Hangman＇s fracture means bilateral pedicle fractures of the axis accompanying displacement and angulations between the body of C2 and C3. The injury is often caused as a result of falling down or being involved in a ...Hangman＇s fracture means bilateral pedicle fractures of the axis accompanying displacement and angulations between the body of C2 and C3. The injury is often caused as a result of falling down or being involved in a vehicular accident. In 1985, based on the classification of Effendi et al, Levine and Edwards proposed a new classification of Hangman＇s fracture according to the mechanism, morphology and stability. The Hangman＇s fracture was classified as type I, II, IIA and III, with type II being the most common of the four types.展开更多
BACKGROUND Fractures of the axis are commonly seen in spinal injuries. Upper cervical fractures are usually managed conservatively. However, the complications due to long-term external immobilization cannot be ignored...BACKGROUND Fractures of the axis are commonly seen in spinal injuries. Upper cervical fractures are usually managed conservatively. However, the complications due to long-term external immobilization cannot be ignored. The traditional open surgery has the disadvantages of too much blood loss and soft tissue injury. The aim of our paper is to introduce a minimally invasive surgical treatment for multiple axis fractures.CASE SUMMARY We report a 40-year-old Chinese male who had severe neck pain and difficult neck movement after falling from 3 meters. X-ray and computed tomography(CT) scan revealed an axis injury consisting of an odontoid Type Ⅲ fracture associated with a Hangman fracture categorized as a Levine-Edwards Type Ⅰ fracture. The patient underwent anterior odontoid screw fixation and posterior percutaneous screw fixation using intraoperative O-arm navigation. Neck pain was markedly improved after surgery. X-rays and CT scan reconstructions of 3-mo follow-up showed good stability and fusion. The range of cervical motion was well preserved.CONCLUSION Anterior odontoid screw fixation and posterior direct C2 percutaneous pedicle screw fixation with the aid of O-arm navigation and neurophysiological monitoring can be an interesting alternative option for complicated multiple axis fractures.展开更多
Thoracolumbar fractures are usually treated by open posterior pedicle screw fixation.However,this procedure involves massive paraspinal muscle stripping,inflicting surgical trauma,and prolonged X-ray exposure.In this ...Thoracolumbar fractures are usually treated by open posterior pedicle screw fixation.However,this procedure involves massive paraspinal muscle stripping,inflicting surgical trauma,and prolonged X-ray exposure.In this study,we observed 127 patients with single-segment injury thoracolumbar fractures.Thirty-six patients were treated by the modified Wiltse’s paraspinal approach with minimally invasive channel system,while 91 patients were treated via traditional posterior approach.Operation time,intraoperative blood loss,intraoperative fluoroscopy frequency,screw placement accuracy,visual analogue scale score,and Cobb’s angle of two groups were compared.The X-ray exposure times were notably reduced(4.2±1.6) in the new approach group(P<0.05).The pedicle screw placement accuracy and Cobb’s angle after surgery were similar in the two groups.We conclude that modified Wiltse’s paraspinal approach w ith spinal minimally invasive channel system surgery can significantly reduce the X-ray exposure times and is an alternative therapy for the thoracolumbar fracture.展开更多
In fractured reservoir beds, fracture characteristics affect seismic wave response. Fractured models based on the Hudson＇s fractured medium theory were constructed in our laboratory by a backfilling technique. For th...In fractured reservoir beds, fracture characteristics affect seismic wave response. Fractured models based on the Hudson＇s fractured medium theory were constructed in our laboratory by a backfilling technique. For the same fracture density, the variations of the velocity and amplitude of the primary wave and shear wave parallel and perpendicular to the fracture were observed by altering the diameter （scale） of the penny-shaped fracture disk. The model test indicated that an increase of fracture scale increased the velocity and amplitude of the primary wave by about 2%. When the shear wave propagated parallel to the fracture, the velocity of the fast shear wave hardly changed, while the velocity of slow shear wave increased by 2.6% with increasing fracture scale. The results indicated that an increase of fracture scale would reduce the degree of anisotropy of the shear wave. The amplitudes of slow shear waves propagating parallel and perpendicular to fractures decreased with increasing fracture scale.展开更多
