Bioelectric analyses of an osseointegrated intelligent implant design system for amputees.
Bioelectric analyses of an osseointegrated intelligent implant design system for amputees.
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DOI：
10.3791/1237
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发表时间：
2009-07
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通讯作者：
Brad M Isaacson;J. Stinstra;R. Macleod;J. Webster;J. P. Beck;R. Bloebaum
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作者：
Brad M Isaacson;J. Stinstra;R. Macleod;J. Webster;J. P. Beck;R. Bloebaum
预计到2050年，美国截肢者人数将增至360万。这些人中的许多人依赖于假肢来进行日常活动，但是使用传统承窝技术的假肢悬架对于肢体缺失的人来说可能被证明是笨重和不舒服的。此外，对于那些高位近端截肢的患者，有限的残肢长度可能会阻止外假体连接。骨整合种植体技术是一种新型的手术方法，它允许宿主骨和种植体之间牢固的骨骼附着。在欧洲截肢患者中使用骨结合种植体的初步结果表明，通过将载荷直接转移到骨-种植体界面，临床结局得到改善。尽管骨整合相对于接受腔技术具有明显的优势，但目前的康复程序需要长时间的限制性承重，这可以通过电刺激加速骨骼附着来减少。骨整合智能种植体设计（OIID）系统的目标是使种植体成为电气系统的一部分，以加速骨骼附着并帮助预防假体周围感染。为了确定最佳的电极尺寸和位置，我们启动了概念验证，对截肢者残肢的电刺激过程中产生的电场和电流密度进行计算建模。为了确保患者安全，选择了接受回顾性计算机断层扫描的受试者，并使用定制软件程序创建三维重建，以确保IRB和HIPAA批准研究中的解剖准确性（Seg 3D和SCIRun）。这些软件包支持患者特定模型的开发，并允许交互式操纵电极位置和尺寸。初步结果表明，电场和电流密度可以在植入物界面产生，以实现诱导成骨细胞迁移所需的均匀电场分布，增强骨骼固定，并可能有助于预防假体周围感染。基于在模型中实验的电极配置，外部两个带配置将在未来提倡。
The projected number of American amputees is expected to rise to 3.6 million by 2050. Many of these individuals depend on artificial limbs to perform routine activities, but prosthetic suspensions using traditional socket technology can prove to be cumbersome and uncomfortable for a person with limb loss. Moreover, for those with high proximal amputations, limited residual limb length may prevent exoprosthesis attachment all together. Osseointegrated implant technology is a novel operative procedure which allows firm skeletal attachment between the host bone and an implant. Preliminary results in European amputees with osseointegrated implants have shown improved clinical outcomes by allowing direct transfer of loads to the bone-implant interface. Despite the apparent advantages of osseointegration over socket technology, the current rehabilitation procedures require long periods of restrictive load bearing prior which may be reduced with expedited skeletal attachment via electrical stimulation. The goal of the osseointegrated intelligent implant design (OIID) system is to make the implant part of an electrical system to accelerate skeletal attachment and help prevent periprosthetic infection. To determine optimal electrode size and placement, we initiated proof of concept with computational modeling of the electric fields and current densities that arise during electrical stimulation of amputee residual limbs. In order to provide insure patient safety, subjects with retrospective computed tomography scans were selected and three dimensional reconstructions were created using customized software programs to ensure anatomical accuracy (Seg3D and SCIRun) in an IRB and HIPAA approved study. These software packages supported the development of patient specific models and allowed for interactive manipulation of electrode position and size. Preliminary results indicate that electric fields and current densities can be generated at the implant interface to achieve the homogenous electric field distributions required to induce osteoblast migration, enhance skeletal fixation and may help prevent periprosthetic infections. Based on the electrode configurations experimented with in the model, an external two band configuration will be advocated in the future.