PFI:AIR-TT: Self-adaptive growing rod for the treatment of pediatric scoliosis

这个PFI：空气技术翻译项目的重点是翻译一种新型的钛合金，以满足在青少年脊柱侧弯的生长棒治疗过程中改善结果和减少植入相关并发症的需求。适应性生长棒很重要，因为它有可能降低植入物松动和失败的高发生率，这是治疗严重早发性儿童脊柱侧凸的主要并发症来源，通常需要昂贵而痛苦的翻修手术。该项目将产生一个自适应生长杆的工作原型，并在标准化的生物力学模型中证明其可行性。该装置具有与人体骨骼相匹配的同时具有高强度和超低刚度的独特特点，并且能够根据位置改变其刚度。与市场上领先的基于哈林顿棒系统的生长棒相比，这些功能减少了所需的翻修手术数量，减少了主要的并发症来源，更好地分担负荷促进了脊柱的健康发展，并提高了治疗儿童严重脊柱侧弯的整体疗效。该项目在从研究发现转化为商业应用的过程中解决了以下技术空白：目前缺乏对正在生长的杆状结构中骨-螺钉界面的应力如何受种植体硬度影响的定量了解。这一点很重要，因为骨-螺钉界面的高应力被认为是种植体松动和拔出的原因。此外，目前还不知道位置相关的种植体硬度如何改变这种应力。该项目试图通过定量监测钛-Nb合金的微结构工程和热机械训练引入的种植体硬度的变化如何影响骨-螺钉界面的应力来弥合这些差距。实验是使用修正的ASTM标准模型进行的，该模型考虑了不断增长的脊柱的僵硬变化。此外，参与该项目的人员，包括博士研究生和本科生研究人员，将通过直接参与客户开发过程获得创业和技术翻译经验。学生将参加与外科医生、医院管理人员、监管人员和医疗器械制造商的所有对话。学生将被要求独立与客户联系，并接受以NSF i-Corps计划为核心的精益创业战略培训。该项目邀请了儿科整形外科医生和一家医疗器械制造商，以确保对临床需求和挑战以及这项技术从研究发现向商业现实转化的监管和报销障碍有一个清晰和最新的了解。

This PFI:AIR Technology Translation project focuses on translating a novel titanium alloy to address the need for improving the outcome and reducing implant-related complications during growing rod treatment of adolescent scoliosis. The adaptive growing rod is important because of its potential to reduce the high incidence of implant loosening and failure, which are the primary sources of complications in the treatment of severe early-onset scoliosis in children and often necessitate costly and painful revision surgeries. The project will result in a working prototype of an adaptive growing rod and demonstrate its feasibility in a standardized biomechanics model. This device has the unique features of simultaneous high strength and ultra-low stiffness matching that of human bone, and the ability to vary its stiffness depending on location. When compared to the leading competing growing rods based on the Harrington rods system in this market, these features reduce the number of revision procedures required by reducing a leading source of complications, facilitating healthy development of the spine from better load sharing, and improving the overall efficacy for treatment of severe scoliosis in children. This project addresses the following technology gaps as it translates from research discovery toward commercial application: there is a current lack of quantitative understanding of how stress at the bone-screw interface is affected by implant stiffness in growing rod constructs. This is important because high stress at the bone-screw interface is believed to be responsible for implant loosening and pull-outs. Furthermore, it is not known how location-dependent implant stiffness modifies such stress. The project seeks to bridge these gaps by quantitatively monitoring how stress at the bone-screw interface is affected by variations in the implant stiffness introduced by microstructural engineering and thermo-mechanical training in a Ti-Nb alloy. Experiments are performed using a modified ASTM standard model that accounts for the changing stiffness of the growing spine. In addition, personnel involved in this project, including a Ph.D. level graduate student and undergraduate researchers, will receive entrepreneurship and technology translation experiences through direct involvement in the customer development process. Students will participate in all conversations with surgeons, hospital officials, regulatory personnel, and medical devices manufacturers. Students will be asked to make customer contacts independently, and receive training of the lean-startup strategy central to the NSF I-Corps program. The project engages pediatric orthopedic surgeons and a medical devices manufacturer to ensure a clear and current understanding of clinical needs and challenges, as well as regulatory and reimbursement hurdles of this technology translation effort from research discovery toward commercial reality.