurements and unsaturated flow models. Most models treat preferential flow as diffuse Darcy-Richards flow, so it is important to ascertain whether the mechanisms of unsaturated fracture flow accord with Darcy's law. The key issue is whether water flux is directly proportional to driving force with a proportionality factor, the hydraulic conductivity (K), that is independent of flux and force. We consider flow in a partially water-filled fracture with continuously supplied (e.g. ponded) water, responding to a change in driving force such as a change in tilt angle with respect to gravity. Four general flow modes, alone or in combination, can account for the dominant portion of the flow for these conditions, as shown by the experimental studies of Su and others (1999) and Tokunaga and Wan (1997). (1) Film flow occurs within a sheet or film that contacts a wall of the fracture. (2) Connected rivulet flow occurs when a rivulet that bridges across the fracture aperture by capillary force is consistently connected across the domain of interest from the inflow point to the outflow point. (3) Snapping rivulet flow occurs if the rivulet sometimes but not always extends continuously across the domain. (4) Pulsating-blob flow occurs in isolated blobs that bridge across the fracture aperture and move across the domain of interest without ever extending completely between the inflow and outflow points. Where fractures are large enough that the air-water interfaces are free to change shape or position in response to an externally applied change, each flow mode has its own characteristic relation between force and flow rate. This contrasts with the air-water interfaces commonly visualized in fine-textured media, in which the interface is constrained to a particular shape and position by capillarity and adsorption, so that the consistent geometry of the effective flow conduits leads to Darcian flow. In

  1. [Surgical stabilization of multiple rib fractures successfully achieved with the use of long metalic plates].

    PubMed

    Tanaka, A; Sato, T; Osawa, H; Koyanagi, T; Maekawa, K; Watanabe, N; Nakase, A; Sakata, J; Kamada, K

    1998-05-01

    Surgical stabilization of multiple rib fractures in 5 male patients was successfully achieved with the use of orthopedic A-O metalic plates, which are called reconstruction plates. In each patient, we prevented deformity of the rib cage and flail chest which frequently occurs after multiple rib fractures. Three of these patients received emergency operations because of severe hemopneumothorax and flail chest due to crushing injuries to the chest. They were treated by the standard thoracotomy, hemostasis of intrapleural bleeding, and stabilization of fractured ribs with reconstruction plates, in addition two of the patients underwent a single lobectomy to control the pulmonary hemorrhage. Another two patients were treated with mechanical ventilation and closed-tube thoracotomy following the chest trauma because their thoracic bleeding from drainage tubes was tolerable. But flail chest and respiratory insufficiency did not improve, in spite of positive controlled ventilation as a mode of internal pneumatic stabilization. Then surgical stabilization of the fractured ribs with these plates was carried out ten to twelve days after the accidents in each case. All patients tolerated the surgical procedures well and were successfully removed from the respirator, demonstrating complete stability of the chest wall. The long metal reconstruction plates with many perforations were very useful for the external fixation of segmentary fractured ribs as an external brace. This was because they were long enough to cover the whole length of the fractured ribs and moderately soft enough to be appropriately bent or twisted by hand at the time of operation. Moreover a number of holes in it allowed the suture to pass through the plate and rib, avoiding displacement of the prosthesis. This is the first report which describes the usefulness of orthopedic reconstruction plates for the stabilization of multiple rib fractures.

  2. Monitoring hydraulic fracture growth: Laboratory experiments

    SciTech Connect

    Groenenboom, J.; Dam, D.B. van

    2000-04-01

    The authors carry out small-scale hydraulic fracture experiments to investigate the physics of hydraulic fracturing. The laboratory experiments are combined with time-lapse ultrasonic measurements with active sources using both compressional and shear-wave transducers. For the time-lapse measurements they focus on ultrasonic measurement changes during fracture growth. As a consequence they can detect the hydraulic fracture and characterize its shape and geometry during growth. Hence, this paper deals with fracture characterization using time-lapse acoustic data. Hydraulic fracturing is used in the oil and gas industry to stimulate reservoir production.

  3. Fracture and Medium Modeling, by Analizing Hidraulic Fracturing Induced Microseismicity

    NASA Astrophysics Data System (ADS)

    Gomez Alba, S.; Vargas Jiménez, C. A.

    2014-12-01

    Hydraulic fracturing is an essential technology for most unconventional hydrocarbon resources and many conventional ones as well. The primary limitation on the improvement and optimization of the fracturing process is the minimal access to observe the behavior of the fracture in the subsurface. Without direct observational evidence, hypothetical mechanisms must be assumed and then tested for their validity with indirect information such as wellbore measurements, indirect production and pressure behavior. One of the most important sources of information today is the relation made between micro seismic source mechanisms and fracture behavior. Hydraulic fractures induce some level of micro seismicity when the stress conditions in the Earth are altered by changes in stress during the operations. The result is the sudden movement between rock elements and the radiation of both compressional and shear energy in a seismic range that can be detected and recorded with sensitive receivers. The objective of this work is to provide reasonable information when applying inversion methods in order to estimate the vertical and horizontal spatial heterogeneities in medium and energy radiation distribution of microseisms while fracking operations. The method consist in record microseisms at a previous lineal array of stations (triaxial accelerometers) which are located close to the source coordinates and cover the area of study. The analysis clarify some ideas about what information can be gained from the micro seismic source data and according to the obtained results, what kind of comparisons and associations might be done to evaluate the fracking performance operation. Non uniformities in medium such as faults would be revealed by interpreted scattering coefficients. Fracture properties like distance, velocity and orientation would be also determined by analyzing energy radiation.

