SIMULATION OF ELECTRIC STIMULATION FOR BONE GROWTH

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 骨结合是一种在种植体和宿主骨之间提供直接骨骼连接的外科手术。 组织。骨融合已被证明在牙科、耳廓和经股骨设置中取得了成功，然而，持久的 挑战是利用自然的生物生长在种植体和骨之间实现足够的长期固定。受监管 电刺激已被证明在骨折愈合和非创伤骨模型中有效，但还没有。 在经皮骨集成植入系统中进行了研究。截肢患者群体的一个优势是 矫形植入物从残肢突出，不仅起到外固定装置的作用，而且 也可用作外部电刺激装置的电位电极。 因此，这次合作的目标是建立在先前良好证明的临床成功的基础上 诱导骨生长用于促进骨折愈合，并扩展这项技术以加速骨折的骨整合 截肢者的经皮穿透模型。由于骨整合技术对截肢者来说仍然是相当新的技术 在美国尚未临床使用，但提高其效率的方法仍在开发中。加拿大帝国商业银行 由Roy Bloebaum博士指导的合作小组正在通过开发一种骨整合装置来解决这一限制 智能种植设计(OIID)系统已获得美国临时专利， 犹他大学技术商业化办公室作为一种促进骨整合的新型康复工具 技术增加电刺激可以提高初始骨骼的速度、大小和质量 附着在骨整合假体柄上。 为了验证电刺激将增加骨骼附着这一普遍假设，一个分两个阶段的项目 已经设计了利用体外、体内和硅胶方式来证实这项技术的安全性和有效性 在截肢者实施之前。该模型的具体假设建立在组织学评估的基础上， 力学测试和有限元分析。来自Bloebaum小组的研究假设是最 与该中心相关的是《基于有限元的退伍军人残肢有限元仿真分析》 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被 可在骨-植入物界面上实现。 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 目标： 目标1：开发适用于像这样的整形外科应用的分割和网格生成支持 便于快速生成截肢者、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：加速模拟任何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 和参数敏感度。 目标3：制定定位皮肤表面电极的估计和优化策略，使皮肤表面电极最大化 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.