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1.
BACKGROUND: In 1989, a Boeing 737-400 aircraft crashed at Kegworth, near Nottingham, England. The survivors suffered a large number of pelvic and lower limb injuries, and approximately one-third of the passengers died. Subsequent research has suggested that the "brace-for-impact" position that passengers are advised to adopt prior to a crash landing might be modified in order to reduce the incidence of such injuries. The aim of this research was to evaluate biomechanically such a modified crash brace position. HYPOTHESIS: A modified brace position would help to prevent injuries to some passengers in the event of an impact aircraft accident. METHODS: Impact testing on forward-facing seats was performed at the Royal Air Force Institute of Aviation Medicine, Farnborough, England. Aircraft seats, mounted on a sled, were propelled down a track to impact at -16 Gx. A test dummy was used as the experimental model. Four dummy positions were investigated: a) upper torso braced forward and lower legs inclined slightly rearward of the vertical; b) upper torso braced forward and lower legs inclined forward; c) upper torso upright and lower legs inclined slightly rearward of the vertical; and d) upper torso upright and lower legs inclined forward. The impact pulses used were based on Federal Aviation Administration guidelines. Transducers located in the head, spine, and lower limbs of the dummy recorded the forces to which each body segment was exposed during the impact. These forces were compared for each brace position. RESULTS: Impact testing revealed that the risk of a head injury as defined by the head injury criterion was greater in the upright position than in the braced forward position. The risk of injury to the lower limbs was dependent in part on the flailing behavior of the limbs. Flailing did not occur when the dummy was placed in a braced, legs-back position. CONCLUSIONS: A modified brace position would involve passengers sitting with the upper torso inclined forward so that the passenger's head rested against the structure in front, if possible. The legs would be positioned with the feet resting on the floor in a position slightly behind the knee. The position differs from those previously recommended in that the feet are positioned behind the knee. This study suggests that such a position would reduce the potential for head and lower limb injury in some passengers, given that only a single seat type and single size of occupant have been evaluated. Standardization to such a position would improve passenger understanding and compliance. Such a recommendation should not obscure the fact that an occupant seated in a forward-facing aircraft seat, restrained only by a lap belt, is exposed to considerable forces during an impact accident. Such forces are capable of producing injuries in the femur, pelvis, and lumbar spine.  相似文献   

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Motor vehicle accidents are the primary nonobstetric cause of maternal and subsequent fetal mortality. We present a case in which blunt abdominal trauma sustained by a pregnant woman in a motor vehicle accident caused extensive intrathoracic fetal injuries consisting of bilateral hemothorax, severe bilateral interstitial pulmonary hemorrhages, hemopericardium, and subepicardial hemorrhages, in addition to fetal cranial injuries. To the best of our knowledge, this is the first report of fetal intrathoracic injuries sustained with blunt maternal trauma. The underlying mechanism of intrathoracic trauma was thought to be similar to that of blast injury with transmission of excessive hydrostatic forces throughout the amniotic fluid with severe impact on the elastic fetal chest. This case supports the concept of in utero blast injury to the fetus as a possible cause for fetal soft tissue trauma associated with blunt trauma to the maternal abdomen.  相似文献   

4.
OBJECTIVE: To determine the prevalence of severe psychological trauma --that is, post-traumatic stress disorder--in children involved in everyday road traffic accidents. DESIGN: 12 month prospective study. SETTING: Accident and emergency department, Royal United Hospital, Bath. SUBJECTS: 119 children aged 5-18 years involved in road traffic accidents and 66 children who sustained sports injuries. MAIN OUTCOME MEASURE: Presence of appreciable psychological distress; fulfillment of diagnostic criteria for post-traumatic stress disorder. RESULTS: Post-traumatic stress disorder was found in 41 (34.5%) children involved in road traffic accidents but only two (3.0%) who sustained sports injuries. The presence of post-traumatic stress disorder was not related to the type of accident, age of the child, or the nature of injuries but was significantly associated with sex, previous experience of trauma, and subjective appraisal of threat to life. None of the children had received any psychological help at the time of assessment. CONCLUSIONS: One in three children involved in road traffic accidents was found to suffer from post-traumatic stress disorder when they were assessed 6 weeks after their accident. The psychological needs of such children after such accidents remain largely unrecognised.  相似文献   

