UNASSIGNED: To design customized titanium alloy lunate prosthesis, construct three-dimensional finite element model of wrist joint before and after replacement by finite element analysis, and observe the biomechanical changes of wrist joint after replacement, providing biomechanical basis for clinical application of prosthesis.
UNASSIGNED: One fresh frozen human forearm was collected, and the maximum range of motions in flexion, extension, ulnar deviation, and radialis deviation tested by cortex motion capture system were 48.42°, 38.04°, 35.68°, and 26.41°, respectively. The wrist joint data was obtained by CT scan and imported into Mimics21.0 software and Magics21.0 software to construct a wrist joint three-dimensional model and design customized titanium alloy lunate prosthesis. Then Geomagic Studio 2017 software and Solidworks 2017 software were used to construct the three-dimensional finite element models of a normal wrist joint (normal model) and a wrist joint with lunate prosthesis after replacement (replacement model). The stress distribution and deformation of the wrist joint before and after replacement were analyzed for flexion at and 15°, 30°, 48.42°, extension at 15°, 30°, and 38.04°, ulnar deviation at 10°, 20°, and 35.68°, and radial deviation at 5°, 15°, and 26.41° by the ANSYS 17.0 finite element analysis software. And the stress distribution of lunate bone and lunate prosthesis were also observed.
UNASSIGNED: The three-dimensional finite element models of wrist joint before and after replacement were successfully constructed. At different range of motion of flexion, extension, ulnar deviation, and radial deviation, there were some differences in the number of nodes and units in the grid models. In the four directions of flexion, extension, ulnar deviation, and radial deviation, the maximum deformation of wrist joint in normal model and replacement model occurred in the radial side, and the values increased gradually with the increase of the range of motion. The maximum stress of the wrist joint increased gradually with the increase of the range of motion, and at maximum range of motion, the stress was concentrated on the proximal radius, showing an overall trend of moving from the radial wrist to the proximal radius. The maximum stress of normal lunate bone increased gradually with the increase of range of motion in different directions, and the stress position also changed. The maximum stress of lunate prosthesis was concentrated on the ulnar side of the prosthesis, which increased gradually with the increase of the range of motion in flexion, and decreased gradually with the increase of the range of motion in extension, ulnar deviation, and radialis deviation. The stress on prosthesis increased significantly when compared with that on normal lunate bone.
UNASSIGNED: The customized titanium alloy lunate prosthesis does not change the wrist joint load transfer mode, which provided data support for the clinical application of the prosthesis.
UNASSIGNED: 设计定制化钛合金人工月骨假体,利用有限元分析构建假体置换前后腕关节三维有限元模型,观察置换术后腕关节生物力学改变,为假体临床应用提供生物力学依据。.
UNASSIGNED: 取1具新鲜冰冻人前臂标本,经cortex动作捕捉系统测量腕关节掌屈、背伸、尺偏、桡偏最大活动度分别为48.42°、38.04°、35.68°、26.41°。CT扫描获取腕关节数据,首先导入Mimics21.0软件、Magics21.0 软件初步构建腕关节三维模型,设计定制化钛合金人工月骨假体。然后采用Geomagic Studio 2017软件、Solidworks 2017软件构建正常腕关节、月骨假体置换术后腕关节三维有限元模型(正常模型、置换模型)。ANSYS 17.0有限元分析软件中,于腕关节掌屈15°、30°、48.42°,背伸15°、30°、38.04°,尺偏10°、20°、35.68°,桡偏5°、15°、26.41° 分析置换前后腕关节应力分布及形变,以及月骨及月骨假体的应力分布情况。.
UNASSIGNED: 研究成功构建假体置换前后腕关节三维有限元模型。掌屈、背伸、尺偏、桡偏方向不同活动度腕关节模型的网格划分节点及网格数存在一定差异。在掌屈、背伸、尺偏、桡偏方向,正常模型及置换模型腕关节最大形变均发生于桡侧,且均随活动度增大而逐渐增大;腕关节最大应力亦随活动度增大而逐渐增大,在最大活动度下应力均集中于桡骨近端,整体表现为由桡侧腕骨向桡骨近端移动的趋势。在不同方向上正常月骨最大应力均表现为随活动度增大而逐渐增大趋势,且应力位置发生对应改变。而月骨假体最大应力均集中在假体尺侧,背伸时随活动度增大逐渐增大,掌屈、尺偏、桡偏时则整体表现为随活动度增大而逐渐减小。术后月骨假体所受应力较正常月骨明显增大。.
UNASSIGNED: 有限元分析提示采用定制化钛合金人工月骨假体置换不会改变腕关节载荷传递模式,为假体临床应用提供数据支持。.