  4. Selective perceptions of hydraulic fracturing.

    PubMed

    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.

  5. Fracture Supracondylar Humerus: A Review

    PubMed Central

    Kumar, Vineet

    2016-01-01

    Fracture supracondylar humerus is one of the most common fractures encountered in pediatric age group at all levels (both rural and urban). Thus it needs a special review in its management protocol as per the changing trend. Modified Gartland classification is the most accepted classification and has its importance in decision making regarding management and prognosis. Neurovascular complications are mostly associated with Type III A, III B and Type IV variety and they most of the time need surgical intervention for stabilization, exploration of brachial artery, sometimes median nerve exploration and reduction of fracture. Cubitus varus is the most common associated deformity associated with this fracture (especially in Type III A). The aim of the review was to develop an insight for the understanding of variations in presentation and management of supracondylar fracture of the humerus (both simplicity and complexity) and the flowing trend in addition to the recent advances to deal with this particular pediatric orthopaedic entity which often presents as an emergency. PMID:28208961

  6. Test-Free Fracture Toughness

    NASA Technical Reports Server (NTRS)

    Minnetyan, Levon; Chamis, Christos C. (Technical Monitor)

    2003-01-01

    Computational simulation results can give the prediction of damage growth and progression and fracture toughness of composite structures. The experimental data from literature provide environmental effects on the fracture behavior of metallic or fiber composite structures. However, the traditional experimental methods to analyze the influence of the imposed conditions are expensive and time consuming. This research used the CODSTRAN code to model the temperature effects, scaling effects and the loading effects of fiber/braided composite specimens with and without fiber-optic sensors on the damage initiation and energy release rates. The load-displacement relationship and fracture toughness assessment approach is compared with the test results from literature and it is verified that the computational simulation, with the use of established material modeling and finite element modules, adequately tracks the changes of fracture toughness and subsequent fracture propagation for any fiber/braided composite structure due to the change of fiber orientations, presence of large diameter optical fibers, and any loading conditions.

  7. [Fractures of the tibial shaft].

    PubMed

    Märdian, S; Schwabe, P; Schaser, K-D

    2015-02-01

    The tibia shaft is the most often fractured long bone of human beings. Among others traffic accidents (37.5 %), falls (17.8 %), sport accidents (30.9 %) and assaults (4.5 %) are typical mechanisms. A brief clinical examination including the correct classification of the fracture pattern and even more important the degree of the soft tissue damage are the most crucial factors for the following therapeutic cascade. This follows a defined algorithm based on the degree of soft tissue damage. As biplanar X-ray diagnostics are obligatory, CT scans are subject to complex fracture patterns and accompanying intraarticular pathologies.The treatment of tibial shaft fractures is the preserve of operative stabilization, which should be done primarily depending on the degree of the soft tissue injury. Here intramedullary methods - especially intramedullary nailing - are the golden standard.The most serious complication of these fractures is the development of a compartment syndrome. This requires rapid diagnosis and an adequate surgical management in order to avoid extensive muscle necrosis with ischaemic contractures and irreversible neurovascular deficits. Apart from postoperative infections, which are the predominant complication especially in open injuries, non union provide typical and late complications which are partly difficult to treat. These should, depending on their type, follow a dedicated treatment algorithm.

  8. Frontal Sinus Fractures: Current Concepts

    PubMed Central

    Strong, E. Bradley

    2009-01-01

    Frontal sinus injuries may range from isolated anterior table fractures resulting in a simple aesthetic deformity to complex fractures involving the frontal recess, orbits, skull base, and intracranial contents. The risk of long-term morbidity can be significant. Optimal treatment strategies for the management of frontal sinus fractures remain controversial. However, it is critical to have a thorough understanding of frontal sinus anatomy as well as the current treatment strategies used to manage these injuries. A thorough physical exam and thin-cut, multiplanar (axial, coronal, and sagittal) computed tomography scan should be performed in all patients suspected of having a frontal sinus fracture. The most appropriate treatment strategy can be determined by assessing five anatomic parameters including the: frontal recess, anterior table integrity, posterior table integrity, dural integrity, and presence of a cerebrospinal fluid leak. A well thought out management strategy and meticulous surgical techniques are critical to success. The primary surgical goal is to provide a safe sinus while minimizing patient morbidity. This article offers an anatomically based treatment algorithm for the management of frontal sinus fractures and highlights the key steps to surgical repair. PMID:22110810

