Sample records for stress fracture incidence

  1. Acetabular stress fractures in military endurance athletes and recruits: incidence and MRI and scintigraphic findings

    Williams, T.R. [Portsmouth Naval Medical Center, Radiology Department, Charette Health Care Center, Portsmouth, VA (United States); Puckett, M.L.; Shin, A.Y.; Gorman, J.D. [Naval Medical Center San Diego, Radiology Department, San Diego, CA (United States); Denison, G. [US Naval Hospital Guam (United States)


    Objective: To evaluate the incidence and the MRI and scintigraphic appearance of acetabular stress (fatigue) fractures in military endurance athletes and recruits. Design and patients: One hundred and seventy-eight active duty military endurance trainees with a history of activity-related hip pain were evaluated by both MRI and bone scan over a 2-year period. Patients in the study ranged in age from 17 to 45 years. They had hip pain related to activity and had plain radiographs of the hip and pelvis that were interpreted as normal or equivocal. The study was originally designed to evaluate the MRI and scintigraphic appearance of femoral neck stress fractures. Patients had scintigraphy and a limited MRI examination (coronal imaging only) within 48 h of the bone scan. Twelve patients demonstrated imaging findings compatible with acetabular stress fractures. Results: Stress fractures are common in endurance athletes and in military populations; however, stress fracture of the acetabulum is uncommon. Twelve of 178 patients (6.7%) in our study had imaging findings consistent with acetabular stress fractures. Two patterns were identified. Seven of the 12 (58%) patients had acetabular roof stress fractures. In this group, two cases of bilateral acetabular roof stress fractures were identified, one with a synchronous tensile sided femoral neck stress fracture. The remaining five of 12 (42%) patients had anterior column stress fractures, rarely occurring in isolation, and almost always occurring with inferior pubic ramus stress fracture (4 of 5, or 80%). One case of bilateral anterior column stress fractures was identified without additional sites of injury. Conclusions: Stress fractures are commonplace in military populations, especially endurance trainees. Acetabular stress fractures are rare and therefore unrecognized, but do occur and may be a cause for activity-related hip pain in a small percentage of military endurance athletes and recruits. (orig.)

  2. Incidence and Time to Return to Training for Stress Fractures during Military Basic Training

    Alexander M. Wood


    Full Text Available Currently, little is known about the length of time required to rehabilitate patients from stress fractures and their return to preinjury level of physical activity. Previous studies have looked at the return to sport in athletes, in a general population, where rehabilitation is not as controlled as within a captive military population. In this study, a longitudinal prospective epidemiological database was assessed to determine the incidence of stress fractures and the time taken to rehabilitate recruits to preinjury stage of training. Findings demonstrated a background prevalence of 5% stress fractures in Royal Marine training; femoral and tibial stress fractures take 21.1 weeks to return to training with metatarsal stress fractures being the most common injury taking 12.2 weeks. Rehabilitation from stress fractures accounts for 814 weeks of recruit rehabilitation time per annum. Stress fracture incidence is still common in military training; despite this stress fracture recovery times remain constant and represent a significant interruption in training. It takes on average 5 weeks after exercise specific training has restarted to reenter training at a preinjury level, regardless of which bone has a stress fracture. Further research into their prevention, treatment, and rehabilitation is required to help reduce these burdens.

  3. Stress Fractures

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

  4. High Serum 25-hydroxyvitamin D is Associated with Low Incidence of Stress Fractures


    of Family and Preventive Medicine, School of Medicine, University of California, San Diego, La Jolla, California 3 Osteoporosis Research (p 0.01) (9). Amenorrhea and age older than 25 years were also predictors of increased risk of stress fracture, while history of exercise was... exercise were independently associated with risk of fractures (9). In this study, it was not possible to include amenorrhea and exercise history (prior to

  5. Metatarsal stress fractures - aftercare

    ... page: // 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 ...

  6. Stress fractures in runners.

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


    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.

  7. Incidence and epidemiology of tibial shaft fractures

    Larsen, Peter; Elsøe, Rasmus; Hansen, Sandra Hope


    Introduction: The literature lacks recent population-based epidemiology studies of the incidence, trauma mechanism and fracture classification of tibial shaft fractures. The purpose of this study was to provide up-to-date information on the incidence of tibial shaft fractures in a large...... and complete population and report the distribution of fracture classification, trauma mechanism and patient baseline demographics. Methods: Retrospective reviews of clinical and radiological records. Results: A total of 196 patients were treated for 198 tibial shaft fractures in the years 2009 and 2010....... The mean age at time of fracture was 38.5 (21.2SD) years. The incidence of tibial shaft fracture was 16.9/100,000/year. Males have the highest incidence of 21.5/100,000/year and present with the highest frequency between the age of 10 and 20, whereas women have a frequency of 12.3/100,000/year and have...

  8. Female athlete triad and stress fractures.

    Feingold, David; Hame, Sharon L


    Stress fractures are a common occurrence in athletes, and the incidence of stress fractures in female Division 1 collegiate athletes is double that of men. Hormonal influences on bone and bone morphology may influence the risk for fracture. A high level of suspicion and special imaging procedures allow for accurate diagnosis of these fractures. In stress fractures that are associated with the female athlete triad, addressing the three aspects of the triad--eating disorders, amenorrhea, and osteoporosis--are critical for successful treatment. Preparticipation screening for the presence of signs of the female athlete triad by monitoring weight, energy level, menstrual cycles, and bone mineral density may help to prevent the occurrence of stress fractures in this population.


    Đivo Ban


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

  10. Incidence and Epidemiology of Patellar Fractures

    Larsen, Peter; Court-Brown, Charles M; Vedel, Julie Odgaard;


    The literature lacks large-scale, up-to-date, population-based epidemiology studies on the incidence of patellar fractures based on complete populations. The purpose of this study was to provide up-to-date information concerning the incidence of patellar fractures in a large and complete population...

  11. Stress fractures in the lower extremity

    Berger, Ferco H. [Academic Medical Center, University of Amsterdam, Department of Radiology, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Jonge, Milko C. de [Academic Medical Center, University of Amsterdam, Department of Radiology, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Maas, Mario [Academic Medical Center, University of Amsterdam, Department of Radiology, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands)]. E-mail:


    Stress fractures are fatigue injuries of bone usually caused by changes in training regimen in the population of military recruits and both professional and recreational athletes. Raised levels of sporting activity in today's population and refined imaging technologies have caused a rise in reported incidence of stress fractures in the past decades, now making up more than 10% of cases in a typical sports medicine practice. Background information (including etiology, epidemiology, clinical presentation and treatment and prevention) as well as state of the art imaging of stress fractures will be discussed to increase awareness amongst radiologists, providing the tools to play an important role in diagnosis and prognosis of stress fractures. Specific fracture sites in the lower extremity will be addressed, covering the far majority of stress fracture incidence. Proper communication between treating physician, physical therapist and radiologist is needed to obtain a high index of suspicion for this easily overlooked entity. Radiographs are not reliable for detection of stress fractures and radiologist should not falsely be comforted by them, which could result in delayed diagnosis and possibly permanent consequences for the patient. Although radiographs are mandatory to rule out differentials, they should be followed through when negative, preferably by magnetic resonance imaging (MRI), as this technique has proven to be superior to bone scintigraphy. CT can be beneficial in a limited number of patients, but should not be used routinely.

  12. Discontinuation of denosumab and associated fracture incidence

    Brown, Jacques P; Roux, Christian; Törring, Ove;


    Osteoporosis is a chronic disease and requires long-term treatment with pharmacologic therapy to ensure sustained anti-fracture benefit. Denosumab reduced the risk for new vertebral, nonvertebral, and hip fractures over 36 months in the FREEDOM trial. While discontinuation of denosumab has been...... associated with transient increases in bone remodeling and declines in bone mineral density (BMD), the effect on fracture risk during treatment cessation is not as well characterized. To understand the fracture incidence between treatment groups after cessation of investigational product, we evaluated...... of 797 subjects (470 placebo, 327 denosumab), who were evaluable during the off-treatment period, showed similar baseline characteristics for age, prevalent fracture, and lumbar spine and total hip BMD T-scores. During treatment, more placebo-treated subjects as compared with denosumab-treated subjects...

  13. Phalangeal bone mineral density predicts incident fractures

    Friis-Holmberg, Teresa; Brixen, Kim; Rubin, Katrine Hass


    This prospective study investigates the use of phalangeal bone mineral density (BMD) in predicting fractures in a cohort (15,542) who underwent a BMD scan. In both women and men, a decrease in BMD was associated with an increased risk of fracture when adjusted for age and prevalent fractures....... PURPOSE: The aim of this study was to evaluate the ability of a compact and portable scanner using radiographic absorptiometry (RA) to predict major osteoporotic fractures. METHODS: This prospective study included a cohort of 15,542 men and women aged 18-95 years, who underwent a BMD scan in Danish Health...... Examination Survey 2007-2008. BMD at the middle phalanges of the second, third and fourth digits of the non-dominant hand was measured using RA (Alara MetriScan®). These data were merged with information on incident fractures retrieved from the Danish National Patient Registry comprising the International...


    Sanda Dubravcic-Simunjak


    Full Text Available Figure skating is a physically demanding sport that requires a unique combination of artistic ability, speed, agility, flexibility and power. During the last decades not only the competitive schedule has become tougher, but after introduction of the new judging system in 2003, also more emphasis is put on difficult technical elements, jumps, steps and spins (ISU Rules, 2006. More studies about possible increasing prevalence of stress fractures in figure skaters and contributing factors are lacking (Dubravcic-Simunjak et al., 2003; Moran, 2000; Pecina et al., 1990. Therefore the aim of this study was to obtain data about the current stress fracture cumulative risk among elite junior and senior figure skaters, as well as possible factors that may contribute to stress fracture incidence. An anonymous questionnaire, divided into 5 sections, inquired about the prevalence of stress fracture were mailed and distributed to all 62 International Skating Union (ISU members by the ISU headquarters in Lausanne, Switzerland. The guidelines of the Helsinki declaration 2004 were followed. From the 644 skaters who received the questionnaire, 412 completed ones were returned from 110 female juniors (78 single skaters, 12 pair skaters and 20 ice dancers and 135 female seniors (97 single skaters, 16 pair skaters and 22 ice dancers and from 79 male juniors (47 single skaters, 12 pair skaters and 20 ice dancers and 88 male seniors (50 single skaters, 16 pair skaters and 22 ice dancers, coming from different ISU members. The response rate was 62% in females and 67% in males. The median age for female skaters was 16 years and for males 18 years (range 12-25 years. All participants started to skate between 3 and 6 years of age and started to compete in national and international competitions when they were between 5 and 7 years old. At the time of this analysis, they had been skating between 9 and 20 years.In females 41 (16.7%, and in males 25 (13.8% figure skaters

  15. Traumatic sternal fracture: Incidence, causes and CT features

    Kim, Hyo Weon; Kim, Young Tong; Jou, Sung Shick; Han, Jong Kyu; Bae, Won Kyung [Dept. of Radiology, Soonchunhyang University College of Medicine, Cheonan Hospital, Cheonan (Korea, Republic of)


    To evaluate the incidence of sternal fracture due to trauma, the CT features of sternal fractures, and the hospitalization period. The medical records and CT images of 755 patients who suffered trauma from January 2012 to August 2013 were analyzed retrospectively. We compared the incidence of sternal fracture due to various traumatic causes. We evaluated the location and shape of the sternal fracture on CT scans and the relationship between a sternal fracture and the hospitalization period. The incidence of sternal fracture was 9.27% (70/755) in all patients; 11.7% (53/453) due to a traffic accident (TA), and 5.63% (17/302) due to other causes. TA was the most frequent cause (75.71%) of a sternal fracture, fracture incidences after a TA differed by traumatic cause (p < 0.05). Among sternal fractures, the body was the most commonly involved (68.57%), one wall was limited (32.85%), and anteroposterior length increased (7.14%). Body fractures involving two or more segments included 33.33% of the cases. The hospitalization period was not related with sternal fracture (p = 0.30). Fracture was more frequent after a TA than due to other causes. Fracture incidences after a TA depended on the traumatic causes. Involvement of two or more segments and one wall-limitation were common among sternal fractures. Sternal fractures occurred even in slightly injured patients.

  16. Increasing incidence of hip fracture in Chiang Mai, Thailand.

    Wongtriratanachai, Prasit; Luevitoonvechkij, Sirichai; Songpatanasilp, Thawee; Sribunditkul, Siripoj; Leerapun, Taninnit; Phadungkiat, Sompant; Rojanasthien, Sattaya


    Hip fracture is a major health problem in Thailand. This study attempted to examine the incidence, related factors, and trends of hip fracture in Chiang Mai, Thailand. All hip fracture data among patients aged 50 yr or older were collected from hospitals in Chiang Mai, Thailand from August 1, 2006 to July 3, 2007. Data from the 1997 Chiang Mai hip fracture study were used for comparison. In the study period, 690 hip fractures were reported: 203 males and 487 females (male to female ratio was 1 to 2.4), with a mean age of 76.7 yr. The estimated cumulative incidence was 181.0 per 100,000, and the adjusted incidence was 253.3 (males: 135.9; females: 367.9). A simple fall was the most common mechanism (79%) of fracture, and 80% of the hip fractures occurred in patients aged 70 yr or older. The highest incidence of hip fracture was observed in patients older than 85 yr (1239). At 6 mo postfracture, most patients (61%) used a walking aid. Compared with the 1997 data, hip fracture incidence had increased by an average of 2% per yr, and the incidence of hip fracture had increased significantly from August 1, 2006 to July 31, 2007, especially in patients older than 75 yr. In patients older than 84 yr, the incidence increased by a factor of 2. Urgent strategies for the prevention and treatment of osteoporosis, and hence hip fracture, are needed.

  17. Pedicular stress fracture in the lumbar spine

    Chong, V.F.H.; Htoo, M.M. [Singapore General Hospital, Singapore, (Singapore). Department of Diagnostic Radiology


    Spondylolisthesis with or without spondylolysis is common in the lumbar spine. Associated fracture in the pedicle (`pediculolysis`) is unusual. The margins of pedicular stress fractures, like spondylolysis, usually appear sclerotic. A patient with a pedicular stress fracture with minimal marginal sclerosis suggesting an injury of recent onset is presented here. There was associated bilateral spondylolysis. The findings in this patient suggest that established pediculolysis probably represents a stress fracture that has failed to heal. (authors). 10 refs., 2 figs.

  18. The Epidemiology of Incident Fracture from Cradle to Senescence.

    Pasco, Julie A; Lane, Stephen E; Brennan-Olsen, Sharon L; Holloway, Kara L; Timney, Elizabeth N; Bucki-Smith, Gosia; Morse, Amelia G; Dobbins, Amelia G; Williams, Lana J; Hyde, Natalie K; Kotowicz, Mark A


    To reduce the burden of fracture, not only does bone fragility need to be addressed, but also injury prevention. Thus, fracture epidemiology irrespective of degree of trauma is informative. We aimed to determine age-and-sex-specific fracture incidence rates for the Barwon Statistical Division, Australia, 2006-2007. Using radiology reports, incident fractures were identified for 5342 males and 4512 females, with incidence of 210.4 (95 % CI 204.8, 216.2) and 160.0 (155.3, 164.7)/10,000/year, respectively. In females, spine (clinical vertebral), hip (proximal femoral) and distal forearm fractures demonstrated a pattern of stable incidence through early adult life, with an exponential increase beginning in postmenopausal years for fractures of the forearm followed by spine and hip. A similar pattern was observed for the pelvis, humerus, femur and patella. Distal forearm, humerus, other forearm and ankle fractures showed incidence peaks during childhood and adolescence. For males, age-related changes mimicked the female pattern for fractures of the spine, hip, ribs, pelvis and humerus. Incidence at these sites was generally lower for males, particularly among the elderly. A similar childhood-adolescent peak was seen for the distal forearm and humerus. For ankle fractures, there was an increase during childhood and adolescence but this extended into early adult life; in contrast to females, there were no further age-related increases. An adolescent-young adult peak incidence was observed for fractures of the face, clavicle, carpal bones, hand, fingers, foot and toe, without further age-related increases. Examining patterns of fracture provides the evidence base for monitoring temporal changes in fracture burden, and for identifying high-incidence groups to which fracture prevention strategies could be directed.

  19. Decreasing incidence of hip fracture in the Funen County, Denmark

    Nymark, Tine; Lauritsen, Jens; Ovesen, Ole


    Hip fracture incidence rates are high, and increase with increasing age. Previous studies have predicted a continued increase in both crude and age-standardized rates.......Hip fracture incidence rates are high, and increase with increasing age. Previous studies have predicted a continued increase in both crude and age-standardized rates....

  20. Clavicle fractures - incidence of supraclavicular nerve injury

    Pedro Jose Labronici


    Full Text Available OBJECTIVE: To analyze retrospectively 309 fractures in the clavicle and the relation with injury of the supraclavicular nerve after trauma. METHODS: It was analyzed 309 patients with 312 clavicle fractures. The Edinburgh classification was used. Four patients had fractures in the medial aspect of the clavicle, 33 in the lateral aspect and 272 in the diaphyseal aspect and three bilateral fractures. RESULTS: 255 patients were analyzed and five had paresthesia in the anterior aspect of the thorax. Four patients had type 2 B2 fracture and one type 2 B1 fracture. All patients showed spontaneous improvement, in the mean average of 3 months after the trauma. CONCLUSION: Clavicle fractures and/ or shoulder surgeries can injure the lateral, intermediary or medial branches of the supraclavicular nerve and cause alteration of sensibility in the anterior aspect of the thorax. Knowledge of the anatomy of the nerve branches helps avoid problems in this region.

  1. Interpretation of stress damage on fracture conductivity

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


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

  2. Thoracic kyphosis and rate of incident vertebral fractures: the Fracture Intervention Trial

    Vittinghoff, E.; Kado, D. M.; Lane, N. E.; Ensrud, K. E.; Shipp, K.


    Summary Biomechanical analyses support the theory that thoracic spine hyperkyphosis may increase risk of new vertebral fractures. While greater kyphosis was associated with an increased rate of incident vertebral fractures, our analysis does not show an independent association of kyphosis on incident fracture, after adjustment for prevalent vertebral fracture. Excessive kyphosis may still be a clinical marker for prevalent vertebral fracture. Introduction Biomechanical analyses suggest hyperkyphosis may increase risk of incident vertebral fracture by increasing the load on vertebral bodies during daily activities. We propose to assess the association of kyphosis with incident radiographic vertebral fracture. Methods We used data from the Fracture Intervention Trial among 3038 women 55–81 years of age with low bone mineral density (BMD). Baseline kyphosis angle was measured using a Debrunner kyphometer. Vertebral fractures were assessed at baseline and follow-up from lateral radiographs of the thoracic and lumbar spine. We used Poisson models to estimate the independent association of kyphosis with incident fracture, controlling for age and femoral neck BMD. Results Mean baseline kyphosis was 48° (SD = 12) (range 7–83). At baseline, 962 (32 %) participants had a prevalent fracture. There were 221 incident fractures over a median of 4 years. At baseline, prevalent fracture was associated with 3.7° greater average kyphosis (95 % CI 2.8–4.6, p < 0.0005), adjusting for age and femoral neck BMD. Before adjusting for prevalent fracture, each 10° greater kyphosis was associated with 22 % increase (95 % CI 8–38 %, p = 0.001) in annualized rate of new radiographic vertebral fracture, adjusting for age and femoral neck BMD. After additional adjustment for prevalent fracture, estimated increased annualized rate was attenuated and no longer significant, 8 % per 10° kyphosis (95 % CI −4 to 22 %, p = 0.18). Conclusions While greater kyphosis increased the rate of

  3. An Epidemiological Study on Pattern and Incidence of Mandibular Fractures

    Subodh S. Natu


    Full Text Available Mandible is the second most common facial fracture. There has been a significant increase in the number of cases in recent years with the advent of fast moving automobiles. Mandibular fractures constitute a substantial proportion of maxillofacial trauma cases in Lucknow. This study was undertaken to study mandibular fractures clinicoradiologically with an aim to calculate incidence and study pattern and the commonest site of fractures in population in and around Lucknow. Patient presenting with history of trauma at various centers of maxillofacial surgery in and around Lucknow were included in this study. Detailed case history was recorded followed by thorough clinical examination, and radiological interpretation was done for establishing the diagnosis and the data obtained was analyzed statistically. Out of 66 patients with mandibular fractures, highest percentage was found in 21–30 years of age with male predominance. Road traffic accidents were the most common cause of fracture with parasymphysis being commonest site. Commonest combination was parasymphysis with subcondyle. There was no gender bias in etiology with number of fracture sites. The incidence and causes of mandibular fracture reflect trauma patterns within the community and can provide a guide to the design of programs geared toward prevention and treatment.

  4. Incidence and socioeconomic burden of hip fractures in Italy

    A. Angeli


    Full Text Available Objectives: The aim of this study was to evaluate the trend of the incidence and costs of hip fractures in Italy. Methods: The incidence of hip fractures after 45 years of age in both females and males during the years 1999-2002 was obtained by analyzing the Italian Ministry of Health national hospitalization database, according to the diagnosis codes of International Classification of Diseases, Clinical Modification, 9° edition (IDC-9-CM that indicate femoral fracture. We have computed all direct costs sustained by the National Health Service for hospitalization and treatment of hip fractures on the basis of the value of the Diagnosis Related Groups (DRG referring to hip fractures. The expenses of rehabilitation and indirect expenses were based on estimates. Results: In 2002, more than 86,000 hip fractures were registered in Italy in male and female patients over 45 years old, with 9% progression compared to 1999; 77% were female and 80% were over 75 years of age. In 2002 the direct costs of hospitalization, in the patients over 65 years alone, were almost 400 milion euros, with an increase of 15% as compared to 1999. Considering also estimated rehabilitation costs, social aid and indirect costs, we estimate that hip fractures due to age-related osteoporosis created over a billion euros in expenses in 2002. Conclusions: Preventive intervention regarding the risk of hip fracture in elderly patients is urgent.

  5. Prevalence and Cost of Subsequent Fractures Among U.S. Patients with an Incident Fracture.

    Weaver, Jessica; Sajjan, Shiva; Lewiecki, E Michael; Harris, Steven T; Marvos, Panagiotis


    The prevalence and cost of subsequent fractures among patients with an incident fracture are not well defined. To assess the prevalence of, and costs associated with, subsequent fractures in the year after an incident fracture. This was a retrospective claims database analysis using data from Humana Medicare Advantage claims (Medicare group) and Optum Insight Clinformatics Data Mart commercial claims (commercial group). Patients included in the study had a claim for a qualifying fracture occurring between January 2008 and December 2013 (index fracture), were continuously enrolled in the health plan for ≥ 1 year before and after the index fracture, and were aged ≥ 65 years in the Medicare group or ≥ 50 years in the commercial group at the time of the index fracture. Subsequent fractures were identified by ICD-9-CM codes and were defined as the second fracture occurring ≥ 3 to ≤ 12 months after the index fracture (≥ 6 to ≤ 12 months for fractures at the same site as the index fracture). Rates of subsequent fractures were calculated as the number of patients who had a subsequent fracture divided by the total sample size. After propensity matching of demographic and clinical variables, we determined the total medical and pharmacy costs accrued within 1 year of the index fracture by patients with and without a subsequent fracture. Health care costs were compared between patients with and without a subsequent fracture using McNemar's test. A total of 45,603 patients were included in the Medicare group, and 54,145 patients were included in the commercial group. In the Medicare group, 7,604 (16.7%) patients experienced a subsequent fracture. The proportion of patients with a subsequent fracture was highest among patients with multiple index fractures (26.2%, n = 905), followed by those with hip (25.5%, n = 1,280) and vertebral (20.2%, n = 1,908) index fractures. In the commercial group, 6,256 (11.6%) patients experienced a subsequent fracture. The proportion

  6. Transverse Stress Fracture of the Proximal Patella

    Atsumi, Satoru; Arai, Yuji; Kato, Ko; Nishimura, Akinobu; Nakazora, Shigeto; Nakagawa, Shuji; Ikoma, Kazuya; Fujiwara, Hiroyoshi; Sudo, Akihiro; Kubo, Toshikazu


    Abstract Among stress fractures associated with sports activities, patellar stress fracture is rare. Regarding patella stress fractures, so far only distal transverse or lateral longitudinal fractures have been reported, but there are no reports of transverse fractures occurring in the proximal patella. We describe an extremely rare case of transverse stress fracture of proximal patella in a 9-year-old athlete. A 9-year old boy, who participated in sports (sprints and Kendo) presented with left knee pain without any external injury. In plain radiographs, a fracture line was observed in the proximal 1/3 of the left patella, and a patella stress fracture was diagnosed. For treatment, because 7 months of conservative therapy showed no improvement, internal fixation was carried out using Acutrak screws, and bone union was thus achieved. Three months after the operation, he was able to return to his previous level of athletic sports activity. Regarding the mechanism of onset, it is believed that the causes are longitudinal traction force and patellofemoral contact pressure. On the other hand, the contact region of the patella with the femur changes with the flexion angle of the knee. In the current case, the fracture occurred at a site where the patella was in contact with the femur at a flexion angle of >90°, so it is believed that it occurred as a clinical condition from being subjected to repeated longitudinal traction force and patellofemoral contact pressure at a flexion angle of >90°, during the sports activities of sprints and Kendo. The nonunion of the transverse stress fracture of his proximal patella was successfully treated with internal fixation using Acutrak screws. PMID:26871789

  7. Incidence of Hip Fractures among Iranian Elderly Population

    A Moayyeri


    Full Text Available Hip fracture, the most dramatic complication of osteoporosis, constitutes a serious health problem of the elderly, with great socioeconomic consequences. Hip fracture epidemiology has been studied by many investigators. Until now, there are no reported studies in Iran regarding this issue. We studied hip fractures that occurred in Iran in 2003 and compared the findings with those of other countries. Data used were obtained from the Iranian Multicenter Study on Accidental Injuries, a large-scale population-based study conducted in 9 provinces across the country. The study was conducted by the Ministry of Health and Medical Education and continued for 135 days (4.5 months in all centers, beginning in a date between 15 June 2003 and 15 July 2003 for each center. A total of 1482 new cases of hip fracture (1079 male, 403 female were recorded during the study period. The crude annual incidence of hip fracture (per 100000 person-years was 59.8 in men and 23.5 in women. The incidence rates increased exponentially after the age of 60 in both genders and nearly tripled after each decade. In comparison with hip fracture incidence rates of other countries, Iranian rates are considerably lower than other Asian, European, and American countries. The reasons for this low incidence rate remain uncertain. With increase in life span, rapid economic development and aging of the population, hip fracture will become a major health problem in Iran and studies are needed to increase awareness of osteoporosis and to monitor the epidemiology of hip fractures.

  8. Rare stress fracture: longitudinal fracture of the femur.

    Pérez González, M; Velázquez Fragua, P; López Miralles, E; Abad Moretón, M M


    42-year-old man with pain in the posterolateral region of the right knee that began while he was running. Initially, it was diagnosed by magnetic resonance (MR) as a possible aggressive process (osteosarcoma or Ewing's sarcoma) but with computed tomography it was noted a cortical hypodense linear longitudinal image with a continuous, homogeneous and solid periosteal reaction without clear soft tissue mass that in this patient suggest a longitudinal distal femoral fatigue stress fracture. This type of fracture at this location is very rare. Stress fractures are entities that can be confused with an agressive process. MR iscurrently the most sensitive and specific imaging method for its diagnosis. Copyright © 2017 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. Critical incident stress debriefing in health care.

    Freehill, K M


    Transport team professionals have unique responsibilities and are exposed to powerful demands. They cannot avoid incidents that pose personal threats to their own emotional well being. Contact with dead or severely ill or injured children, for example, can be detrimental to the caregiver. Discussions called debriefings held after these critical incidents can decrease acute and delayed stress reactions.

  10. Incidence of mandibular fractures in Eastern part of Libya.

    Elgehani, Rafa-Abdelsalam; Orafi, Maraai-Idris


    The objective of this retrospective study is to evaluate the incidence of mandibular fractures in the eastern part of Libya and to present our experience in treating this type of facial fracture. We analyzed factors such as the incidence of age, sex, time distribution, cause and site of the fracture and the associated injuries in 493 patients presenting a total of 666 mandibular fractures. These patients were treated at Al-Jala Trauma Hospital, Benghazi-Libya between 2000 and 2006. The results were obtained from 432 males and 61 females, for which the ages ranged from 8 months to 72 years. The maximum number of the patients was recorded in 2004, and the busiest month was May. The most common cause of fracture was road traffic accidents and the most common site was the parasymphysis. Among those treated with closed reduction were 241 patients, whereas 201 patients were treated with open reduction. In conclusion, we found that the results were similar to most studies from developing countries and were in contrast to other studies. This may be due factors such as geography, socioeconomic trends, religion, road traffic legislation and seasons, which differ from one country to another. The period during which there was an embargo in Libya also appears to have affected the results.

  11. Transverse Stress Fracture of the Proximal Patella: A Case Report

    Atsumi, Satoru; Arai, Yuji; Kato, Ko; Nishimura, Akinobu; Nakazora, Shigeto; Nakagawa, Shuji; Ikoma, Kazuya; Fujiwara, Hiroyoshi; Sudo, Akihiro; Kubo, Toshikazu


    .... Regarding patella stress fractures, so far only distal transverse or lateral longitudinal fractures have been reported, but there are no reports of transverse fractures occurring in the proximal patella...

  12. Lumbar facet stress fracture in a ballet dancer.

    Fehlandt, A F; Micheli, L J


    A frequent cause of back pain in athletes and dancers is stress injury to the posterior vertebral elements. Stress fractures affect the pars interarticularis and, rarely, other vertebral regions. The authors present their experience with the diagnosis and treatment of a fourth lumbar inferior articular facet stress fracture in a ballerina in this brief report and discuss the literature concerning posterior element stress fractures.

  13. The importance of previous fracture site on osteoporosis diagnosis and incident fractures in women.

    Morin, Suzanne N; Lix, Lisa M; Leslie, William D


    Previous fracture increases the risk of subsequent fractures regardless of the site of the initial fracture. Fracture risk assessment tools have been developed to guide clinical management; however, no discrimination is made as to the site of the prior fracture. Our objective was to determine which sites of previous nontraumatic fractures are most strongly associated with a diagnosis of osteoporosis, defined by a bone mineral density (BMD) T-score of ≤ -2.5 at the femoral neck, and an incident major osteoporotic fracture. Using administrative health databases, we conducted a retrospective historical cohort study of 39,991 women age 45 years and older who had BMD testing with dual-energy X-ray absorptiometry (DXA). Logistic regression and Cox proportional multivariate models were used to test the association of previous fracture site with risk of osteoporosis and incident fractures. Clinical fractures at the following sites were strongly and independently associated with higher risk of an osteoporotic femoral neck T-score after adjustment for age: hip (odds ratio [OR], 3.58; 95% confidence interval [CI], 3.04-4.21), pelvis (OR, 2.23; 95% CI, 1.66-3.0), spine (OR, 2.16; 95% CI, 1.77-2.62), and humerus (OR, 1.74; 95% CI, 1.49-2.02). Cox proportional hazards models, with adjustment for age and femoral neck BMD, showed the greatest increase in risk for a major osteoporotic fracture for women who had sustained previous fractures of the spine (hazard ratio [HR], 2.08; 95% CI, 1.72-2.53), humerus (HR, 1.70; 95% CI, 1.44-2.01), patella (HR, 1.54; 95% CI, 1.10-2.18), and pelvis (HR, 1.45; 95% CI, 1.04-2.02). In summary, our results confirm that nontraumatic fractures in women are associated with osteoporosis at the femoral neck and that the site of previous fracture impacts on future osteoporotic fracture risk, independent of BMD.

  14. Stress fractures: definition, diagnosis and treatment☆

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


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

  15. High incidence of chronic pain following surgery for pelvic fracture

    Meyhoff, Christian Sylvest; Thomsen, Camilla Højland; Rasmussen, Lars Simon


    OBJECTIVES: To determine the incidence of chronic pain after surgery for pelvic fracture using a strict definition and measures of intensity and health-related quality of life. METHODS: In April 2004, a questionnaire was sent to 221 patients who underwent surgery for pelvic fracture in the period...... 1996 to 2000. Chronic pain was defined as pain at present that related back to the pelvic fracture and was not a consequence of other disease. Health-related quality of life was measured using the 15D questionnaire. RESULTS: The response rate was 72.9% after a median follow-up of 5.6 years. Chronic...... pain was seen in 48.4% (95% confidence interval, 40.7%-56.2%). These patients had a combination of somatic nociceptive, visceral nociceptive, and neuropathic pain and had significantly lower health-related quality of life. Also, the use of opioids (14.1% vs. 4.8%) and nonsteroidal anti...

  16. Fractures and stresses in Bone Spring sandstones

    Lorenz, J.C.; Warpinski, N.R.; Sattler, A.R.; Northrop, D.A.


    This project is a collaboration between Sandia National Laboratories and Harvey E. Yates Company being conducted under the auspices of the Oil Recovery Technology Partnership. The project seeks to apply perspectives related to the effects of natural fractures, stress, and sedimentology to the simulation and production of low-permeability gas reservoirs to low-permeability oil reservoirs as typified by the Bone Spring sandstones of the Permian Basin, southeast New Mexico. This report presents the results and analysis obtained in 1989 from 233 ft of oriented core, comprehensive suite of logs, various in situ stress measurements, and detailed well tests conducted in conjunction with the drilling of two development wells. Natural fractures were observed in core and logs in the interbed carbonates, but there was no direct evidence of fractures in the sandstones. However, production tests of the sandstones indicated permeabilities and behavior typical of a dual porosity reservoir. A general northeast trend for the maximum principal horizontal stress was observed in an elastic strain recovery measurements and in strikes of drilling-induced fractures; this direction is subparallel to the principal fracture trend observed in the interbed carbonates. Many of the results presented are believed to be new information for the Bone Spring sandstones. 57 figs., 18 tabs.

  17. The area moment of inertia of the tibia: a risk factor for stress fractures.

    Milgrom, C; Giladi, M; Simkin, A; Rand, N; Kedem, R; Kashtan, H; Stein, M; Gomori, M


    In a prospective study of stress fractures among Israeli infantry recruits, the area moment of inertia of the tibia was found to have a statistically significant correlation with the incidence of tibial, femoral and total stress fractures. Recruits with "low" area moments of inertia of the tibia were found to have higher stress fracture morbidity than those with "high" area moments of inertia. The best correlation was obtained when the area moment of inertia was calculated about the AP axis of bending at a cross-sectional level corresponding to the narrowest tibial width on lateral X-rays, a point which is at the distal quarter of the tibia. This finding indicates that bending forces about the approximate AP axis are an important causal factor for tibial and many other stress fractures. The bone's bending strength, or ability to resist bending moments, as measured by the area moment of inertia, helps determine risk to stress fracture.

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

    Schwartz, Frederik; Heerfordt, Ida Marie


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

  19. 78 FR 38878 - Critical Incident Stress Plans


    ... implement critical incident stress plans. As discussed in detail below, FRA reviewed the applicable science... productivity: Two reasons employee assistance programs make good business cents. Annals of the American... should be handled by each railroad on an individual basis, as the applicable science does not appear...

  20. MRI examination of stress fractures. Kernspintomographische Untersuchungen von Stressfrakturen

    Yousry, T.; Fink, U.; Breitner, S.; Stelzer, A.; Tiling, R.; Staebler, A. (Klinikum Grosshadern, Muenchen (Germany, F.R.). Radiologische Klinik und Poliklinik)


    Stress fractures can represent a diagnostic problem especially in their differentiation from bone tumours. 6 patients with 7 lesions were examined. MRI visualised the stress fractures and established the diagnosis of stress fracture vs. tumour in 6 cases. In the seventh, biopsy having been performed, a tumour was ruled out. MRI is more sensitive than radiography in the detection of stress fractures, showing the characteristic changes earlier. MRI, being a very sensitive method in the diagnosis of stress fractures and a reliable one in their differentiation from bone tumours, can be applied in cases of unusual clinical course and difficult radiological diagnosis prior to biopsy. (orig.).

  1. Changing incidence and residual lifetime risk of common osteoporosis-related fractures

    Lauritzen, J B; Schwarz, Peter; Lund, B;


    1735 fractures of the distal radius, 747 fractures of the proximal humerus, 878 cervical and 635 trochanteric hip fractures were included. In men 273 cervical and 232 trochanteric hip fractures were included. The fractures were registered during the period 1976 to 1984 and changes in age......-specific incidence were calculated (chi-squared test for linear trend; p-values less than 0.05 were considered significant). On the basis of life tables and population background data, the lifetime risk was estimated. The incidence of cervical hip fractures in women aged 60-89 years decreased significantly (p ....05) during the observation period, while no significant decrease was found in the incidence of trochanteric fractures. No significant changes in incidence were observed in women with radial or humeral fractures, or in men with hip fractures. A women 60 years old with a life expectancy of 81 years had...

  2. [Stress fracture after changing to barefoot running].

    Christensen, Mikkel


    Barefoot running is increasing in popularity but little is known about the implications in respect to injuries. It has been proposed that barefoot running is associated with a decrease in running injuries as it represents a more natural way of running. A 50-year-old runner with a weekly running distance of 50 km presented suffering from a stress fracture of the second metatarsal after six weeks of intensive barefoot running.

  3. Incidence of Deformation and Fracture of Twisted File Adaptive Instruments after Repeated Clinical Use

    Gambarini, Gianluca; Piasecki, Lucila; Miccoli, Gabriele; Di Giorgio, Gianni; Carneiro, Everdan; Al-Sudani, Dina; Testarelli, Luca


    ABSTRACT Objectives The aim of the present study was to investigate the incidence of deformation and fracture of twisted file adaptive nickel-titanium instruments after repeated clinical use and to identify and check whether the three instruments within the small/medium sequence showed similar or different visible signs of metal fatigue. Material and Methods One-hundred twenty twisted file adaptive (TFA) packs were collected after clinically used to prepare three molars and were inspected for deformations and fracture. Results The overall incidence of deformation was 22.2%, which was not evenly distributed within the instruments: 15% for small/medium (SM)1 (n = 18), 38.33% for SM2 (n = 46) and 13.33% for the SM3 instruments (n = 16). The defect rate of SM2 instruments was statistically higher than the other two (P < 0.001). The fracture rate was 0.83% (n = 3), being two SM2 instruments and one SM3. Conclusions It was observed a very low defect rate after clinical use of twisted file adaptive rotary instruments. The untwisting of flutes was significantly more frequent than fracture, which might act as prevention for breakage. The results highlight the fact that clinicians should be aware that instruments within a sequence might be differently subjected to intracanal stress. PMID:28154749

  4. Age Related Incidence and Early Outcomes of Hip Fractures: A Prospective Cohort Study of 1177 patients

    Shenoy Ravikiran; Eranki Vivek; Pillai Anand; Hadidi Mahar


    Abstract Introduction Associated with the increase in the aging population, there is an increase in the incidence of hip fractures worldwide. Outcome following such fractures is affected by age of the patient. This study aims to assess the incidence and early outcome of hip fractures, comparing between different age groups. Methods Data of hip fractures collected over a period of five years was analysed. Patients were divided into three groups, group A (patients under the age of 64), group B ...

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

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


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

  6. Atypical stress-avulsion fracture of the Lisfranc joint complex.

    O'Neill, Barry J


    Antiphospholipid syndrome and systemic erythematosus have been associated with metatarsal stress fractures. Stress fractures of the Lisfranc joint complex are uncommon injuries but have been reported to occur most frequently in ballet dancers. We present a case of an avulsion fracture of the Lisfranc joint complex that occurred spontaneously. We have reviewed the association between systemic conditions and metatarsal fractures and proposed a series of hypothetical pathological events that may have contributed to this unusual injury.

  7. Incidence of fractures in patients with multiple sclerosis: the Danish National Health Registers

    Bazelier, Marloes T; de Vries, Frank; Bentzen, Joan


    Background: Patients with multiple sclerosis (MS) are potentially at high risk of fracture due to falls and osteoporosis. Objective: To estimate incidence rates of fractures in MS patients, stratified by fracture type, sex and age, and to compare these rates with controls. Methods: The case...... (controls). Incidence rates of fracture were estimated as the number of fractures per 1000 person-years. Incidence rate ratios (IRRs) were calculated by dividing fracture rates in MS patients by fracture rates in controls. Results: Among patients with MS, the incidence rate of any fracture yielded 22.8 per...... 1000 person-years. The IRR of any fracture between MS patients and controls was 1.40 (95% CI 1.33-1.46). In particular, IRRs of tibia fracture (3.36 [2.75-4.11]), femur fracture (6.66 [5.06-8.76]) and hip fracture (3.20 [2.83-3.62]) were elevated in MS patients versus controls. Conclusion: Fractures...

  8. Impact of Stress on Anomalous Transport in Fractured Rock

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


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

  9. Effects of ball sports on future risk of stress fracture in runners.

    Fredericson, Michael; Ngo, Jessica; Cobb, Kristin


    To evaluate whether playing ball sports during childhood and adolescence is associated with the risk of stress fractures in runners later in life. Retrospective cohort study. National track and field championships, held at Stanford University. One hundred fifty-six elite female and 118 elite male distance runners, age 18 to 44 years. A 1-page questionnaire was used to collect data regarding ages during which athletes played basketball and soccer, as well as other important covariates and outcomes. Athletes reported the ages when stress fractures occurred. Time to event was defined as the number of years from beginning competitive running to the first stress fracture or to current age, if no fracture had occurred. In both men and women, playing ball sports in youth correlated with reduced stress fracture incidence later in life by almost half, controlling for possible confounders. In men, each additional year of playing ball sports conferred a 13% decreased incidence of stress fracture (adjusted hazard ratio [HR] and 95% confidence interval, 0.87 [0.79-0.95]. Among women with regular menses, the HR for each additional year of playing ball sports was similar: 0.87 (0.75-1.00); however, there was no effect of length of time played among women with irregular menses (HR, 1.03 [0.92-1.16]). In men, younger ages of playing ball sports conferred more protection against stress fractures (HR for each 1-year-older age at first exposure, 1.29 [1.14, 1.45]). Runners who participate during childhood and adolescence in ball sports may develop bone with greater and more symmetrically distributed bone mass, and with enhanced protection from future stress fractures.

  10. Secular trends in fracture incidence in the UK between 1990 and 2012

    van der Velde, R Y; Wyers, C E; Curtis, E M; Geusens, P P M M; van den Bergh, J P W; de Vries, F; Cooper, C; van Staa, T P; Harvey, N C


    We studied sex-specific incidence rates in a population 50 years or older in the UK. In the period of 1990-2012, the overall rate of fracture did not change, but there were marked secular alterations in the rates of individual fracture types, particularly hip and spine fractures in the elderly. INTR

  11. The incidence of symptomatic venous thromboembolism following hip fractures with or without surgery in Taiwan

    Cheng-Han Lee


    Conclusions: The incidence of symptomatic VTE after hip fractures is low in Taiwan. Patients rarely received pharmacological thromboprophylaxis following hip fractures. Universal thromboprophylaxis for patients experiencing hip fractures was not necessary in Taiwan, but it should be considered in high-risk populations.

  12. Secular trends in fracture incidence in the UK between 1990 and 2012.

    van der Velde, R Y; Wyers, C E; Curtis, E M; Geusens, P P M M; van den Bergh, J P W; de Vries, F; Cooper, C; van Staa, T P; Harvey, N C


    We studied sex-specific incidence rates in a population 50 years or older in the UK. In the period of 1990-2012, the overall rate of fracture did not change, but there were marked secular alterations in the rates of individual fracture types, particularly hip and spine fractures in the elderly.

  13. Modelling stress-dependent permeability in fractured rock including effects of propagating and bending fractures

    Latham, J.P.; Xiang, J.; Belayneh, M.; Nick, H.M.; Tsang, C.F.; Blunt, M.J.


    The influence of in-situ stresses on flow processes in fractured rock is investigated using a novel modelling approach. The combined finite-discrete element method (FEMDEM) is used to model the deformation of a fractured rock mass. The fracture wall displacements and aperture changes are modelled in

  14. Evaluating the Risk of a Fifth Metatarsal Stress Fracture by Measuring the Serum 25-Hydroxyvitamin D Levels.

    Shimasaki, Yu; Nagao, Masashi; Miyamori, Takayuki; Aoba, Yukihiro; Fukushi, Norifumi; Saita, Yoshitomo; Ikeda, Hiroshi; Kim, Sung-Gon; Nozawa, Masahiko; Kaneko, Kazuo; Yoshimura, Masafumi


    The fifth metatarsal bone is a common site of stress fractures in soccer athletes. Although several endocrine risk factors for stress fractures have been proposed, the endocrine risks for fifth metatarsal (5-MT) stress fractures have not been evaluated. To evaluate the endocrine risks of fifth metatarsal stress fractures, we conducted a cumulative case-control study. The present study included 37 athletes, of which 18 had a history of a zone 2 or zone 3 fifth metatarsal stress fracture and 19 controls. We analyzed serum 25-hydroxyvitamin D (25-OHD), serum parathyroid hormone (PTH), as well as biochemical markers of bone turnover by univariate or multivariate analyses. Logistic regression analyses adjusted for multiple confounders revealed that insufficient serum 25-OHD levels less than 30 ng/mL (odds ratio [OR], 23.3), higher serum PTH levels (OR, 1.01), or higher serum bone-specific isoform of alkaline phosphatase levels (OR, 1.10) rather than serum tartrate-resistant acid phosphatase 5b were associated with statistically significantly increased odds of 5-MT stress fractures. A postestimation calculation demonstrated that 25-OHD levels of 10 and 20 ng/mL were associated with 5.1 and 2.9 times greater odds for 5-MT stress fractures, respectively. 25-OHD insufficiency was associated with an increased incidence of 5-MT stress fractures. This insight may be useful for intervening to prevent 5-MT stress fractures. Level III, case-control study. © The Author(s) 2015.




    During a 16-year period, 256 second hip fractures were found in 3898 persons 40 years of age and older who had a previous hip fracture. Ninety-two percent of the second fractures were contra-lateral, and 68% of these were the same type as the first. Thus, 62% of the femoral neck and 72......% of the trochanteric fractures were preceded by a contra-lateral fracture of the same type. The mean interval between fractures was 3.3 years, and there was no significant difference between genders or among fracture types. The risk of the first fracture was 1.6 per 1000 men per year and 3.6 per 1000 women......, and for the second fracture 15 per 1000 men per year and 22 per 1000 women. This increase was highly significant for both genders, especially for men....

  16. Stress Fracture and Nonunion of Coronoid Process in a Gymnast

    T. Hetling


    Full Text Available Background. Gymnasts have high mechanical loading forces of up to 14 times body weight. Overuse lesions are typical in wrists and stress fractures in the olecranon, while isolated fractures of the coronoid process are uncommon. We present a case of retraumatized nonunion stress fracture of the ulnar coronoid process. Case Description. A 19-year-old gymnast presented with elbow pain after training. Imaging confirmed an old fracture of the coronoid process. We describe a 6-month multiphase return to competition rehabilitation program, which allowed him to compete pain-freely. Literature Review. Acute and overuse injuries in gymnasts are known but no nonunion of the coronoid process has been described before. Only one case of stress fracture of coronoid process in a gymnast was reported. Purpose and Clinical Relevance. We could successfully and conservatively return to sport a reactivated nonunion of a stress fracture of the coronoid process.


    A.S. Grader; D. Elsworth; P.M. Halleck; F. Alvarado; A. Alajmi; Z. Karpyn; N. Mohammed; S. Al-Enezi


    The main objectives of this project are to quantify the changes in fracture porosity and multiphase transport properties as a function of confining stress. These changes will be integrated into conceptual and numerical models that will improve our ability to predict and optimize fluid transport in fractured system. This report details our progress on: (a) developing the direct experimental measurements of fracture aperture and topology and fluid occupancy using high-resolution x-ray micro-tomography, (b) quantifying the effect of confining stress on the distribution of fracture aperture, and (c) characterization of shear fractures and their impact on multi-phase flow. The three-dimensional surface that describes the large-scale structure of the fracture in the porous medium can be determined using x-ray micro-tomography with significant accuracy. Several fractures have been scanned and the fracture aperture maps have been extracted. The success of the mapping of fracture aperture was followed by measuring the occupancy of the fracture by two immiscible phases, water and decane, and water and kerosene. The distribution of fracture aperture depends on the effective confining stress on the nature of the rock and the type and distribution of the asperities that keep the fracture open. Fracture apertures at different confining stresses were obtained by micro-tomography covering a range of about two thousand psig. Initial analysis of the data shows a significant aperture closure with increase in effective confining stress. Visual descriptions of the process are shown in the report while detailed analysis of the behavior of the distribution of fracture aperture is in progress. Both extensional and shear fractures are being considered. The initial multi-phase flow tests were done in extensional fractures. Several rock samples with induced shear fracture are being studies, and some of the new results are presented in this report. These samples are being scanned in order to

  18. Spallation and fracture resulting from reflected and intersecting stress waves.

    Kinslow, R.


    Discussion of the effects of stress waves produced in solid by explosions or high-velocity impacts. These waves rebound from free surfaces in the form of tensile waves that are capable of causing internal fractures or spallation of the material. The high-speed framing camera is shown to be an important tool for observing the stress waves and fracture in transparent targets, and its photographs provide valuable information on the mechanics of fracture.


    Ran Yanovich


    Full Text Available To investigate the association of polymorphisms within candidate genes which we hypothesized may contribute to stress fracture predisposition, a case-control, cross- sectional study design was employed. Genotyping 268 Single Nucleotide Polymorphisms- SNPs within 17 genes in 385 Israeli young male and female recruits (182 with and 203 without stress fractures. Twenty-five polymorphisms within 9 genes (NR3C1, ANKH, VDR, ROR2, CALCR, IL6, COL1A2, CBG, and LRP4 showed statistically significant differences (p < 0.05 in the distribution between stress fracture cases and non stress fracture controls. Seventeen genetic variants were associated with an increased stress fracture risk, and eight variants with a decreased stress fracture risk. None of the SNP associations remained significant after correcting for multiple comparisons (false discovery rate- FDR. Our findings suggest that genes may be involved in stress fracture pathogenesis. Specifically, the CALCR and the VDR genes are intriguing candidates. The putative involvement of these genes in stress fracture predisposition requires analysis of more cases and controls and sequencing the relevant genomic regions, in order to define the specific gene mutations

  20. Association of serum uric acid and incident nonspine fractures in elderly men: the Osteoporotic Fractures in Men (MrOS) study.

    Lane, Nancy E; Parimi, Neeta; Lui, Li-Yung; Wise, Barton L; Yao, Wei; Lay, Yu-An Evan; Cawthon, Peggy M; Orwoll, Eric


    Uric acid (UA) is produced from purines by the enzyme xanthine oxidase, and elevated levels may cause arthritis and kidney stones. Conversely, UA also appears to function as an antioxidant and may protect against the oxidative stress associated with aging and disease. We performed a prospective fracture case-cohort study to understand the relation of UA and fracture risk in older men enrolled in the Osteoporotic Fractures in Men (MrOS) study. In the cohort of 5994 men aged 65 years and older attending the baseline MrOS examination, we evaluated a subgroup 1680 men in a case-cohort study design. The analytic group included 387 men with incident nonspine fractures (73 hip) and a random sample of 1383. Serum UA was measured in baseline serum samples. Modified proportional hazards models that account for case-cohort study design were used to estimate the relative hazards (RH) of hip and nonspine fracture in men for serum UA. Models were adjusted for age, race, clinic site, body mass index, vitamin D, parathyroid hormone, walking speed, Physical Activity Scale for the Elderly (PASE) score, frailty, and total. Subjects with incident nonspine fractures were older, had lower total hip bone mineral density (BMD), and higher serum phosphorus. There was an 18% decreased risk of nonspine fractures (95% confidence interval [CI] 0.71-0.93; p = 0.003) per 1 SD increase of baseline serum and 34% decreased risk of nonspine fractures in quartile 4 of UA versus quartiles 1, 2, and 3 (95% CI 0.49-0.89; p = 0.028) compared with nonfracture cases after multivariate adjustment. Hip fractures were not significantly associated with UA. Total hip BMD was significantly higher in the group of men with high UA levels compared with lower UA levels and increased linearly across quartiles of UA after multivariate adjustment (p for trend = 0.002). In summary, higher serum UA levels were associated with a reduction in risk of incident nonspine fractures but not hip fractures and higher hip BMD.

  1. Postpartum Sacral Stress Fracture: An Atypical Case Report

    Andrea Speziali


    Full Text Available Sacral stress fractures are common in elderly people. However, sacral stress fracture should be always screened in the differential diagnoses of low back pain during the postpartum period. We present a case of sacral fracture in a thirty-six-year-old woman with low back pain and severe right buttock pain two days after cesarean section delivery of a 3.9 Kg baby. The diagnosis was confirmed by MRI and CT scan, while X-ray was unable to detect the fracture. Contribution of mechanical factors during the cesarean section is not a reasonable cause of sacral fracture. Pregnancy and lactation could be risk factors for sacral stress fracture even in atraumatic delivery such as cesarean section. Our patient had no risk factors for osteoporosis except for pregnancy and lactation. Transient or focal osteoporosis is challenging to assess and it cannot be ruled out even if serum test and mineral density are within the normal range.

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

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


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

  3. Improvements in hip fracture incidence counterbalanced by the rise of other fracture types: data from Spain 2000-2010.

    Cirera, Eva; Pérez, Katherine; Santamariña-Rubio, Elena; Novoa, Ana M; Olabarria, Marta


    In recent years, the incidence of injury in older people has increased. The aim of this study is to address the hypothesis that this increase is due to an increase in the incidence of some injuries that, while less common than hip fractures, are sufficient jointly to counteract the decrease or stabilisation in hip fracture rates observed in most countries. We performed a descriptive study of trends using data from the National Hospital Discharge Register. We included individuals 65 years and older who were discharged from a Spanish hospital during the period 2000-2010 with at least one injury diagnosis in the primary diagnosis field on the discharge form. The dependent variables were the following injury groups, classified using the Barell Matrix: hip fracture, shoulder and upper arm fractures, forearm and elbow fractures, thoracic fractures, lower leg and ankle fractures, and TBI type 1 internal injury. Incidence rates were calculated per 100,000 inhabitants (data from National Statistics Institute) and stratified by sex and age group. Trends, in terms of Annual Percent Change (APC), were assessed using Poisson Regression with discharge year as the independent variable. Hip fracture continues to be the most important injury type in older people. Thoracic fractures and TBI internal injuries are more common in men, while fractures in the upper extremities are more common in women. All injuries increased in frequency with age, except lower leg and ankle fractures, which decreased. While a secular decreasing trend in hip fracture was noted, the incidences of fractures of the shoulder and upper arm, forearm and elbow, and lower leg and ankle, as well as of TBI type 1 internal injuries have increased steadily. Although hip fracture continue to be the most common type of injury in older people, this study has allowed identifying other types of injury that are becoming increasingly common. These trends are driving paradigm changes in the burden of injuries requiring

  4. Incidence and characteristics of distal radius fractures in a southern Swedish region

    Atroshi Isam


    Full Text Available Abstract Background The incidence of distal radius fracture has increased substantially during the last 50 years according to several studies that estimated the overall incidence in various general populations. The incidence of fracture classified according to severity has not been well documented. The aim of this population-based study was to estimate the overall and type-specific incidence rates of distal radius fracture in a representative population in southern Sweden. Methods During 2001, all persons older than 18 years with acute distal radius fracture in the southern Swedish region of Northeastern Scania were prospectively recorded. A radiologist classified the fractures according to the AO system and measured volar tilt and ulnar variance. A fracture with volar tilt outside a range of -5° to 20° and/or ulnar variance of 2 mm or greater was defined as displaced. Results 335 persons with acute distal radius fracture were recorded during the 1-year period. The overall incidence rate was 26 (95% confidence interval 23–29 per 10,000 person-years. Among women the incidence rate increased rapidly from the age of 50 and reached a peak of 119 per 10,000 person-years in women 80 years and older. The incidence rate among women 50 to 79 years old (56 per 10,000 person-years was lower than that reported in previous studies of similar populations. Among men the incidence rate was low until the age of 80 years and older when it increased to 28 per 10,000 person-years. Fractures classified as AO type A comprised about 80% of the fractures in women and 64% in men. Almost two-thirds of all fractures were displaced and among men and women 80 years and older more than 80% of the fractures were displaced. Conclusion The incidence rate of distal radius fracture in women 50 to 79 years old was lower than previously reported, which may indicate declining incidence in this group. In both sexes, the incidence was highest in the age group of 80 years and older

  5. Prediction of incident hip fracture with the estimated femoral strength by finite element analysis of DXA Scans in the study of osteoporotic fractures.

    Yang, Lang; Palermo, Lisa; Black, Dennis M; Eastell, Richard


    A bone fractures only when loaded beyond its strength. The purpose of this study was to determine the association of femoral strength, as estimated by finite element (FE) analysis of dual-energy X-ray absorptiometry (DXA) scans, with incident hip fracture in comparison to hip bone mineral density (BMD), Fracture Risk Assessment Tool (FRAX), and hip structure analysis (HSA) variables. This prospective case-cohort study included a random sample of 1941 women and 668 incident hip fracture cases (295 in the random sample) during a mean ± SD follow-up of 12.8 ± 5.7 years from the Study of Osteoporotic Fractures (n = 7860 community-dwelling women ≥67 years of age). We analyzed the baseline DXA scans (Hologic 1000) of the hip using a validated plane-stress, linear-elastic finite element (FE) model of the proximal femur and estimated the femoral strength during a simulated sideways fall. Cox regression accounting for the case-cohort design assessed the association of estimated femoral strength with hip fracture. The age-body mass index (BMI)-adjusted hazard ratio (HR) per SD decrease for estimated strength (2.21; 95% CI, 1.95-2.50) was greater than that for total hip (TH) BMD (1.86; 95% CI, 1.67-2.08; p  0.05), FRAX scores (range, 1.32-1.68; p hip BMD or FRAX scores. The association of estimated strength with incident hip fracture was strong (Harrell's C index 0.770), significantly better than TH BMD (0.759; p  0.05). Similar findings were obtained for intracapsular and extracapsular fractures. In conclusion, the estimated femoral strength from FE analysis of DXA scans is an independent predictor and performs at least as well as FN BMD in predicting incident hip fracture in postmenopausal women. © 2014 American Society for Bone and Mineral Research.

  6. Effect of ground stress on hydraulic fracturing of methane well

    DU Chun-zhi; MAO Xian-biao; MIAO Xie-xing; WANG Peng


    Most of the coal reservoirs in China are of low-permeability, so hydraulic fracturing is widely used to improve the permeability in the extraction of gas by ground drilling. The ground stress around the well was analyzed by using theory of elasticity. The pressure when the well fractured is formulated and the effect of ground stress on pressure is discussed. The effect of ground-stress-differences on hydraulic fracturing was analyzed by using the numerical software RFPA2D-Flow in reference to the tectonic stress in Jincheng coal area. The results show that: 1) the position where initial fracture appears is random and fracture branches emerge when the fractures expand if ground stresses in any two directions within a horizontal plane are equal; 2) otherwise, the fractures expand in general along the direction of maximum ground stress and the critical pressure decreases with increasing ground-stress-differences and 3) the preferred well-disposition pattern is diamond shaped. The preferred well spacing is 250 m×300 m. This study can provide a reference for the design of wells.

  7. A comparison of hip fracture incidence rates among elderly in Sweden by latitude and sunlight exposure.

    Nilson, Finn; Moniruzzaman, Syed; Andersson, Ragnar


    Research has shown that hip fracture risk increases with latitude; hypothetically due to reduced sunlight exposure and its effect on bone quality. Sweden, with large differences in latitude and UV radiation, is ideal to study in order to analyse the association between latitude and UV radiation on age- and sex-specific hip fracture rates among elderly. Aggregated (2006-2008) age- and sex-specific hip fracture data was obtained for each Swedish municipality as well as the municipality's latitudinal coordinates and aggregated (2006-2008) UV radiation levels. Pearson correlations were calculated between hip fracture incidence rates, latitude and UV radiation. Independent t tests were calculated on tertile-categorized latitudinal data in order to investigate the difference in hip fracture risk between these categories. Statistically significant correlations were seen in all groups between hip fracture incidence rates and latitude as well as UV radiation. The independent t tests showed that this correlation was mainly due to high incidence rates in high latitude municipalities. Statistically significant correlations are seen between hip fracture incidence rates and latitude as well as UV radiation in Sweden and the northern parts of Sweden have an increased risk of hip fractures compared to the middle and southern parts. To our knowledge this is the first study using a national discharge register that shows this relationship and provides a starting point for further research to investigate why populations in northern Sweden have a higher risk of hip fractures compared to other Swedish regions.

  8. Epidemiology of Pelvic Fractures in Germany: Considerably High Incidence Rates among Older People.

    Andrich, Silke; Haastert, Burkhard; Neuhaus, Elke; Neidert, Kathrin; Arend, Werner; Ohmann, Christian; Grebe, Jürgen; Vogt, Andreas; Jungbluth, Pascal; Rösler, Grit; Windolf, Joachim; Icks, Andrea


    Epidemiological data about pelvic fractures are limited. Until today, most studies only analyzed inpatient data. The purpose of this study was to estimate incidence rates of pelvic fractures in the German population aged 60 years or older, based on outpatient and inpatient data. We conducted a retrospective population-based observational study based on routine data from a large health insurance company in Germany. Age and sex-specific incidence rates of first fractures between 2008 and 2011 were calculated. We also standardized incidence rates with respect to age and sex in the German population. Multiple Poisson regression models were used to evaluate the association between the risk of first pelvic fracture as outcome and sex, age, calendar year and region as independent variables. The total number of patients with a first pelvic fracture corresponded to 8,041 and during the study period 5,978 insured persons needed inpatient treatment. Overall, the standardized incidence rate of all first pelvic fractures was 22.4 [95% CI 22.0-22.9] per 10,000 person-years, and the standardized incidence rate of inpatient treated fractures 16.5 [16.1-16.9]. Our adjusted regression analysis confirmed a significant sex (RR 2.38 [2.23-2.55], p year (higher risk in later years compared to 2008, p = 0.0162) and first fracture risk and a further significant association with region (RR 0.92 [0.87-0.98], p = 0.006, Westfalen-Lippe as reference). The observed incidences are considerably higher than incidences described in the international literature, even if only inpatient treated pelvic fractures are regarded. Besides which, non-inclusion of outpatient data means that a relevant proportion of pelvic fractures are not taken into account. Prevention of low energy trauma among older people remains an important issue.

  9. Critical incident stress debriefing: implications for best practice.

    Mitchell, Ann M; Sakraida, Teresa J; Kameg, Kirstyn


    Critical incidents disrupt people's lives by creating strong emotional reactions, which may range from normal stress reactions to post-traumatic stress disorders. Critical incident stress debriefing (CISD) has been used since 1983 as a component of Critical Incident Stress Management. The processes are intended to help individuals manage their normal stress reactions to abnormal events. Although used extensively, research findings to date yield mixed results. Meta-analyses of research studies are reviewed to identify the methods, results, strengths, and weaknesses of the studies that can be used for evidence-based practice.

