Coronal shear fractures of the femoral neck (CSFF) are the most challenging to treat among proximal femur fractures, directly affecting the life expectancy of patients with osteoporosis. However, an adequate osteosynt...Coronal shear fractures of the femoral neck (CSFF) are the most challenging to treat among proximal femur fractures, directly affecting the life expectancy of patients with osteoporosis. However, an adequate osteosynthesis method has not been elucidated yet. This study investigated the displacement direction of the femoral head fragment and its effect on the bone using finite element method. A finite element model for CSFF was developed from CT image data of a patient with osteoporosis using Mechanical Finder (ver. 11). Subsequently, finite element analyses were performed on six osteosynthesis models under maximum load applied during walking. The compressive stresses, tensile stresses, and compressive strains of each model were examined. The results suggested that the compressive and tensile stress distributions were concentrated on the anterior side of the femoral neck. Compressive strain distribution in the femoral head and neck was concentrated in four areas: at the tip of the blade or lag screw, the anteroinferior side of the blade or lag screw near the fracture site, and the upper right and lower left near the junction of the blade or lag screw and nail. Thus, the distribution of both these stresses revealed that the femoral head fragment was prone to anterior and inferior displacement. Distribution of compressive strains revealed the direction of the stress exerted by the osteosynthetic implant on the bone. The same results were observed in all osteosynthetic implants;thus, the findings could lay the foundation for developing methods for placing osteosynthetic implants less prone to displacement and the osteosynthetic implants themselves. In particular, the study provides insight into the optimal treatment of CSFF.展开更多
A novel reconstructive prosthesis was designed with topological optimization(TO)and a lattice structure to enhance biomechanical and biological properties in the proximal tibia.The biomechanical performance was valida...A novel reconstructive prosthesis was designed with topological optimization(TO)and a lattice structure to enhance biomechanical and biological properties in the proximal tibia.The biomechanical performance was validated through finite element analysis(FEA)and biomechanical tests.The tibia with inhomogeneous material properties was reconstructed according to computed tomography images,and different components were designed to simulate the operation.Minimum compliance TO subject to a volume fraction constraint combined with a graded lattice structure was utilized to redesign the prosthesis.FEA was performed to evaluate the mechanical performances of the tibia and implants after optimization,including stress,micromotion,and strain energy.The results were analyzed by paired-samples t tests,and p<0.05 was considered significant.Biomechanical testing was used to verify the tibial stresses.Compared to the original group(OG),the TO group(TOG)exhibited lower stress on the stem,and the maximum von Mises stresses were 87.2 and 53.1 MPa,respectively,a 39.1%reduction(p<0.05).Conversely,the stress and strain energy on the tibia increased in the TOG.The maximum von Mises stress values were 16.4 MPa in the OG and 22.9 MPa in the TOG with a 39.6%increase(p<0.05),and the maximum SED value was 0.026 MPa in the OG and 0.042 MPa in the TOG,corresponding to an increase of 61.5%(p<0.05).The maximum micromotions in the distal end of the stem were 135μm in the OG and 68μm in the TOG,almost a 50%reduction.The stress curves of the biomechanical test coincided well with the FEA results.The TO approach can effectively reduce the whole weight of the prosthesis and improve the biomechanical environment of the tibia.It could also pave the way for next-generation applications in orthopedics surgery.展开更多
目的探讨骨水泥钉道强化股骨近端防旋髓内钉治疗高龄SeinsheimerⅤ型股骨转子下骨折的可行性。方法选取1名志愿者的CT资料导入Mimics 19.0和Geomagic studio 2017软件中进行提取、优化,得到右侧股骨三维模型;运用Solidworks 2017软件画...目的探讨骨水泥钉道强化股骨近端防旋髓内钉治疗高龄SeinsheimerⅤ型股骨转子下骨折的可行性。方法选取1名志愿者的CT资料导入Mimics 19.0和Geomagic studio 2017软件中进行提取、优化,得到右侧股骨三维模型;运用Solidworks 2017软件画出内固定模型并与股骨模型按照标准手术技术装配,以STEP格式导入Hypermesh14.0软件中截骨得到SeinsheimerⅤ型普通股骨近端防旋髓内钉股骨转子下骨折模型,将螺旋刀片近端周围松质骨重新定义为骨水泥,得到钉道强化股骨近端防旋髓内钉模型。设置材料属性参数、边界条件、施加载荷,分别储存为K文件导入LS-DYNA软件求解。结果(1)与普通PFNA模型相比,钉道强化PFNA模型螺旋刀片基本无切割,头颈骨块的内翻和旋转角度较小,虽然局部应力稍大,但整体更趋稳定;(2)骨水泥强大的锚固力能稳定螺旋刀片,增强三点支撑的内侧作用点,并能传导、分散压力。结论与普通股骨近端防旋髓内钉相比,钉道强化股骨近端防旋髓内钉治疗高龄SeinsheimerⅤ型股骨转子下骨折可以有效减少头颈骨块内翻的旋转,避免螺旋刀片切割,更趋稳定。展开更多
文摘Coronal shear fractures of the femoral neck (CSFF) are the most challenging to treat among proximal femur fractures, directly affecting the life expectancy of patients with osteoporosis. However, an adequate osteosynthesis method has not been elucidated yet. This study investigated the displacement direction of the femoral head fragment and its effect on the bone using finite element method. A finite element model for CSFF was developed from CT image data of a patient with osteoporosis using Mechanical Finder (ver. 11). Subsequently, finite element analyses were performed on six osteosynthesis models under maximum load applied during walking. The compressive stresses, tensile stresses, and compressive strains of each model were examined. The results suggested that the compressive and tensile stress distributions were concentrated on the anterior side of the femoral neck. Compressive strain distribution in the femoral head and neck was concentrated in four areas: at the tip of the blade or lag screw, the anteroinferior side of the blade or lag screw near the fracture site, and the upper right and lower left near the junction of the blade or lag screw and nail. Thus, the distribution of both these stresses revealed that the femoral head fragment was prone to anterior and inferior displacement. Distribution of compressive strains revealed the direction of the stress exerted by the osteosynthetic implant on the bone. The same results were observed in all osteosynthetic implants;thus, the findings could lay the foundation for developing methods for placing osteosynthetic implants less prone to displacement and the osteosynthetic implants themselves. In particular, the study provides insight into the optimal treatment of CSFF.