  9. Clinical Analysis of Midfacial Fractures

    PubMed Central

    Yamamoto, Kazuhiko; Matsusue, Yumiko; Horita, Satoshi; Murakami, Kazuhiro; Sugiura, Tsutomu; Kirita, Tadaaki

    2014-01-01

    Purpose: To analyze the features of midfacial fractures. Methods: Data of 320 patients treated for midfacial fractures during the past 10 years were retrospectively analyzed. Results: Patients were 192 male and 128 female. Their age ranged from 1 to 96 years old with the average of 42.1. Injury most frequently occurred by traffic accidents in 168 patients, followed by falls in 78, assaults in 31 and sports in 25. Pattern of the fractures was classified into zygoma in 159 patients, alveolus in 60, multiple sites in 54, maxilla in 45 and nasal bone in 2. Facial injury severity scale ranged from 1 to 12 with the average of 1.52. Injuries to other sites of the body were found in 90 patients. Fractures of multiple sites showed higher facial injury severity scale and were associated with injuries to other sites of the body at a higher rate. Observation was most frequently chosen in 153 patients, followed by open reduction and internal fixation in 72, intramaxillary fixation in 43 and transcutaneous reduction in 26. Conclusions: Midfacial fractures showed a variety of features in terms of the site and severity and associated injuries. Understanding these features is important to manage these patients properly. PMID:24757396

  10. Externally blown flap impingement noise

    NASA Technical Reports Server (NTRS)

    Lasagna, P. L.; Putnam, T. W.

    1972-01-01

    Tests of the noise produced by the impingement of the jet exhaust on the wing and flap for an externally blown flap system were conducted with a CF700 turbofan engine and an F-111B wing panel. The noise produced with a daisy nozzle installed on the engine was greater than that produced by a conical nozzle at the same thrust. The presence of the wing next to the test nozzles increased the noise, as did increasing the flap deflection angle. Compared with the conical nozzle, the daisy nozzle produced slightly less noise at a flap deflection of 60 deg but produced more noise at the lower flap deflections tested. Tests showed that the single-slotted flap deflected 60 deg, produced less noise than the double-slotted flaps. Also, maintaining the maximum distance between the exit nozzle and flap system resulted in a minor reduction in noise.

  11. Automated external defibrillation: laboratory evaluation.

    PubMed

    Rosenthal, E; Carroll, D; Vincent, R; Chamberlain, D A

    1984-04-01

    Twelve samples of ventricular fibrillation were fed into nine automated external defibrillator-pacemakers ( AEDP , "Heart Aid") of recent design. All the devices recognised and defibrillated ventricular fibrillation in seven of the samples within 30 sec. None of the devices reacted to two of the samples; in the remaining three there was inter-device variation ranging from an appropriate response to no response, as well as inappropriate pacing or delay in recognition and treatment. Poor recognition of some ventricular fibrillation waveforms with considerable inter-device variation limits the usefulness of this model. A new prototype responded more consistently and future models may be of value in community resuscitation. The difficulty of evaluating the diagnostic capability of AEDP devices in clinical use makes comprehensive laboratory testing essential prior to release.

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

    NASA Astrophysics Data System (ADS)

    Margolin, B.; Sorokin, A.; Shvetsova, V.; Minkin, A.; Potapova, V.; Smirnov, V.

    2016-11-01

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

  13. Laboratory Visualization of Hydraulic Fracture Propagation and Interaction with a Network of Preexisting Fractures

    NASA Astrophysics Data System (ADS)

    Nakagawa, S.; Kneafsey, T. J.; Borglin, S. E.

    2015-12-01

    We present optical visualization experiments of hydraulic fracture propagation within transparent rock-analogue samples containing a network of preexisting fractures. Natural fractures and heterogeneities in rock have a great impact on hydraulic fracture propagation and resulting improvements in reservoir permeability. In recent years, many sophisticated numerical simulations on hydraulic fracturing have been conducted. Laboratory experiments on hydraulic fracturing are often performed with acoustic emission (Micro Earthquake) monitoring, which allows detection and location of fracturing and fracture propagation. However, the detected fractures are not necessarily hydraulically produced fractures which provide permeable pathways connected to the injection (and production) well. The primary objectives of our visualization experiments are (1) to obtain quantitative visual information of hydraulic fracture propagation affected by pre-existing fractures and (2) to distinguish fractures activated by the perturbed stress field away from the injected fluid and hydraulically produced fractures. The obtained data are also used to develop and validate a new numerical modeling technique (TOUGH-RBSN [Rigid-Body-Spring-Network] model) for hydraulic fracturing simulations, which is presented in a companion paper. The experiments are conducted using transparent soda-lime glass cubes (10 cm × 10 cm × 10 cm) containing either (1) 3D laser-engraved artificial fractures and fracture networks or (2) a random network of fractures produced by rapid thermal quenching. The strength (and also the permeability for the latter) of the fractures can be altered to examine their impact on hydraulic fracturing. The cubes are subjected to true-triaxial stress within a polyaxial loading frame, and hydraulic fractures are produced by injecting fluids with a range of viscosity into an analogue borehole drilled in the sample. The visual images of developing fractures are obtained both through a port

  14. Discrete modeling of hydraulic fracturing processes in a complex pre-existing fracture network

    NASA Astrophysics Data System (ADS)

    Kim, K.; Rutqvist, J.; Nakagawa, S.; Houseworth, J. E.; Birkholzer, J. T.