  10. Measurements of residual stress in fracture mechanics coupons

    Prime, Michael B [Los Alamos National Laboratory; Hill, Michael R [U.C. DAVIS; Nav Dalen, John E [HILL ENGINEERING


    This paper describes measurements of residual stress in coupons used for fracture mechanics testing. The primary objective of the measurements is to quantify the distribution of residual stress acting to open (and/or close) the crack across the crack plane. The slitting method and the contour method are two destructive residual stress measurement methods particularly capable of addressing that objective, and these were applied to measure residual stress in a set of identically prepared compact tension (C(T)) coupons. Comparison of the results of the two measurement methods provides some useful observations. Results from fracture mechanics tests of residual stress bearing coupons and fracture analysis, based on linear superposition of applied and residual stresses, show consistent behavior of coupons having various levels of residual stress.




    Full Text Available The aim of this study was to determine the incidence, etiology of mandibular fractures among different age and sex group to determine the frequency of anatomical distribution of fracture site. The study was conducted in the Department of ENT in associatio n with Department of Dentistry, CIMS, and Bilaspur. We included total 100 patients particularly with mandibular fracture and associated maxillofacial injuries. These patients were treated at Chhattisgarh Institute of Medical Sciences, Bilaspur from May 201 2 to April 2015. Among these 100 patients the most common cause of mandib le fracture is Road Traffic Acc idents with parasymphysis fracture as most common site. Incident of Mandibular fracture is mainly observed in male patients with 20 – 30 years of age group

  12. Atypical femoral neck stress fracture in a marathon runner: a case report and literature review.


    BACKGROUND: Femoral neck stress fractures are relatively rare and may present as sports-related injuries. The presentation is variable, and prompt diagnosis facilitates the earliest return to pre-morbid functional activity levels. Delayed detection may precipitate femoral non-union or avascular necrosis, resulting in long-term functional deficit. AIMS: We present the case of a basicervical femoral neck stress fracture occurring in a 23-year-old marathon runner. The pathophysiology and practical management issues related to this unusual injury pattern are discussed. CONCLUSION: The growing interest in amateur athletic activities should raise the index of suspicion for stress fractures of the femoral neck in healthy adults with atypical hip pain. Increased levels of patient education and physician awareness can reduce the incidence of long-term morbidity in cases of this unusual sports-related injury.

  13. Stress Fractures of the Foot and Ankle in Athletes

    Mayer, Stephanie W.; Joyner, Patrick W.; Almekinders, Louis C.; Parekh, Selene G.


    Context: Stress fractures of the foot and ankle are a common problem encountered by athletes of all levels and ages. These injuries can be difficult to diagnose and may be initially evaluated by all levels of medical personnel. Clinical suspicion should be raised with certain history and physical examination findings. Evidence Acquisition: Scientific and review articles were searched through PubMed (1930-2012) with search terms including stress fractures and 1 of the following: foot ankle, medial malleolus, lateral malleolus, calcaneus, talus, metatarsal, cuboid, cuneiform, sesamoid, or athlete. Study Design: Clinical review. Level of Evidence: Level 5. Results: Stress fractures of the foot and ankle can be divided into low and high risk based upon their propensity to heal without complication. A wide variety of nonoperative strategies are employed based on the duration of symptoms, type of fracture, and patient factors, such as activity type, desire to return to sport, and compliance. Operative management has proven superior in several high-risk types of stress fractures. Evidence on pharmacotherapy and physiologic therapy such as bone stimulators is evolving. Conclusion: A high index of suspicion for stress fractures is appropriate in many high-risk groups of athletes with lower extremity pain. Proper and timely work-up and treatment is successful in returning these athletes to sport in many cases. Low-risk stress fracture generally requires only activity modification while high-risk stress fracture necessitates more aggressive intervention. The specific treatment of these injuries varies with the location of the stress fracture and the goals of the patient. PMID:25364480

  14. Unusual exercise-related stress fractures. Two case reports

    Fink-Bennett, D.M.; Benson, M.T.


    We describe two unusual exercise-related stress fractures, one in the sacroiliac joint of a long distance runner, the other in the body of the scapulae of an above-knee amputee. Each were detected on a 2-hour delay bone scan. To our knowledge, neither have been described scintigraphically. The bilateral scapular fracture is an unreported entity, and the fractured SI joint is a very uncommon site for an overuse injury.

  15. Transverse Stress Fracture of the Proximal Patella: A Case Report.

    Atsumi, Satoru; Arai, Yuji; Kato, Ko; Nishimura, Akinobu; Nakazora, Shigeto; Nakagawa, Shuji; Ikoma, Kazuya; Fujiwara, Hiroyoshi; Sudo, Akihiro; Kubo, Toshikazu


    Among stress fractures associated with sports activities, patellar stress fracture is rare. Regarding patella stress fractures, so far only distal transverse or lateral longitudinal fractures have been reported, but there are no reports of transverse fractures occurring in the proximal patella. We describe an extremely rare case of transverse stress fracture of proximal patella in a 9-year-old athlete.A 9-year old boy, who participated in sports (sprints and Kendo) presented with left knee pain without any external injury. In plain radiographs, a fracture line was observed in the proximal 1/3 of the left patella, and a patella stress fracture was diagnosed. For treatment, because 7 months of conservative therapy showed no improvement, internal fixation was carried out using Acutrak screws, and bone union was thus achieved. Three months after the operation, he was able to return to his previous level of athletic sports activity.Regarding the mechanism of onset, it is believed that the causes are longitudinal traction force and patellofemoral contact pressure. On the other hand, the contact region of the patella with the femur changes with the flexion angle of the knee. In the current case, the fracture occurred at a site where the patella was in contact with the femur at a flexion angle of >90°, so it is believed that it occurred as a clinical condition from being subjected to repeated longitudinal traction force and patellofemoral contact pressure at a flexion angle of >90°, during the sports activities of sprints and Kendo. The nonunion of the transverse stress fracture of his proximal patella was successfully treated with internal fixation using Acutrak screws.

  16. Longitudinal stress fracture of the femur: A rare presentation

    Bilreiro, Carlos; Bahia, Carla; Castro, Miguel Oliveira e


    We present the case of an 80 year old woman with hip pain, caused by a longitudinal femoral insufficiency stress fracture, depicted with radiographs, CT and MR. This type of fracture is very rare, with only a few cases reported. We conducted a literature review and compared the findings with the present case. PMID:27069976

  17. Medial supracondylar stress fracture in an adolescent pitcher

    Chang, Eric Y.; Chung, Christine B. [VA San Diego Healthcare System, San Diego, CA (United States); University of California, San Diego Medical Center, San Diego, CA (United States); Fronek, Jan [Scripps Healthcare, La Jolla, CA (United States)


    We report the occurrence of a medial supracondylar stress fracture in an adolescent pitcher. To our knowledge, this fracture has not been described in the literature, and awareness of this entity allows initiation of therapy and precludes further unnecessary work-up. The radiographic, computed tomography, and magnetic resonance imaging appearances are reviewed and the mechanism of injury is discussed. (orig.)

  18. Geographic Variation in Osteoporotic Hip Fracture Incidence: The Growing Importance of Asian Influences in Coming Decades

    D. K. Dhanwal


    Full Text Available Studies over the last few decades have demonstrated geographic variation in the incidence of hip fracture across continents and among different parts of the same region. This paper studies the epidemiology of hip fracture worldwide, with special emphasis on the geographic variation among Asian countries. Using the Pubmed database, keywords that were employed included hip fracture, incidence rate, geographic variation, osteoporosis, and epidemiology. Articles were chosen based on the basis of (1 focus: studies that were said to specifically focus on geographic variation in hip fracture from different continents with a focus on Asia; (2 language: studies that were in English; (3 methods: studies that used statistical tests to examine hip fracture incidence rates. The highest hip fracture rates are seen in Scandinavian countries and the US and the lowest in African countries. Fracture rates are intermediate in Asian populations. Among different ethnic populations, the highest fracture rates are seen in Caucasians and the lowest in blacks. There is also a north-south gradient, particularly in Europe, where more hip fractures occur in North Europe compared to the South.

  19. 3-D description of fracture surfaces and stress-sensitivity analysis for naturally fractured reservoirs

    Zhang, S.Q.; Jioa, D.; Meng, Y.F.; Fan, Y.


    Three kinds of reservoir cores (limestone, sandstone, and shale with natural fractures) were used to study the effect of morphology of fracture surfaces on stress sensitivity. The cores, obtained from the reservoirs with depths of 2170 to 2300 m, have fractures which are mated on a large scale, but unmated on a fine scale. A specially designed photoelectric scanner with a computer was used to describe the topography of the fracture surfaces. Then, theoretical analysis of the fracture closure was carried out based on the fracture topography generated. The scanning results show that the asperity has almost normal distributions for all three types of samples. For the tested samples, the fracture closure predicted by the elastic-contact theory is different from the laboratory measurements because plastic deformation of the aspirates plays an important role under the testing range of normal stresses. In this work, the traditionally used elastic-contact theory has been modified to better predict the stress sensitivity of reservoir fractures. Analysis shows that the standard deviation of the probability density function of asperity distribution has a great effect on the fracture closure rate.

  20. Lower thoracic rib stress fractures in baseball pitchers.

    Gerrie, Brayden J; Harris, Joshua D; Lintner, David M; McCulloch, Patrick C


    Stress fractures of the first rib on the dominant throwing side are well-described in baseball pitchers; however, lower thoracic rib fractures are not commonly recognized. While common in other sports such as rowing, there is scant literature on these injuries in baseball. Intercostal muscle strains are commonly diagnosed in baseball pitchers and have a nearly identical presentation but also a highly variable healing time. The diagnosis of a rib stress fracture can predict a more protracted recovery. This case series presents two collegiate baseball pitchers on one team during the same season who were originally diagnosed with intercostal muscle strains, which following magnetic resonance imaging (MRI) were found to have actually sustained lower thoracic rib stress fractures. The first sustained a stress fracture of the posterior aspect of the right 8th rib on the dominant arm side, while the second presented with a left-sided 10th rib stress fracture on the nondominant arm side. In both cases, MRI was used to visualize the fractures as plain radiographs are insensitive and commonly negative early in patient presentation. Patients were treated with activity modification, and symptomatic management for 4-6 weeks with a graduated return to throwing and competition by 8-10 weeks. The repetitive high stresses incurred by pitching may cause either dominant or nondominant rib stress fractures and this should be included in the differential diagnosis of thoracic injuries in throwers. It is especially important that athletic trainers and team physicians consider this diagnosis, as rib fractures may have a protracted course and delayed return to play. Additionally, using the appropriate imaging techniques to establish an accurate diagnosis can help inform return-to-play decisions, which have important practical applications in baseball, such as roster management and eligibility.

  1. MR semiology of stress fractures; Semiologie IRM des fractures de fatigue

    Boyer, B.; Cordoliani, Y.S.; Naudinat, E.; Sylvestre, A.; Pharaboz, C. [Hopital des Armees Begin, 94 - Saint-Mande (France)


    Nuclear Magnetic Resonance imaging can contribute to stress fractures diagnosis when it makes obvious the fracture line which signal is variable in function of site lesion. The importance of inflammatory reactions must not call the diagnosis in question again. 5 figs., 8 refs.

  2. Critical incident stress and challenges for the emergency workplace.

    Oster, N S; Doyle, C J


    A formal response to all levels of critical incidents that are potentially psychologically disturbing is needed. This response is needed for small-scale and large-scale incidents, such as natural or manmade disasters. Health care providers at all levels should be encouraged to participate in wellness programs and to understand workplace stressors. Critical incident stress debriefing teams have a valuable role in preventing posttraumatic stress disorder. Procedures for establishing response teams are presented, and future directions are discussed.

  3. Genetic predisposition for femoral neck stress fractures in military conscripts

    Barral Sandra; Sahi Timo; Ruohola Juha-Petri; Solovieva Svetlana; Pihlajamäki Harri; Hartikka Heini; Korvala Johanna; Ott Jürg; Ala-Kokko Leena; Männikkö Minna


    Abstract Background Stress fractures are a significant problem among athletes and soldiers and may result in devastating complications or even permanent handicap. Genetic factors may increase the risk, but no major susceptibility genes have been identified. The purpose of this study was to search for possible genetic factors predisposing military conscripts to femoral neck stress fractures. Results Eight genes involved in bone metabolism or pathology (COL1A1, COL1A2, OPG, ESR1, VDR, CTR, LRP5...

  4. Genetic predisposition for femoral neck stress fractures in military conscripts

    Barral Sandra


    Full Text Available Abstract Background Stress fractures are a significant problem among athletes and soldiers and may result in devastating complications or even permanent handicap. Genetic factors may increase the risk, but no major susceptibility genes have been identified. The purpose of this study was to search for possible genetic factors predisposing military conscripts to femoral neck stress fractures. Results Eight genes involved in bone metabolism or pathology (COL1A1, COL1A2, OPG, ESR1, VDR, CTR, LRP5, IL-6 were examined in 72 military conscripts with a femoral neck stress fracture and 120 controls. The risk of femoral neck stress fracture was significantly higher in subjects with low weight and body mass index (BMI. An interaction between the CTR (rs1801197 minor allele C and the VDR C-A haplotype was observed, and subjects lacking the C allele in CTR and/or the C-A haplotype in VDR had a 3-fold higher risk of stress fracture than subjects carrying both (OR = 3.22, 95% CI 1.38-7.49, p = 0.007. In addition, the LRP5 haplotype A-G-G-C alone and in combination with the VDR haplotype C-A was associated with stress fractures through reduced body weight and BMI. Conclusions Our findings suggest that genetic factors play a role in the development of stress fractures in individuals subjected to heavy exercise and mechanical loading. The present results can be applied to the design of future studies that will further elucidate the genetics of stress fractures.

  5. The three-year incidence of fracture in chronic kidney disease.

    Naylor, Kyla L; McArthur, Eric; Leslie, William D; Fraser, Lisa-Ann; Jamal, Sophie A; Cadarette, Suzanne M; Pouget, Jennie G; Lok, Charmaine E; Hodsman, Anthony B; Adachi, Jonathan D; Garg, Amit X


    Knowing a person's fracture risk according to their kidney function, gender, and age may influence clinical management and decision-making. Using healthcare databases from Ontario, Canada, we conducted a cohort study of 679,114 adults of 40 years and over (mean age 62 years) stratified at cohort entry by estimated glomerular filtration rate ((eGFR) 60 and over, 45-59, 30-44, 15-29, and under 15 ml/min per 1.73 m(2)), gender, and age (40-65 and over 65 years). The primary outcome was the 3-year cumulative incidence of fracture (proportion of adults who fractured (hip, forearm, pelvis, or proximal humerus) at least once within 3-years of follow-up). Additional analyses examined the fracture incidence per 1000 person-years, hip fracture alone, stratification by prior fracture, stratification by eGFR and proteinuria, and 3-year cumulative incidence of falls with hospitalization. The 3-year cumulative incidence of fracture significantly increased in a graded manner in adults with a lower eGFR for both genders and both age groups. The 3-year cumulative incidence of fracture in women over 65 years of age across the 5 eGFR groups were 4.3%, 5.8%, 6.5%, 7.8%, and 9.6%, respectively. Corresponding estimates for men over 65 years were 1.6%, 2.0%, 2.7%, 3.8%, and 5.0%, respectively. Similar graded relationships were found for falls with hospitalization and additional analyses. Thus, many adults with chronic kidney disease will fall and fracture. Results can be used for prognostication and guidance of sample size requirements for fracture prevention trials.

  6. Incidence and direct hospitalisation costs of hip fractures in Vilnius, capital of Lithuania, in 2010

    Tamulaitiene Marija


    Full Text Available Abstract Background Few epidemiological data on hip fractures were previously available in Lithuania. The aim of this study was to estimate the incidence and hospital costs of hip fractures in Vilnius in 2010. Methods Data were collected from the medical charts of all patients admitted to hospitals in Vilnius (population, 548,835 due to new low-energy trauma hip fracture, during 2010. The estimated costs included ambulance transportation and continuous hospitalisation immediately after a fracture, which are covered by the Lithuanian healthcare system. Results The incidence of new low-energy trauma hip fractures was 252 (308 women and 160 men per 100,000 inhabitants of Vilnius aged 50-years or more. There was an exponential increase in the incidence with increasing age. The overall estimated cost of hip fractures in Vilnius was 1,114,292 EUR for the year 2010. The greatest part of the expenditure was accounted for by fractures in individuals aged 65-years and over. The mean cost per case was 2,526.74 EUR, and cost varied depending on the treatment type. Hip replacement did not affect the overall mean costs of hip fracture. The majority of costs were incurred for acute (53% and long-term care (35% hospital stays, while medical rehabilitation accounted for only 12% of the overall cost. The costs of hip fracture were somewhat lower than those found in other European countries. Conclusion The data on incidence and costs of hip fractures will help to assess the importance of interventions to reduce the number of fractures and associated costs.

  7. Measurement of residual stresses using fracture mechanics weight functions

    Fan, Y. [Bettis Atomic Power Laboratory, West Mifflin, PA (United States)


    A residual stress measurement method has been developed to quantify through-the-thickness residual stresses. Accurate measurement of residual stresses is crucial for many engineering structures. Fabrication processes such as welding and machining generate residual stresses that are difficult to predict. Residual stresses affect the integrity of structures through promoting failures due to brittle fracture, fatigue, stress corrosion cracking, and wear. In this work, the weight function theory of fracture mechanics is used to measure residual stresses. The weight function theory is an important development in computational fracture mechanics. Stress intensity factors for arbitrary stress distribution on the crack faces can be accurately and efficiently computed for predicting crack growth. This paper demonstrates that the weight functions are equally useful in measuring residual stresses. In this method, an artificial crack is created by a thin cut in a structure containing residual stresses. The cut relieves the residual stresses normal to the crack-face and allows the relieved residual stresses to deform the structure. Strain gages placed adjacent to the cut measure the relieved strains corresponding to incrementally increasing depths of the cut. The weight functions of the cracked body relate the measured strains to the residual stresses normal to the cut within the structure. The procedure details, such as numerical integration of the singular functions in applying the weight function method, will be discussed. (author)

  8. Endogenous estradiol and the risk of incident fracture in postmenopausal women: the OPUS study.

    Finigan, J; Gossiel, F; Glüer, C C; Felsenberg, D; Reid, D M; Roux, C; Eastell, R


    Some, but not all, studies have found that low endogenous estradiol levels in postmenopausal women are predictive of fractures. The aim of this study was to examine the roles of endogenous estradiol (E(2)), sex hormone binding globulin (SHBG), and dehydroepiandrosterone sulfate (DHEAS) in the prediction of incident vertebral and nonvertebral fractures. The study subjects were 797 postmenopausal women from the population-based OPUS (Osteoporosis and Ultrasound Study) study. Spine radiographs and dual-energy X-ray absorptiometry scans were obtained for all subjects at baseline and 6-year follow-up. Nonfasting blood samples were taken at baseline for E(2), SHBG, DHEAS, and bone turnover markers. Incident nonvertebral fractures were self-reported and verified; vertebral fractures were diagnosed at a single center from spinal radiographs. Medical and lifestyle data were obtained by questionnaire at each visit. Thirty-nine subjects had an incident vertebral fracture and 119 a nonvertebral fracture. Estradiol in the lowest quartile predicted vertebral fracture independent of confounders including age, body mass index, bone mineral density, bone turnover, fracture history, and use of antiresorptive therapy, with an OR of 2.97 (95 % confidence interval [CI] 1.52-5.82) by logistic regression. A calculated free estradiol index was not a stronger predictor than total E(2). Higher SHBG predicted vertebral fracture independently of age and body mass index, but not independently of E(2), bone mineral density, or prevalent fracture. Low DHEAS did not predict vertebral fracture. Nonvertebral fractures were not predicted by any of E(2), SHBG, or DHEAS, either in univariate or multivariate analyses. These findings suggest that there may be mechanistic differences in the protective effect of E(2) at vertebral compared with nonvertebral sites.

  9. Bilateral First Rib Stress Fractures in a Basketball Player

    Abidin (Radyoloji Kilincer


    Full Text Available I read the article published by Aydogdu et al with a great interest. I congratulate them for this successfully written case report. Additionally, I want to focus an important point about the case they presented is that the diagnosis in that case is likely stress fracture. It is understood from the text and title that they avoided to make a diagnosis of stress fracture in the case, despite of history of lifting heavy weights for three days. And also I decided to mention through this article to an example of our case with bilateral first rib old fractures.

  10. Emergence of anomalous transport in stressed rough fractures

    Kang, Peter K.; Brown, Stephen; Juanes, Ruben


    We report the emergence of anomalous (non-Fickian) transport through a rough-walled fracture as a result of increasing normal stress on the fracture. We show that the origin of this anomalous transport behavior can be traced to the emergence of a heterogeneous flow field dominated by preferential channels and stagnation zones, as a result of the larger number of contacts in a highly stressed fracture. We show that the velocity distribution determines the late-time scaling of particle spreading, and velocity correlation determines the magnitude of spreading and the transition time from the initial ballistic regime to the asymptotic anomalous behavior. We also propose a spatial Markov model that reproduces the transport behavior at the scale of the entire fracture with only three physical parameters. Our results point to a heretofore unrecognized link between geomechanics and particle transport in fractured media.

  11. Osteoporosis in Japan: factors contributing to the low incidence of hip fracture.

    Fujita, T


    Hip fracture incidence seems to be lower in Japan than in many Western countries, but the difference is apparently becoming smaller with progressive Westernization of the Japanese lifestyle and nutritional habits. Nutrition cannot explain the lower incidence of hip fracture. A lower calcium intake prevails in Japan. Genetic differences in body build, including a lower center of gravity, better motor function and agility, well developed hip musculature and small but more fracture-resistant bones secondary to a difference in life- and work-style may contribute to fewer falls and a lower fracture rate among Japanese than among their Western counterparts. Such traditional lifestyle habits as sitting directly on the floor are rapidly decreasing, and time will tell how much of the low incidence of hip fracture in Japan can be explained by lifestyle and how much by genetic and other factors. The Japanese women who now enjoy a low hip fracture incidence led a hard physical life when they were young. This may be a lesson to the young of future generations in how to avoid bone fractures when they are old. Bone health may be achieved by enjoying life through sports or even the tea ceremony in place of the hard physical work of their ancestors, which is gradually disappearing.

  12. Early identification and management of critical incident stress.

    Caine, Randy M; Ter-Bagdasarian, Levon


    Everyone experiences stress. That stress may be related to work (internal), community (external), or family; it may be cumulative or related to a particular critical incident. The cost related to treating acute stress is staggering, both to individuals and to organizations. Critical care nurses are well educated in the physiological responses to the stress of acute illness. Recognizing the emotional impact of stress and the techniques to manage it in themselves and in those with whom they work is equally as important. CISD is widely advocated as an intervention after critical incidents. Although debriefing in and of itself is effective, a single-session semistructured crisis intervention will not prevent posttraumatic stress; thus, the use of CISD as part of a comprehensive multifaceted approach to the management of acute stress related to a critical incident is recommended.

  13. A case report of missed femoral neck stress fracture

    Onibere Oruaro Adebayo


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

  14. Effect of lower third molars on the incidence of mandibular angle and condylar fractures.

    Choi, Byung-Joon; Park, Soong; Lee, Deok-Won; Ohe, Joo-Young; Kwon, Yong-Dae


    Numerous previous studies already have proven that mandibles with a third molar are significantly more susceptible to angle fracture by external force. Similarly, other data suggest that the absence of a third molar increases the risk of condylar fracture, while concurrently decreasing the risk of angular fracture. We attempt to characterize the effect of a third molar on the incidence of mandibular angle and condylar fractures. This retrospective study reviews data from 385 patients, all of whom were seen in our clinics between February 2006 and November 2009. All data were collected from clinical examination notes and panoramic radiographs, with third-molar state evaluated by the Pell and Gregory classification system. Our results mirror those of previous studies. The incidence of mandibular angle fracture was significantly greater on sides with a third molar, whereas the condylar fracture rate significantly increased in mandibles lacking a third molar or without a fully erupted third molar. The rate of symphysis and mandibular angle fracture was also high in cases of multiple comorbid fractures. Both the presence and the state of the lower third molar affect the risk of future mandibular angle and condylar fracture.

  15. [Bilateral stress fracture of the mid-tibial shaft in a professional dancer].

    Tomčovčík, L; Tomčovčíková, A


    Stress fractures of the anterior cortex of the mid-tibial shaft in dancers are rare, with a 1.4 % incidence in injured eli- te dancers. Treatment can be difficult and long-lasting and can seriously influence the dancer's career. The authors pre- sent the case of a 26-year-old professional dancer of a folk dance ensemble who suffered rare simultaneous bilateral mid-tibial shaft stress fractures. A conservative method of treatment with avoiding exercise and dancing activities resulted in the resolution of symptoms and healing of the fractures after 6 months. The patient finished his dancing career because of the necessity of a prolonged therapy interfering with his dancing activities. Current options of the treatment are also presented.

  16. Stress generation and hierarchical fracturing in reactive systems

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


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

  17. Secular trend in the incidence of hip fracture in Catalonia, Spain, 2003-2014.

    Pueyo-Sánchez, Maria-Jesús; Larrosa, Marta; Suris, Xavier; Casado, Enrique; Auleda, Jaume; Fusté, Josep; Ortún, Vicente


    to describe the secular trend and seasonal variation in the incidence of hip fracture (HF) over 12 years (2003-2014) in Catalonia, the community with the highest incidence of HF in Spain. data about age, gender, type of fracture and month of hospitalisation among patients aged 65 years and older discharged with a diagnosis of HF were collected. Crude and age-standardised annual incidence rate were reckoned. To analyse HF trend, the age/sex-adjusted average annual change in incidence (incidence rate ratio, IRR) was calculated. we identified 100,110 HF in the period, with an increase of 16.9% (women 13.4%; men 28.4%). Trochanteric fractures were the most frequent (55.8%). The crude incidence rate (per 100,000 population) decreased from 677.2 (95% confidence interval (95% CI) 662.0-692.7) to 657.6 (95% CI 644.0-671.5). The standardised incidence rate decreased from 754.0 (95% CI 738.6-769.3) to 641.5 (95% CI 627.7-655.3), with a sharp decrease in women (-16.8%) while it was stable in men. The incidence by type of fracture was stable. The trend throughout the period showed a slight decrease with IRR 0.99 (95% CI 0.98-0.99; P = 0.025). The incidence was stable in the oldest group (+85 years), while there was a downward trend in the younger groups. A significant seasonal pattern was observed, with more cases in winter and less in summer (spring as reference). the secular trend reveals a decreasing incidence of HF although the absolute number has increased in the last 12 years in Catalonia. Trochanteric fractures were the most prevalent and a seasonal pattern was observed, with more cases in winter.

  18. Incidence and socioeconomic burden of hip fractures in Italy: extension study 2003-2005

    G. Guglielmi


    Full Text Available Objectives: we aimed to analyze incidence and costs of hip fractures in Italy. Methods: we analyzed the Italian Ministry of Health national hospitalization and DRGs databases concerning fractures occurred in people ≥65 between 2003 and 2005. We have estimated incidence and direct costs sustained by the National Health Service for hospitalization and treatment of hip fractures on the basis of the value of the Diagnosis Related Groups (DRGs referring to hip fractures. The expenses of rehabilitation and indirect costs were based on regional estimations. Results: between 2003 and 2005 we registered almost 90,000 hospital admissions per year (corresponding to 75,000 patients because of hip fractures in people aged ≥65. Women accounted for the majority of hospital admissions due to hip fractures (78.0%; n=214,519. Among women, 84.3% of fractures (n=180,861 occurred in patients ≥75, which is known to be the age group with the highest prevalence of osteoporosis. Hospitalizations of both men and women showed an increasing trend across all the examined period. Hospital costs increased up to 467 million euros in 2005, while rehabilitation costs rose up to 531 million in the same year. Conclusions: hip fractures in the Italian population are increasing and represent a major public health challenge.

  19. Adherence to a Mediterranean-style diet and incident fractures: pooled analysis of observational evidence.

    Kunutsor, Setor K; Laukkanen, Jari A; Whitehouse, Michael R; Blom, Ashley W


    The Mediterranean diet is associated with decreased morbidity and mortality from various chronic diseases. Adherence to a Mediterranean-style diet has been suggested to have protective effects on bone health and decreases the incidence of bone fractures, but the evidence is not clear. We conducted a systematic review and meta-analysis of available observational studies to quantify the association between adherence to a Mediterranean-style diet, as assessed by the Mediterranean Diet Score (MDS), and the risk of fractures in the general population. Relevant studies were identified in a literature search of MEDLINE, EMBASE, Web of Science, and reference lists of relevant studies to October 2016. Relative risks (RRS) with 95% confidence intervals (CIs) were aggregated using random-effects models. Five observational studies with data on 353,076 non-overlapping participants and 33,576 total fractures (including 6,881 hip fractures) were included. The pooled fully adjusted RR (95% CI) for hip fractures per 2-point increment in adherence to the MDS was 0.82 (0.71-0.96). Adherence to the MDS was not associated with the risk of any or total fractures based on pooled analysis of only two studies. Limited observational evidence supports a beneficial effect of adherence to a Mediterranean-style diet on the incidence of hip fractures. Well-designed intervention studies are needed to elucidate the relationship between adherence to a Mediterranean-style diet and the risk of adverse bone health outcomes such as fractures.

  20. Dietary and training predictors of stress fractures in female runners.

    Wentz, Laurel; Liu, Pei-Yang; Ilich, Jasminka Z; Haymes, Emily M


    To compare female runners with and without a history of stress fractures to determine possible predictors of such fractures. 27 female runners (age 18-40 yr) who had had at least 1 stress fracture were matched to a control sample of 32 female runners without a history of stress fractures. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (iDXA). Subjects answered questionnaires on stress-fracture history, training, menstrual status, and diet. No significant differences were found in menstrual characteristics, diet and dairy intake, or bone measurements. Weekly servings of milk during middle school significantly predicted BMD at the femur (p = .010), femoral neck (p = .002), Ward's triangle (p = .014), and femoral shaft (p = .005). Number of menstrual cycles in the previous year predicted femoral-neck BMD (p = .004). Caffeine intake was negatively associated with BMD of the femur (p = .010), femoral neck (p = .003), trochanter (p = .038), and femoral shaft (p = .035). Weekly hours of training were negatively associated with total-body BMD (p = .021), total-body bone mineral content (p = .028), and lumbar-spine BMD (p = .011). Predictors for stress fractures included the number of years running, predominantly running on hard ground, irregular menstrual history, low total-body BMD, and low current dietary calcium intake when controlling for body-mass index (Nagelkerke R2 = .364). Servings of milk during middle-school years were positively correlated with hip BMD, although current calcium intake, low BMD, irregular menstrual history, hard training surface, and long history of training duration were the most important predictors of stress fractures.

  1. Postpartum osteoporosis associated with proximal tibial stress fracture

    Clemetson, I.A.; Anderson, S.E. [Department of Radiology, University Hospital of Bern, Inselspital, 3010, Bern (Switzerland); Popp, A.; Lippuner, K. [Department of Osteology, University Hospital of Bern, Inselspital, 3010, Bern (Switzerland); Ballmer, F. [Knee and Sports Medicine Unit, Lindenhofspital Bern, 3012, Bern (Switzerland)


    A 33-year-old woman presented with acute nonspecific knee pain, 6 months postpartum. MR imaging, computed tomography and radiography were performed and a proximal tibia plateau insufficiency fracture was detected. Bone densitometry demonstrated mild postpartum osteoporosis. To our knowledge these findings have not been described in this location and in this clinical setting. The etiology of the atraumatic fracture of the tibia is presumed to be due to a low bone mineral density. The bone loss was probably due to pregnancy, lactation and postpartum hormonal changes. There were no other inciting causes and the patient was normocalcemic. We discuss the presence of a postpartum stress fracture in a hitherto undescribed site in a patient who had lactated following an uncomplicated pregnancy and had no other identifiable cause for a stress fracture. (orig.)

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

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


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

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

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


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

  4. Stress Fracture of the Proximal Fibula in Military Recruits

    Hong, Seoung Hwan; Chu, In Tak


    Background We wanted to report on stress fracture of the proximal fibula and to suggest the pathomechanism of this fracture. Methods Between April 2004 through April 2005, the military recruits who complained of leg pain during the 6 weeks basic training in the Republic of Korea Marine Corps education and training group were evaluated according to their clinical manifestations and plain radiographs. Results Twelve recruits of 635 recruits who complained leg pain were diagnosed as having fibul...

  5. Numerical Investigation on Stress Shadowing in Fluid Injection-Induced Fracture Propagation in Naturally Fractured Geothermal Reservoirs

    Yoon, Jeoung Seok; Zimmermann, Günter; Zang, Arno


    In low permeability shale reservoirs, multi-stage hydraulic fracturing is largely used to increase the productivity by enlarging the stimulated rock volume. Hydraulic fracture created alters the stress field around it, and affects the subsequent fractures by the change of the stress field, in particular, mostly increased minimum principal stress at the area of subsequent fracturing. This is called stress shadow which accumulates as the fracturing stages advance from toe to heel. Hydraulic fractures generated in such altered stress field are shorter and compact with orientation deviating significantly from the far-field maximum horizontal stress orientation. This paper presents 2D discrete element-based numerical modeling of multi-stage hydraulic fracturing in a naturally fractured reservoir and investigates stress shadowing. The stress shadowing is tested with two different injection scenarios: constant and cyclic rate injections. The results show that cyclic injection tends to lower the effect of stress shadow as well as mitigates the magnitude of the induced seismicity. Another modeling case is presented to show how the stress shadow can be utilized to optimize a hydraulic fracture network in application to Groß Schönebeck geothermal reservoir, rather than being mitigated. The modeling demonstrated that the stress shadow is successfully utilized for optimizing the geothermal heat exchanger by altering the initial in situ stress field from highly anisotropic to less or even to isotropic.

  6. Longitudinal change in hip fracture incidence after starting risedronate or raloxifene: an observational study.

    Ferrari, Serge; Nakamura, Toshitaka; Hagino, Hiroshi; Fujiwara, Saeko; Lange, Jeffrey L; Watts, Nelson B


    This study examined patients' risk profiles and adherence to treatment in relation to the effect of risedronate and raloxifene on hip fracture incidence. Administrative billing data were used to follow two cohorts of women aged 65 and older after starting therapy with either risedronate (n = 86,735) or raloxifene (n = 37,726). The fracture risk profile was described using a 6-month history period before starting therapy. Effectiveness of each therapy was evaluated by comparing the incidence of hip fractures during the first 3 months with the subsequent 12 months among women adherent (medication possession ratio >80%) compared with those non-adherent to treatment. At the start of therapy, the raloxifene cohort was younger than the risedronate cohort (median age 73 vs. 76 years) and had fewer prior fractures (p < 0.01 for both). In the first 3 months of therapy, hip fracture incidence was lower in the raloxifene group (0.51 per 100 person-years) compared with the risedronate group (0.94 per 100 person-years). In the subsequent 12 months, the incidence of hip fractures decreased among patients adherent to the risedronate regimen [relative risk (RR) 0.70, 95% CI 0.59-0.84, p < 0.01] and did not change significantly among patients adherent to the raloxifene regimen (RR 1.02, 95% CI 0.73-1.44). In poorly adherent patients, neither drug decreased hip fracture risk. Risedronate treatment in adherent patients rapidly decreased the risk of hip fractures, whereas raloxifene treatment did not.

  7. Frequent manual repositioning and incidence of pressure ulcers among bedbound elderly hip fracture patients

    Rich, Shayna E.; Margolis, David; Shardell, Michelle; Hawkes, William G; Miller, Ram R.; Amr, Sania; Baumgarten, Mona


    Frequent manual repositioning is an established part of pressure ulcer (PU) prevention, but there is little evidence for its effectiveness. This study examined the association between repositioning and PU incidence among bedbound elderly hip fracture patients, using data from a 2004–2007 cohort study in nine Maryland and Pennsylvania hospitals. Eligible patients (n=269) were age≥65 years, underwent hip fracture surgery, and were bedbound at index study visits (during the first five days of ho...

  8. Age-specific incidence of hip fracture in the elderly: a healthy decline.

    Green, C


    Hip fractures in the elderly are an important source of morbidity and mortality. The predicted increase in the number of hip fractures due to the increasing elderly population has not been universally observed. The purpose of this study was to examine the incidence of hip fractures over a twenty year period to determine if this rise is occurring in our region. All hip fractures from the unit over 20 years were identified. Population data for those over 65 in the catchment area of our hospital was acquired. The rate of fractures occurring each year relative to the population was determined. The results were split into age groups. There was a strong correlation between the population rise and number of fractures (p = 0.77). But there was no significant difference in the rate of fracture over time (p = 0.41). However, the average age at which fracture occurred increased by two years. In addition we show the overall trend in the rate of fractures decreases in the younger age groups and increases in the older age groups. Therefore, the predicted rapid increase in rate is not occurring. This probably reflects the strengthening of the economy in Ireland from the 1930\\'s onwards, leading to a healthier population.


    Andréia Costa Ferreira


    Full Text Available Introduction:The elderly population is growing gradually in recent years, it increases theincidence of elderly people at risk of falls and hip fractures develop.Objective:To identifythe incidence and characterize elderly patients hospitalized with hip fractures in theOrthopedic Clinic of the Hospital Regional Dr º Antonio Cáceres sources.Methodology:Thisis an epidemiological, descriptive, quantitative and retrospective data collection documentbasis. The study population comprised 105.Results:It was found that the fracture of thefemur showed predominance in females, comprising 40.90% of the cases and the right lowerlimb most affected. As for location, the trochanteric fractures showed 39.04%, followed byfractures of the femoral shaftwith 27.61% of the cases. The treatment applied in 62.85% ofpatients went to surgery.Conclusion:It is concluded that the femur fracture may preclude theelderly in their daily activities.

  10. C2 Fracture Subtypes, Incidence, and Treatment Allocation Change with Age: A Retrospective Cohort Study of 233 Consecutive Cases.

    Robinson, Anna-Lena; Möller, Anders; Robinson, Yohan; Olerud, Claes


    The currently available data on the distribution of C2 fracture subtypes is sparse. This study was designed to identify the proportions of the second cervical vertebra (C2) fracture subtypes and to present age and gender specific incidences of subgroups. A dataset of all patients treated between 2002 and 2014 for C2 fractures was extracted from the regional hospital information system. C2 fractures were classified into odontoid fractures types 1, 2, and 3, Hangman's fractures types 1, 2, and 3, and atypical C2 fractures. 233 patients (female 51%, age 72 ± 19 years) were treated for a C2 fracture. Odontoid fractures were found in 183 patients, of which 2 were type 1, 127 type 2, and 54 type 3, while 26 of C2 fractures were Hangman's fractures and 24 were atypical C2 fractures. In the geriatric subgroup 89% of all C2 fractures were odontoid, of which 71% were type 2 and 29% type 3. There was an increasing incidence of odontoid fractures types 2 and 3 from 2002 to 2014. 40% of C2 fractures were treated surgically. This study presents reliable subset proportions of C2 fractures in a prospectively collected regional cohort. Knowledge of these proportions facilitates future epidemiological studies of C2 fractures.

  11. C2 Fracture Subtypes, Incidence, and Treatment Allocation Change with Age: A Retrospective Cohort Study of 233 Consecutive Cases

    Anna-Lena Robinson


    Full Text Available The currently available data on the distribution of C2 fracture subtypes is sparse. This study was designed to identify the proportions of the second cervical vertebra (C2 fracture subtypes and to present age and gender specific incidences of subgroups. A dataset of all patients treated between 2002 and 2014 for C2 fractures was extracted from the regional hospital information system. C2 fractures were classified into odontoid fractures types 1, 2, and 3, Hangman’s fractures types 1, 2, and 3, and atypical C2 fractures. 233 patients (female 51%, age 72±19 years were treated for a C2 fracture. Odontoid fractures were found in 183 patients, of which 2 were type 1, 127 type 2, and 54 type 3, while 26 of C2 fractures were Hangman’s fractures and 24 were atypical C2 fractures. In the geriatric subgroup 89% of all C2 fractures were odontoid, of which 71% were type 2 and 29% type 3. There was an increasing incidence of odontoid fractures types 2 and 3 from 2002 to 2014. 40% of C2 fractures were treated surgically. This study presents reliable subset proportions of C2 fractures in a prospectively collected regional cohort. Knowledge of these proportions facilitates future epidemiological studies of C2 fractures.

  12. Stress fracture in acetabular roof due to motocross: case report

    Alexandre de Paiva Luciano


    Full Text Available ABSTRACT One of the first steps to be taken in order to reduce sports injuries such as stress fractures is to have in-depth knowledge of the nature and extent of these pathological conditions. We present a case report of a stress fracture of the acetabular roof caused through motocross. This type of case is considered rare in the literature. The description of the clinical case is as follows. The patient was a 27-year-old male who started to have medical follow-up because of uncharacteristic pain in his left hip, which was concentrated mainly in the inguinal region of the left hip during motocross practice. After clinical investigation and complementary tests, he was diagnosed with a stress fracture of the acetabular roof.

  13. Stress fracture in acetabular roof due to motocross: case report.

    de Paiva Luciano, Alexandre; Filho, Nelson Franco


    One of the first steps to be taken in order to reduce sports injuries such as stress fractures is to have in-depth knowledge of the nature and extent of these pathological conditions. We present a case report of a stress fracture of the acetabular roof caused through motocross. This type of case is considered rare in the literature. The description of the clinical case is as follows. The patient was a 27-year-old male who started to have medical follow-up because of uncharacteristic pain in his left hip, which was concentrated mainly in the inguinal region of the left hip during motocross practice. After clinical investigation and complementary tests, he was diagnosed with a stress fracture of the acetabular roof.

  14. Critical incident stress debriefing: a family nursing intervention.

    Ragaisis, K M


    Critical Incident Stress Debriefing is an intervention that assists patients and families to master the stresses resulting from being a witness to or victim of violent acts. Intervening at the level of the family system, the clinical nurse specialist can facilitate communication, decrease anxiety, and provide education regarding the post-trauma response.

  15. Stressful life events and incident metabolic syndrome : The Hoorn study

    Rutters, F.; Pilz, S.; Koopman, A.D.; Rauh, S.P.; Pouwer, F.; Stehouwer, C.D.; Elders, P.J.; Nijpels, G.; Dekker, J.M.


    Stressful life events are associated with the metabolic syndrome in cross-sectional studies, but prospective studies addressing this issue are rare and limited. We therefore evaluated whether the number of stressful life events is associated with incident metabolic syndrome. We assessed the

  16. Stressful life events and incident metabolic syndrome : the Hoorn study

    Rutters, Femke; Pilz, Stefan; Koopman, Anitra D M; Rauh, Simone P; Pouwer, Frans; Stehouwer, Coen D A; Elders, Petra J; Nijpels, Giel; Dekker, Jacqueline M


    Stressful life events are associated with the metabolic syndrome in cross-sectional studies, but prospective studies addressing this issue are rare and limited. We therefore evaluated whether the number of stressful life events is associated with incident metabolic syndrome. We assessed the associat

  17. Fractures of the Sacrum After Chemoradiation for Rectal Carcinoma: Incidence, Risk Factors, and Radiographic Evaluation

    Kim, Han Jo [Department of Orthopedic Surgery, Washington University, St. Louis, Missouri (United States); Boland, Patrick J. [Department of Surgery, Orthopaedic Service, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Meredith, Dennis S. [Hospital for Special Surgery, Department of Orthopaedic Surgery, New York, New York (United States); Lis, Eric [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Zhang Zhigang; Shi Weiji [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Yamada, Yoshiya J. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Goodman, Karyn A., E-mail: [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)


    Purpose: Sacral insufficiency fractures after adjuvant radiation for rectal carcinoma can present similarly to recurrent disease. As a complication associated with pelvic radiation, it is important to be aware of the incidence and risk factors associated with sacral fractures in the clinical assessment of these patients. Methods and Materials: Between 1998 and 2007, a total of 582 patients with locally advanced rectal carcinoma received adjuvant chemoradiation and surgical excision. Of these, 492 patients had imaging studies available for review. Hospital records and imaging studies from all 492 patients were retrospectively evaluated to identify risk factors associated with developing a sacral insufficiency fracture. Results: With a median follow-up time of 3.5 years, the incidence of sacral fractures was 7.1% (35/492). The 4-year sacral fracture free rate was 0.91. Univariate analysis showed that increasing age ({>=}60 vs. <60 years), female sex, and history of osteoporosis were significantly associated with shorter time to sacral fracture (P=.01, P=.004, P=.001, respectively). There was no significant difference in the time to sacral fracture for patients based on stage, radiotherapy dose, or chemotherapy regimen. Multivariate analysis showed increasing age ({>=}60 vs. <60 years, hazard ratio [HR] = 2.50, 95% confidence interval [CI] = 1.22-5.13, P=.01), female sex (HR = 2.64, CI = 1.29-5.38, P=.008), and history of osteoporosis (HR = 3.23, CI = 1.23-8.50, P=.02) were independent risk factors associated with sacral fracture. Conclusions: Sacral insufficiency fractures after pelvic radiation for rectal carcinoma occur more commonly than previously described. Independent risk factors associated with fracture were osteoporosis, female sex, and age greater than 60 years.

  18. Bilateral stress fractures of the ulnae in a Kendo (Japanese fencing) player.

    Sujino, T; Ohe, T; Shinozuka, M


    A case of bilateral stress fractures of the ulnae in a Kendo (Japanese fencing) player is reported; the mechanism of the fractures, particularly the difference in the site of fracture between the right and left ulna, is discussed.

  19. Critical incident stress debriefing in international aid workers.

    Townsend, C J; Loughlin, J M


    Missionaries are well known to suffer the effects of stress. Patricia Miersma relates missionary stress to combat related stress. 1 Development workers too are known to be at increased risk of death whilst overseas-mostly due to traumatic incidents. Relief workers voluntarily enter high stress situations. These overseas workers are at real risk of Post Traumatic Stress Disorder (PTSD). The issue of Critical Incident Stress Debriefing (CISD, or Psychological Debriefing) has been critically examined in an editorial in the British Medical Journal.3 The first randomized, controlled study of CISD that we are aware of (for motor vehicle accident survivors) was published in 1996.4 With 54 intervention subjects, it did not demonstrate effectiveness.

  20. High fall incidence and fracture rate in elderly dialysis patients

    Polinder-Bos, H. A.; Emmelot-Vonk, M. H.; Gansevoort, R. T.; Diepenbroek, A.; Gaillard, C. A. J. M.


    Background: Although it is recognised that the dialysis population is ageing rapidly, geriatric complications such as falls are poorly appreciated, despite the many risk factors for falls in this population. The objective of this study was to determine the incidence, complications and risk factors f

  1. Stress Related Fracturing in Dimension Stone Quarries

    Hamdi Deliormanli, Ahmet; Maerz, Norbert H.


    In Missouri, the horizontal stresses (pressures) in the near surface rock are uncommonly high. While the vertical stresses in rock are simply a function of the weight of the overlying rock, near surface stresses can be many times higher. The near surface horizontal stresses can be in excess of 5 times greater than the vertical stresses. In this research, Flatjack method was used to measure horizontal stress in Red Granite Quarry in Missouri. The flat jack method is an approved method of measuring ground stresses. A saw cut is used to “relax” the stress in the ground by allowing the rock to deform inwards the cut. A hydraulic flat jack is used to inflate the slot; to push the rock back to its stressed position, as measured by a strain gauge on either side of the slot. The pressure in the jack, when the rock is exactly back to its original position, is equal to the ground stress before the saw cut was made. According to the results, present production direction for each pit is not good because the maximum stress direction is perpendicular with production direction. This case causes unintentional breakage results in the loss rock. The results show that production direction should be changed.

  2. The Association of Femoral Neck Stress Fractures with Femoral Acetabular Impingement

    Safran, Marc R.; Goldin, Michael; Anderson, Christian; Fredericson, Michael; Stevens, Kathryn J.


    Objectives: To determine if there is an increased incidence of femoral acetabular impingement (FAI) in patients presenting with stress fractures of the femoral neck. Methods: After IRB approval, the imaging studies of 25 athletes (22 females, 3 males, mean age 26, range 19 - 39 years) with femoral neck stress injuries were assessed for the presence of features suggesting FAI, including acetabular retroversion, coxa profunda, abnormal femoral head-neck junction, fibrocystic change, os acetabulae, labral tear and chondral injury. All subjects had to have an adequate AP Pelvis radiograph, a lateral radiograph of the affected hip, and an MRI of the affected hip. The alpha angle, anterior offset ratio, and center to edge (CE) angle were measured on radiographs. The grade of stress injury was determined on MR images. All images and measurements were made by a musculoskeletal fellowship trained radiologist, a fellowship trained orthopaedic surgeon, an orthopaedic sports medicine fellow and a physical medicine and rehabilitation resident. Charts were reviewed to determine treatment of the stress fracture, outcome and final follow up, as well as to determine if the patient had any further treatment for their hip. Results: Of the 25 hips (18 right, 7 left) with femoral neck stress reactions, 9 were grade 2 (bone marrow edema), 5 were grade 3 (high T2 and low T1 marrow signal), and 11 were grade 4 (stress fracture). Twenty patients (80%) had coxa profunda - where the floor of the cotyloid fossa touches or extends beyond the ilioischial line (incidence in general population is 15.2% of males, and 19.4% of females). Coxa profunda, defined by the floor of the cotyloid fossa touching or extending beyond the ilioischial line and a center edge angle of more than 35o, was present in 28% of subjects. Acetabular retroversion as assessed by the crossover sign was present in 42% (normal incidence is 5% of population). Center edge angle was greater than 35o in 20% and greater than 40 o

  3. Incidence investigation and analysis of hepatic stress injury after trauma

    WANG Quanchu; ZHANG Yafei; CHENG Zhengxiang


    Objective To investigate the etiology and pathogenesis of hepatic stress injury after trauma.Methods 4677 patients with severe trauma in 153th Hospital of PLA from Jan.2004 to Jul.2005 were enrolled in this study to investigate the incidence of hepatic stress injury,and furthermore,in combination with medical information,the possible pathogenesis was analyzed.Results The main manifestation of hepatic stress injury was the elevated ALT or AST levels (387 cases,8.3% ).The incidence of hepatic stress injury after hand injury,burn injury,head injury,bone injury,abdominal injury,and thoracic injury were 16.6%,6.9%,5.6%,5.0%,3.8% and 2.0%,respectively,and among which,the incidence of hepatic stress injury after hand injury was statistically highest (P <0.01 ).Conclusion The total incidence of hepatic stress injury after trauma was 8.3%.Intestinal endotoxemia might be one of the beginning components of hepatic stress injury after trauma.

  4. Incidence of hip fracture in Barranquilla, Colombia, and the development of a Colombian FRAX model.

    Jaller-Raad, J J; Jaller-Char, J J; Lechuga-Ortiz, J A; Navarro-Lechuga, E; Johansson, H; Kanis, J A


    A FRAX model for Colombia was released June 30, 2010. This article describes the data used to develop the Colombian FRAX model and illustrates its features compared to other countries. Hip fracture cases aged 50 years or more who were referred to all hospitals serving the city of Barranquilla were identified prospectively over a 3-year period (2004-2006). Age- and sex-stratified hip fracture incidence rates were computed using the 2005 census. Present and future numbers of hip fracture cases in Colombia were calculated from the age- and sex-specific incidence and the national population demography. Mortality rates for 1999 were extracted from nationwide databases and used to estimate hip fracture probabilities. For other major fractures (clinical vertebral, forearm, and humerus), incidence rates were imputed, using Swedish ratios for hip to other major osteoporotic fracture, and used to construct the FRAX model. Incidence of hip fracture increased with age, more markedly in women than in men. Over all ages, the female to male ratio was 1.7. By extrapolation, there were estimated to be 7,902 new hip fracture cases (2,673 men, 5,229 women) in Colombia in 2010, which was predicted to increase to 22,720 cases (7,568 men, 15,152 women) in 2035. The 10-year probability of hip or major fracture was increased in patients with a clinical risk factor, lower BMI, female gender, a higher age, and a decreased BMD T score. The remaining lifetime probability of hip fracture at the age of 50 years was 2.5 and 4.7 % in men and women, respectively, which were lower than rates in a Mexican population (3.8 and 8.5 %, respectively) and comparable with estimates for Venezuela (2.4 and 7.5 %, respectively). The FRAX tool is the first country-specific fracture-prediction model available in Colombia. It is based on the original FRAX methodology, which has been externally validated in several independent cohorts. Despite some limitations, the strengths make the Colombian FRAX tool a good

  5. Dietary intake and stress fractures among elite male combat recruits

    Moran Daniel S


    Full Text Available Abstract Background Appropriate and sufficient dietary intake is one of the main requirements for maintaining fitness and health. Inadequate energy intake may have a negative impact on physical performance which may result in injuries among physically active populations. The purpose of this research was to evaluate a possible relationship between dietary intake and stress fracture occurrence among combat recruits during basic training (BT. Methods Data was collected from 74 combat recruits (18.2 ± 0.6 yrs in the Israeli Defense Forces. Data analyses included changes in anthropometric measures, dietary intake, blood iron and calcium levels. Measurements were taken on entry to 4-month BT and at the end of BT. The occurrence of stress reaction injury was followed prospectively during the entire 6-month training period. Results Twelve recruits were diagnosed with stress fracture in the tibia or femur (SF group. Sixty two recruits completed BT without stress fractures (NSF. Calcium and vitamin D intakes reported on induction day were lower in the SF group compared to the NSF group-38.9% for calcium (589 ± 92 and 964 ± 373 mg·d-1, respectively, p -1, respectively, p Conclusions The development of stress fractures in young recruits during combat BT was associated with dietary deficiency before induction and during BT of mainly vitamin D and calcium. For the purpose of intervention, the fact that the main deficiency is before induction will need special consideration.

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

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


    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 st...

  7. Critical incident stress debriefing following traumatic life experiences.

    Irving, P; Long, A


    This study was designed to explore the use of critical incident stress debriefing as a therapeutic intervention following traumatic life events. A case study approach was used to allow the researchers to adopt a more flexible and overtly involved stance. Initial contact took place 24 h following the traumatic life experiences of three women. Critical incident stress debriefing was provided and data were collected and recorded within an ethical framework. Six months following the traumatic life experiences the women were interviewed again to explore their perceptions of the intervention that was provided. The results demonstrated positive outcomes. The women concluded that the debriefing intervention provided a safe forum for them to explore their needs, process their experiences and create constructive narratives. A carefully constructed critical incident stress debriefing intervention was used within the context of its objectives and acknowledged limitations. The study was small and generalizations cannot be made to other individuals who experience similar tragedies. Nevertheless, evidence from previous research coupled with the findings from this study suggests that mental health nurses might benefit from being educated and trained in critical incident stress debriefing. Further research needs to be carried out to explore the use of different models of stress debriefing applied to special circumstances. The goal of such interventions should be to alleviate symptoms and to prevent the development of a full-blown post-traumatic stress disorder.

  8. Age Related Incidence and Early Outcomes of Hip Fractures: A Prospective Cohort Study of 1177 patients

    Shenoy Ravikiran


    Full Text Available Abstract Introduction Associated with the increase in the aging population, there is an increase in the incidence of hip fractures worldwide. Outcome following such fractures is affected by age of the patient. This study aims to assess the incidence and early outcome of hip fractures, comparing between different age groups. Methods Data of hip fractures collected over a period of five years was analysed. Patients were divided into three groups, group A (patients under the age of 64, group B (patients between 65 and 84 years of age, and group C (patients over the age of 85. Results Of the 1177 patients included in the study, there were 90 patients in group A, 702 patients in group B and 385 patients in group C. There was a female preponderance across all age groups, and this increased as age advanced (p Conclusions Hip fractures are more common among females irrespective of age group. Older patients have a higher mortality and a greater deterioration of walking ability after such injuries. Internal fixation of intracapsular fractures have demonstrated satisfactory early outcome in the immediate period. This could be attributed to retention of native bone, better propioception and shorter operation time.

  9. Stress Fracture of the Ulna in an Elite Ice Dancer

    Davide Tornese


    Full Text Available Stress fracture of the ulna is a rare overuse injury often arising from repetitive excessive forearm rotation. Here we report the first case of ulnar stress fracture in a female ice dancer. Diagnosis was made by history and physical examination, with the aid of imaging studies (plain x-ray, computed tomography, and magnetic resonance imaging, and biomechanical analysis of forearm pronation and supination. Following identification and modification of the causal technical element, the ice dancer was able to continue training and competing without cessation of activity. Treatment was with a 30-day course of capacitively coupled bone stimulation to promote fracture healing, confirmed on radiography and magnetic resonance imaging. Such injuries to ice dancers may be prevented at the planning stage of technical elements in the dance program if coaches place more attention on the potentially deleterious effects of difficult positions the lifted dancer must sustain to reward points on the technical elements score.

  10. A Fracture Probability Competition Mechanism of Stress Corrosion Cracking

    Yanliang HUANG


    The stress corrosion cracking (SCC) of austenitic stainless steel was studied via polarization,slow strain rate and scanning electron microscope (SEM) techniques. Many SCC mechanisms have been proposed in which hydrogen embrittlement and passive film rupture-repassivation theories are generally accepted, but they can hardly explain the SCC mechanism of austenitic stainless steel in acidic chloride solution adequately, because the steel is in active dissolution state and cathodic polarization can prevent it from occurring. Our experiment shows that the anodic current increases the creep rate and decreases the plastic strength of the material on single smooth specimen as well as at the SCC crack tip. The fractured surface was characterized as brittle cleavage, while the surface crack of smooth specimen was almost vertical to the tensile strength, which can confirm that the cracks were caused by tensile stresses. A fracture probability competition mechanism of SCC was proposed on the basis of the experimental results combined with the viewpoint of ductile-brittle fracture competition. When the anodic dissolution current is increased to a certain degree, the probability of fracture by tensile stress will exceed that by shear stress, and the brittle fracture will occur. The proposed SCC mechanism can not only explain the propagation of SCC cracks but can explain the crack initiation as well. The strain on the surface distributes unevenly when a smooth specimen is deformed, so does the anodic current distribution. The crack will initiate at a point where the anodic current density is large enough to cause the material at a specific point to fracture in brittle manner.

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

    van der Giessen, Erik; Tvergaard, Viggo


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

  12. An Unusual Stress Fracture in an Archer with Hypophosphatasia

    Umut Yavuz


    Full Text Available We report a 45-year-old male archer with stress fracture in his left ulna on the background of adult type of hypophosphatasia. The patient presented to several medical centers for pain around the left elbow and received medical treatment upon diagnosis of tenosynovitis. History of the patient revealed that he had had diagnosis of hypophosphatasia ten years ago and underwent percutaneous screwing for stress fracture on both of his femoral necks. Upon finding nondisplaced stress fracture on proximal metaphysis of the ulna on X-ray, the patient underwent magnetic resonance imaging (MRI in order to exclude pathological causes. No additional pathology was observed in MRI scanning. The patient’s sportive activities were restricted for 6 weeks and he received conservative management with arm slings. Adult type of hypophosphatasia is a disease manifesting with widespread osteoporosis and presenting with low serum level of alkali phosphatase (ALP. Stress fracture should definitely be considered in the patients with history of hypophosphatasia and refractory extremity pain.

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

    Giessen, E. van der; Tvergaard, V.


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

  14. Incidence rates and trends of hip/femur fractures in five European countries

    Requena, G; Abbing-Karahagopian, V; Huerta, C


    Hip fractures represent a major public health challenge worldwide. Multinational studies using a common methodology are scarce. We aimed to estimate the incidence rates (IRs) and trends of hip/femur fractures over the period 2003-2009 in five European countries. The study was performed using seven...... electronic health-care records databases (DBs) from Denmark, The Netherlands, Germany, Spain, and the United Kingdom, based on the same protocol. Yearly IRs of hip/femur fractures were calculated for the general population and for those aged ≥50 years. Trends over time were evaluated using linear regression......, P femur fractures varied greatly across European countries. With the exception of Denmark, no decreasing trend was observed over the study period....

  15. Current and Future Incidence and Costs of Osteoporosis-Related Fractures in the Netherlands : Combining Claims Data with BMD Measurements

    F.J.B. Lötters (Freek); J.P.W. van den Bergh (Joop); F. de Vries (Frank); M.P.M.H. Rutten-van Mölken (Maureen)


    markdownabstractThis study aims to estimate the incidence and costs of osteoporosis-related fractures in The Netherlands in 2010 and project them to 2030. The incidence and costs of five different types of fractures (spine, hip, upper extremity, lower extremity, wrist/distal forearm, other) were der

  16. Current and Future Incidence and Costs of Osteoporosis-Related Fractures in the Netherlands : Combining Claims Data with BMD Measurements

    F.J.B. Lötters (Freek); J.P.W. van den Bergh (Joop); F. de Vries (Frank); M.P.M.H. Rutten-van Mölken (Maureen)


    markdownabstractThis study aims to estimate the incidence and costs of osteoporosis-related fractures in The Netherlands in 2010 and project them to 2030. The incidence and costs of five different types of fractures (spine, hip, upper extremity, lower extremity, wrist/distal forearm, other) were

  17. Current and Future Incidence and Costs of Osteoporosis-Related Fractures in The Netherlands: Combining Claims Data with BMD Measurements

    F.J.B. Lötters (Freek); J.P.W. van den Bergh (Joop); F. de Vries (Frank); M.P.M.H. Rutten-van Mölken (Maureen)


    textabstractThis study aims to estimate the incidence and costs of osteoporosis-related fractures in The Netherlands in 2010 and project them to 2030. The incidence and costs of five different types of fractures (spine, hip, upper extremity, lower extremity, wrist/distal forearm, other) were derived

  18. Emergency nurses' perceptions of critical incidents and stress debriefing.

    Burns, C; Harm, N J


    This is a descriptive study of questionnaire responses of 682 members of three state ENAs, with supporting interview data from 26 of those participants. The objective was to determine (1) the types of clinical events perceived as critical and (2) the usefulness of critical incident stress debriefings for emergency nurses. Questionnaires asking emergency nurses to rate clinical incidents as critical and to respond to questions about their experiences with debriefings were sent to members of three state ENAs. Structured interviews about personal experiences with critical incidents and debriefings were conducted with 26 respondents. Emergency nurses responding to the questionnaire viewed the death of a child and the death of a coworker as the most critical of the possible events. The majority of interviewees saw an incident related to the death of a child as the most critical in their careers. Of the questionnaire respondents, 32% had participated in debriefings; 88% of those found them helpful in reducing critical incident stress. The findings suggest that managers should be alerted to the possibility of acute stress responses when emergency nurses experience a child's death. Education regarding stress and debriefings may be helpful to ED personnel.

  19. Low incidence of flexion-type supracondylar humerus fractures but high rate of complications.

    Kuoppala, Eira; Parviainen, Roope; Pokka, Tytti; Sirviö, Minna; Serlo, Willy; Sinikumpu, Juha-Jaakko


    Background and purpose - Supracondylar humerus fractures are the most common type of elbow fracture in children. A small proportion of them are flexion-type fractures. We analyzed their current incidence, injury history, clinical and radiographic findings, treatment, and outcomes. Patients and methods - We performed a population-based study, including all children <16 years of age. Radiographs were re-analyzed to include only flexion-type supracondylar fractures. Medical records were reviewed and outcomes were evaluated at a mean of 9 years after the injury. In addition, we performed a systematic literature review of all papers published on the topic since 1990 and compared the results with the findings of the current study. Results - During the study period, the rate of flexion-type fractures was 1.2% (7 out of 606 supracondylar humeral fractures). The mean annual incidence was 0.8 per 105. 4 fractures were multidirectionally unstable, according to the Gartland-Wilkins classification. All but 1 were operatively treated. Reduced range of motion, changed carrying angle, and ulnar nerve irritation were the most frequent short-term complications. Finally, in the long-term follow-up, mean carrying angle was 50% more in injured elbows (21°) than in uninjured elbows (14°). 4 patients of the 7 achieved a satisfactory long-term outcome according to Flynn's criteria. Interpretation - Supracondylar humeral flexion-type fractures are rare. They are usually severe injuries, often resulting in short-term and long-term complications regardless of the original surgical fixation used.

