目的探讨闭合复位经皮空心螺钉内固定治疗隐匿型Lisfranc损伤的临床效果。方法北京市顺义区医院于2017年1月至2022年1月收治隐匿型Lisfranc损伤患者35例,男22例、女13例,所有患者均采用C型臂透视下闭合复位、复位钳加压。采用美国足踝...目的探讨闭合复位经皮空心螺钉内固定治疗隐匿型Lisfranc损伤的临床效果。方法北京市顺义区医院于2017年1月至2022年1月收治隐匿型Lisfranc损伤患者35例,男22例、女13例,所有患者均采用C型臂透视下闭合复位、复位钳加压。采用美国足踝外科协会(American Orthopaedic Foot and Ankle Society,AOFAS)中足评分、患者简明健康量表(the MOS item short from health survey,SF-36)评分和视觉模拟评分法(visual analogue scale,VAS)评分评估临床效果,随访观察临床结果和并发症发生情况。结果术后所有患者的切口均一期愈合,无感染和皮肤坏死等切口并发症,无血管和神经损伤。随访时间3~36个月,平均(22.5±4.8)个月;骨折愈合时间8~12周,平均(6.5±0.3)周。末次随访AOFAS中足评分为(80.1±6.1)分,VAS评分为(2.2±0.3)分,SF-36的生理评分为(81.4±6.7)分,SF-36的躯体疼痛评分为(84.5±7.6)分。末次随访时,3例出现空心螺钉松动,均无症状,未出现断钉现象;2例出现轻度关节退变,无症状,未做处理。足部功能根据AOFAS评分标准评定:优22例,良7例,可6例,优良率为82.86%。结论闭合复位经皮空心螺钉内固定治疗隐匿型Lisfranc损伤的效果显著。展开更多
The material characteristics of a structure will change with temperature variation,and will induce stress within the structure.Currently,the optimal design for the topology of compliant mechanisms is mainly performed ...The material characteristics of a structure will change with temperature variation,and will induce stress within the structure.Currently,the optimal design for the topology of compliant mechanisms is mainly performed in single physical field.However,when compliant mechanisms work in high temperature environments,their displacement outputs are generated not only by mechanical load,but also by the temperature variation which may become the prominent factor.Therefore,the influence of temperature must be considered in the design.In this paper,a novel optimization method for multi-objective topology of thermo-mechanical compliant mechanisms is presented.First,the thermal field is analyzed with finite-element method,where the thermal strain is taken into account in the constitutive relation,and the equivalent nodal thermal load is derived with the principle of virtual work.Then the thermal load is converted into physical loads in elastic field,and the control equation of the thermo-mechanical compliant mechanism is obtained.Second,the mathematical model of the multi-objective topology optimization is built by incorporating both the flexibility and stiffness.Meanwhile,the coupling sensitivity function and the sensitivity analysis equations of thermal steady-state response are derived.Finally,optimality criteria algorithm is employed to obtain numerical solution of the multi-objective topology optimization.Numerical examples show that the compliant mechanisms have better performance and are more applicable if the temperature effect is taken into account in the design process.The presented modeling and analysis methods provide a new idea and an effective approach to topology optimization of compliant mechanisms in electrothermic coupling field and multiphysics fields.展开更多
文摘目的探讨闭合复位经皮空心螺钉内固定治疗隐匿型Lisfranc损伤的临床效果。方法北京市顺义区医院于2017年1月至2022年1月收治隐匿型Lisfranc损伤患者35例,男22例、女13例,所有患者均采用C型臂透视下闭合复位、复位钳加压。采用美国足踝外科协会(American Orthopaedic Foot and Ankle Society,AOFAS)中足评分、患者简明健康量表(the MOS item short from health survey,SF-36)评分和视觉模拟评分法(visual analogue scale,VAS)评分评估临床效果,随访观察临床结果和并发症发生情况。结果术后所有患者的切口均一期愈合,无感染和皮肤坏死等切口并发症,无血管和神经损伤。随访时间3~36个月,平均(22.5±4.8)个月;骨折愈合时间8~12周,平均(6.5±0.3)周。末次随访AOFAS中足评分为(80.1±6.1)分,VAS评分为(2.2±0.3)分,SF-36的生理评分为(81.4±6.7)分,SF-36的躯体疼痛评分为(84.5±7.6)分。末次随访时,3例出现空心螺钉松动,均无症状,未出现断钉现象;2例出现轻度关节退变,无症状,未做处理。足部功能根据AOFAS评分标准评定:优22例,良7例,可6例,优良率为82.86%。结论闭合复位经皮空心螺钉内固定治疗隐匿型Lisfranc损伤的效果显著。
基金supported by National Science Foundation for Distinguished Young Scholars of China (Grant No. 50825504)United Fund of National Natural Science Foundation of China and Guangdong Province (Grant No. U0934004)+1 种基金National Hi-tech Research and Development Program of National China (863 Program, Grant No. 2009AA04Z204)Fundamental Research Funds for the Central Universities (Grant No. D2102380)
文摘The material characteristics of a structure will change with temperature variation,and will induce stress within the structure.Currently,the optimal design for the topology of compliant mechanisms is mainly performed in single physical field.However,when compliant mechanisms work in high temperature environments,their displacement outputs are generated not only by mechanical load,but also by the temperature variation which may become the prominent factor.Therefore,the influence of temperature must be considered in the design.In this paper,a novel optimization method for multi-objective topology of thermo-mechanical compliant mechanisms is presented.First,the thermal field is analyzed with finite-element method,where the thermal strain is taken into account in the constitutive relation,and the equivalent nodal thermal load is derived with the principle of virtual work.Then the thermal load is converted into physical loads in elastic field,and the control equation of the thermo-mechanical compliant mechanism is obtained.Second,the mathematical model of the multi-objective topology optimization is built by incorporating both the flexibility and stiffness.Meanwhile,the coupling sensitivity function and the sensitivity analysis equations of thermal steady-state response are derived.Finally,optimality criteria algorithm is employed to obtain numerical solution of the multi-objective topology optimization.Numerical examples show that the compliant mechanisms have better performance and are more applicable if the temperature effect is taken into account in the design process.The presented modeling and analysis methods provide a new idea and an effective approach to topology optimization of compliant mechanisms in electrothermic coupling field and multiphysics fields.
