U.S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Product Evaluation and Quality, Office of Orthopedic Devices, Silver Spring, MD 20993, USA.
U.S. Food and Drug Administration, Center for Devices and Radiological Health, Office of Product Evaluation and Quality, Office of Orthopedic Devices, Silver Spring, MD 20993, USA.
J Biomech. 2021 Aug 26;125:110551. doi: 10.1016/j.jbiomech.2021.110551. Epub 2021 Jun 10.
Thoracolumbosacral pedicle screw systems (TPSSs) are spinal implants commonly utilized to stabilize the spine as an adjunct to fusion for a variety of spinal pathologies. These systems consist of components including pedicle screws, rods, hooks, and various connectors that allow the surgeon to create constructs that can be affixed to a wide range of spinal anatomy. During the development and regulatory clearance process, TPSSs are subjected to mechanical testing such as static and dynamic compression bending per ASTM F1717, axial and torsional grip testing per ASTM F1798, and foam block pullout testing per ASTM F543. In this study, design and mechanical testing data were collected from 200 premarket notification (510(k)) submissions for TPSSs submitted to FDA between 2007 and 2018. Data were aggregated for the most commonly performed mechanical tests, and analyses were conducted to assess differences in performance based on factors such as component type, dimensions, and materials of construction. Rod material had a significant impact on construct stiffness in static compression bending testing with cobalt chromium rods being significantly stiffer than titanium rods of the same diameter. Pedicle screw type had an impact on compression bending yield strength with monoaxial screws having significantly higher yield strength as compared to polyaxial or uniplanar screws. Axial and torsional gripping capacities between components and the rods were significantly lower for cross-connectors than the other component types. The aggregated data presented here can be utilized for comparative purposes to aid in the development of future TPSSs.
胸腰椎椎弓根螺钉系统（TPSS）是一种常用于脊柱的植入物，通常与融合术联合使用，以稳定脊柱，治疗各种脊柱病变。这些系统由椎弓根螺钉、棒、钩和各种连接器组成，允许外科医生构建可以固定在广泛的脊柱解剖结构上的结构。在开发和监管审批过程中，TPSS 要经过机械测试，如静态和动态压缩弯曲测试（根据 ASTM F1717）、轴向和扭转握持测试（根据 ASTM F1798）以及泡沫块拔出测试（根据 ASTM F543）。在这项研究中，收集了 200 份 2007 年至 2018 年提交给 FDA 的用于 TPSS 的上市前通知（510(k)）提交文件中的设计和机械测试数据。对最常进行的机械测试数据进行了汇总，并进行了分析，以评估基于组件类型、尺寸和结构材料等因素的性能差异。在静态压缩弯曲测试中，棒材材料对结构刚度有显著影响，钴铬棒明显比相同直径的钛棒更硬。椎弓根螺钉类型对压缩弯曲屈服强度有影响，单轴螺钉的屈服强度明显高于多轴或单平面螺钉。与其他组件类型相比，交叉连接器的组件和棒之间的轴向和扭转夹持能力明显较低。这里呈现的汇总数据可用于比较目的，以帮助开发未来的 TPSS。