Association of fracture of trapezium with Bennett'sfracture is very rare and makes reduction and stabilisation more difficult. We are reporting a rare case of Bennett's fracture with fracture of the trapezium ...Association of fracture of trapezium with Bennett'sfracture is very rare and makes reduction and stabilisation more difficult. We are reporting a rare case of Bennett's fracture with fracture of the trapezium and subluxation of the carpo-metacarpal joint(CMC) joint. The patient was a 47-year-old school teacher who fell from his motorbike on his outstretched right dominant hand. Radiographs and computed tomography showed fracture of the trapezium with subluxation of the CMC joint, associated with Bennett's fracture. Open reduction and internal fixation was carried out. Trapezium was reduced first and secured with a 2 mm diameter screw. Bennett's fracture was then reduced and fixed with two per-cutaneously placed Kirchner's wires. CMC was stabilised with percutaneous Kirchner's wires. Latest follow up at 12 mo showed a healed fracture with good reduction of the CMC joint. Clinically patient had no pain and normal extension, abduction and opposition of the thumb. QuickD ASH score was 3.9/100. Thus, fracture of trapezium associated with a Bennett's fracture is a rare injury and if ignored it may lead to poor results. This injury is more challenging to manage than an isolated Bennett's fracture as anatomical reduction of the trapezium with reduction of the first CMC is needed. Fracture of the trapezium should be fixed first as this will provide a stable base for reduction of the Bennett's fracture.展开更多
Hypovitaminosis D and K due to malnutrition or sunlight deprivation,increased bone resorption due to immobilization,low bone mineral density(BMD)and an increased risk of falls may contribute to an increased risk of hi...Hypovitaminosis D and K due to malnutrition or sunlight deprivation,increased bone resorption due to immobilization,low bone mineral density(BMD)and an increased risk of falls may contribute to an increased risk of hip fractures in patients with Parkinson’s disease.The purpose of the present study was to clarify the efficacy of interventions intended to prevent hip fractures in elderly patients with Parkinson’s disease.Pub Med was used to search the literature for randomized controlled trials(RCTs)regarding Parkinson’s disease and hip fractures.The inclusion criteria were 50 or more subjects per group and a study period of 1 year or longer.Five RCTs were identified and the relative risk and95%confidence interval were calculated for individual RCTs.Sunlight exposure increased serum hydroxyvitamin D[25(OH)D]concentration,improved motor function,decreased bone resorption and increased BMD.Alendronate or risedronate with vitamin D supplementation increased serum 25(OH)D concentration,strongly decreased bone resorption and increased BMD.Menatetrenone(vitamin K2)decreased serum undercarboxylated osteocalcin concentration,decreased bone resorption and increased BMD.Sunlight exposure(men and women),menatetrenone(women),alendronate and risedronate with vitamin D supplementation(women)significantly reduced the incidence of hip fractures.The respective RRs(95%confidence intervals)according to the intention-to-treat analysis were 0.27(0.08,0.96),0.13(0.02,0.97),0.29(0.10,0.85)and 0.20(0.06,0.68).Interventions,including sunlight exposure,menatetrenone and oral bisphosphonates with vitamin D supplementation,have a protective effect against hip fractures elderly patients with Parkinson’s disease.展开更多
BACKGROUND: The present study aimed to compare outcome of primary and secondary Illizarov's fi xator application as a treatment method for type III open tibial fractures in terms of nonunion and wound infection.ME...BACKGROUND: The present study aimed to compare outcome of primary and secondary Illizarov's fi xator application as a treatment method for type III open tibial fractures in terms of nonunion and wound infection.METHODS: This prospective study was done in a tertiary care center. Forty-eight type III tibial fractures were treated with Illizarov's apparatus between 2008 and 2011. The patients were divided into two groups depending on the treatment protocol, timing of wound closure and Illizarov's application, primary(n=28) and secondary(n=20).RESULTS: In the primary group, healing was achieved in all 28 patients. The median time to recovery was 24 weeks, and the median number of operations was 3. There were 6 patients with a bone defect. In the secondary group, complete recovery was achieved in 18 out of 20 patients. The median time to recovery was 30 weeks, and the median number of operations 5. There were 9 patients with a bone defect. The median time to recovery and the number of operations were signifi cantly smaller in patients undergoing primary operation. Union was 100% in the primary group and more than 95% in the secondary group. Chronic osteomyelitis persisted in one patient and below amputation was done in one patient in the secondary group.CONCLUSION: Primary wound closure and Illizarov's fixation required a smaller number of operations and shorter time to recovery than secondary wound closure and Illizarov's fi xation, mostly due to a signifi cantly less number of patients with a bone defect in the primary group.展开更多
We present a path morphology method to separate total rock pore space into matrix, fractures and vugs and derive their pore structure spectrum. Thus, we can achieve fine pore evaluation in fracture–vug reservoirs bas...We present a path morphology method to separate total rock pore space into matrix, fractures and vugs and derive their pore structure spectrum. Thus, we can achieve fine pore evaluation in fracture–vug reservoirs based on electric imaging logging data. We automatically identify and extract fracture–vug information from the electric imaging images by adopting a path morphological operator that remains flexible enough to fit rectilinear and slightly curved structures because they are independent of the structuring element shape. The Otsu method was used to extract fracture–vug information from the background noise caused by the matrix. To accommodate the differences in scale and form of the different target regions,including fracture and vug path, operators with different lengths were selected for their recognition and extraction at the corresponding scale. Polynomial and elliptic functions are used to fit the extracted fractures and vugs, respectively, and the fracture–vug parameters are deduced from the fitted edge. Finally, test examples of numerical simulation data and several measured well data have been provided for the verification of the effectiveness and adaptability of the path morphology method in the application of electric imaging logging data processing. This also provides algorithm support for the fine evaluation of fracture–vug reservoirs.展开更多