5.
Based on a population of 122 severely injured patients the causes of paragliding accidents and the patterns of injury are analyzed. A questionnaire is used to establish a sport-specific profile for the paragliding pilot. The lower limbs (55.7%) and the lower parts of the spine (45.9%) are the most frequently injured parts of the body. There is a high risk of multiple injuries after a single accident because of the tremendous axial power. The standard of equipment is good in over 90% of the cases. Insufficient training and failure to take account of geographical and meteorological conditions are the main determinants of accidents sustained by paragliders, most of whom are young. Nevertheless, 80% of our patients want to continue paragliding. Finally some advice is given on how to prevent paragliding accidents and injuries.  相似文献   

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OBJECTIVES: This biomechanical cadaver study was performed to compare the fixation stability of a standard lateral condylar buttress plate with a similar condylar buttress plate with the distal screws locked to the plate. Then the study was repeated with six additional matched femoral pairs to compare the locked plate with a standard 95-degree blade plate. DESIGN: Six matched pairs of mildly osteopenic femurs were selected, and each side was assigned randomly to fixation with either a standard lateral condylar buttress plate or a modified lateral condylar buttress plate with locked distal screws. The experiment was repeated with six additional matched pairs of femurs instrumented with either a modified lateral condylar buttress plate with locked distal screws or a standard 95-degree blade plate. INTERVENTION: The femurs were instrumented, and a gap osteotomy was created at the distal femoral metaphysis. The instrumented femurs were then mechanically tested in axial compression and bending/torsional loading to determine fixation stability; then they were loaded at 1,000 newtons for 10(5) cycles and retested for stability. MAIN OUTCOME MEASUREMENT: The displacement across the osteotomy gap at 100-newton and 1,000-newton axial loads was measured directly for each specimen before and after cycling. In addition, resistance to displacement in bending/torsional loading (newtons/centimeter) was determined from load/displacement curves, before and after cycling. RESULTS: The locked buttress plate provided significantly greater fixation stability than the standard plate both before and after cycling in axial loading. The locked buttress plate also proved significantly more stable in axial loading than the blade plate both before and after cycling. CONCLUSION: A condylar buttress plate with locked screws is a valid concept for improving fixation stability.  相似文献   

7.
在薄壁结构的应用中,屈曲稳定性是影响其承载性能的关键因素,为研究减薄铺层厚度对复合材料薄壁结构局部屈曲行为的影响,本文采用不同厚度(0.125、0.055和0.020 mm)的预浸料制备复合材料薄壁管,实验测试了其在轴压下的局部屈曲行为.实验结果表明,随着铺层厚度减薄,实验采用的正交和均衡两种铺层方式的复合材料薄壁管局部屈曲载荷均随之提高,而屈曲失效模式没有发生改变.力学分析表明,铺层厚度减薄后,管壁弯曲刚度的改变和层间剪切应力分布对薄壁管局部屈曲载荷提高有重要影响.采用薄铺层制备复合材料薄壁结构件能够有效提高其局部屈曲能力.  相似文献   

8.
AIMS: To analyze the association between alcohol intake and the severity of injuries sustained from traffic accidents on a Mexican highway. DESIGN: An observational unit evaluated drivers involved in auto accidents. SETTING: Mexico-Cuernavaca Highway, Mexico. A 60 km-long road with many altitude variations and sharp curves. PARTICIPANTS: Three hundred and eighty-six drivers involved in traffic accidents between March and September, 1994. MEASUREMENTS: A questionnaire was applied to the driver, an occupant or witness at the site of the accident to collect information about the driver, vehicle characteristics, type of accident, day-night occurrence, road section (Mexico-Cuernavaca or Cuernavaca-Mexico) and weather conditions. A physical examination was carried out to determine the presence and severity of injuries. FINDINGS: There were 177 injured people, including 12 deaths, with rates of 67.5 injuries and 4.58 deaths per 10,000 km driven. Variables associated with alcohol intake (p < 0.05) included: severity of injuries, non-use of seat belt, vehicle size and occurrence at night. Risk factors for severe injuries were: alcohol intake (adjusted OR 6.1 CI 95% 1.6-24.0); non-use of seat belt (OR 4.9 CI 2.2-10.8), age < 25 years (OR 3.6 CI 1.0-12.7), age > 54 years (OR 6.0 CI 1.4-25.0), speed > 90 km/h (OR 2.6 CI 1.1-6.3) and occurrence at night (OR 2.6 CI 1.3-5.3). CONCLUSIONS: Alcohol intake is a major risk factor for severe injuries from highway traffic accidents. Its association with other risk factors such as non-use of seat belt and excessive speed suggests the importance of designing interventions aimed at reducing alcohol intake among automobile drivers.  相似文献   

