Identification of New Biomarkers for Determining Risk of Lower Extremity Fracture during Exoskeleton-assisted Ambulation: Developing a Personal Rehabilitation Approach to Optimize Function after SCI

患有急性脊髓损伤的人有快速和进行性的皮下骨质丢失，在节段骨丢失高达73%。 骨痂在受伤后的头几年内吸收，使其处于脆性骨折和后遗症的高风险中。 骨折并发症。据估计，70-76%的脊髓损伤(SCI)患者将持续低... 在他们的一生中发生冲击性或病理性骨折。超过80%的脆性骨折发生在下肢， 最常见的骨折部位是膝部(例如，股骨远端和胫骨近端)。病理性的 骨折和骨折后并发症会导致患者的发病率和巨大的费用。 机器人外骨骼将成为脊髓损伤患者日常活动的可行选择。该部门 退伍军人事务部已经承诺为每一位符合条件的SCI退伍军人提供外骨骼 想要一个，私人保险公司包括机器人外骨骼用于治疗只是时间问题 步行作为标准护理的一个组成部分，可能会加速这类设备的普遍普及。这个 可能会提出的问题是，什么是准确预测骨折风险的最佳临床方法 脊髓损伤患者在开外骨骼辅助行走(EAW)设备之前？虽然数量很大 在身体成分、新陈代谢、心理和整体生活质量方面的改善被观察到 使用EAW时，外骨骼将本已脆弱的脊髓损伤人群置于更大的骨折风险中。骨折 EAW期间脊髓损伤已有报道，发病率从7.1%到10.0%不等。因此，它是 似乎可以推测，如果外骨骼的临床处方采用不那么严格的标准 当设备的使用变得更广泛时，骨折的发生率就会更高。有能力 预测哪些脊髓损伤患者在EAW期间骨折的风险最高，将允许适当和先发制人 最大限度地减少骨折发生和最大限度地提高参与者资格的方法。在先前工作的基础上， 拟议的研究将为EAW处方的循证阈值提供科学依据 退伍军人。拟议的研究将开发新的循证生物标志物，以识别脊髓损伤患者。 当参加直立康复活动时，长骨和/或跟骨骨折的风险最高。这个 能够预测哪些SCI患者在EAW期间骨折的风险最高，这将使循证 减少骨折和相关发病率的方法，以及防止可避免的医疗成本。 这项工作的目的是：(1)确定脊髓损伤患者骨健康的生物标志物。 从髋部、膝盖和跟骨的各种骨密度建立特定的有限元(FE)模型；(2) 测定外骨骼辅助坐位时脊髓损伤患者的髋关节、膝关节和踝关节的作用力 站立和站立；(3)测定脊髓损伤患者的髋关节、膝关节和踝关节的受力。 在EAW期间。我们与ReWalk Robotics、Parker Hannifin和Ekso Bionics的合作伙伴关系将提供 调查人员可以访问专有的电机扭矩数据，使我们能够建立准确的肌肉骨骼模型 人类与机器人的互动。将招募45名患有脊髓损伤的参与者和10名健全的(AB)对照组 用于双X射线吸收测量术(DXA)、外周定量计算机断层扫描(PQCT)和 将在詹姆斯·J·彼得斯退伍军人事务医疗中心(JJP VAMC)进行断层扫描(CT)。 这些设备的培训将在JJP VAMC进行。计算模型和基于有限元的生物标志物 将开发，外骨骼动作的运动捕捉分析将在新的 泽西理工学院。而在三个外骨骼设备(ReWalk、Ekso和Indego)中的每一个中， 髋关节、膝关节和踝关节的力将在坐姿到坐姿过程中结合运动分析进行量化。 站立动作(19个SCI和7个AB对照组)和EAW期间(10个SCI和4个AB对照组)。特定主题 将开发具有髋关节、膝关节和脚踝关节力的有限元模型，以量化机械应力/应变 EAW，与以FE为基础的生物标志物相关。应该获得对人与机器人交互的新见解。

Persons with acute SCI have rapid and progressive sublesional bone loss, with up to 73% bone at the epiphyses resorbed within the first few years after injury, placing them at high risk of fragility fractures and post- fracture complications. It is estimated that 70-76% of persons with spinal cord injury (SCI) will sustain a low- impact, or pathologic, fracture during their lifetime. Over 80% of fragility fractures occur in the lower extremities, with the most common fracture site being the knee region (e.g., distal femur and proximal tibia). Pathological fractures and post-fracture complications lead to patient morbidity and substantial cost. Robotic exoskeletons will become a viable option for routine mobility for people with SCI. The Department of Veterans Affairs has already committed to providing an exoskeleton to every eligible Veteran with SCI who wants one, and it is only a matter of time before private insurance companies include robotic exoskeletons for ambulation as a component of standard care, likely accelerating the general popularity of such devices. The question that may be raised is what is the optimal clinical approach to accurately predict the risk of fracture in persons with SCI prior to prescribing an exoskeletal-assisted walking (EAW) device? Although substantial improvements in body composition, metabolism, psychology, and overall quality of life have been observed with EAW use, exoskeletons place an already vulnerable SCI population at an even greater risk of fracture. Fractures in persons with SCI during EAW have been reported, with incidence ranging from 7.1% to 10.0%. Thus, it is plausible to speculate that if less stringent criteria are employed for the clinical prescription of exoskeleton devices when their use becomes more widespread that the incidence of fracture will be higher. The ability to predict which persons with SCI are at highest risk for fracture during EAW will allow appropriate and preemptive approaches to minimize the occurrence of fractures and to maximize participant eligibility. Building on prior work, the proposed study will provide a scientific rationale for evidence-based thresholds for prescribing EAW in Veterans. The proposed study will develop new evidence-based biomarkers to identify persons with SCI at highest risk of long-bone and/or calcaneus fractures when participating in upright rehabilitation activities. The ability to predict which persons with SCI are at highest risk for fracture during EAW will allow evidence-based approaches to minimize fractures and associated morbidity, as well as prevent avoidable medical costs. The Aims of this work are: (1) to determine biomarkers of bone health in persons with SCI from subject- specific finite element (FE) models from a wide range of bone densities at the hip, knee, and calcaneus; (2) to determine the forces at the hip, knee, and ankle joints of persons with SCI during exoskeleton-assisted sit-to- stand and stand-to-sit; and (3) to determine the forces at the hip, knee, and ankle joints of persons with SCI during EAW. Our partnerships with ReWalk Robotics, Parker Hannifin, and Ekso Bionics will provide the investigators with access to proprietary motor torque data, enabling us to build accurate musculoskeletal models of human-robot interaction. Forty-five (45) participants with SCI and 10 able-bodied (AB) controls will be recruited for dual x-ray absorptiometry (DXA), peripheral quantitative computed tomography (pQCT), and computed tomography (CT) that will be performed at the James J. Peters Veterans Affairs Medical Center (JJP VAMC). Training in the devices will be performed at the JJP VAMC. The computational models and FE-based biomarkers will be developed, and the motion capture analyses of exoskeletal maneuvers, will be performed at the New Jersey Institute of Technology. While in the each of the three exoskeletal devices (ReWalk, Ekso, and Indego), the forces at the hip, knee, and ankle joints will be quantified in conjunction with motion analysis during sit-to- stand maneuvers (in 19 SCI and 7 AB controls) and during EAW (In 10 SCI and 4 AB controls). Subject-specific FE models with hip, knee, and ankle joint forces will be developed to quantify mechanical stress/strain during EAW and correlated to FE-based biomarkers. Novel insights into human-robot interaction should be obtained.