    2015-12-01

    Hydraulic fracturing and stimulation of fracture networks are widely used by the energy industry (e.g., shale gas extraction, enhanced geothermal systems) to increase permeability of geological formations. Numerous analytical and numerical models have been developed to help understand and predict the behavior of hydraulically induced fractures. However, many existing models assume simple fracturing scenarios with highly idealized fracture geometries (e.g., propagation of a single fracture with assumed shapes in a homogeneous medium). Modeling hydraulic fracture propagation in the presence of natural fractures and homogeneities can be very challenging because of the complex interactions between fluid, rock matrix, and rock interfaces, as well as the interactions between propagating fractures and pre-existing natural fractures. In this study, the TOUGH-RBSN code for coupled hydro-mechanical modeling is utilized to simulate hydraulic fracture propagation and its interaction with pre-existing fracture networks. The simulation tool combines TOUGH2, a simulator of subsurface multiphase flow and mass transport based on the finite volume approach, with the implementation of a lattice modeling approach for geomechanical and fracture-damage behavior, named Rigid-Body-Spring Network (RBSN). The discrete fracture network (DFN) approach is facilitated in the Voronoi discretization via a fully automated modeling procedure. The numerical program is verified through a simple simulation for single fracture propagation, in which the resulting fracture geometry is compared to an analytical solution for given fracture length and aperture. Subsequently, predictive simulations are conducted for planned laboratory experiments using rock-analogue (soda-lime glass) samples containing a designed, pre-existing fracture network. The results of a preliminary simulation demonstrate selective fracturing and fluid infiltration along the pre-existing fractures, with additional fracturing in part

  15. Incidence of fractures requiring inpatient care

    PubMed Central

    Somersalo, Axel; Kautiainen, Hannu; Lönnroos, Eija; Heinänen, Mikko; Kiviranta, Ilkka

    2014-01-01

    Background The overall incidence of fractures has been addressed in several studies, but there are few data on different types of fractures that require inpatient care, even though they account for considerable healthcare costs. We determined the incidence of limb and spine fractures that required hospitalization in people aged ≥ 16 years. Patients and methods We collected data on the diagnosis (ICD10 code), procedure code (NOMESCO), and 9 additional characteristics of patients admitted to the trauma ward of Central Finland Hospital between 2002 and 2008. Incidence rates were calculated for all fractures using data on the population at risk. Results and interpretation During the study period, 3,277 women and 2,708 men sustained 3,750 and 3,030 fractures, respectively. The incidence of all fractures was 4.9 per 103 person years (95% CI: 4.8–5.0). The corresponding numbers for women and men were 5.3 (5.1–5.4) and 4.5 (4.3–4.6). Fractures of the hip, ankle, wrist, spine, and proximal humerus comprised two-thirds of all fractures requiring hospitalization. The proportion of ankle fractures (17%) and wrist fractures (9%) was equal to that of hip fractures (27%). Four-fifths of the hospitalized fracture patients were operated. In individuals aged < 60 years, fractures requiring hospitalization were twice as common in men as in women. In individuals ≥ 60 years of age, the opposite was true. PMID:24694275

  16. Capillary fracturing in granular media.

    PubMed

    Holtzman, Ran; Szulczewski, Michael L; Juanes, Ruben

    2012-06-29

    We study the displacement of immiscible fluids in deformable, noncohesive granular media. Experimentally, we inject air into a thin bed of water-saturated glass beads and observe the invasion morphology. The control parameters are the injection rate, the bead size, and the confining stress. We identify three invasion regimes: capillary fingering, viscous fingering, and "capillary fracturing," where capillary forces overcome frictional resistance and induce the opening of conduits. We derive two dimensionless numbers that govern the transition among the different regimes: a modified capillary number and a fracturing number. The experiments and analysis predict the emergence of fracturing in fine-grained media under low confining stress, a phenomenon that likely plays a fundamental role in many natural processes such as primary oil migration, methane venting from lake sediments, and the formation of desiccation cracks.