基金National Natural Science Foundation of China[Grant Numbers 81802174,81900726&82072456]Department of Science and Technology of Jilin Province,P.R.C[Grant Numbers 20200404202YY,20200403086SF&20200201453JC]+8 种基金Jilin Province Development and Reform Commission,P.R.C[Grant Number 2018C010]Education Department of Jilin Province,P.R.C[GrantNumber JJKH20180106KJ]Administration of Traditional Chinese Medicine of Jilin Province P.R.C[Grant Number 2018115]10th Youth Project of the First Hospital of Jilin University[Grant Number JDYY102019025]Department of Finance in Jilin Province[Grant Number 2019SCZT046]Undergraduate Teaching Reform Research Project of Jilin University[Grant Number 4Z2000610852]Key training plan for outstanding young teachers of Jilin University[Grant Number 419080520253]Bethune plan of Jilin University[Grant Number 470110000692]The major participant is Qing Han.
文摘A novel reconstructive prosthesis was designed with topological optimization(TO)and a lattice structure to enhance biomechanical and biological properties in the proximal tibia.The biomechanical performance was validated through finite element analysis(FEA)and biomechanical tests.The tibia with inhomogeneous material properties was reconstructed according to computed tomography images,and different components were designed to simulate the operation.Minimum compliance TO subject to a volume fraction constraint combined with a graded lattice structure was utilized to redesign the prosthesis.FEA was performed to evaluate the mechanical performances of the tibia and implants after optimization,including stress,micromotion,and strain energy.The results were analyzed by paired-samples t tests,and p<0.05 was considered significant.Biomechanical testing was used to verify the tibial stresses.Compared to the original group(OG),the TO group(TOG)exhibited lower stress on the stem,and the maximum von Mises stresses were 87.2 and 53.1 MPa,respectively,a 39.1%reduction(p<0.05).Conversely,the stress and strain energy on the tibia increased in the TOG.The maximum von Mises stress values were 16.4 MPa in the OG and 22.9 MPa in the TOG with a 39.6%increase(p<0.05),and the maximum SED value was 0.026 MPa in the OG and 0.042 MPa in the TOG,corresponding to an increase of 61.5%(p<0.05).The maximum micromotions in the distal end of the stem were 135μm in the OG and 68μm in the TOG,almost a 50%reduction.The stress curves of the biomechanical test coincided well with the FEA results.The TO approach can effectively reduce the whole weight of the prosthesis and improve the biomechanical environment of the tibia.It could also pave the way for next-generation applications in orthopedics surgery.
文摘目的探讨骨水泥钉道强化股骨近端防旋髓内钉治疗高龄SeinsheimerⅤ型股骨转子下骨折的可行性。方法选取1名志愿者的CT资料导入Mimics 19.0和Geomagic studio 2017软件中进行提取、优化,得到右侧股骨三维模型;运用Solidworks 2017软件画出内固定模型并与股骨模型按照标准手术技术装配,以STEP格式导入Hypermesh14.0软件中截骨得到SeinsheimerⅤ型普通股骨近端防旋髓内钉股骨转子下骨折模型,将螺旋刀片近端周围松质骨重新定义为骨水泥,得到钉道强化股骨近端防旋髓内钉模型。设置材料属性参数、边界条件、施加载荷,分别储存为K文件导入LS-DYNA软件求解。结果(1)与普通PFNA模型相比,钉道强化PFNA模型螺旋刀片基本无切割,头颈骨块的内翻和旋转角度较小,虽然局部应力稍大,但整体更趋稳定;(2)骨水泥强大的锚固力能稳定螺旋刀片,增强三点支撑的内侧作用点,并能传导、分散压力。结论与普通股骨近端防旋髓内钉相比,钉道强化股骨近端防旋髓内钉治疗高龄SeinsheimerⅤ型股骨转子下骨折可以有效减少头颈骨块内翻的旋转,避免螺旋刀片切割,更趋稳定。