9.
Injuries sustained in schools account for 20-30% of all accident and emergency attendances in school age children. Little information has been available on the epidemiology of school accidents in the United Kingdom. Two years of routine school incident reports were analysed from Renfrew Sub-Region, an area with a school roll of 55,521 children attending 135 schools. Schools returned 1,660 report forms in the two year period, of which 1,440 referred to injuries to school children. The peak incidence of injuries was in the 10-12 year age group. The male:female ratio was 1.37:1. Cuts/ laceration and fractures were the commonest diagnoses reported for both Primary and Secondary Schools. Injuries to face and features were commonest in Primary, and upper limb injuries in Secondary Schools. Uncontrolled areas, e.g. playgrounds, stairways and corridors were the most frequent places of occurrence in Primary Schools (Relative Risk 5.24, 95% C.I. 3.28-8.35). Report accuracy was assessed by comparing one year of school reports in a Local Government District to records in the local District General Hospital. This identified 156 children who had attended hospital as the result of a school accident. Schools overestimated the number of fractures by 27%, but where schools had not provided a diagnosis, 15.4% were identified as fractures in hospital records. Each child seen at the hospital received an average of 2.1 X-rays. Nine children underwent manipulations under general anaesthetic. Seventeen children were admitted to hospital, and the group required 103 outpatient follow-up appointments.  相似文献   

10.
Over a period of one year, all accidents associated with in-line skating (ILS) were surveyed. Sport-specific data was recorded with a standardized questionnaire. The study comprised 66 patients with 75 injuries (48 upper limb, 16 skull, eight lower limb, three trunk). We were looking after 42 male and 24 female patients with an average age of 20 years (5-53 years). Twenty-seven patients (40%) had to be treated as inpatients. Overall, the most frequent injury (one third of all injuries) was forearm fracture close to the wrist (21 radius fractures, four radioulnar fractures). It had to be reset in 20 cases. Additional internal fixation was required in 10 cases (Kirschner wire osteosynthesis, intramedullary nailing or plate osteosynthesis). Only five patients could be treated with plaster cast fixation alone. Most patients with injuries in the vicinity of the wrist were not wearing a wrist protector at the time of the accident. The most frequent reasons given for not wearing protectors was forgetfulness or the high price of protectors. However, there were also two distal radius fractures and a disc injury in the wrist in patients who had been wearing wrist protectors. In most cases, ILS accidents lead to appreciable damage requiring a healing period of several weeks to months (average period of loss of work 41 days). The bfu (advisory center for accident prevention) reckons with 60,000 ILS cases annually in Switzerland. These injuries are thus of great socioeconomic importance. In the future, better risk behavior must be achieved by informing the population (wearing protectors, especially for the wrist and head, attendance of training courses).  相似文献   

11.
Accidents are the leading cause of death in children and a major factor in lost productive life. This case-control study investigates childhood accidents in the home by randomly surveying children presenting to a Dublin Accident and Emergency Department. Risk factors for home accidents are examined by comparing cases (those with accidental injuries sustained at home) with controls. Of the 174 accident attenders, 59.2% were boys; 66% of all surveyed were under 5 years. Cases were more likely to belong to Social Class 5-6 (P < 0.01), their fathers were less likely to be employed (p < 0.01) and mothers were less likely to be working outside the home (P < 0.01). Over 50% of injuries were due to falls (50.8%). Blows and cuts accounted for 22.6% of injuries, while 13% were due to burns, 7.9% were due to poisoning, and 5.7% due to foreign bodies. Children under 5 were more likely than older children to have been supervised at the time of the accident. Most of the injuries were minor. However, 34 children (19.5%) required hospital admission. Measures to prevent accidents at home should be targeted towards those at most risk-parents of pre-school children and the lower social class groups. Accident prevention requires a three-pronged approach i.e. environmental change, enforcement of legislation and educational measures.  相似文献   