The effects of plastic deformation and H2 S on fracture toughness of high strength casing steel（C110 steel） were investigated. The studied casing specimens are as follows： original casing, plastic deformation（PD）...The effects of plastic deformation and H2 S on fracture toughness of high strength casing steel（C110 steel） were investigated. The studied casing specimens are as follows： original casing, plastic deformation（PD） casing and PD casing after being immersed in NACE A solution saturated with H2S（PD＋H2S）. Instrumented impact method was employed to evaluate the impact behaviors of the specimens, meanwhile, dynamic fracture toughness（JId） was calculated by using Rice model and Schindler model. The experimental results show that dynamic fracture toughness of the casing decreases after plastic deformation. Compared with that of the original casing and PD casing, the dynamic fracture toughness decreases further when the PD casing immersed in H2 S, moreover, there are ridge-shaped feature and many secondary cracks present on the fracture surface of the specimens. Impact fracture mechanism of the casing is proposed as follows： the plastic deformation results in the increase of defect density of materials where the atomic hydrogen can accumulate in reversible or irreversible traps and even recombine to form molecular hydrogen, subsequently, the casing material toughness decreases greatly.展开更多
The fatigue fracture behavior of four ultrahigh strength steels with different melting processes and therefore different inclusion sizes were studied by using a rotating bar two-point bending fatigue machine in the hi...The fatigue fracture behavior of four ultrahigh strength steels with different melting processes and therefore different inclusion sizes were studied by using a rotating bar two-point bending fatigue machine in the high-cycle regime up to 107 cycles of loading. The fracture surfaces were observed by field emission scanning electron microscopy （FESEM）. It was found that the size of inclusion has significant effect on the fatigue behavior. For AtSI 4340 steel in which the inclusion size is smaller than 5.5 μm, all the fatigue cracks except one did not initiated from inclusion but from specimen surface and conventional S-N curve exists. For 65Si2MnWE and Aermet 100 steels in which the average inclusion sizes are 12.2 and 14.9 μm, respectively, fatigue cracks initiated from inclusions at lower stress amplitudes and stepwise S-N curves were observed. The S-N curve displays a continuous decline and fatigue failures originated from large oxide inclusion for 60Si2CrVA steel in which the average inclusion size is 44.4 pro. In the case of internal inclusion-induced fractures at cycles beyond about 1×10^6 for 65Si2MnWE and 60Si2CrVA steels, inclusion was always found inside the fish-eye and a granular bright facet （GBF） was observed in the vicinity around the inclusion. The GBF sizes increase with increasing the number of cycles to failure Nf in the long-life regime. The values of stress intensity factor range at crack initiation site for the GBF are almost constant with Nf, and are almost equal to that for the surface inclusion and the internal inclusion at cycles lower than about 1×10^6. Neither fish-eye nor GBF was observed for Aermet 100 steel in the present study.展开更多
In this paper the Auerbach＇s scaling law of Hertzian fracture induced by a spherical indenter pressing on a brittle solid is studied. In the analysis, the singular integral equation method is used to analyze the frac...In this paper the Auerbach＇s scaling law of Hertzian fracture induced by a spherical indenter pressing on a brittle solid is studied. In the analysis, the singular integral equation method is used to analyze the fracture behavior of the Hertzian contact problem. The results show that the Auerbach＇s constant sensitively depends on the Poisson＇s ratio, and the effective Auerbach＇s domain is also determined for a given value of the Poisson＇s ratio.展开更多
Parkinson’s disease is a neurodegenerative disorder that is common in older people and is highly associated with depression, anxiety, apathy, psychosis, cognitive impairment, imbalance and sleep disturbances. These p...Parkinson’s disease is a neurodegenerative disorder that is common in older people and is highly associated with depression, anxiety, apathy, psychosis, cognitive impairment, imbalance and sleep disturbances. These patients have an increased risk of fracture compared to the general population. Comprehensive searches of databases are performed to identify reviews about the risk of fractures in this disease. Parkinson’s patients are at increased risk for low bone mineral density due to the effect of drugs, Parkinson’s disease and age factor, leading to an increased risk of falling down and fractures, especially in the hip. So, improved and innovative treatments with the focus on minimizing inadvertent bone resorption with anti-Parkinson’s disease medication will be highly effective in reducing fear of the disease and providing the patient with a better quality of life.展开更多