  17. Capillary Fracturing in Granular Media

    NASA Astrophysics Data System (ADS)

    Holtzman, Ran; Szulczewski, Michael L.; Juanes, Ruben

    2012-06-01

    We study the displacement of immiscible fluids in deformable, noncohesive granular media. Experimentally, we inject air into a thin bed of water-saturated glass beads and observe the invasion morphology. The control parameters are the injection rate, the bead size, and the confining stress. We identify three invasion regimes: capillary fingering, viscous fingering, and “capillary fracturing,” where capillary forces overcome frictional resistance and induce the opening of conduits. We derive two dimensionless numbers that govern the transition among the different regimes: a modified capillary number and a fracturing number. The experiments and analysis predict the emergence of fracturing in fine-grained media under low confining stress, a phenomenon that likely plays a fundamental role in many natural processes such as primary oil migration, methane venting from lake sediments, and the formation of desiccation cracks.

  18. Fracture surfaces of irradiated composites

    NASA Technical Reports Server (NTRS)

    Milkovich, Scott M.; Sykes, George F., Jr.; Herakovich, Carl T.

    1987-01-01

    Electron microscopy was used to analyze the fracture surfaces of T300/934 graphite/epoxy unidirectional off-axis tensile coupons which were subjected to 1.0-MeV electron radiation at a rate of 50 Mrad/h for a total dose of 10 Grad. Fracture surfaces from irradiated and nonirradiated specimens tested at 116 K, room temperature, and 394 K were analyzed to assess the influence of radiation and temperature on the mode of failure and variations in constituent material as a function of environmental exposure. Micrographs of fracture surfaces indicate that irradiated specimens are more brittle than nonirradiated specimens at low temperatures. However, at elevated temperatures the irradiated specimens exhibit significantly more plasticity than nonirradiated specimens.

  19. Fracture mechanics of cellular glass

    NASA Technical Reports Server (NTRS)

    Zwissler, J. G.; Adams, M. A.

    1981-01-01

    The fracture mechanics of cellular glasses (for the structural substrate of mirrored glass for solr concentrator reflecting panels) are discussed. Commercial and developmental cellular glasses were tested and analyzed using standard testing techniques and models developed from linear fracture mechanics. Two models describing the fracture behavior of these materials were developed. Slow crack growth behavior in cellular glass was found to be more complex than that encountered in dense glasses or ceramics. The crack velocity was found to be strongly dependent upon water vapor transport to the tip of the moving crack. The existence of a static fatigue limit was not conclusively established, however, it is speculated that slow crack growth behavior in Region 1 may be slower, by orders of magnitude, than that found in dense glasses.

  20. Method for directional hydraulic fracturing

    DOEpatents

    Swanson, David E.; Daly, Daniel W.

    1994-01-01

    A method for directional hydraulic fracturing using borehole seals to confine pressurized fluid in planar permeable regions, comprising: placing a sealant in the hole of a structure selected from geologic or cemented formations to fill the space between a permeable planar component and the geologic or cemented formation in the vicinity of the permeable planar component; making a hydraulic connection between the permeable planar component and a pump; permitting the sealant to cure and thereby provide both mechanical and hydraulic confinement to the permeable planar component; and pumping a fluid from the pump into the permeable planar component to internally pressurize the permeable planar component to initiate a fracture in the formation, the fracture being disposed in the same orientation as the permeable planar component.

  1. Fracture behavior of ferroelectric ceramics

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Lupascu, Doru C.; Lynch, Christopher S.

    1999-06-01

    Piezoelectric actuators are key components in many smart structures applications. Long term reliability of these actuators becomes increasingly important as research makes the transition to commercial applications. Fracture toughness is a material parameter that measures a material's resistance to crack propagation. This is perhaps, one of the most important parameters for reliable device design. This paper reviews recent work by the authors on fracture behavior of ferroelectric ceramics. Vickers indentation data were used to determine the fracture toughness of a coarse and a fine grained PZT and two compositions of PLZT. R-curve data were obtained for two compositions of PLZT. The R-curve data presented here were generated using four point bend specimens with controlled surface flaws. The R-curve results compare favorably with the Vickers indentation data. A comparison of the R-curves for a ferroelectric composition of PLZT and a quadratic electrostrictive composition of PLZT demonstrate the contribution of domain reorientation to the toughening process.

  2. Fracture-dislocations of the elbow joint--strategy for treatment and results.

    PubMed

    Lill, H; Korner, J; Rose, T; Hepp, P; Verheyden, P; Josten, C

    2001-01-01

    Between January 1993 and December 1996, 41 patients with fracture dislocation of the elbow joint were treated in our department. In 28 patients (median age 46 years, range 15-77 years; 16 male, 12 female), a clinical and radiological follow-up was obtained after median 34 months (range 12-59 months). In addition to the humero-ulnar dislocation, isolated fractures were present in 13 patients and combined fractures in 15 (all with involvement of the radial head). Primary neurological deficits were found in 7 and open fractures in 3 patients. In 7 patients, primary definitive surgical therapy was carried out by open reduction and internal fixation. A two-step surgical management (initial closed reduction and immobilization, 5 patients with external fixator, 7 with plaster; secondary open surgical procedure) was performed in 12 and conservative treatment in 9 patients. According to the Leipzig Elbow Score, taking subjective, clinical and radiological criteria into consideration, 4 patients achieved 'excellent' and 5 patients a 'good' result. Ten patients were scored 'moderate' and 9 'poor'. The rate of secondary complications necessitating revision was 36%. Poor results were primarily caused by extensive initial soft-tissue damage, delayed definitive surgical therapy, and ectopic heterotopic ossification. In contrast, fracture localization and degree of arthrosis were not of significant importance for the final outcome. In fracture dislocations, the goal is a primary definitive surgical treatment aiming for early postoperative physiotherapy.

