SIMULATION OF ELECTRIC STIMULATION FOR BONE GROWTH

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 骨整合是一种在种植体和宿主骨之间提供直接骨骼附着的外科手术 组织. 骨整合已被证明在牙科、耳廓和经股动脉设置中是成功的，然而， 挑战是利用自然生物生长在植入物和骨之间实现足够的长期固定。 调节 电刺激已被证明在骨折愈合和非创伤性骨模型中有效，但尚未被 在经皮骨整合种植体系统中进行研究。截肢患者群体的一个优势是 整形外科植入物从残肢突出，不仅用作外假体附件， 也用作外部电刺激装置的电位电极。 因此，此次合作的目标是建立在以前的，经过充分证明的，临床成功的电 诱导骨生长，用于增强骨折愈合，并扩展该技术，以加速骨整合， 截肢者的经皮模型。 由于骨整合技术对于下肢截肢者来说仍然是相当新的 并且在美国没有临床应用，提高其效率的方法仍在开发中。 CIBC 由Roy Bloebaum博士领导的一个合作小组正在通过开发骨整合 智能植入物设计（OIID）系统已获得美国临时专利， 犹他州大学技术商业化办公室作为改善骨整合的新型康复工具 技术.电刺激的添加可以增加初始骨骼肌再生的速率、幅度和质量。 与骨整合假体柄的连接。 为了验证电刺激会增加骨骼附着的一般假设，一个两阶段的项目已经 设计为利用体外、体内和计算机模拟模式来确认该技术的安全性和有效性 在截肢者中实施之前。 该模型的具体假设基于组织学评估， 机械测试和有限元分析。 Bloebaum小组的研究假设是最重要的， 与该中心相关的是，“退伍军人和战士截肢者残肢的有限元仿真分析 用计算机断层扫描成像将揭示，安全有效的电流密度和电场将 可在骨-植入物界面处获得。" 为了通过创建必要的模拟基础设施来评估这一假设，该中心拥有以下技术 目的： 目标1：开发适合骨科应用（如本例）的分割和网格生成支持， 为了便于快速生成截肢者以及植入物和刺激电极的精确几何模型 这些建模应用程序所需的。 目标2：加速模拟任意选定边界的电场和电流密度所需的计算 植入物和皮肤表面电极的条件，并提供结果的广泛可视化，包括确定性 参数敏感性。 目标3：制定估计和优化策略，以最大限度地提高皮肤表面电极的定位效率。 电刺激骨整合的生长潜力。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Osseointegration is a surgical procedure that provides direct skeletal attachment between an implant and host bone tissue. Osseointegration has proven success in dental, auricle, and transfemoral settings, however, a persistent challenge is achieving adequate long term fixation between implant and bone using natural biological growth. Regulated electrical stimulation has proven effective in fracture healing and non-traumatized bone models, but has not been investigated in a percutaneous osseointegrated implant system. One advantage of the amputee patient population is that an orthopedic implant protrudes from the residual limb functioning not only as an exoprosthesis attachment but also as a potential electrode for an external electrical stimulation device. Therefore, the objective of this collaboration is to build upon the previous, well proven, clinical success of electrically induced bone growth used to augment fracture healing and expand this technology to accelerate osseointegration in the percutaneous model for amputees. Since osseointegration technology is still fairly new for lower extremity amputees and not utilized clinically in the United States, approaches to increasing its efficiency are still developing. The CIBC collaborator group, directed by Dr. Roy Bloebaum, is addressing this limitation by developing an Osseointegrated Intelligent Implant Design (OIID) system which has been awarded a United States provisional patent with the University of Utah Technology Commercialization Office as a novel rehabilitation tool to improve osseointegration technology. The addition of electrical stimulation may increase the rate, magnitude, and quality of initial skeletal attachment to the osseointegrated prosthetic stem. To validate the general hypothesis that electrical stimulation will increase skeletal attachment, a two phase project has been designed that utilizes in vitro, in vivo, and in silico modalities to confirm the safety and efficacy of this technology prior to implementation in amputees. The specific hypotheses for this model are founded on histological assessment, mechanical testing, and finite element analysis. The research hypothesis from the Bloebaum group that is most relevant to the Center is that, "Finite element based simulation analysis of veteran and warrior amputee residual limbs imaged with computed tomography scans will reveal that safe and effective current densities and electric fields will be attainable at the bone-implant interface." To evaluate this hypothesis by creating the necessary simulation infrastructure, the Center has the following technical aims: Aim 1: Develop segmentation and mesh generation support that is adapted to orthopedic applications like this one and to facilitate the rapid generation of accurate geometric models of amputees and the implants and stimulation electrodes required for these modeling applications. Aim 2: Accelerate the computations required to simulate electric fields and current densities for any selected boundary conditions of implant and skin surface electrodes and provide extensive visualization of the results that include certainty and parameter sensitivity. Aim 3: Develop estimation and optimization strategies for locating skin surface electrodes in ways that maximize the growth potential for electrical stimulation of osseointegration.