BACKGROUND Hoffa’s fracture is a coronal-oriented fracture of the femoral condyle.It is rarely observed in pediatric patients that isolated coronal fracture of the medial femoral condyle accompanies an intact lateral...BACKGROUND Hoffa’s fracture is a coronal-oriented fracture of the femoral condyle.It is rarely observed in pediatric patients that isolated coronal fracture of the medial femoral condyle accompanies an intact lateral femoral condyle.Only a few cases involving Hoffa’s fracture of the medial femoral condyle have been reported in patients with undeveloped skeletons.Such a fracture cannot be observed by routine imaging examinations,thus resulting in possible misdiagnosis and further treatment challenges.CASE SUMMARY A 5-year-old boy with Hoffa’s fracture of the medial femoral condyle suffered from right knee pain and severe swelling after being hit by a heavy object.The patient was misdiagnosed and initially treated in a local primary healthcare center.No improvement in his right knee’s extension was observed following conservative treatment for 2 wk.The patient was transferred to our hospital,rediagnosed using arthroscopy,and underwent open reduction and internal fixation.The therapeutic outcome was satisfactory with the screws removed 7 mo after fixation.At the final follow-up of 40 mo,the range of motion in the knee had recovered.There was no varus-valgus instability.CONCLUSION Hoffa’s fracture is rarely seen in children aged 5 years,let alone in the medial condyle,and can easily be misdiagnosed due to limited physical and imaging examinations.Suspected Hoffa’s fracture in preschool children should be confirmed based on arthroscopic findings.Open reduction and internal fixation should be performed to protect the articular surface and prevent long-term complications.展开更多
For four centuries now, southern Ghana has been known to be seismically active, and there is no clear geological explanation for the cause of the seismicity. By evaluating new field data and information with re-interp...For four centuries now, southern Ghana has been known to be seismically active, and there is no clear geological explanation for the cause of the seismicity. By evaluating new field data and information with re-interpreted historical earthquake data of southern Ghana, the nature of the seismicity of southern Ghana has been elucidated. The mutual connection between the earthquake epicentres and the remote causes by Mid-Atlantic transform faults and fracture zones has been established. The seismic regions of southern Ghana have been linked separately to tectonic faults and activities of the St. Paul’s and Romanche transform-fracture zone systems offshore in the Gulf of Guinea to onshore. It is concluded that the seismicity of southern Ghana is due to tectonic activities of the St. Paul’s and Romanche transform-fracture systems. The Accra region earthquakes originate from reactivation of faults in the Romanche transform-fracture zone, and propagate onshore through Accra and environs. The Axim region earthquakes come from reactivated faults linked to the St Paul’s fracture zone, which go through southern Cote D’Ivoire to Ghana. Seismotectonic movements along the St Paul’s transform and fracture zones have quieted since 1879. But movement along the Romanche Transform fault and Fracture zone is active, causing ongoing seismicity of southern Ghana.展开更多
Pyle’s disease is a rare genetic skeletal disorder also known as Metaphyseal dysplasia. A case of 36 yrs old female with fracture supracondylar femur in Pyle’s disease is presented. She had mild facial dysmorphism, ...Pyle’s disease is a rare genetic skeletal disorder also known as Metaphyseal dysplasia. A case of 36 yrs old female with fracture supracondylar femur in Pyle’s disease is presented. She had mild facial dysmorphism, dental malformation & mild genu valgum. Skeletal radiology revealed the characteristic Erlenmeyer flask sign at distal femoral and proximal tibial metaphysis. The fracture supracondylar femur was treated with interlocking nail. The fracture was united in sixteen weeks period. The patient is followed up for two years. The aim of the case report is the rarity of the condition with fracture supracondylar femur in adult female successfully treated with interlocking nail.展开更多
Background: Fracture of distal radius with involvement of the ulnar styloid process is a common clinical problem. It can be treated conservatively, usually involving wrist immobilization in plaster cast or surgically....Background: Fracture of distal radius with involvement of the ulnar styloid process is a common clinical problem. It can be treated conservatively, usually involving wrist immobilization in plaster cast or surgically. A key method of surgical fixation is external fixation by distractor. Distractor can be applied either only on the radial side or on both ulnar and radial sides. Materials and Methods: A prospective randomized and comparative study of 1 year duration was conducted on 32 patients admitted in the Department of Orthopaedics of BSMC & H in the age group of 20 to 75 years old with AO types B and C distal radius fracture along with involvement of the ulnar styloid process. The parameters studied were restoration of radial length, restoration of radial angle, intracarpal step-off and palmar tilt which were statistically evaluated and Fisher’s exact test was performed. The two tailed P-value was calculated and both the groups were statistically compared. Results: In our study, 37.5% patients in Group A and 81.25% in Group B had a radial difference Table 1, Chart 1). 