  20. Correlation between porous structure and fracture stress for metallurgical coke

    Gardien, J.F.; Lemaire, E.; Dubs, A.; Osmont, P.; Laurent, J.P.; Steiler, J.M. (Institut de Recherches de la Siderurgie Francaise, Maizieres-les-Metz (France))


    Various samples of coke have been characterized by diametral compression and the geometry of the porous network has been analysed in terms of fractal structure. It is found that the coke studied exhibits a fractal behaviour on at least two decades. Diametral compression test leads to two different ways of breaking; brittle fracture, and in some cases complex fracture. As expected, the fracture stress is not linked with the fractal dimension in case of brittle fracture, but with the mean size of the largest pores. In case of complex loading conditions, the fracture strength is linked with the fractal dimension. The models of Cook and of Anderson, which integrate fractal description of porous materials in Griffith's theory, do not seem to be valid concerning coke material. The present approach of characterising the porous structure of coke by the fractal dimension seems adapted to explain coke strength, especially under complex stress conditions, but should be extended to an increased number of coke type samples.

  1. Prediction of Incident Major Osteoporotic and Hip Fractures by Trabecular Bone Score (TBS) and Prevalent Radiographic Vertebral Fracture in Older Men.

    Schousboe, John T; Vo, Tien; Taylor, Brent C; Cawthon, Peggy M; Schwartz, Ann V; Bauer, Douglas C; Orwoll, Eric S; Lane, Nancy E; Barrett-Connor, Elizabeth; Ensrud, Kristine E


    Trabecular bone score (TBS) has been shown to predict major osteoporotic (clinical vertebral, hip, humerus, and wrist) and hip fractures in postmenopausal women and older men, but the association of TBS with these incident fractures in men independent of prevalent radiographic vertebral fracture is unknown. TBS was estimated on anteroposterior (AP) spine dual-energy X-ray absorptiometry (DXA) scans obtained at the baseline visit for 5979 men aged ≥65 years enrolled in the Osteoporotic Fractures in Men (MrOS) Study and its association with incident major osteoporotic and hip fractures estimated with proportional hazards models. Model discrimination was tested with Harrell's C-statistic and with a categorical net reclassification improvement index, using 10-year risk cutpoints of 20% for major osteoporotic and 3% for hip fractures. For each standard deviation decrease in TBS, there were hazard ratios of 1.27 (95% confidence interval [CI] 1.17 to 1.39) for major osteoporotic fracture, and 1.20 (95% CI 1.05 to 1.39) for hip fracture, adjusted for FRAX with bone mineral density (BMD) 10-year fracture risks and prevalent radiographic vertebral fracture. In the same model, those with prevalent radiographic vertebral fracture compared with those without prevalent radiographic vertebral fracture had hazard ratios of 1.92 (95% CI 1.49 to 2.48) for major osteoporotic fracture and 1.86 (95% CI 1.26 to 2.74) for hip fracture. There were improvements of 3.3%, 5.2%, and 6.2%, respectively, of classification of major osteoporotic fracture cases when TBS, prevalent radiographic vertebral fracture status, or both were added to FRAX with BMD and age, with minimal loss of correct classification of non-cases. Neither TBS nor prevalent radiographic vertebral fracture improved discrimination of hip fracture cases or non-cases. In conclusion, TBS and prevalent radiographic vertebral fracture are associated with incident major osteoporotic fractures in older men independent of each other

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

    Vu Trang


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

  3. C2 Fracture Subtypes, Incidence, and Treatment Allocation Change with Age: A Retrospective Cohort Study of 233 Consecutive Cases

    Anna-Lena Robinson; Anders Möller; Yohan Robinson; Claes Olerud


    The currently available data on the distribution of C2 fracture subtypes is sparse. This study was designed to identify the proportions of the second cervical vertebra (C2) fracture subtypes and to present age and gender specific incidences of subgroups. A dataset of all patients treated between 2002 and 2014 for C2 fractures was extracted from the regional hospital information system. C2 fractures were classified into odontoid fractures types 1, 2, and 3, Hangman’s fractures types 1, 2, and ...

  4. Composite fracture using the normal stress ratio theory

    Beuth, J. L., Jr.; Gurdal, Z.; Herakovich, C. T.


    Experiments were performed on center-notched specimens of unidirectional AS4/3501-6 graphite-epoxy subjected to varied far-field loading conditions. Specimens tested include on-axis and off-axis tensile coupons and Iosipescu shear specimens, allowing the study of normal, shear, and combined far-field loading conditions. From the tests, the direction of initial crack extension and the far-field stresses at crack initiation and fracture are obtained. The normal stress ratio theory is subsequently applied within a macroscopic-level homogeneous anisotropic stress solution to predict the direction of crack extension, critical stresses, and other crack growth behavior for the experiments. Comparison between experimental results and theoretical predictions indicates that application of the normal stress ratio theory within a macroscopic-level stress analysis has significant potential as an approach to modeling composite crack growth.

  5. Incidence and clinical significance of zygomaticomaxillary complex fracture involving the temporomandibular joint with emphasis on trismus

    Chia-Ming Chang


    Full Text Available Trismus is frequently a sequel of temporomandibular joint (TMJ involvement in a zygomaticomaxillary complex (ZMC fracture. Although trismus is commonly observed in patients with ZMC fracture, continuous follow-up examinations of their degree of mouth opening have rarely been documented. The aim of this retrospective study was to determine the incidence and clinical significance of ZMC fracture involving the glenoid fossa or articular eminence of the TMJ with an emphasis on trismus. The medical and computed tomography (CT imaging data of 28 patients with ZMC fracture treated by oral and maxillofacial surgeons (OMFSs (OMFS group and 174 patients with ZMC fracture treated by surgeons other than OMFSs (non-OMFS group between May 2002 and May 2006 were reviewed. Maximal interincisal opening (MIO less than 35 mm or three-finger width was considered limited mouth opening and indicative of trismus. Preoperative CT imaging data indicated that about 64% (18/28 and 50% (87/174 of the patients in the OMFS and non-OMFS groups, respectively, had a ZMC fracture involving the TMJ. Among these OMFS patients, 17 (94.40% patients had limited mouth opening (MIO range, 7–33 mm preoperatively, which improved markedly postoperatively. Among the non-OMFS patients with such fractures, 42 (48.3% patients had trismus preoperatively and two retained trismus postoperatively. Lack of proper preoperative CT images, inadequate postoperative follow-up protocol, and/or neglect by patients and medical staff could influence the outcomes of ZMC fracture involving the TMJ. We make recommendations for reducing the risk of complications subsequent to ZMC fracture involving the TMJ.

  6. Incidence and clinical significance of zygomaticomaxillary complex fracture involving the temporomandibular joint with emphasis on trismus.

    Chang, Chia-Ming; Ko, Edward C; Kao, Chu-Chiang; Chang, Pei-Ying; Chen, Michael Y C


    Trismus is frequently a sequel of temporomandibular joint (TMJ) involvement in a zygomaticomaxillary complex (ZMC) fracture. Although trismus is commonly observed in patients with ZMC fracture, continuous follow-up examinations of their degree of mouth opening have rarely been documented. The aim of this retrospective study was to determine the incidence and clinical significance of ZMC fracture involving the glenoid fossa or articular eminence of the TMJ with an emphasis on trismus. The medical and computed tomography (CT) imaging data of 28 patients with ZMC fracture treated by oral and maxillofacial surgeons (OMFSs) (OMFS group) and 174 patients with ZMC fracture treated by surgeons other than OMFSs (non-OMFS group) between May 2002 and May 2006 were reviewed. Maximal interincisal opening (MIO) less than 35 mm or three-finger width was considered limited mouth opening and indicative of trismus. Preoperative CT imaging data indicated that about 64% (18/28) and 50% (87/174) of the patients in the OMFS and non-OMFS groups, respectively, had a ZMC fracture involving the TMJ. Among these OMFS patients, 17 (94.40%) patients had limited mouth opening (MIO range, 7-33 mm) preoperatively, which improved markedly postoperatively. Among the non-OMFS patients with such fractures, 42 (48.3%) patients had trismus preoperatively and two retained trismus postoperatively. Lack of proper preoperative CT images, inadequate postoperative follow-up protocol, and/or neglect by patients and medical staff could influence the outcomes of ZMC fracture involving the TMJ. We make recommendations for reducing the risk of complications subsequent to ZMC fracture involving the TMJ. Copyright © 2012. Published by Elsevier B.V.

  7. The incidence of secondary vertebral fracture of vertebral augmentation techniques versus conservative treatment for painful osteoporotic vertebral fractures: a systematic review and meta-analysis.

    Song, Dawei; Meng, Bin; Gan, Minfeng; Niu, Junjie; Li, Shiyan; Chen, Hao; Yuan, Chenxi; Yang, Huilin


    Percutaneous vertebroplasty (PVP) and balloon kyphoplasty (BKP) are minimally invasive and effective vertebral augmentation techniques for managing osteoporotic vertebral compression fractures (OVCFs). Recent meta-analyses have compared the incidence of secondary vertebral fractures between patients treated with vertebral augmentation techniques or conservative treatment; however, the inclusions were not thorough and rigorous enough, and the effects of each technique on the incidence of secondary vertebral fractures remain unclear. To perform an updated systematic review and meta-analysis of the studies with more rigorous inclusion criteria on the effects of vertebral augmentation techniques and conservative treatment for OVCF on the incidence of secondary vertebral fractures. PubMed, MEDLINE, EMBASE, SpringerLink, Web of Science, and the Cochrane Library database were searched for relevant original articles comparing the incidence of secondary vertebral fractures between vertebral augmentation techniques and conservative treatment for patients with OVCFs. Randomized controlled trials (RCTs) and prospective non-randomized controlled trials (NRCTs) were identified. The methodological qualities of the studies were evaluated, relevant data were extracted and recorded, and an appropriate meta-analysis was conducted. A total of 13 articles were included. The pooled results from included studies showed no statistically significant differences in the incidence of secondary vertebral fractures between patients treated with vertebral augmentation techniques and conservative treatment. Subgroup analysis comparing different study designs, durations of symptoms, follow-up times, races of patients, and techniques were conducted, and no significant differences in the incidence of secondary fractures were identified (P > 0.05). No obvious publication bias was detected by either Begg's test (P = 0.360 > 0.05) or Egger's test (P = 0.373 > 0.05). Despite current thinking in the

  8. Critical Incident Stress Debriefing for Health Care Workers.

    Lane, Pamela S.


    Describes Critical Incident Stress Debriefing process (CISD) as model designed to mitigate impact of life-threatening crises on health care workers, to facilitate their return to routine functioning, and to prevent pathological responses to trauma that is inherent aspect of their profession. Examines development of CISD and explores its…

  9. Stress fracture injury in young military men and women.

    Armstrong, David W; Rue, John-Paul H; Wilckens, John H; Frassica, Frank J


    Approximately 5% of all military recruits incur stress fracture injuries during intense physical training, predominately in the lower extremity. We compared young men and women with stress fracture injury (subjects) to a matched group of uninjured volunteers (controls) during a summer training program at the United States Naval Academy to identify possible risk factors for stress fracture injury. The subject group was composed of 13 female and 18 male plebes with training-induced stress fracture injury verified by plain radiographs and/or nuclear bone scan. The control group was composed of 13 female and 18 male plebes who remained without injury during plebe summer training but who were matched with the 31 injured plebes for the Initial Strength Test (1-mi run time, means: women, 7.9 min; men, 6.4 min) and body mass index (means: women, 23.4; men, 23.8). We found that the subjects lost significant body weight (mean, 2.63 +/- 0.54 kg) between Day 1 and the date of their diagnosis of a stress fracture (mean, Day 35) and that they continued to lose weight until the date of their DEXA scan (mean, Day 49). Among female plebes, there was no evidence of the female athlete triad (eating disorders, menstrual dysfunction, or low bone density). Thigh girth was significantly smaller in female subjects than in female controls and trended to be lower in male subjects than in male controls. Total body bone mineral content was significantly lower in the male subjects than in male controls. Bone mineral density of the distal tibia and femoral neck were not significantly different between the groups. DEXA-derived structural geometric properties were not different between subjects and controls. Because, on average, tibias were significantly longer in male subjects than in male controls, the mean bone strength index in male subjects was significantly lower than that of male controls. We conclude that significant, acute weight loss combined with regular daily physical training among

  10. Sequential Proximal Tibial Stress Fractures associated with Prolonged usage of Methotrexate and Corticosteroids: A Case Report

    Tan TJL


    Full Text Available Stress fractures of the proximal tibia metaphysis are rare in the elderly. We present a case of a 65-year old male who developed sequential proximal tibia stress fractures associated with prolonged usage of methotrexate and prednisolone within a span of 18 months. Magnetic Resonance Imaging revealed an incomplete stress fracture involving the medial proximal tibial region. The patient was treated with stemmed total knee arthroplasty (TKA bilaterally. Stress fractures should be considered in patients with atypical knee pain who have a history of methotrexate and prednisolone usage. TKA is an effective treatment in stress fractures of the proximal tibia.

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

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


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

  12. Optimization of Multi-Cluster Fracturing Model under the Action of Induced Stress in Horizontal Wells

    Shanyong Liu


    Full Text Available Volume fracturing in shale gas forms complex fracture networks and increases stimulated reservoir volume through large-scale fracturing operation with plug-perforation technology. However, some perforation clusters are stimulated unevenly after fracturing. This study aims to solve this problem by analyzing the shortcomings of the conventional fracturing model and developing a coupled model based on the 2D fracture motion equation, energy conservation law, linear elastic mechanics, and stress superposition principle. First, a multi-fracture in-situ stress model was built by studying the induced stress produced by the fracture initiation to deduce the multi-fracture induced stress impact factor on the basis of the stress superposition principle. Then, the classical Perkins–Kern–Nordgren model was utilized with the crustal stress model. Finally, a precise fracturing design method was used to optimize perforation and fracturing parameters under the new model. Results demonstrate that the interference effect among fractures is the major factor causing the non-uniform propagation of each fracture. Compression on the main horizontal stress increases the net pressure. Therefore, both the degree of operation difficulty and the complexity of fracture geometry are improved. After applying the optimal design, the production is increased by 20%, and the cost is reduced by 15%.

  13. Older men with low serum IGF-1 have an increased risk of incident fractures: the MrOS Sweden study.

    Ohlsson, Claes; Mellström, Dan; Carlzon, Daniel; Orwoll, Eric; Ljunggren, Osten; Karlsson, Magnus K; Vandenput, Liesbeth


    Osteoporosis-related fractures constitute a major health concern not only in women but also in men. Insulin-like growth factor 1 (IGF-1) is a key determinant of bone mass, but the association between serum IGF-1 and incident fractures in men remains unclear. To determine the predictive value of serum IGF-1 for fracture risk in men, older men (n = 2902, mean age of 75 years) participating in the prospective, population-based Osteoporotic Fractures in Men (MrOS) Sweden study were followed for a mean of 3.3 years. Serum IGF-1 was measured at baseline by radioimmunoassay. Fractures occurring after the baseline visit were validated. In age-adjusted hazards regression analyses, serum IGF-1 associated inversely with risk of all fractures [hazard ratio (HR) per SD decrease = 1.23, 95% confidence interval (CI) 1.07-1.41], hip fractures (HR per SD decrease = 1.45, 95% CI 1.07-1.97), and clinical vertebral fractures (HR per SD decrease = 1.40, 95% CI 1.10-1-78). The predictive role of serum IGF-1 for fracture risk was unaffected by adjustment for height, weight, prevalent fractures, falls, and major prevalent diseases. Further adjustment for bone mineral density (BMD) resulted in an attenuated but still significant association between serum IGF-1 and fracture risk. Serum IGF-1 below but not above the median was inversely related to fracture incidence. The population-attributable risk proportion was 7.5% for all fractures and 22.9% for hip fractures. Taken together, older men with low serum IGF-1 have an increased fracture risk, especially for the two most important fracture types, hip and vertebral fractures. The association between serum IGF-1 and fracture risk is partly mediated via BMD.

  14. Self-reported versus diagnosed stress fractures in norwegian female elite athletes.

    Oyen, Jannike; Torstveit, Monica Klungland; Sundgot-Borgen, Jorunn


    The aim of this study was to determine the prevalence of self- reported versus diagnosed stress fractures in female elite athletes and non-athletic controls. A random sample of Norwegian elite athletes from the national teams, aged 13-39 years (n = 186) and a random sample of non-athletic controls (n = 145) in the same age group participated in the study. The athletes represented a junior- or senior team, or a recruiting squad for one of these teams, in one of 46 different sports/events. A higher percentage of athletes self-reported stress fractures (14.0%) compared to those diagnosed with stress fractures (8.1%) (p stress fractures, but none of them were diagnosed with stress fractures. These results indicate that self-reporting of stress fractures has low validity. This finding has important implications for further research on stress fractures in athletes. Key pointsThis study is the first to compare self-reported and diagnosed stress fractures in the total population of elite athletes representing all kinds of sports.The results indicate that self-reporting of stress fractures has low validity in both athletes and non-athletic controls, and other measurement methods should be considered when evaluating possible stress fractures.Based on our results, stress fractures seem to be a sport-related injury.

  15. Incidence and risk of work-related fracture injuries: experience of a state-managed workers' compensation system.

    Islam, S S; Biswas, R S; Nambiar, A M; Syamlal, G; Velilla, A M; Ducatman, A M; Doyle, E J


    Incidence rates of occupational fractures at various anatomic sites and associated risk factors have not been well documented. We identified 3490 work-related fractures from a West Virginia Workers Compensation database that occurred between July 1, 1994, and June 30, 1995. The annual incidence rate was 55 per 10,000 workers, which is substantially higher than the work-related fracture rates reported previously. The incidence rate of fracture was highest in the agricultural sector, followed by the mining, construction, and manufacturing sectors (202.0, 165.2, 116.7, and 88.0 per 10,000 workers, respectively). The age-specific gender distribution comparing fracture and non-fracture injuries showed a bimodal distribution, with greater proportions of female employees at the younger and older age groups. Fracture of the phalanges was the most common, followed by fractures of the foot bone and carpal bone (15.8, 9.5, and 7.9 per 10,000 workers, respectively). In a multiple logistic regression analysis, age, gender, occupation, caught in-between objects, fall, struck by or against object, and vehicle collision were significant independent predictors of fracture (all sites combined). We believe work-related fractures to be a bigger problem than previously reported. The association among gender, age, occupation, and causes of fractures identified in this study will be useful in developing gender- and occupation-specific prevention intervention.

  16. Stress- and Chemistry-Mediated Permeability Enhancement/Degradation in Stimulated Critically-Stressed Fractures

    Derek Elsworth; Abraham S. Grader; Chris Marone; Phillip Halleck; Peter Rose; Igor Faoro; Joshua Taron; André Niemeijer; Hideaki Yasuhara


    This work has investigated the interactions between stress and chemistry in controlling the evolution of permeability in stimulated fractured reservoirs through an integrated program of experimentation and modeling. Flow-through experiments on natural and artificial fractures in Coso diorite have examined the evolution of permeability under paths of mean and deviatoric stresses, including the role of dissolution and precipitation. Models accommodating these behaviors have examined the importance of incorporating the complex couplings between stress and chemistry in examining the evolution of permeability in EGS reservoirs. This document reports the findings of experiment [1,2] and analysis [3,4], in four sequential chapters.

  17. Oncogenic osteomalacia presenting as bilateral stress fractures of the tibia

    Ohashi, Kenjirou; Ohnishi, Takeshi; Ishikawa, Tohru [Department of Radiology, St. Marianna University Hospital, Kanagawa (Japan); Tani, Haruo [Department of Internal Medicine III, St. Marianna University Hospital, Kawasaki City, Kanagawa (Japan); Uesugi, Keisuke [Department of Otolaryngology, St. Marianna University Hospital, Kawasaki City, Kanagawa (Japan); Takagi, Masayuki [Department of Pathology, St. Marianna University Hospital, Kawasaki City, Kanagawa (Japan)


    We report on a patient with bilateral stress fractures of the tibia who subsequently showed classic biochemical features of oncogenic osteomalacia. Conventional radiographs were normal. MR imaging revealed symmetric, bilateral, band-like low-signal lesions perpendicular to the medial cortex of the tibiae and corresponding to the only lesions subsequently seen on the bone scan. A maxillary sinus lesion was subsequently detected and surgically removed resulting in prompt alleviation of symptoms and normalization of hypophosphatemia and low 1,25-(OH){sub 2} vitamin D{sub 3}. The lesion was pathologically diagnosed as a hemangiopericytoma-like tumor. Patients with oncogenic osteomalacia may present with stress fractures limited to the tibia, as seen in athletes. The clue to the real diagnosis lies in paying close attention to the serum phosphate levels, especially in patients suffering generalized symptoms of weakness and not given to unusual physical activity. (orig.) With 4 figs., 6 refs.

  18. Anisotropy effect on the stress-based fracture forming limit diagram using a modified Lou-Huh ductile fracture criterion

    Park, Namsu; Huh, Hoon


    This paper is concerned with the anisotropy effect on the stress-based fracture forming limit diagram using a modified Lou-Huh ductile fracture criterion. In sheet metal forming process, a usage of advanced high-strength steels (AHSSs) has been remarkably increasing for the lightweight car body and good formability. It is, however, unable to evaluate the formability of AHSS with the conventional forming limit diagram during complex forming processes since it is obtained by assuming the proportional loading path and AHSS shows sudden fracture involving little amount of necking. The stress-based fracture forming limit diagram was constructed using a modified Lou-Huh ductile fracture criterion in order to evaluate the formability of AHSS accurately. The anisotropy effect on the fracture strain is also evaluated to reflect the material behavior of sheet metals in constructing the criterion for the prediction of onset of the fracture. The constructed stress-based fracture forming limit diagrams deal with the stress state ranging from pure shear to equi-biaxial tension with the variation of orientation of sheet metals. It is clearly observed that the stress-based fracture forming limit diagrams are varied with the change of orientation of sheet metals.

  19. [Stress reactions--stress fracture of the upper femoral neck in endurance sports].

    Schultz, W; Stinus, H; Schleicher, W; Hess, T


    Stress reactions of the musculoskeletal system may be interpreted as possible precursors of stress fractures. Biological material, in contrast to artificial products, can react in numerous and complex ways. This can not only lead to a continual weakening of the tissue, but also to adaptation phenomena in response to overuse. The causes of such stress reactions are still unclear in many respects. For example, it is unknown to what extent a predisposition to these stress symptoms is created by mechanical stress alone or whether other factors such as physical condition, nutrition or even hormone balance come into play. Early diagnosis considerably reduces the healing process and, the later the diagnosis of the stress reaction, the more drawn out is the healing process and the extent of the athlete's absence from training. In this connection may be discussed whether the stress reaction can be the represent as the precursor of the stress fracture. In light of the need for taking special care in obtaining anamnestic data and determining the predisposition of an athlete, it appears to be justified to perform whole body bone scanning in the initial stages and particularly after an innocuous radiological finding. To what extent more current methods (e. g. MRI) can be applied without exposing the athlete to undue radiation cannot be conclusively judged at present. The treatment of a stress reaction should, at least at the beginning, be the same as for a diagnosed stress fracture.

  20. Frequent manual repositioning and incidence of pressure ulcers among bed-bound elderly hip fracture patients.

    Rich, Shayna E; Margolis, David; Shardell, Michelle; Hawkes, William G; Miller, Ram R; Amr, Sania; Baumgarten, Mona


    Frequent manual repositioning is an established part of pressure ulcer prevention, but there is little evidence for its effectiveness. This study examined the association between repositioning and pressure ulcer incidence among bed-bound elderly hip fracture patients, using data from a 2004-2007 cohort study in nine Maryland and Pennsylvania hospitals. Eligible patients (n=269) were age ≥ 65 years, underwent hip fracture surgery, and were bed-bound at index study visits (during the first 5 days of hospitalization). Information about repositioning on the days of index visits was collected from patient charts; study nurses assessed presence of stage 2+ pressure ulcers 2 days later. The association between frequent manual repositioning and pressure ulcer incidence was estimated, adjusting for pressure ulcer risk factors using generalized estimating equations and weighted estimating equations. Patients were frequently repositioned (at least every 2 hours) on only 53% (187/354) of index visit days. New pressure ulcers developed at 12% of visits following frequent repositioning vs. 10% following less frequent repositioning; the incidence rate of pressure ulcers per person-day did not differ between the two groups (incidence rate ratio 1.1, 95% confidence interval 0.5-2.4). No association was found between frequent repositioning of bed-bound patients and lower pressure ulcer incidence, calling into question the allocation of resources for repositioning.

  1. Stress fracture in the world class athlete: a case study.

    Jensen, J E


    Stress fracture presents a difficult problem in the high performance, world-class athlete. Competitive demands provide little tolerance for, or agreement with, prolonged periods of rest which are the first line of conservative treatment methods. The use of a specifically programmed, pulsed, low-intensity ultrasound device to shorten the time of healing was investigated in a well-known gymnast with an Olympic deadline. Prior animal, in vitro, and clinical studies had established the safety and effectiveness of this device in fractures. The location of the stress injury was in the mid-tibia which is considered to present the greatest challenge to an early healing result. The low-intensity ultrasound device was prescribed for daily use at home. At 3 wk after the start of low-intensity ultrasound, the stress fracture responded well and the patient was allowed use of tumble track, trampoline, and to do some weight-bearing activities, such as jumping in the pool and loading-type activities. At 4.5 wk, the patient progressed to full workout activities and participated in a trial meet for the Olympics. At 6 wk, the patient's participation in the women's gymnastic team event was a factor in the United States receiving a gold medal.

  2. Experimental study on water seepage constitutive law of fracture in rock under 3D stress

    赵阳升; 杨栋; 郑少河; 胡耀青


    The test method and test result of water seepage constitutive law of fracture in rock under 3D stress are introduced. A permeability coefficient formula including the coefficient of fracture connection, normal stiffness, 3D stress, initial width of fracture and Poisson ratio is presented based on the analysis of the test theory and its result.

  3. Maximum twin shear stress factor criterion for sliding mode fracture initiation

    黎振兹; 李慧剑; 黎晓峰; 周洪彬; 郝圣旺


    Previous researches on the mixed mode fracture initiation criteria were mostly focused on opening mode fracture. In this study, the authors proposed a new criterion for mixed mode sliding fracture initiation, which is the maximum twin shear stress factor criterion. The authors studied a finite width plate with central slant crack, subject to a far-field uniform uniaxial tensile or compressive stress.

  4. Stressful life events and incident metabolic syndrome: the Hoorn study.

    Rutters, Femke; Pilz, Stefan; Koopman, Anitra D M; Rauh, Simone P; Pouwer, Frans; Stehouwer, Coen D A; Elders, Petra J; Nijpels, Giel; Dekker, Jacqueline M


    Stressful life events are associated with the metabolic syndrome in cross-sectional studies, but prospective studies addressing this issue are rare and limited. We therefore evaluated whether the number of stressful life events is associated with incident metabolic syndrome. We assessed the association between the number of stressful life events experienced in the 5 years up until baseline and incident metabolic syndrome after 6.5 years at follow-up in the Hoorn study, a middle-aged and elderly population-based cohort. Participants with prevalent metabolic syndrome at baseline were excluded. Metabolic syndrome was defined according to the Adult Treatment Panel III, including fasting plasma glucose levels, HDL-C levels, triglyceride levels, waist circumference and hypertension. We included 1099 participants (47% male; age 60 ± 7 years). During 6.5 years of follow-up, 238 participants (22%) developed the metabolic syndrome. Logistic regression adjusted for age, sex, education level and follow-up duration showed a positive association between the number of stressful life events at baseline and incident metabolic syndrome [OR 1.13 (1.01-1.27) per event, p = 0.049]. In addition, a Poisson model showed a significant positive association between the number of stressful life events at baseline and the number of metabolic syndrome factors at follow-up [OR 1.05 (1.01-1.11) per event, p = 0.018]. Finally, we observed a significant association between the number of stressful life events at baseline and waist circumference at follow-up [adjusted for confounders β 0.86 (0.39-1.34) cm per event, p metabolic syndrome during 6.5 years of follow-up, in a middle-aged and elderly population-based cohort.

  5. Relationship between change in femoral neck bone mineral density and hip fracture incidence during treatment with strontium ranelate.

    Bruyère, O; Roux, C; Badurski, J; Isaia, G; de Vernejoul, M C; Cannata, J; Ortolani, S; Slosman, D; Detilleux, J; Reginster, J-Y


    Strontium ranelate (SR) increases bone mineral density (BMD) in postmenopausal osteoporotic women and reduces vertebral and non-vertebral fracture incidence. Hip fracture reduction has also been observed during 3-year treatment with SR in osteoporotic women at high risk of hip fracture. The objective of this study is to analyse the association between BMD changes and hip fracture incidence during treatment with SR. In this post-hoc analysis, 465 women aged over 74 years with low BMD at the femoral neck (T-score TROPOS). BMD was assessed at the femoral neck at baseline and after a follow-up of 3 years. Hip fractures were reported by study investigators. After adjusting for age, body mass index, femoral neck BMD at baseline and number of prevalent vertebral fractures, we found that for each 1% increase in femoral neck BMD observed after 3 years, the risk to experience a hip fracture after 3 years decreased by 7% (95% CI: 1-14%) (p = 0.04). In patients experiencing a hip fracture over 3 years of treatment with SR, femoral neck BMD increased by (mean [SE]) 3.41 (1.02)% compared to 7.23 (0.81)% in patients without hip fracture (p = 0.02). In this post-hoc analysis of women undergoing 3 years of SR treatment, an increase in femoral neck BMD is associated with a decrease in hip fracture incidence.

  6. Case report of critical incident stress debriefing through translators.

    True, P K


    The United States Navy has SPRINT (Special Psychiatric Rapid Intervention Team) teams stationed in National Naval Medical Center in Bethesda, Maryland, Naval Regional Medical Center in Portsmouth, Virginia, Naval Regional Medical Center in San Diego, California, and US Naval Hospital, Bremerton, Washington. These teams are large units of psychiatrists, psychologists, nurses, chaplains, and hospital corpsmen who are trained in the techniques of Critical Incident Stress using the model developed by Jeffrey T. Mitchell and George S. Everly, Jr. (Mitchell & Everly, 1996; Everly & Mitchell, 1999). In addition to these large SPRINT teams, smaller Critical Incident Stress Management (CISM) teams exist at several Navy commands, including US Naval Hospital, Jacksonville, Florida. Since the formation of SPRINT teams, there have been several hundred interventions done at various military sites. This article discusses an intervention that was particularly unusual in that it was done by US military personnel for the members of the Argentine military, none of whom could speak English.

  7. Navicular Stress Fracture Outcomes in Athletes: Analysis of 62 Injuries.

    Saxena, Amol; Behan, Shontal A; Valerio, Dallas L; Frosch, Dominick L

    The optimal treatment modalities for navicular stress fractures in athletes is currently unknown for this season-ending injury. The present study evaluated factors that might be significant and affect healing outcomes, specifically focusing on the return to activity (RTA) time and a decreased desired activity (DDA) after treatment in athletes. Such considerations included previous navicular stress fractures, patient demographic data and type of sport, and initiation time of treatment. The data from 59 patients with 62 fractures were prospectively analyzed from May 2005 through July 2016. The results showed a significant correlation between a previous navicular stress fracture and decreased desired activity. The average duration of symptoms before receiving definitive treatment was 8.8 months. Computed tomography as the initial imaging modality correlated positively with a correct diagnosis (1.00). In contrast, magnetic resonance imaging, when used initially, was only 71% accurate. Runners constituted most of the cohort at 38 (61.3%). Ten other athletes were involved in jumping sports. Of the 62 injuries, 21 (33.9%) were in elite or professional athletes, all of whom were able to RTA, with 1 patient, a 38-year-old world record holding runner, having a DDA. Seven refractures (11.2%) occurred an average >5 years after the initial injury, predominantly in those aged <21 years, none with previous surgery. Eight patients (12.9%) developed postinjury arthrosis, including 1 with DDA. Patients who underwent open reduction and internal fixation had a RTA of 4.56 months compared with those who had undergone nonoperative treatment, who had an average RTA of 3.97 months. Seven patients (11.2%) underwent screw removal and required a longer RTA. Overall, of the 62 injuries, the patients with 57 of the injuries (91.9%) were able to RTA at their preinjury level. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  8. Critical incident stress intervention following fatal aircraft mishaps.

    Cigrang, J A; Pace, J V; Yasuhara, T T


    This article offers guidelines for conducting preventive mental health interventions using a Critical Incident Stress Debriefing (CISD) model with Air Force and other aviation communities that have experienced a fatal aircraft mishap. The guidelines are based on the authors' experiences in providing assistance to several hundred active duty military personnel and their families following two separate mishaps. The article outlines the basics of the CISD model, briefly describes the two mishaps, and then discusses the lessons learned.

  9. Critical incident stress debriefing (CISD): a meta-analysis.

    Everly, G S; Boyle, S H


    Psychological debriefings represent a genre of group crisis interventions. Critical Incident Stress Debriefing (CISD) represents the oldest standardized variation of this genre. Recent reviews have called into question the effectiveness of CISD. In this study 5 previously published investigations were meta-analyzed revealing a large effect size (Cohen's d = .86) supporting the notion that the CISD model of psychological debriefing is an effective crisis intervention.

  10. Effect of electric field, stress and environment on delayed fracture of a PZT-5 ferroelectric ceramic

    WANG; Yi; SU; Yanjing; CHU; Wuyang; QIAO; Lijie


    The combined effect of electric and mechanical loading on fracture of a PZT-5 ferroelectric ceramic in silicone oil has been investigated using a single edge notched specimen. The results show that the fracture toughness and the threshold stress intensity factor of delayed fracture in silicone oil, i.e. stress corrosion cracking, decrease linearly with the increasing applied electric field, either positive or negative. For the PZT-5 ferroelectric ceramics, delayed fracture in silicone oil under sustained positive or negative field can occur, and the threshold field for delayed fracture under sustained positive or negative field decreases linearly with applied stress intensity factor. The combined effect of electric and mechanical loading on delayed fracture in silicone oil includes fieldenhancing delayed fracture under sustained load and stress-enhancing delayed fracture in silicone oil under sustained field.

  11. Stress analysis of fracture of atherosclerotic plaques: crack propagation modeling.

    Rezvani-Sharif, Alireza; Tafazzoli-Shadpour, Mohammad; Kazemi-Saleh, Davood; Sotoudeh-Anvari, Maryam


    Traditionally, the degree of luminal obstruction has been used to assess the vulnerability of atherosclerotic plaques. However, recent studies have revealed that other factors such as plaque morphology, material properties of lesion components and blood pressure may contribute to the fracture of atherosclerotic plaques. The aim of this study was to investigate the mechanism of fracture of atherosclerotic plaques based on the mechanical stress distribution and fatigue analysis by means of numerical simulation. Realistic models of type V plaques were reconstructed based on histological images. Finite element method was used to determine mechanical stress distribution within the plaque. Assuming that crack propagation initiated at the sites of stress concentration, crack propagation due to pulsatile blood pressure was modeled. Results showed that crack propagation considerably changed the stress field within the plaque and in some cases led to initiation of secondary cracks. The lipid pool stiffness affected the location of crack formation and the rate and direction of crack propagation. Moreover, increasing the mean or pulse pressure decreased the number of cycles to rupture. It is suggested that crack propagation analysis can lead to a better recognition of factors involved in plaque rupture and more accurate determination of vulnerable plaques.

  12. Seepage properties of a single rock fracture subjected to triaxial stresses


    Coupled properties of seepage and stress fields of rock fractures greatly influence the safety of geotechnical engineering work.Based on the closing defomation principle of a single rock fracture,equations describing relationships of aperture and triaxial stresses are developed,and coupled models of seepage and triaxial stresses are proposed.Seepage tests are conducted under triaxial stress conditions by adopting hard granite specimens with an artificial fracture.The results show that the normal stress,lateral stress and seepage pressure significantly affect the flow behavior of rock fractures,and that hydraulic conductivity decreases with increasing normal.stress,but increases with rising lateral stress or seepage pressure.In addition,an exponential function provides a good representation of the seepage characteristics of a single rock fracture subjected to triaxial stresses.

  13. Incidence, Morbidity and Mortality in Patients Older than 50 Years with Second Hip Fracture in a Jeju Cohort Study

    Park, Yong-Geun; Jang, Sunmee; Ha, Yong-Chan


    .... Information on patients older than 50 years, who sustained a subsequent hip fracture, were obtained from the records of eight Jeju Island hospitals between 2002 and 2011 to calculate the incidence...

  14. Incidence of fractures of the femur, including subtrochanteric, up to 8 years since initiation of oral bisphosphonate therapy

    Pazianas, M; Abrahamsen, B; Wang, Y;


    In a cohort study of users of bisphosphonates, we evaluated the incidence of fragility fractures at all sites on the femur following for up to 8 years of therapy with alendronate or risedronate. We did not find evidence for a reversal of fracture protection with long-term use of bisphosphonates. ...

  15. Declining incidence of hip fractures and the extent of use of anti-osteoporotic therapy in Denmark 1997-2006

    Abrahamsen, B; Vestergaard, P


    The incidence of hip fractures in Denmark declined by about 20% from 1997 to 2006 in both men and women aged 60 and over. The decrease in hip fracture rates was much too large to be explained by the extent of anti-osteoporotic medication used in the country....

  16. Potential Explanatory Factors for Higher Incident Hip Fracture Risk in Older Diabetic Adults

    Elsa S. Strotmeyer


    Full Text Available Type 2 diabetes is associated with higher fracture risk. Diabetes-related conditions may account for this risk. Cardiovascular Health Study participants (N=5641; 42.0% men; 15.5% black; 72.8±5.6 years were followed 10.9 ± 4.6 years. Diabetes was defined as hypoglycemic medication use or fasting glucose (FG ≥126 mg/dL. Peripheral artery disease (PAD was defined as ankle-arm index <0.9. Incident hip fractures were from medical records. Crude hip fracture rates (/1000 person-years were higher for diabetic vs. non-diabetic participants with BMI <25 (13.6, 95% CI: 8.9–20.2 versus 11.4, 95% CI: 10.1–12.9 and BMI ≥25 to <30 (8.3, 95% CI: 5.7–11.9 versus 6.6, 95% CI: 5.6–7.7, but similar for BMI ≥30. Adjusting for BMI, sex, race, and age, diabetes was related to fractures (HR = 1.34; 95% CI: 1.01–1.78. PAD (HR = 1.25 (95% CI: 0.92–1.57 and longer walk time (HR = 1.07 (95% CI: 1.04–1.10 modified the fracture risk in diabetes (HR = 1.17 (95% CI: 0.87–1.57. Diabetes was associated with higher hip fracture risk after adjusting for BMI though this association was modified by diabetes-related conditions.

  17. Post-mortem imaging of laryngohyoid fractures in strangulation incidents: first results.

    Kempter, M; Ross, S; Spendlove, D; Flach, P M; Preiss, U; Thali, M J; Bolliger, S A


    Fractures and soft-tissue injuries of the neck are of great importance in forensic pathology, as they help in assessing whether strangulation took place, and if so, how severely. In this study, we examined the usefulness of post-mortem imaging with multislice computed tomography (MSCT) in detecting lesions of the laryngohyoid structures and the surrounding soft-tissues. For this purpose, we examined MSCT images of the neck of eight deceased persons who had suffered different types of strangulation and compared the findings with those obtained at the subsequent forensic autopsy. In six of the eight cases (75%), the fracture findings at autopsy were concordant with those found with MSCT. In the two non-congruent cases, MSCT revealed fractures, which were not discovered at autopsy. Soft-tissue haemorrhages were detected by autopsy in five cases, but only in one case with MSCT. MSCT does not suffice in detecting soft-tissue injuries. These preliminary results are promising regarding the detection of fractures in strangulation cases. If these results can be confirmed in larger studies, we believe that post-mortem MSCT may serve - in combination with a thorough external examination and a profound incident-scene investigation - as a useful decision-making tool regarding the necessity of further examinations, i.e. autopsy.

  18. Lower limb stress fractures in sport: Optimising their management and outcome

    Robertson, Greg A J; Wood, Alexander M


    Stress fractures in sport are becoming increasing more common, comprising up to 10% of all of sporting injuries. Around 90% of such injuries are located in the lower limb. This articles aims to define the optimal management of lower limb stress fractures in the athlete, with a view to maximise return rates and minimise return times to sport. Treatment planning of this condition is specific to the location of the injury. However, there remains a clear division of stress fractures by “high” and “low” risk. “Low risk” stress fractures are those with a low probability of fracture propagation, delayed union, or non-union, and so can be managed reliably with rest and exercise limitation. These include stress fractures of the Postero-Medial Tibial Diaphysis, Metatarsal Shafts, Distal Fibula, Medial Femoral Neck, Femoral Shaft and Calcaneus. “High risk” stress fractures, in contrast, have increased rates of fracture propagation, displacement, delayed and non-union, and so require immediate cessation of activity, with orthopaedic referral, to assess the need for surgical intervention. These include stress fractures of the Anterior Tibial Diaphysis, Fifth Metatarsal Base, Medial Malleolus, Lateral Femoral Neck, Tarsal Navicular and Great Toe Sesamoids. In order to establish the optimal methods for managing these injuries, we present and review the current evidence which guides the treatment of stress fractures in athletes. From this, we note an increased role for surgical management of certain high risk stress fractures to improve return times and rates to sport. Following this, key recommendations are provided for the management of the common stress fracture types seen in the athlete. Five case reports are also presented to illustrate the application of sport-focussed lower limb stress fracture treatment in the clinical setting. PMID:28361017

  19. Stress fractures of ankle and wrist in childhood: nature and frequency

    Oestreich, Alan E. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Bhojwani, Nicholas [University of Cincinnati College of Medicine, Cincinnati, OH (United States)


    Stress fractures of many etiologies are found not infrequently in various tarsal bones but are less commonly recognized in carpal bones. To assess the distribution of tarsal and carpal stress fractures. During the last three decades, the senior author collected locations of tarsal and carpal bone stress fracture callus seen on plain radiographs. 527 children with tarsal and carpal stress fractures were identified (88 children had multiple bones involved). The totals were: calcaneus 244, cuboid 188, talus 121, navicular 24, cuneiforms 23, capitate 18, lunate 1, and scaphoid 1. Stress fractures were more frequently seen once we became aware each particular bone could be involved. Tarsal and carpal stress fractures in children are not rare. Careful perusal of these bones is urged in all susceptible children with limping or wrist pain. (orig.)

  20. Pace bowlers in cricket with history of lumbar stress fracture have increased risk of lower limb muscle strains, particularly calf strains

    John Orchard


    Full Text Available John Orchard1, Patrick Farhart2, Alex Kountouris3, Trefor James3, Marc Portus31School of Public Health, University of Sydney, Australia; 2Punjab Kings XI team, Indian Premier League, India; 3Cricket Australia, Melbourne, AustraliaObjective: To assess whether a history of lumbar stress fracture in pace bowlers in cricket is a risk factor for lower limb muscle strains.Methods: This was a prospective cohort risk factor study, conducted using injury data from contracted first class pace bowlers in Australia during seasons 1998–1999 to 2008–2009 inclusive. There were 205 pace bowlers, 33 of whom suffered a lumbar stress fracture when playing first class cricket. Risk ratios ([RR] with 95% confidence intervals[CI] were calculated to compare the seasonal incidence of various injuries between bowlers with a prior history of lumbar stress fracture and those with no history of lumbar stress fracture.Results: Risk of calf strain was strongly associated with prior lumbar stress fracture injury history (RR = 4.1; 95% CI: 2.4–7.1. Risks of both hamstring strain (RR = 1.5; 95% CI: 1.03–2.1 and quadriceps strain (RR = 2.0; 95% CI: 1.1–3.5 were somewhat associated with history of lumbar stress fracture. Risk of groin strain was not associated with history of lumbar stress fracture (RR = 0.7; 95% CI: 0.4–1.1. Other injuries showed little association with prior lumbar stress fracture, although knee cartilage injuries were more likely in the non-stress fracture group.Conclusion: Bony hypertrophy associated with lumbar stress fracture healing may lead to subsequent lumbar nerve root impingement, making lower limb muscle strains more likely to occur. Confounders may be responsible for some of the findings. In particular, bowling speed is likely to be independently correlated with risk of lumbar stress fracture and risk of muscle strain. However, as the relationship between lumbar stress fracture history and calf strain was very strong, and that there is a

  1. Radiographic factors and effect of fifth metatarsal Jones and diaphyseal stress fractures on participation in the NFL.

    Carreira, Dominic S; Sandilands, Scott M


    Jones fracture and proximal diaphyseal stress fracture of the fifth metatarsal have been associated with prolonged healing times and nonunions. We hypothesized that the Jones fracture and proximal diaphyseal stress fracture have a high incidence in elite collegiate football players and that they lead to a decrease in participation in the NFL. Also, we hypothesized that these fractures are associated with a cavovarus foot alignment. The database collected by a single NFL team during the 2004 to 2009 NFL Combines was reviewed to identify players with Jones and proximal diaphyseal fifth metatarsal fractures. A total of 74 fifth metatarsal fractures were identified in 68 players. Subsequent participation data also were collected through the website and included games played and years played. Digital plain radiographs and additional imaging studies also were reviewed to determine the extent of healing, types of fixation utilized, and foot alignment. The locations of fractures in the proximal fifth metatarsal were 45 (61%) in the Jones area, 15 (20%) in the proximal diaphyseal area, and 14 (19%) of indeterminate location. The number of patients treated with intramedullary fixation was 55/74 (74%). Of 74 proximal fifth metatarsal fractures, 9 (12.2%) were nonunions at the time of the NFL Combine medical examinations. With the numbers available, the average number of games played in the NFL was not significantly different in the fifth metatarsal fracture group, 16.9, compared to the control group, 24.9 (P > .05). The average number of games started was 7.4 in the fracture group versus 12.1 in the control group (P > .05). No significant differences were noted in the number of years played in the NFL. Except for talonavicular angle measurements, all measurements of coronal plane alignment demonstrated significant differences across groups, but no differences were noted in sagittal plane alignment. No statistically significant difference was noted in participation in

  2. Association of Respiratory Tuberculosis with Incident Bone Fracture: Bridging the Tuberculosis Airway Infection and the Osteoporotic Bone

    Yeh, Jun-Jun; Wang, Yu-Chiao; Lin, Che-Chen; Lin, Cheng-Li; Hsu, Wu-Huei


    Objective The relationship between respiratory tuberculosis (RT) and incident fragility fracture and osteoporosis/fragility fracture in the general population is not well determined; therefore, we conducted a nationwide cohort study to investigate this relationship. Methods We used the National Health Insurance Research Database of Taiwan to identify 6612 newly diagnosed patients with RT (RT cohort) and 13220 patients without RT (non-RT cohort) from 1999 to 2005. The mean durations of follow-up were (6.73 ± 4.00 years, 8.11 ± 3.24 years) in the (RT cohort, non- RT cohort); respectively. The occurrence of incident fragility fracture and osteoporosis/fragility fracture were followed up until the end of 2011. The adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) and 98% CIs of incident fragility fracture and osteoporosis/fragility fracture were estimated using the multivariable Cox proportional hazard model after adjusting for age, sex, occupation, drug use, and comorbidities. Results A Cox proportional hazards regression analysis was performed and showed the aHRs of [incident fragility fracture; osteoporosis/fragility fracture] were [1.69 (95% CI = 1.26–2.28, 98% CI = 1.18–2.44); 1.42 (95% CI = 1.25–1.61, 98% CI = 1.21–1.65)] between the RT and non-RT cohorts. Regarding the sex, the aHRs of the [incident fragility fracture; osteoporosis / fragility fracture] were [1.57 (98% CI = 1.10–2.23, 98% CI = 1.02–2.41); 1.15 (95% CI = 0.97–1.36, 98% CI = 0.94–1.41)] in the men. The aHRs of the RT cohort without oral steroid use in the [incident fragility fracture; osteoporosis / fragility fracture] were [1.87 (95% CI = 1.20–2.90, 98% CI = 1.09–3.19); 1.41 (95% CI = 1.19–1.67, 98% CI = 1.14–1.74)]. Conclusion The RT associated with the incident fragility fracture, either in men or absence of oral steroid use. PMID:28005963

  3. Association of serum fibroblast growth factor 23 (FGF23) and incident fractures in older men: the Osteoporotic Fractures in Men (MrOS) study.

    Lane, Nancy E; Parimi, Neeta; Corr, Maripat; Yao, Wei; Cauley, Jane A; Nielson, Carrie M; Ix, Joseph H; Kado, Deborah; Orwoll, Eric


    Normal mineral metabolism is critical for skeletal integrity, and recently serum fibroblast growth factor 23 (FGF23) levels were found to be directly related to overall fracture risk in elderly Swedish men. To confirm this association, we performed a prospective case-cohort study to understand the relation of FGF23 and fracture risk in older white men enrolled in the Osteoporotic Fractures in Men (MrOS) study. In the cohort of 5994 men attending the baseline MrOS examination, we evaluated a subgroup of 387 men with incident nonvertebral fracture including 73 hip fractures and a sample of 1385 men randomly selected from the cohort with baseline mineral and calcium hormone measurements. FGF23 was measured in baseline serum samples by ELISA (Millipore, Billerica, MA, USA). Modified Cox proportional hazards models that account for case-cohort study design were used to estimate the relative hazards (RH) of fracture in men across quartiles of FGF23. Subjects were also stratified by renal function, and RH per strata was estimated in men with the highest quartile of FGF23 compared with quartiles 3, 2, and 1. Overall, there was no difference in risk of nonspine or hip fracture by baseline FGF23. However, associations differed by strata of eGFRCrCy . Among men with eGFRCrCys 60 mL/min/1.73 m2 (304/1370 fractures) the RH was 0.91 (95% CI 0.66-1.25) after adjustment for age, clinic site, body mass index, race, total hip bone mineral density, vitamin D, parathyroid hormone, alcohol use, physical activity, fracture history, and serum phosphorus. Serum FGF23 levels are not associated with incident fractures in elderly men overall. However, higher levels of serum FGF23 are associated with fracture risk in those with poor renal function.

  4. Visual impairment and the incidence of falls and fractures among older people: longitudinal findings from the Blue Mountains Eye Study.

    Hong, Thomas; Mitchell, Paul; Burlutsky, George; Samarawickrama, Chameen; Wang, Jie Jin


    We assessed the impact of visual impairment on the incidence of falls and fractures in older persons. Of 3654 baseline participants, 2334, 1952, and 1149 were re-examined after 5, 10, and 15 years. Presenting visual acuity (VA) was measured at each examination. Bilateral and unilateral visual impairment was defined as VA worse than 20/40 in the better and worse eye, respectively. Incident visual impairment was defined in eyes with VA 20/40 or better at baseline, which subsequently developed visual impairment. Incidence of falls was assessed over the 12 months before each visit, whereas incidence of fractures was assessed over the 5 years between two visits. Discrete logistic-regression models with time-dependent variables were used to assess associations between visual impairment and subsequent falls and fractures after adjusting for potential confounding variables. The proportions of participants reporting ≥2 falls ranged between 10% and 14%, and proportions reporting fractures ranged between 12% and 21%, across the three follow-up visits. Participants with incident visual impairment were more likely to report ≥2 falls in 5 years, OR (odds ratio) 1.46, 95% confidence interval (CI) 1.04 to 2.04 (bilateral), and OR 1.22, 95% CI 0.98 to 1.51 (unilateral). Compared to participants with normal vision, those with incident unilateral visual impairment had a higher incidence of fractures over 5 years (OR, 1.27; 95% CI, 0.98-1.51). No increased incidence of falls or fractures was evident after 5+ years among participants with visual impairment. In this older cohort, recent development of visual impairment was associated with increased likelihood of subsequent falls and fractures in the next 5 years, independent of other confounding variables. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

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

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


    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. 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. 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. The rap stress stimulator significantly shortened the fracture healing time and reduced the rate of nonunion for treating open tibia and fibula fractures.

  6. In-situ stress from hydraulic fracture measurements in G Tunnel, Nevada Test Site

    Smith, C.; Vollendorf, W. C.; Warren, W. E.


    Hydraulic fracture work in G Tunnel, Nevada Test Site, performed to obtain the in-situ stress state is discussed. Field equipment and procedures are described; analysis is developed to relate the hydraulic fracture pressures to the in-situ stress state. Pressure data are analyzed to provide estimates of the stress state at a number of locations in the tunnel complex. A unique feature of the work is the mineback - a mining process in which the rock is cut away to reveal the actual plane of the fracture. Advantages, limitations, and problem areas associated with extracting in-situ stress fields from hydraulic fracture pressure records are discussed in detail.

  7. Incidencia de fracturas mandibulares en Guyana INCIDENCE OF MANDIBULAR FRACTURES IN GUYANA

    Luis Hernández Pedroso


    Full Text Available Se realiza un estudio retrospectivo de la incidencia de las fracturas mandibulares en relación con el total de las fracturas maxilofaciales atendidas en la República de Guyana durante el año 2001 debido a su alta presentación en nuestro quehacer diario, con el objetivo de determinar el comportamiento de estas lesiones y su relación con la edad, sexo, etiología y área mandibular vulnerable. Las variables estudiadas fueron sexo, edad, causa de la fractura y región afectada. Las fracturas mandibulares ocuparon el 56,6 % del total de fracturas maxilofaciales y fue más frecuente en los hombres ( 89,5 %. Los grupos etáreos de mayor incidencia fueron de 25 a 34 y de 35 a 44 años, con el 30,6 %. La causa más común de fracturas mandibulares fue la agresión personal ( 68,6 % y la región anatómica más afectada el ángulo mandibular ( 67,4 %.A retrospective study of the incidence of mandibular fractures in relation to the total of maxillofacial fractures attended in the Republic of Guyana during 2001 was conducted taking into account its high ocurrence in our daily practice in order to determine the behavior of these injuries and its connection with age, sex, etiology and vulnerable mandibular area. The variables studied were sex, age, cause of the fracture and affected region. The mandibular fractures accounted for 56.6 % of the total of maxillofacial fractures and they were more frequent in men (89.5 %. The age groups with the highest incidence were from 25 to 34 and from 35 to 44 years old, accounting for 30.6 %. The most frequent cause of mandibular fracture was personal aggression (68.6 % and the commonest anatomical region was the mandibular angle (67.4 %.

  8. Critical incident stress debriefing: clinical applications and new directions.

    Miller, L


    Critical Incident Stress Debriefing (CISD) was originally developed as a short-term, group-format, preventive mental health intervention for traumatized law enforcement and emergency services personnel. The debriefing model has since been applied to a variety of clinical groups and crisis situations, correspondingly undergoing modifications in its structure and process. This review describes the CISD approach and explores some of the new directions being taken by practitioners of this intervention strategy. In addition, this review addresses some of the recent critiques of the CISD model, and makes recommendations for optimal utilization of this clinical tool with those populations most likely to benefit from it.

  9. Critical incident stress debriefing after adverse patient safety events.

    Harrison, Reema; Wu, Albert


    Adverse events (AEs) are common, estimated to occur in around 10% internationally. Although preventable harm can be minimized, when AEs occur it is important that they be managed appropriately. AEs can be traumatic not only for patients, their friends, and relatives, but also for the involved clinicians, who have been referred to as "second victims" in a growing body of international research. Despite the frequency with which AEs occur, organizational mechanisms for supporting staff in these circumstances are not routinely embedded in healthcare settings. Critical Incident Stress Debriefing (CISD) has long been provided for professionals, such as disaster workers, who are exposed to traumatic and high-stress events. CISD is considered an effective strategy to promote resilience and recovery. We explore the potential value of providing CISD for health professionals involved in patient safety-related AEs and discuss the instances in which this could be routinely implemented.

  10. Humeral cortical thickness in female Bantu - its relationship to the incidence of femoral neck fracture

    Bloom, R.A.; Pogrund, H.


    Measurements of the humeral cortical thickness demonstrate that generalised osteoporosis in female Bantu commences in the fifth decade and gradually increases until, in the ninth decade, all subjects are osteoporotic. The combined cortical thickness (CCT) of the humerus in young adults is very similar to that found previously in a white London population and the loss of cortex with age is very similar. It is concluded that the known low incidence of femoral neck fracture in Bantu is not due to a lower incidence of generalised osteoporosis but to environmental factors. The chief environmental factor postulated is the greater amount of physical work performed by the Bantu. A more careful mode of walking is suggested as a subsidiary cause.

  11. Experimental study of the stress effect on attenuation of normally incident P-wave through coal

    Feng, Junjun; Wang, Enyuan; Chen, Liang; Li, Xuelong; Xu, Zhaoyong; Li, Guoai


    The purpose of this study is to experimentally investigate the stress effect on normally incident P-wave attenuation through coal specimens. Laboratory tests were carried out using a Split Hopkinson pressure bar (SHPB) system, and a modified method was proposed to determine the quality factor (Q) of P-waves through coal specimens. Larger quality factor denotes less energy attenuated during P-wave propagating through coal. Experimental results indicate that the quality factor and stress (σ) within coal specimens are positively correlated. The P-wave propagation through coal specimens causes crack closure at the beginning of the coal fracture process in SHPB tests, an innovative model was thus proposed to describe the relationship between the crack closure length and the dynamic stress induced by P-wave. Finally, the stress effect on P-wave attenuation through coal was quantitatively represented by a power function Q = a(c-bσ)- 6, and the material constants a, b, and c were determined as 1.227, 1.314, and 0.005, respectively. The results obtained in this study would be helpful for engineers to estimate seismic energy attenuation and coal mass instability in coal mines.

  12. Prevalence, incidence and etiology of hyponatremia in elderly patients with fragility fractures.

    Kirsten Cumming

    Full Text Available INTRODUCTION: Hyponatremia (serum sodium<135 mMol/L is the commonest electrolyte imbalance encountered in clinical practice. It is associated with multiple poor clinical outcomes including increased mortality, longer hospital stay, falls and fractures. Prevalence is higher in frail patient groups, and elderly patients with fragility fractures (EPFF are particularly susceptible. Euvolemic hyponatremia due to syndrome of inappropriate anti-diuretic hormone (SIADH is widely assumed to be the commonest cause. However, little is known about the epidemiology and etiology of hyponatremia in EPFF. This study established prevalence, incidence and etiology of hyponatremia in EPFF. METHODS: Prospective observational study of consenting adults aged ≥65 years admitted with a fragility fracture to a university hospital between 7th January and 4th April 2013. Prevalence of hyponatremia on admission and incidence of cases developing in hospital were reported. Etiology of cases of hyponatremia was determined by consensus of an expert panel using pre-specified data collected daily. RESULTS: 127/212 (60% EPFF were recruited (mean age 79 yrs, 78% female. Two participants withdrew mid-study. Of those not recruited, 66 had incapacity to consent and 19 refused participation. Point prevalence of hyponatremia on admission was 13.4% and a further 12.6% developed hyponatremia during admission. Hypovolemic hyponatremia was predominant (70%. 73% of cases were multi-factorial in etiology. The commonest potentially causative factors in cases of hyponatremia were thiazide diuretics (76%, dehydration (70%, proton pump inhibitors (70%, SIADH (27% and mirtazapine (15%. CONCLUSION: Hyponatremia is highly prevalent in EPFF, seen in 26% of cases. Dehydration and prescription of thiazide diuretics and proton pump inhibitors were the commonest potentially causative factors, not SIADH.

  13. Sacral Stress Fracture Mimicking Lumbar Radiculopathy in a Mounted Police Officer: Case Report and Literature Review.

    Bednar, Drew A; Almansoori, Khaled


    Study Design Case report and review of the literature. Objective To present a unique case of L5 radiculopathy caused by a sacral stress fracture without neurologic compression. Methods We present our case and its clinical evolution and review the available literature on similar pathologies. Results Relief of the unusual mechanical loading causing sacral stress fracture led to rapid resolution of radiculopathy. Conclusion L5 radiculopathy can be caused by a sacral stress fracture and can be relieved by simple mechanical treatment of the fracture.


    Hiroyuki Fujioka


    Full Text Available A 17-year-old boy, who played a weight lifting in high school, sustained stress fracture of the first rib without any causes. We successfully treated first rib stress fracture with limitation of using the upper extremity and with using low-intensity pulsed ultrasound

  15. Stress fractures of forearm bones in military recruits of rifle drill training.

    Kuo, Chun-Lin; Pan, Ru-Yu; Wu, Jia-Lin; Huang, Wen-Sheng; Wang, Shyu-Jye


    Stress fractures rarely occur in the forearms. These injuries usually occur in healthy young patients, which are usually neglected by patients or physicians. Early diagnosis and treatment are important to avoid late complications of these fractures. The purpose of this study was to analyze a case series of military recruits who participated in rifle drill training and presented with forearm stress fractures at our institution. We evaluated 216 military recruits of rifle drill training. Twelve patients were diagnosed with forearm stress fractures by typical history, physical examination, laboratory studies, serial radiographs, and bone scan examinations. Eighteen fractures were found in 12 patients. On initial radiographs, 11 had periosteal reactions, 4 had callus formation with complete fracture lines, and 3 were normal. All 18 fractures had increase radioactivity in the involved middle (15 of 18) or distal (2 of 18) ulnae and one middle radius (1 of 18). Stress fractures of the forearms in military rifle drill training usually occur in middle ulnae. Fifty percent of them were bilateral fractures. A high index of suspicion is the key to diagnosis. Early diagnosis with conservative treatment can achieve satisfactory results and avoid late complications of stress fractures.

  16. The World Trade Center Attack: Helping the helpers: the role of critical incident stress management

    Hammond, Jeffrey; Brooks, Jill


    Healthcare and prehospital workers involved in disaster response are susceptible to a variety of stress-related psychological and physical sequelae. Critical incident stress management, of which critical incident stress debriefing is a component, can mitigate the response to these stressors. Critical incident stress debriefing is a peer-driven, therapist-guided, structured, group intervention designed to accelerate the recovery of personnel. The attack on the World Trade Center, and the impac...

  17. Acute Stress Fracture of the Pelvis after Total Hip Arthroplasty: A Case Report.

    Akinbo, Oluwaseun; Tyagi, Vineet


    Acute hip pain following total hip arthroplasty (THA) could have numerous causes to include stress fracture of the pelvis. Stress fractures of the pelvis are rare and have been reported to involve the medial wall and the pubic ramus. A unique case is presented demonstrating the clinical presentation and management of an acute stress fracture of ilium and anterior column following a THA. A 72-year-old man underwent an uncomplicated right THA. He was noted to have femoral head resorption and thin osteoporotic bone intraoperatively. He initially did well postoperatively and ambulating without pain or assistive devices. Within 1 month of surgery, he returned with acute right hip pain without any traumatic event. Radiographs showed migration of the acetabular component and computed tomography scan confirmed a fracture through the ilium. The patient underwent revision surgery, where the fracture was reduced and internal fixation was achieved with a reconstruction plate and acetabular cage construct. At 9 months postoperatively, the patient remained pain-free with full weight bearing and with stable radiographs. Elderly patients who undergo THA may have low bone mineral density. These patients can develop stress fractures in their pelvis after surgery. These fractures may involve the medial wall, posterior column, or posterior wall. In patients who develop atraumatic pain postoperatively, it is important to consider for potential stress fractures of the ilium and evaluate appropriately with imaging. In these cases, revision surgery can be necessary to provide fixation of the stress fracture.

