Vasu R, Carter D R, Schurman D J, Beaupré G S
J Biomech. 1986;19(8):647-62. doi: 10.1016/0021-9290(86)90170-3.
Two-dimensional, finite element studies were conducted of the proximal tibia before and after joint arthroplasty. Equivalent-thickness models projected onto the mid-frontal plane were created for the natural, proximal tibia and for the proximal tibia with four different types of tibial plateau components. All components simulated bony ingrowth fixation, i.e. no cement layer existed between component and bone. In addition, the interface between component and bone was assumed to be intimately connected, representing complete bony ingrowth and a rigid state of fixation. Loads consisted of bi-condylar and uni-condylar forces. Results indicated that conventional plateau designs with central posts or multiple pegs led to higher stress magnitudes in the trabecular bone near the distal ends of the post/pegs and stress shielding at more proximal locations. A design without posts or pegs whose interface geometry mimics the epiphyseal plate minimizes bone stress shielding. An implant consisting of separate components covering each condyle was found effective in limiting component tilting and the consequent tensile stresses caused by non-symmetrical, uni-condylar loading.
对关节置换前后的胫骨近端进行了二维有限元研究。针对天然胫骨近端以及带有四种不同类型胫骨平台组件的胫骨近端，创建了投影到中额平面上的等效厚度模型。所有组件均模拟骨长入固定，即组件与骨之间不存在骨水泥层。此外，假定组件与骨之间的界面紧密相连，代表完全骨长入和刚性固定状态。载荷包括双髁和单髁力。结果表明，带有中央柱或多个钉的传统平台设计会导致柱/钉远端附近小梁骨中的应力幅值更高，且在更靠近近端的位置出现应力遮挡。一种没有柱或钉且其界面几何形状模仿骨骺板的设计可使骨应力遮挡最小化。发现由覆盖每个髁的单独组件组成的植入物在限制组件倾斜以及由非对称单髁载荷引起的拉伸应力方面是有效的。