12.
As advancements are made in the prevention of automobile fatalities, an increase in the incidence of pelvic and lower extremity injuries has occurred. These remain the leading causes of impairment and loss of years of productive life. Pelvic trauma has a high initial mortality rate when severe. However, with early resuscitation and transport, more survivors arrive in our trauma centers harboring these injuries. Owing to early stabilization and mobilization of the traumatized patient, a decrease in complications in these patients has been noted. Both the trauma surgeon and the orthopedic trauma surgeon should work as a team and remain in continuous communication during the treatment of these patients. Open fractures are among the most difficult problems to manage; early and aggressive decisions can prevent a lifetime of complications and physical impairment. As previously stated, to obtain good outcomes, open fractures must be treated initially at the accident scene followed by timely transport to the trauma center for definitive care. It must be remembered that the golden time to prevent major complications is 6 hours. Intra-articular fractures of the lower extremity involve a major weight bearing joint. Post-traumatic arthritis and impairment develop in joints where joint congruity is not achieved. To preserve normal function, there should be articular congruity, stable fixation, axial alignment with the rest of the extremity, and restoration of full range of motion. Immediate stabilization of long bone fractures has many advantages in the multiply injured patient, such as improved long-term function, prevention of deep venous thrombosis and decubitus ulcer, decreased need for analgesia, and reduction in the incidence of adult respiratory distress syndrome and fat emboli. Patients with femoral shaft fractures should undergo immediate stabilization of the fracture within 24 hours of injury. We have presented a series of orthopedic injuries that have high mortality and high morbidity which, if not treated expediently, yield a high degree of impairment.  相似文献   

13.
A method was developed to study the biomechanical response of the lumbar motion segment (Functional Spinal Unit, FSU) under a dynamic (transient) load in flexion. In order to inflict flexion-distraction types of injuries (lap seat-belt injuries) different load pulses were transferred to the specimen by means of a padded pendulum. The load response of the specimen was measured with a force and moment transducer. The flexion angulation and displacements were determined by means of high-speed photography. Two series of tests were made with ten specimens in each and with two different load pulses: one moderate load pulse (peak acceleration 5 g, rise time 30 ms, duration 150 ms) and one severe load pulse (peak acceleration 12 g, rise time 15 ms, duration 250 ms). The results showed that the moderate load pulse caused residual permanent deformations at a mean bending moment of 140 Nm and a mean shear force of 430 N at a mean flexion angulation of 14 degrees. The severe load pulse caused evident signs of failure of the segments at a mean bending moment of 185 Nm and a mean shear force of 600 N at a mean flexion angulation of 19 degrees. Significant correlations were found between the load response and the size of the specimen, as well as between the load response and the bone mineral content (BMC) in the two adjacent vertebrae. Comparisons with lumbar spine response to static flexion-shear loading indicated that the specimens could withstand higher bending moments before injury occurred during dynamic loading, but the deformations at injury tended to be smaller for dynamic loading.  相似文献   

14.
Our experience with 10 patients who suffered midshaft fractures of the femur and injuries to their ipsilateral hips has resulted in a treatment protocol that we believe can avoid unnecessary complications. The surgical protocol is a three-stage procedure based on (1) intramedullary nailing of the femur with interlocking for preserving the anatomic length and rotation of the femur; (2) treatment of the hip joint injury by means of open reduction and internal fixation of the acetabular fracture and/or reduction and fixation of the fractured femoral neck; and (3) repair of the extensor mechanism. Eight patients received this treatment and had fast recoveries. Union of the femoral fracture and full range of motion of the knee joint were observed within 3 months. In contrast, two patients who had received different surgical treatment had incomplete functional recoveries. This study offers a treatment protocol for ipsilateral disruption of the extensor mechanism, hip joint injury, and midshaft fracture of the femur in the multiply injured patient that can achieve full recovery with no complications. This relatively rare combination of injuries is definitely worthy of special attention.  相似文献   

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Experiments were performed on two patients with custom-made instrumented massive proximal femoral prostheses implanted after tumour resection. In vivo axial forces transmitted along the prostheses were telemetered during level walking, single- and double-leg stance, and isometric exercises of the hip muscles. These activities varied the lever arms available to the external loads: minimum for double-leg stance and maximum for hip isometric exercises. Kinematic, force plate, EMG and telemetered force data were recorded simultaneously. The force magnification ratio (FMR; the ratio of the telemetered axial force to the external force) was calculated. The FMRs ranged from 1.3 (during double-leg stance) to 29.8 (during abductors test), indicating that a major part of the axial force in the long bones is a response to muscle activity, the strength of which depends on the lever arms available to the external loads. From these results, it was shown that the bulk of the bending moment along limbs is transmitted by a combination of tensile forces in muscles and compressive forces in bones, so moments transmitted by the bones are smaller than the limb moments. It was concluded that appropriate simulation of muscle forces is important in experimental or theoretical studies of load transmission along bones.  相似文献   

