Dynamic Bone-Implant Loading in Osseointegrated Prostheses

项目总结 骨集成假体是直接安装假体的假体插座的一种新的替代方案 通过骨锚固植入物转移到残肢，从而改善了地面之间的载荷传递 和残肢。当负荷不足时，在骨-种植体界面的适当负荷对长期结果至关重要。 可导致假体松动和超载，可导致假体周围骨折。初步结果证据 对于假体骨整合后功能和生活质量的改善是非常有希望的 与传统的插座相比；然而，由于种植体松动或断裂而导致的机械故障在 这一人群中的一小部分，可能会对患者产生毁灭性的负面影响。 虽然植入物的负荷对结果有直接影响，但不能在体内测量。结果, 有限元模型是估计骨-种植体载荷的最广泛使用的替代物。然而，这些先前的 模型有三个主要的局限性，阻碍了它们的临床应用：1)它们没有包括日常活动 活着，2)它们没有结合肌肉力量，3)它们不是为经胫骨而发展的 骨整合假体。此建议的第一个目标是利用现有数据集 开发一种最先进的建模平台，将量化患者的骨-种植体界面载荷 在日常生活活动中使用经股骨和经胫骨的骨整合假体。 假体骨整合后的康复包括机械负荷通过 逐步增加负重和加强练习，旨在促进骨改建准备 维持日常生活所需负荷的骨骼和植入物。在进一步的康复阶段，步态再训练 处方，以重新训练患者的运动模式，因为他们习惯了新的能力，直接加载 残留的骨头。尽管康复是优化患者预后的关键，但它仍然受到缺乏 导致协议定义不明确、缺乏有效性且不特定于截肢的经验数据 水平。这项提议的第二个目标将是建立模拟康复对骨骼的影响- 经胫骨和经胫骨整合型假体患者的种植体界面负荷。 这项建议将首次量化骨整合中的动态骨-种植体界面负荷 假体，同时结合特定对象的运动、肌肉和关节力量(目标1)，并评估 康复训练对这些负荷模式的影响(目标2)。因为机械故障主要是由于 骨-种植体界面的病理负荷，了解截肢水平，活动度， 假体骨结合后的康复对于优化这一人群的预后至关重要。AS 假体骨整合意识的提高，关于其对肌肉骨骼系统影响的证据是 迫切需要使这一有希望的假体更容易为更广泛的人群所接受。

PROJECT SUMMARY An osseointegrated prosthesis is a novel alternative to a prosthesis socket that directly mounts the prosthesis to the residual limb through a bone anchored implant, which improves the load transmission between the ground and residual limb. Proper loading at the bone-implant interface is critical to long-term outcome as underloading can lead to implant loosening and overloading can lead to periprosthetic fracture. Preliminary outcome evidence is highly promising regarding improvements in function and quality of life following prosthesis osseointegration compared to a traditional socket; however, mechanical failure due to implant loosening or fracture persists in a small subset of this population, which can have devastatingly negative impacts on the patient. Although bone-implant loading has a direct impact on outcome, it cannot be measured in-vivo. As a result, finite element models are the most widely used surrogate to estimate bone-implant loading. However, these prior models have three primarily limitations that impede their clinical utility: 1) they have not included activities of daily living, 2) they have not incorporated muscle forces, and 3) they have not been developed for transtibial osseointegrated prostheses. The first goal of this proposal is to leverage an existing dataset that will develop a state-of-the-art modeling platform that will quantify bone-implant interface loading in patients with transfemoral and transtibial osseointegrated prostheses during activities of daily living. Rehabilitation following prosthesis osseointegration involves progression of mechanical loading through gradual increase in weight bearing and strengthening exercises designed to promote bone remodeling to prepare the bone and implant to sustain loads required for daily living. Further on in the healing stage, gait retraining is prescribed to retrain the movement patterns of the patient as they habituate to the new ability to directly load the residual bone. Although rehabilitation is pivotal to optimize patient outcome, it remains hindered by a lack of empirical data that results in protocols being not well defined, lacking validation, and not specific to amputation level. The second goal of this proposal will be to establish the effects of simulated rehabilitation on bone- implant interface loading in patients with transtibial and transtibial osseointegrated prostheses. This proposal will be the first to quantify dynamic bone-implant interface loading in osseointegrated prostheses while incorporating subject-specific movement, muscle, and joint forces (Aim 1) and to assess the effects of rehabilitation on these loading patterns (Aim 2). Because mechanical failures are largely due to pathologic loading at the bone-implant interface, understanding how it is altered by amputation level, activity, and rehabilitation following prosthesis osseointegration is critical to optimizing outcomes in this population. As prosthesis osseointegration gains in awareness, evidence regarding its effect on the musculoskeletal system is critically needed to make this promising prosthesis more accessible to a broader population.