43.75% patients in Group A and 87.5% in Group B had radial angle Table 2, Chart 2). 31.25% in Group A and 75% had intra carpal step off Table 3, Chart 3). 62.5% had an abnormal palmar tilt in Group A while only 6.25% had an abnormal palmar tilt in Group B which is extremely statistically significant. On an average, 2 mm of distraction was required in 75% patients of Group A while only 30% patients in Group B required distraction (Table 4, Chart 4). Conclusion: In our study, the radial difference, radial angle, intra carpal step off and palmar tilt returned significantly to normal in the patients treated with distractor on radial side only when compared with distractor application on both radial and ulnar sides for distal radius fracture with ulnar styloid process involvement. Also post-operative distraction required under image intensifier was higher in the group treated with distractor on either side than those with distractor only on radial side.展开更多
文摘Hangman＇s fracture means bilateral pedicle fractures of the axis accompanying displacement and angulations between the body of C2 and C3. The injury is often caused as a result of falling down or being involved in a vehicular accident. In 1985, based on the classification of Effendi et al, Levine and Edwards proposed a new classification of Hangman＇s fracture according to the mechanism, morphology and stability. The Hangman＇s fracture was classified as type I, II, IIA and III, with type II being the most common of the four types.
文摘BACKGROUND Fractures of the axis are commonly seen in spinal injuries. Upper cervical fractures are usually managed conservatively. However, the complications due to long-term external immobilization cannot be ignored. The traditional open surgery has the disadvantages of too much blood loss and soft tissue injury. The aim of our paper is to introduce a minimally invasive surgical treatment for multiple axis fractures.CASE SUMMARY We report a 40-year-old Chinese male who had severe neck pain and difficult neck movement after falling from 3 meters. X-ray and computed tomography(CT) scan revealed an axis injury consisting of an odontoid Type Ⅲ fracture associated with a Hangman fracture categorized as a Levine-Edwards Type Ⅰ fracture. The patient underwent anterior odontoid screw fixation and posterior percutaneous screw fixation using intraoperative O-arm navigation. Neck pain was markedly improved after surgery. X-rays and CT scan reconstructions of 3-mo follow-up showed good stability and fusion. The range of cervical motion was well preserved.CONCLUSION Anterior odontoid screw fixation and posterior direct C2 percutaneous pedicle screw fixation with the aid of O-arm navigation and neurophysiological monitoring can be an interesting alternative option for complicated multiple axis fractures.
基金financially supported by the National Natural Science Foundation of China(Grant No.81672152 and No.81871773)the Jiangsu Natural Science Foundation(Grant No.BE2018132)。
文摘Thoracolumbar fractures are usually treated by open posterior pedicle screw fixation.However,this procedure involves massive paraspinal muscle stripping,inflicting surgical trauma,and prolonged X-ray exposure.In this study,we observed 127 patients with single-segment injury thoracolumbar fractures.Thirty-six patients were treated by the modified Wiltse’s paraspinal approach with minimally invasive channel system,while 91 patients were treated via traditional posterior approach.Operation time,intraoperative blood loss,intraoperative fluoroscopy frequency,screw placement accuracy,visual analogue scale score,and Cobb’s angle of two groups were compared.The X-ray exposure times were notably reduced(4.2±1.6) in the new approach group(P<0.05).The pedicle screw placement accuracy and Cobb’s angle after surgery were similar in the two groups.We conclude that modified Wiltse’s paraspinal approach w ith spinal minimally invasive channel system surgery can significantly reduce the X-ray exposure times and is an alternative therapy for the thoracolumbar fracture.
文摘In fractured reservoir beds, fracture characteristics affect seismic wave response. Fractured models based on the Hudson＇s fractured medium theory were constructed in our laboratory by a backfilling technique. For the same fracture density, the variations of the velocity and amplitude of the primary wave and shear wave parallel and perpendicular to the fracture were observed by altering the diameter （scale） of the penny-shaped fracture disk. The model test indicated that an increase of fracture scale increased the velocity and amplitude of the primary wave by about 2%. When the shear wave propagated parallel to the fracture, the velocity of the fast shear wave hardly changed, while the velocity of slow shear wave increased by 2.6% with increasing fracture scale. The results indicated that an increase of fracture scale would reduce the degree of anisotropy of the shear wave. The amplitudes of slow shear waves propagating parallel and perpendicular to fractures decreased with increasing fracture scale.
