Dynamic Bone-Implant Loading in Osseointegrated Prostheses

项目摘要 骨整合假体是一种新型的替代假体承窝直接安装假体 通过骨锚定植入物传递到残肢，这改善了地面之间的载荷传递 和残肢骨-种植体界面的适当载荷对长期结果至关重要， 可导致植入物松动，过载可导致假体周围骨折。初步结局证据 对于假体骨整合后的功能和生活质量的改善非常有希望 然而，由于植入物松动或断裂导致的机械失效持续存在， 这一人群的一小部分，这可能对患者产生严重的负面影响。 尽管骨-植入物载荷对结果有直接影响，但无法在体内测量。因此，在本发明中， 有限元模型是用于估计骨-植入物载荷的最广泛使用的替代物。然而，这些先前 模型有三个主要的限制，阻碍了它们的临床应用：1）它们没有包括日常活动， 活的，2）他们没有纳入肌肉力量，和3）他们还没有发展为经胫骨 骨整合假体。该提案的第一个目标是利用现有的数据集， 开发一个最先进的建模平台，将量化患者的骨-植入物界面载荷 在日常生活中使用经股骨和经胫骨骨整合假体。 假体骨整合后的康复涉及机械负荷的进展， 逐渐增加负重和强化练习，旨在促进骨重建， 骨和植入物以承受日常生活所需的负荷。在康复阶段，步态再训练是 规定重新训练患者的运动模式，因为他们习惯于直接加载的新能力。 残留的骨头尽管康复对于优化患者结果至关重要，但由于缺乏 经验数据导致方案定义不明确，缺乏验证，且不适用于截肢 水平本提案的第二个目标是确定模拟康复对骨的影响- 经胫骨和经胫骨骨整合假体患者的种植体界面载荷。 这一建议将是第一个量化动态骨-种植体界面负荷在骨整合 假体，同时结合受试者特定的运动，肌肉和关节力（目标1），并评估 康复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， 假体骨整合后的康复对于优化该人群的结果至关重要。作为 假体骨整合的认识增加，关于其对肌肉骨骼系统影响的证据是 迫切需要使这种有前途的假体更容易为更广泛的人群所用。

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.