  3. The pattern of femoral diaphyseal fractures in children admitted in Sarawak General Hospital.

    PubMed

    Rasit, A H; Mohammad, A W; Pan, K L

    2006-02-01

    Trend towards changing the face of management for pediatric femoral fractures tends to advocate operative treatment. This study was undertaken to review our current practice in the wake of recent progress in the management of pediatric femoral fractures. Fifty patients with femoral diaphyseal fracture treated in Sarawak General Hospital were reviewed retrospectively after an average follow-up of 2.6 years. There were 36 boys and 14 girls, with a mean age of 6.2 years (range five months to 14 years). Children under six years of age constituted the majority of the patients. Half of the fractures were caused by road traffic accident. Nine patients had associated injuries. The most common site of fracture was at the middle third (N=31). The treatment regimens were delayed hip spica (DHS) in 16, immediate hip spica (IHS) in 24, plate osteosynthesis (PO) in five, titanium elastic nailing (TEN) in five, and external fixation (EF) in one. The minimum hospital stay was two days, and the maximum 33 days (mean, 9.7 days). Malunion was the commonest complication. Conservative treatment is the preferred option for children under six years of age. It is cost-effective with minimal complication. The other treatment options are reserved for specific indication in older children. Diaphyseal fractures of the femur in children can be adequately managed non-operatively.

  4. Femoral fractures in children, is early interventional treatment beneficial?

    PubMed

    Sturdee, S W; Templeton, P A; Dahabreh, Z; Cullen, E; Giannoudis, P V

    2007-08-01

    A protocol of early intervention (flexible intramedullary nails, early hip spica, and external fixation) was started in 1999 and during a 3-year period there were 25 children who sustained a femoral shaft fracture (early intervention group). These were prospectively reviewed with a minimum follow up of 24 months (Range 24-35 months). A historical control group of 41 children was used. These children were injured between February 1996 and February 1999 and were retrospectively reviewed. They had traditional in patient treatments with either Gallows or Thomas splint traction (traditional treatment group). Over the 6-year period from 1996 to 2002 there were a total of 66 femoral shaft fractures in the study that presented to our hospital. The mean length of hospital stay was 29 nights in the traditional group and 10 nights in the early intervention group. This difference is significant (p<0.001). The malunion rate was slightly higher in the early active group at radiological union but most of these remodelled over the 2 years of follow up. The protocol of early intervention used in our institution, of flexible nails, early hip spica or external fixation depended on the age of the child, and has resulted in a shorter hospital stay for the children. This has benefits for the child, the family and the hospital.

  5. Combined use of Ilizarov external fixation and Papineau technique for septic pseudoarthrosis of the distal tibia in a patient with diabetes mellitus

    PubMed Central

    Koutsostathis, Stefanos D.; Lepetsos, Panagiotis; Polyzois, Vasilios D.; Pneumaticos, Spyros G.; Macheras, George A.

    2014-01-01

    The surgical treatment of open pilon fractures has a high complication rate especially in diabetic patients. In this article, we present a case of an infected tibial non-union after an open reduction and internal fixation in a diabetic patient, treated with Ilizarov external fixation combined with Papineau technique. Combined use of external fixation and Papineau technique can provide an alternative option for the treatment of septic pseudoarthrosis of the distal tibia. PMID:24563728

  6. Hydrogen fracture toughness tester completion

    SciTech Connect

    Morgan, Michael J.

    2015-09-30

    The Hydrogen Fracture Toughness Tester (HFTT) is a mechanical testing machine designed for conducting fracture mechanics tests on materials in high-pressure hydrogen gas. The tester is needed for evaluating the effects of hydrogen on the cracking properties of tritium reservoir materials. It consists of an Instron Model 8862 Electromechanical Test Frame; an Autoclave Engineering Pressure Vessel, an Electric Potential Drop Crack Length Measurement System, associated computer control and data acquisition systems, and a high-pressure hydrogen gas manifold and handling system.

  7. Gene Therapy for Fracture Repair

    DTIC Science & Technology

    2003-12-01

    relative transgene expression efficiencies for the MLV-based and lentiviral-based vectors, the Enhanced Green Fluorescent Protein (EGFP) was used as...for both Cy3 and Cy5 2,-15i Hybridized to to Aigilent Rat -s 2-- Gene Chip - iGnTrr. . tea 2 ug universal RNAw silx sl59 (?es) Cy310-0 (control) 1...fractures were also examined at sacrifice for evidence of fibrosis due to irritation or migration of the stabilizing pin. None was observed and the fracture

  8. Dynamic fracture of heterogeneous materials

    SciTech Connect

    Stout, M.G.; Liu, C.; Addessio, F.L.; Williams, T.O.; Bennett, J.G.; Haberman, K.S.; Asay, B.W.