  18. Exercise-induced rib stress fractures: influence of reduced bone mineral density

    Vinther, Anders; Kanstrup, Inge-Lis; Christiansen, Erik;


    Exercise-induced rib stress fractures have been reported frequently in elite rowers during the past decade. The etiology of rib stress fractures is unclear, but low bone mineral density (BMD) has been suggested to be a potential risk factor for stress fractures in weight-bearing bones. The present...... study investigated BMD in seven Danish national team rowers with previous rib stress fracture (RSF) and 7 controls (C) matched for gender, age, height, weight and training experience. Total body scan and specific scans of the lumbar spine (L2-L4), femoral neck and distal radius were performed using...... density may be a potential risk factor for the development of exercise-induced rib stress fractures in elite rowers....

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

    Kahanov L


    Full Text Available Leamor Kahanov,1 Lindsey E Eberman,2 Kenneth E Games,2 Mitch Wasik2 1College of Health Science, Misericordia University, Dallas, PA, USA; 2Department of Applied Medicine and Rehabilitation, Indiana State University, Terre Haute, IN, USA Abstract: 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. Keywords: medial tibial stress syndrome, stress injury, nonunion stress fracture

  20. Creep and Fracture of a Protein Gel under Stress

    Leocmach, Mathieu; Perge, Christophe; Divoux, Thibaut; Manneville, Sébastien


    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 protein gel is reminiscent of brittle solids: after a primary creep regime characterized by a power-law behavior whose 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, brittlelike soft solids.

  1. The World Trade Center Attack: Helping the helpers: the role of critical incident stress management

    Hammond, Jeffrey; Brooks, Jill


    Healthcare and prehospital workers involved in disaster response are susceptible to a variety of stress-related psychological and physical sequelae. Critical incident stress management, of which critical incident stress debriefing is a component, can mitigate the response to these stressors. Critical incident stress debriefing is a peer-driven, therapist-guided, structured, group intervention designed to accelerate the recovery of personnel. The attack on the World Trade Center, and the impact it may have on rescue, prehospital, and healthcare workers, should urge us to incorporate critical incident stress management into disaster management plans. PMID:11737916

  2. The World Trade Center attack. Helping the helpers: the role of critical incident stress management.

    Hammond, J; Brooks, J


    Healthcare and prehospital workers involved in disaster response are susceptible to a variety of stress-related psychological and physical sequelae. Critical incident stress management, of which critical incident stress debriefing is a component, can mitigate the response to these stressors. Critical incident stress debriefing is a peer-driven, therapist-guided, structured, group intervention designed to accelerate the recovery of personnel. The attack on the World Trade Center, and the impact it may have on rescue, prehospital, and healthcare workers, should urge us to incorporate critical incident stress management into disaster management plans.

  3. Evolution of stress and seismicity in fractured geothermal reservoirs

    Schoenball, Martin


    Heat Mining, Soultz, forms the basis of the studies. The PhD project was conducted partly within the FP7 GEISER (Geothermal Engineering Integrating Mitigation of Induced Seismicity in Reservoirs) project, funded by the European Commission and it benefited largely from fruitful collaborations with Universite de Strasbourg, Geowatt AG, Zuerich, GFZ German Research Centre for Geosciences, Potsdam and CSIRO Earth Science and Resources Engineering, Perth. In the first study, I analyze whether interaction of seismicity by static stress transfer plays a significant role on the spatio-temporal evolution of seismicity. I follow an analytical approach to compute the displacement field of a rectangular earthquake source. Through stacking of several sources, realistic slip distributions are obtained. The analysis reveals seemingly random distributed patches of stress increase and stress decrease of less than ± 1 MPa, except for very localized areas. Since the fracture planes have varying orientations, they form a volumetric fracture network. About 60% of hypocenters are found in areas with increased Coulomb stress where their potential for failure was increased by static stress transfer. A different behavior is observed for slippage of neighboring asperities on larger fault zones. Here, failure of asperities leads to a direct stress increase in adjacent asperities, which are then more likely to fail. This is exemplified on a cluster of events occurring on the largest fault zone in Soultz, after shut-in of the well GPK2. Subsequently, the peculiar behavior of seismicity and the hydraulic regime following shut-in of the well GPK2 is highlighted and investigated by further analysis of focal mechanism solutions. An increase of the thrust faulting component following shut-in is observed. The changes of the stress field are derived from spatio-temporally resolved inversions of focal mechanism solutions. A very strong reduction of the maximum horizontal stress and an increase of the

  4. Measuring Stress-dependent Fluid Flow Behavior in Fractured Porous Media

    Huo, Da; Benson, Sally


    Maintaining long-term storage of CO2 is one of the most important factors for selecting the site for a geological CO2 storage project. Nevertheless, it is important to be prepared for possible leakage due to leaking wells or leakage pathways through the seal of a storage reservoir. This research project is motivated by the need to understand unexpected CO2 leakage. The goal of this research is to investigate stress-dependent fracture permeability and relative permeability of CO2/brine systems. Laboratory measurements of fracture permeability and fracture apertures have been made as a function of effective stress. The phenomenon that permeability decreases with effective pressure increase is observed. Due to deformation of the fracture surface during periods with high effective stress, hysteretic behavior of fractured rock permeability is also observed in core flood experiments. A series of experiments are conducted to investigate permeability hysteresis. A single saw-cut fracture is created in the rock sample to simplify the problem and to focus on the fracture itself. Permeability is measured using a high pressure core flood apparatus with X-Ray CT scanning to measure the fracture aperture distributions. Two permeability data sets, including a high permeability fractured Berea Sandstone and a low permeability fractured Israeli Zenifim Formation sandstone, show clear hysteretic behavior in both permeability and fracture aperture in repeated cycles of compression and decompression. Due to closure of the fracture aperture, when a fractured rock is compressed axially, the permeability has an exponential decline with effective pressure, as expected from stress-dependent permeability theory. When the fractured rock is decompressed afterwards, permeability increases, but not along the compression pathway and never returns to the original value. Depending on the nature of the fracture and host rock, permeability can decrease from a factor of 2 to 40. After one or more

  5. Review of possible correlations between in situ stress and PFL fracture transmissivity data at Forsmark

    Martin, Derek (University of Alberta (United States)); Follin, Sven (SF GeoLogic AB (Sweden))


    In laboratory samples, the fracture transmissivity decreases significantly as the confining stress increases. While these experimental relationships are widely accepted and validated on laboratory samples, it is unknown if such relationships exist in situ or if these relationships can be scaled from the centimetre-scale laboratory tests to the metre-scale of in situ fractures. The purpose of this work is to assess the relationship between the structural-hydraulic data gathered in deep, cored boreholes at Forsmark and the in situ stress state acting on the these fractures. In conclusion, there does not appear to be sufficient evidence from these analyses to support the notion that the magnitude of the flow along the fractures at Forsmark is solely controlled by the in situ stress acting on the fracture. This should not be surprising because the majority of the fractures formed more than 1 billion years ago and the current in situ stress state has only been active for the past 12 million years. It is more likely that the transmissivity values are controlled by fracture roughness, open channels within the fracture, fracture stiffness and fracture infilling material

  6. Incidence of and risk factors for non-vertebral and vertebral fracture in female Chinese patients with systemic lupus erythematosus: a five-year cohort study.

    Zhu, T Y; Griffith, J F; Au, S-K; Tang, X-L; Kwok, A W; Leung, P-C; Li, E K; Tam, L-S


    The objective of this paper is to investigate the incidence of both non-vertebral and vertebral fracture in female patients with systemic lupus erythematosus (SLE) and to identify risk factors for incident fracture. In a five-year prospective study of 127 female Chinese SLE patients with an average age of 46.9 years (SD: 10.1 years), information on potential risk factors, including demographics, clinical data and bone mineral density (BMD) at lumbar spine and hip by dual-energy X-ray absorptiometry was collected at baseline. At follow-up, participants reported incident non-vertebral fracture during the study period. Semi-quantitative analysis was used to determine incident vertebral fracture on lateral thoracic and lumbar radiographs, defined as any vertebral body graded normal at baseline and at least mildly deformed (20%-25% reduction or more in any vertebral height) at follow-up. Nine incident non-vertebral fractures occurred in eight patients during the study period. Six patients had one or more incident vertebral fractures. The incidence of non-vertebral and vertebral fracture was 1.26 and 0.94 per 100 patient-years, respectively. In multivariate logistic analyses, independent variables associated with incident non-vertebral fracture were duration of glucocorticoid use and prevalent lumbar spine osteoporosis, while risk factors associated with incident vertebral fracture were higher organ damage and prevalent lumbar spine osteoporosis. The incidence of fracture in SLE patients is lower than the prevalence reported in cross-sectional studies. Lumbar spine BMD appears to have a stronger relationship with incident fracture than hip BMD. This warrants further investigation regarding the optimal site of BMD measurement when predicting fracture risk in SLE patients. © The Author(s) 2014 Reprints and permissions:

  7. Association of Increased Urinary Albumin With Risk of Incident Clinical Fracture and Rate of Hip Bone Loss: the Osteoporotic Fractures in Men Study.

    Fink, Howard A; Vo, Tien N; Langsetmo, Lisa; Barzilay, Joshua I; Cauley, Jane A; Schousboe, John T; Orwoll, Eric S; Canales, Muna T; Ishani, Areef; Lane, Nancy E; Ensrud, Kristine E


    Prior studies suggest that increased urine albumin is associated with a heightened fracture risk in women, but results in men are unclear. We used data from Osteoporotic Fractures in Men (MrOS), a prospective cohort study of community-dwelling men aged ≥65 years, to evaluate the association of increased urine albumin with subsequent fractures and annualized rate of hip bone loss. We calculated albumin/creatinine ratio (ACR) from urine collected at the 2003-2005 visit. Subsequent clinical fractures were ascertained from triannual questionnaires and centrally adjudicated by review of radiographic reports. Total hip BMD was measured by DXA at the 2003-2005 visit and again an average of 3.5 years later. We estimated risk of incident clinical fracture using Cox proportional hazards models, and annualized BMD change using ANCOVA. Of 2982 men with calculable ACR, 9.4% had ACR ≥30 mg/g (albuminuria) and 1.0% had ACR ≥300 mg/g (macroalbuminuria). During a mean of 8.7 years of follow-up, 20.0% of men had an incident clinical fracture. In multivariate-adjusted models, neither higher ACR quintile (p for trend 0.75) nor albuminuria (HR versus no albuminuria, 0.89; 95% CI, 0.65 to 1.20) was associated with increased risk of incident clinical fracture. Increased urine albumin had a borderline significant, multivariate-adjusted, positive association with rate of total hip bone loss when modeled in ACR quintiles (p = 0.06), but not when modeled as albuminuria versus no albuminuria. Macroalbuminuria was associated with a higher rate of annualized hip bone loss compared to no albuminuria (-1.8% more annualized loss than in men with ACR fracture associations. In these community-dwelling older men, we found no association between urine albumin levels and risk of incident clinical fracture, but found a borderline significant, positive association with rate of hip bone loss. © 2016 American Society for Bone and Mineral Research. © 2016 American Society for Bone and

  8. Non-linear hydrotectonic phenomena: Part I - fluid flow in open fractures under dynamical stress loading

    Archambeau, C.B. [Univ. of Colorado, Boulder, CO (United States)


    A fractured solid under stress loading (or unloading) can be viewed as behaving macroscopically as a medium with internal, hidden, degrees of freedom, wherein changes in fracture geometry (i.e. opening, closing and extension) and flow of fluid and gas within fractures will produce major changes in stresses and strains within the solid. Likewise, the flow process within fractures will be strongly coupled to deformation within the solid through boundary conditions on the fracture surfaces. The effects in the solid can, in part, be phenomenologically represented as inelastic or plastic processes in the macroscopic view. However, there are clearly phenomena associated with fracture growth and open fracture fluid flows that produce effects that can not be described using ordinary inelastic phenomenology. This is evident from the fact that a variety of energy release phenomena can occur, including seismic emissions of previously stored strain energy due to fracture growth, release of disolved gas from fluids in the fractures resulting in enhanced buoyancy and subsequent energetic flows of gas and fluids through the fracture system which can produce raid extension of old fractures and the creation of new ones. Additionally, the flows will be modulated by the opening and closing of fractures due to deformation in the solid, so that the flow process is strongly coupled to dynamical processes in the surrounding solid matrix, some of which are induced by the flow itself.

  9. Trauma-exposed firefighters: relationships among posttraumatic growth, posttraumatic stress, resource availability, coping and critical incident stress debriefing experience.

    Sattler, David N; Boyd, Bill; Kirsch, Julie


    This project examines protective factors associated with resilience/posttraumatic growth and risk factors associated with posttraumatic stress among firefighters exposed to critical incidents. The participants were 286 (257 men and 29 women) volunteer and paid firefighters in Whatcom County, Washington. Participants completed an anonymous survey asking about demographics, critical incident exposure, posttraumatic stress symptoms, posttraumatic growth, resource availability, coping, occupational stress and critical incident stress debriefing experience. Most participants had significant critical incident exposure, and about half had attended critical incident stress debriefing sessions. Posttraumatic growth was associated with being female, critical incident exposure, critical incident stress debriefing attendance, posttraumatic stress symptoms (negative association), occupational support, occupation satisfaction, occupational effort, problem-focused coping, emotion-focused coping and personal characteristic resources. Posttraumatic stress symptoms were positively associated with years of firefighting, burnout, occupational effort and disengagement coping and negatively associated with critical incident stress debriefing attendance, posttraumatic growth, social support, internal locus of control, personal characteristic resources, energy resources and condition resources. The findings support conservation of resources stress theory and show that the maintenance and acquisition of resources can offset losses and facilitate resilience/posttraumatic growth. Implications of the findings for enhancing firefighter resources, facilitating resilience and minimizing occupational stressors are discussed. © 2014 John Wiley & Sons, Ltd.

  10. The Provision of Critical Incident Stress Debriefing Services by EAPs: A Case Study.

    McWhirter, Ellen Hawley; Linzer, Marc


    Provides a description of critical incident stress debriefing (CISD) strategies used after a bank robbery-hostage incident. Intervention intended to reduce the effects of the incident on the employees' morale, health, and productivity. Knowledge of CISD procedures will enable counselors to respond effectively to traumatic incidents in the…

  11. Critical incident stress debriefing (CISD) in a shipping company.

    Saarni, H; Saari, S; Häkkinen, U


    Critical incident stress debriefing (CISD) is a method used successfully to reduce suffering from stress-related ailments such as insomnia, depression, anger, headaches etc. The resources of the shipping company are very limited and, thus, networking with existing organizations and specialists is necessary to carry out CISD effectively. The present company model has been adopted to take into account various situations and levels of disaster. The model has been adopted at three levels of events:Level 1. Serious accidents on shore, sudden deaths, severe events and threats. Events involving one or only few persons. Level 2. Life-threatening occupational accidents on board ship, suicide of a workmate, sudden death and fire on board ship. Events involving one person or limited group of persons. Level 3. Disasters at sea. Severe events involving all or nearly all persons on board ship. Actions at different levels: Level 1: A leaflet describing CISD, situations where it would be appropriate and where it is available, is given to each sailor. The victim is encouraged to seek CISD from public health care centres, most of which have their own services in Finland. Level 2. Training of about 8 hours is carried out by an experienced crisis psychologist for supervisors and officers on board ship. After the training they are able to identify stressful situations. At each harbour, the shipping company has made agreements with experienced crisis psychologists to act as specialists and contact persons on shore. These nominated psychologists will initiate CISD actions when necessary. If they need extra manpower they will turn to other psychologists. Level 3. In such serious accidents, the company's own resources alone are insufficient to provide effective CISD. All available public and private resources will he needed (health care organizations, Red Cross, Church etc.).

  12. Incidence and Predictors of Multiple Fractures Despite High Adherence to Oral Bisphosphonates

    Hawley, Samuel; Javaid, M Kassim; Rubin, Katrine H


    with high adherence. Fractures were considered after six months from treatment initiation and up to six months after discontinuation. Data from computerized records and pharmacy invoices were obtained from Sistema d'Informació per al Desenvolupament de l'Investigació en Atenció Primària (SIDIAP) (Catalonia...... predictors of ≥2 FWOT among patients having persisted with treatment ≥6months with overall medication possession ratio (MPR) ≥80%. Incidence of ≥2 FWOT was 2.4 (95% Confidence Interval (CI): 1.8-3.2) and 1.7 (95% CI: 1.2-2.2) per 1000 Person Years (PYs) within Catalonia and Denmark respectively. Older age...... of ≥2 FWOT identified within only one cohort were dementia, SHR = 4.46 (95% CI: 1.02-19.4) (SIDIAP) and history of recent or older fracture, SHR = 3.40 (95% CI: 1.50-7.68) and SHR = 2.08 (95% CI: 1.04-4.15) respectively (Denmark). Even among highly adherent users of oral BP therapy, a minority sustain...

  13. Dry fracture method for simultaneous measurement of in-situ stress state and material properties

    Serata, S. [Serata Geomechanics, Inc., Richmond, CA (United States); Oka, S.; Kikuchi, S. [JDC Corp., Tokyo (Japan)


    Based on the dry fracture principle, a computerized borehole probe has been developed to measure stress state and material properties, simultaneously. The probe is designed to obtain a series of measurements in a continuing sequence along a borehole length, without any interruptive measures, such as resetting packers, taking indentation of borehole wall, overcoming, etc. The new dry fracture probe for the single fracture method is designed to overcome the difficulties posed by its ancestor which was based on the double fracture method. The accuracy of the single fracture method is confirmed by a close agreement with the theory, FE modeling and laboratory testing.

  14. Radiological findings and healing patterns of incomplete stress fractures of the pars interarticularis

    Dunn, Andrew J.; Campbell, Robert S.D. [Royal Liverpool and Broadgreen University Teaching Hospitals, Department of Medical Imaging, Liverpool (United Kingdom); Mayor, Peter E. [Leighton Hospital, Department of Medical Imaging, Crewe, Cheshire (United Kingdom); Rees, Dai [Robert Jones and Agnes-Hunt Orthopaedic Hospital, Department of Orthopaedic Surgery, Oswestry, Shropshire (United Kingdom)


    The objective was to retrospectively record the CT and MRI features and healing patterns of acute, incomplete stress fractures of the pars interarticularis. The CT scans of 156 adolescents referred with suspected pars interarticularis stress fractures were reviewed. Patients with incomplete (grade 2) pars fractures were included in the study. Fractures were assessed on CT according to vertebral level, location of cortical involvement and direction of fracture propagation. MRI was also performed in 72 of the 156 cases. MRI images of incomplete fractures were assessed for the presence of marrow oedema and cortical integrity. Fracture healing patterns were characterised on follow-up CT imaging. Twenty-five incomplete fractures were identified in 23 patients on CT. All fractures involved the inferior or infero-medial cortex of the pars and propagated superiorly or superolaterally. Ninety-two percent of incomplete fractures demonstrated either complete or partial healing on follow-up imaging. Two (8%) cases progressed to complete fractures. Thirteen incomplete fractures in 11 patients confirmed on CT also had MRI, and 92% demonstrated oedema in the pars. Ten out of thirteen fractures (77%) showed a break in the infero-medial cortex with intact supero-lateral cortex, which correlated with the CT findings. MRI incorrectly graded one case as a complete (grade 3) fracture, and 2 cases as (grade 1) stress reaction. Six fractures had follow-up MRI, 67% showed partial or complete cortical healing, and the same number showed persistent marrow oedema. Incomplete fracture of the pars interarticularis represents a stage of the evolution of a complete stress fracture. The direction of fracture propagation is consistent, and complete healing can be achieved in most cases with appropriate clinical management. CT best demonstrates fracture size and extent, and is the most appropriate modality for follow-up. MRI is limited in its ability to fully depict the cortical integrity of

  15. Atypical bisphosphonate-associated subtrochanteric and femoral shaft stress fractures: diagnostic features on bone scan.

    Probst, Stephan; Rakheja, Rajan; Stern, Jerry


    A 69-year-old woman presented with a spontaneous right subtrochanteric hip fracture. Pan-imaging following orthopedic repair failed to identify a primary malignancy to explain the presumed pathologic basis for this fracture. The patient then underwent bone scintigraphy and SPECT/CT which showed mild uptake in multifocal endosteal thickening of the lateral left femoral diaphysis, diagnostic of bisphosphonate-associated femoral shaft stress fractures, but no evidence of metastatic bone disease. Atypical bisphosphonate-associated subtrochanteric and femoral shaft stress fractures have a fairly specific appearance on bone scintigraphy, and nuclear medicine physicians should be aware of this relatively infrequent emerging pathology.

  16. Dynamic Response in Transient Stress-Field Behavior Induced by Hydraulic Fracturing

    Jenkins, Andrew

    Hydraulic fracturing is a technique which is used to exploit geologic features and subsurface properties in an effort to increase production in low-permeability formations. The process of hydraulic fracturing provides a greater surface contact area between the producing formation and the wellbore and thus increases the amount of recoverable hydrocarbons from within the reservoir. The use of this stimulation technique has brought on massive applause from the industry due to its widespread success and effectiveness, however the dynamic processes that take part in the development of hydraulic fractures is a relatively new area of research with respect to the massive scale operations that are seen today. The process of hydraulic fracturing relies upon understanding and exploiting the in-situ stress distribution throughout the area of study. These in-situ stress conditions are responsible for directing fracture orientation and propagation paths throughout the period of injection. The relative magnitude of these principle stresses is key in developing a successful stimulation plan. In horizontal well plan development the interpretation of stress within the reservoir is required for determining the azimuth of the horizontal well path. These horizontal laterals are typically oriented in a manner such that the well path lies parallel to the minimum horizontal stress. This allows for vertical fractures to develop transversely to the wellbore, or normal to the least principle stress without the theoretical possibility of fractures overlapping, creating the most efficient use of the fluid energy during injection. The orientation and magnitude of these in-situ stress fields however can be dynamic, controlled by the subsequent fracture propagation and redistribution of the surrounding stresses. That is, that as the fracture propagates throughout the reservoir, the relative stress fields surrounding the fractures may see a shift and deviate from their original direction or

  17. The Tromsø Study: physical activity and the incidence of fractures in a middle-aged population.

    Joakimsen, R M; Fønnebø, V; Magnus, J H; Størmer, J; Tollan, A; Søgaard, A J


    We have studied the relation of occupational and recreational physical activity to fractures at different locations. All men born between 1925 and 1959 and all women born between 1930 and 1959 in the city of Tromsø were invited to participate in surveys in 1979-1980 and 1986-1987 (The Tromsø Study). Of 16,676 invited persons, 12,270 (73.6%) attended both surveys. All nonvertebral fractures (n = 1435) sustained from 1988 to 1995 were registered in the only hospital in the area. Average age in the middle of the follow-up period (December 31, 1991) was 47.3 years among men and 4501 years among women, ranging from 32 to 66 years. Fracture incidence increased with age at all locations among women, but it decreased with or was independent of age among men. Low-energetic fractures constituted 74.4% of all fractures among women and 55.2% among men. When stratifying by fracture location, the most physically active persons among those 45 years or older suffered fewer fractures in the weight-bearing skeleton (relative risk [RR] 0.6, confidence interval [CI] 0.4-0.9, age-adjusted), but not in the non-weight-bearing skeleton (RR 1.0, CI 0.7-1.2, age-adjusted) compared with sedentary persons. The relative-risk of a low-energetic fracture in the weight-bearing skeleton among the most physically active middle-aged was 0.3 (CI 0.1-0.7) among men and 0.9 (CI 0.4-1.8) among women compared with the sedentary when adjusted for age, body mass index, body height, tobacco smoking, and alcohol and milk consumption. It seems that the beneficial effect on the skeleton of weight-bearing activity is reflected also in the incidence of fractures at different sites.

  18. Incidence of posttraumatic stress disorder after traffic accidents in Germany.

    Brand, Stephan; Otte, Dietmar; Petri, Maximilian; Decker, Sebastian; Stübig, Timo; Krettek, Christian; Müller, Christian W


    Posttraumatic stress disorder (PTSD) is possibly an overlooked diagnosis of victims suffering from traffic accidents sustaining serious to severe injuries. This paper investigates the incidence of PTSD after traffic accidents in Germany. Data from an accident research unit were analyzed in regard to collision details, and preclinical and clinical data. Preclinical data included details on crash circumstances and estimated injury severity as well as data on victims' conditions (e.g. heart rate, blood pressure, consciousness, breath rate). Clinical data included initial assessment in the emergency department, radiographic diagnoses, and basic life parameters comparable to the preclinical data as well as follow-up data on the daily ward. Data were collected in the German-In-Depth Accident Research study, and included gender, type of accident (e.g. type of vehicle, road conditions, rural or urban area), mental disorder, and AIS (Abbreviated Injury Scale) head score. AIS represent a scoring system to measure the injury severity of traffic accident victims. A total 258 out of 32807 data sets were included in this analysis. Data on accident and victims was collected on scene by specialized teams following established algorithms. Besides higher AIS Head scores for male motorcyclists compared to all other subgroups, no significant correlation was found between the mean maximum AIS score and the occurrence of PTSD. Furthermore, there was no correlation between higher AIS head scores, gender, or involvement in road traffic accidents and PTSD. In our study the overall incidence of PTSD after road traffic accidents was very low (0.78% in a total of 32.807 collected data sets) when compared to other published studies. The reason for this very low incidence of PTSD in our patient sample could be seen in an underestimation of the psychophysiological impact of traffic accidents on patients. Patients suffering from direct experiences of traumatic events such as a traffic accident

  19. Analyses of thermal stress and fracture during cryopreservation of blood vessel

    华泽钊; 徐红艳; 周国燕; 刘锦纷; 黄惠民; 丁文祥


    The occurrence of fractures in the vessel wall has been a major problem for human blood vessel cryopreservation. The large volumetric expansion of water during crystallization produces great inner stresses. To solve these complicated heat transfer and thermal stress problems, a model and an analytic method are presented in this paper, with which transient temperature field, the transient stress field inside the blood vessels during freezing can be calculated and analyzed, and the probable cracks or fractures can be predicted. The analytic results of sheep thoracic artery are consistent with the experimental observations of fractures.

  20. Regional Flow Simulation in Fractured Aquifers Using Stress-Dependent Parameters

    Preisig, G; Perrochet, P


    A model function relating effective stress to fracture permeability is developed from Hooke's law, implemented in the tensorial form of Darcy's law, and used to evaluate discharge rates and pressure distributions at regional scales. The model takes into account elastic and statistical fracture parameters, and is able to simulate real stress-dependent permeabilities from laboratory to field studies. This modeling approach gains in phenomenology in comparison to the classical ones because the permeability tensors may vary in both strength and principal directions according to effective stresses. Moreover this method allows evaluation of the fracture porosity changes, which are then translated into consolidation of the medium.

  1. Estimating the effect of incident delirium on short-term outcomes in aged hip fracture patients through propensity score analysis.

    Radinovic, Kristina; Markovic-Denic, Ljiljana; Dubljanin-Raspopovic, Emilija; Marinkovic, Jelena; Milan, Zoka; Bumbasirevic, Vesna


    We aimed to evaluate the factors contributing to delirium after hip fracture and assess the effect of incident delirium on short-term clinical outcomes. A total of 270 non-delirious, consecutive hip fracture patients 60 years and older were included in a prospective cohort study. The patients were assessed with respect to physical status according to the American Society of Anesthesiologists classification, medical comorbidities with the Charlson Comorbidity Index, cognitive function with the Portable Mental Status Questionnaire and depression with the Geriatric Depressive Scale. Incident delirium was evaluated daily. Clinical outcomes and 1-month mortality were recorded. Incident delirium was present in 53.0% of patients. Patients with delirium were older (P = 0.046), had higher American Society of Anesthesiologists and Charlson Comorbidity Index scores (P Scale scores (P risk of reintervention plus death (P propensity score, patients with delirium were at higher risk of reintervention plus death (P < 0.05) and longer length of hospital stay (P < 0.01). Patients who are older, with worse physical status, worse cognitive function and depression are more likely to develop delirium after hip fracture. Incident delirium has negative independent effects on short-term outcomes in elderly patients after hip fracture. © 2014 Japan Geriatrics Society.

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

    Bahari, Syah


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

  3. Contralateral hip fractures and other osteoporosis-related fractures in hip fracture patients: Incidence and risk factors. An observational cohort study of 1,229 patients

    A.J.H. Vochteloo (Anne); B.L. Borger van der Burg (Boudewijn); M.L. Röling (Maarten); D.H.-J. van Leeuwen (Diederik); P. van den Berg (Peter); A.H.P. Niggebrugge (Arthur); M.R. de Vries (Mark); W.E. Tuinebreijer (Wim); R.M. Bloem (Rolf); R.G.H.H. Nelissen (Rob); P. Pilot (Peter)


    textabstractPurpose: To report risk factors, 1-year and overall risk for a contralateral hip and other osteoporosis-related fractures in a hip fracture population. Methods: An observational study on 1,229 consecutive patients of 50 years and older, who sustained a hip fracture between January 2005

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

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


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


    Ji Changjiang; Li Zhonghua; Sun Jun


    A closed-form solution for predicting the tangential stress of an inclusion located in mixed mode Ⅰ and Ⅱ crack tip field was developed based on the Eshelby equivalent inclusion theory. Then a mixed mode fracture criterion, including the fracture direction and the critical load, was established based on the maximum tangential stress in the inclusion for brittle inclusioninduced fracture materials. The proposed fracture criterion is a function of the inclusion fracture stress, its size and volume fraction, as well as the elastic constants of the inclusion and the matrix material. The present criterion will reduce to the conventional one as the inclusion having the same elastic behavior as the matrix material. The proposed solutions are in good agreement with detailed finite element analysis and measurement.

  6. High serum adiponectin predicts incident fractures in elderly men: Osteoporotic fractures in men (MrOS) Sweden.

    Johansson, Helena; Odén, Anders; Lerner, Ulf H; Jutberger, Hans; Lorentzon, Mattias; Barrett-Connor, Elizabeth; Karlsson, Magnus K; Ljunggren, Osten; Smith, Ulf; McCloskey, Eugene; Kanis, John A; Ohlsson, Claes; Mellström, Dan


    Adipocytes and osteoblasts share a common progenitor, and there is, therefore, potential for both autocrine and endocrine effects of adiponectin on skeletal metabolism. The aim of the present study was to determine whether high serum adiponectin was associated with an increased risk of fracture in elderly men. We studied the relationship between serum adiponectin and the risk of fracture in 999 elderly men drawn from the general population and recruited to the Osteoporotic Fractures in Men (MrOS) study in Gothenburg, Sweden. Baseline data included general health questionnaires, lifestyle questionnaires, body mass index (BMI), bone mineral density (BMD), serum adiponectin, osteocalcin, and leptin. Men were followed for up to 7.4 years (average, 5.2 years). Poisson regression was used to investigate the relationship between serum adiponectin, other risk variables and the time-to-event hazard function of fracture. Median levels of serum adiponectin at baseline were 10.4 µg/mL (interquartile range, 7.7-14.3). During follow-up, 150 men sustained one or more fractures. The risk of fracture increased in parallel with increasing serum adiponectin (hazard ratio [HR]/SD, 1.46; 95% confidence interval [CI], 1.23-1.72) and persisted after multivariate-adjusted analysis (HR/SD, 1.30; 95% CI, 1.09-1.55). Serum adiponectin shows graded stepwise association with a significant excess risk of fracture in elderly men that was independent of several other risk factors for fracture. Its measurement holds promise as a risk factor for fracture in men.

  7. The effect of multiaxial stress state on creep behavior and fracture mechanism of P92 steel

    Chang, Yuan; Xu, Hong, E-mail:; Ni, Yongzhong; Lan, Xiang; Li, Hongyuan


    The creep experiments on plain and double U-typed notched specimens were conducted on P92 steel at 650 °C. The notch strengthening effect was found in the notched specimens. Fracture appearance observed by scanning electron microscopy revealed that dimpled fracture for relatively blunt notched specimen, and dimpled fracture doubled with intergranular brittle fracture for relatively sharp notched specimen, which meant that fracture mechanism of P92 steel altered due to the presence of the notch. Meanwhile, based on Norton–Bailey and Kachanov–Robotnov constitutive models, a modified model was proposed. Finite element simulations were carried out to investigate the effect of multiaxial stress state on the creep behavior, fracture mechanism and damage evolvement of P92 steel. The simulation results agreed well with the fracture behaviors observed experimentally.

  8. Associations between Fracture Incidence and Use of Depot Medroxyprogesterone Acetate and Anti-Epileptic Drugs in Women with Developmental Disabilities

    Lentz, Martha J.; Cain, Kevin C.


    Purpose To evaluate any association between incidence of osteoporotic fractures and use of depot medroxyprogesterone acetate (DMPA) and/or anti-epileptic drugs (AEDs) among women and girls with developmental disabilities. Methods Cross-sectional population–based observational study of all non-institutionalized females with developmental disabilities age thirteen and older who received fee-for-service Medicaid in Washington State during 2002 (N=6773), using administrative data. Main Findings In a sample of 6,773 females, 140 women (2%) had an osteoporotic fracture during 2002. Among 340 users of DMPA, 13 (3.8%) had an osteoporotic fracture with an odds ratio of 2.4 (CI 95%, 1.3–4.4) for fracture compared to non-users. Among 1909 users of AEDs, 60 (3.1%) had an osteoporotic fracture with an odds ratio of 1.9 (CI 95%, 1.3–2.6) for fracture compared to non-users. We controlled for age and race (as Caucasian or non-Caucasian). Conclusions Use of either AEDs or DMPA by women with developmental disabilities is associated with significantly increased incidence of fracture. Women and girls who have developmental disabilities may be poor candidates for DMPA use due to increased risk of fractures. Further research is indicated (1) to determine the specific risks profile of DMPA for this population, (2) to explore alternative means of managing significant menstrual problems and contraceptive needs in this population and (3) to screen current and previous users of DMPA and chronic users of AEDs for osteoporosis risk, regardless of age. PMID:17188217

  9. The impact of in-situ stress and outcrop-based fracture geometry on hydraulic aperture and upscaled permeability in fractured reservoirs

    Bisdom, Kevin; Bertotti, Giovanni; Nick, Hamidreza M.


    Aperture has a controlling impact on porosity and permeability and is a source of uncertainty in modeling of naturally fractured reservoirs. This uncertainty results from difficulties in accurately quantifying aperture in the subsurface and from a limited fundamental understanding of the mechanical and diagenetic processes that control aperture. In the absence of cement bridges and high pore pressure, fractures in the subsurface are generally considered to be closed. However, experimental work, outcrop analyses and subsurface data show that some fractures remain open, and that aperture varies even along a single fracture. However, most fracture flow models consider constant apertures for fractures. We create a stress-dependent heterogeneous aperture by combining Finite Element modeling of discrete fracture networks with an empirical aperture model. Using a modeling approach that considers fractures explicitly, we quantify equivalent permeability, i.e. combined matrix and stress-dependent fracture flow. Fracture networks extracted from a large outcropping pavement form the basis of these models. The results show that the angle between fracture strike and σ1 has a controlling impact on aperture and permeability, where hydraulic opening is maximum for an angle of 15°. At this angle, the fracture experiences a minor amount of shear displacement that allows the fracture to remain open even when fluid pressure is lower than the local normal stress. Averaging the heterogeneous aperture to scale up permeability probably results in an underestimation of flow, indicating the need to incorporate full aperture distributions rather than simplified aperture models in reservoir-scale flow models.

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

    Murphy, Colin G


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

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

    Murphy, Colin G; O'Flanagan, Shay; Keogh, Peter; Kenny, Patrick


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

  12. Expected Time to Return to Athletic Participation Following Stress Fracture in Division I Collegiate Athletes

    Jamieson, Marissa; Everson, Sonsecharae; Siegel, Courtney; Miller, Timothy Lee


    Objectives: The objective of this study was to evaluate and determine the expected time to return to athletic participation in Division I collegiate Track and Field athletes. Methods: All stress fractures diagnosed in athletes on a single Division I collegiate men’s and women’s track and field/ cross-country team were recorded over a 4-year period. Site and severity of the injury were recorded and graded based on the Kaeding-Miller Classification System for stress fractures. Time to return to full unrestricted athletic participation was recorded for each athlete and correlated with the site and severity grade of the injury. Time to return to athletic participation was also analyzed for gender differences. Results: Fifty-seven stress fractures were diagnosed in 38 athletes over a 4-year period. Thirty-seven of these injuries occurred in women; twenty in men. Mean time to return to participation in women was 13.9 weeks and 11.2 weeks in men. There were 10 athletes who sustained recurrent or multiple stress fractures. Thirty-three stress fractures occurred in the tibia, and 10 occurred in the 2nd through 4th metatarsals. Three occurred in the 5th metatarsal, 6 in the tarsal bones (2 navicular), and 5 in the pelvis. Mean times to return to athletic activity based on site of injury and with extreme outliers removed were as follows: tibia- 13.3 weeks, 2nd through 4th metatarsals- 11.7 weeks, 5th metatarsal- 11.7 weeks, tarsals- 12.1 weeks, and pelvis- 13.0 weeks. There were 31 grade 2 stress fractures, 11 grade 3 stress fractures, and two grade 5 stress fractures that occurred bilaterally in the same patient. Mean times to return to athletic participation again with extreme outliers excluded were as follows: Grade 2- 12.3 weeks, Grade 3- 14.1 weeks, and Grade 5- 17 weeks. There were no Grade 4 (displaced) stress fractures diagnosed in this cohort of patients. Conclusion: Stress injuries to bone occur frequently in track and field athletes. Based on data collected

  13. Stress fracture of the great toe sesamoid in a ballerina: MRI appearance

    Burton, E.M. [Medical Coll. of Georgia, Augusta (United States). Dept. of Radiology; Amaker, B.H. [Medical Coll. of Georgia, Augusta, GA (United States). Dept. of Pathology


    This case is the first to depict a stress fracture of the great toe sesamoid bone using magnetic resonance imaging. We used a 3`` surface coil to produce high resolution images of the sesamoid. (orig.)

  14. Osteomalacia and coxa vara. An unusual co-existence for femoral neck stress fracture

    Kerim Sariyilmaz


    Conclusion: Joint and bone pain without any trauma should be investigated and bone metabolism disorders should be kept in mind. There might be co-existing factors related with stress fractures, and they must be treated simultaneously.

  15. Discrete fracture in quasi-brittle materials under compressive and tensile stress states

    Klerck, PA


    Full Text Available A method for modelling discrete fracture in geomaterials under tensile and compressive stress fields has been developed based on a Mohr-Coulomb failure surface in compression and three independent anisotropic rotating crack models in tension...

  16. Mid-Anterior Tibial Stress Fracture in a Female Elite Athlete : A Case Report.

    Netzer, Patricia A M


    We report the case of an unusual tibial stress fracture and its successful surgical treatment in a female elite sprinter 2 years after complete consolidation of the same tibia following resection of an osteoid osteoma.

  17. Manubrial stress fractures diagnosed on MRI: report of two cases and review of the literature

    Baker, Jonathan C.; Demertzis, Jennifer L. [Washington University School of Medicine, Mallinckrodt Institute of Radiology, Musculoskeletal Section, St Louis, MO (United States)


    In contrast to widely-reported sternal insufficiency fractures, stress fractures of the sternum from overuse are extremely rare. Of the 5 cases of sternal stress fracture published in the English-language medical literature, 3 were in the sternal body and only 2 were in the manubrium. We describe two cases of manubrial stress fracture related to golf and weightlifting, and present the first report of the MR findings of this injury. In each of these cases, the onset of pain was atraumatic, insidious, and associated with increased frequency of athletic activity. Imaging was obtained because of clinical diagnostic uncertainty. On MRI, each patient had a sagittally oriented stress fracture of the lateral manubrium adjacent to the first rib synchondrosis. Both patients had resolution of pain after a period of rest, with subsequent successful return to their respective activities. One patient had a follow-up MRI, which showed resolution of the manubrial marrow edema and fracture line. Based on the sternal anatomy and MR findings, we hypothesize that this rare injury might be caused by repetitive torque of the muscle forces on the first costal cartilage and manubrium, and propose that MRI might be an effective means of diagnosing manubrial stress fracture. (orig.)

  18. Bilateral periprosthetic stress fractures in a juvenile chronic arthritis patient secondary to bilateral genu valgum.

    Al-Khateeb, H; Meir, A; Singer, G C


    Lateral insufficiency fractures following total hip replacement have been reported with the femoral stems positioned in varus, together with osteopenia of the lateral femoral cortex. Any abnormal alignment of the lower limbs, such as genu valgum, will alter the load distribution across the femoral cortices, and repetitive loading during walking will predispose the bones to stress fractures at any stress riser point, such as the tip of a femoral component. Bilateral femoral stress fractures post total hip replacements have not been previously described. We present a 55-year-old woman, diagnosed with juvenile idiopathic arthritis, who had undergone bilateral total hip replacements and bilateral knee replacements. The knees 15 years postoperatively were in valgus and the left knee was extremely stiff, flexing to just 5. The patient presented with bilateral thigh pain, with plain radiographs confirming bilateral periprosthetic fractures of the femur at the tip of well-fixed femoral components. There was no history of injury and her hips were functioning well up to this time. The patient required revision of both hips to long-stem uncemented components, bypassing the fractures, and revision of both knees to stemmed semi-constrained implants, thereby correcting the alignment of both lower limbs. Both fractures healed and the patient is currently pain-free and mobile with walking aids. Surgeons must remain aware that when implants are in situ, abnormal alignments will lead to abnormal forces, and stress fractures are likely to occur at any stress riser around the implant. Avoiding malalignment will avoid this complication.

  19. Reflections on the Use of Critical Incident Stress Debriefing in Schools

    Aucott, Clare; Soni, Anita


    Providing support to schools following a critical incident has become an established part of service delivery for many Educational Psychology Services (EPSs) in the UK. This article offers reflections on the use of Critical Incident Stress Debriefing (CISD) in schools. A review of the literature on critical incidents, trauma, resilience and…

  20. FEM analysis of deformation localization mechanisms in a 3-D fractured medium under rotating compressive stress orientations

    Strijker, G.; Beekman, F.; Bertotti, G.; Luthi, S.M.


    Stress distributions and deformation patterns in a medium with a pre-existing fracture set are analyzed as a function of the remote compressive stress orientation (σH) using finite element models with increasingly complex fracture configurations. Slip along the fractures causes deformation localizat

  1. FEM analysis of deformation localization mechanisms in a 3-D fractured medium under rotating compressive stress orientations

    Strijker, G.; Beekman, F.; Bertotti, G.; Luthi, S.M.


    Stress distributions and deformation patterns in a medium with a pre-existing fracture set are analyzed as a function of the remote compressive stress orientation (σH) using finite element models with increasingly complex fracture configurations. Slip along the fractures causes deformation

  2. Discontinuation of Denosumab and Associated Fracture Incidence: Analysis From the Fracture Reduction Evaluation of Denosumab in Osteoporosis Every 6 Months (FREEDOM) Trial

    Brown, Jacques P; Roux, Christian; Törring, Ove; Ho, Pei-Ran; Beck Jensen, Jens-Erik; Gilchrist, Nigel; Recknor, Christopher; Austin, Matt; Wang, Andrea; Grauer, Andreas; Wagman, Rachel B


    Osteoporosis is a chronic disease and requires long-term treatment with pharmacologic therapy to ensure sustained antifracture benefit. Denosumab reduced the risk for new vertebral, nonvertebral, and hip fractures over 36 months in the Fracture Reduction Evaluation of Denosumab in Osteoporosis Every 6 Months (FREEDOM) trial. Whereas discontinuation of denosumab has been associated with transient increases in bone remodeling and declines in bone mineral density (BMD), the effect on fracture risk during treatment cessation is not as well characterized. To understand the fracture incidence between treatment groups after cessation of investigational product, we evaluated subjects in FREEDOM who discontinued treatment after receiving two to five doses of denosumab or placebo, and continued study participation for ≥7 months. The off-treatment observation period for each individual subject began 7 months after the last dose and lasted until the end of the study. This subgroup of 797 subjects (470 placebo, 327 denosumab), who were evaluable during the off-treatment period, showed similar baseline characteristics for age, prevalent fracture, and lumbar spine and total hip BMD T-scores. During treatment, more placebo-treated subjects as compared with denosumab-treated subjects sustained a fracture and had significant decreases in BMD. During the off-treatment period (median 0.8 years per subject), 42% versus 28% of placebo- and denosumab-treated subjects, respectively, initiated other therapy. Following discontinuation, similar percentages of subjects in both groups sustained a new fracture (9% placebo, 7% denosumab), resulting in a fracture rate per 100 subject-years of 13.5 for placebo and 9.7 for denosumab (hazard ratio [HR] 0.82; 95% confidence interval [CI], 0.49–1.38), adjusted for age and total hip BMD T-score at baseline. There was no apparent difference in fracture occurrence pattern between the groups during the off-treatment period. In summary, there does not

  3. Spontaneous osteonecrosis of the knee associated with tibial plateau and femoral condyle insufficiency stress fracture

    Narvaez, J.A.; Narvaez, J.; Lama, E.De; Sanchez, A. [Department of Magnetic Resonance Imaging, IDI Hospital Duran i Reynals, Ciutat Sanitaria i Universitaria de Bellvitge, Gran Via s/n, 08907, L' Hospitalet de Llobregat (Barcelona) (Spain)


    The purpose of this article is to describe the association between spontaneous osteonecrosis and insufficiency stress fractures of the knee. To determine whether insufficiency stress fracture is associated with spontaneous osteonecrosis of the knee, we retrospectively reviewed the medical charts and imaging studies of all patients with spontaneous osteonecrosis of the knee, studied by MR imaging, seen in a tertiary hospital over an 8-year period. Four women (age range 66-84 years) presented spontaneous osteonecrosis of the knee associated with insufficiency stress fracture of the medial tibial plateau. One of these patients also presented a concomitant insufficiency stress fracture of the medial femoral condyle. Radiographs were diagnostic of spontaneous osteonecrosis of the medial femoral condyle in three cases, and insufficiency stress fracture of the medial tibial plateau was detected in one case. Magnetic resonance imaging allows the diagnosis of both conditions in all four cases. Spontaneous osteonecrosis of the knee may be associated with insufficiency stress fracture of the medial femoral condyle and the medial tibial plateau. This association provides additional arguments in favor of the traumatic etiology of spontaneous osteonecrosis of knee. (orig.)

  4. The incidence of hip fractures in Norway -accuracy of the national Norwegian patient registry

    Høiberg, Mikkel; Gram, Jeppe; Hermann, Pernille;


    Background: Hip fractures incur the greatest medical costs of any fracture. Valid epidemiological data are important to monitor for time-dependent changes. In Norway, hip fractures are registered in the Norwegian Patient Registry (NPR), but no published national validation exists. The aim...

  5. SUPERPOSE-An excel visual basic program for fracture modeling based on the stress superposition method

    Ismail Ozkaya, Sait


    An Excel Visual Basic program, SUPERPOSE, is presented to predict the distribution, relative size and strike of tensile and shear fractures on anticlinal structures. The program is based on the concept of stress superposition; addition of curvature-related local tensile stress and regional far-field stress. The method accurately predicts fractures on many Middle East Oil Fields that were formed under a strike slip regime as duplexes, flower structures or inverted structures. The program operates on the Excel platform. The program reads the parameters and structural grid data from an Excel template and writes the results to the same template. The program has two routines to import structural grid data in the Eclipse and Zmap formats. The platform of SUPERPOSE is a single layer structural grid of a given cell size (e.g. 50×50 m). In the final output, a single tensile or two conjugate shear fractures are placed in each cell if fracturing criteria are satisfied; otherwise the cell is left blank. Strike of the representative fracture(s) is calculated and exact, but the length is an index of fracture porosity (fracture density×length×aperture) within that cell.

  6. Some effects of stress, friction and fluid flow on hydraulic fracturing

    Hanson, M.E.; Anderson, G.D.; Shaffer, R.J.; Thorson, L.D.


    We are conducting a DOE funded research program which is aimed at understanding the hydraulic fracturing process, especially those phenomena and parameters which strongly affect or control the fracture geometry. Our theoretical and experimental studies consistently confirm the well known fact that in-situ stress has a primary effect on fracture geometry and that fractures propagate perpendicular to the least principal stress. In addition, we find that frictional interfaces in reservoirs can affect fracturing. We have also quantified some of the effects on fracture geometry due to frictional slippage along interfaces. We found that variation of friction along an interface can result in abrupt steps in the fracture path. These effects have been seen in the mine back of emplaced fractures and are demonstrated both theoretically and in the laboratory. Further experiments and calculations are starting to indicate the possible control of the fracture height by the vertical change in the cables to X-608A wells should be replaced, and develop v across categories of persons affected. Respondents were selected according to a purposive sampling strategy, wn are also included. The management plan for the operation of the plant is discussed. (DMC)

  7. kISMET: Stress and fracture characterization in a deep mine

    Oldenburg, C. M.; Dobson, P. F.; Daley, T. M.; Birkholzer, J. T.; Cook, P. J.; Ajo Franklin, J. B.; Rutqvist, J.; Siler, D.; Kneafsey, T. J.; Nakagawa, S.; Wu, Y.; Guglielmi, Y.; Ulrich, C.; Marchesini, P.; Wang, H. F.; Haimson, B. C.; Sone, H.; Vigilante, P.; Roggenthen, W.; Doe, T.; Lee, M.; Mattson, E.; Huang, H.; Johnson, T. C.; Morris, J.; White, J. A.; Johnson, P. A.; Coblentz, D. D.; Heise, J.


    We are developing a community facility called kISMET (permeability (k) and Induced Seismicity Management for Energy Technologies) at the Sanford Underground Research Facility (SURF) in Lead, SD. The purpose of kISMET is to investigate stress and the effects of rock fabric on hydraulic fracturing. Although findings from kISMET may have broad applications that inform stress and fracturing in anisotropic rock, results will be most applicable to improving control of hydraulic fracturing for enhanced geothermal systems (EGS) in crystalline rock. At the kISMET site on the 4850 ft (1480 m depth) level of SURF, we have drilled and cored an array of nearly vertical boreholes in Precambrian phyllite. The array consists of four 50-m deep monitoring boreholes surrounding one 100-m deep borehole forming a 6 m-wide five-spot pattern at a depth of 1530 m. Previous investigations of the stress field at SURF suggest that the principal stress s1 is nearly vertical. By aligning the kISMET boreholes approximately with σ1, fractures created in the center borehole should in theory be perpendicular to σ3, the least principal horizontal stress. But the phyllite at kISMET has a strong fabric (foliation) that could influence fracturing. Stress measurements and stimulation using hydraulic fracturing will be carried out in the center borehole using a straddle packer and high-pressure pump. We will use an impression packer and image logs after stress testing and stimulation to determine fracture orientation and extent at the center borehole. In order to study the control of stress, rock fabric, and stimulation approach on size, aperture, and orientation of hydraulic fractures, we will carefully monitor the stress measurements and stimulation. For example, we will use continuous active source seismic (CASSM) in two of the monitoring boreholes to measure changes in seismic-wave velocity as water fills the fracture. Second, near real-time electrical resistance tomography (ERT) will be used in

  8. Diagnostic accuracy of magnetic resonance imaging versus computed tomography in stress fractures of the lumbar spine

    Ganiyusufoglu, A.K., E-mail: [Department of Radiology, Florence Nightingale Hospital, Istanbul (Turkey); Onat, L. [Department of Radiology, Florence Nightingale Hospital, Istanbul (Turkey); Karatoprak, O.; Enercan, M.; Hamzaoglu, A. [Department of Orthopedics and Traumatology, Florence Nightingale Hospital, Istanbul (Turkey)


    Aim: To compare the diagnostic accuracy of magnetic resonance imaging (MRI) with computed tomography (CT) in stress fractures of the lumbar spine. Materials and methods: Radiological and clinical data from 57 adolescents and young adults with a diagnosis of stress injury of the lumbar spine were retrospectively reviewed. All cases had undergone both 1.5 T MRI and 16-section CT examinations. All MRI and CT images were retrospectively reviewed and evaluated in separate sessions. The fracture morphology (complete/incomplete, localization) and vertebral levels were noted at both the CT and MRI examinations. Bone marrow/peri-osseous soft-tissue oedema was also determined at MRI. Results: In total, 73 complete and 32 incomplete stress fractures were detected with CT. Sixty-seven complete, 24 incomplete fractures and eight stress reactions were detected using MRI in the same study group. Marrow oedema was also seen in eight of the complete and 20 of the incomplete fractures. The specificity, sensitivity, and accuracy of MRI in detecting fracture lines were 99.6, 86.7, and 97.2%, respectively. MRI was more accurate at the lower lumbar levels in comparison to upper lumbar levels. Conclusion: MRI has a similar diagnostic accuracy to CT in determining complete fractures with or without accompanying marrow oedema and incomplete fractures with accompanying marrow oedema, especially at the lower lumbar levels, which constitutes 94% of all fractures. At upper lumbar levels and in the incomplete fractures of the pars interarticularis with marked surrounding sclerosis, MRI has apparent limitations compared to CT imaging.

  9. Marrow changes in anorexia nervosa masking the presence of stress fractures on MR imaging

    Tins, B.; Cassar-Pullicino, V. [Department of Radiology, RJAH Orthopaedic and District Hospital, Oswestry (United Kingdom)


    Patients with anorexia nervosa (AN) usually have abnormal bone and bone marrow metabolism resulting in osteopenia and serous bone marrow change. There is an increased risk of stress/insufficiency fractures and these can be the first presentation of AN. This case report describes a patient with previously undiagnosed AN who presented with foot pain. The serous bone marrow changes of AN were found to mask the MR imaging features of stress fractures, as both had low T1w and high T2w and STIR signal intensities. Contrast enhancement was not helpful but actually masked fractures. Scintigraphy was helpful. The radiologist might be the first clinician to raise the possibility of AN and should be aware of the difficulties in diagnosing stress fractures in bones with underlying serous bone marrow change. In this severe case of AN even the heel fat pad and the fat pad in Kager's triangle had undergone serous change.

  10. Influence of fractality of fracture surfaces on stress and displacement fields at crack tips


    In the classic theory of fracture mechanics,expressions for calculating the stresses and displacements in the vicinity of the crack tip are deduced on the basis of the assumption that a fracture surface is a smooth surface or that a crack is a smooth crack.In fact,the surface of a crack formed during the fracture is usually very irregular.So the real asymptotic form of the stress and displacement fields at the crack tip is different from the classic one.Considering the irregularity of a real fracture surface or a real crack profile,the crack is taken as a fractal one,and then the real asymptotic form at the crack tip is developed by applying Griffith’s energy balance principle and fractal geometry.Through the developed asymptotic form,it is discovered that the fractality of the crack reduces the stress singularity at the crack tip.

  11. Stress dependence of permeability of intact and fractured shale cores.

    van Noort, Reinier; Yarushina, Viktoriya


    Whether a shale acts as a caprock, source rock, or reservoir, understanding fluid flow through shale is of major importance for understanding fluid flow in geological systems. Because of the low permeability of shale, flow is thought to be largely confined to fractures and similar features. In fracking operations, fractures are induced specifically to allow for hydrocarbon exploration. We have constructed an experimental setup to measure core permeabilities, using constant flow or a transient pulse. In this setup, we have measured the permeability of intact and fractured shale core samples, using either water or supercritical CO2 as the transporting fluid. Our measurements show decreasing permeability with increasing confining pressure, mainly due to time-dependent creep. Furthermore, our measurements show that for a simple splitting fracture, time-dependent creep will also eliminate any significant effect of this fracture on permeability. This effect of confinement on fracture permeability can have important implications regarding the effects of fracturing on shale permeability, and hence for operations depending on that.

  12. Incidence of tendon entrapment and dislocation with calcaneus and pilon fractures on CT examination

    Tresley, Jonathan [Jackson Memorial Hospital, Department of Diagnostic Radiology, Miami, FL (United States); University of Wisconsin-Madison, Department of Radiology, Madison, WI (United States); Subhawong, Ty K.; Singer, Adam D.; Clifford, Paul D. [Jackson Memorial Hospital, Department of Diagnostic Radiology, Miami, FL (United States)


    To examine the association between tibial pilon and calcaneal fracture classification and tendon entrapment or dislocation. After institutional review board approval, we retrospectively reviewed consecutive CT scans with calcaneal or pilon fractures from 5 years at a level 1 trauma center. We categorized calcaneal fractures according to the Sanders classification, and pilon fractures according to the Ruedi and Allgower and the Arbeitsgemeinschaft fuer Osteosynthesefragen-Orthopaedic Trauma Association (AO-OTA) classifications. Ankle tendons were assessed for dislocation or entrapment. Fisher's exact test was used for statistical analysis with significance at p < 0.05. A total of 312 fractures (91 pilon only, 193 calcaneal only, and 14 ankles with ipsilateral pilon and calcaneal fractures) were identified in 273 patients. Twenty-two pilon, 42 calcaneal, and nine combination fractures were associated with 99 occurrences of tendon entrapment or superior peroneal retinacular injury. Such findings were associated with multiple fractures (p = 0.002). Multifragmentary pilon fractures were associated with posterior tibial and flexor digitorum longus tendon entrapment (p < 0.0001 and p = 0.0003 for Ruedi/Allgower and AO-OTA, respectively), and multifragmentary Sanders type 3 or 4 calcaneal fractures were associated with superior peroneal retinacular injury (p = 0.0473) compared to simple fracture patterns. Thirty-nine percent of tendon entrapments or retinacular injuries were prospectively identified, 85 % by musculoskeletal radiologists (p < 0.0001). Approximately 25 % of calcaneal and pilon fractures were retrospectively identified to contain posteromedial tendon entrapment or superior peroneal retinacular injury. Radiologists should meticulously search for such injuries, particularly when analyzing multifragmentary and multiple fractures. (orig.)

  13. Subchondral stress fracture of femoral head in a healthy adult

    Anand Ashish


    Full Text Available Subchondral fracture of the femoral head is an uncommon entity and usually occurs as an insufficiency fracture associated with poor bone quality or as a fatigue fracture in young military recruits. This condition should be considered in the differential diagnosis of acute hip pain in young patients along with transient osteoporosis and avascular necrosis of the hip. We report a case of acute onset hip pain in an asymptomatic healthy adult in which the diagnosis was made by magnetic resonance imaging and the patient responded well to conservative treatment.

  14. The Role of the Critical Incident Stress Debriefing (CISD) Process in Disaster Counseling.

    Everly, George S., Jr.


    Posttraumatic stress is an occupational hazard for certain high-risk groups such as personnel in emergency services, public safety, and disaster response. Critical Incident Stress Debriefing (CISD) represents a structured group intervention designed for the mitigation of posttraumatic stress. Provides an introduction to and an overview of the CISD…

  15. Bilateral stress fractures of femoral neck in non-athletes: a report of four cases

    Naik Monappa A


    Full Text Available 【Abstract】Femoral neck stress fractures (FNSFs are rare, constituting only 5% of all stress fractures in young adults. These fractures are usually seen in athletes, military recruits and patients with underlying metabolic diseases. The treatment of FNSFs is still controversial because of the inherent complications associated with the treatment procedure. We came across 4 cases of bilateral FNSFs in non-athletic individuals who were manual labourers with-out underlying bony disorders. Two patients with FNSFs and coxa vara deformity on both sides were managed by subtrochanteric valgus osteotomy and dynamic hip screw fixation. One of the remaining two patients was treated by cannulated cancellous screw fixation on one side and sub-trochanteric valgus osteotomy on the other side. The fourth patient received subtrochanteric valgus osteotomy on one side and bipolar hemiarthroplasty on the other side after failed cannulated screw fixation. All the fractures healed without any complications. No evidence of avascular ne-crosis or arthritis was noted in our series. Subtrochanteric valgus osteotomy restores normal neck-shaft angle in pa-tients suffering from FNSFs combined with coxa vara deformity. Moreover, it helps to bring the forces acting around the hip to normal biomechanical levels, leading to fracture union and better results. Replacement arthroplasty is recommended to patients who fail to achieve bony union after fixation. Key words: Fractures, stress; Femoral neck fractures; Coxa vara; Osteotomy

  16. Thermoelastic stresses induced by non-isothermal fluid injection into fractured rock

    Mossop, A.; Matthai, S. K.


    The injection of cold water into hot fractured rock occurs in a number of industrial scenarios, most commonly in the recharge of geothermal reservoirs and during waterflood operations in hydrocarbon reservoirs. The cold water cools the rock local to the fracture flow pathways, the cooled rock contracts, causing localised stress perturbations. Essentially analogous physical processes are involved in the injection of hot fluids into cooler rock such as occur in steam flood operations in viscous oil recovery. In this study we investigate such thermoelastic stresses induced by non-isothermal injection into a three dimensional fractured rock mass. The starting point of our analysis is an idealized model of injection into a single, uniform, horizontal fracture. For this case we have previously found semi-analytic solutions and analytic estimates of the stress perturbation and these are in turn used for cross-verification of an isoparametric, quadratic, finite element model of the system. In the numerical model the fractures are treated as discrete conductive channels within the matrix and an additional feature is that the matrix itself can be assigned a non-zero permeability. As the numerical simulator follows a fundamentally different methodology for solving these thermoelastic problems, the results help to validate some of the scaling relationships and non-intuitive behaviour deduced from the analytic estimates (e.g. for a broad range of flow rates, fracture normal stress perturbations decrease with increasing injection rates). The finite element model is then used to explore progressively more complex fracture geometries and networks. Finally we investigate the validity of a continuum limit as fracture densities increase to the point that fracture separation length scales are comparable with thermal diffusion length scales.

  17. 16-Detector multislice CT in the detection of stress fractures: a comparison with skeletal scintigraphy

    Groves, A.M. [Department of Radiology, Addenbrooke' s Hospital NHS Trust, University of Cambridge, Cambridge (United Kingdom)]. E-mail:; Cheow, H.K. [Department of Nuclear Medicine, Addenbrooke' s Hospital NHS Trust, University of Cambridge, Cambridge (United Kingdom); Balan, K.K. [Department of Nuclear Medicine, Addenbrooke' s Hospital NHS Trust, University of Cambridge, Cambridge (United Kingdom); Housden, B.A. [Department of Radiology, Addenbrooke' s Hospital NHS Trust, University of Cambridge, Cambridge (United Kingdom); Bearcroft, P.W.P. [Department of Radiology, Addenbrooke' s Hospital NHS Trust, University of Cambridge, Cambridge (United Kingdom); Dixon, A.K. [Department of Radiology, Addenbrooke' s Hospital NHS Trust, University of Cambridge, Cambridge (United Kingdom)


    AIMS: To test the hypothesis that the improved resolution afforded by 16-detector computed tomography (CT) would translate to better stress fracture detection when compared with skeletal scintigraphy. MATERIALS AND METHODS: Thirty-three cases of suspected stress fractures in 26 patients were investigated using skeletal scintigraphy and 16-detector CT performed on the same day. Planar images of the lower limbs were taken 3 h post-injection of 400 MBq {sup 99m}Tc-methylene diphosphonate ({sup 99m}Tc-MDP). {sup 99m}Tc-MDP uptake was quantified at suspected fracture sites. CT was performed using a 16-detector multisection machine employing 0.75 mm detectors and images reconstructed in 0.5 mm increments. Examinations were reported independently and discordant results were compared at follow-up. RESULTS: At initial reporting scintigraphy identified fractures in 13 of the 33 cases and CT identified four of the 33. In one case, on review of the CT images, a fracture was present in the distal fibula that was not initially identified. This resulted in eight scintigraphic-positive CT-negative discordant cases. The {sup 99m}Tc-MDP uptake was significantly lower in the discordant fracture group compared with the concordant group (p<0.01). CONCLUSIONS: Despite technological advances in CT, scintigraphy appeared to detect more stress fractures. As such, multidetector CT should not be used as a routine initial investigation in stress fracture detection. The potential use of {sup 99m}Tc-MDP quantification at fracture sites is of interest and may be worth further investigation.