文摘Association of fracture of trapezium with Bennett'sfracture is very rare and makes reduction and stabilisation more difficult. We are reporting a rare case of Bennett's fracture with fracture of the trapezium and subluxation of the carpo-metacarpal joint(CMC) joint. The patient was a 47-year-old school teacher who fell from his motorbike on his outstretched right dominant hand. Radiographs and computed tomography showed fracture of the trapezium with subluxation of the CMC joint, associated with Bennett's fracture. Open reduction and internal fixation was carried out. Trapezium was reduced first and secured with a 2 mm diameter screw. Bennett's fracture was then reduced and fixed with two per-cutaneously placed Kirchner's wires. CMC was stabilised with percutaneous Kirchner's wires. Latest follow up at 12 mo showed a healed fracture with good reduction of the CMC joint. Clinically patient had no pain and normal extension, abduction and opposition of the thumb. QuickD ASH score was 3.9/100. Thus, fracture of trapezium associated with a Bennett's fracture is a rare injury and if ignored it may lead to poor results. This injury is more challenging to manage than an isolated Bennett's fracture as anatomical reduction of the trapezium with reduction of the first CMC is needed. Fracture of the trapezium should be fixed first as this will provide a stable base for reduction of the Bennett's fracture.
文摘Hypovitaminosis D and K due to malnutrition or sunlight deprivation,increased bone resorption due to immobilization,low bone mineral density(BMD)and an increased risk of falls may contribute to an increased risk of hip fractures in patients with Parkinson’s disease.The purpose of the present study was to clarify the efficacy of interventions intended to prevent hip fractures in elderly patients with Parkinson’s disease.Pub Med was used to search the literature for randomized controlled trials(RCTs)regarding Parkinson’s disease and hip fractures.The inclusion criteria were 50 or more subjects per group and a study period of 1 year or longer.Five RCTs were identified and the relative risk and95%confidence interval were calculated for individual RCTs.Sunlight exposure increased serum hydroxyvitamin D[25(OH)D]concentration,improved motor function,decreased bone resorption and increased BMD.Alendronate or risedronate with vitamin D supplementation increased serum 25(OH)D concentration,strongly decreased bone resorption and increased BMD.Menatetrenone(vitamin K2)decreased serum undercarboxylated osteocalcin concentration,decreased bone resorption and increased BMD.Sunlight exposure(men and women),menatetrenone(women),alendronate and risedronate with vitamin D supplementation(women)significantly reduced the incidence of hip fractures.The respective RRs(95%confidence intervals)according to the intention-to-treat analysis were 0.27(0.08,0.96),0.13(0.02,0.97),0.29(0.10,0.85)and 0.20(0.06,0.68).Interventions,including sunlight exposure,menatetrenone and oral bisphosphonates with vitamin D supplementation,have a protective effect against hip fractures elderly patients with Parkinson’s disease.
文摘BACKGROUND: The present study aimed to compare outcome of primary and secondary Illizarov's fi xator application as a treatment method for type III open tibial fractures in terms of nonunion and wound infection.METHODS: This prospective study was done in a tertiary care center. Forty-eight type III tibial fractures were treated with Illizarov's apparatus between 2008 and 2011. The patients were divided into two groups depending on the treatment protocol, timing of wound closure and Illizarov's application, primary(n=28) and secondary(n=20).RESULTS: In the primary group, healing was achieved in all 28 patients. The median time to recovery was 24 weeks, and the median number of operations was 3. There were 6 patients with a bone defect. In the secondary group, complete recovery was achieved in 18 out of 20 patients. The median time to recovery was 30 weeks, and the median number of operations 5. There were 9 patients with a bone defect. The median time to recovery and the number of operations were signifi cantly smaller in patients undergoing primary operation. Union was 100% in the primary group and more than 95% in the secondary group. Chronic osteomyelitis persisted in one patient and below amputation was done in one patient in the secondary group.CONCLUSION: Primary wound closure and Illizarov's fixation required a smaller number of operations and shorter time to recovery than secondary wound closure and Illizarov's fi xation, mostly due to a signifi cantly less number of patients with a bone defect in the primary group.
基金granted access to projects supported by the National Major Fundamental Research Program of China ‘‘On basic research problems in applied geophysics for deep oil and gas fields’’(Grant Number 2013CB228605)CNPC Science and Technology Project(Grant Number 2016A-3303)and CNPC Logging Project(Grant Number 2017E-15)
文摘We present a path morphology method to separate total rock pore space into matrix, fractures and vugs and derive their pore structure spectrum. Thus, we can achieve fine pore evaluation in fracture–vug reservoirs based on electric imaging logging data. We automatically identify and extract fracture–vug information from the electric imaging images by adopting a path morphological operator that remains flexible enough to fit rectilinear and slightly curved structures because they are independent of the structuring element shape. The Otsu method was used to extract fracture–vug information from the background noise caused by the matrix. To accommodate the differences in scale and form of the different target regions,including fracture and vug path, operators with different lengths were selected for their recognition and extraction at the corresponding scale. Polynomial and elliptic functions are used to fit the extracted fractures and vugs, respectively, and the fracture–vug parameters are deduced from the fitted edge. Finally, test examples of numerical simulation data and several measured well data have been provided for the verification of the effectiveness and adaptability of the path morphology method in the application of electric imaging logging data processing. This also provides algorithm support for the fine evaluation of fracture–vug reservoirs.