    1998-12-31

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this project was to investigate the fundamental aspects of the process of dynamic fracture propagation in heterogeneous materials. The work focused on three important, but poorly understood, aspects of dynamic fracture for materials with a heterogeneous microstructure. These were: the appropriateness of using a single-parameter asymptotic analysis to describe dynamic crack-tip deformation fields, the temperature rises at the tip and on the flanks of a running crack, and the constitutive modeling of damage initiation and accumulation.

  9. Fracture - An Unforgiving Failure Mode

    NASA Technical Reports Server (NTRS)

    Goodin, James Ronald

    2006-01-01

    During the 2005 Conference for the Advancement for Space Safety, after a typical presentation of safety tools, a Russian in the audience simply asked, "How does that affect the hardware?" Having participated in several International System Safety Conferences, I recalled that most attention is dedicated to safety tools and little, if any, to hardware. The intent of this paper on the hazard of fracture and failure modes associated with fracture is my attempt to draw attention to the grass roots of system safety - improving hardware robustness and resilience.

  10. Probabilistic Simulation for Nanocomposite Fracture

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.

    2010-01-01

    A unique probabilistic theory is described to predict the uniaxial strengths and fracture properties of nanocomposites. The simulation is based on composite micromechanics with progressive substructuring down to a nanoscale slice of a nanofiber where all the governing equations are formulated. These equations have been programmed in a computer code. That computer code is used to simulate uniaxial strengths and fracture of a nanofiber laminate. The results are presented graphically and discussed with respect to their practical significance. These results show smooth distributions from low probability to high.

  11. Creep and fracture of a model yoghurt

    NASA Astrophysics Data System (ADS)

    Manneville, Sebastien; Leocmach, Mathieu; Perge, Christophe; Divoux, Thibaut

    2014-11-01

    Biomaterials such as protein or polysaccharide gels are known to behave qualitatively as soft solids and to rupture under an external load. Combining optical and ultrasonic imaging to shear rheology we show that the failure scenario of a model yoghurt, namely a casein gel, is reminiscent of brittle solids: after a primary creep regime characterized by a macroscopically homogeneous deformation and a power-law behavior which exponent is fully accounted for by linear viscoelasticity, fractures nucleate and grow logarithmically perpendicularly to shear, up to the sudden rupture of the gel. A single equation accounting for those two successive processes nicely captures the full rheological response. The failure time follows a decreasing power-law with the applied shear stress, similar to the Basquin law of fatigue for solids. These results are in excellent agreement with recent fiber-bundle models that include damage accumulation on elastic fibers and exemplify protein gels as model, brittle-like soft solids. Work funded by the European Research Council under Grant Agreement No. 258803.

  12. Incidence of hip fracture in southeastern Norway

    PubMed Central

    Reikerås, O.

    2006-01-01

    The incidence of hip fracture has been studied extensively, but there is still some doubt whether the age-specific incidence is increasing. The proportion of trochanteric fractures has varied and has also been said to be increasing. We studied data on 1,730 prospectively registered cases from 1998–2003 and computed age- and gender-specific incidence rates for intracapsular and trochanteric fractures. The incidence of hip fracture for women over 50 years was 1,263 and for men 452 per 100,000. The proportion of trochanteric fractures was 38% for women and 41% for men. There was no significant difference in the proportion of trochanteric fractures either between or within the genders, and the proportion did not exceed 50% in any age group. These findings confirm the high incidence of hip fracture in Norway but do not indicate any increase. The proportion of trochanteric fractures also seems to be stable. PMID:17033761

  13. Fractures of the Jaw and Midface

    MedlinePlus

    ... eye examination is done. Treatment Treatment of specific fractures, which may include surgery If people suspect their jaw is fractured, they should go to the emergency department immediately. If swelling or bleeding begins to close the breathing passages, doctors may ...

  14. Multiscale Multifunctional Progressive Fracture of Composite Structures

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Minnetyan, L.

    2012-01-01

    A new approach is described for evaluating fracture in composite structures. This approach is independent of classical fracture mechanics parameters like fracture toughness. It relies on computational simulation and is programmed in a stand-alone integrated computer code. It is multiscale, multifunctional because it includes composite mechanics for the composite behavior and finite element analysis for predicting the structural response. It contains seven modules; layered composite mechanics (micro, macro, laminate), finite element, updating scheme, local fracture, global fracture, stress based failure modes, and fracture progression. The computer code is called CODSTRAN (Composite Durability Structural ANalysis). It is used in the present paper to evaluate the global fracture of four composite shell problems and one composite built-up structure. Results show that the composite shells. Global fracture is enhanced when internal pressure is combined with shear loads. The old reference denotes that nothing has been added to this comprehensive report since then.

