FE stress analysis of the interface between the bone and an osseointegrated implant for amputees - Implications to refine the rehabilitation program
FE stress analysis of the interface between the bone and an osseointegrated implant for amputees - Implications to refine the rehabilitation program
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DOI：
10.1016/j.clinbiomech.2008.06.012
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发表时间：
2008-12-01
影响因子：
1.8
通讯作者：
Frossard, Laurent A.
中科院分区：
文献类型：
--
作者：
Lee, Winson C. C.;Doocey, Jacinta M.;Frossard, Laurent A.
背景下肢假肢的直接锚固到骨已被证明是一个很好的替代截肢者遇到并发症，在使用传统的假肢接受腔。在康复阶段，要求截肢者在基台上垂直于体重秤施加静态载荷，以使骨骼能够承受行走过程中可能产生的力。体重秤只测量垂直力。不同的加载方案可以影响骨-种植体界面应力和修复效果。本研究开发了一个有限元模型，以研究种植体附近骨中的应力。根据实验测得的载荷施加三种载荷条件：（1）沿肢体长轴沿着施加垂直力，对应于负重运动中临床规定的载荷;（2）施加在三个轴上的载荷，对应于在同一运动期间由三轴载荷传感器同时测量的“真实”载荷;和（3）独立行走过程中所经历的负荷。该模型显示，体重秤实际上可能对骨骼施加比预期更高且更不均匀的应力。在行走过程中，高应力发生在植入区域的各个位置，这与负重运动期间的应力分布模式不同。三种载荷条件下的应力差异表明，在负重练习期间应监测三轴载荷并仔细规定。(C)2008爱思唯尔有限公司保留所有权利。
Background. The direct anchorage of lower-limb prosthesis to the bone has been shown to be an excellent alternative for amputees experiencing complications in using a conventional prosthetic socket. During rehabilitation phase, amputees are asked to apply static loading on the abutment perpendicular to a weigh scale to prepare the bone to tolerate the forces likely to be developed during walking. The weigh scale measures only the vertical force. A different loading protocol can affect the bone-implant interface stresses and the outcome of the rehabilitation.Methods. This study developed a Finite Element model to study the stresses in the bone adjacent to the implant. Three loading conditions were applied based on the experimentally measured load: (1) vertical force applied along the long axis of the limb, corresponding to the load clinically prescribed in the weight bearing exercise; (2) loads applied on the three axes, corresponding to the "true" load measured simultaneously by a tri-axial load transducer during the same exercise; and (3) loads experienced during independent walking.Findings. The model revealed that the weigh scale might in fact be applying much higher and less uniform stresses on the bone than expected. During walking, high stress occurred at various locations of the implanted region, which was different from the patterns of stress distribution during weight bearing exercises.Interpretations. The difference in stress among three loading conditions implies that tri-axial load should be monitored during the weight bearing exercises and carefully prescribed. (C) 2008 Elsevier Ltd. All rights reserved.