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A study was made of the role of the fibula in weightbearing and its contribution to ankle joint stability in 10 anatomic specimen lower limbs. On axial loading of the lower limb, the fibula was found to take an average of 17% of a 1500 N axial load. The proportion of the load carried by the fibula increased with the total loading. It also increased when the line of load was displaced laterally and when the ankle joint was in dorsiflexion and decreased when the line of loading shifted medially or the joint was plantar flexed. With loading, the lateral malleolus migrated distally relative to the medial malleolus, except after fibular osteotomy, when it migrated proximally. There was an approximately inverse relationship between proportional fibular loading and distal fibular migration. Cutting the inferior tibiofibular ligament reduced the proportional load in the fibula and increased its distal migration. The interosseous membrane modified the load distribution between the tibia and the fibula, with the distal fibula carrying a higher proportion of the axial load than did the proximal. Surgical repair of a ruptured inferior tibiofibular ligament, using either 1 or 2 screws, was associated with an abnormal pattern of load distribution and fibular displacement.  相似文献   

18.
Pelvic bony injuries are uncommon in children except for avulsion fractures. Medical records and radiographs of 54 children, in whom pelvic fractures were diagnosed from 1974 to 1993, were reviewed. Children 16 years of age and younger who were treated as inpatients were included in this study. Thirty-two patients were boys (59.3%) and 22 were girls (40.7%). In 47 (87.0%) patients, trauma was caused by motor vehicle accidents. The fractures were classified according to the Torode and Zieg classification and the Tile AO/Association for the Study of Internal Fixation classification. Forty-seven (87.0%) children had associated pelvic or extrapelvic injuries. The mean Injury Severity Score was 30.5 (range, 4-66). The AO classification correlated well with the severity of the injury. Eight children (14.8%) died. In most (38 patients = 70.4%) patients, the pelvic bony injury was treated by conservative means. External or internal fixation of the fracture was performed in 16 (29.6%) patients. A followup examination was conducted in 35 of 44 survivors (79.5%; 2 other patients died of unknown causes) with a mean followup of 135 months (range, 18-235 months); 1 additional patient was interviewed by telephone. In this series, long term morbidity was rare and was attributed to severe pelvic ring disruptions, acetabular fractures, or concomitant injuries. It is concluded that in unstable pelvic ring disruptions and acetabular fractures, the principles of management in children should not differ greatly from those in adults. Serious associated pelvic or extrapelvic injuries may pose more management problems than does the pelvic fracture.  相似文献   

19.
Information about the loading of the human acetabulum during walking is necessary for a functional understanding of the morphology of the pelvic girdle and the hip joint as well as for the optimization of endoprosthetic therapy in osteoarthritis. For this purpose, experimental data of the forces acting on the femur in walking taken from the literature [Bergmann et al.: J. Biomech. 1993;26: 969-990] were combined with our own kinematic and morphometric data, to transform the force vectors from the femoral into a pelvic and an acetabular frame. During the walking cycle, the resultant force vector takes a rather constant course relative to the pelvis and its orientation seems to be highly regulated to act within a small range of angles. Only small deviations occur from the angles against the vertical which the resultant peak force forms in the frontal plane (F = 11 degrees, medially orientated) and in the sagittal plane (S = 5 degrees, ventrally orientated). The experimental results form the basis for a model of the incongruous hip joint as an elastic joint, the femoral head being centered between compliant elements.  相似文献   

20.
There is concern that the helmet display unit (HDU) used by AH-64 Apache helicopter pilots might contribute to facial injury in a crash. The US Army accident database was searched for HDU-related injuries in survivable Apache accidents 1985-1995. Four aviators in three crashes sustained HDU-related injury. These involved three periorbital contusions and two minor eye injuries. There were no sequelae. This equates to an incidence of 0.57 injured individuals per 100,000 flying hours or 8.0 injured aviators per 100 survivable Class A-C accidents in which the HDU was worn. Applying these data to the projected UK Army Apache flying hour programme suggests that one HDU-related injury might be encountered approximately every 10.1 years. This estimate should be interpreted with caution. Serious injury remains a possibility due to the proximity of the HDU to the eye and face.  相似文献   

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