  15. [Vertical fractures: apropos of 2 clinical cases].

    PubMed

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

    1991-01-01

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

  16. [Iatrogenic evolutive skull fracture (author's transl)].

    PubMed

    Villarejo, F; Pascual Castroviejo, I; Dabdoub, C; Bordes, M; Jover, P

    1977-03-01

    A case of growing skull fracture secondary to a maxilofacial operation is reported. Frequency, clinical symptoms, phisiopathology and treatment of growing skull fractures are reviewed and the rarity of the iatrogenic mechanism is stressed.

  17. Sensitivity of the active fracture model parameter to fracture network orientation and injection scenarios

    NASA Astrophysics Data System (ADS)

    Başağaoğlu, Hakan; Succi, Sauro; Manepally, Chandrika; Fedors, Randall; Wyrick, Danielle Y.

    2009-09-01

    Active fractures refer to the portions of unsaturated, connected fractures that actively conduct water. The active fracture model parameter accounts for the reduction in the number of fractures carrying water and in the fracture-matrix interface area in field-scale simulations of flow and transport in unsaturated fractured rocks. One example includes the numerical analyses of the fault test results at the Yucca Mountain site, Nevada (USA). In such applications, the active fracture model parameter is commonly used as a calibration parameter without relating it to fracture network orientations and infiltration rates. A two-dimensional, multiphase lattice-Boltzmann model was used in this study to investigate the sensitivity of the active fracture model parameter to fracture network orientation and injection scenarios for an unsaturated, variable dipping, and geometrically simple fracture network. The active fracture model parameter differed by as much as 0.11-0.44 when the effects of fracture network orientation, injection rate, and injection mode were included in the simulations. Hence, the numerical results suggest that the sensitivity of the active fracture model parameter to fracture network orientation, injection rates, and injection modes should be explored at the field-scale to strengthen the technical basis and range of applicability of the active fracture model.

  18. [Treatment of hip fractures in elderly patients].

    PubMed

    Hack, Juliana; Bliemel, Christopher; Ruchholtz, Steffen; Bücking, Benjamin

    2015-04-01

    Hip fractures are among the most common fractures in elderly people. The annual number of femoral fractures is even expected to increase because of an aging society. Due to the high number of comorbidities, there are special challenges in treating geriatric hip fracture patients, which require a multidisciplinary management. This includes surgical treatment allowing full weight bearing in the immediate postoperative period, osteoporosis treatment and falls prevention as well as an early ortho-geriatric rehabilitation program.

  19. Fluid-driven fracture in poroelastic medium

    NASA Astrophysics Data System (ADS)

    Kovalyshen, Yevhen

    This research deals with an analysis of the problem of a fluid-driven fracture propagating through a poroelastic medium. Formulation of such model of an hydraulic fracture is at the cross-road of four classical disciplines of engineering mechanics: lubrication theory, filtration theory, fracture mechanics, and poroelasticity, which includes both elasticity and diffusion. The resulting mathematical model consists of a set of non-linear integro-differential history-dependent equations with singular behaviour at the moving fracture front. The main contribution of this research is a detailed study of the large-scale 3D diffusion around the fracture and its associated poroelastic effects on fracture propagation. The study hinges on scaling and asymptotic analyses. To understand the behavior of the solution in the tip region, we study a semi-infinite fracture propagating at a constant velocity. We show that, in contrast to the classical case of the Carter's leak-off model (1D diffusion), the tip region of a finite fracture cannot, in general, be modeled by a semi-infinite fracture when 3D diffusion takes place. Moreover, 3D diffusion does not permit separation of the problem into two regions: the tip and the global fracture. We restrict our study of the fracture propagation to an investigation of two limiting cases: zero viscosity and zero toughness. We show that large-scale 3D diffusion and its associated poroelastic effects can significantly affect the fracture evolution. In particular, we observe a significant increase of the net fracturing fluid pressure compared to the case of 1D diffusion due to the porous medium dilation. Another consequence of 3D diffusion is the possibility of fracture arrest. Indeed, the fracture stops propagating at large time, when the fracturing fluid injection rate is balanced by the leak-off rate at pressure below the critical propagation pressure.

  20. Minimally invasive osteosynthesis technique for articular fractures.

    PubMed

    Beale, Brian S; Cole, Grayson

    2012-09-01

    Articular fractures require accurate reduction and rigid stabilization to decrease the chance of osteoarthritis and joint dysfunction. Articular fractures have been traditionally repaired by arthrotomy and internal fixation. Recently, minimally invasive techniques have been introduced to treat articular fractures, reducing patient morbidity and improving the accuracy of reduction. A variety of techniques, including distraction, radiographic imaging, and arthroscopy, are used with the minimally invasive osteosynthesis technique of articular fractures to achieve a successful repair and outcome.