基金Funded by the Construction of Key Disciplines for Young Teacher Science Foundation of the Southwest Petroleum University(No.P209)the Research Fund for the Doctoral Program of Higher Education(No.20105121120002)the National Natural Science Foundation of China(Nos.51004084 and 51374177)
文摘The effects of plastic deformation and H2 S on fracture toughness of high strength casing steel（C110 steel） were investigated. The studied casing specimens are as follows： original casing, plastic deformation（PD） casing and PD casing after being immersed in NACE A solution saturated with H2S（PD＋H2S）. Instrumented impact method was employed to evaluate the impact behaviors of the specimens, meanwhile, dynamic fracture toughness（JId） was calculated by using Rice model and Schindler model. The experimental results show that dynamic fracture toughness of the casing decreases after plastic deformation. Compared with that of the original casing and PD casing, the dynamic fracture toughness decreases further when the PD casing immersed in H2 S, moreover, there are ridge-shaped feature and many secondary cracks present on the fracture surface of the specimens. Impact fracture mechanism of the casing is proposed as follows： the plastic deformation results in the increase of defect density of materials where the atomic hydrogen can accumulate in reversible or irreversible traps and even recombine to form molecular hydrogen, subsequently, the casing material toughness decreases greatly.
基金the National Key Basic Research and Development Program of China under grant No.2004CB619104.
文摘The fatigue fracture behavior of four ultrahigh strength steels with different melting processes and therefore different inclusion sizes were studied by using a rotating bar two-point bending fatigue machine in the high-cycle regime up to 107 cycles of loading. The fracture surfaces were observed by field emission scanning electron microscopy （FESEM）. It was found that the size of inclusion has significant effect on the fatigue behavior. For AtSI 4340 steel in which the inclusion size is smaller than 5.5 μm, all the fatigue cracks except one did not initiated from inclusion but from specimen surface and conventional S-N curve exists. For 65Si2MnWE and Aermet 100 steels in which the average inclusion sizes are 12.2 and 14.9 μm, respectively, fatigue cracks initiated from inclusions at lower stress amplitudes and stepwise S-N curves were observed. The S-N curve displays a continuous decline and fatigue failures originated from large oxide inclusion for 60Si2CrVA steel in which the average inclusion size is 44.4 pro. In the case of internal inclusion-induced fractures at cycles beyond about 1×10^6 for 65Si2MnWE and 60Si2CrVA steels, inclusion was always found inside the fish-eye and a granular bright facet （GBF） was observed in the vicinity around the inclusion. The GBF sizes increase with increasing the number of cycles to failure Nf in the long-life regime. The values of stress intensity factor range at crack initiation site for the GBF are almost constant with Nf, and are almost equal to that for the surface inclusion and the internal inclusion at cycles lower than about 1×10^6. Neither fish-eye nor GBF was observed for Aermet 100 steel in the present study.
基金supported by the National Natural Science Foundation of China(No.10772058)
文摘In this paper the Auerbach＇s scaling law of Hertzian fracture induced by a spherical indenter pressing on a brittle solid is studied. In the analysis, the singular integral equation method is used to analyze the fracture behavior of the Hertzian contact problem. The results show that the Auerbach＇s constant sensitively depends on the Poisson＇s ratio, and the effective Auerbach＇s domain is also determined for a given value of the Poisson＇s ratio.
文摘Parkinson’s disease is a neurodegenerative disorder that is common in older people and is highly associated with depression, anxiety, apathy, psychosis, cognitive impairment, imbalance and sleep disturbances. These patients have an increased risk of fracture compared to the general population. Comprehensive searches of databases are performed to identify reviews about the risk of fractures in this disease. Parkinson’s patients are at increased risk for low bone mineral density due to the effect of drugs, Parkinson’s disease and age factor, leading to an increased risk of falling down and fractures, especially in the hip. So, improved and innovative treatments with the focus on minimizing inadvertent bone resorption with anti-Parkinson’s disease medication will be highly effective in reducing fear of the disease and providing the patient with a better quality of life.