  18. Critical incident stress debriefing: a health promotion model for workplace violence.

    Antai-Otong, D


    To view the global impact of violence as a critical incident. Published literature, author's experience. Psychiatric nurses can use the critical incident stress debriefing protocol to minimize adverse outcomes after a traumatic event. Workplace violence threatens the safety and well-being of nurses. Psychiatric nurses are more likely to encounter workplace violence than nurses in other settings and must prepare themselves using proactive health-promoting activities, for example the critical incident stress debriefing (CISD) model. This health-promotion model provides immediate emotional support and education about normal stress reactions, and may reduce the risk of chronic and disabling emotional and physical consequences.

  19. 99mTc-MDP bone scintigraphy in the diagnosis of stress fracture of the metatarsal bones mimicking oligoarthritis

    Jauković Ljiljana


    Full Text Available Background. Stress fractures are the injuries of soft tissues and bones caused by intensive and repeated stress on a bone. Repeated submaximal stress disturbs the balance between the processes of bone production and resorption that results in fracture. Case report. We presented a case of a patient with stress fracture of metatarsal bone. The patient was diagnosed and treated as having reactive oligoarthritis caused by Chlamydia trachomatis and administered antibiotics. Initial plain radiography was negative for bone fracture. Tc-99m bone scintigraphy suggested stress fracture of the second metatarsal. Plain radiography was became positive three weeks later, showing callus formation in the proximal part of the second metatarsal. Conclusion. Bone scintigraphy is a diagnostic test of choice in early diagnosis of stress fracture, and it is important to apply it timely in order to include the entire therapy and prevent complications, as well as to let a patient return to previous daily activites.

  20. Influence of shear and deviatoric stress on the evolution of permeability in fractured rock

    Faoro, Igor; Niemeijer, André; Marone, Chris; Elsworth, Derek


    The evolution of permeability in fractured rock as a function of effective normal stress, shear displacement, and damage remains a complex issue. In this contribution, we report on experiments in which rock surfaces were subject to direct shear under controlled pore pressure and true triaxial stress

  1. Influence of shear and deviatoric stress on the evolution of permeability in fractured rock

    Faoro, Igor; Niemeijer, André; Marone, Chris; Elsworth, Derek

    The evolution of permeability in fractured rock as a function of effective normal stress, shear displacement, and damage remains a complex issue. In this contribution, we report on experiments in which rock surfaces were subject to direct shear under controlled pore pressure and true triaxial stress

  2. Fracture toughness and evaluation of coating strength with an initial residual stress field

    Byakova, A.V.; Gorbach, V.G. [Polytechnic Institute, Kiev (Ukraine)


    The effect of residual elastic stresses on the geometry of cracks which arise with contact and spontaneous failure of brittle coatings made of high-strength compounds is studied. Conditions are established for the correctness of fracture toughness K{sub lc} tests with indentation of a standard Vickers pyramid as applied to surface layers with an inhomogeneous structure and an initial residual stress field. Taking account of the anisotropy of fracture toughness established by experiment a reliable approach is suggested for evaluating the brittle strength of coatings in the presence of residual stresses.

  3. Information on stress conditions in the oceanic crust from oval fractures in a deep borehole

    Morin, R.H.


    Oval images etched into the wall of a deep borehole were detected in DSDP Hole 504B, eastern equatorial Pacific Ocean, from analysis of an acoustic televiewer log. A systematic inspection of these ovals has identified intriguing consistencies in appearance that cannot be explained satisfactorily by a random, coincidental distribution of pillow lavas. As an alternative hypothesis, Mohr-Coulomb failure criterion is used to account for the generation and orientation of similarly curved, stress-induced fractures. Consequently, these oval features can be interpreted as fractures and related directly to stress conditions in the oceanic crust at this site. The azimuth of the oval center corresponds to the orientation of maximum horizontal principal stress (SH), and the oval width, which spans approximately 180?? of the borehole, is aligned with the azimuth of minimum horizontal principal stress (Sh). The oval height is controlled by the fracture angle and thus is a function of the coefficient of internal friction of the rock. -from Author

  4. Emergency and crisis management: critical incident stress management for first responders and business organisations.

    Guenthner, Daniel H


    A literature review was performed on critical incident stress after September 11th, 2001 (9/11), and Hurricanes Katrina and Rita, which focused on the need to implement a holistic critical incident stress management programme for first responders and business organisations. Critical incident stress management is required to handle acute stress and other distress in the face of natural or man-made disasters, including terrorist attacks. A holistic approach to community resilience through a well-planned and implemented critical incident stress management programme has been shown in the literature to promote self-help and self-efficacy of individuals and organisations. The interventions and programme elements defined clearly show how a number of different intervention and prevention strategies will promote business and community resilience and also self-efficacy in a culturally-diverse community and organisation. Implementing a critical incident stress management programme within a responding business organisation is critical because of the fact that first responders are the most susceptible every day to exposure to critical incidents that will affect their mental health; and business employees will suffer some of the same maladies as first responders in the event of a disaster or crisis. Utilising the framework provided, a holistic critical incident stress management programme can be implemented to help reduce the effects of burnout, absenteeism, acute stress, post-traumatic stress, substance use and traumatic stress, and to work to promote community resilience and toughen individuals against the effects of stress. Taking care of the needs of the employees of a business organisation, and of those of first responders, is clearly required.

  5. Effect of stress sensitivity on displacement efficiency in CO2 flooding for fractured low permeability reservoirs

    Wang Rui; Yue Xiangan; Zhao Renbao; Yan Pingxiang; Dave Freeman


    Carbon dioxide flooding is an effective means of enhanced oil recovery for low permeability reservoirs. If fractures are present in the reservoir, CO2 may flow along the fractures, resulting in low gas displacement efficiency. Reservoir pore pressure will fluctuate to some extent during a CO2 flood, causing a change in effective confining pressure. The result is rock deformation and a reduction in permeability with the reduction in fracture permeability, causing increased flow resistance in the fracture space. Simultaneously, gas cross flowing along the fractures is partially restrained. In this work, the effect of stress changes on permeability was studied through a series of flow experiments. The change in the flowrate distribution in a matrix block and contained fracture with an increase in effective pressure were analyzed. The results lead to an implicit comparison which shows that permeability of fractured core decreases sharply with an increase in effective confining pressure. The fracture flowrate ratio declines and the matrix flowrate ratio increases. Fracture flow will partially divert to the matrix block with the increase in effective confining pressure, improving gas displacement efficiency.

  6. Incidence and Predictors of Multiple Fractures Despite High Adherence to Oral Bisphosphonates: A Binational Population-Based Cohort Study.

    Hawley, Samuel; Javaid, M Kassim; Rubin, Katrine H; Judge, Andrew; Arden, Nigel K; Vestergaard, Peter; Eastell, Richard; Diez-Perez, Adolfo; Cooper, Cyrus; Abrahamsen, Bo; Prieto-Alhambra, Daniel


    Oral bisphosphonates (BPs) are highly effective in preventing fractures and are recommended first-line therapies for patients with osteoporosis. We identified the incidence and predictors of oral BP treatment failure, defined as the incidence of two or more fractures while on treatment (≥2 FWOT) among users with high adherence. Fractures were considered from 6 months after treatment initiation and up to 6 months after discontinuation. Data from computerized records and pharmacy invoices were obtained from Sistema d'Informació per al Desenvolupament de l'Investigació en Atenció Primària (SIDIAP; Catalonia, Spain) and Danish Health Registries (Denmark) for all incident users of oral BPs in 2006-2007 and 2000-2001, respectively. Fine and Gray survival models using backward-stepwise selection (p-entry 0.049; p- exit 0.10) and accounting for the competing risk of therapy cessation were used to identify predictors of ≥2 FWOT among patients having persisted with treatment ≥6 months with overall medication possession ratio (MPR) ≥80%. Incidence of ≥2 FWOT was 2.4 (95% confidence interval [CI], 1.8 to 3.2) and 1.7 (95% CI, 1.2 to 2.2) per 1000 patient-years (PYs) within Catalonia and Denmark, respectively. Older age was predictive of ≥2 FWOT in both Catalonian and Danish cohorts: subhazard ratio (SHR) = 2.28 (95% CI, 1.11 to 4.68) and SHR = 2.61 (95% CI, 0.98 to 6.95), respectively, for 65 to history of recent or older fracture, SHR = 3.40 (95% CI, 1.50 to 7.68) and SHR = 2.08 (95% CI: 1.04-4.15), respectively (Denmark). Even among highly adherent users of oral BP therapy, a minority sustain multiple fractures while on treatment. Older age was predictive of increased risk within both study populations, as was history of recent/old fracture and dementia within one but not both populations. Additional and/or alternative strategies should be investigated for these patients. © 2015 American Society for Bone and Mineral Research.

  7. Rapid rehabilitation programme following sacral stress fracture in a long-distance running female athlete.

    Knobloch, Karsten; Schreibmueller, Louisa; Jagodzinski, Michael; Zeichen, Johannes; Krettek, Christian


    Stress fractures occur in normal bone due to mechanical overload by cyclic stress increasing the osteoclastic activity, thus facilitating weakening leading to fracture of bones. Long-distance running may lead to stress fractures of the mid- and distal tibia and of the metatarsal bones. Stress fractures to the sacrum are rare. Certain factors for stress fractures in runners have been identified, such as leg-length inequality, a high longitudinal arch of the foot, forefoot varus, and menstrual irregularities in case of female athlete triad. We report on a 22-year-old female runner (usually training 140 km/week) suffering a sacral fatigue-type fracture. The female athlete triad with eating disorders, dysmenorrhea, and osteopenia was ruled out. Sexual hormone blood samples proofed normal values. The diagnosis was performed using magnetic resonance imaging 2 weeks after the onset of buttock pain. A conservative treatment regimen was initiated with strict physical rest for the first 2 weeks, and then gradual increase of physical activity with 60-90 min of daily cycling and moderate 2 x 60 min cross-training. After another 2 weeks time, daily 60-90 min of walking, Nordic pole walking, and moderate strength training two times a week was performed. At 7 weeks running was started, gradually increased to 90 km/week without any pain. A rapid rehabilitation programme after sacral stress fractures involving low impact physical activity, such as Walking and Nordic pole walking, is applicable to female athletes after ruling out the female athlete triad.

  8. Comparative trends in incident fracture rates for all long-term care and community-dwelling seniors in Ontario, Canada, 2002–2012

    Kennedy, C. C.; Ioannidis, G.; Cameron, C.; Croxford, R.; Adachi, J. D.; Mursleen, S.; Jaglal, S.


    Summary In this population-based study, we compared incident fracture rates in long-term care (LTC) versus community seniors between 2002 and 2012. Hip fracture rates declined more rapidly in LTC than in the community. An excess burden of fractures occurred in LTC for hip, pelvis, and humerus fractures in men and hip fractures only in women. Introduction This study compares trends in incident fracture rates between long-term care (LTC) and community-dwelling seniors ≥65 years, 2002–2012. Methods This is a population-based cohort study using administrative data. Measurements were age/sex-adjusted incident fracture rates and rate ratios (RR) and annual percent change (APC). Results Over 11 years, hip fracture rates had a marked decline occurring more rapidly in LTC (APC, −3.49 (95% confidence interval (CI), −3.97, −3.01)) compared with the community (APC, −2.93 (95 % CI, −3.28, −2.57); p< 0.05 for difference in slopes). Humerus and wrist fracture rates decreased; however, an opposite trend occurred for pelvis and spine fractures with rates increasing over time in both cohorts (all APCs, p <0.05). In 2012, incident hip fracture rates were higher in LTC than the community (RRs: women, 1.55 (95 % CI, 1.45, 1.67); men, 2.18 (95 % CI, 1.93, 2.47)). Higher rates of pelvis (RR, 1.48 (95 % CI, 1.22, 1.80)) and humerus (RR, 1.40 (95 % CI, 1.07, 1.84)) fractures were observed in LTC men, not women. In women, wrist (RR, 0.76 (95 % CI, 0.71, 0.81)) and spine (RR, 0.52 (95 % CI, 0.45, 0.61)) fracture rates were lower in LTC than the community; in men, spine (RR, 0.75 (95 % CI, 0.57, 0.98) but not wrist fracture (RR, 0.91 (95 % CI, 0.67, 1.23)) rates were significantly lower in LTC than the community. Conclusion Previous studies in the community have shown declining hip fracture rates over time, also demonstrated in our study but at a more rapid rate in LTC. Rates of humerus and wrist fractures also declined. An excess burden of fractures in LTC occurred for hip

  9. Hormonal replacement therapy reduces forearm fracture incidence in recent postmenopausal women

    Mosekilde, Leif; Beck-Nielsen, H.; Sørensen, O.H.


    OBJECTIVES: To study the fracture reducing potential of hormonal replacement therapy (HRT) in recent postmenopausal women in a primary preventive scenario. METHODS: Prospective controlled comprehensive cohort trial: 2016 healthy women aged 45-58 years, from three to 24 months past last menstrual...... and possibly the total number of fractures in recent postmenopausal women by use of HRT as primary prevention....


    Takeshi Sakata


    Full Text Available Stress fractures of the first rib in athletes are rare. A 14-year-old male, a baseball pitcher who changed from an overhand to a sidearm style, with a stress fracture of the first rib, was reported. Most Stress fractures in the first rib occur at the subclavian groove, between the attachments of the scalenus anterior and scalenus medius muscles, which is the thinnest and weakest portion of the rib. However, in this case the stress fracture occurred at the uncommon region, posterior to the insertion of the scalenus medius muscle, in the first rib. The motion analysis of the pitching in this case demonstrated that the sidearm style induced much more horizontal abduction in the shoulder at the top position than did the overhand style. The findings of electromyography in the serratus anterior muscle, one of the muscles which insert on the first rib, through the pitching motion did not demonstrate any significant differences between the two styles. In this case, the repetition of horizontal over-abduction of the shoulder when sidearm pitching appears to have been the cause of the unusual stress fracture of the first rib at this site

  11. Talar body fatigue stress fractures: three cases observed in elite female gymnasts

    Rossi, F. [National Institute of Sports Medicine of the Italian Olympic Committee, Rome (Italy); Dragoni, S. [National Institute of Sports Medicine of the Italian Olympic Committee, Rome (Italy); Istituto Nazionale di Medicina dello Sport, Rome (Italy)


    To introduce and emphasize the clinical and radiological findings of three talar body fatigue stress fractures in competitive athletes. Clinical and radiographic skeletal records of 24,562 athletes taken between 1962 and 2002 were retrospectively reviewed. Among these, 6851 files related to acute foot and ankle injuries or chronic post-traumatic sequelae were found. There were 925 (3.76%) stress fatigue fractures selected from the whole collection. Among these there were three cases (0.32%) of talar body stress fractures diagnosed in elite female gymnasts 15 - 17 years old. The negative first radiograph become positive 4-6 weeks later. Scintigraphy was positive at an early stage and consistent for the diagnosis. CT and MRI gave positive results 1-2 weeks after the beginning of symptoms which were always greatly diagnostic. The sports medicine literature lacks reports of talar body fatigue stress fractures. The poor initial sensitivity of radiography makes it problematic to establish an early diagnosis. A wise combination of scintigraphy, CT and MRI has therefore to be relied upon. Familiarity with this rare location for a stress fracture may prevent delayed diagnosis and long-lasting damage, both of which are important factors in competitive athletes. (orig.)

  12. Dealing Collectively with Critical Incident Stress Reactions in High Risk Work Environments

    Müller-Leonhardt, Alice; Strøbæk, Pernille Solveig; Vogt, joachim


    aim of this paper is to shift the representation of coping patterns within high risk occupations to an existential part of cultural pattern and social structure, which characterises high reliability organisations. Drawing upon the specific peer model of critical incident stress management (CISM......), in which qualified operational peers support colleagues who experienced critical incident stress, the paper discusses critical incident stress management in air traffic control. Our study revealed coping patterns that co-vary with the culture that the CISM programme fostered within this specific high...... organisations. Indeed, we found that the CISM programme once integrated within the socio-cultural patterns of this specific working environment enhanced not only individual feelings of being supported but also organisational safety culture. Keywords: coping; safety culture; critical incident stress management...

  13. Perceived effectiveness of critical incident stress debriefing by Australian nurses

    O'Connor, J; Jeavons, S


    This paper examines the perceived effectiveness of stress debriefing by a sample of 129 Australian hospital nurses and the relationship of their perceptions to demographic variables such as qualifications and work area...

  14. Impacts of Job Stress and Cognitive Failure on Patient Safety Incidents among Hospital Nurses

    Young-Mi Park


    Conclusion: Patient safety incidents were affected by shift work, cognitive failure, and job stress. Many countermeasures to reduce the incidents caused by shift work, and plans to reduce job stress to reduce the workers' cognitive failure are required. In addition, there is a necessity to reduce job instability and clearly define the scope and authority for duties that are directly related to the patient's safety.

  15. Transferability of Charpy Absorbed Energy to Fracture Toughness Based on Weibull Stress Criterion

    Hongyang JING; Lianyong XU; Lixing HUO; Fumiyoshi Minami


    The relationship between Charpy absorbed energy and the fracture toughness by means of the (crack tip opening displacement (CTOD)) method was analyzed based on the Weibull stress criterion. The Charpy absorbed energy and the fracture toughness were measured for the SN490B steel under the ductile-brittle transition temperature region. For the instrumented Charpy impact test, the curves between the loading point displacement and the load against time were recorded. The critical Weibull stress was taken as a fracture controlled parameter, and it could not be affected by the specimen configuration and the loading pattern based on the local approach. The parameters controlled brittle fracture are obtained from the Charpy absorbed energy results, then the fracture toughness for the compact tension (CT) specimen is predicted. It is found that the results predicted are in good agreement with the experimental. The fracture toughness could be evaluated by the Charpy absorbed energy, because the local approach gives a good description for the brittle fracture even though the Charpy impact specimen or the CT specimen is used for the given material.

  16. Damage and fracture mechanism of 6063 aluminum alloy under three kinds of stress states

    ZHU Hao; ZHU Liang; CHEN Jianhong


    To study the damage and fracture mechanism of 6063 aluminum alloy under different stress states,three kinds of representative triaxial stress states have been adopted,namely smooth tensile,notch tensile,and pure shear.The results of the study indicate the following.During the notch tensile test,a relatively higher stress triaxiality appears in the root of the notch.With the applied loading increasing,the volume fraction of microvoids in the root of the notch increases continuously.When it reaches the critical volume fraction of microvoids,the specimen fractures.During the pure shear test,the stress triaxiality almost equals to zero,and there is almost no microvoids but a shear band at the center of the butterfly specimen.The shear band results from nonuniform deformation constantly under the shear stress.With stress concentration,cracks are produced within the shear band and are later coalesced.When the equivalent plastic strain reaches the critical value (equivalent plastic fracture strain),the butterfly specimen fractures.During the smooth tensile test,the stress triaxiality in the gauge of the specimen remains constant at 0.33.Thus,the volume of microvoids of the smooth tensile test is less than that of the notch tensile test and the smooth specimen fractures due to shearing between microvoids.The G-T-N damage model and Johnson-Cook model are used to simulate the notch tensile and shear test,respectively.The simulated engineering stress-strain curves fit the measured engineering stress-strain curves very well.In addition,the empirical damage evolution equation for the notch specimen is obtained from the experimental data and FEM simulations.

  17. The impact of in-situ stress and outcrop-based fracture geometry on hydraulic aperture and upscaled permeability in fractured reservoirs

    Bisdom, Kevin; Bertotti, Giovanni; Nick, Hamid


    Aperture has a controlling impact on porosity and permeability and is a source of uncertainty in modeling of naturally fractured reservoirs. This uncertainty results from difficulties in accurately quantifying aperture in the subsurface and from a limited fundamental understanding of the mechanical...... explicitly, we quantify equivalent permeability, i.e. combined matrix and stress-dependent fracture flow. Fracture networks extracted from a large outcropping pavement form the basis of these models. The results show that the angle between fracture strike and σ 1 has a controlling impact on aperture...... and permeability, where hydraulic opening is maximum for an angle of 15°. At this angle, the fracture experiences a minor amount of shear displacement that allows the fracture to remain open even when fluid pressure is lower than the local normal stress. Averaging the heterogeneous aperture to scale up...

  18. In-situ stress measurements and stress change monitoring to monitor overburden caving behaviour and hydraulic fracture pre-conditioning

    Puller Jesse W.; Mills Ken W.; Jeffrey Rob G.; Walker Rick J.


    A coal mine in New South Wales is longwall mining 300 m wide panels at a depth of 160–180 m directly below a 16–20 m thick conglomerate strata. As part of a strategy to use hydraulic fracturing to manage potential windblast and periodic caving hazards associated with these conglomerate strata, the in-situ stresses in the conglomerate were measured using ANZI strain cells and the overcoring method of stress relief. Changes in stress associated with abutment loading and placement of hydraulic fractures were also measured using ANZI strain cells installed from the surface and from underground. Overcore stress mea-surements have indicated that the vertical stress is the lowest principal stress so that hydraulic fractures placed ahead of mining form horizontally and so provide effective pre-conditioning to promote caving of the conglomerate strata. Monitoring of stress changes in the overburden strata during longwall retreat was undertaken at two different locations at the mine. The monitoring indicated stress changes were evi-dent 150 m ahead of the longwall face and abutment loading reached a maximum increase of about 7.5 MPa. The stresses ahead of mining change gradually with distance to the approaching longwall and in a direction consistent with the horizontal in-situ stresses. There was no evidence in the stress change monitoring results to indicate significant cyclical forward abutment loading ahead of the face. The for-ward abutment load determined from the stress change monitoring is consistent with the weight of over-burden strata overhanging the goaf indicated by subsidence monitoring.

  19. High incidence of fracture events in patients with Long-Gap Esophageal Atresia (LGEA: A retrospective review prompting implementation of standardized protocol

    Sigrid Bairdain


    Conclusion: Episodes of paralysis appeared to be the most significant risk factor for fractures in patients with LGEA who underwent the Foker procedure. The incidence of symptomatic fractures decreased significantly following implementation of a standardized protocol in this series of LGEA patients with continued prospective evaluation.

  20. Critical incident stress debriefing following the terrorist bombing at Army Headquarters Northern Ireland.

    Finnegan, A P; Cumming, P A; Piper, M E


    On the 7 October 1996 the Provisional Irish Republican Army launched a terrorist attack within Northern Ireland. This paper provides a descriptive reflective account of the psychological support and Critical Incident Stress Debriefings (CISD) provided for civilian/military personnel and service families. Between 66 hours and 96 hours following the incident, 407 people were debriefed.

  1. Adapting Critical Incident Stress Management to the Schools: A Multi-Agency Approach

    Tortorici, Joanne; Johnson, Luna Kendall


    The need for school-appropriate applications of critical incident stress management (CISM) is noted in the literature on school crisis response. This paper presents preliminary data suggesting a School Crisis Response Team's (SCRT) usage and team needs. The SCRT was dispatched for a variety of critical incidents. Self-dispatch, followed by…

  2. Stress fractures of the ribs in elite competitive rowers: a report of nine cases

    Dragoni, S. [Institute of Sport Medicine and Science of the Italian Olympic Committee, Department of Radiology, Rome (Italy); Giombini, A.; Ripani, M. [University of Motor Sciences, Department of Health, Rome (Italy); Di Cesare, A. [University of Rome ' ' La Sapienza' ' , Department of Physical Medicine and Rehabilitation, Rome (Italy); Magliani, G. [Medical Department of the Italian State Police, Rome (Italy)


    The objective was to report the clinical and imaging patterns of nine cases of stress fractures of the rib diagnosed in Italian Olympic rowers. Nine patients with stress fractures of the rib detected from 103 (8.7%) Italian team rowers competing between May 2000 and May 2006 were identified based on the database of a sports medicine institute. All athletes were male. They were aged between 17 and 31 years (mean: 24.4). Patient weight, fracture location, rowing side and imaging methods employed were noted. The diagnosis was made based on history, clinical examination and Tc-99m MDP bone scintigraphy. Eight of the 9 fractures were located anterolaterally between the fourth and ninth rib. In 1 of the 5 athletes with standard radiographs, a fracture line was visible and in 4 there was callus formation. In 2 athletes sonography was performed, which detected discontinuity of the rib surface and callus formation (1 case each). Stress fractures of the ribs are relatively common in competitive rowers. They are characterized by increasing lateral chest pain and typical scintigraphic, radiographic and sonographic findings. (orig.)

  3. Critical incident stress intervention after loss of an air ambulance: two-year follow up.

    Macnab, A J; Russell, J A; Lowe, J P; Gagnon, F


    Following an air ambulance crash with five fatalities, critical incident stress debriefing (CISD) was provided for involved paramedics, physicians, and nurses. A study was conducted to evaluate the long-term effects of a critical incident with critical incident stress debriefing according to the Mitchell model. Six months following the incident, empirically designed questionnaires were mailed to all transport paramedics and directly involved medical staff, and a random sample of both nurses from the dispatch/receiving institution and paramedics from around the province. Twenty-four months post-incident, all members of the transport paramedics completed the Impact of Events Scale and the General Health Questionnaires. There were no differences between groups on any scores, except for disturbed sleep patterns, bad dreams, and the need for personal counseling being greater among transport paramedics at one day. There was no correlation between how well the deceased individuals were known, amount of debriefing, and symptom severity. A trend was seen for those with pre-existing stress management routines to have less severe symptoms at six months (p = 0.07). At two years, 16% of transport paramedics still had significant abnormal behavior. CISD did not appear to affect the severity of stress symptoms, whereas having pre-existing stress management strategies may. These findings give justification for proceeding to a randomized, controlled trial of different levels of critical incident stress intervention.

  4. Effective-stress-law behavior of Austin chalk rocks for deformation and fracture conductivity

    Warpinski, N.R.; Teufel, L.W.


    Austin chalk core has been tested to determine the effective law for deformation of the matrix material and the stress-sensitive conductivity of the natural fractures. For deformation behavior, two samples provided data on the variations of the poroelastic parameter, {alpha}, for Austin chalk, giving values around 0.4. The effective-stress-law behavior of a Saratoga limestone sample was also measured for the purpose of obtaining a comparison with a somewhat more porous carbonate rock. {alpha} for this rock was found to be near 0.9. The low {alpha} for the Austin chalk suggests that stresses in the reservoir, or around the wellbore, will not change much with changes in pore pressure, as the contribution of the fluid pressure is small. Three natural fractures from the Austin chalk were tested, but two of the fractures were very tight and probably do not contribute much to production. The third sample was highly conductive and showed some stress sensitivity with a factor of three reduction in conductivity over a net stress increase of 3000 psi. Natural fractures also showed a propensity for permanent damage when net stressed exceeded about 3000 psi. This damage was irreversible and significantly affected conductivity. {alpha} was difficult to determine and most tests were inconclusive, although the results from one sample suggested that {alpha} was near unity.

  5. Randomized, controlled trial of three levels of critical incident stress intervention.

    Macnab, Andrew; Sun, Charles; Lowe, John


    Stress debriefing following exposure to a critical incident is becoming more prevalent. Its aim is to prevent or minimize the development of excessive stress response symptoms that lead to loss of productivity or effectiveness in the workplace or at home. There is little evidence that any form of psychological debriefing is effective. This study evaluated the effectiveness of three intervention strategies, and attempted to correlate the symptoms with the severity of the incident and level of intervention. A randomized, controlled trial of three levels of critical stress intervention was conducted in the British Columbia Ambulance Service (BCAS), in British Columbia, Canada, among paramedics and emergency medical technicians (EMTs), reporting critical incident stress. Outcomes were measured at one week (Stanford Acute Stress Reaction Questionnaire (SASRQ), the Life Impact Score (LIS), and Schedule of Recent Events (SRE)), and at three months and six months following the intervention (Impact of Events (IE), Coping Mechanisms, LIS, and SRE). Fifty calls were received during the 26-month study period (incident and scores on the SASRQ, IE, or LIS, or between any of these scores. There was no consistent pattern in the stress scores over time. Requests for critical incident stress intervention were uncommon. The need for intervention may not be as great as generally is assumed. Further randomized trials, ideally multicenter studies, are indicated.

  6. Rockfall triggering by cyclic thermal stressing of exfoliation fractures

    Collins, Brian; Stock, Greg M.


    Exfoliation of rock deteriorates cliffs through the formation and subsequent opening of fractures, which in turn can lead to potentially hazardous rockfalls. Although a number of mechanisms are known to trigger rockfalls, many rockfalls occur during periods when likely triggers such as precipitation, seismic activity and freezing conditions are absent. It has been suggested that these enigmatic rockfalls may occur due to solar heating of rock surfaces, which can cause outward expansion. Here we use data from 3.5 years of field monitoring of an exfoliating granite cliff in Yosemite National Park in California, USA, to assess the magnitude and temporal pattern of thermally induced rock deformation. From a thermodynamic analysis, we find that daily, seasonal and annual temperature variations are sufficient to drive cyclic and cumulative opening of fractures. Application of fracture theory suggests that these changes can lead to further fracture propagation and the consequent detachment of rock. Our data indicate that the warmest times of the day and year are particularly conducive to triggering rockfalls, and that cyclic thermal forcing may enhance the efficacy of other, more typical rockfall triggers.

  7. Rockfall triggering by cyclic thermal stressing of exfoliation fractures

    Collins, Brian D.; Stock, Greg M.


    Exfoliation of rock deteriorates cliffs through the formation and subsequent opening of fractures, which in turn can lead to potentially hazardous rockfalls. Although a number of mechanisms are known to trigger rockfalls, many rockfalls occur during periods when likely triggers such as precipitation, seismic activity and freezing conditions are absent. It has been suggested that these enigmatic rockfalls may occur due to solar heating of rock surfaces, which can cause outward expansion. Here we use data from 3.5 years of field monitoring of an exfoliating granite cliff in Yosemite National Park in California, USA, to assess the magnitude and temporal pattern of thermally induced rock deformation. From a thermodynamic analysis, we find that daily, seasonal and annual temperature variations are sufficient to drive cyclic and cumulative opening of fractures. Application of fracture theory suggests that these changes can lead to further fracture propagation and the consequent detachment of rock. Our data indicate that the warmest times of the day and year are particularly conducive to triggering rockfalls, and that cyclic thermal forcing may enhance the efficacy of other, more typical rockfall triggers.

  8. Low back pain during pregnancy caused by a sacral stress fracture: a case report

    Pishnamaz Miguel


    Full Text Available Abstract Introduction Sacral stress fractures are a rare but well known cause of low back pain. This type of fracture has also been observed as a postpartum complication. To date, no cases of intrapartum sacral stress fractures have been described in the literature. Case presentation We report the case of a 26-year-old Caucasian European primigravid patient (30 weeks and two days of gestation who presented to our outpatient clinic with severe low back pain that had started after a downhill walk 14 days previously. She had no history of trauma. A magnetic resonance imaging scan revealed a non-displaced stress fracture of the right lateral mass of her sacrum. Following her decision to opt for non-operative treatment, our patient received an epidural catheter for pain control. The remaining course of her pregnancy was uneventful and our patient gave birth to a healthy child by normal vaginal delivery. Conclusions We conclude that a sacral stress fracture must be considered as a possible cause of low back pain during pregnancy.

  9. A new coal-permeability model: Internal swelling stress and fracture-matrix interaction

    Liu, H.H.; Rutqvist, J.


    We have developed a new coal-permeability model for uniaxial strain and constant confining stress conditions. The model is unique in that it explicitly considers fracture-matrix interaction during coal deformation processes and is based on a newly proposed internal-swelling stress concept. This concept is used to account for the impact of matrix swelling (or shrinkage) on fracture-aperture changes resulting from partial separation of matrix blocks by fractures that do not completely cut through the whole matrix. The proposed permeability model is evaluated with data from three Valencia Canyon coalbed wells in the San Juan Basin, where increased permeability has been observed during CH{sub 4} gas production, as well as with published data from laboratory tests. Model results are generally in good agreement with observed permeability changes. The importance of fracture-matrix interaction in determining coal permeability, demonstrated in this work using relatively simple stress conditions, underscores the need for a dual-continuum (fracture and matrix) mechanical approach to rigorously capture coal-deformation processes under complex stress conditions, as well as the coupled flow and transport processes in coal seams.

  10. Polymorphisms of muscle genes are associated with bone mass and incident osteoporotic fractures in Caucasians

    Harsløf, Torben; Frost, M; Nielsen, T L


    The interaction between muscle and bone is complex. The aim of this study was to investigate if variations in the muscle genes myostatin (MSTN), its receptor (ACVR2B), myogenin (MYOG), and myoD1 (MYOD1) were associated with fracture risk, bone mineral density (BMD), bone mineral content (BMC......-29 years. Nine tag SNPs in the four genes were investigated. In the DOPS, individuals homozygous for the variant allele of the MSTN SNP rs7570532 had an increased risk of any osteoporotic fracture, with an HR of 1.82 (95 % CI 1.15-2.90, p = 0.01), and of nonvertebral osteoporotic fracture, with an HR of 2...... an association between a variant in MSTN and fracture risk and bone loss. Further studies are needed to confirm the findings....

  11. Proximal fibular stress fractures in children and adolescents, what should we rely on? Lessons learned from a case.

    de Pina, Carlos Aguiar Ramos; Balacó, Inês; Serrano, Pedro Ruas; Matos, Gabriel


    Fibula fractures are the third most common stress fractures in children and adolescents. The triad of localised periosteal reaction, endosteal thickening and radiolucent cortical lines, localised in the distal third of the fibula along with a typical clinical history is in most cases sufficient to establish the diagnosis. Proximal fibula stress lesions are a very rare finding, with few reports in the literature. Stress fractures in this location demand careful investigation before a definitive diagnosis can be made. In the presence of non-specific MRI findings, stress fracture should be a diagnosis of exclusion. The authors report a case referred to their department by a sports medicine physician with a suspicion of stress fracture of the proximal fibula without characteristic imaging findings, which was ultimately confirmed as a stress lesion only by biopsy.

  12. Patient-specific finite element analysis of chronic contact stress exposure after intraarticular fracture of the tibial plafond.

    Li, Wendy; Anderson, Donald D; Goldsworthy, Jane K; Marsh, J Lawrence; Brown, Thomas D


    The role of altered contact mechanics in the pathogenesis of posttraumatic osteoarthritis (PTOA) following intraarticular fracture remains poorly understood. One proposed etiology is that residual incongruities lead to altered joint contact stresses that, over time, predispose to PTOA. Prevailing joint contact stresses following surgical fracture reduction were quantified in this study using patient-specific contact finite element (FE) analysis. FE models were created for 11 ankle pairs from tibial plafond fracture patients. Both (reduced) fractured ankles and their intact contralaterals were modeled. A sequence of 13 loading instances was used to simulate the stance phase of gait. Contact stresses were summed across loadings in the simulation, weighted by resident time in the gait cycle. This chronic exposure measure, a metric of degeneration propensity, was then compared between intact and fractured ankle pairs. Intact ankles had lower peak contact stress exposures that were more uniform and centrally located. The series-average peak contact stress elevation for fractured ankles was 38% (p = 0.0015; peak elevation was 82%). Fractured ankles had less area with low contact stress exposure than intact ankles and a greater area with high exposure. Chronic contact stress overexposures (stresses exceeding a damage threshold) ranged from near zero to a high of 18 times the matched intact value. The patient-specific FE models represent substantial progress toward elucidating the relationship between altered contact stresses and the outcome of patients treated for intraarticular fractures.

  13. Risk Stratification of Stress Fractures and Prediction of Return-to-Duty


    Award Number: W81XWH-15-C-0024 TITLE: Risk Stratification of Stress Fractures and Prediction of Return -to-Duty PRINCIPAL INVESTIGATOR: Mary L...SUBTITLE Risk Stratification of Stress Fractures and Prediction of Return -to-Duty 5a. CONTRACT NUMBER W81XWH-15-C-0024 Return -to-Duty 5b. GRANT... RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE December 2016 2. REPORT TYPE Annual 3. DATES COVERED 15 Nov 2015- 14 Nov 2016 4. TITLE AND

  14. Critical incident stress debriefing: keeping your flight crew healthy.

    Troiani, T A; Boland, R T


    Most flight team members have experienced some type of a stress reaction in their flight career, but few have been debriefed appropriately. Debriefings are necessary to keep flight personnel mentally healthy. Fatal crashes have always drawn attention, and some teams have been debriefed afterward. Proper debriefing and formal mental health evaluation may be the answer.

  15. A Critical-Incident Stress Debriefing Program for Hospital-Based Health Care Personnel.

    Spitzer, William J.; Burke, Laurie


    Reviews individual and institutional effects of critical-incident stress on health care delivery and use of stress education, defusings, and debriefings as effective interventions with health care personnel. Presents successful efforts of social work department using these techniques in major university hospital system as model for replication in…

  16. Declining incidence trends for hip fractures have not been accompanied by improvements in lifetime risk or post-fracture survival--A nationwide study of the Swedish population 60 years and older.

    Karampampa, Korinna; Ahlbom, Anders; Michaëlsson, Karl; Andersson, Tomas; Drefahl, Sven; Modig, Karin


    Hip fracture is a common cause of disability and mortality among the elderly. Declining incidence trends have been observed in Sweden. Still, this condition remains a significant public health problem since Sweden has one of the highest incidences worldwide. Yet, no Swedish lifetime risk or survival trends have been presented. By examining how hip fracture incidence, post-fracture survival, as well as lifetime risk have developed between 1995 and 2010 in Sweden, this study aims to establish how the burden hip fractures pose on the elderly changed over time, in order to inform initiatives for improvements of their health. The entire Swedish population 60 years-old and above was followed between 1987 and 2010 in the National Patient Register and the Cause of Death Register. Annual age-specific hip fracture cumulative incidence was estimated using hospital admissions for hip fractures. Three-month and one-year survival after the first hip fracture were also estimated. Period life table was used to assess lifetime risk of hip fractures occurring from age 60 and above, and the expected mean age of the first hip fracture. The age-specific hip fracture incidence decreased between 1995 and 2010 in all ages up to 94 years, on average by 1% per year. The lifetime risk remained almost stable, between 9% and 11% for men, and between 18% and 20% for women. The expected mean age of a first hip fracture increased by 2.5 years for men and by 2.2 years for women. No improvements over time were observed for the 3-month survival for men, while for women a 1% decrease per year was observed. The 1-year survival slightly increased over time for men (0.4% per year) while no improvement was observed for women. The age-specific hip fracture incidence has decreased over time. Yet the lifetime risk of a hip fracture has not decreased because life expectancy in the population has increased in parallel. Overall, survival after hip fracture has not improved. Copyright © 2015. Published by

  17. Ten-year incidence and risk factors of bone fractures in a cohort of treated HIV1-infected adults

    Collin, Fidéline; Duval, Xavier; Lemoing, Vincent; Piroth, Lionel; Al Kaied, Firas; Massip, Patrice; Villes, Virginie; Chêne, Geneviève; Raffi, François


    In the ANRS CO8 APROCO-COPILOTE cohort of patients treated with combination antiretroviral therapy since 1997–1999, the incidence density of bone fractures was 3.3 for 1,000 patient-years (95% CI: 2.0–4.6). Rate was 2.9-fold (95% CI: 1.3–6.5) higher among patients with excessive alcohol consumption and 3.6-fold (95% CI: 1.6–8.1) higher in those with Hepatitis C virus (HCV) co-infection. Specific monitoring of HCV/HIV-coinfected patients and active promotion of alcohol cessation should be recommended for the prevention of bone fractures. PMID:19300202

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

    Bisdom, Kevin; Bertotti, Giovanni; Nick, Hamidreza M.


    Predicting equivalent permeability in fractured reservoirs requires an understanding of the fracture network geometry and apertures. There are different methods for defining aperture, based on outcrop observations (power law scaling), fundamental mechanics (sublinear length-aperture scaling), and experiments (Barton-Bandis conductive shearing). Each method predicts heterogeneous apertures, even along single fractures (i.e., intrafracture variations), but most fractured reservoir models imply constant apertures for single fractures. We compare the relative differences in aperture and permeability predicted by three aperture methods, where permeability is modeled in explicit fracture networks with coupled fracture-matrix flow. Aperture varies along single fractures, and geomechanical relations are used to identify which fractures are critically stressed. The aperture models are applied to real-world large-scale fracture networks. (Sub)linear length scaling predicts the largest average aperture and equivalent permeability. Barton-Bandis aperture is smaller, predicting on average a sixfold increase compared to matrix permeability. Application of critical stress criteria results in a decrease in the fraction of open fractures. For the applied stress conditions, Coulomb predicts that 50% of the network is critically stressed, compared to 80% for Barton-Bandis peak shear. The impact of the fracture network on equivalent permeability depends on the matrix hydraulic properties, as in a low-permeable matrix, intrafracture connectivity, i.e., the opening along a single fracture, controls equivalent permeability, whereas for a more permeable matrix, absolute apertures have a larger impact. Quantification of fracture flow regimes using only the ratio of fracture versus matrix permeability is insufficient, as these regimes also depend on aperture variations within fractures.

  19. Critical incident stress debriefing for law enforcement: practical models and special applications.

    Miller, Laurence


    Critical incident stress debriefing (CISD) has evolved and diversified to address the needs of various subpopulations of public safety and emergency services personnel, including law enforcement. This article describes the concept of critical incident stress as it applies to police officers and other law enforcement agents. It then discusses the traditional debriefing models and the specialized modifications and applications that have been introduced to deal with the needs of law enforcement individuals and groups. Next, the role of peer-debriefing is described in addressing law enforcement critical incident stress, as well as specific examples of model programs within different types of law enforcement agencies. Finally, the as yet incompletely resolved legal and administrative issues surrounding the use of peers versus professional clinicians for critical incident intervention are addressed.

  20. Acoustic Emission Based Surveillance System for Prediction of Stress Fractures


    aging are susceptible to such fractures in contexts of osteoporosis, diabetes, cerebral palsy , fibrous dysplasia and osteogenesis imperfecta. This...until the specimen failed. The test machine recorded the load and displacement data from the load cell and machine actuator displacement, and a second...and eliminated extraneous events which stem from activities other than the formation of microdamage. • Conducted three-point bending tests on

  1. Do Capacity Coupled Electric Fields Accelerate Tibial Stress Fracture Healing


    MJ, Goll SR, Nichols CE, 3rd, Pollack SR: Prevention and treatment of sciatic denervation disuse osteoporosis in the rat tibia with capacitively...the healing of fractures. J Bone Joint Surg Am 83-A:259-70, 2001 40. Rubin CT, McLeod KJ, Lanyon LE: Prevention of osteoporosis by pulsed...USA Corresponding author Belinda R. Beck, Ph.D. Griffith University School of Physiotherapy and Exercise Science, PMB 50 Gold Coast Mail Centre Q

  2. Perceived Stress and Colorectal Cancer Incidence: The Japan Collaborative Cohort Study

    Kikuchi, Norimasa; Nishiyama, Takeshi; Sawada, Takayuki; Wang, Chaochen; Lin, Yingsong; Watanabe, Yoshiyuki; Tamakoshi, Akiko; Kikuchi, Shogo


    Colorectal cancer is the third most common cancer worldwide, and many risk factors for colorectal cancer have been established. However, it remains uncertain whether psychological stress contributes to the onset of colorectal cancer. Therefore, we conducted a large-scale prospective cohort study to confirm the association between perceived stress and colorectal cancer incidence. We identified 680 cases of colon cancer and 330 cases of rectal cancer during a maximum of 21-year follow-up of 61,563 Japanese men and women. Cox regression analysis adjusted for potential confounders revealed a significant association of perceived stress with rectal cancer incidence but not with colon cancer incidence. This finding is partly consistent with that from only one previous study that addressed an association between perceived stress and the risk of colorectal cancer. However, studies on this topic are sparse and warrant further exploration. PMID:28091607

  3. Stronger back muscles reduce the incidence of vertebral fractures: a prospective 10 year follow-up of postmenopausal women.

    Sinaki, M; Itoi, E; Wahner, H W; Wollan, P; Gelzcer, R; Mullan, B P; Collins, D A; Hodgson, S F


    The long-term protective effect of stronger back muscles on the spine was determined in 50 healthy white postmenopausal women, aged 58-75 years, 8 years after they had completed a 2 year randomized, controlled trial. Twenty-seven subjects had performed progressive, resistive back-strengthening exercises for 2 years and 23 had served as controls. Bone mineral density, spine radiographs, back extensor strength, biochemical marker values, and level of physical activity were obtained for all subjects at baseline, 2 years, and 10 years. Mean back extensor strength (BES) in the back-exercise (BE) group was 39.4 kg at baseline, 66.8 kg at 2 years (after 2 years of prescribed exercises), and 32.9 kg at 10 years (8 years after cessation of the prescribed exercises). Mean BES in the control (C) group was 36.9 kg at baseline, 49.0 kg at 2 years, and 26.9 kg at 10 years. The difference between the two groups was still statistically significant at 10 year follow-up (p = 0.001). The difference in bone mineral density, which was not significant between the two groups at baseline and 2 year follow-up, was significant at 10 year follow-up (p = 0.0004). The incidence of vertebral compression fracture was 14 fractures in 322 vertebral bodies examined (4.3%) in the C group and 6 fractures in 378 vertebral bodies examined (1.6%) in the BE group (chi-square test, p = 0.0290). The relative risk for compression fracture was 2.7 times greater in the C group than in the BE group. To our knowledge, this is the first study reported in the literature demonstrating the long-term effect of strong back muscles on the reduction of vertebral fractures in estrogen-deficient women.

  4. Unilateral Pedicle Stress Fracture in a Long-Term Hemodialysis Patient with Isthmic Spondylolisthesis

    Keishi Maruo


    Full Text Available Most unilateral pedicle stress fractures occur on the contralateral side of patients with unilateral spondylolysis. However, there are few reports of unilateral pedicle stress fractures in patients with bilateral spondylolysis and spondylolisthesis. We report a unique case of unilateral pedicle stress fracture in a long-term hemodialysis patient with isthmic spondylolisthesis. A 65-year-old man who had undergone hemodialysis presented with lower back pain that had persisted for several years. The patient experienced severe right lower extremity pain with no history of trauma. Computed tomography revealed unilateral pedicle fracture with bilateral L5 spondylolysis and spondylolisthesis with progression of scoliosis. The patient underwent Gill laminectomy of L5 with pedicle screw fixation at L4-S1 and interbody fusion at L5-S1. The patient’s leg pain ceased immediately, and he began walking without leg pain. In our present patient, development of scoliosis caused by destructive spondyloarthropathy may have contributed to a unilateral pedicle fracture.

  5. Extremely Low-Stress Triaxiality Tests in Calibration of Fracture Models in Metal-Cutting Simulation

    Šebek, František; Kubík, Petr; Petruška, Jindřich; Hůlka, Jiří


    The cutting process is now combined with machining, milling, or drilling as one of the widespread manufacturing operations. It is used across various fields of engineering. From an economical point of view, it is desirable to maintain the process in the most effective way in terms of the fracture surface quality or minimizing the burr. It is not possible to manage this experimentally in mass production. Therefore, it is convenient to use numerical computation. To include the crack initiation and propagation in the computations, it is necessary to implement a suitable ductile fracture criterion. Uncoupled ductile fracture models need to be calibrated first from fracture tests when the test selection is crucial. In the present article, there were selected widespread uncoupled ductile fracture models calibrated with, among others, an extremely low-stress triaxiality test realized through the compression of a cylinder with a specific recess. The whole experimental program together with the cutting process experiment were carried out on AISI 1045 carbon steel. After the fracture models were calibrated and the cutting process was simulated with their use, fracture surfaces and force responses from computations were compared with those experimentally obtained and concluding remarks were made.

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

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


    The increase in proportional loading of the fibula with progression of hindfoot deformity would lead to high fibular loads during rapid walking, resulting in insufficiency fractures. We report an unusual mechanism of such fracture in a textile worker resulting from valgus alignment from a stage III flatfoot deformity. The stress fracture was missed initially and only confirmed by CT examination. The patient responded well to nonoperative treatment and had an excellent recovery with no residual symptoms finally. Fracture of the distal fibula caused by rigid hindfoot valgus in stage III flatfoot deformity is a previously undescribed injury. We report a patient who presented with this injury, the possible mechanisms of such injury, its management and outcome. PMID:26131245

  7. Rib stress fractures among rowers: definition, epidemiology, mechanisms, risk factors and effectiveness of injury prevention strategies.

    McDonnell, Lisa K; Hume, Patria A; Nolte, Volker


    Rib stress fractures (RSFs) can have serious effects on rowing training and performance and accordingly represent an important topic for sports medicine practitioners. Therefore, the aim of this review is to outline the definition, epidemiology, mechanisms, intrinsic and extrinsic risk factors, injury management and injury prevention strategies for RSF in rowers. To this end, nine relevant books, 140 journal articles, the proceedings of five conferences and two unpublished presentations were reviewed after searches of electronic databases using the keywords 'rowing', 'rib', 'stress fracture', 'injury', 'mechanics' and 'kinetics'. The review showed that RSF is an incomplete fracture occurring from an imbalance between the rate of bone resorption and the rate of bone formation. RSF occurs in 8.1-16.4% of elite rowers, 2% of university rowers and 1% of junior elite rowers. Approximately 86% of rowing RSF cases with known locations occur in ribs four to eight, mostly along the anterolateral/lateral rib cage. Elite rowers are more likely to experience RSF than nonelite rowers. Injury occurrence is equal among sweep rowers and scullers, but the regional location of the injury differs. The mechanism of injury is multifactorial with numerous intrinsic and extrinsic risk factors contributing. Posterior-directed resultant forces arising from the forward directed force vector through the arms to the oar handle in combination with the force vector induced by the scapula retractors during mid-drive, or repetitive stress from the external obliques and rectus abdominis in the 'finish' position, may be responsible for RSF. Joint hypomobility, vertebral malalignment or low bone mineral density may be associated with RSF. Case studies have shown increased risk associated with amenorrhoea, low bone density or poor technique, in combination with increases in training volume. Training volume alone may have less effect on injury than other factors. Large differences in seat and handle

  8. Simulating the hydraulic stimulation of multiple fractures in an anisotropic stress field applying the discrete element method

    Zeeb, Conny; Frühwirt, Thomas; Konietzky, Heinz


    Key to a successful exploitation of deep geothermal reservoirs in a petrothermal environment is the hydraulic stimulation of the host rock to increase permeability. The presented research investigates the fracture propagation and interaction during hydraulic stimulation of multiple fractures in a highly anisotropic stress field. The presented work was conducted within the framework of the OPTIRISS project, which is a cooperation of industry partners and universities in Thuringia and Saxony (Federal States of Germany) and was funded by the European Fond for Regional Development. One objective was the design optimization of the subsurface geothermal heat exchanger (SGHE) by means of numerical simulations. The presented simulations were conducted applying 3DEC (Itasca™), a software tool based on the discrete element method. The simulation results indicate that the main direction of fracture propagation is towards lower stresses and thus towards the biosphere. Therefore, barriers might be necessary to limit fracture propagation to the designated geological formation. Moreover, the hydraulic stimulation significantly alters the stresses in the vicinity of newly created fractures. Especially the change of the minimum stress component affects the hydraulic stimulation of subsequent fractures, which are deflected away from the previously stimulated fractures. This fracture deflection can render it impossible to connect all fractures with a second borehole for the later production. The results of continuative simulations indicate that a fracture deflection cannot be avoided completely. Therefore, the stage alignment was modified to minimize fracture deflection by varying (1) the pauses between stages, (2) the spacing's between adjacent stages, and (3) the angle between stimulation borehole and minimum stress component. An optimum SGHE design, which implies that all stimulated fractures are connected to the production borehole, can be achieved by aligning the stimulation

  9. Incidence and risk factors for hip or other bone fractures among hemodialysis patients in the Dialysis Outcomes and Practice Patterns Study.

    Jadoul, M; Albert, J M; Akiba, T; Akizawa, T; Arab, L; Bragg-Gresham, J L; Mason, N; Prutz, K-G; Young, E W; Pisoni, R L


    The available data on bone fractures in hemodialysis (HD) patients are limited to results of a few studies of subgroups of patients in the United States. This study describes the prevalence of hip fractures and the incidence and risk factors associated with hip and other fractures in representative groups of HD facilities (n=320) and patients (n=12 782) from the 12 countries in the second phase of the Dialysis Outcomes and Practice Patterns Study (2002-2004). Among prevalent patients, 2.6% had a prior hip fracture. The incidence of fractures was 8.9 per 1000 patient years for new hip fractures and 25.6 per 1000 for any new fracture. Older age (relative risk (RR)(HIP)=1.91, RR(ANY)=1.33, Pfractures. Elevated risk of new hip fracture was observed for selective serotonin reuptake inhibitors and combination narcotic medications (RR=1.63, RR=1.74, respectively, Pfracture: narcotic pain medications (RR=1.67, P=0.02), benzodiazepines (RR=1.31, P=0.03), adrenal cortical steroids (RR=1.40, P900 pg/ml were associated with an elevated risk of any new fracture (RR=1.72, Pfractures in HD patients.

  10. The inclusion of weld residual stress in fracture margin assessments of embrittled nuclear reactor pressure vessels

    Dickson, T.L.; Bass, B.R.; McAfee, W.J.


    Analyses were performed to determine the impact of weld residual stresses in a reactor pressure vessel (RPV) on (1) the generation of pressure temperature (P-T) curves required for maintaining specified fracture prevention margins during nuclear plant startup and shutdown, and (2) the conditional probability of vessel failure due to pressurized thermal shock (PTS) loading. The through wall residual stress distribution in an axially oriented weld was derived using measurements taken from a shell segment of a canceled RPV and finite element thermal stress analyses. The P-T curve derived from the best estimate load analysis and a t / 8 deep flaw, based on K{sub Ic}, was less limiting than the one derived from the current methodology prescribed in the ASME Boiler and Pressure Vessel Code. The inclusion of the weld residual stresses increased the conditional probability of cleavage fracture due to PTS loading by a factor ranging from 2 to 4.

  11. Facebook, stress, and incidence of upper respiratory infection in undergraduate college students.

    Campisi, Jay; Bynog, Pamela; McGehee, Hope; Oakland, Joshua C; Quirk, Shannon; Taga, Carlee; Taylor, Morgan


    Having a large social network is generally beneficial to health. However, it is unclear how Internet-based social networks might influence health. Chronic stress can have negative health consequences, and some data suggest that Facebook could be a new source of psychological stress. Thus, we examined undergraduate college student perceptions of Facebook use and incidence of upper respiratory infections (URIs). We hypothesized that subjects with more diverse networks (i.e., more friends on Facebook) would have fewer URIs than their less diverse counterparts; that subjects reporting Facebook-induced stress would be more susceptible to URIs; and that subjects with more diverse networks who report Facebook-induced stress would be less susceptible to URIs than subjects with less diverse social networks who reported Facebook-induced stress. In this prospective study, healthy college students completed online questionnaires that assessed use and perceptions of Facebook and technology, and then were interviewed weekly for 10 weeks to track incidence of URI. URI episodes were defined by a symptom-based criterion. The social network size was significantly related to the rate of URI, such that, the larger the social network, the greater the incidence rate of URI. Most (85.7 percent) respondents experienced some degree of Facebook-induced stress. The effects of Facebook-induced stress on incidence of URI varied across the social network size, such that, the impact of stress on the URI incidence rate increased with the size of the social network. These results are largely in contrast to our hypotheses, but clearly suggest an association between Facebook use, psychological stress, and health.

  12. Stresses and Shear Fracture Zone of Jinshazhou Tunnel Surrounding Rock in Rich Water Region

    ZHENG Jun-jie; LOU Xiao-ming


    Field evidence has shown that large-scale and unstable discontinuous planes in the rock mass surrounding tunnels in rich water region are probably generated after excavation. The tunnel surrounding rock was divided into three zones, including elastic zone, plastic damage zone and shear fracture zone fof assessing the stability of the tunnel surrounding rock. By local hydrogeology, the stresses of surrounding rock of Jinshazhou circular tunnel was analyzed and the stress solutions on the elastic and plastic damage zones were obtained by applying the theories of fluid-solid coupling and elasto-plastic damage mechanics. The shear fracture zone generated by joints was studied and its range was determined by using Mohr-Coulomb strength criterion. Finally, the correctness of the theoretical results was validated by comparing the scopes of shear fracture zones calculated in this paper with those from literature.

  13. High incidence of osteoporosis and fractures in an aging post-polio population.

    Mohammad, Ausaf F


    Since the polio epidemic in Ireland in the 1950s, most polio survivors are approaching into the 6th and 7th decade of their lives. There is little data about bone density and risk of fractures in these patients. In 2006, we undertook an audit of post-polio patients attending rheumatology and neurology outpatient clinics in a university teaching hospital. Our aim was to determine the prevalence of osteoporosis (OP), falls and fractures and to evaluate the association of bone density with other potential contributing factors to OP.

  14. Prevention of brittle fracture of steel structures by controlling the local stress and strain fields

    Moyseychik Evgeniy Alekseevich

    Full Text Available In the article the author offers a classification of the methods to increase the cold resistance of steel structural shapes with a focus on the regulation of local fields of internal stresses and strains to prevent brittle fracture of steel structures. The need of a computer thermography is highlighted not only for visualization of temperature fields on the surface, but also to control the fields of residual stresses and strains in a controlled element.

  15. The Relationship of Stressors and Stress on Injury Incident of Construction Workers in Penang

    Muhd Ali Khairul Ammar


    Full Text Available Construction Workers (CWs are the main source of manpower that is necessary to every construction project. Non conducive and hazardous working environment at construction site will affect the physiological health of the construction labour. This study is conducted to explore the impact of job stress and emotional stress to the CWs that potentially lead to injuries incident in Penang. Twelve stressors were identified through factor analysis. Then, the stressors are classified into five main categories. Questionnaires were developed according to the stressstressor relationship. The correlation between factors of injury incident (stressor and stress shows that lack of autonomy and inappropriate safety equipment lead to the emotional stress among the CWs with 0.287 and 0.204 respectively. In addition, poor physical environment causes the job stress among CWs with the correlation of 0.270.

  16. A case of stress fracture of the femoral neck; Przypadek przeciazeniowego zlamania szyjki kosci udowej

    Walenczak, K.; Widawski, T. [Szpital MSW, Lodz (Poland)


    A case of 28 years-old male with stress fracture of the femoral neck is presented. Heterogeneous clinical picture is blamed for diagnostic problems in the initial stage of the disease. Bone scintigraphy aids in the early diagnosis. The use of low frequency electromagnetic field had unquestionable effect on shortening of the treatment time in the case reported. (author). 10 refs, 1 fig.

  17. Relationship between fracturing nominal stress and porosity for metal foams under biaxial tension

    LIU; Peisheng; (刘培生)


    The relationship between two fracturing nominal stresses and porosity has been put forward for metal foams under biaxial tensile loading, and its mathematical formula is proved to be quite practical with the relative experimental data of the metal foam, which is obtained by electrodeposition method.

  18. Misdiagnosis of sacral stress fracture: an underestimated cause of low back pain in pregnancy?

    Deschamps Perdomo, Ambar; Tome-Bermejo, Felix; Piñera, Angel R; Alvarez, Luis


    Sacral stress fracture during pregnancy is an uncommon condition with unclear pathophysiology, presenting with non-specific symptoms and clinical findings. To date, few cases have been published in the literature describing the occurrence of sacral stress fracture during pregnancy. We report a 28-year-old primigravid patient who developed lumbosacral pain at the end of the second trimester. Symptoms were overlooked throughout pregnancy and the postpartum period, resulting in the development of secondary chronic gait and balance problems. Stress fracture of the sacrum should be included in the differential diagnosis of low back and sacral pain during pregnancy. Its prevalence is probably underestimated because of the lack of specificity of the symptoms. Plain radiographs are not appropriate due to radiation exclusion; magnetic resonance is the only method that can be applied safely. There is limited information on natural history but many patients are expected to have a benign course. However, misdiagnosis may lead to prolonged morbidity and the development of secondary gait abnormalities. Stress fracture of the sacrum should be included in the differential diagnosis of low back and sacral pain during pregnancy. A high index of suspicion is necessary to establish an early diagnosis and appropriate treatment.

  19. Residual stress state in pipe cut ring specimens for fracture toughness testing

    Damjanovic, Darko [J.J. Strossmayer Univ. of Osijek, Slavonski Brod (Croatia). Mechanical Engineering Faculty; Kozak, Drazan [Zagreb Univ. (Croatia). Dept. for Mechanical Design; Marsoner, Stefan [Materials Center, Leoben (Austria).; Gubeljak, Nenad [Maribor Univ. (Slovenia). Chair of Mechanics


    Thin-walled pipes are not suitable for measuring fracture toughness parameters of vital importance because longitudinal crack failure is the most common failure mode in pipes. This is due to the impossibility to manufacture standard specimens for measuring fracture toughness, such as SENB or CT specimens, from the thin wall of the pipe. Previous works noticed this problem, but until now, a good and convenient solution has not been found or developed. To overcome this problem, very good alternative solution was proposed, the so-called pipe ring notched bend specimen (PRNB) [1-5]. Until now, only the idealized geometry PRNB specimen is analyzed, i. e., a specimen which is not cut out from an actual pipe but produced from steel plate. Based on that, residual stresses are neglected along with the imperfections in geometry (elliptical and eccentricity). The aim of this research is to estimate the residual stress state(s) in real pipes used in the boiler industry produced by hot rolling technique. These types of pipes are delivered only in normalized condition, but not stress relieved. Therefore, there are residual stresses present due to the manufacturing technique, but also due to uneven cooling after the production process. Within this paper, residual stresses are estimated by three methods: the incremental hole drilling method (IHMD), X-ray diffraction (XRD) and the splitting method (SM). Knowing the residual stress state in the ring specimen, it is possible to assess their impact on fracture toughness measured on the corresponding PRNB specimen(s).

