Senior Research Career Scientist

项目摘要/摘要 勒杜博士目前的研究计划旨在通过以下方式减少功能和解剖上的肢体损失： 导致肢体功能异常的疾病过程；量化保守和手术的影响 治疗选择；以及开发研究脚部的新的、最先进的技术。他的研究重点是 在两个退伍军人群体上：那些有脚部和脚踝肌肉骨骼损伤的人，那里的疼痛和 活动受限是关键问题(即功能性肢体丧失)；以及那些有可能因此而截肢的人 到糖尿病，在糖尿病中，失去一只脚是一个主要的问题(即，解剖上的肢体丧失)。他的首要目标是 研究内容包括：(1)深入了解糖尿病足溃疡、足踝和大趾关节炎的发病机制， 和严重的足部畸形；(2)不同足部疾病治疗方案的定量比较 可以改善肢体功能或预防截肢；以及(3)开发新的研究工具。 勒杜博士正在进行几个与拇指强直或第一跖趾关节炎有关的项目。 关节(MTPJ1)。已经提出了各种MTPJ1关节成形术的设计，但没有一种是特别的 成功。旨在解决这些问题的新植入物的开发受到了不足的限制 关于MTPJ1机械环境的定量数据。同样，由于以前的技术限制，没有 关于这种疾病的运动学，都有精确的3D数据可用。攀登从事的是一项新的研究 确定日常生活活动所需的正常MTPJ1功能的运动学包络(RX0032590)。 我们将在最初的成功基础上，产生新的、以证据为基础的植入概念，强调 通过计算建模和机器人步态改善MTPJ1植入技术的初步部件固定 模拟人类身体(R01AR076475)。这些性能更好的植入物最终将导致 病人的结果。我们的工作假设是，一个成功的MTPJ1种植体将表现出强劲的初始状态 部件固定和生理规范的关节生物力学。此外，勒杜博士正在与 与Sangorzan博士进行了一项多部位拇指僵硬研究，比较了运动保留手术(关节置换) 或骨成形)到关节融合术(融合术)。这项研究将确定与治疗成功相关的因素。 开发改进的治疗方案需要对糖尿病疾病有更好的基础了解 病理力学。尽管越来越多的人同意异常压力和剪切力与 溃烂，其具体的致病机制目前尚不清楚。从一个结构 透视-不同材料属性和不同几何形状的组织相互作用以产生体积 回应-大多数研究都是2D的，而且考虑的地点数量有限。考虑到这个复杂的 对于足部的结构和功能运动，应在整个足底表面进行3D研究。 然而，许多负担得起体积查询的技术还有其他顾虑：解剖是破坏性的、有限的 元素模型依赖于假设和简化，CT的软组织分辨率很差，而MRI 在计算上和财政上都很昂贵。超声波具有良好的软组织分辨率，但大多数商业系统 创建平面图像或仅限于较小的角度扫描体积。超声波也很难读懂。 对于天真的用户来说。为了克服这些障碍，我们提出了以下具体目标：1)开发一种机械 系统和必要的软件，使用B超对整个足底软组织进行3D扫描 用于结构信息的超声波和用于组织特性的剪切波弹性成像。2)收集足底柔软 对7名糖尿病非神经病变受试者和7名非糖尿病受试者进行组织扫描。3)使用以下工具分析这些扫描 利用数字体积相关计算的分割和应变信息以及可解释的 分类神经网络。NIH资助的这项先导研究(5U24DK115255-04， 32307-94分奖)将展示拟议方法的实用性，并支持更大规模的赠款申请。

PROJECT SUMMARY/ABSTRACT Dr. Ledoux’s current research program aims to reduce both functional and anatomical limb loss by: exploring the disease processes that lead to aberrant limb function; quantifying the effects of conservative and surgical treatment options; and developing novel, state-of-the-art technologies for studying the foot. His research focuses on two Veteran populations: those with musculoskeletal impairment at the foot and ankle, where pain and limitations in mobility are the key issues (i.e., functional limb loss); and those at risk of lower limb amputation due to diabetes, where loss of the foot is a major concern (i.e., anatomical limb loss). The overarching goals of his research include: (1) insight into the pathomechanics of: diabetic foot ulceration, ankle and great toe arthritis, and severe foot deformities; (2) quantitative comparison of different treatment options for foot pathologies that can lead to improved limb function or prevention of amputation; and (3) the development of novel research tools. Dr. Ledoux is working on several projects related to hallux rigidus, or arthritis of the first metatarsophalangeal joint (MTPJ1). Various designs for MTPJ1 arthroplasties have been proposed, but none have been particularly successful. Development of new implants aimed at addressing these problems has been limited by insufficient quantitative data on the MTPJ1 mechanical environment. Similarly, due to previous technological limitations, no precise 3D data are available on either the kinematics of this disease. CLiMB is engaged in novel research to identify the kinematic envelope of normal MTPJ1 function required during activities of daily living (RX0032590). We will build on our initial successes generating novel, evidence-based implant concepts that emphasize strong initial component fixation to improve MTPJ1 implant technology through computational modeling and robotic gait simulation of human cadavers (R01AR076475). These better-performing implants will ultimately lead to improved patient outcomes. It is our working hypothesis that a successful MTPJ1 implant will exhibit both strong initial component fixation and physiologically normative joint biomechanics. Additionally, Dr. Ledoux is collaborating with Dr. Sangeorzan on a multisite hallux rigidus study comparing motion sparing procedures (joint replacement or bone shaping) to arthrodesis (fusion). This study will determine factors associated with treatment success. Developing improved treatment options requires a better fundamental understanding of diabetic disease pathomechanics. Despite growing agreement that aberrant pressures and shear stresses are linked to ulceration, the specific causative mechanism of ulceration remains poorly understood. From a structural perspective—in which tissues of different material properties and different geometries interact to create a bulk response—most studies have been 2D and limited in the number of locations considered. Given the complex structure and functional motion of the foot, it should be investigated in 3D across the entire plantar surface. However, many techniques that afford volumetric inquiry have other concerns: dissection is disruptive, finite element models rely on assumptions and simplifications, CT has poor soft tissue resolution, and MRI is computationally and fiscally expensive. Ultrasound has good soft tissue resolution, but most commercial systems create planar images or are limited to small, angularly swept volumes. Ultrasound can also be difficult to read for the naïve user. In order to overcome these barriers, we propose these specific aims: 1) Develop a mechanical system and the necessary software to generate a 3D scan of the entire plantar soft tissue, using B-mode ultrasound for structural information and shear wave elastography for tissue properties. 2) Collect plantar soft tissue scans for 7 diabetic non-neuropathic subjects and 7 non-diabetic subjects. 3) Analyze these scans using segmentation and strain information calculated with digital volume correlation as well as an interpretable classification neural network. The successful completion of this NIH funded pilot study (5U24DK115255-04, subaward 32307-94) will demonstrate the utility of the proposed methods and support a larger grant application.