The objective of this study was to design a novel dynamic fixation system with biodegradable components, apply it for lumbar fusion between articular processes and compare the fusion results and biomechanical changes to those of conventional rigid fixation. The novel dynamic fixation system was designed using a finite element model, stress distributions were compared and 24 mongrel dogs were randomly assigned to two groups and subjected to either posterior lumbar fusion surgery with a novel dynamic fixation system or titanium rods at the L5-L6 segments. Lumbar spines were assessed in both groups to detect radiographic, manual palpation and biomechanical changes. Histological examination was performed on organs and surrounding tissues. In the novel dynamic fixation system, stress was mainly distributed on the meshing teeth of the magnesium alloy spacer. The magnesium alloy components maintained their initial shape 8 weeks after the operation, but the meshing teeth were almost completely degraded at 16 weeks. The novel dynamic fixation system revealed an increased lateral bending range of motion at 8 weeks; however, both groups showed similar radiographic grades, fusion stiffness, manual palpation and histological results. The novel dynamic fixation system design is suitable, and its degradation in vivo is safe. The novel dynamic fixation system can be applied for posterior lumbar fusion between articular processes and complete the fusion like titanium rods.

中文翻译：

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一种新型的动态固定系统，具有可生物降解成分，可用于犬模型中关节突之间的腰椎融合。

这项研究的目的是设计一种具有可生物降解成分的新型动态固定系统，将其应用于关节突之间的腰椎融合，并将融合结果和生物力学变化与常规刚性固定相比较。使用有限元模型设计新型动态固定系统，比较应力分布，将24只杂种犬随机分为两组，并采用新型动态固定系统或L5-L6段钛棒进行后路腰椎融合手术。两组均对腰椎进行了评估，以检测射线照相，手动触诊和生物力学变化。对器官和周围组织进行组织学检查。在新颖的动态注视系统中 应力主要分布在镁合金垫片的啮合齿上。镁合金组件在术后8周保持其初始形状，但在16周时啮合齿几乎完全降解。新颖的动态固定系统揭示了在8周时运动的横向弯曲范围增加了。然而，两组均显示出相似的放射线影像学等级，融合刚度，人工触诊和组织学结果。新颖的动态固定系统设计是合适的，并且其在体内的降解是安全的。该新型动态固定系统可应用于关节突后腰椎融合，并像钛棒一样完成融合。新颖的动态固定系统揭示了在8周时运动的横向弯曲范围增加了。然而，两组均显示出相似的放射线影像学等级，融合刚度，人工触诊和组织学结果。新颖的动态固定系统设计是合适的，并且其在体内的降解是安全的。该新型动态固定系统可应用于关节突后腰椎融合，并像钛棒一样完成融合。新颖的动态固定系统揭示了在8周时运动的横向弯曲范围增加了。然而，两组均显示出相似的放射线影像学等级，融合刚度，人工触诊和组织学结果。新颖的动态固定系统设计是合适的，并且其在体内的降解是安全的。该新型动态固定系统可应用于关节突后腰椎融合，并像钛棒一样完成融合。