  20. Surgical stabilization of severe rib fractures decreases incidence of retained hemothorax and empyema.

    Majercik, Sarah; Vijayakumar, Sathya; Olsen, Griffin; Wilson, Emily; Gardner, Scott; Granger, Steven R; Van Boerum, Don H; White, Thomas W


    Retained hemothorax (RH) is relatively common after chest trauma and can lead to empyema. We hypothesized that patients who have surgical fixation of rib fractures (SSRF) have less RH and empyema than those who have medical management of rib fractures (MMRF). Admitted rib fracture patients from January 2009 to June 2013 were identified. A 2:1 propensity score model identified MMRF patients who were similar to SSRF. RH, and empyema and readmissions, were recorded. Variables were compared using Fisher exact test and Wilcoxon rank-sum tests. One hundred thirty-seven SSRF and 274 MMRF were analyzed; 31 (7.5%) had RH requiring 35 interventions; 3 (2.2%) SSRF patients had RH compared with 28 (10.2%) MMRF (P = .003). Four (14.3%) MMRF subjects with RH developed empyema versus zero in the SSRF group (P = .008); 6 (19.3%) RH patients required readmission versus 14 (3.7%) in the non-RH group (P = .002). Patients with rib fractures who have SSRF have less RH compared with similar MMRF patients. Although not a singular reason to perform SSRF, this clinical benefit should not be overlooked. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Use of non-fault fractures in stress tensor reconstruction using the Mohr Circle with the Win-tensor program

    Delvaux, Damien


    Paleostress inversion of geological fault-slip data is usually done using the directional part of the applied stress tensor on a slip plane and comparing it with the observed slip lines. However, this method do not fully exploit the brittle data sets as those are composed of shear and tension fractures, in addition to faults. Brittle deformation can be decomposed in two steps. An initial fracture/failure in previously intact rock generate extension/tensile fractures or shear fractures, both without visible opening or displacement. This first step may or not be followed by fracture opening to form tension joints, frictional shearing to form shear faults, or a combination of opening and shearing which produces hybrid fractures. Fractured rock outcrop contain information of the stress conditions that acted during both brittle deformation steps. The purpose here is to investigate how the fracture pattern generated during the initial fracture/failure step might be used in paleostress reconstruction. Each fracture is represented on the Mohr Circle by its resolved normal and shear stress magnitudes. We consider the typical domains on the Mohr circle where the different types de fractures nucleate (tension, hybrid, shear and compression fractures), as well the domain which contain reactivated fractures (faults reactivating an initial fracture plane). In function of the fracture type defined in the field, a "distance" is computed on the Mohr circle between each point and its expected corresponding nucleation/reactivation domain. This "Mohr Distance" is then used as function to minimize during the inversion. We implemented this new function in the Win-Tensor program, and tested it with natural and synthetic data sets from different stress regimes. It can be used alone using only the Mohr Distance on each plane (function F10), or combined with the angular misfit between observed striae and resolved shear directions (composite function F11). When used alone (F10), only the 3

  2. Evaluation of a simplified hip structure analysis method for the prediction of incident hip fracture events.

    Khoo, B C C; Lewis, J R; Brown, K; Prince, R L


    Many attempts have been made to improve the predictive ability of areal bone mineral density (aBMD) which integrates bone mass and area. The addition of an extra variable derived from the hip dual-energy X-ray (DXA) image TR_σ, which describes distribution of mass within the scanned area of the trochanter, improved prediction of 15-year hip fracture probability in elderly women. Two-dimensional DXA imaging of the proximal femur to produce an aBMD is a clinically useful predictor of future fracture risk. Further analysis of the DXA image to produce an eight-variable hip structure analysis (Beck HSA) has been developed to improve understanding of structural factors determining hip bone strength at each of three proximal femur sites, the narrow femoral neck (NN), intertrochanter (TR) and shaft (S). Recently, data on four measurements derived from the currently used eight Beck HSA variables were used to capture population variation in bone structure at each site. These include two previously used variables, the localised aBMD and the sub-periosteal width (W) applying to 5-mm sections (at each sites), and two new variables, standard deviation of normalised mineral-mass projection profile distribution (σ), and displacement between centre-of-mineral mass and geometric centre-of-mineral mass of projection profile (δ). Using a cohort of 1159 women, mean baseline age 75, who sustained 139 hip fractures over 15 years, we determined whether these measures significantly improved 15-year hip fracture prediction compared to current approach utilising age and total hip aBMD. To describe the most parsimonious model for hip fracture risk prediction, the 12 base measures (4 from each site), total hip aBMD and age were evaluated in stepwise logistic regression models. The final model included TR_σ, total hip aBMD and age and provided improved utility for hip fracture prediction compared to total hip aBMD and age alone (C-statistic 0.73 vs. 0.69, P = 0.009 and net

  3. The effects of critical incident stress debriefing (CISD) on emergency medical services personnel following the Los Angeles Civil Disturbance.

    Wee, D F; Mills, D M; Koehler, G


    This study examined the effects of Critical Incident Stress Debriefing (CISD) upon technicians who provided emergency medical services in South Central Los Angeles during the 1992 Los Angeles Civil Disturbance. The relationships between exposure, debriefing and symptoms of stress were identified and examined. The Frederick Reaction Index-Adult (FRI-A) was used to measure the presence of symptoms characteristic of posttraumatic stress disorder. EMTs who had the opportunity to participate in Critical Incident Stress Debriefings (n = 42) following the incident reported fewer symptoms and scored significantly lower on the FRI-A than those not participating in Critical Incident Stress Debriefing (n = 23).

  4. Displacement and stress fields around rock fractures opened by irregular overpressure variations

    Shigekazu eKusumoto


    Full Text Available Many rock fractures are entirely driven open by fluids such as ground water, geothermal water, gas, oil, and magma. These are a subset of extension fractures (mode I cracks; e.g., dikes, mineral veins and joints referred to as hydrofractures. Field measurements show that many hydrofractures have great variations in aperture. However, most analytical solutions for fracture displacement and stress fields assume the loading to be either constant or with a linear variation. While these solutions have been widely used, it is clear that a fracture hosted by heterogeneous and anisotropic rock is normally subject to loading that is neither constant nor with a linear variation. Here we present new general solutions for the displacement and stress fields around hydrofractures, modelled as two-dimensional elastic cracks, opened by irregular overpressure variations given by the Fourier cosine series. Each solution has two terms. The first term gives the displacement and stress fields due to the average overpressure acting inside the crack; it is given by the initial term of the Fourier coefficients expressing the overpressure variation. The second term gives the displacement and stress fields caused by the overpressure variation; it is given by general terms of the Fourier coefficients and solved through numerical integration. Our numerical examples show that the crack aperture variation closely reflects the overpressure variation. Also, that the general displacement and stress fields close to the crack follow the overpressure variation but tend to be more uniform far from the crack. The present solutions can be used to estimate the displacement and stress fields around any fluid-driven crack, that is, any hydrofracture, as well as its aperture, provided the variation in overpressure can be described by Fourier series. The solutions add to our understanding of local stresses, displacements, and fluid transport associated with hydrofractures in the crust.

  5. Bilateral stress fractures of femoral neck in non-athletes:a report of four cases

    Monappa A Naik; Premjit Sujir; Sujit Kumar Tripathy; Sandeep Vijayan; Shamsi Hameed; Sharath K Rao


    Femoral neck stress fractures (FNSFs) are rare,constituting only 5% of all stress fractures in young adults.These fractures are usually seen in athletes,military recruits and patients with underlying metabolic diseases.The treatment of FNSFs is still controversial because of the inherent complications associated with the treatment procedure.We came across 4 cases of bilateral FNSFs in non-athletic individuals who were manual labourers without underlying bony disorders.Two patients with FNSFs and coxa vara deformity on both sides were managed by subtrochanteric valgus osteotomy and dynamic hip screw fixation.One of the remaining two patients was treated by cannulated cancellous screw fixation on one side and subtrochanteric valgus osteotomy on the other side.The fourth patient received subtrochanteric valgus osteotomy on one side and bipolar hemiarthroplasty on the other side after failed cannulated screw fixation.All the fractures healed without any complications.No evidence of avascular necrosis or arthritis was noted in our series.Subtrochanteric valgus osteotomy restores normal neck-shaft angle in patients suffering from FNSFs combined with coxa vara deformity.Moreover,it helps to bring the forces acting around the hip to normal biomechanical levels,leading to fracture union and better results.Replacement arthroplasty is recommended to patients who fail to achieve bony union after fixation.

  6. The influence of elastic modulus of inlay materials on stress distribution and fracture of premolars.

    Costa, Akf; Xavier, Ta; Noritomi, Py; Saavedra, G; Borges, Als


    SUMMARY The purpose of this study was to evaluate the influence the width of the occlusal isthmus and inlay material had on the stress distribution, displacement, and fracture resistance of upper human premolars. For this in vitro test, 35 intact upper premolars (UPM) were selected and five were kept intact for the control group (group I). The remaining 30 were divided into two experimental groups (n=15) according to the width of isthmus: conservative (CP) and extensive preparation (EP), one third and more than two thirds of cuspal distance, respectively. Five teeth from each experimental group were left without restoration for negative controls (CPnc and EPnc), and the remaining 10 in each group were subdivided according to the inlay material (resin or ceramic): group CPr, CP + indirect resin; group CPc, CP + ceramic; group EPr, EP + indirect resin; and group EPc, EP + ceramic. The cemented inlays were loaded in a universal testing machine at a crosshead speed of 0.5 mm/min until fracture. The fractured specimens were analyzed with stereomicroscopy, and the values of the fracture resistance evaluated by analysis of variance and Tukey test. For the finite element analyses, an average UPM for each group was modeled in Rhinoceros CAD software and imported to Ansys 13.0. An average of 320,000 tetrahedral elements and 540,000 nodes for the seven models were performed using the same experimental simulation setup for each. The models were constrained on the base, and a displacement of 0.02 mm was applied to keep a linear behavior for the analysis. A von Mises stress and total displacement fields were used for the coherence test and the maximum principal stress fields were used for mechanical behavior comparisons. Group I (161.73 ± 22.94) showed a significantly higher mean value than the other experimental groups (EPc: 103.55 ± 15.84; CPc: 94.38 ± 12.35; CPr: 90.31 ± 6.10; EPr: 65.42 ± 10.15; CPnc: 65.46 ± 5.37; EPnc: 58.08 ± 9.62). The stress distribution was

  7. On the fracture of human dentin: Is it stress- orstrain-controlled?

    Nalla, R.K.; Kinney, J.H.; Ritchie, R.O.


    Despite substantial clinical interest in the fracture resistance of human dentin, there is little mechanistic information in archival literature that can be usefully used to model such fracture. In fact, although the fracture event indent in, akin to other mineralized tissues like bone, is widely believed to be locally strain-controlled, there has never been any scientific proof to support this belief. The present study seeks to address this issue through the use of a novel set of in vitro experiments in Hanks' balanced salt solution involving a double-notched bend test geometry, which is designed to discern whether the critical failure events involved in the onset of fracture are locally stress- or strain-controlled. Such experiments are further used to characterize the notion of ''plasticity'' in dentin and the interaction of cracks with the salient microstructural features. It is observed that fracture in dentin is indeed locally strain-controlled and that the presence of dentinal tubules does not substantially affect this process of crack initiation and growth. The results presented are believed to be critical steps in the development of a micromechanical model for the fracture of human dentin that takes into consideration the influence of both the microstructure and the local failure mode.

  8. Debriefing in the intensive care unit: a personal experience of critical incident stress.

    Cotterill-Walker, S


    With reference to two case studies this paper outlines critical incident stress (CIS) and describes the development of critical incident stress management (CISM) and its relevance to ICU. The current debate surrounding CISM is examined. CISM offers only one solution to CIS in critical care settings but it is in danger of being adopted without proper evaluation and research into its effectiveness. Provision of adequate staff support through clinical supervision may be easier to implement and more widely accepted by nursing staff than formal CISM strategies.

  9. Photoelastic stress analysis assisted evaluation of fracture toughness in hydrothermally aged epoxies

    G. Pitarresi


    Full Text Available The present work has investigated the fracture toughness of a model DGEBA epoxy system subject to Hidro-Thermal aging. A Photoelastic Stress Analysis technique has been implemented, showing the evolution of stresses arising throughout the water uptake process due to the non-uniform swelling of the material. Gravimetric and Dynamic Mechanical Thermal Analyses have further complemented the characterization, showing the onset of plasticization effects with aging. The correlation of all previous characterizations has allowed to conclude that an increase of KIC fracture toughness is obtained at the fully saturated condition. In particular Photoelasticity has also revealed the onset of relevant swelling induced stresses during the first stages of water absorption, leading to an increase of fracture toughness due to compressive stresses settling near the crack tip. A stress free condition is instead reestablished at the later stages of absorption, suggesting that the increased toughness of the saturated material is an effect of the modifications induced by aging on the polymer structure.

  10. Preventing construction worker injury incidents through the management of personal stress and organizational stressors.

    Leung, Mei-yung; Chan, Isabelle Yee Shan; Yu, Jingyu


    Construction workers (CWs) are positioned at the lowest level of an organization and thus have limited control over their work. For this reason, they are often deprived of their due rewards and training or sometimes are even compelled to focus on production at the expense of their own safety. These organizational stressors not only cause the CWs stress but also impair their safety behaviors. The impairment of safety behaviors is the major cause of CW injury incidents. Hence, to prevent injury incidents and enhance safety behaviors of CWs, the current study aimed to identify the impact of various organizational stressors and stress on CW safety behaviors and injury incidents. To achieve this aim, we surveyed 395 CWs. Using factor analysis, we identified five organizational stressors (unfair reward and treatment, inappropriate safety equipment, provision of training, lack of goal setting, and poor physical environment), two types of stress (emotional and physical), and safety behaviors. The results of correlation and regression analyses revealed the following: (1) injury incidents were minimized by safety behaviors but escalated by a lack of goal setting, (2) safety behaviors were maximized by moderate levels of emotional stress (i.e., an inverted U-shape relationship between these two variables) and increased in line with physical stress and inappropriate safety equipment, (3) emotional stress was positively predicted by the provision of training and inappropriate safety equipment, and (4) physical stress was predicted only by inappropriate safety equipment. Based on these results, we suggest various recommendations to construction stakeholders on how to prevent CW injury incidents. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. The association between hematological and inflammatory factors and stress fractures among female military recruits.

    Merkel, Drorit; Moran, Daniel S; Yanovich, Ran; Evans, Rachel K; Finestone, Aharon S; Constantini, Naama; Israeli, Eran


    With the growing number of females accepted for combat-related military duties in the Israeli Defense Forces, their special needs should be addressed. Previous studies on females in combat training have found a high prevalence of iron deficiency at recruitment as well as an increased rate of stress fractures (SF) and overuse injuries during training when compared with males. The aim of this study was to assess the correlation between hematological and inflammatory variables and SF occurrence among military recruits during basic training. Three gender-integrated light infantry units were followed prospectively. Female recruits inducted for medic and dental assistants' courses were followed for comparison. Hemoglobin, iron, transferrin, ferritin, C-reactive protein, and interleukin-6 levels were measured for all participants at recruitment and at 2 and 4 months of training. SF were diagnosed radiographically or scintigraphically according to the Israeli Defense Forces protocol. A total of 438 subjects were recruited (female combatants = 227, male combatants = 83, noncombatant females = 128). At induction, 18% of female combatants had anemia compared with 8% of males and 19% of noncombatants. Iron deficiency was noted in 40%, 6%, and 38%, respectively. There were no clinically significant changes during training. Twelve percent of female combatants developed SF, whereas none occurred among male combatants or noncombatants. Subjects sustaining an SF had significantly lower levels of serum iron and iron saturation. A high incidence of anemia as well as iron deficiency was found in this young asymptomatic cohort, with no significant change during training. The lower level of iron in female combatants sustaining SF warrants further investigation.

  12. Double Threaded Screw Fixation for Bilateral Stress Fracture of the Medial Malleolus

    Ryo Kanto


    Full Text Available An 18-year-old college basketball player presented with continued ankle pain. A radiographic examination showed bilateral medial malleolus stress fractures. Considering the prolonged history and refractory nature of this injury, surgery was adopted as a treatment option. At surgery, the fracture site was percutaneously fixed using two cannulated double threaded screws. Surgery for each side was sequentially performed two months apart. Prompt bony healing was attained after surgery, and the patient could return to his previous sports level six months after the first surgery without subsequent recurrence.

  13. Incidence and mortality of hip fracture among the elderly population in South Korea: a population-based study using the National Health Insurance claims data

    Choi Won-Jung


    Full Text Available Abstract Background The lack of epidemiologic information on osteoporotic hip fractures hampers the development of preventive or curative measures against osteoporosis in South Korea. We conducted a population-based study to estimate the annual incidence of hip fractures. Also, we examined factors associated with post-fracture mortality among Korean elderly to evaluate the impact of osteoporosis on our society and to identify high-risk populations. Methods The Korean National Health Insurance (NHI claims database was used to identify the incidence of hip fractures, defined as patients having a claim record with a diagnosis of hip fracture and a hip fracture-related operation during 2003. The 6-month period prior to 2003 was set as a 'window period,' such that patients were defined as incident cases only if their first record of fracture was observed after the window period. Cox's proportional hazards model was used to investigate the relationship between survival time and baseline patient and provider characteristics available from the NHI data. Results The age-standardized annual incidence rate of hip fractures requiring operation over 50 years of age was 146.38 per 100,000 women and 61.72 per 100,000 men, yielding a female to male ratio of 2.37. The 1-year mortality was 16.55%, which is 2.85 times higher than the mortality rate for the general population (5.8% in this age group. The risk of post-fracture mortality at one year is significantly higher for males and for persons having lower socioeconomic status, living in places other than the capital city, not taking anti-osteoporosis pharmacologic therapy following fracture, or receiving fracture-associated operations from more advanced hospitals such as general or tertiary hospitals. Conclusion This national epidemiological study will help raise awareness of osteoporotic hip fractures among the elderly population and hopefully motivate public health policy makers to develop effective national

  14. Incidence of Vertebral Fractures in Women with Systemic Lupus Erythematosus After 8 Years of Follow-Up.

    García-Carrasco, Mario; Mendoza-Pinto, Claudia; León-Vázquez, María de la Luz; Méndez-Martínez, Socorro; Etchegaray-Morales, Ivet; Montiel-Jarquín, Álvaro; Enriquez-Guerra, Miguel Angel; Muñóz-Guarneros, Margarita; Gálvez-Romero, José Luis; Soto-Santillán, Pamela; Cervera, Ricard


    The aim of this study was to evaluate possible associations between potential risk factors and the occurrence of established vertebral fractures (VF) in Mexican patients with systemic lupus erythematosus (SLE). Consecutive patients with SLE were enrolled in a prospective, observational study from 2006 to 2015. Information on potential risk factors, including demographics, clinical data, and bone mineral density (BMD) at the lumbar spine and hip on dual-energy X-ray absorptiometry was collected at baseline and follow-up. Semiquantitative analysis was used to determine incident VF on lateral thoracic and lumbar radiographs, defined as any vertebral body graded normal at baseline and at least mildly deformed (20-25% reduction or more in any vertebral height) during follow-up. Differences in baseline characteristics were assessed in patients with and without new radiographic VF. Of 110 SLE patients included, with a median follow-up of 8 (IQR 8-9) years, 22 (20%) had radiographic VF at baseline; 35 (32%) patients had a new VF. The annual incidence rate of new morphometric VF was 3.5 (95% CI 2.4-4.91) per 100 patient/years. Most fractures were mild or moderate and biconcave shaped. Incident VF were significantly associated with baseline BMD at the total hip and longer disease duration. Cumulative glucocorticoid dose, postmenopausal status, and previous prevalent VF were not associated with VF. In this SLE cohort in daily clinical practice, new VF were frequently present in SLE patients, especially those with longer disease duration and low-hip BMD.

  15. Stress evolution during 3D single-layer visco-elastic buckle folding: Implications for the initiation of fractures

    Liu, Xiaolong; Eckert, Andreas; Connolly, Peter


    Buckle folds of sedimentary strata commonly feature a variety of different fracture sets. Some fracture sets including outer arc tensile fractures and inner arc shear fractures at the fold hinge zones are well understood by the extensional and compressional strain/stress pattern. However, other commonly observed fracture sets, including tensile fractures parallel to the fold axis, tensile fractures cutting through the limb, extensional faults at the fold hinge, and other shear fractures of various orientations in the fold limb, fail to be intuitively explained by the strain/stress regimes during the buckling process. To obtain a better understanding of the conditions for the initiation of the various fractures sets associated with single-layer cylindrical buckle folds, a 3D finite element modeling approach using a Maxwell visco-elastic rheology is utilized. The influences of three model parameters with significant influence on fracture initiation are considered: burial depth, viscosity, and permeability. It is concluded that these parameters are critical for the initiation of major fracture sets at the hinge zone with varying degrees. The numerical simulation results further show that the buckling process fails to explain most of the fracture sets occurring in the limb unless the process of erosional unloading as a post-fold phenomenon is considered. For fracture sets that only develop under unrealistic boundary conditions, the results demonstrate that their development is realistic for a perclinal fold geometry. In summary, a more thorough understanding of fractures sets associated with buckle folds is obtained based on the simulation of in-situ stress conditions during the structural development of buckle folds.

  16. A Comparison between Deep and Shallow Stress Fields in Korea Using Earthquake Focal Mechanism Inversions and Hydraulic Fracturing Stress Measurements

    Lee, Rayeon; Chang, Chandong; Hong, Tae-kyung; Lee, Junhyung; Bae, Seong-Ho; Park, Eui-Seob; Park, Chan


    We are characterizing stress fields in Korea using two types of stress data: earthquake focal mechanism inversions (FMF) and hydraulic fracturing stress measurements (HF). The earthquake focal mechanism inversion data represent stress conditions at 2-20 km depths, whereas the hydraulic fracturing stress measurements, mostly conducted for geotechnical purposes, have been carried out at depths shallower than 1 km. We classified individual stress data based on the World Stress Map quality ranking scheme. A total of 20 FMF data were classified into A-B quality, possibly representing tectonic stress fields. A total of 83 HF data out of compiled 226 data were classified into B-C quality, which we use for shallow stress field characterization. The tectonic stress, revealed from the FMF data, is characterized by a remarkable consistency in its maximum stress (σ1) directions in and around Korea (N79±2° E), indicating a quite uniform deep stress field throughout. On the other hand, the shallow stress field, represented by HF data, exhibits local variations in σ1 directions, possibly due to effects of topography and geologic structures such as faults. Nonetheless, there is a general similarity in σ1 directions between deep and shallow stress fields. To investigate the shallow stress field statistically, we follow 'the mean orientation and wavelength analysis' suggested by Reiter et al. (2014). After the stress pattern analysis, the resulting stress points distribute sporadically over the country, not covering the entire region evenly. In the western part of Korea, the shallow σ1directions are generally uniform with their search radius reaching 100 km, where the average stress direction agrees well with those of the deep tectonic stress. We note two noticeable differences between shallow and deep stresses in the eastern part of Korea. First, the shallow σ1 orientations are markedly non-uniform in the southeastern part of Korea with their search radius less than 25 km

  17. EAP-based critical incident stress management: utilization of a practice-based assessment of incident severity level in responding to workplace trauma.

    DeFraia, Gary S


    Central to the field of trauma psychology is assessment of the impact of critical incidents on individuals, as measured by individual symptoms of stress. Accordingly, the trauma literature reflects a proliferation of clinical impact of event scales. Workplace incidents however, affect not only individual employees, but also work organizations, requiring a multi-level response. Critical incident stress management (CISM) is the most prevalent multi-level incident response strategy utilized by organizations, often through specialized CISM units operating within their employee assistance programs (EAPs). While EAP-based CISM units seeks to support both individuals and organizations, studies focused on individual stress dominate the literature, mirroring assessment scales that tend to emphasize clinical as opposed to organizational practice. This research contributes to less-prevalent studies exploring incident characteristics as disruptive to organizations, rather than clinical symptoms as disruptive to individuals. To measure incident disruption, an EAP-based CISM unit developed a critical incident severity scale. By analyzing this unit's extensive practice database, this exploratory study examines how critical incident severity level varies among various types of incidents. Employing the methodology of clinical data mining, this practice-based research generates evidence-informed practice recommendations in the areas of EAP-based CISM intake assessment, organizational consultation and incident response planning.

  18. Influence of Perceived Stress on Incident Amnestic Mild Cognitive Impairment: Results From the Einstein Aging Study.

    Katz, Mindy J; Derby, Carol A; Wang, Cuiling; Sliwinski, Martin J; Ezzati, Ali; Zimmerman, Molly E; Zwerling, Jessica L; Lipton, Richard B


    Stress is a potentially remediable risk factor for amnestic mild cognitive impairment (aMCI). Our objective is to determine whether perceived stress predicts incident aMCI and to determine if the influence of stress on aMCI is independent of known aMCI risk factors, particularly demographic variables, depression, and apolipoprotein genotype. The Einstein Aging Study is a longitudinal community-based study of older adults. The Perceived Stress Scale (PSS) was administered annually in the Einstein Aging Study to participants (N=507; 71 developed incident aMCI; mean follow-up time=3.6 y, SD=2.0) who were aged 70 years and older, free of aMCI and dementia at baseline PSS administration, and had at least 1 subsequent annual follow-up. Cox hazard models were used to examine time to aMCI onset adjusting for covariates. High levels of perceived stress are associated with a 30% greater risk of incident aMCI (per 5-point increase in PSS: hazard ratio=1.30; 95% confidence interval, 1.08-1.58) independent of covariates. The consistency of results after covariate adjustment and the lack of evidence for reverse causation in longitudinal analyses suggest that these findings are robust. Understanding of the effect of perceived stress on cognition may lead to intervention strategies that prevent the onset of aMCI and Alzheimer dementia.

  19. Numerical Simulation of Rock Fracturing under Laboratory True-Triaxial Stress Conditions

    Ghofrani Tabari, Mehdi; Hazzard, Jim; Young, R. Paul


    A True-triaxial test (TTT) also known as polyaxial test was carried out on saturated Fontainebleau sandstone to elevate our knowledge about the role of the intermediate principal stress on deformation, fracturing and failure patterns of the rock using acoustic emission (AE) monitoring. The induced AE activities were studied by location of the AE events and mapping them on the captured features in the post-mortem CT scan images of the failed sample. The time-lapse monitoring of the velocity structure and AE activity in the sample portrayed a deformational path which led to propagation of fractures and formation of failure patterns in the rock. Having these experimental results, we aimed at running a numerical model of our true-triaxial testing system using an Itasca software based on three-dimensional explicit finite-difference method called FLAC3D. The loads were applied at the end of each platen while the steel platens transferred the stress to the surface of the cubic specimen. In order to simulate the failure, randomly distributed strength demonstrated by Mohr-Columb failure criterion was implemented in the spatial elements of the model representing the random distribution of the micro-cracks. During the experiment, pseudo-boundary surfaces were formed along the minimum and intermediate principal stress axes in the rock due to non-uniform distribution of stress as a result of geometrical constraints including the corner effects and friction on the platen-rock surfaces. Both the real AE data as well as the numerical simulation verified that coalescence of micro-cracks mainly occurred around these pseudo-boundaries with highest stress gradients as well as highest velocity gradients in the rock specimen and formed curvi-planar fractures. The rock specimen strength and brittleness in the macro-scale was also obtained from the stress-strain curve which was consistent with the experimental laboratory measurements. Eventually, the failure of the rock specimen was




    Full Text Available Colles‟ fracture is confined to adult and usually is seen in women over the age of fifty who have fallen on the outstretched hand. EPL tendon is the most common extensor tendon to rupture after colles‟ fracture. To our belief the incidenc e of median nerve injury and EPL tendon rupture given in literature are much higher than what we see now a days, so with this aim we carried this study to find out the true incidence of CTS and EPL tendon rupture in Indian population. AIMS AND OBJECTIVES: To study 100 patients with colles‟ fracture for true incidence of Extensor Pollicis Longus (EPL Tendon rupture and Carpal Tunnel Syndrome (CTS in Indian Population. MATERIALS AND METHODS: In our study 100 patients with colles fracture were followed up at regural intervals and were evaluated clinically and radiogrphically to rule out complications like EPL tendon rupture and CTS. OBSERVATION AND RESULTS: In our study, we found 0% incidence of CTS and EPL tendon rupture. CONCLUS ION: Proper division of patients into displaced and un displaced fracture and treatment of displaced fracture being closed reduction and internal fixation with „K‟ wires and then cast application in neutral position i.e. supination without flexion at wrist joint and properly advised physiotheraphy after cast removal at one and half month should be advocated

  1. Stress corrosion-controlled rates of mode I fracture propagation in calcareous bedrock

    Voigtlaender, Anne; Leith, Kerry; Krautblatter, Michael


    Surface bedrock on natural rock slopes is subject to constant and cyclic environmental stresses (wind, water, wave, ice, seismic or gravitational). Studies indicate that these stresses range up to several hundred kPa, generally too low to cause macroscopic changes in intact rock, although clear evidence of fracture generation, crack propagation and weathering of bedrock illustrates the effect of environmental stresses at the Earth's surface. We suggest that material degradation and its extent, is likely to be controlled by the rate of stress corrosion cracking (SCC). Stress corrosion is a fluid-material reaction, where fluids preferentially react with strained atomic bonds at the tip of developing fractures. Stress corrosion in ferrous and siliceous materials is often accepted as the fracture propagation and degradation rate-controlling process where materials are subject to stresses and fluids. Although evidence for chemical weathering in propagating bedrock fractures is clear in natural environments, the physical system and quantification of stress corrosion in natural rocks is yet to be addressed. Here, we present preliminary data on the relationship between stresses at levels commonly present on natural rock slopes, and material damage resulting from stress corrosion under constant or cyclic tensile loading. We undertake single notch three-point bending tests (SNBT) on fresh calcareous bedrock specimens (1100x100x100mm) over a two-month period. Two beams containing an artificial notch are stressed to 75% of their ultimate strength, and a constant supply of weak acid is applied at the notch tip to enhance chemical reactions. A third, unloaded, beam is also exposed to weak acid in order to elucidate the contribution of stress corrosion cracking to the material degradation. Stresses at the tip of propagating cracks affect the kinetics of the chemical reaction in the specimen exposed to both loading and corrosion, leading to an increase in degradation, and greater

  2. Critical Incident Stress Debriefing as a Trauma Intervention in First Nation Communities

    Hughes, Megan L.


    This study examines the appropriateness of a cross-cultural application of Critical Incident Stress Debriefing (CISD). Participant/observations were made of CISD workshops conducted for First Nations participants. The facilitator and five participants were interviewed using narrative methodology. Observations and interview data were examined using…

  3. Social Validity of the Critical Incident Stress Management Model for School-Based Crisis Intervention

    Morrison, Julie Q.


    The Critical Incident Stress Management (CISM) model for crisis intervention was developed for use with emergency service personnel. Research regarding the use of the CISM model has been conducted among civilians and high-risk occupation groups with mixed results. The purpose of this study is to examine the social validity of the CISM model for…

  4. Screening and Predicting Posttraumatic Stress and Depression in Children Following Single-Incident Trauma

    Nixon, Reginald D. V.; Ellis, Alicia A.; Nehmy, Thomas J.; Ball, Shelley-Anne


    Three screening methods to predict posttraumatic stress disorder (PTSD) and depression symptoms in children following single-incident trauma were tested. Children and adolescents (N = 90; aged 7-17 years) were assessed within 4 weeks of an injury that led to hospital treatment and followed up 3 and 6 months later. Screening methods were adapted…

  5. Emergency response service personnel and the critical incident stress debriefing debate.

    Wagner, Shannon L


    Previous research has demonstrated the potential for work-related stress associated with employment in the emergency service field. However, little research has considered effective interventions that may be used to mediate the effects of this work-related stress. Critical Incident Stress Debriefing (CISD) is one intervention that is currently employed with emergency service workers. However, the efficacy of this intervention is currently the source of much debate. The present discussion reviews the available literature regarding the effectiveness of CISD for use with emergency service workers and concludes that at this time, for this population, the call for the removal of current programs using CISD is unwarranted.

  6. A group randomized trial of critical incident stress debriefing provided to U.S. peacekeepers.

    Adler, Amy B; Litz, Brett T; Castro, Carl Andrew; Suvak, Michael; Thomas, Jeffrey L; Burrell, Lolita; McGurk, Dennis; Wright, Kathleen M; Bliese, Paul D


    In a group randomized trial of critical incident stress debriefing (CISD) with platoons of 952 peacekeepers, CISD was compared with a stress management class (SMC) and survey-only (SO) condition. Multilevel growth curve modeling found that CISD did not differentially hasten recovery compared to the other two conditions. For those soldiers reporting the highest degree of exposure to mission stressors, CISD was minimally associated with lower reports of posttraumatic stress and aggression (vs. SMC), higher perceived organizational support (vs. SO), and more alcohol problems than SMC and SO. Soldiers reported that they liked CISD more than the SMC, and CISD did not cause undue distress.

  7. Revisiting fracture gradient: Comments on “A new approaching method to estimate fracture gradient by correcting Matthew–Kelly and Eaton's stress ratio”

    Hakiki, Farizal


    A study performed by Marbun et al. [1] claimed that “A new methodology to predict fracture pressure from former calculations, Matthew–Kelly and Eaton are proposed.” Also, Marbun et al.\\'s paper stated that “A new value of Poisson\\'s and a stress ratio of the formation were generated and the accuracy of fracture gradient was improved.” We found those all statements are incorrect and some misleading concepts are revealed. An attempt to expose the method of fracture gradient determination from industry practice also appears to solidify that our arguments are acceptable to against improper Marbun et al.\\'s claims.

  8. Calcaneal stress fracture: an adverse event following total hip and total knee arthroplasty: a report of five cases.

    Miki, Takaaki; Miki, Takahito; Nishiyama, Akihiro


    Stress fractures have been reported to occur in the pubis, femoral neck, proximal part of the tibia, and fabella during the postoperative period following total knee or total hip arthroplasty. However, to our knowledge, calcaneal stress fractures after total hip or total knee arthroplasty have not been reported in the English-language literature. Most orthopaedic surgeons are not familiar with calcaneal stress fractures that may occur in elderly patients after a total knee or total hip arthroplasty. We retrospectively reviewed the clinical features, imaging findings, and bone mineral content of the proximal part of the femur and the distal end of the radius in five patients who had a calcaneal stress fracture after a total knee or total hip arthroplasty. All patients were women with a mean age of 76.8 years. All fractures occurred in the calcaneus on the same side as the arthroplasty. The fracture appeared at a mean of 10.2 weeks postoperatively. All patients reported heel pain on walking. Swelling and local heat were found in four and three patients, respectively. Pain was elicited by squeezing the calcaneus in all patients. Early radiographs had normal findings in two patients, and an irregular sclerotic line appeared later in the radiographs of all patients. All fractures were treated conservatively. Four fractures healed uneventfully, but one fracture displaced. All patients had osteoporosis. Calcaneal stress fractures during the postoperative period following total knee or total hip arthroplasty may not be as rare as previously thought. Because clinical symptoms of the fracture appear insidiously and radiographic findings are absent or subtle in the early stage, a high index of suspicion is needed for orthopaedic surgeons to make the correct diagnosis. Magnetic resonance imaging or repeated radiographs may be necessary to make the correct diagnosis when no abnormality is apparent on the initial radiograph.

  9. Low-Level Cadmium Exposure Is Associated With Decreased Bone Mineral Density and Increased Risk of Incident Fractures in Elderly Men: The MrOS Sweden Study.

    Wallin, Maria; Barregard, Lars; Sallsten, Gerd; Lundh, Thomas; Karlsson, Magnus K; Lorentzon, Mattias; Ohlsson, Claes; Mellström, Dan


    One risk factor for osteoporosis that has attracted increasing attention in recent years is exposure to cadmium. The aim of this study was to examine the associations between low-level cadmium exposure, from diet and smoking, and bone mineral density (BMD) and incident fractures in elderly men. The study population consisted of 936 men from the Swedish cohort of the Osteoporotic Fractures in Men (MrOS) study, aged 70 to 81 years at inclusion (years 2002 to 2004), with reliable data on cadmium in urine (U-Cd) analyzed using inductively coupled plasma mass spectrometry in baseline samples. The participants also answered a questionnaire on lifestyle factors and medical history. BMD was measured at baseline using dual-energy X-ray absorptiometry (DXA) in the total body, hip, and lumbar spine. During the follow-up period (until 2013), all new fractures were registered by date and type. Associations between BMD and U-Cd were assessed using multiple linear regression, and associations between incident fractures and baseline U-Cd were analyzed using Cox regression. In both cases, a number of potential confounders and other risk factors (eg, age, smoking, body mass index [BMI], and physical activity) were included in the models. We found significant negative associations between U-Cd and BMD, with lower BMD (4% to 8%) for all sites in the fourth quartile of U-Cd, using the first quartile as the reference. In addition, we found positive associations between U-Cd and incident fractures, especially nonvertebral osteoporosis fractures in the fourth quartile of U-Cd, with hazard ratios of 1.8 to 3.3 in the various models. U-Cd as a continuous variable was significantly associated with nonvertebral osteoporosis fractures (adjusted hazard ratio 1.3 to 1.4 per μg Cd/g creatinine), also in never-smokers, but not with the other fracture groups (all fractures, hip fractures, vertebral fractures, and other fractures). Our results indicate that even relatively low cadmium exposure


    Daniel R. Burns; M. Nafi Toksoz


    We have extended a three-dimensional finite difference elastic wave propagation model previously developed at the Massachusetts Institute of Technology (MIT) Earth Resources Laboratory (ERL) for modeling and analyzing the effect of fractures on seismic waves. The code has been translated into C language and parallelized [using message passing interface (MPI)] to allow for larger models to be run on Linux PC computer clusters. We have also obtained another 3-D code from Lawrence Berkeley Laboratory, which we will use for verification of our ERL code results and also to run discrete fracture models. Testing of both codes is underway. We are working on a new finite difference model of borehole wave propagation for stressed formations. This code includes coordinate stretching to provide stable, variable grid sizes that will allow us to model the thin fluid annulus layers in borehole problems, especially for acoustic logging while drilling (LWD) applications. We are also extending our analysis routines for the inversion of flexural wave dispersion measurements for in situ stress estimates. Initial results on synthetic and limited field data are promising for a method to invert cross dipole data for the rotation angle and stress state simultaneously. A meeting is being scheduled between MIT and Shell Oil Company scientists to look at data from a fractured carbonate reservoir that may be made available to the project. The Focus/Disco seismic processing system from Paradigm Geophysical has been installed at ERL for field data analysis and as a platform for new analysis modules. We have begun to evaluate the flow properties of discrete fracture distributions through a simple 2D numerical model. Initial results illustrate how fluid flow pathways are very sensitive to variations in the geometry and apertures of fracture network.

  11. Ductile fracture of metals under triaxial states of stress

    Schrems, Karol Krumrey

    Silver interlayers between maraging steel base metal were examined to evaluate mechanisms leading to ductile failure in constrained thin metals. The constraint of the maraging steel base metal during uniaxial testing of constrained thin silver results in a large hydrostatic tension component, a small von Mises effective stress, and negligible far-field plasticity. The failure theory proposed by Rice and Tracey predicts uniform cavity wall expansion as a result of high triaxiality, in which an increase in plastic strain drives an increase in cavity size. The Rice and Tracey theory predicts significantly greater plastic strain than is experimentally observed. The theory developed by Huang, Hutchinson, and Tvergaard states that a cavitation limit exists at which a cavity continues to grow without an increase in elastic or plastic strain. This occurs when the energy stored in the elastic region is sufficient to drive continued cavity expansion. Inherent in both theories is the assumption of a single cavity in an infinite solid, which implies non-interacting cavities. Modifications have been developed to allow for multiple cavities, but assume pre-existing cavities. By examining silver interlayers previously loaded to various times at a fraction of the tensile strength where time-dependent failure is observed, it was found that some cavities were initially present in the as-bonded samples. Some of the initial cavities were spaced close enough to suggest localized interacting stress fields. This indicates that a failure model should be able to accommodate cavity spacing. The results suggest that cavities are continuously nucleating (from at least the 20 nanometers detectability limit) and grow, sometimes to over 500 nm in diameter. This thesis evaluates the number, size, shape and spacing of cavities in the silver interlayers and uses these results to evaluate ductile failure theories for metals subjected to high triaxial states of stress such as in constrained

  12. Care after chaos: use of critical incident stress debriefing after traumatic workplace events.

    Sacks, S B; Clements, P T; Fay-Hillier, T


    CISD is a specific model of group debriefing, which can be used to accelerate recovery from traumatic work-place events. The impact of critical incidents may be debilitating-from recurrent intrusive images, persistent fear, displaced anger, guilt, and isolation. CISD can accomplish psychological closure, prevention, and mitigation of traumatic stress, and promote return to normalcy, benefiting the individual, organization, and the community at large. The field of critical incident stress management is open to advanced practice nurses who seek to apply their crisis-intervention expertise within a nontraditional role and workplace setting. With specialized training, the advanced practice nurse may pursue a career as a crisis-response provider, working independently or with an established CISM team. Practice requirements include CISM certification, along with the acquisition of a referral source. The prevention and mitigation of traumatic stress can yield a rewarding career in CISM.

  13. Extension of in-situ stress test analysis to fractured media with reference to Yucca Mountain data

    Davies, J.B.


    Yucca Mountain is underlain by highly fractured rock containing a deep water table. Stress tests have been performed in boreholes in-situ and under high head pressures. For a pre-fractured rock system, data analysis must incorporate the effects of opening and closing of fractures. As the head pressure increases form ambient, the aperture of the existing dilated fractures increase. The fracture surface area remains constant until the excess head increases to above a critical pressure, when induced fractures can open and existing fractures may propagate. These will furnish a larger rock surface area thereby allowing a more rapid percolation of the water into the rock matrix. We have extended previous models by specifying a functional dependence of both existing fracture aperture and induced fracture surface area and volume on the excess water pressure. Relationships are obtained through the mass conservation laws and these predictions are used as discriminative graphs, with the most useful being pressure versus rate of pressure change. Such type-curves are applied to; Yucca Mountain data with interpretation in terms of the applicable fracture systems and the critical pressure. Estimates of the critical pressure are obtained and usually lie in the range of 10 to 30 bars which is appreciably lower than that expected from the lithostatic pressure effects. This implies that large dilational stresses exist at Yucca Mountain.

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

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


    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. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  15. The Pennsylvania Experience with Hydraulic Fracturing for Shale Gas Development: Relatively Infrequent Water Quality Incidents with Lots of Public Attention

    Brantley, S. L.; Li, Z.; Yoxtheimer, D.; Vidic, R.


    New techniques of hydraulic fracturing - "fracking" - have changed the United States over the last 10 years into a leading producer of natural gas extraction from shale. The first such gas well in Pennsylvania was drilled and completed using high-volume hydraulic fracturing in 2004. By late 2014, more than 8500 of these gas wells had been drilled in the Marcellus Shale gas field in Pennsylvania alone. Almost 1000 public complaints about groundwater quality were logged by the PA Department of Environmental Protection (PA DEP) between 2008 and 2012. Only a fraction of these were attributed to unconventional gas development. The most common problem was gas migration into drinking water, but contamination incidents also included spills, seepage, or leaks of fracking fluids, brine salts, or very occasionally, radioactive species. Many problems of gas migration were from a few counties in the northeastern part of the state. However, sometimes one gas well contaminated multiple water wells. For example, one gas well was reported by the state regulator to have contaminated 18 water wells with methane near Dimock PA. It can be argued that such problems at a relatively small fraction of gas wells initiated pockets of pushback against fracking worldwide. This resistance to fracking has grown even though fracking has been in use in the U.S.A. since the 1940s. We have worked as part of an NSF-funded project (the Shale Network) to share water quality data and publish it online using the CUAHSI Hydrologic Information System. Sharing data has led to collaborative investigation of specific contamination incidents to understand how problems can occur, and to efforts to quantify the frequency of impacts. The Shale Network efforts have also highlighted the need for more transparency with water quality data in the arena related to the energy-water nexus. As more data are released, new techniques of data analysis will allow better understanding of how to tune best practices to be

  16. The detection and characterization of natural fractures using P-wave reflection data, multicomponent VSP, borehole image logs and the in-situ stress field determination

    Hoekstra, P. [Coleman Research Corp., Orlando, FL (United States)


    The objectives of this project are to detect and characterize fractures in a naturally fractured tight gas reservoir, using surface seismic methods, borehole imaging logs, and in-situ stress field data. Further, the project aims to evaluate the various seismic methods as to their effectiveness in characterizing the fractures, and to formulate the optimum employment of the seismic methods as regards fracture characterization.

  17. Presentation of metastatic carcinoma as pedal stress fracture and ingrown toenail.

    Mitchell, Dianne I; Riley, Philip J


    Metastatic lesions localized to the foot are rare. When present, such lesions are typically associated with a poor prognosis. A good history can help guide the clinician when formulating differential diagnoses for a questionable clinical presentation. We report the case of a patient presenting with findings indicative of a metatarsal stress fracture and an ingrown toenail, which eventually resulted in the diagnosis of metastatic disease from the lung. ACFAS Level of Clinical Evidence: 4.

  18. Risk Stratification of Stress Fractures and Prediction of Return to Duty


    provision of law, no person shall be subject to any penalty for fai ling to comply with a collection of information if it does not display a currently valid...include IRB and HRPO approvals for all study protocols, hiring and training of staff at MGH, as well as the initiation of subject recruitment and...enrollment. In study Task 1 we aim to determine the sex- and race-ethnicity-specific bone traits that may contribute to stress fracture risk in military

  19. The Incidence of Posttraumatic Stress Disorder After Floods: A Meta-Analysis.

    Chen, Long; Liu, Aizhong


    This study analyzes the incidence of posttraumatic stress disorder (PTSD) among flood victims, between different flood intensities, and between different time points after a flood. A search of several electronic literature databases was conducted to collect data on the incidence of PTSD after a flood. Loney criteria for research quality were used to evaluate the quality of selected search results. The combined incidence of PTSD was estimated using the Freeman-Tukey double arcsine transformation method. Subgroup analyses were conducted on different trauma intensities and different time points after a flood. Sensitivity analysis was performed to evaluate the impact of research quality. Fourteen articles were included in this meta-analysis, including a total of 40 600 flood victims; 3862 victims were diagnosed with PTSD. The combined incidence of PTSD was 15.74%. The subgroup analyses showed that the incidence of PTSD in victims who experienced severe and moderate flood intensity was higher than that in victims who experienced mild flood intensity. The incidence of PTSD was lower at 6 or more months after a flood (11.45%) than within 6 months (16.01%) of a flood. In conclusion, the incidence of PTSD among floods of different trauma intensities was statistically significant.

  20. Stress fractures of the base of the metatarsal bones in young trainee ballet dancers.

    Albisetti, Walter; Perugia, Dario; De Bartolomeo, Omar; Tagliabue, Lorenzo; Camerucci, Emanuela; Calori, Giorgio Maria


    Classical ballet is an art form requiring extraordinary physical activity, characterised by rigorous training. These can lead to many overuse injuries arising from repetitive minor trauma. The purpose of this paper is to report our experience in the diagnosis and treatment of stress fractures at the base of the second and third metatarsal bones in young ballet dancers. We considered 150 trainee ballet dancers from the Ballet Schools of "Teatro Alla Scala" of Milan from 2005 to 2007. Nineteen of them presented with stress fractures of the base of the metatarsal bones. We treated 18 dancers with external shockwave therapy (ESWT) and one with pulsed electromagnetic fields (EMF) and low-intensity ultrasound (US); all patients were recommended rest. In all cases good results were obtained. The best approach to metatarsal stress fractures is to diagnose them early through clinical examination and then through X-ray and MRI. ESWT gave good results, with a relatively short time of rest from the patients' activities and a return to dancing without pain.

  1. Incidence of bacteremia in stressed and unstressed populations of the blue crab, Callinectes sapidus.

    Welsh, P C; Sizemore, R K


    The incidence of bacteremia in the blue crab, Callinectes sapidus, is reported to be in excess of 80%. Because these results have been controversial, a field study was initiated to determine the effect of commercial capture and handling stresses on the incidence and levels of infection in blue crabs. The majority (75%) of "unstressed" crabs which were captured individually and bled immediately upon removal from the water were bacteremic, with a geometric mean level of infection of 14 CFU/ml of hemolymph. Crabs collected by crab pot, confined within these pots for as long as 24 h, and sampled immediately after removal from the water had a similar mean level of infection. Crabs subjected to the stresses of commercial capture, handling, and transport showed a higher incidence of infection (91%) and a mean infection level of 46 CFU/ml. Injuries sustained by crabs during commercial handling are thought to be associated with the higher incidence of infection. Vibrio spp. were primarily responsible for progressive infections in commercially stressed crabs and were the predominant bacterial type in heavily infected crabs. Our results indicated that uninjured healthy crabs do not have sterile hemolymph but instead harbor low-level bacterial infections. PMID:4051486

  2. Supporting the Federal Emergency Management Agency Rescuers: a variation of critical incident stress management.

    Garcia, Evangeline; Horton, Denise A


    The purpose of this article was to document the efforts of two military installations in facilitating Critical Incident Stress Management teams for Federal Emergency Management Agency Rescue and Recovery Units following the attacks on the World Trade Center on September 11, 2001. McGuire Air Force Base accepted the mission to support the rotating task forces with emotional support, and Fort Dix offered temporary lodging while the teams were in-bound and out-bound to the "Ground Zero" site. A team, comprised of staff from both installations due to the configuration of professional and support staffs, does the Critical Incident Stress Management work. Both installations are within commuting distance of New York City and could provide adequate safety, security, and logistics to the teams. The classic crisis management models were not called into play, as that service was not asked for; however, it was clear to the McGuire Air Force Base/Fort Dix Critical Incident Stress Management team members that the rescue and recovery teams needed their physical presence. Many rescue organizations have their own "debriefing teams," yet it is believed that "outside teams" may be helpful as interim measures to demonstrate the universality of the process of coping with traumatic stress and grief management. It is hoped that this article honors the workers who came together to help in a very difficult time for our country. This article documents the interim measures that were taken for a group of people moving through crisis.

  3. FAST TRACK PAPER: The creation of an asymmetric hydraulic fracture as a result of driving stress gradients

    Fischer, T.; Hainzl, S.; Dahm, T.


    Hydraulic fracture stimulation is frequently performed in hydrocarbon reservoirs and geothermal systems to increase the permeability of the rock formation. These hydraulic fractures are often mapped by hypocentres of induced microearthquakes. In some cases microseismicity exhibits asymmetry relative to the injection well, which can be interpreted by unequal conditions for fracture growth at opposite sides of the well or by observation effects. Here we investigate the role of the lateral change of the minimum compressive stress. We use a simple model to describe the relation among the lateral stress gradient, the mean viscous pressure gradients in the fracture wings, the fracture geometry, and the net pressure in the fracture. Our model predicts a faster fracture growth in the direction of decreasing stress and a limited growth in the opposite direction. We derive a simple relationship to estimate the lateral stress gradient from the injection pressure and the shape of the seismic hypocentre cloud. The model is tested by microseismic data obtained during stimulation of a Canyon Sands gas field in West Texas. Using a maximum likelihood method we fit the parameters of the asymmetric fracture model to the space-time pattern of hypocentres. The estimated stress gradients per metre are in the range from 0.008 to 0.010 times the bottom-hole injection overpressure (8-10 kPam-1 assuming the net pressure of 1 MPa). Such large horizontal gradients in the order of the hydrostatic gradient could be caused by the inhomogeneous extraction of gas resulting in a lateral change of the effective normal stress acting normal to the fracture wall.


    Walter, Matthew [Structural Integrity Associates, Inc.; Yin, Shengjun [ORNL; Stevens, Gary [U.S. Nuclear Regulatory Commission; Sommerville, Daniel [Structural Integrity Associates, Inc.; Palm, Nathan [Westinghouse Electric Company, Cranberry Township, PA; Heinecke, Carol [Westinghouse Electric Company, Cranberry Township, PA


    In past years, the authors have undertaken various studies of nozzles in both boiling water reactors (BWRs) and pressurized water reactors (PWRs) located in the reactor pressure vessel (RPV) adjacent to the core beltline region. Those studies described stress and fracture mechanics analyses performed to assess various RPV nozzle geometries, which were selected based on their proximity to the core beltline region, i.e., those nozzle configurations that are located close enough to the core region such that they may receive sufficient fluence prior to end-of-life (EOL) to require evaluation of embrittlement as part of the RPV analyses associated with pressure-temperature (P-T) limits. In this paper, additional stress and fracture analyses are summarized that were performed for additional PWR nozzles with the following objectives: To expand the population of PWR nozzle configurations evaluated, which was limited in the previous work to just two nozzles (one inlet and one outlet nozzle). To model and understand differences in stress results obtained for an internal pressure load case using a two-dimensional (2-D) axi-symmetric finite element model (FEM) vs. a three-dimensional (3-D) FEM for these PWR nozzles. In particular, the ovalization (stress concentration) effect of two intersecting cylinders, which is typical of RPV nozzle configurations, was investigated. To investigate the applicability of previously recommended linear elastic fracture mechanics (LEFM) hand solutions for calculating the Mode I stress intensity factor for a postulated nozzle corner crack for pressure loading for these PWR nozzles. These analyses were performed to further expand earlier work completed to support potential revision and refinement of Title 10 to the U.S. Code of Federal Regulations (CFR), Part 50, Appendix G, Fracture Toughness Requirements, and are intended to supplement similar evaluation of nozzles presented at the 2008, 2009, and 2011 Pressure Vessels and Piping (PVP

  5. Residual stress and damage-induced critical fracture on CO2 laser treated fused silica

    Matthews, M; Stolken, J; Vignes, R; Norton, M


    Localized damage repair and polishing of silica-based optics using mid- and far-IR CO{sub 2} lasers has been shown to be an effective method for increasing optical damage threshold in the UV. However, it is known that CO{sub 2} laser heating of silicate surfaces can lead to a level of residual stress capable of causing critical fracture either during or after laser treatment. Sufficient control of the surface temperature as a function of time and position is therefore required to limit this residual stress to an acceptable level to avoid critical fracture. In this work they present the results of 351 nm, 3 ns Gaussian damage growth experiments within regions of varying residual stress caused by prior CO{sub 2} laser exposures. Thermally stressed regions were non-destructively characterized using polarimetry and confocal Raman microscopy to measure the stress induced birefringence and fictive temperature respectively. For 1 {approx} 40s square pulse CO{sub 2} laser exposures created over 0.5-1.25 kW/cm{sup 2} with a 1-3 mm 1/e{sup 2} diameter beam (T{sub max} {approx} 1500-3000 K), the critical damage site size leading to fracture increases weakly with peak temperature, but shows a stronger dependence on cooling rate, as predicted by finite element hydrodynamics simulations. Confocal micro-Raman was used to probe structural changes to the glass over different thermal histories and indicated a maximum fictive temperature of 1900K for T{sub max} {ge} 2000 K. The effect of cooling rate on fictive temperature caused by CO{sub 2} laser heating are consistent with finite element calculations based on a Tool-Narayanaswamy relaxation model.

  6. Trends in incidence rate, health care consumption, and costs for patients admitted with a humeral fracture in The Netherlands between 1986 and 2012

    K.C. Mahabier (Kiran); D. den Hartog (Dennis); M.J.M. Panneman (Martien); J.R. van Veldhuizen (Joyce); S. Polinder (Suzanne); M.H.J. Verhofstad (Michiel); E.M.M. van Lieshout (Esther)


    textabstractIntroduction: This study aimed to examine long-term population-based trends in the incidence rate of patients with a humeral fracture admitted to a hospital in the Netherlands from 1986 to 2012 and to give a detailed overview of the health care consumption and productivity loss with asso

  7. The incidence of technological stress among baccalaureate nurse educators using technology during course preparation and delivery.

    Burke, Mary S


    The concept of technology-related stress was first introduced in the 1980s when computers became more prevalent in the business and academic world. Nurse educators have been impacted by the rapid changes in technology in recent years. A review of the literature revealed no research studies that have been conducted to investigate the incidence of technological stress among nurse educators. The purpose of this descriptive-correlational study was to describe the technological stressors that Louisiana baccalaureate nurse educators experienced while teaching nursing theory courses. A researcher-developed questionnaire, the nurse educator technostress scale (NETS) was administered to a census sample of 311 baccalaureate nurse educators in Louisiana. Findings revealed that Louisiana baccalaureate nurse educators are experiencing technological stress. The variable, perceived administrative support for use of technology in the classroom, was a significant predictor in a regression model predicting Louisiana baccalaureate nurse educators' technological stress (F=14.157, p<.001).

  8. Depth-dependent expression of obliquely incident wave induced radiation stress


    The vertically dependent expressions of obliquely incident waves induced radiation stress are derived by use of the second order Stokes wave theory within three regions of the water column, that is, above the mean water level, below the wave trough level, and between these two levels. Computations indicate that the wave-induced radiation stress below the wave trough level is from the water wave particle velocity only, whereas both the water wave particle velocity and the wave pressure contribute to the tensor above the wave trough level; the vertical variations of the wave-induced radiation stress are influenced substantially by the velocity component in the direction of wave propagation; the distributions of the wave-induced radiation stress tensor over depth are non-uniform and the proportion of the tensor below the wave trough level becomes considerable in the shallow water; from water surface to seabed, the reversed variations occur for the predominant tensor components.

  9. Anisotropic stress accumulation in cooling lava flows and resulting fracture patterns: Insights from starch-water desiccation experiments

    Lodge, Robert W. D.; Lescinsky, David T.


    Desiccation of starch-water slurries is a useful analog for the production of polygonal fractures/columnar joints in cooling lava flows. When left to dry completely, a simple mixture of 1:1 starch and water will produce columns that appear remarkably similar to natural columnar joints formed in cooled lava flows. Columns form when the accumulation of isotropic stress exceeds the tensile strength of a material, at which point a fracture forms and advances through the material perpendicular to the desiccating surface. Individual fractures will initially form orthogonal to the desiccation surface but will quickly evolve into a hexagonal fracture network that advances incrementally through the material. However, some fracture patterns found within natural lava flows are not hexagonal ( Lodge and Lescinsky, 2009-this issue), but rather have fracture lengths that are much longer than the distance to adjacent fractures. These fractures are commonly found at lava flows that have interacted with glacial ice during emplacement. The purpose of this study is to utilize starch analog experiments to better understand the formation of these fractures and the stress regimes responsible for their non-hexagonal patterns. To simulate anisotropic conditions during cooling, the starch slurry was poured into a container with a movable wall that was attached to a screw-type jack. The jack was then set to slowly extend or retract while the slurry desiccated. This resulted in either a decrease or increase in the chamber cross-sectional area thus creating compressional or extensional regimes. Decreasing chamber area (DCA) experiments resulted in fractures with larger lengths parallel to the direction of wall movement (also direction of compression). It also caused localized thrust faulting and curved column development. Increasing chamber area (ICA) experiments produced a zone of horizontal column development along the expanding margin (produced when the wall detached from the sample

  10. On the Relationship between Stress and Elastic Strain for Porous and Fractured Rock

    Liu, Hui-Hai; Rutqvist, Jonny; Berryman, James G.


    Modeling the mechanical deformations of porous and fractured rocks requires a stress-strain relationship. Experience with inherently heterogeneous earth materials suggests that different varieties of Hook's law should be applied within regions of the rock having significantly different stress-strain behavior, e.g., such as solid phase and various void geometries. We apply this idea by dividing a rock body conceptually into two distinct parts. The natural strain (volume change divided by rock volume at the current stress state), rather than the engineering strain (volume change divided by the unstressed rock volume), should be used in Hooke's law for accurate modeling of the elastic deformation of that part of the pore volume subject to a relatively large degree of relative deformation (i.e., cracks or fractures). This approach permits the derivation of constitutive relations between stress and a variety of mechanical and/or hydraulic rock properties. We show that the theoretical predictions of this method are generally consistent with empirical expressions (from field data) and also laboratory rock experimental data.

  11. State of stress, permeability, and fractures in the Precambrian granite of northern Illinois

    Haimson, Bezalel C.; Doe, Thomas W.


    In situ fracture logging, permeability tests, and stress measurements have been conducted in UPH 3, a 1600-m-deep hole drilled into the Precambrian granitic basement of northern Illinois. Two major fracture zones are revealed, which cannot be discerned in UPH 2, a similarly deep hole about 1 km away. The segments of the UPH 3 core that were oriented indicate the existence of three sets of subvertical joints striking at N55°E, N40°W and E-W. These sets correspond to surface and shallow borehole joint directions in the Precambrian and Paleozoic rock of southern Wisconsin as well as other areas of the Midwest. The permeability values in UPH 3 display an overall reduction with depth from about 10-4 darcy at 700 m to 10-8-10-9 darcy at 1600 m. Permeability is highest in the zones of greatest fracturing, one of which occurs near the top of the granite and is probably related to fractures which were formed when the granite was at the surface in late Paleozoic times. Permeability reduction with depth is consistent with previous laboratory and field results in crystalline rocks. Hydrofracturing measurements in UPH 3 reveal a compressional stress field with the largest stress horizontal and oriented at N48°E (±30°). Based on linear regression of 13 test results in the depth range of 686-1449 m, the greatest horizontal stress has a magnitude of [20.5+(0.023×depth(m))] MPa. The least horizontal compression has a value of [8.7+(0.019×depth(m))] MPa. The vertical stress, based on density measurements, is given by [-1.3+(0.026xdepth(m))] MPa. Both magnitudes and directions support previous results in the technically stable Great Lakes region of the midcontinent. However, a mb = 4.4 earthquake did occur in 1972 some 90 km south of UPH 3, at a depth of 13 km. The focal mechanism solution revealed strike slip motion with the pressure axis horizontal and trending northeast, in accord with our measured stress directions and relative magnitudes but not predicted from a

  12. Mantram repetition for stress management in veterans and employees: a critical incident study.

    Bormann, Jill E; Oman, Doug; Kemppainen, Jeanne K; Becker, Sheryl; Gershwin, Madeline; Kelly, Ann


    This paper reports a study assessing the usefulness of a mantram repetition programme. Complementary/alternative therapies are becoming commonplace, but more research is needed to assess their benefits. A 5-week programme teaching a 'mind-body-spiritual' technique of silently repeating a mantram - a word or phrase with spiritual meaning - to manage stress was developed. A mantram was chosen by individuals, who were taught to repeat it silently throughout the day or night to interrupt unwanted thoughts and elicit the relaxation response. Participants who attended a 5-week course were invited to participate in the study. Of those who consented, a randomly selected subset (n = 66) was contacted approximately 3 months after the course for a telephone interview using the critical incident interviewing technique. Participants were asked whether the intervention was helpful or not, and if helpful, to identify situations where it was applied. Interviews were transcribed and incidents were identified and categorized to create a taxonomy of uses. The data were collected in 2001-2002. Participants included 30 veterans, mostly males (97%), and 36 hospital employees, mostly females (86%). Mean age was 56 years (sd = 12.94). Fifty-five participants (83.3%) practiced the technique and reported 147 incidents where the programme was helpful. Outcomes were organized into a taxonomy of incidents using four major categories that included managing: (a) emotions other than stress (51%); (b) stress (23.8%); (c) insomnia (12.9%); and (d) unwanted thoughts (12.3%). A group of raters reviewed the categories for inter-rater reliability. The majority of participants from two distinct samples reported that the mantram programme was helpful in a variety of situations. The critical incident interviewing method was found to be practical, efficient, and thorough in collecting and analyzing data. Such qualitative methods contribute to understanding the benefits of mind-body complementary therapies.

  13. Treatment of stress fracture of the olecranon in throwing athletes with internal fixation through a small incision

    Fujioka Hiroyuki


    Full Text Available Abstract The present study is a report of retrospective case series of stress fracture of the olecranon. Six patients presented posterior elbow pain in throwing in baseball and softball, but fracture was not diagnosed in radiographs. We detected stress fracture of the olecranon using computed tomographic (CT scan and treated the patient with internal fixation with a headless cannulated double threaded screw through a small skin incision. All patients returned to competitive level without elbow complaints after the operation. When throwing athletes present with unusual posterior elbow pain and no significant findings on radiographs, a CT scan examination should be performed. We recommend surgical treatment of internal fixation with a screw through a small skin incision, as a good option for stress fracture of the olecranon in order to allow early return to sports activity in competitive athletes.