文摘BACKGROUND Hoffa’s fracture is a coronal-oriented fracture of the femoral condyle.It is rarely observed in pediatric patients that isolated coronal fracture of the medial femoral condyle accompanies an intact lateral femoral condyle.Only a few cases involving Hoffa’s fracture of the medial femoral condyle have been reported in patients with undeveloped skeletons.Such a fracture cannot be observed by routine imaging examinations,thus resulting in possible misdiagnosis and further treatment challenges.CASE SUMMARY A 5-year-old boy with Hoffa’s fracture of the medial femoral condyle suffered from right knee pain and severe swelling after being hit by a heavy object.The patient was misdiagnosed and initially treated in a local primary healthcare center.No improvement in his right knee’s extension was observed following conservative treatment for 2 wk.The patient was transferred to our hospital,rediagnosed using arthroscopy,and underwent open reduction and internal fixation.The therapeutic outcome was satisfactory with the screws removed 7 mo after fixation.At the final follow-up of 40 mo,the range of motion in the knee had recovered.There was no varus-valgus instability.CONCLUSION Hoffa’s fracture is rarely seen in children aged 5 years,let alone in the medial condyle,and can easily be misdiagnosed due to limited physical and imaging examinations.Suspected Hoffa’s fracture in preschool children should be confirmed based on arthroscopic findings.Open reduction and internal fixation should be performed to protect the articular surface and prevent long-term complications.
文摘For four centuries now, southern Ghana has been known to be seismically active, and there is no clear geological explanation for the cause of the seismicity. By evaluating new field data and information with re-interpreted historical earthquake data of southern Ghana, the nature of the seismicity of southern Ghana has been elucidated. The mutual connection between the earthquake epicentres and the remote causes by Mid-Atlantic transform faults and fracture zones has been established. The seismic regions of southern Ghana have been linked separately to tectonic faults and activities of the St. Paul’s and Romanche transform-fracture zone systems offshore in the Gulf of Guinea to onshore. It is concluded that the seismicity of southern Ghana is due to tectonic activities of the St. Paul’s and Romanche transform-fracture systems. The Accra region earthquakes originate from reactivation of faults in the Romanche transform-fracture zone, and propagate onshore through Accra and environs. The Axim region earthquakes come from reactivated faults linked to the St Paul’s fracture zone, which go through southern Cote D’Ivoire to Ghana. Seismotectonic movements along the St Paul’s transform and fracture zones have quieted since 1879. But movement along the Romanche Transform fault and Fracture zone is active, causing ongoing seismicity of southern Ghana.
文摘Pyle’s disease is a rare genetic skeletal disorder also known as Metaphyseal dysplasia. A case of 36 yrs old female with fracture supracondylar femur in Pyle’s disease is presented. She had mild facial dysmorphism, dental malformation & mild genu valgum. Skeletal radiology revealed the characteristic Erlenmeyer flask sign at distal femoral and proximal tibial metaphysis. The fracture supracondylar femur was treated with interlocking nail. The fracture was united in sixteen weeks period. The patient is followed up for two years. The aim of the case report is the rarity of the condition with fracture supracondylar femur in adult female successfully treated with interlocking nail.
文摘Background: Fracture of distal radius with involvement of the ulnar styloid process is a common clinical problem. It can be treated conservatively, usually involving wrist immobilization in plaster cast or surgically. A key method of surgical fixation is external fixation by distractor. Distractor can be applied either only on the radial side or on both ulnar and radial sides. Materials and Methods: A prospective randomized and comparative study of 1 year duration was conducted on 32 patients admitted in the Department of Orthopaedics of BSMC & H in the age group of 20 to 75 years old with AO types B and C distal radius fracture along with involvement of the ulnar styloid process. The parameters studied were restoration of radial length, restoration of radial angle, intracarpal step-off and palmar tilt which were statistically evaluated and Fisher’s exact test was performed. The two tailed P-value was calculated and both the groups were statistically compared. Results: In our study, 37.5% patients in Group A and 81.25% in Group B had a radial difference Table 1, Chart 1). 43.75% patients in Group A and 87.5% in Group B had radial angle Table 2, Chart 2). 31.25% in Group A and 75% had intra carpal step off Table 3, Chart 3). 62.5% had an abnormal palmar tilt in Group A while only 6.25% had an abnormal palmar tilt in Group B which is extremely statistically significant. On an average, 2 mm of distraction was required in 75% patients of Group A while only 30% patients in Group B required distraction (Table 4, Chart 4). Conclusion: In our study, the radial difference, radial angle, intra carpal step off and palmar tilt returned significantly to normal in the patients treated with distractor on radial side only when compared with distractor application on both radial and ulnar sides for distal radius fracture with ulnar styloid process involvement. Also post-operative distraction required under image intensifier was higher in the group treated with distractor on either side than those with distractor only on radial side.
