Alcántara-Arreola Elliot Alonso, Silva-Garcés Karla Nayeli, Mendoza-Martínez Jocabed, Cardoso-Palomares Miguel Antonio, Torres-SanMiguel Christopher René
Instituto Politécnico Nacional, Escuela Superior de Ingeniería Mecánica y Eléctrica, Unidad Zacatenco, Sección de Estudios de Posgrado e Investigación, Ciudad de México 07738, Mexico.
J Funct Biomater. 2024 Aug 22;15(8):238. doi: 10.3390/jfb15080238.
Bone cortical tissues reorganize and remodel in response to tensile forces acting on them, while compressive forces cause atrophy. However, implants support most of the payload. Bones do not regenerate, and stress shielding occurs. The aim is to analyze the biomechanical behavior of a lumbar cage to study the implant's stress shielding. The ASTM E-9 standard was used with the necessary adjustments to perform compression tests on lumbar and thoracic porcine spinal vertebrae. Twelve cases were analyzed: six with the metal prosthesis and six with the PEEK implant. A mathematical model based on the Hertz contact theory is proposed to assess the stress shielding for endoprosthesis used in spine pathologies. The lumbar spacer (screw) helps to reduce the stress shielding effect due to the ACME thread. The best interspinous spacer is the PEEK screw. It does not embed in bone. The deformation capability increases by 11.5% and supports 78.6 kg more than a system without any interspinous spacer.
骨皮质组织会因作用于其上的拉力而重新组织和重塑，而压力则会导致萎缩。然而，植入物承担了大部分负荷。骨骼不会再生，会出现应力遮挡。目的是分析腰椎椎间融合器的生物力学行为，以研究植入物的应力遮挡情况。采用了经过必要调整的ASTM E - 9标准，对猪的腰椎和胸椎椎体进行压缩试验。分析了12个案例：6个使用金属假体，6个使用聚醚醚酮（PEEK）植入物。提出了一种基于赫兹接触理论的数学模型，以评估用于脊柱疾病的内置假体的应力遮挡情况。腰椎椎间融合器（螺钉）由于采用了梯形螺纹，有助于降低应力遮挡效应。最佳的棘突间融合器是PEEK螺钉。它不会嵌入骨中。与没有任何棘突间融合器的系统相比，其变形能力提高了11.5%，支撑能力增加了78.6千克。