  14. The sinking of the Estonia: the effects of critical incident stress debriefing (CISD) on rescuers.

    Nurmi, L A


    On the morning of September 28, 1994 the ferry Estonia sank off the coast of Finland. The loss of life reached 852 persons, while 137 persons were rescued. This study investigated the effectiveness of Critical Incident Stress Debriefing (CISD) as a crisis intervention process. Results of this controlled investigation revealed that the CISD intervention proved effective in reducing symptoms of distress and psychological trauma as psychometrically assessed.

  15. The critical incident stress debriefing process for the Los Angeles County Fire Department: automatic and effective.

    Hokanson, M; Wirth, B


    Los Angeles County Fire Department has one of the oldest Critical Incident Stress Management (CISM) programs in the country. One core component for the LACoFD has been the Critical Incident Stress Debriefing (CISD). Two important questions for the emergency managers are: 1) Do individuals find a significant difference in symptom reduction for events that were debriefed? 2) Does helpfulness of a debriefing for a specific individual correlate with recommending the process for others? A Department-wide evaluative survey was conducted in 1996 to determine the satisfaction and effectiveness of the debriefing program. Individuals reported a significant difference in the speed of symptom reduction for incidents that were debriefed versus incidents that were not debriefed. The majority of individuals would recommend the debriefing process to others regardless of whether they personally found the process helpful or not. Based on this, the recommendations are to continue the debriefing process for specific events and to make the process mandatory; furthermore, it is recommended that the term "mandatory" be changed to "automatic." By using the term "automatic," debriefings become standard operating procedures. By doing so, a method to protect the psychological welfare of emergency personnel becomes as automatic as putting on safety protection equipment [International Journal of Emergency Mental Health, 2000, 2(4), 249-257].

  16. Thermal/moisture-related stresses and fracture behaviour in solid wood members during forced drying

    Larsen, Finn

    of wood without injury to the timber itself. When solid wood products are dried from a green condition down to an average moisture content level close to the service life conditions of the final product, significant moisture-induced stresses and related fracturing can occur. The drying stresses arise.......e. the possibility of driving mechano-sorptive strains back to their original state, was studied then by use of the verified model. Kiln-drying experiments were carried out, ina specially designed climate chamber under well-defined climatic conditions, allowing the climatic variation limits for crack initiation...... to be identified. The critical tensile stresses were determined by means of simulations and were compared with the levels of tensile strength found in tests of tensile strength carried out at the same temperature levels. Tensile strength is highly dependent upon the temperature! Water flux in the tangential...

  17. Negative magnetic resonance imaging in femoral neck stress fracture with joint effusion: a case report

    Seki, Nobutoshi; Okuyama, Koichiro; Kamo, Keiji; Chiba, Mitsuho [Akita Rosai Hospital, Department of Orthopedic Surgery, Odate, Akita (Japan); Shimada, Yoichi [Akita University School of Medicine, Department of Orthopedic Surgery, Akita (Japan)


    Femoral neck stress fracture (FNSF) is well documented in the orthopedic literature and is generally associated with strenuous activities such as long-distance running and military training. The diagnostic yield of magnetic resonance imaging (MRI) for FNSF was reported to be 100 %, and early MRI is recommended when this fracture is suspected. We encountered a 16-year-old male long-distance runner with FNSF in whom the left femoral neck showed no signal changes on MRI although an effusion was detected in the left hip joint. One month later, roentgenograms revealed periosteal callus and oblique consolidation of the left femoral neck, confirming the diagnosis of compression FNSF. Because FNSF with a normal bone marrow signal on MRI is very rare, this patient is presented here. (orig.)

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

    Anyfantis, Konstantinos


    that characterizes a given bondline, both its cohesive strength and fracture toughness material parameters must be experimentally defined. Based on these properties, failure analysis of the bondline can be done either through stress- or energy-based criteria. The aim of this work is to investigate the effectiveness...... of each criteria type to effectively predict debonding initiation/propagation of different bondlines (brittle, quasi-brittle, ductile), which are eventually utilized for the evaluation of the joint's failure load. By representing a bondline according to its cohesive length scale, an effort is made...... experimentation programme. Fracture initiation and propagation of the bondlines was numerically simulated by cohesive zone models. (C) 2014 Elsevier Ltd. All rights reserved....

  19. The effect of fracture density and stress state on the static and dynamic bulk moduli of Westerly granite

    Blake, O. O.; Faulkner, D. R.


    Elastic properties are key parameters during the deformation of rocks. They can be measured statically or dynamically, but the two measurements are often different. In this study, the static and dynamic bulk moduli (Kstatic and Kdynamic) were measured at varying effective stress for dry and fluid-saturated Westerly granite with controlled fracture densities under isotropic and differential stress states. Isotropic fracturing of different densities was induced in samples by thermal treatment to 250, 450, 650, and 850°C. Results show that fluid saturation does not greatly affect static moduli but increases dynamic moduli. Under isotropic loading, high fracture density and/or low effective pressure results in a low Kstatic/Kdynamic ratio. For dry conditions Kstatic/Kdynamic approaches 1 at low fracture densities when the effective pressure is high, consistent with previous studies. Stress-induced anisotropy exists under differential stress state that greatly affects Kstatic compared to Kdynamic. As a result, the Kstatic/Kdynamic ratio is higher than that for the isotropic stress state and approaches 1 with increasing axial loading. The effect of stress-induced anisotropy increases with increasing fracture density. A key omission in previous studies comparing static and dynamic properties is that anisotropy has not been considered. The standard methods for measuring static elastic properties, such as Poisson's ratio, Young's and shear modulus, involve subjecting the sample to a differential stress state that promotes anisotropy. Our results show that stress-induced anisotropy resulting from differential stress state is a major contributor to the difference between static and dynamic elasticity and is dominant with high fracture density.

  20. The incidence of fracture of the proximal femur in two million Canadians from 1972 to 1984. Projections for Canada in the year 2006.

    Martin, A D; Silverthorn, K G; Houston, C S; Bernhardson, S; Wajda, A; Roos, L L


    Reported increases in the number of fractures of the proximal femur in Europe are greater than can be explained by demographic changes alone. This trend was assessed in Canada by examining hospital discharge records from the provinces of Saskatchewan and Manitoba from 1972 to 1984. The annual number of first fractures of the proximal femur in persons older than 50 years of age increased 59.7% in women and 42.2% in men during this time period. In most of the five-year age groups the percentage of increase in the number of fractures exceeded the percentage of increase in population of that age group. Annual age-specific incidences (by five-year age groups) increased exponentially with age, doubling every six years, and reached a maximum value of 4% in women older than 90 years of age. Annual age-adjusted incidences increased significantly over the study period in men and women. For the whole of Canada in 1987, it is estimated that there were 13,193 first fractures of the proximal femur in women and 4610 in men, and that in the year 2006 these will rise to 22,922 and 7846, respectively. The actual increase will be considerably greater if the age-specific incidences continue to increase as they have from 1972 to 1984. The gradual decline in physical activity, which contributes to bone loss, may be one etiological factor of this trend during the last half century.

  1. Do stress fractures induce hypertrophy of the grafted fibula? A report of three cases received free vascularized fibular graft treatment for tibial defects

    Yong Qi; Hong-Tao Sun; Yue-Guang Fan; Fei-Meng Li; Zhou-Sheng Lin


    The presence of large segmental defects of the diaphyseal bone is challenging for orthopedic surgeons.Free vascularized fibular grafting (FVFG) is considered to be a reliable reconstructive procedure.Stress fractures are a common complication following this surgery,and hypertrophy is the main physiological change of the grafted fibula.The exact mechanism of hypertrophy is not completely known.To the best of our knowledge,no studies have examined the possible relationship between stress fractures and hypertrophy.We herein report three cases of patients underwent FVFG.Two of them developed stress fractures and significant hypertrophy,while the remaining patient developed neither stress fractures nor significant hypertrophy.This phenomenon indicates that a relationship may exist between stress fractures and hypertrophy of the grafted fibula,specifically,that the presence of a stress fracture may initiate the process of hypertrophy.

  2. Do stress fractures induce hypertrophy of the grafted fibula? A report of three cases received free vascularized fibular graft treatment for tibial defects.

    Qi, Yong; Sun, Hong-Tao; Fan, Yue-Guang; Li, Fei-Meng; Lin, Zhou-Sheng


    The presence of large segmental defects of the diaphyseal bone is challenging for orthopedic surgeons. Free vascularized fibular grafting (FVFG) is considered to be a reliable reconstructive procedure. Stress fractures are a common complication following this surgery, and hypertrophy is the main physiological change of the grafted fibula. The exact mechanism of hypertrophy is not completely known. To the best of our knowledge, no studies have examined the possible relationship between stress fractures and hypertrophy. We herein report three cases of patients underwent FVFG. Two of them developed stress fractures and significant hypertrophy, while the remaining patient developed neither stress fractures nor significant hypertrophy. This phenomenon indicates that a relationship may exist between stress fractures and hypertrophy of the grafted fibula, specifically, that the presence of a stress fracture may initiate the process of hypertrophy.

  3. A cross-sectional study of the effects of load carriage on running characteristics and tibial mechanical stress: implications for stress fracture injuries in women


    Orthop Surg. 2000;8(6):344–53. 3. Brukner P, Bradshaw C, Khan KM, White S, Crossley K. Stress fractures: a review of 180 cases. Clin J Sport Med. 1996;6(2...85–9. 4. Fredericson M, Bergman AG, Hoffman KL, Dillingham MS. Tibial stress reaction in runners. Correlation of clinical symptoms and scintigraphy... Stress fracture risk factors in basic combat training. Int J Sports Med. 2012;33(11):940–6. doi:10. 1055/s-0032-1311583. 6. Jones BH, Perrotta DM

  4. A survey of experience-based preference of Nickel-Titanium rotary files and incidence of fracture among general dentists

    WooCheol Lee


    Full Text Available Objectives The purpose was to investigate the preference and usage technique of NiTi rotary instruments and to retrieve data on the frequency of re-use and the estimated incidence of file separation in the clinical practice among general dentists. Materials and Methods A survey was disseminated via e-mail and on-site to 673 general dentists. The correlation between the operator's experience or preferred technique and frequency of re-use or incidence of file fracture was assessed. Results A total of 348 dentists (51.7% responded. The most frequently used NiTi instruments was ProFile (39.8% followed by ProTaper. The most preferred preparation technique was crown-down (44.6%. 54.3% of the respondents re-used NiTi files more than 10 times. There was a significant correlation between experience with NiTi files and the number of reuses (p = 0.0025. 54.6% of the respondents estimated experiencing file separation less than 5 times per year. The frequency of separation was significantly correlated with the instrumentation technique (p = 0.0003. Conclusions A large number of general dentists in Korea prefer to re-use NiTi rotary files. As their experience with NiTi files increased, the number of re-uses increased, while the frequency of breakage decreased. Operators who adopt the hybrid technique showed less tendency of separation even with the increased number of re-use.

  5. Effects of laser heat treatment on the fracture morphologies of X80 pipeline steel welded joints by stress corrosion

    De-jun Kong; Cun-dong Ye


    The surfaces of X80 pipeline steel welded joints were processed with a CO2 laser, and the effects of laser heat treatment (LHT) on H2S stress corrosion in the National Association of Corrosion Engineers (NACE) solution were analyzed by a slow strain rate test. The frac-ture morphologies and chemical components of corrosive products before and after LHT were analyzed by scanning electron microscopy and energy-dispersive spectroscopy, respectively, and the mechanism of LHT on stress corrosion cracking was discussed. Results showed that the fracture for welded joints was brittle in its original state, while it was transformed to a ductile fracture after LHT. The tendencies of hydro-gen-induced corrosion were reduced, and the stress corrosion sensitivity index decreased from 35.2%to 25.3%, indicating that the stress corrosion resistance of X80 pipeline steel welded joints has been improved by LHT.

  6. Critical incident stress management (CISM): benefit or risk for emergency services?

    Bledsoe, Bryan E


    Critical incident stress management (CISM) has become a common practice in modern emergency services. Described in 1983 as critical incident stress debriefing (CISD), CISM was originally marketed to help emergency personnel deal with ostensibly stressful situations they would encounter as a part of their work. To review the status of the medical and psychological literature regarding the efficacy and safety of CISM. Several pertinent databases were accessed and searched for scientific articles pertaining to CISM. These were subsequently analyzed for methodology and pertinence to the study topic. Numerous scientific articles were found concerning CISM. Several high-quality studies were identified, but many other studies lacked adequate methodology sufficient for use in an evidence-based medicine approach. Others were from trade magazines, non-refereed journals, and obscure mental health journals. Several meta-analyses and randomized controlled trials (RCTs) were found. Overall, these studies show that, at best, CISM has no effect on preventing psychiatric sequelae following a traumatic event, particularly post-traumatic stress disorder (PTSD). Furthermore, several studies report possible paradoxical worsening of stress-related symptoms in patients and personnel receiving CISM. Despite the limitations of the existing literature base, several meta-analyses and RCTs found CISM to be ineffective in preventing PTSD. Several studies found possible iatrogenic worsening of stress-related symptoms in persons who received CISM. Because of this, CISM should be curtailed or utilized only with extreme caution in emergency services until additional high-quality studies can verify its effectiveness and provide mechanisms to limit paradoxical outcomes. It should never be a mandatory intervention.

  7. The effects of residual stress, viscoelastic and thermodynamic parameters on apparent fracture toughness of dental bilayer ceramic composites

    Taskonak, Burak

    Bilayer dental ceramic composites used for fixed partial dentures are becoming more widely used in dental practices because of their biocompatibility, aesthetic properties, and chemical durability. However, large statistical variations in the strength of ceramics are associated with the structural flaws as a result of processing and complex stress states within the surfaces of the materials because of thermal properties of each layer. In addition, partial delaminations of the veneer layer and connector fractures of bilayer ceramic fixed partial dentures (FPDs) have been observed in a clinical study which is a part of this dissertation. Analysis of fracture surfaces of failed FPDs reveals that such fractures of the veneering ceramic are most likely caused by lateral crack growth. Global residual stresses associated with the coefficient of thermal expansion differences between core and veneering ceramics can cause lateral crack initiation. Also, rapid cooling of bilayer ceramics from the sintering temperature of the glass veneer may not allow the interfacial stresses in the viscoelastic glass to relax to equilibrium values. This can further contribute to the propagation of lateral cracks. Furthermore, local residual stresses that develop in the plastic deformation zone below sharp contact areas on the occlusal surface are another contributor to lateral crack growth. Superposition of global residual stresses and a Boussinesq stress field can incrementally increase the possibility of lateral crack growth. The long-range goals of this study are to critically analyze the lateral crack growth mechanisms associated with residual stresses, to modify residual tensile stress distributions by controlled heat treatment, and to minimize the probability of veneering ceramic fractures. Four approaches were used to accomplish these goals: (1) clinical evaluation of a bilayer ceramic fixed partial denture system; (2) fracture surface analysis of clinically failed FPDs; (3


    Kulkarni; Mangesh Rajput; Kiran Gaonkar; Nitin Patil; Nishant Gaonkar; Ketan Gupta; Nirav Patel; Ayush Lal


    Colles‟ fracture is confined to adult and usually is seen in women over the age of fifty who have fallen on the outstretched hand. EPL tendon is the most common extensor tendon to rupture after colles‟ fracture. To our belief the incidenc e of median nerve injury and EPL tendon rupture given in literature are much higher than what we see now a days, so with this aim we carried this study to find out the true incidence of CTS and EPL tendon rupture in Indian population. AI...

  9. Maximum length of large diameter Czochralski silicon single crystals at fracture stress limit of seed

    Kim, K. M.; Smetana, P.


    Growth of large diameter Czochralski (CZ) silicon crystals require complete elimination of dislocations by means of Dash technique, where the seed diameter is reduced to a small size typically 3 mm in conjunction with increase in the pull rate. The maximum length of the large CZ silicon is estimated at the fracture stress limit of the seed neck diameter ( d). The maximum lengths for 200 and 300 mm CZ crystals amount to 197 and 87 cm, respectively, with d = 0.3 cm; the estimated maximum weight is 144 kg.

  10. Scaphoid Stress Fracture in High-Level Gymnast: A Case Report

    J. C. Nakamoto


    Full Text Available We present the case of an 18-year-old high-level gymnast who sustained a stress fracture of the scaphoid associated with a distal radial epiphysiolysis. Clinical evaluation demonstrated decreased range of motion of the affected wrist and insidious pain on the snuffbox and tenderness on the distal radial physis. He was submitted to surgical treatment with scaphoid percutaneous fixation and radial styloid process in situ fixation. Clinical features improved, and he got back to competition 6 months after surgery without symptoms and with complete range of motion.

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

    Bo Zhang


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

  12. Serum 25-Hydroxyvitamin D Levels and Stress Fractures in Military Personnel: A Systematic Review and Meta-analysis.

    Dao, Dyda; Sodhi, Sukhmani; Tabasinejad, Rasam; Peterson, Devin; Ayeni, Olufemi R; Bhandari, Mohit; Farrokhyar, Forough


    Low serum 25-hydroxyvitamin D (25(OH)D) levels have been associated with stress fractures in various physically active populations such as the military. To examine the association between serum 25(OH)D levels and stress fractures in the military. Systematic review and meta-analysis. Relevant studies were identified through searching multiple databases and manually screening reference lists. Two reviewers independently selected the included studies by applying the eligibility criteria to the title, abstract, and/or full text of the articles yielded in the search. Two reviewers also independently conducted the methodological quality assessment and data extraction. A random-effects model was used to calculate the mean difference (MD) with 95% CI in serum 25(OH)D levels between stress fracture cases and controls. Nine observational studies on lower extremity stress fractures were eligible, and 1 was excluded due to inadequate data. A total of 2634 military personnel (age, 18-30 years; 44% male) with 761 cases (16% male) and 1873 controls (61% male) from 8 studies were included in the analysis. Three of the 8 studies measured serum 25(OH)D levels at the time of stress fracture diagnosis, and the 5 remaining studies measured serum 25(OH)D levels at the time of entry into basic training. The mean serum 25(OH)D level was lower in stress fracture cases than in controls at the time of entry into basic training (MD, -2.63 ng/mL; 95% CI, -5.80 to 0.54; P = .10; I(2) = 65%) and at the time of stress fracture diagnosis (MD, -2.26 ng/mL; 95% CI, -3.89 to -0.63; P = .007; I(2) = 42%). Despite the inherent limitations of the included studies, the study results suggest some association between low serum 25(OH)D levels and lower extremity stress fractures in military personnel. Given the rigorous training of military personnel, implementing strategies to ensure sufficient 25(OH)D levels may be beneficial for reducing the risk of stress fractures. © 2014 The Author(s).

  13. Serum Levels of a Cathepsin-K Generated Periostin Fragment Predict Incident Low-Trauma Fractures in Postmenopausal Women Independently of BMD and FRAX.

    Bonnet, Nicolas; Biver, Emmanuel; Chevalley, Thierry; Rizzoli, René; Garnero, Patrick; Ferrari, Serge L


    Periostin is a matricellular protein involved in bone formation and bone matrix organization, but it is also produced by other tissues. Its circulating levels have been weakly associated with bone microstructure and prevalent fractures, possibly because periostin measured by the current commercial assays does not specifically reflect bone metabolism. In this context, we developed a new ELISA for a periostin fragment resulting from cathepsin K digestion (K-Postn). We hypothesized that circulating K-Postn levels could be associated with bone fragility. A total of 695 women (age 65.0 ± 1.5 years), enrolled in the Geneva Retirees Cohort (GERICO), were prospectively evaluated over 4.7 ± 1.9 years for the occurrence of low-trauma fractures. At baseline, we measured serum periostin, K-Postn, and bone turnover markers (BTMs), distal radius and tibia microstructure by HR-pQCT, hip and lumbar spine aBMD by DXA, and estimated fracture probability using the Fracture Risk Assessment Tool (FRAX). Sixty-six women sustained a low-trauma clinical fracture during the follow-up. Total periostin was not associated with fractures (HR [95% CI] per SD: 1.19 [0.89 to 1.59], p = 0.24). In contrast, K-Postn was significantly higher in the fracture versus nonfracture group (57.5 ± 36.6 ng/mL versus 42.5 ± 23.4 ng/mL, p K-Postn remained significantly associated with fracture risk. The performance of the fracture prediction models was improved by adding K-Postn to aBMD or FRAX (Harrell C index for fracture: 0.70 for aBMD + K-Post versus 0.58 for aBMD alone, p = 0.001; 0.73 for FRAX + K-Postn versus 0.65 for FRAX alone, p = 0.005). Circulating K-Postn predicts incident fractures independently of BMD, BTMs, and FRAX in postmenopausal women. Hence measurement of a periostin fragment resulting from in vivo cathepsin K digestion may help to identify subjects at high risk of fracture. © 2017 American Society for Bone and Mineral Research. © 2017

  14. Elastic stress transmission and transformation (ESTT) by confined liquid: A new mechanics for fracture in elastic lithosphere of the earth

    Xu, Xing-Wang; Peters, Stephen; Liang, Guang-He; Zhang, Bao-Lin


    We report on a new mechanical principle, which suggests that a confined liquid in the elastic lithosphere has the potential to transmit a maximum applied compressive stress. This stress can be transmitted to the internal contacts between rock and liquid and would then be transformed into a normal compressive stress with tangential tensile stress components. During this process, both effective compressive normal stress and tensile tangential stresses arise along the liquid–rock contact. The minimum effective tensile tangential stress causes the surrounding rock to rupture. Liquid-driven fracture initiates at the point along the rock–liquid boundary where the maximum compressive stress is applied and propagates along a plane that is perpendicular to the minimum effective tensile tangential stress and also is perpendicular to the minimum principal stress.

  15. Stress-wave induced fracture of unidirectional composites: an experimental study using digital image correlation method

    Lee, Dongyeon; Tippur, Hareesh V.


    In this work, fracture behavior of unidirectional graphite/epoxy composite materials is optically investigated. Single-edge notched coupons are studied under geometrically symmetric impact loading. The notch orientation parallel to or at an angle relative to the fiber orientation is considered to produce mode-I as well as mixed-mode fracture. Stress-wave induced crack initiation and rapid crack growth events are studied using a digital correlation technique and high-speed photography. Surface deformations histories in the crack-tip vicinity are obtained by analyzing decorated speckle recordings. Measured deformation fields are used to extract fracture parameters and examine the effect of fiber orientation on crack initiation and growth behaviors. The maximum crack speed observed is the highest for mode-I dominant conditions and decreases with increasing fiber orientation angle. With increasing fiber orientation angle, crack takes longer to attain the maximum speed upon initiation. The crack initiation toughness values decrease with increasing degree-of-anisotropy.

  16. A geometrically based method for predicting stress-induced fracture aperture and flow in discrete fracture networks

    Bisdom, Kevin; Bertotti, Giovanni; Nick, Hamid


    on subsurface fracture aperture, which is essential for quantifying porosity and permeability. Apertures are difficult to obtain from either outcropping or subsurface data and are therefore often based on fracture size or scaling relationships, but these do not consider the orientation and spatial distribution...

  17. Group critical incident stress debriefing with emergency services personnel: a randomized controlled trial.

    Tuckey, Michelle R; Scott, Jill E


    Although single-session individual debriefing is contraindicated, the efficacy of group psychological debriefing remains unresolved. We conducted the first randomized controlled trial of critical incident stress debriefing (CISD) with emergency workers (67 volunteer fire-fighters) following shared exposure to an occupational potentially traumatic event (PTE). The goals of group CISD are to prevent post-traumatic stress and promote return to normal functioning following a PTE. To assess both goals we measured four outcomes, before and after the intervention: post-traumatic stress, psychological distress, quality of life, and alcohol use. Fire brigades were randomly assigned to one of three treatment conditions: (1) CISD, (2) Screening (i.e., no-treatment), or (3) stress management Education. Controlling for pre-intervention scores, CISD was associated with significantly less alcohol use post-intervention relative to Screening, and significantly greater post-intervention quality of life relative to Education. There were no significant effects on post-traumatic stress or psychological distress. Overall, CISD may benefit broader functioning following exposure to work-related PTEs. Future research should focus on individual, group, and organizational factors and processes that can promote recovery from operational stressors. Ultimately, an occupational health (rather than victim-based) approach will provide the best framework for understanding and combating potential threats to the health and well-being of workers at high risk for PTE exposure.

  18. Development of joints and shear fractures in the Kuqa depression and its implication to regional stress field switching

    ZHANG; Zhongpei; WANG; Qingchen


    The superimposed basin must have undergone the changes of regional stress field. Study on the nature and switch of regional stress field of superimposed basin is very useful to understanding its stress state and tectonic events during its formation and evolution. As sensitive markers of small stress changes, joint and shear fracture, characterized by consistency of orientation over wide area, can be used to reconstruct paleostress state and its evolution. Detailed observations and analysis on the orientations, geometrical patterns, sequences of joints and shear fractures and their chronological relation to faults and folds show that, the NEE-SWW systematic joints and NNW-SSE systematic joints developed in the Mesozoic and Cenozoic strata are much more prominent than NW-SE systematic joints and shear fractures with different orientations. And the NWW-SEE and NW-SE systematic joints formed later than NEE-SWW systematic joints but earlier than shear fractures with different orientations. According to the relationships between joint and shear fractures and stress, the NEE-SWW systematic joints are inferred to result from lateral weak extension caused by the late Cretaceous regional uplift, while the NNW-SSE and NW-SE systematic joints are interpreted as syn-tectonic deformation relating to strong N-S compression in the Neogene. But some conjugate shear fractures occur probably due to sinistral strike-slip faulting in the Kuqa depression. At the beginning of the Neogene, the stress field changed and the maximal principal stress σ1 switched from vertical to horizontal.

  19. A Randomized Controlled Trial of an Adapted Form of Individual Critical Incident Stress Debriefing for Victims of an Armed Robbery

    Marchand, Andre; Guay, Stephane; Boyer, Richard; Iucci, Soledad; Martin, Annick; St-Hilaire, Marie-Helene


    Victims of an armed robbery are at great risk of psychological distress. This research is a prospective randomized controlled clinical trial of an adapted form of Critical Incident Stress Debriefing (CISD...

  20. Hip fracture in hospitalized medical patients

    Zapatero Antonio


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

  1. Experimental study on time-dependent stress and strain of in-plane shear(ModeⅡ) fracture process of rock

    王志; 饶秋华; 谢海峰


    Shear-box test with strain measurement was used to study time-dependent stress and strain of in-plane shear(Mode Ⅱ) fracture process of rock and to reveal the mechanism of Mode Ⅱ fracture.Numerical results show that the maximum shear stress τmax at the crack tip is much larger than the maximum tensile stress σ1 and the ratio of τmax/σ1 is about 5,which favors Mode Ⅱ fracture of rock.Test results indicate that the strain-time curve comprises three stages:the linear deformation stage,the micro-cracking stage and the macroscopic crack propagation.The strain in the direction of the original notch plane is negative,due to restraining effect of compressive loading applied to the original notch plane.Both σ1 and τmax are increased as the load increases,but the slope of τmax is larger than that of σ1 and the value of τmax is always larger than that of σ1.Therefore,τmax reaches its limited value at peak load before σ1 and results in Mode Ⅱ fracture of rock.Shear-box(i.e.compression-shear) test becomes a potential standard method for achieving the true Mode Ⅱ fracture and determining Mode Ⅱ fracture toughness of rock.

  2. Tectonic Stress Wave,Micro-fracture Wave,and a Modified Elastic-Rebound Model of Earthquakes

    Zhao Fuyuan


    Based on a sample of some real earthquakes,we have suggested in previous papers that there is a density-tectonic stress wave with ultra-low frequency which is emitted from the epicenter region for months before earthquakes,and a micro-fracture wave 1~10 days before earthquakes.The former has been observed by different kinds of measurements and the latter has been observed by a few chance observations which consists of electromagnetic,gravitational and sonic fluctuations.We show real observational results that depict the two waves and they have very different frequencies,which are not difficult to discriminate.The classicaI elastic-rebound model is one of the most influential theories on earthquakes,and the thermodynamic elastic-rebound model has amended the classical framework.Considering the two waves above,we attempt to further modify the elasticrebound model,and the new framework could be called the"micro-fracture elasticrebound model".We infer that tectonic earthquakes could have three special phases:the accumulation of tectonic stress,micro-fracture,and main-fracture.Accordingly,there would be three waves which come from the epicenter of a tectonic earthquake,i.e.,the tectonic stress wave with ultra-low frequency a few months before the earthquake,the micro-fracture wave about 1~10 days before the earthquake and the main-fracture wave(common earthquake wave).

  3. Growth Plate Fractures

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

  4. Incidence and costs of hip fractures vs strokes and acute myocardial infarction in Italy: comparative analysis based on national hospitalization records

    Piscitelli P


    Full Text Available Prisco Piscitelli,1,2 Giovanni Iolascon,3 Alberto Argentiero,2 Giovanna Chitano,2 Cosimo Neglia,2 Gemma Marcucci,1 Manuela Pulimeno,2 Marco Benvenuto,2 Santa Mundi,2 Valentina Marzo,2 Daniela Donato,4 Angelo Baggiani,4 Alberto Migliore,5 Mauro Granata,6 Francesca Gimigliano,3 Raffaele Di Blasio,7 Alessandra Gimigliano,3 Lorenzo Renzulli,7 Maria Luisa Brandi,1 Alessandro Distante,2,4 Raffaele Gimigliano3,71University of Florence, Florence Italy; 2ISBEM Research Centre, Brindisi, Italy; 3Second University of Naples, Naples, Italy; 4University of Pisa, Pisa, Italy; 5Fatebenefratelli St Peter’s Hospital, Rome, Italy; 6St Filippo Neri Hospital, Rome, Italy; 7Casa di Cura Santa Maria del Pozzo, Somma Vesuviana, ItalyObjectives: As osteoporotic fractures are becoming a major health care problem in countries characterized by an increasing number of older adults, in this study we aimed to compare the incidence and costs of hip fragility fractures in Italian elderly people versus those of major cardiovascular diseases (strokes and acute myocardial infarctions [AMI] occurring in the whole adult population.Methods: We analyzed hospitalization records maintained at the national level by the Italian Ministry of Health for the diagnosis of hip fractures (ICD-9-CM codes 820–821, AMI (code 410, hemorrhagic (codes 430, 431, 432 and ischemic strokes (codes 433–434, and TIA (code 435 between 2001–2005. Cost analyses were based on diagnosis-related groups.Results: The incidence of hip fractures in elderly people has increased (+12.9% between 2001 and 2005, as well as that of AMI (+20.2% and strokes (hemorrhagic: +9.6%; ischemic: +14.7 occurring in the whole adult population; conversely, hospitalization due to TIA decreased by a rate of 13.6% between 2001 and 2005. In 2005, the hospital costs across the national health care system that were associated with hip fragility fractures in the elderly were comparable to those of strokes (both hemorrhagic and

  5. Group process research and emergence of therapeutic factors in critical incident stress debriefing.

    Pender, Debra A; Prichard, Karen K


    Critical incident stress debriefing is a highly utilized and often debated form of post-trauma exposure intervention. This article presents exploratory group process research that utilized a mixed method approach and group process research techniques. The article's findings, the emergence of therapeutic factors, support that CISD group work does yield indicators consistent with support/ psychoeducation groups with a crisis theme. Further the events that trigger the intervention yield specific therapeutic factors. CISD group work may be better understood through established group research patterns.

  6. The effect of social deprivation on hip fracture incidence in England has not changed over 14 years: an analysis of the English Hospital Episodes Statistics (2001-2015).

    Bhimjiyani, A; Neuburger, J; Jones, T; Ben-Shlomo, Y; Gregson, C L


    Deprivation predicts increased hip fracture risk. Over 14 years, hip fracture incidence increased among men with persisting inequalities. Among women, inequalities in incidence were less pronounced; whilst incidence decreased overall, this improvement was seen marginally less in women from the most deprived areas. Hip fracture prevention programmes have not reduced inequalities. Deprivation is associated with increased hip fracture risk. We examined the effect of area-level deprivation on hip fracture incidence in England over 14 years to determine whether inequalities have changed over time. We used English Hospital Episodes Statistics (2001/2002-2014/2015) to identify hip fractures in adults aged 50+ years and mid-year population estimates (2001-2014) from the Office for National Statistics. The Index of Multiple Deprivation measured local area deprivation. We calculated age-adjusted incidence rate ratios (IRR) for hip fracture, stratified by gender and deprivation quintiles. Over 14 years, we identified 747,369 hospital admissions with an index hip fracture; the number increased from 50,640 in 2001 to 55,092 in 2014; the proportion of men increased from 22.2% to 29.6%. Whereas incidence rates decreased in women (annual reduction 1.1%), they increased in men (annual increase 0.6%) (interaction p deprived areas, particularly among men: IRR most vs. least deprived quintile 1.50 [95% CI 1.48, 1.52] in men, 1.17 [1.16, 1.18] in women. Age-standardised incidence increased for men across all deprivation quintiles from 2001 to 2014. Among women, incidence fell more among those least compared to most deprived (year by deprivation interaction p Deprivation is a stronger relative predictor of hip fracture incidence in men than in women. However, given their higher hip fracture incidence, the absolute burden of deprivation on hip fractures is greater in women. Despite public health efforts to prevent hip fractures, the health inequality gap for hip fracture incidence

  7. Pressure Transient Analysis and Flux Distribution for Multistage Fractured Horizontal Wells in Triple-Porosity Reservoir Media with Consideration of Stress-Sensitivity Effect

    Jingjing Guo


    Full Text Available Triple-porosity model is usually adopted to describe reservoirs with multiscaled pore spaces, including matrix pores, natural fractures, and vugs. Multiple fractures created by hydraulic fracturing can effectively improve the connectivity between existing natural fractures and thus increase well deliverability. However, little work has been done on pressure transient behavior of multistage fractured horizontal wells in triple-porosity reservoirs. Based on source/sink function method, this paper presents a triple-porosity model to investigate the transient pressure dynamics and flux distribution for multistage fractured horizontal wells in fractured-vuggy reservoirs with consideration of stress-dependent natural fracture permeability. The model is semianalytically solved by discretizing hydraulic fractures and Pedrosa’s transformation, perturbation theory, and integration transformation method. Type curves of transient pressure dynamics are generated, and flux distribution among hydraulic fractures for a fractured horizontal well with constant production rate is also discussed. Parametric study shows that major influential parameters on transient pressure responses are parameters pertinent to reservoir properties, interporosity mass transfer, and hydraulic fractures. Analysis of flux distribution indicates that flux density gradually increases from the horizontal wellbore to fracture tips, and the flux contribution of outermost fractures is higher than that of inner fractures. The model can also be extended to optimize hydraulic fracture parameters.

  8. The potential for spills and leaks of hydraulic fracturing related fluids on well sites and from road incidents.

    Clancy, Sarah; Worrall, Fred; Davies, Richard; Gluyas, Jon


    recovered. The most common cause of leakage each year is equipment failure; these results highlight the need for good regulation and maintenance onsite. The UK's Institute of Directors suggests several shale gas production scenarios for the UK and how this would influence truck movement. One of their scenarios suggests the development of well pads with 10-wells and 40 laterals (one well pad with 10 well each with 4 laterals). This type of well pad would be projected to use 544,000 m3 of water, which would generate between 11155-31288 truck movements over 20 years, or 6.1-17.1 per day if averaged over 5 years. Dairy farmers in the UK produce 11 million m3 of milk a year, which if the tanker has a capacity of 30 m3, equates to approximately 366667 milk tanker journeys a year. This study assesses the number of road incidents and milk tanker spills and predicts the likelihood of such events for fluids involved in hydraulic fracturing.

  9. New development of hydraulic fracturing technique for in-situ stress measurement at great depth of mines


    In-situ stress measurement using the hydraulic fracturing technique was made at Wanfu Coal Mine in Shandong Province,China.To solve problems caused by great measuring depth and extra thick overburden soil layers in the mine,a series of improved techniques were developed for the traditional hydraulic fracturing technique and equipment to increase their pressure-enduring ability and to ensure safe and flexible removal of the sealing packers with other experimental apparatus.Successful in-situ stress measurement at 37 points within 7 boreholes,which were mostly over 1000 m deep,was completed.Through the measurement,detailed in




    Full Text Available Ground water is considered to be the best safe protected drinking water source and bore wells are drilled in hard crystalline rock terrains for drinking water, irrigation and industrial purposes. Even after scientific location, some bore wells yield inadequate quantity of water or fail to yield. The success of bore wells depend largely onnumber, length, dilation and interconnectivity of fractures encountered on drilling. Considering the cost factor involved in drilling a new bore well, rejuvenation of failed bore well through some technique is thought off. The innovative technology of ‘hydro fracturing’ is a new interdisciplinary approach of Hydro mechanical tostimulate the bore well to improve the yield by applying water pressure into bore well by using a heavy duty mechanical compressor. The hydro fracturing technique was first used in oil well to increase oil and gas production. In this research paper, the hydraulic pressure applied increases with depth reflecting the rigidness,toughness of rock. The fracture development, propagation of fracture and stress behavior depends on the physical and mechanical properties of rocks. The hydro fracturing process has been conducted in three depth zones ranging from 8 m to 45 m below ground level in Annavasal union of Pudukottai district, Tamil Nadu, India. The Pressure application varies depending on the geological formations. This study pertains to a part of research work. The minimum and maximum pressures applied are 1 and 10 N/mm2 respectively. The maximumpressure of 10 N/mm2 has been recorded in the third zone, where the country rock is charnockite which is generally massive, compact and dense rock. Generally for the igneous rock in the third zone in the depth range of 40 to 50 m, more than 7 N/mm2 of pressure has been applied indicating extremely strong nature with uniaxial compressive strength 100 – 300 N/mm2, tensile strength 7- 25 N/mm2. Out of 37 bore wells 32.4% of bore wells have shown

  11. Study of stress adaptability of fracture healing%骨折愈合的应力适应性研究

    董福慧; 关继超; 赵勇; 邹炳曾; 尚天裕


    目的 探讨骨折端受力、肌肉动力、骨痂密度与骨折愈合的关系。方法 通过传感器电测技术与X线灰度分析的方法,从三个方面对骨折愈合的应力适应性进行了研究:①分别对14只1岁龄山羊进行了断端受力与骨折愈合的关系的研究;②对10只健康成年家兔进行了肌肉动力与骨折愈合的关系的研究;③对56只健康成年家兔进行了骨痂密度与骨折愈合的关系的研究。结果与结论 ①理想的骨折愈合与最佳的应力状态相适应;②肌肉动力是应力适应的反馈调节因素;③骨痂密度是应力适应的反馈结果。%Objective To explore the relationship between local stress status,muscular motivation,callus density and fracture healing.Methods Stress adaptability of fracture healing was studied from three respects:1.the relationship between fracture local stress and fracture healing was studied in 14 one year old goats;2.the relationship between muscular motivation and fracture healing was studied in 10 health adult rabbits and 3.the relationship between callus density and fracture healing was studied in 56 healthy adult rabbits.Electric transducer technique and X-ray densitometry method were used in all the three groups of animals.Results and Conclusion 1.Ideal fracture healing should be adapted to the best stress status;2.Muscular motivation is the biofeedback regulation factor of stress adaptability of fracture healing;3.The density of callus is the result of biofeedback of stress adaptability of fracture healing.

  12. The effectiveness of critical incident stress debriefing with primary and secondary trauma victims.

    Jacobs, Julie; Horne-Moyer, H Lynn; Jones, Rebecca


    Critical incident stress debriefing (CISD) (Mitchell, 1983) has been under intense scrutiny recently in the psychology literature. Several authors have concluded that CISD has no effect or even negative effects on victims of trauma (Bisson, McFarlane, & Rose, 2000; van Emmerik, Kamphuis, Hulsbosch, & Emmelkamp, 2002). This review calls these conclusions into question by critically contrasting: (1) studies that utilize CISD with emergency services personnel ("secondary" victims of trauma, for whom the CISD and the larger Critical Incident Stress Management models were first created) and (2) studies that utilize CISD with primary victims of trauma. This review suggests that CISD is an effective method of reducing risk for PTSD-related symptoms in emergency services personnel. However, when debriefings are conducted with primary victims of traumatic events (e.g., accident victims, burn victims still in the hospital), the results are much less promising. The authors conclude that protocols are needed for interventions with primary victims to help mitigate the impact of trauma on this population. Appropriate interventions might include risk assessment and appropriate referral services, or in some instances, focused psycho-educational group debriefings. Further research is clearly warranted to examine the effectiveness of alternative interventions for the primary victim population.

  13. On the determination of stress profiles in expanded austenite by grazing incidence X-ray diffraction and successive layer removal

    Fernandes, Frederico Augusto Pires; Christiansen, Thomas L.; Winther, Grethe


    Surface layers of expanded austenite resulting from nitriding typically exhibit large gradients in residual stress and composition. Evaluation of residual-stress profiles is explored by means of grazing incidence X-ray diffraction (GI-XRD), probing shallow depths, combined with successive layer r...

  14. Treatment incidence of and medical utilization for hospitalized subjects with pathologic fractures in Taiwan-Survey of the 2008 National Health Insurance data

    Phan Dinh-Van


    Full Text Available Abstract Background Almost all studies of pathologic fractures have been conducted based on patients with tumours and hospital-based data; however, in the present study, a nationwide epidemiological survey of pathologic fractures in Taiwan was performed and the medical utilization was calculated. Methods All claimants of Taiwan's National Health Insurance (NHI Program in 2008 were included in the target population of this descriptive cross-sectional study. The registration and inpatient expenditure claims data by admission of all hospitalized subjects of the target population were examined and the concomitant International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM diagnosis codes were evaluated and classified into seven major categories of fracture. Results A total of 5,244 incident cases of pathologic fracture were identified from the 2008 hospitalized patient claims data. The incidence of pathologic fracture of the humerus, distal radius/ulna, vertebrae, femoral neck, other part of the femur, and tibia/fibula was 0.67, 0.08, 10.58, 1.11, 0.56, and 0.11 per 100,000 people, respectively, and patients with those fractures were hospitalized for 43.9 ± 42.9, 31.1 ± 32.9, 29. 4 ± 34.4, 43.3 ± 41.2, 42.4 ± 38.1, and 42.0 ± 32.8 days, respectively, incurring an average medical cost of US$11,049 ± 12,730, US$9,181 ± 12,115, US$6,250 ± 8,021, US$9,619 ± 8,906, US$10,646 ± 11,024, and US$9,403 ± 9,882, respectively. The percentage of patients undergoing bone surgery for pathologic fracture of the humerus, radius/ulna, vertebrae, femoral neck, other part of the femur, and tibia/fibula was 31.2%, 44.4%, 11.3%, 46.5%, 48.4%, and 52.5% respectively. Conclusions Comparing Taiwan to other countries, this study observed for Taiwan higher medical utilization and less-aggressive surgical intervention for patients hospitalized with pathologic fractures.

  15. A retrospective cohort study on the influence of UV index and race/ethnicity on risk of stress and lower limb fractures

    Montain, Scott J; McGraw, Susan M.; Ely, Matthew R.; Grier, Tyson L; Knapik, Joseph J.


    Background Low vitamin D status increases the risk of stress fractures. As ultraviolet (UV) light is required for vitamin D synthesis, low UV light availability is thought to increase the risk of vitamin D insufficiency and poor bone health. The purpose of this investigation was to determine if individuals with low UV intensity at their home of record (HOR) or those with darker complexions are at increased risk of developing stress fractures and lower limb fractures during U.S. Army Basic Com...

  16. The concept of the average stress in the fracture process zone for the search of the crack path

    Yu.G. Matvienko


    Full Text Available The concept of the average stress has been employed to propose the maximum average tangential stress (MATS criterion for predicting the direction of fracture angle. This criterion states that a crack grows when the maximum average tangential stress in the fracture process zone ahead of the crack tip reaches its critical value and the crack growth direction coincides with the direction of the maximum average tangential stress along a constant radius around the crack tip. The tangential stress is described by the singular and nonsingular (T-stress terms in the Williams series solution. To demonstrate the validity of the proposed MATS criterion, this criterion is directly applied to experiments reported in the literature for the mixed mode I/II crack growth behavior of Guiting limestone. The predicted directions of fracture angle are consistent with the experimental data. The concept of the average stress has been also employed to predict the surface crack path under rolling-sliding contact loading. The proposed model considers the size and orientation of the initial crack, normal and tangential loading due to rolling–sliding contact as well as the influence of fluid trapped inside the crack by a hydraulic pressure mechanism. The MATS criterion is directly applied to equivalent contact model for surface crack growth on a gear tooth flank.

  17. A model for a statewide critical incident stress (CIS) debriefing program for emergency services personnel.

    Neely, K W; Spitzer, W J


    Emergency services personnel are highly vulnerable to acute and cumulative critical incident stress (CIS) that can manifest as anger, guilt, depression, and impaired decision-making, and, in certain instances, job loss. Interventions designed to identify such distress and restore psychological functioning becomes imperative. A statewide debriefing team was formed in 1988 through a collaborative effort between an academic department of emergency medicine and a social work department of a teaching hospital, and a metropolitan area fire department and ambulance service. Using an existing CIS debriefing model, 84 prescreened, mental health professionals and emergency services personnel were provided with 16 hours of training and were grouped into regional teams. Debriefing requests are received through a central number answered by a communicator in a 24-hour communications center located within the emergency department. Debriefings are conducted 48-72 hours after the event for specific types of incidents. Follow-up telephone calls are made by the debriefing team leader two to three weeks following a debriefing. The teams rely on donations to pay for travel and meals. One hundred sixty-eight debriefings were conducted during the first four years. Rural agencies accounted for 116 (69%) requests. During this period, 1,514 individuals were debriefed: 744 (49%) firefighters, 460 (30%) EMTs, and 310 (21%) police officers, dispatchers, and other responders. Deaths of children, extraordinary events, and incidents involving victims known to the responders (35%, 14%, and 14% respectively) were the most common reasons for requesting debriefings. Feedback was received from 48 (28%) of the agencies that requested the debriefing. All of those who responded felt that the debriefing had a beneficial effect on its personnel. Specific individuals identified by agency representatives as having the greatest difficulty were observed to be returned to their pre-incident state. CIS

  18. Stress analysis and optimization of Nd:YAG pulsed laser processing of notches for fracture splitting of a C70S6 connecting rod

    Kou, Shuqing; Gao, Yan; Zhao, Yong; Lin, Baojun [Jilin University, Changchun (China)


    The pulsed laser pre-processing of a notch as the fracture initiation source for the splitting process is the key mechanism of an advanced fracture splitting technology for C70S6 connecting rods. This study investigated the stress field of Nd:YAG pulsed laser grooving, which affects the rapid fracture initiation at the notch root and the controlled crack extension in the critical fracture splitting quality, to improve manufacturing quality. Thermal elastic-plastic incremental theory was applied to build the finite element analysis model of the stress field of pulsed laser grooving for fracture splitting based on the Rotary-Gauss body heat source. The corresponding numerical simulation of the stress field was conducted. The changes and distributions of the stress during pulsed laser grooving were examined, the influence rule of the primary technological parameters on the residual stress was analyzed, and the analysis results were validated by the corresponding cutting experiment. Results showed that the residual stress distribution was concentrated in the Heat-affected zone (HAZ) near the fracture splitting notch, which would cause micro-cracks in the HAZ. The stress state of the notch root in the fracture initiation direction was tensile stress, which was beneficial to the fracture initiation and the crack rapid extension in the subsequent fracture splitting process. However, the uneven distribution of the stress could lead to fracture splitting defects, and thus the residual stress should be lowered to a reasonable range. Decreasing the laser pulse power, increasing the processing speed, and lowering the pulse width can lower the residual stress. Along with the actual production, the reasonable main technological parameters were obtained.

  19. Evolution of Deformability and Transport Properties of Fractured Rocks Under the Action of Stress and Chemistry

    Elsworth, Derek; Taron, Josh; Faoro, Igor; Lee, Dae-Sung; Liu, Jishan; Niemeijer, Andre; Yasuhara, Hideaki


    Fluids in the shallow crust exert important controls on a wide spectrum of natural and engineered phenomena. The complex interaction of stress and particularly that of chemistry exhibit important feedbacks which influence the evolution of the mechanical and transport properties of rocks. These feedbacks in turn relate crucially to the subsurface recovery of hydrocarbons from the full spectrum of conventional through unconventional reservoirs, to the recovery of hydrothermal and non-hydrothermal geothermal resources, to the secure and enduring sequestration of energy by-products, and to the earthquake cycle, for example. We report on enigmatic interactions between stress and chemistry in mediating the evolution of permeability and strength in natural and engineered systems pushed far-from equilibrium. These include the roles of excess pore fluid pressures in driving transient changes in permeability and as well as the influence of changes in chemical potential in systems driven far-from-equilibrium. These effects are shown to result in significant changes in permeability that may vary on timescales of minutes to years as feedbacks switch from mechanically-driven to chemically-driven and as the length-scale of the prototype grows. These interactions are explored through coupled modeling including feedbacks in stress and chemistry as relevant to high-carbon through low-carbon energy systems. Examples are selected to illustrate the significance of these interactions in controlling the response of hydrocarbon and geothermal reservoirs, fracture treatments and radioactive waste disposal.

  20. Surgical treatment of bilateral femoral stress fractures related with long-term alendronate therapy.

    Kanatlı, Ulunay; Ataoğlu, M Baybars; Özer, Mustafa; Topçu, H Nevzat; Çetinkaya, Mehmet


    A 67-year-old female patient admitted to our outpatient clinic suffering from pain in both thighs for one year without any history of trauma. Patient was receiving alendronate therapy for five years. Physical examination revealed pain increasing with weight-bearing in both thighs with full range of hip and knee movements. Radiographs showed an area of thickened cortex of middle femoral diaphysis in both femurs, but no fracture. Bone scan showed a single area of increased uptake of radioisotope. These images were compatible with stress fractures of both femurs. Dual-energy X-ray absorptiometry revealed a T-score of -3.2 for the lumbar spine and -3.5 for the hip. Alendronate treatment was ceased. Calcium and vitamin D treatment were started. Patient was performed prophylactic surgical stabilization by titanium elastic nails in May 2009. On first day after the surgery, unsupported mobilization and weight-bearing activities were started. Upon persistence of pain on left thigh, plate fixation was performed for the nonunion in June 2012. Patient is now pain-free and able to walk with full weight-bearing without any complications.

  1. Stress Concentration and Fracture at Inter-variant Boundaries in an Al-Li Alloy

    Crooks, Roy; Tayon, Wes; Domack, Marcia; Wagner, John; Beaudoin, Armand


    Delamination fracture has limited the use of lightweight Al-Li alloys. Studies of secondary, delamination cracks in alloy 2090, L-T fracture toughness samples showed grain boundary failure between variants of the brass texture component. Although the adjacent texture variants, designated B(sub s1) and B(sub s2), behave similarly during rolling, their plastic responses to mechanical tests can be quite different. EBSD data from through-thickness scans were used to generate Taylor factor maps. When a combined boundary normal and shear tensor was used in the calculation, the delaminating grains showed the greatest Taylor Factor differences of any grain pairs. Kernel Average Misorientation (KAM) maps also showed damage accumulation on one side of the interface. Both of these are consistent with poor slip accommodation from a crystallographically softer grain to a harder one. Transmission electron microscopy was used to confirm the EBSD observations and to show the role of slip bands in the development of large, interfacial stress concentrations. A viewgraph presentation accompanies the provided abstract.

  2. Open-wedge high tibial osteotomy: incidence of lateral cortex fractures and influence of fixation device on osteotomy healing.

    Dexel, Julian; Fritzsche, Hagen; Beyer, Franziska; Harman, Melinda K; Lützner, Jörg


    Open-wedge high tibial osteotomy (HTO) is an established treatment for young and middle-aged patients with medial compartment knee osteoarthritis and varus malalignment. Although not intended, a lateral cortex fracture might occur during this procedure. Different fixation devices are available to repair such fractures. This study was performed to evaluate osteotomy healing after fixation with two different locking plates. Sixty-nine medial open-wedge HTO without bone grafting were followed until osteotomy healing. In patients with an intact lateral hinge, no problems were noted with either locking plate. A fracture of the lateral cortex occurred in 21 patients (30.4 %). In ten patients, the fracture was not recognized during surgery but was visible on the radiographs at the 6-week follow-up. Lateral cortex fracture resulted in non-union with the need for surgical treatment in three out of eight (37.5 %) patients using the newly introduced locking plate (Position HTO Maxi Plate), while this did not occur with a well-established locking plate (TomoFix) (0 out of 13, p = 0.023). With regard to other adverse events, no differences between both implants were observed. In cases of lateral cortex fracture, fixation with a smaller locking plate resulted in a relevant number of non-unions. Therefore, it is recommended that bone grafting, another fixation system, or an additional lateral fixation should be used in cases with lateral cortex fracture. III.

  3. Antidepressant use and 10-year incident fracture risk: the population-based Canadian Multicentre Osteoporosis Study (CaMoS)

    Bernatsky, S.; Abrahamowicz, M.; Papaioannou, A.; Bessette, L.; Adachi, J.; Goltzman, D.; Prior, J.; Kreiger, N.; Towheed, T.; Leslie, W. D.; Kaiser, S.; Ioannidis, G.; Pickard, L.; Fraser, L.-A.; Rahme, E.


    Summary We used data from a large, prospective Canadian cohort to assess the association between selective serotonin reuptake inhibitors (SSRIs) and serotonin and noradrenaline reuptake inhibitors (SNRIs) and fracture. We found an increased risk of fractures in individuals who used SSRI or SNRI, even after controlling for multiple risk factors. Introduction Previous studies have suggested an association between SSRIs and increasing risk of fragility fractures. However, the majority of these studies were not long-term analyses or were performed using administrative data and, thus, could not fully control for potential confounders. We sought to determine whether the use of SSRIs and SNRIs is associated with increased risk of fragility fracture, in adults aged 50+. Methods We used data from the Canadian Multicentre Osteoporosis Study (CaMos), a prospective randomly selected population-based community cohort; our analyses focused on subjects aged 50+. Time to event methodology was used to assess the association between SSRI/SNRI use, modeled time-dependently, and fragility fracture. Results Among 6,645 subjects, 192 (2.9 %) were using SSRIs or/and SNRIs at baseline. During the 10-year study period, 978 (14.7 %) participants experienced at least one fragility fracture. In our main analysis, SSRI/SNRI use was associated with increased risk of fragility fracture (hazard ratio (HR), 1.88; 95 % confidence intervals (CI), 1.48–2.39). After controlling for multiple risk factors, including Charlson score, previous falls, and bone mineral density hip and lumbar bone density, the adjusted HR for current SSRI/SNRI use remained elevated (HR, 1.68; 95 % CI, 1.32–2.14). Conclusions Our results lend additional support to an association between SSRI/SNRI use and fragility fractures. Given the high prevalence of antidepressants use, and the impact of fractures on health, our findings may have a significant clinical impact. PMID:24566587

  4. Extracorporeal shockwave therapy in the treatment of stress fracture of tibia. Report of a case

    Santiago Gómez García


    Full Text Available Pain in the lower limbs induced by exercise is common in military cadets due to long periods of jogging as part of his training and is related to overtraining. Stress fractures of tíbia are common among the disorders affecting them but most often are not diagnosed. The period of convalescence is prolonged sometimes leading to abandon their atividades. A case of an affected cadet to which treated by extracorporeal shockwave therapy showing reduced pain at rest and increased time trotting achieved without painful. Because of the importance that medical staff primarily Orthopaedic Surgeons and Sports Physicians and other health professionals involved in the care know about the existence of pathology as this new therapeutic alternative is that the case is presented.

  5. Exercise-induced rib stress fractures: potential risk factors related to thoracic muscle co-contraction and movement pattern

    Vinther-Knudsen, Archibald; Kanstrup, I-L; Christiansen, E


    The etiology of exercise-induced rib stress fractures (RSFs) in elite rowers is unclear. The purpose of the study was to investigate thoracic muscle activity, movement patterns and muscle strength in elite rowers. Electromyographic (EMG) and 2-D video analysis were performed during ergometer rowi...

  6. Investigating the Influence of Regional Stress on Fault and Fracture Permeability at Pahute Mesa, Nevada National Security Site

    Reeves, Donald M. [Desert Research Inst. (DRI), Reno, NV (United States); Smith, Kenneth D. [Univ. of Nevada, Reno, NV (United States); Parashar, Rishi [Desert Research Inst. (DRI), Reno, NV (United States); Collins, Cheryl [Desert Research Inst. (DRI), Las Vegas, NV (United States); Heintz, Kevin M. [Desert Research Inst. (DRI), Las Vegas, NV (United States)


    Regional stress may exert considerable control on the permeability and hydraulic function (i.e., barrier to and/or conduit for fluid flow) of faults and fractures at Pahute Mesa, Nevada National Security Site (NNSS). In-situ measurements of the stress field are sparse in this area, and short period earthquake focal mechanisms are used to delineate principal horizontal stress orientations. Stress field inversion solutions to earthquake focal mechanisms indicate that Pahute Mesa is located within a transtensional faulting regime, represented by oblique slip on steeply dipping normal fault structures, with maximum horizontal stress ranging from N29°E to N63°E and average of N42°E. Average horizontal stress directions are in general agreement with large diameter borehole breakouts from Pahute Mesa analyzed in this study and with stress measurements from other locations on the NNSS.

  7. Effect of timing of critical incident stress debriefing (CISD) on posttraumatic symptoms.

    Campfield, K M; Hills, A M


    Seventy-seven civilian employees who were victims of robbery were randomly assigned to either an immediate ( 48 hr) debriefing group, using the J. Mitchell (1983) CISD protocol. Scores on the Posttraumatic Stress Diagnostic Scale were obtained at 4 time intervals: debrief, 2 and 4 days post-debrief, and 2 weeks postrobbery. The number and severity of symptoms did not differ at debrief, but were lower for the immediate than for the delayed group at each subsequent time interval. The number and severity of symptoms declined across time intervals; however, although this reduction was pronounced for the immediate group it was minimal for the delayed group. The results supported use of immediate debriefing with this type of incident and victim.

  8. Numerical Evaluation and Optimization of Multiple Hydraulically Fractured Parameters Using a Flow-Stress-Damage Coupled Approach

    Yu Wang


    Full Text Available Multiple-factor analysis and optimization play a critical role in the the ability to maximizethe stimulated reservoir volume (SRV and the success of economic shale gas production. In this paper, taking the typical continental naturally fractured silty laminae shale in China as anexample, response surface methodology (RSM was employed to optimize multiple hydraulic fracturing parameters to maximize the stimulated area in combination with numerical modeling based on the coupled flow-stress-damage (FSD approach. This paper demonstrates hydraulic fracturing effectiveness by defining two indicesnamelythe stimulated reservoir area (SRA and stimulated silty laminae area (SLA. Seven uncertain parameters, such as laminae thickness, spacing, dip angle, cohesion, internal friction angle (IFA, in situ stress difference (SD, and an operational parameter-injection rate (IR with a reasonable range based on silty Laminae Shale, Southeastern Ordos Basin, are used to fit a response of SRA and SLA as the objective function, and finally identity the optimum design under the parameters based on simultaneously maximizingSRA and SLA. In addition, asensitivity analysis of the influential factors is conducted for SRA and SLA. The aim of the study is to improve the artificial ability to control the fracturing network by means of multi-parameteroptimization. This work promises to provide insights into the effective exploitation of unconventional shale gas reservoirs via optimization of the fracturing design for continental shale, Southeastern Ordos Basin, China.

  9. Simulation of three-dimensional tectonic stress fields and quantitative prediction of tectonic fracture within the Damintun Depression, Liaohe Basin, northeast China

    Guo, Peng; Yao, Leihua; Ren, Desheng


    Tectonic fractures are important factors that influence oil and natural gas migration and accumulation within "buried hill" reservoirs. To obtain a quantitative forecast of the development and distribution of reservoir fractures in the Damintun Depression, we analyzed the characteristics of regional structural evolution and paleotectonic stress field setting. A reasonable geological model of the research area was built based on an interpretation of the geological structure, a test for rock mechanics, and experiment on acoustic emission. Thereafter, a three-dimensional paleotectonic stress field during the Yanshan movement was simulated by the finite element method. Rock failure criterion and comprehensive evaluation coefficient of fractures were used to determine the quantitative development of fractures and predict zones that are prone to fracture development. Under an intense Yanshan movement, high stress strength is distributed in the south and northeast parts of the study area, where stress is extremely high. The fracture development zones are mainly controlled by the tectonic stress field and typically located in the same areas as those of high maximum principal and shear stresses. The predicted areas with developed fractures are consistent with the wells with high fracture linear density and in locations with high-producing oil and gas wells.

  10. Gas migration model based on overburden strata fracture evolution law in three dimensional mine-induced stress conditions

    Li, Xing; Yin, Guangzhi


    Based on the fracture features obtained from similarity simulation excavation experiment in 3D mine-induced stress condition, the gas migration model in gob area was set up, and numerical simulation using COMSOL Multiphysics software on gas migration law was studied. The research results show that: Gas pressure variety gradient and flow velocity are obviously influenced by fracture distribution shape. Gas concentration distribution presents the rounded rectangle shape in the lower strata, while in higher strata it tends to be a "O shape” morphology which is similar to the fracture form in strata above the gob. Besides, the pressure relief gas mainly accumulates in the working face fracture field, especially in the higher overlying strata. In the compaction field, gas concentration distribution form presents a “saddle” shape morphology in the vertical section, and gas concentration in boundary fracture zone is higher than in the compaction zone. It is remarkable that gas concentration in start-up fractured zone is also relatively high, and with the advance of working face, its gas enrichment degree decreases. The results of the research have an important guiding significance for coal and gas simultaneous extraction.

  11. The Relationship between Fractures and Tectonic Stress Field in the Extra Low-Permeability Sandstone Reservoir at the South of Western Sichuan Depression

    Zeng Lianbo; Qi Jiafu; Li Yuegang


    The formation and distribution of fractures are controlled by paleotectonic stress field, and their preservative status and effects on development are dominated by the modern stress field. Since Triassic, it has experienced four tectonic movements and developed four sets of tectonic fractures in the extra low-permeability sandstone reservoir at the south of western Sichuan depression. The strikes of fractures are in the S-N, NE-SW, E-W, and NW-SE directions respectively. At the end of Triassic, under the horizontal compression tectonic stress field, for which the maximum principal stress direction was NW-SE,the fractures were well developed near the S-N faults and at the end of NE-SW faults, because of their stress concentration. At the end of Cretaceous, in the horizontal compression stress fields of the NE-SW direction,the stress was obviously lower near the NE-SW faults, thus, fractures mainly developed near the S-N faults.At the end of Neogene-Early Pleistocene, under the horizontal compression tectonic stress fields of E-W direction, stress concentrated near the NE-SW faults and fractures developed at these places, especially at the end of the NE-SE faults, the cross positions of NE-SW, and S-N faults. Therefore, fractures developed mostly near S-N faults and NE-SW faults. At the cross positions of the above two sets of faults, the degree of development of the fractures was the highest. Under the modern stress field of the NW-SE direction, the NW-SE fractures were mainly the seepage ones with tensional state, the best connectivity, the widest aperture, the highest permeability, and the minimum opening pressure.

  12. Sports-related fractures in South East Scotland: an analysis of 990 fractures.

    Aitken, Stuart A; Watson, Bruce S; Wood, Alexander M; Court-Brown, Charles M


    To describe the characteristics of all sports related fractures in patients aged ≥ 15 years in South East Scotland in one year. Medical records of 990 consecutive patients aged ≥ 15 years who presented to the Orthopaedic Trauma Unit of the Royal Infirmary of Edinburgh with sports-related fractures between 1 July 2007 and 30 June 2008 were reviewed. Acute fractures of the upper limbs, lower limbs, pelvis, and cervical spine were included, but those of the skull, facial bones, and thorax were excluded, as were stress and chronic fractures. The incidence of sports-related fractures was 1.8/1000/year (82% involving men). The median age of patients was 25 (interquartile range, 19-35) years. Sports-related fractures accounted for 24.6% and 5.1% of all fractures in men and women, respectively. Men aged 15 to 19 years were 9 times more likely to have sports-related fractures than women of the same age. The sports-related fractures involved the upper limbs (52.4%), lower limbs (45.4%), and axial skeleton (2.2%). 12 of 49 sports (football, rugby, skiing, snowboarding, 3 cycling disciplines, horse riding, motocross, basketball, martial arts, and ice skating) accounted for 82.8% of all sports-related fractures. Upper limb fractures outnumbered lower limb fractures in all sports, except for horse riding and motocross that the proportions were similar. In South East Scotland, most sports related fractures involved the upper limbs.

  13. Coupling analysis of unsteady seepage and stress fields in discrete fractures network of rock mass in dam foundation


    The drag force of water flow through single fracture and the coupling characteristics of seepage and stress in single fracture surface are analyzed,and a three dimensional model of coupled unsteady seepage and stress fields is proposed.This model is used to the analysis of foundation rock mass of a high dam.If the coupling effects are considered,the changes of boundary heads have less influence on the inner head of rock mass,and the strong permeability of main fractures appears.If the coupling effects are not considered,the fractures distribution affects the inner head more greatly.When the upstream water head declines,the inner head of dam foundation slightly declines and the hydraulic gradient distribution becomes smoother.A bigger upstream water level declining velocity has a stronger lag effect,meanwhile the values of stress components change more greatly.Therefore the upstream water level declining velocity directly affects the stability of rock mass in dam foundation and we should take into account the above factors to make sure the safety of the dam during reservoir level fluctuation period.

  14. Cranberry juice concentrate does not significantly decrease the incidence of acquired bacteriuria in female hip fracture patients receiving urine catheter: a double-blind randomized trial

    Gunnarsson AK


    Full Text Available Anna-Karin Gunnarsson,1 Lena Gunningberg,2 Sune Larsson,1 Kenneth B Jonsson1 1Institution of Surgical Sciences, Uppsala University, Uppsala, Sweden; 2Institution of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden Background: Urinary tract infection (UTI is a common complication among patients with hip fractures. Receiving an indwelling urinary catheter is a risk factor for developing UTIs. Treatment of symptomatic UTIs with antibiotics is expensive and can result in the development of antimicrobial resistance. Cranberries are thought to prevent UTI. There is no previous research on this potential effect in patients with hip fracture who receive urinary catheters. Aim: The aim of this study is to investigate whether intake of cranberry juice concentrate preoperatively decreases the incidence of postoperative UTIs in hip fracture patients that received a urinary catheter. Design: This study employed a randomized, placebo-controlled double-blind trial. Method: Female patients, aged 60 years and older, with hip fracture (n=227 were randomized to receive cranberry or placebo capsules daily, from admission, until 5 days postoperatively. Urine cultures were obtained at admission, 5 and 14 days postoperatively. In addition, Euro Qual five Dimensions assessments were performed and patients were screened for UTI symptoms. Result: In the intention-to-treat analysis, there was no difference between the groups in the proportion of patients with hospital-acquired postoperative positive urine cultures at any time point. When limiting the analysis to patients that ingested at least 80% of the prescribed capsules, 13 of 33 (39% in the placebo group and 13 of 47 (28% in the cranberry group (P=0.270 had a positive urine culture at 5 days postoperatively. However, this difference was not statistically significant (P=0.270. Conclusion: Cranberry concentrate does not seem to effectively prevent UTIs in female patients with hip fracture and

  15. Experimental research on overlying strata movement and fracture evolution in pillarless stress-relief mining

    Junhua Xue; Hanpeng Wang; Wei Zhou; Bo Ren; Changrui Duan; Dongsheng Deng


    goaf was bounded by an expansion angle of broken strata in the lateral direction of the retained goaf-side roadway. The spatial and temporal evolution regularities of over-burden’s displacement field and stress field, dynamic development process and distribution of fracture field were analyzed. Based on the simulation results, it is recommended that several goaf drainage methods, i.e. gas drainage with buried pipes in goaf, surface goaf gas drainage, and cross-measure boreholes, should be implemented to ensure the safe mining of the panel 1111(1).


    Daniel R. Burns; Nafi Toksoz


    Using a 3-D finite difference method with a rotated-staggered-grid (RSG) scheme we generated synthetic seismograms for a reservoir model consisting of three horizontal layers with the middle layer containing parallel, equally spaced fractures. By separating and analyzing the backscattered signals in the FK domain, we can obtain an estimate of the fracture spacing. The fracture spacing is estimated by taking one-half of the reciprocal of the dominant wavenumber of the backscattered energy in data acquired normal to the fractures. FK analysis for fracture spacing estimation was successfully applied to these model results, with particular focus on PS converted waves. The method was then tested on data from the Emilio Field. The estimated fracture spacing from the dominant wavenumber values in time windows at and below the reservoir level is 25-40m. A second approach for fracture spacing estimation is based on the observation that interference of forward and backscattered energy from fractures introduces notches in the frequency spectra of the scattered wavefield for data acquired normal to the fracture strike. The frequency of these notches is related to the spacing of the fractures. This Spectral Notch Method was also applied to the Emilio data, with the resulting range of fracture spacing estimates being 25-50m throughout the field. The dominant spacing fracture spacing estimate is about 30-40 m, which is very similar to the estimates obtained from the FK method.

  17. Expedited patient-specific assessment of contact stress exposure in the ankle joint following definitive articular fracture reduction.

    Kern, Andrew M; Anderson, Donald D


    Acute injury severity, altered joint kinematics, and joint incongruity are three important mechanical factors linked to post-traumatic osteoarthritis (PTOA). Finite element analysis (FEA) was previously used to assess the influence of increased contact stress due to joint incongruity on PTOA development. While promising agreement with PTOA development was seen, the inherent complexities of contact FEA limited the numbers of subjects that could be analyzed. Discrete element analysis (DEA) is a simplified methodology for contact stress computation, which idealizes contact surfaces as a bed of independent linear springs. In this study, DEA was explored as an expedited alternative to FEA contact stress exposure computation. DEA was compared to FEA using results from a previously completed validation study of two cadaveric human ankles, as well as a previous study of post-operative contact stress exposure in 11 patients with tibial plafond fracture. DEA-computed maximum contact stresses were within 19% of those experimentally measured, with 90% of the contact area having computed contact stress values within 1MPa of those measured. In the 11 fractured ankles, maximum contact stress and contact area differences between DEA and FEA were 0.85 ± 0.64 MPa and 22.5 ± 11.5mm(2). As a predictive measure for PTOA development, both DEA and FEA had 100% concordance with presence of OA (KL grade ≥ 2) and >95% concordance with KL grade at 2 years. These results support DEA as a reasonable alternative to FEA for computing contact stress exposures following surgical reduction of a tibial plafond fracture.

  18. Baixa incidência de fraturas do quadril associadas à osteoporose, em Sobral-CE Low lncidence of hip fractures associated with osteoporosis in Sobral-CE

    Francisco Airton Castro da Rocha


    Full Text Available OBJETIVO: fraturas do quadril em pacientes acima de 60 anos representam séria morbidade ligada à osteoporose. Influências genéticas e ambientais foram relatadas como associadas à epidemiologia da osteoporose. Sobral, localizada no nordeste do Brasil (3º41'10" S/40º20'59"E, tem 138.565 mil habitantes que são predominantemente descendentes de brancos portugueses e índios brasileiros. MÉTODO: avaliamos a ocorrência de fraturas do quadril em Sobral entre julho de 1996 e junho de 2000. Os dados foram obtidos dos prontuários médicos da Santa Casa de Sobral, que é o hospital de referência local. Todos os registros de pacientes maiores de 20 anos com diagnóstico de fratura do fêmur ou do quadril foram revisados. RESULTADOS: identificamos no total 79 fraturas. Dez (12,6%, que ocorreram em menores de 50 anos, foram excluídas da análise. Sessenta e nove (87,3% ocorreram em maiores de 50 anos, compreendendo 19 (27,5% homens e 50 (72,4% mulheres, com uma incidência anual idadeajustada de 5,59/10.000/ano em homens e 12,4/10.000/ano em mulheres, respectivamente, para essa faixa etária. Dois pacientes, de 79 e 82 anos, morreram 9 e 6 dias após hospitalização, respectivamente. A média de tempo de hospitalização foi de 7,5 dias (variação de 4-19 dias. CONCLUSÕES: Houve tendência a acréscimo na incidência de fraturas de quadril em pessoas acima de 50 anos. A incidência de fraturas do quadril nessa população foi cerca de quatro vezes menor que a relatada em brancos caucasóides.OBJECTIVE: Hip fractures in patients older than 60 years old represent a serious morbidity linked to osteoporosis. Both genetic and environmental influences have been reported as important factors related to the epidemiology of osteoporosis. Sobral is located in the northeast of Brazil (3º41'10" S/40º20'59"E and has 138,565 inhabitants, which are mostly descendants from white Portuguese and native Brazilian. METHODS: We evaluated the occurrence of hip

  19. Stress inversion using borehole images and geometry evolution of the fractures in the Rittershoffen EGS project (Alsace, France).

    Azzola, Jérôme; Valley, Benoît; Schmittbuhl, Jean; Genter, Albert; Hehn, Régis


    In the Upper Rhine Graben, several deep geothermal projects based on the Enhanced Geothermal System (EGS) exploit local geothermal reservoirs. The principle underlying this technology consists of increasing the hydraulic performances of the reservoir by stimulating natural fractures using different methods, in order to extract hot water with commercially flow rates. In this domain, the knowledge of the in-situ stress state is of central importance to predict the response of the rock mass to stimulations. Here we characterized the stress tensor from Ultrasonic Borehole Imager (UBI) in the open hole section of the EGS doublet located in Rittershoffen, France (in the Upper Rhine Graben). Interestingly extensive logging programs were leaded at different key moments of the development of the injection well using hydraulic, thermal and chemical stimulation (Baujard et al., 2017)1. The time lapse UBI dataset consists of images of the injection well before, shortly and lastly after the stimulation. The geometry of the induced fractures in compression (breakouts) picked on the UBI images are used to determine the orientation of the in-situ stress tensor. The magnitude of the principal stresses is deduced from the drilling data. The magnitude of the maximum horizontal principal stress is evaluated using an inversion method with three failure criteria (Mohr-Coulomb, Mogi-Coulomb and modified Hoek-Brown criterion) and under the assumption of a vertical or a deviated well. Moreover, the characteristic of the dataset enables the analysis of the evolution of the borehole fracturing, as the deepening or widening of the induced fractures. The correlation of the UBI image allows firstly to determine the tool trajectory and to adapt the post and pre-stimulation images. It secondly leads to the estimation of a complete displacement field which characterizes the deformation induced by the stimulations. Even if the variable image quality deeply conditions the comparison, the considered

  20. Energy Release Rate in hydraulic fracture: can we neglect an impact of the hydraulically induced shear stress?

    Wrobel, Michal; Piccolroaz, Andrea


    A novel hydraulic fracture (HF) formulation is introduced which accounts for the hydraulically induced shear stress at the crack faces. It utilizes a general form of the elasticity operator alongside a revised fracture propagation condition based on the critical value of the energy release rate. It is shown that the revised formulation describes the underlying physics of HF in a more accurate way and is in agreement with the asymptotic behaviour of the linear elastic fracture mechanics. A number of numerical simulations by means of the universal HF algorithm previously developed in Wrobel & Mishuris (2015) are performed in order to: i) compare the modified HF formulation with its classic counterpart and ii) investigate the peculiarities of the former. Computational advantages of the revised HF model are demonstrated. Asymptotic estimations of the main solution elements are provided for the cases of small and large toughness. The modified formulation opens new ways to analyse the physical phenomenon of HF ...

  1. [Stress fracture of the scapular spine associated with rotator cuff dysfunction: Report of 3 cases and review of the literature].

    García-Coiradas, J; Lópiz, Y; Marco, F


    Scapular spine stress fractures have been scarcely reported in the literature. Their pathomechanics, clinical course and treatment are not well established. We review 3 cases in 2 patients that were associated with cuff dysfunction. On follow-up, none of these fractures progressed to healing. Two of them needed osteosynthesis and bone grafting, and the third one became a painless non-union. The authors propose the combination of 3 factors as a reason for this lesion: a functionally impaired cuff, a greater activation of the muscles with origin and insertion in the spine-acromion and a fragile bone. As we believe that these fractures are unstable, and non-union would be expected, their surgical management is recommended. Copyright © 2013 SECOT. Published by Elsevier Espana. All rights reserved.

  2. [The effect of stress ulcer prevention on the incidence of pneumonia in artificial respiration].

    Daschner, F; Reuschenbach, K; Pfisterer, J; Kappstein, I; Vogel, W; Krieg, N; Just, H


    The role of stress ulcer prophylaxis in increasing the risk of pneumonia in ventilator patients was analyzed prospectively in 142 artificially ventilated patients at a medical and surgical intensive care unit (104 males, 38 females, mean time of ventilation 7.9 days, mean age 46.5 years). The pH of gastric aspirate and bacterial counts in gastric fluid and tracheal secretions were investigated daily. Identical isolates from gastric aspirates and tracheal secretions were typed by agglutination, bacteriocin, or phage typing. An average of 2.1 bacterial species were isolated in 80.5% of all gastric aspirates. Bacterial counts increased with rising gastric aspirate pH, which was especially true for Gram-negative and less so for Gram-positive organisms; colony counts of Candida sp. decreased slightly. In 31.6% of patients identical bacterial species were first isolated from gastric aspirates and 1 to 2 days later from tracheal secretions. Of these microbes that were first isolated from gastric aspirate and later from tracheal secretions, 50.3% were Gram-negative, 37.5% Gram-positive, and only 4.2% Candida sp. One-half of all bacterial aspirations occurred between the 2nd and 7th day of ventilation; 80% occurred within 11 days of ventilation. Only 20% of all migrations of Gram-positive organisms from stomach to respiratory tract lead to pneumonia, as compared with 60% of Gram-negatives. At a gastric pH below 3.4 the incidence of ventilation pneumonia was 40.6%; above pH 5.0 the incidence was 69.2% (P less than or equal to 0.05). As pH increased, the organism causing pneumonia was significantly more often isolated first from the gastric aspirate and 1 to 2 days later from the tracheal secretion of the same patient.

  3. Iliotibial band release as an adjunct to the surgical management of patellar stress fracture in the athlete: a case report and review of the literature

    Keeley Anthony


    Full Text Available Abstract Stress fracture of the patella is rare. In this report, a case of patellar stress fracture occurring in an amateur athlete is presented, and an operative adjunct to the surgical management of this condition is proposed. A review of the English literature identified 21 previous cases of stress fracture of the patella, the majority in young athletes. None of these reports discussed treatment addressing the pathological process contributing to patellar stress fracture. The subject of this case report is a young male netballer who presented with a transverse stress fracture in the inferior third of his patella, on a background of patellofemoral overload. The patient underwent open reduction and internal fixation of his patella, combined with release of the iliotibial band. He returned to training after 6 weeks. The previous literature suggests that operative fixation is indicated for the treatment of displaced patellar stress fractures. Iliotibial band release, as a surgical adjunct to this treatment, may address the pathology of these fractures, and facilitate a return to sport at the highest level.

  4. Iliotibial band release as an adjunct to the surgical management of patellar stress fracture in the athlete: a case report and review of the literature.

    Keeley, Anthony; Bloomfield, Paul; Cairns, Peter; Molnar, Robert


    Stress fracture of the patella is rare. In this report, a case of patellar stress fracture occurring in an amateur athlete is presented, and an operative adjunct to the surgical management of this condition is proposed.A review of the English literature identified 21 previous cases of stress fracture of the patella, the majority in young athletes. None of these reports discussed treatment addressing the pathological process contributing to patellar stress fracture.The subject of this case report is a young male netballer who presented with a transverse stress fracture in the inferior third of his patella, on a background of patellofemoral overload. The patient underwent open reduction and internal fixation of his patella, combined with release of the iliotibial band. He returned to training after 6 weeks.The previous literature suggests that operative fixation is indicated for the treatment of displaced patellar stress fractures. Iliotibial band release, as a surgical adjunct to this treatment, may address the pathology of these fractures, and facilitate a return to sport at the highest level.

  5. Hormonal replacement therapy reduces forearm fracture incidence in recent postmenopausal women - results of the Danish Osteoporosis Prevention Study

    Mosekilde, Leif; Beck-Nielsen, H; Sørensen, O H


    OBJECTIVES: To study the fracture reducing potential of hormonal replacement therapy (HRT) in recent postmenopausal women in a primary preventive scenario. METHODS: Prospective controlled comprehensive cohort trial: 2016 healthy women aged 45-58 years, from three to 24 months past last menstrual ...

  6. Is crack branching under shear loading caused by shear fracture? ——A critical review on maximum circumferential stress theory



    When a crack is subjected to shear force, crack branching usually occurs. Theoretical study shows that the crack branching under shear loading is caused by tensile stress, but not caused by shear fracture. The co-plane shear fracture could be obtained if compressive stress with given direction is applied to the specimen, subsequently, calculated shear fracture toughness, KⅡ C, is larger than KⅠ C. A prerequisite of possible occurrence of mode Ⅱ fracture was proposed. The study of shear fracture shows that the maximum circumferential stress theory considered its criterion as a parametric equation of a curve in KⅠ, KⅡ plane is incorrect; the predicted ratio KⅡ C/KⅠ C=0.866 is incorrect too.

  7. The Family Debriefing Model: An Adapted Critical Incident Stress Debriefing for Parents and Older Sibling Suicide Survivors.

    Juhnke, Gerald A.; Shoffner, Marie F.


    Describes a model developed for use with parents and older sibling survivors who have experienced a family member's suicide. The model combines solution-focused interventions with an adapted Critical Incident Stress Debriefing model. The model encourages survivors to participate in an experiential process that promotes discussion and…

  8. ASGW Best Practice Guidelines as a Research Tool: A Comprehensive Examination of the Critical Incident Stress Debriefing

    Pender, Debra Ann; Prichard, Karen K.


    Crisis intervention group work is routinely provided to those that have been exposed to potentially traumatizing events. The Critical Incident Stress Debriefing (CISD) has been identified as a standard format for conducting crisis groups, yet the intervention is highly debated in the literature. This article reviews the status of that debate,…

  9. Characterization of In-Situ Stress and Permeability in Fractured Reservoirs

    Daniel R. Burns; M. Nafi Toksoz


    Fracture orientation and spacing are important parameters in reservoir development. This project resulted in the development and testing of a new method for estimating fracture orientation and two new methods for estimating fracture spacing from seismic data. The methods developed were successfully applied to field data from fractured carbonate reservoirs. Specific results include: the development a new method for estimating fracture orientation from scattered energy in seismic data; the development of two new methods for estimating fracture spacing from scattered energy in seismic data; the successful testing of these methods on numerical model data and field data from two fractured carbonate reservoirs; and the validation of fracture orientation results with borehole data from the two fields. Researchers developed a new method for determining the reflection and scattering characteristics of seismic energy from subsurface fractured formations. The method is based upon observations made from 3D finite difference modeling of the reflected and scattered seismic energy over discrete systems of vertical fractures. Regularly spaced, discrete vertical fractures impart a ringing coda type signature to seismic energy that is transmitted through or reflected off of them. This signature varies in amplitude and coherence as a function of several parameters including: (1) the difference in angle between the orientation of the fractures and the acquisition direction, (2) the fracture spacing, (3) the wavelength of the illuminating seismic energy, and (4) the compliance, or stiffness, of the fractures. This coda energy is the most coherent when the acquisition direction is parallel to the strike of the fractures. It has the largest amplitude when the seismic wavelengths are tuned to the fracture spacing, and when the fractures have low stiffness. The method uses surface seismic reflection traces to derive a transfer function that quantifies the change in the apparent source

  10. Serum 25-hydroxyvitamin D level and incident type 2 diabetes in older men, the Osteoporotic Fractures in Men (MrOS) study.

    Napoli, Nicola; Schafer, Anne L; Lui, Li-Yung; Cauley, Jane A; Strotmeyer, Elsa S; Le Blanc, Erin S; Hoffman, Andrew R; Lee, Christine G; Black, Dennis M; Schwartz, Ann V


    The association between vitamin D status and diabetes risk is inconsistent among observational studies, and most of the available studies have been with women. In the present study we investigated the association between serum 25-hydroxyvitamin D (25(OH)D) levels and incident type 2 diabetes (T2D) in older men (≥65years old) who participated in the multisite Osteoporotic Fractures in Men (MrOS) study enrolled from March 2000 to April 2002. Baseline 25(OH)D levels were available in 1939 subjects without prevalent T2D. Clinical information, body mass index (BMI) and other factors related to T2D were assessed at the baseline visit. Incident diabetes, defined by self-report and medication use, was determined over an average follow-up of 6.4years. At baseline, participants were, on average, 73.3 (±5.7) years old, had a mean BMI in the overweight range (27.2kg/m(2)±3.6) and had total serum 25(OH)D of 26.1ng/ml (±8.3). Incident diabetes was diagnosed in 139 subjects. Cox regression analysis showed a trend toward a protective effect of higher 25(OH)D levels with a lower risk of T2D (HR 0.87, 95% CI: 0.73-1.04 per 1 SD increase of 25(OH)D). After adjusted for BMI and other potential confounders, the relationship between 25(OH)D levels and incident diabetes was further attenuated (HR 1.03, 95% CI 0.85-1.25). No significant difference in the incidence of diabetes emerged after analyzing study subjects according to baseline 25(OH)D quartiles. In conclusion, 25(OH)D levels were not associated with incident T2D in older men.

  11. Diagnostic accuracy of 3-T magnetic resonance imaging with 3D T1 VIBE versus computer tomography in pars stress fracture of the lumbar spine

    Ang, E.C.; Robertson, A.F.; Malara, F.A.; O' Shea, T.; Roebert, J.K.; Rotstein, A.H. [Victoria House Medical Imaging, Prahran, Victoria (Australia); Schneider, M.E. [Monash University, Monash Biomedicine Discovery Institute, Department of Medical Imaging and Radiation Sciences, Faculty of Medicine, Nursing and Health Sciences, Clayton, Victoria (Australia)


    To compare the diagnostic accuracy of 3-T magnetic resonance imaging (MRI) with thin-slice 3D T1 VIBE sequence to 128-slice computer tomography (CT) in pars stress fractures of the lumbar spine. 3-T MRI and CT of 24 patients involving 70 pars interarticularis were retrospectively reviewed by four blinded radiologists. The fracture morphology (complete, incomplete, or normal) was assessed on MRI and CT at different time points. Pars interarticularis bone marrow edema (present or absent) was also evaluated on MRI. In total, 14 complete fractures, 31 incomplete fractures and 25 normal pars were detected by CT. Bone marrow edema was seen in seven of the complete and 25 of the incomplete fractures. The overall sensitivity, specificity and accuracy of MRI in detecting fractures (complete and incomplete) were 97.7, 92.3, and 95.7 %, respectively. MRI was 100 % accurate in detecting complete fractures. For incomplete fractures, the sensitivity, specificity, and accuracy of MRI were 96.7, 92.0, and 94.6 %, respectively. 3-T MRI with thin-slice 3D T1 VIBE is 100 % accurate in diagnosing complete pars fractures and has excellent diagnostic ability in the detection and characterization of incomplete pars stress fractures compared to CT. MRI has the added advantages of detecting bone marrow edema and does not employ ionizing radiation. (orig.)

  12. Sports fractures.

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


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

  13. Stress fractures of the ankle malleoli diagnosed by ultrasound: a report of 6 cases

    Bianchi, Stefano [CIM SA, Cabinet Imagerie Medicale, Geneve (Switzerland); Luong, Dien Hung [CIM SA, Cabinet Imagerie Medicale, Geneve (Switzerland); University of Montreal, Department of Physical Medicine and Rehabilitation, Montreal (Canada)


    To present the ultrasound appearance of stress fractures (SF) of the ankle malleoli. We present a retrospective review of 6 patients (4 women and 2 men, with an age range of 24-52 years, mean age of 39 years) in which ultrasound diagnosed, together with the clinical findings, an SF of the ankle malleoli. For all of these patients ultrasound was the first imaging technique applied because of a clinical suspicion of soft tissue injuries following excessive exertion. Patients were subsequently examined using standard radiographs and/or MRI. At ultrasound patients showed thickening of the periosteum in all patients, calcified bone callus was evident in 3 out of 6 patients. Cortical irregularities and subcutaneous oedema were found in all but one patient. Colour Doppler showed local hypervascular changes in all patients. Local compression with the transducers during real-time scanning increased pain in all cases. Ultrasound, together with the clinical findings, can diagnose an SF of the ankle malleoli. We suggest that sonologists should include malleolar SF in their differential diagnosis, particularly in the case of perimalleolar pain from over-solicitation. They must also include, as part of every ultrasound examination of the ankle, the evaluation of both malleoli and should be aware of the ultrasound appearance of malleolar SF. If the diagnosis remains uncertain, an MRI should be prescribed. (orig.)

  14. In-situ stress and fracture characterization for planning of a hydraulic stimulation in the Desert Peak Geothermal Field, NV

    Hickman, S.; Davatzes, N. C.


    A suite of geophysical logs and a hydraulic fracturing stress measurement were conducted in well 27-15 in the Desert Peak Geothermal Field, Nevada, to constrain the state of stress and the geometry and relative permeability of natural fractures in preparation for development of an Enhanced Geothermal System (EGS) through hydraulic stimulation. Advanced Logic Technologies Borehole Televiewer (BHTV) and Schlumberger Formation MicroScanner (FMS) image logs reveal extensive drilling-induced tensile fractures, showing that the current minimum horizontal principal stress, Shmin, in the vicinity of well 27-15 is oriented 114 ± 17°. This orientation is consistent with down-dip extensional slip on a set of ESE and WNW dipping normal faults mapped at the surface. Similarly, all formations imaged in the BHTV and FMS logs include significant sub-populations of fractures that are well oriented for normal faulting given this direction of Shmin. Although the bulk permeability of the well is quite low, temperature and spinner flowmeter surveys reveal several minor flowing fractures. Some of these relatively permeable fractures are well oriented for normal faulting, in addition to fluid flow that is preferentially developed at low-angle formation boundaries. A hydraulic fracturing stress measurement conducted at the top of the intended stimulation interval (931 m) indicates that the magnitude of Shmin is 13.8 MPa, which is 0.609 of the calculated vertical (overburden) stress at this depth. Given the current water table depth (122 m below ground level), this Shmin magnitude is somewhat higher than expected for frictional failure on optimally oriented normal faults given typical laboratory measurements of sliding friction (Byerlee’s Law). Coulomb failure calculations assuming cohesionless pre-existing fractures with coefficients of friction of 0.6 or higher (consistent with Byerlee’s Law and with tests on representative core samples from nearby wells) indicate that shear

  15. On the predictive capabilities of the shear modified Gurson and the modified Mohr-Coulomb fracture models over a wide range of stress triaxialities and Lode angles

    Dunand, Matthieu; Mohr, Dirk


    The predictive capabilities of the shear-modified Gurson model [Nielsen and Tvergaard, Eng. Fract. Mech. 77, 2010] and the Modified Mohr-Coulomb (MMC) fracture model [Bai and Wierzbicki, Int. J. Fract. 161, 2010] are evaluated. Both phenomenological fracture models are physics-inspired and take the effect of the first and third stress tensor invariants into account in predicting the onset of ductile fracture. The MMC model is based on the assumption that the initiation of fracture is determined by a critical stress state, while the shear-modified Gurson model assumes void growth as the governing mechanism. Fracture experiments on TRIP-assisted steel sheets covering a wide range of stress states (from shear to equibiaxial tension) are used to calibrate and validate these models. The model accuracy is quantified based on the predictions of the displacement to fracture for experiments which have not been used for calibration. It is found that the MMC model predictions agree well with all experiments (less than 4% error), while less accurate predictions are observed for the shear-modified Gurson model. A comparison of plots of the strain to fracture as a function of the stress triaxiality and the normalized third invariant reveals significant differences between the two models except within the vicinity of stress states that have been used for calibration.

  16. Incidence of auditory ossicle luxation and petrous bone fractures detected in post-mortem multislice computed tomography (MSCT).

    Hollinger, A; Christe, A; Thali, M J; Kneubuehl, B P; Oesterhelweg, L; Ross, S; Spendlove, D; Bolliger, S A


    As the auditory ossicles are difficult to display without harming them in conventional autopsies, lesions of these minute bones and the ossicular chain are regularly missed. In this study, the method of choice in clinical medicine for the examination of such lesions, namely multislice computed tomography, was applied to 100 corpses. The hereby obtained results regarding ossicle luxation and petrous bone fracture indicated that the lesions were not dependant on the amount, but rather on the type of energy inflicted to the head.

  17. 应用J积分断裂准则评价应力吸收层抗裂性能%Evaluation Fracture Resistance of Stress Absorbing Layer Using J-Integral Fracture Criterion

    刘宇; 张肖宁; 薛忠军


    Fracture resistance of three kinds of stress absorbing layers were evaluated based on the J-integral theory of elasticity-plasticity fracture mechanics by semi-circular bending test, and the critical fracture resistance were compared with relative study. It is shown that gap gradation stress absorbing layer has the better fracture resistance. The results indicate that the critical fracture resistance-jCis appropriate to appraise the fracture resistance of stress absorbing layer, and the gap gradation asphalt mixtures with skeleton structure and full asphalt binders can increase its fracture resistance.%应用弹塑性断裂力学J积分理论,采用半圆弯曲试验评价了3种级配应力吸收层的抗裂性能,发现采用断级配设计的应力吸收层具有良好的抗裂性能,结果表明断裂韧度JC可以用来评价应力吸收层的抗裂性能,由丰富沥青胶浆填充断级配骨架结构的级配设计,可以提高沥青混合料的抗裂能力.


    Daniel R. Burns; M. Nafi Toksoz


    A 3-D elastic wave propagation finite difference model, including effects of attenuation, has been implemented and compared with other existing modeling codes for validation. Models of seismic scattering from discrete large-scale fractures as well as equivalent anisotropic medium representations of small-scale fractures have been generated and used to develop data analysis methods for applications to seismic field data. An inversion scheme has been developed to estimate fracture orientation and fracture density from amplitude variations with offset and azimuth (AVOA). The method has been tested on synthetic data and field data from an offshore fractured carbonate reservoir with promising results. Spectral characteristics of the numerical model data of the seismic wavefield scattered from aligned fractures with different spacing between fracture zones have been analyzed. Results indicate that the spacing of these large, open fracture zones can be estimated from the wavenumber spectra of the scattered wave amplitude as a function of offset in pre-stack data. Two approaches for converting seismically derived fracture parameters into fluid-flow parameters for use in reservoir simulators have been identified. The first is the numerical modeling of Stoke's flow in fracture networks, and the second uses a statistical model of a fracture distribution that allows for the calculation of the elastic properties and permeability tensor of the resulting equivalent medium. These approaches will be compared in the coming year. Multiple meetings have been held with our industry partner, Shell Oil, to identify a field test site for the project. We are focusing our efforts on a fractured carbonate field. The field application test site selection and data transfer will be completed in the coming year.

  19. Effect of Crack Tip Stress Concentration Factor on Fracture Resistance in Vacuum Environment


    aluminum alloys and a steel in vacuum environment. The materials investigated were peakaged 7075 -T651, overaged 7075 -T7351, 5083-H131, fully sensitized Al...about twice higher than those of the aluminum alloys; (4) the peakaged 7075 -T651 and overaged 7075 -T7351 have comparable fracture resistance; (5...the fracture resistance of 2024-T351 alloy is higher than 7075 alloys; (6) the fracture resistances of as-received 5083-H131 (5083R) and sensitized

  20. [Acetabular fractures].

    Gänsslen, A; Oestern, H J


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

  1. Low incident angle and classical x-ray diffraction analysis of residual stresses in diamond coated Si3N4

    Soares, M. R.; Belmonte, M.; Silva, R. F.


    The overall residual stresses and the stress distribution on chemical vapor deposition diamond coated silicon nitride (Si3N4) are investigated by x-ray diffraction using the classical sin2 ψ method and the low incident beam angle diffraction technique, respectively. The deposition time and the substrate surface roughness evidence a clear effect on the film texture and residual stress generation on the diamond coatings. For the roughest substrate, 15 μm polished diamond, as the deposition time increases from 2 to 6 h, a remarkable improvement of the (220) texture and compressive stress relaxation occur from -0.75 to -0.14 GPa. A change to less compressive and even to slight tensile stress takes place for the smoothest substrate, colloidal finished silica, giving stress values of -0.40 and 0.21 GPa for 2 and 6 h of deposition time, respectively. The stress profile along the film thickness for the 6 h grown diamond film on the 15 μm polished substrate exhibits a linear decrease, in absolute values, from a compressive residual stress of -3.7 GPa, in the upper layer of the film, to almost zero stress at the film/substrate interface.

  2. Observed Rates of Lower Extremity Stress Fractures After Implementation of the Army Physical Readiness Training Program at JBSA Fort Sam Houston.

    Chalupa, Robyn L; Aberle, Curtis; Johnson, Anthony E


    Millions of dollars are lost each year to the US military in medical discharges from injuries sustained in the initial training of recruits. Most medical discharges in recruits are related to musculoskeletal overuse injuries, including stress fractures. Any strategies that can reduce injury rates are also likely to reduce rates of medical discharge. This study evaluated the Army Physical Readiness Training (PRT) program which was established to provide a method of physical fitness training that would reduce the number of preventable injuries. We conducted a retrospective study to evaluate the number of lower extremity stress fractures that were diagnosed in the 6 months prior to and 6 months following the implementation of the PRT program. Electronic medical records were queried for specific diagnoses of stress fractures to the pelvis, femoral neck, femoral shaft, tibia, fibula, tarsals and metatarsals. The observed number of diagnoses in each time period were compared using the χ² method. Decrease was shown not only in the overall occurrence of stress fractures, but specifically in the occurrence of stress fractures of the femoral neck, femoral shaft, and tarsals. Our study was able to show a correlation between the PRT program and a decrease in the observed occurrence of lower extremity stress fractures.

  3. Incidence and pattern of traumatic spinal fractures and associated spinal cord injury resulting from motor vehicle collisions in China over 11 years

    Wang, Hongwei; Liu, Xinwei; Zhao, Yiwen; Ou, Lan; Zhou, Yue; Li, Changqing; Liu, Jun; Chen, Yu; Yu, Hailong; Wang, Qi; Han, Jianda; Xiang, Liangbi


    Abstract To investigate the incidence and pattern of traumatic spinal fractures (TSFs) and associated spinal cord injury (SCI) resulting from motor vehicle collisions (MVCs). This was a cross-sectional study. We retrospectively reviewed 698 patients with TSFs resulting from MVCs admitted to our university-affiliated hospitals from 2001 to 2011. The incidence and pattern were summarized with respect to different age groups, fracture levels, and the role of patients. There were 464 males (66.5%) and 234 females (33.5%) aged 40.5 ± 13.8 years old. The most common roles of patients in MVCs were car drivers (189, 27.1%), pedestrians hurt by a car (155, 22.2%), and car passengers (145, 20.8%). The most common fracture levels were L1 (n = 198, 19.2%) and T12 (n = 116, 11.3%), followed by C2 (n = 86, 8.3%). A total of 298 (42.7%) patients suffered a spinal cord injury. The frequencies of SCIs decreased from 53.1% to 24.6% with increasing age. The patients in the 20 to 39 age group (45.3% of all patients) had the largest sex ratio (2.4) and highest frequency of complete SCIs (19.3%) and complications (3.2%). Motorcycle drivers had the youngest mean age (35.7 ± 10.2), largest sex ratio (10.4), and highest frequency of SCIs (56.0%) and complications (4.4%). Motorcycle passengers had the highest frequency of complete SCI (22.7%) and ASOIs (45.5%) and the largest mean injury severity scoring (ISS) (18.9 ± 9.6). The most common fracture levels of motorcycle drivers were C3–C7, while that of others were T11–L2. The most common role of patients who sustained TSFs were car drivers who were 20 to 39 years old. Motorcycle drivers had the highest frequency of SCIs and complications. Motorcycle passengers had the highest frequency of complete SCIs and ASOIs and the largest ISS. Therefore, we should pay more attention to MVC patients, especially car drivers and motorcycle drivers and passengers. PMID:27787384

  4. Is vaccenic acid (18:1t n-7) associated with an increased incidence of hip fracture? An explanation for the calcium paradox.

    Hamazaki, Kei; Suzuki, Nobuo; Kitamura, Kei-Ichiro; Hattori, Atsuhiko; Nagasawa, Tetsuro; Itomura, Miho; Hamazaki, Tomohito


    High calcium intake may increase hip fracture (HF) incidence. This phenomenon, known as the calcium paradox, might be explained by vaccenic acid (18:1t n-7, VA), the highly specific trans fatty acid (TFA) present in dairy products. First, we ecologically investigated the relationship between 18:1 TFA intake and HF incidence using data from 12 to 13 European countries collected before 2000; then we measured the effects of VA and elaidic acid (18:1t n-9, EA) on osteoblasts from goldfish scales (tissues very similar to mammalian bone), with alkaline phosphatase as a marker; and finally we measured the effect of VA on mRNA expression in the scales for the major bone proteins type I collagen and osteocalcin. HF incidence was significantly correlated with 18:1 TFA intake in men (r=0.57) and women (r=0.65). Incubation with 1μmol/L VA and EA for 48h significantly decreased alkaline phosphatase activity by 25% and 21%, respectively. Incubation of scales with 10μmol/L VA for 48h significantly decreased mRNA expression for type I collagen and osteocalcin (by about 50%). In conclusion, VA may be causatively related to HF and could explain the calcium paradox. It may be prudent to reduce 18:1 TFA intake, irrespective of trans positions, to prevent HF. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Experimental-numerical evaluation of a new butterfly specimen for fracture characterisation of AHSS in a wide range of stress states

    Peshekhodov, I.; Jiang, S.; Vucetic, M.; Bouguecha, A.; Berhens, B.-A.


    Results of an experimental-numerical evaluation of a new butterfly specimen for fracture characterisation of AHHS sheets in a wide range of stress states are presented. The test on the new butterfly specimen is performed in a uniaxial tensile machine and provides sufficient data for calibration of common fracture models. In the first part, results of a numerical specimen evaluation are presented, which was performed with a material model of a dual-phase steel DP600 taken from literature with plastic flow and fracture descriptions. In the second part, results of an experimental-numerical specimen evaluation are shown, which was conducted on another dual-phase steel DP600, which was available with a description of plastic flow only and whose fracture behaviour was characterised in the frame of this work. The overall performance of the new butterfly specimen at different load cases with regard to characterisation of the fracture behaviour of AHSS was investigated. The dependency of the fracture strain on the stress triaxiality and Lode angle as well as space resolution is quantified. A parametrised CrachFEM ductile shear fracture model and modified Mohr-Coloumb ductile shear fracture model are presented as a result of this quantification. The test procedure and results analysis are believed to contribute to current discussions on requirements to AHSS fracture characterisation.

  6. Seismic monitoring of hydraulic fracturing: techniques for determining fluid flow paths and state of stress away from a wellbore

    Fehler, M.; House, L.; Kaieda, H.


    Hydraulic fracturing has gained in popularity in recent years as a way to determine the orientations and magnitudes of tectonic stresses. By augmenting conventional hydraulic fracturing measurements with detection and mapping of the microearthquakes induced by fracturing, we can supplement and idependently confirm information obtained from conventional analysis. Important information obtained from seismic monitoring includes: the state of stress of the rock, orientation and spacing of the major joint sets, and measurements of rock elastic parameters at locations distant from the wellbore. While conventional well logging operations can provide information about several of these parameters, the zone of interrogation is usually limited to the immediate proximity of the borehole. The seismic waveforms of the microearthquakes contain a wealth of information about the rock in regions that are otherwise inaccessible for study. By reliably locating the hypocenters of many microearthquakes, we have inferred the joint patterns in the rock. We observed that microearthquake locations do not define a simple, thin, planar distribution, that the fault plane solutions are consistent with shear slippage, and that spectral analysis indicates that the source dimensions and slip along the faults are small. Hence we believe that the microearthquakes result from slip along preexisting joints, and not from tensile extension at the tip of the fracture. Orientations of the principal stresses can be estimated by using fault plane solutions of the larger microearthquakes. By using a joint earthquake location scheme, and/or calibrations with downhole detonators, rock velocities and heterogeneities thereof can be investigated in rock volumes that are far enough from the borehole to be representative of intrincis rock properties.

  7. A Study of Structural Stress Technique for Fracture Prediction of an Auto-Mobile Clutch Snap-Ring

    Kim, Ju Hee [Korea Military Academy, Seoul (Korea, Republic of); Myeong, Man Sik [Samsung Display, Suwon (Korea, Republic of); Oh, Chang Sik [KINS, Daejeon (Korea, Republic of); Kim, Yun Jae [Korea Univ., Sejong (Korea, Republic of)


    The endurance reliability assessment of a highly complex mechanism is generally predicted by the fatigue life based on simple stress analysis. This study discusses various fatigue life assessment techniques for an automobile clutch snap ring. Finite element analyses were conducted to determine the structural stress on the snap ring. Structural stress that is insensitive in regards to the mesh size and type definition is presented in this study. The structural stress definition is consistent with elementary structural mechanics theory and provides an effective measure of a stress state that pertains to fatigue behavior of welded joints in the form of both membrane and bending components. Numerical procedures for both solid models and shell or plate element models are presented to demonstrate the mesh-size insensitivity when extracting the structural stress parameters. Conventional finite element models can be used with the structural stress calculations as a post-processing procedure. The two major implications from this research were: (a) structural stresses pertaining to fatigue behavior can be consistently calculated in a mesh-insensitive manner regardless of the types of finite element models; and (b) by comparing with the clutch snap-ring fatigue test data, we should predict the fatigue fractures of an automobile clutch snap ring using this method.

  8. An integrated workflow for stress and flow modelling using outcrop-derived discrete fracture networks

    Bisdom, Kevin; Nick, Hamid; Bertotti, Giovanni


    stresssensitive fracture permeability and matrix flow to determine the full permeability tensor. The applicability of this workflow is illustrated using an outcropping carbonate pavement in the Potiguar basin in Brazil, from which 1082 fractures are digitised. The permeability tensor for a range of matrix...

  9. Associations of Sarcopenic Obesity and Dynapenic Obesity with Bone Mineral Density and Incident Fractures Over 5-10 Years in Community-Dwelling Older Adults.

    Scott, David; Chandrasekara, Sahan D; Laslett, Laura L; Cicuttini, Flavia; Ebeling, Peter R; Jones, Graeme


    The purpose of this study is to determine whether low muscle mass (sarcopenia) or strength (dynapenia), in the presence of obesity, are associated with increased risk for osteoporosis and non-vertebral fracture over 5-10 years in community-dwelling older adults. N = 1089 volunteers (mean ± SD age 62 ± 7 years; 51 % female) participated at baseline and 761 attended follow-up clinics (mean 5.1 ± 0.5 years later). Total body, total hip and spine BMD, and appendicular lean and total fat mass were assessed by DXA. Sarcopenic obesity and dynapenic obesity were defined as the lowest sex-specific tertiles for appendicular lean mass or lower-limb strength, respectively, and the highest sex-specific tertile for total fat mass. Fractures were self-reported on three occasions over 10.7 ± 0.7 years in 563 participants. Obese alone participants had significantly higher BMD at all sites compared with non-sarcopenic non-obese. Sarcopenic obese and dynapenic obese men had lower spine and total body BMD, respectively, and sarcopenic obese women had lower total hip BMD, compared with obese alone (all P obese men had higher non-vertebral fracture rates compared to non-sarcopenic non-obese (incidence rate ratio: 3.0; 95 % CI 1.7-5.5), and obese alone (3.6; 1.7-7.4). Sarcopenic obese women had higher fracture rates compared with obese alone (2.8; 1.4-5.6), but this was non-significant after adjustment for total hip BMD. Sarcopenic and dynapenic obese older adults may have increased risk of osteoporosis and non-vertebral fracture relative to obese alone counterparts. Sarcopenic and dynapenic obese individuals potentially represent a subset of the obese older adult population who require closer monitoring of bone health during ageing.

  10. Estimation of return-to-sports-time for athletes with stress fracture – an approach combining risk level of fracture site with severity based on imaging

    Dobrindt Oliver


    Full Text Available Abstract Background The aim was to compare the return-to-sports-time (RTST following stress fractures on the basis of site and severity of injury. This retrospective study was set up at a single institution. Diagnosis was confirmed by an interdisciplinary adjudication panel and images were rated in a blinded-read setting. Methods 52 athletes (female, n = 30; male, n = 22; mean age, 22.8 years with stress fracture (SFX who had undergone at least one examination, either MRI or bone scintigraphy, were included. Magnetic resonance images (MRI and/or bone scintigraphy (BS of SFX were classified as either low- or high-grade SFX, according to existing grading systems. For MRI, high-grade SFX was defined as visibility of a fracture line or bone marrow edema in T1-, T2-weighted and short tau inversion recovery (STIR sequences, with low-grade SFX showing no fracture line and bone marrow edema only in STIR and/or T2-weighted sequences. In BS images, a mild and poorly defined focal tracer uptake represented a low-grade lesion, whereas an intense and sharply marginated uptake marked a high-grade SFX. In addition, all injuries were categorized by location as high- or low-risk stress fractures. RTST was obtained from the clinical records. All patients were treated according to a non-weight-bearing treatment plan and comprehensive follow-up data was complete until full recovery. Two-sided Wilcoxon’s rank sum test was used for group comparisons. Results High-risk SFX had a mean RTST of 132 days (d [IQR 64d – 132d] compared to 119d [IQR 50d – 110d] for low-risk sites (p = 0.19. RTST was significantly longer (p = 0.01 in high-grade lesions [mean, 143d; IQR 66d – 134d] than in low-grade [mean, 95d; IQR 42d – 94d]. Analysis of high-risk SFX showed no difference in RTST (p = 0.45 between high- and low-grade [mean, 131d; IQR 72d – 123d vs. mean, 135d; IQR 63d – 132d]. In contrast, the difference was significant for low-risk SFX

  11. Permeability reduction by pyrobitumen, mineralization, and stress along large natural fractures in sandstones at 18,300 ft. depth: Destruction of a reservoir

    Lorenz, J.C. [SPE, Richardson, TX (United States)]|[Sandia National Lab., Albuquerque, NM (United States); Billingsley, R.L.; Evans, L.W.


    Production of gas from the Frontier Formation at 18,300 R depth in the Frewen No. 4 Deep well, eastern Green River basin (Wyoming), was uneconomic despite the presence of numerous open natural fractures. Initial production tested at 500 MCFD, but dropped from 360 MCFD to 140 MCFD during a 10-day production test, and the well was abandoned. Examination of the fractures in the core suggests several probable reasons for this poor production. One factor is the presence of a hydrocarbon residue (carbon) which filled much of the porosity left in the smaller fractures after mineralization. An equally important factor is probably the reorientation of the in situ horizontal compressive stress to a trend normal to the main fractures, and which now acts to close fracture apertures rapidly during reservoir drawdown. This data set has unpleasant implications for the search for similar, deep fractured reservoirs.

  12. Rib stress fractures among rowers: a systematic review on return to sports, risk factors and prevention.

    D'Ailly, Philip N; Sluiter, Judith K; Kuijer, Paul P


    Rib stress fractures (RSFs) are injuries frequently sustained by elite rowers with an injury rate of 8-16% over the course of a rowing career, resulting in negative effects on training and performance. For clinical management, the aim of this review was to describe time to return to sports, summarize potentially preventive measures and appraise the evidence on risk factors. A search strategy was performed in PubMed, SportDiscus, Web of Science and Embase till June 1st 2015. All studies were graded on their quality. The search resulted in 124 studies, of which 17 were included: Ten reported on return to sports, 17 reported on risk factors and nine on preventive measures. For return to sports, nine studies mentioned a loss of training of 4-6 weeks. The shortest period was one week and the longest 16 weeks. For risk factors, insufficient or conflicting evidence was found for changes in the training program, incorrect rowing technique, female gender, low bone mineral density, inadequate equipment, and training type. For prevention, gradual changes in the training program, alertness on the part of coaches and clinicians, and supplementation of diet and hormones are suggested as effective measures. However, no effect studies have been found. The main outcome of this review on RSFs is that little evidence is available on return to sports, risk factors and preventive measures. Coaches and clinicians should carefully guide and assist rowers suffering from RSFs in off training and in the subsequent training period to regain their pre-injury level.

  13. Fracture Mechanics

    Zehnder, Alan T


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

  14. Fractures, stress and fluid flow prior to stimulation of well 27-15, Desert Peak, Nevada, EGS project

    Davatzes, Nicholas C.; Hickman, Stephen H.


    A suite of geophysical logs has been acquired for structural, fluid flow and stress analysis of well 27-15 in the Desert Peak Geothermal Field, Nevada, in preparation for stimulation and development of an Enhanced Geothermal System (EGS). Advanced Logic Technologies Borehole Televiewer (BHTV) and Schlumberger Formation MicroScanner (FMS) image logs reveal extensive drilling-induced tensile fractures, showing that the current minimum compressive horizontal stress, Shmin, in the vicinity of well 27-15 is oriented along an azimuth of 114±17°. This orientation is consistent with the dip direction of recently active normal faults mapped at the surface and with extensive sets of fractures and some formation boundaries seen in the BHTV and FMS logs. Temperature and spinner flowmeter surveys reveal several minor flowing fractures that are well oriented for normal slip, although over-all permeability in the well is quite low. These results indicate that well 27-15 is a viable candidate for EGS stimulation and complements research by other investigators including cuttings analysis, a reflection seismic survey, pressure transient and tracer testing, and micro-seismic monitoring.


    Daniel R. Burns; M. Nafi Toksoz


    Numerical modeling and field data tests are presented on the Transfer Function/Scattering Index Method for estimating fracture orientation and density in subsurface reservoirs from the ''coda'' or scattered energy in the seismic trace. Azimuthal stacks indicate that scattered energy is enhanced along the fracture strike direction. A transfer function method is used to more effectively indicate fracture orientation. The transfer function method, which involves a comparison of the seismic signature above and below a reservoir interval, effectively eliminates overburden effects and acquisition imprints in the analysis. The transfer function signature is simplified into a scattering index attribute value that gives fracture orientation and spatial variations of the fracture density within a field. The method is applied to two field data sets, a 3-D Ocean Bottom Cable (OBC) seismic data set from an offshore fractured carbonate reservoir in the Adriatic Sea and a 3-D seismic data set from an onshore fractured carbonate field in the Middle East. Scattering index values are computed in both fields at the reservoir level, and the results are compared to borehole breakout data and Formation MicroImager (FMI) logs in nearby wells. In both cases the scattering index results are in very good agreement with the well data. Field data tests and well validation will continue. In the area of technology transfer, we have made presentations of our results to industry groups at MIT technical review meetings, international technical conferences, industry workshops, and numerous exploration and production company visits.

  16. Spontaneous bilateral fracture of patella.

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


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

  17. Stress fracture of hamate's hook: case report with emphasis to the imaging findings; Fratura de stress do gancho do hamato: relato de caso com enfase aos achados de imagem

    Carvalho, Leonardo Fontenelle de [Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro, RJ (Brazil); Vianna, Evandro Miguelote; Domingues, Romulo; Domingues, Romeu Cortes [Clinicas Multimagem, Rio de Janeiro, RJ (Brazil); Metsavaht, Leonardo [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)]. E-mail:


    Stress fractures of the hook of the hamate are related to sports that use devices such as golf clubs, rackets and baseball bats. Because usually there is no history of obvious trauma, the diagnosis necessitates better knowledge of the lesion and high index of suspicion. The authors report a case of stress fracture of the hook of the hamate in a golf player with diagnosis and follow-up done with magnetic resonance and multislice computer tomography. (author)

  18. Experimental Investigation on the Basic Law of the Fracture Spatial Morphology for Water Pressure Blasting in a Drillhole Under True Triaxial Stress

    Huang, Bingxiang; Li, Pengfeng


    The present literature on the morphology of water pressure blasting fractures in drillholes is not sufficient and does not take triaxial confining stress into account. Because the spatial morphology of water pressure blasting fractures in drillholes is not clear, the operations lack an exact basis. Using a large true triaxial water pressure blasting experimental system and an acoustic emission 3-D positioning system, water pressure blasting experiments on cement mortar test blocks (300 mm × 300 mm × 300 mm) were conducted to study the associated basic law of the fracture spatial morphology. The experimental results show that water pressure blasting does not always generate bubble pulsation. After water pressure blasting under true triaxial stress, a crushed compressive zone and a blasting fracture zone are formed from the inside, with the blasting section of the naked drillhole as the center, to the outside. The shape of the outer edges of the two zones is ellipsoidal. The range of the blasting fracture is large in the radial direction of the drillhole, where the surrounding pressure is large, i.e., the range of the blasting fracture in the drillhole radial cross-section is approximately ellipsoidal. The rock near the drillhole wall is affected by a tensile stress wave caused by the test block boundary reflection, resulting in more flake fractures appearing in the fracturing crack surface in the drillhole axial direction and parallel to the boundary surface. The flake fracture is thin, presenting a small-range flake fracture. The spatial morphology of the water pressure blasting fracture in the drillhole along the axial direction is similar to a wide-mouth Chinese bottle: the crack extent is large near the drillhole orifice, gradually narrows inward along the drillhole axial direction, and then increases into an approximate ellipsoid in the internal naked blasting section. Based on the causes of the crack generation, the blasting cracks are divided into three

  19. Delirium in elderly individuals with hip fracture: causes, incidence, prevalence, and risk factors Delirium em idosos com fratura de fêmur: causas, incidência, prevalência e fatores de risco

    Maria Elizabet Furlaneto


    Full Text Available OBJECTIVES: To determine the incidence, prevalence, risk factors, and causes of delirium in elderly individuals with hip fractures, as well as the impact of delrium on mortality and length of hospital stay. PATIENTS: One hundred and three patients aged 65 and older with hip fractures were included consecutively between January 2001 and June 2002. METHOD: Delirium was diagnosed using the Confusion Assessment Method, applied within the first 24 hours after admission, and then daily. All patients underwent a global geriatric evaluation including clinical history, physical examination, laboratory tests, surgical risk evaluation, and functional and mental evaluations. Patients with delirium (cases were compared with patients without delirium (controls. RESULTS: Thirty (29.1% patients in this sample met the criteria for delirium, with a prevalence of 16.5% (17/103 and an incidence of 12.6% (13/103. Cognitive and functional deficits had a significant association with delirium, although only cognitive deficit was revealed to be an independent risk factor after analysis with the logistic regression model. The most frequent causes of delirium were drugs and infections. The hospital stay was significantly longer for patients with delirium compared with patients in the control group (26.27 versus 14.38 days, respectively. Mortality showed a tendency to higher levels in patients with delirium during their hospital stay, although with no statistical significance. CONCLUSIONS: Delirium is a frequent complication among hospitalized elderly individuals with hip fractures. It is associated with cognitive and functional deficits, and it is associated with increases the length of hospital stay and mortality.OBJETIVOS: Deteminar a incidência, prevalência, fatores de risco e causas de delirium em idosos com fratura de fêmur, e seu impacto sobre mortalidade e permanência hospitalar. MÉTODOS: Cento e três pacientes com 65 anos e mais com fratura de fêmur foram

  20. Course and predictors of posttraumatic stress among male train drivers after the experience of 'person under the train' incidents.

    Mehnert, Anja; Nanninga, Imke; Fauth, Mathias; Schäfer, Ingo


    The present prospective study aimed to identify the frequency and course of posttraumatic stress symptoms, anxiety, depression, and quality of life in train drivers after the experience of 'person under the train' incidents. Furthermore, associations between predictors of posttraumatic stress stratified by pre-, peri- and posttraumatic factors, psychological distress, quality of life (QoL), sense of coherence, lack of meaning in life, and post-trauma thoughts are analyzed. Patients (100% male, mean age 48 years) were assessed at the beginning (n=73), at the end (n=71) and six months (n=49) after a four-week rehabilitation program and completed validated self-report questionnaires (e.g. Posttraumatic Diagnostic Scale, Hospital Anxiety and Depression Scale, Short-Form Health Survey). Train drivers experienced averagely 1.8 'person under the train' incidents (range 1-8); the majority (81%) was involved in a railway suicide. At the beginning of the rehabilitation, 44% of the patients were classified as having moderate to severe PTSD, and 14% as having severe PTSD. Posttraumatic stress decreased significantly over time (p=.003, η²=.17). We found no significant differences in the course of posttraumatic stress, anxiety, depression, distress and QoL between patients who experienced one or more than one railway related accident or suicide. Anxiety, sense of guilt and sense of alienation emerged as the most important factors in predicting posttraumatic stress six months after rehabilitation (R²=0.55). Findings emphasize the importance of rehabilitation programs for train drivers after railway-related incidents. However, research is needed to develop effective rehabilitation interventions particularly tailored to this patient group. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Case of femoral diaphyseal stress fracture after long-term risedronate administration diagnosed by iliac bone biopsy

    Nagai T


    Full Text Available Takashi Nagai, Keizo Sakamoto, Koji Ishikawa, Emi Saito, Takuma Kuroda, Katsunori Inagaki Department of Orthopaedic Surgery, Showa University School of Medicine, Shinagwa-ku, Tokyo, Japan Abstract: Bisphosphonate excessively inhibits bone resorption and results in pathological fracture of the femur or ilium. The subject of this study was administered risedronate for 7 years; we suspected an easy fracture of the femoral diaphysis. In this study, we report the results of this patient's bone biopsy and bone morphometric analysis. A 76-year-old female patient presented with right femoral pain. Bone mineral density of the anteroposterior surface of the 2nd to 4th lumbar vertebrae (L2-L4 was decreased and levels of bone turnover markers were high. Therefore, we initiated treatment with risedronate. As she continued the medication, urinary levels of cross-linked N-terminal telopeptides of type I collagen and alkaline phosphatase (bone-type isozyme were found to be within the normal ranges. After 7 years of administration, the patient experienced pain when she put weight on the right femur and right femoral pain while walking. Plain radiographic examination revealed polypoid stress fracture-like lesions on the right femoral diaphysis and on the slightly distal-lateral cortical bone. Similar lesions were observed on magnetic resonance imaging and bone scintigraphy. We suspected severely suppressed bone turnover. Bone biopsy was obtained after labeling with tetracycline, and bone morphometric analysis was performed. On microscopic examination, slight double tetracycline labeling was observed. The trabeculae were narrow, and the numbers of osteoblasts and osteoclasts were decreased. Further, rates of bone calcification and bone formation were slow. Hence, we diagnosed fracture as a result of low turnover osteopathy. Risedronate was withdrawn, and Vitamin D3 was administered to improve the bone turnover. At 6 months, abnormal signals on magnetic resonance

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

    Timucin Baykul


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

  3. Rib stress fracture in a male adaptive rower from the arms and shoulders sport class: case report.

    Smoljanovic, Tomislav; Bojanic, Ivan; Pollock, Courtney L; Radonic, Radovan


    Adaptive rowing is rowing or sculling for rowers with a physical disability. It debuted at the Paralympic Games in 2008. In order to ensure an equitable playing field, rowers with similar levels of physical function and disability are classified into different sport classes for competition. Rowers with an inability to use a sliding seat and impaired trunk function resulting in an inability to perform trunk forward and backward lean via hip flexion/extension are assigned to the Arms and Shoulders (AS) class. AS rowers have to use a chest strap set immediately below the chest in order to localize any trunk movement in AS class. Conditions created by adaptations of rowing equipment and technique within the AS class create unique stresses on the upper thoracic region. The following case report demonstrates how etiology and management of a rib stress fracture in an AS rower differs in comparison to able-body rowers. Of significant importance were the limitations imposed on the rower's ability to maintain rowing-specific fitness, due to the nature of the rib stress fracture and requirement to decrease force transmission through the ribs for several weeks. The rower's gradual return to full training was further impacted by obligatory use of the chest strap, which directly applied pressure over the injured area. Protective orthosis for the chest was designed and applied in order to dissipate pressure of the chest strap over the thorax during rowing (most importantly at the catch position) both on the ergometer and in the boat.

  4. Effect of stress-triaxiality on void growth in dynamic fracture of metals: a molecular dynamics study

    Seppala, E T; Belak, J; Rudd, R E


    The effect of stress-triaxiality on growth of a void in a three dimensional single-crystal face-centered-cubic (FCC) lattice has been studied. Molecular dynamics (MD) simulations using an embedded-atom (EAM) potential for copper have been performed at room temperature and using strain controlling with high strain rates ranging from 10{sup 7}/sec to 10{sup 10}/sec. Strain-rates of these magnitudes can be studied experimentally, e.g. using shock waves induced by laser ablation. Void growth has been simulated in three different conditions, namely uniaxial, biaxial, and triaxial expansion. The response of the system in the three cases have been compared in terms of the void growth rate, the detailed void shape evolution, and the stress-strain behavior including the development of plastic strain. Also macroscopic observables as plastic work and porosity have been computed from the atomistic level. The stress thresholds for void growth are found to be comparable with spall strength values determined by dynamic fracture experiments. The conventional macroscopic assumption that the mean plastic strain results from the growth of the void is validated. The evolution of the system in the uniaxial case is found to exhibit four different regimes: elastic expansion; plastic yielding, when the mean stress is nearly constant, but the stress-triaxiality increases rapidly together with exponential growth of the void; saturation of the stress-triaxiality; and finally the failure.

  5. Cumulative incidence and treatment of non-simultaneous bilateral femoral neck fractures in a cohort of one thousand two hundred and fifty patients.

    Burgers, P.T.; Zielinski, S.M.; Mailuhu, A.K.; Heetveld, M.J.; Verhofstad, M.H.J.; Roukema, G.R.; Patka, P.; Poolman, R.W.; Lieshout, E.M. van; Biert, J.


    PURPOSE: In the Netherlands, over 20,000 patients sustain a hip fracture yearly. A first hip fracture is a risk factor for a second, contralateral fracture. Data on the similarity of the treatment of bilateral femoral neck fractures is only scarcely available. The objectives of this study were to

  6. Cumulative incidence and treatment of non-simultaneous bilateral femoral neck fractures in a cohort of one thousand two hundred and fifty patients

    P.T.P.W. Burgers (Paul); S.M. Zielinski (Stephanie); A.K.E. Mailuhu (Adinda); M.J. Heetveld (Martin); M.H.J. Verhofstad (Michiel); G.R. Roukema (Gert); P. Patka (Peter); R.W. Poolman (Rudolf); E.M.M. van Lieshout (Esther)


    textabstractPurpose In the Netherlands, over 20,000 patients sustain a hip fracture yearly. A first hip fracture is a risk factor for a second, contralateral fracture. Data on the similarity of the treatment of bilateral femoral neck fractures is only scarcely available. The objectives of this study


    Daniel R. Burns; M. Nafi Toksoz


    During the past six months we have adapt