Department of Spine Surgery, Tianjin Hospital, Tianjin University, Jiefangnanlu 406, Hexi District, Tianjin, China.
Southern Medical University, Guangzhou City, Guangdong, China.
BMC Musculoskelet Disord. 2023 Feb 1;24(1):85. doi: 10.1186/s12891-023-06201-7.
To study the biomechanical characteristics of various tissue structures of different sizes of 3D printed Cage in lumbar interbody fusion.
A finite element model of normal spine was reconstructed and verified. Pedicle screws and Cage of different sizes were implanted in the L4/5 segment to simulate lumbar interbody fusion. The range of motion of the fixed and cephalic adjacent segment, the stress of the screw-rod system, the stress at the interface between cage and L5 endplate, and intervertebral disc pressure of the adjacent segment were calculated and analyzed.
The range of motion and intervertebral disc pressure of the adjacent segment of each postoperative model were larger than those of the intact model, but there was not much difference between them. The stress of cage-endplate interface was also larger than that of the intact model. However, the difference is that the stress of the endplate and the screw-rod system has a tendency to decrease with the increase of the axial area of cage.
Cage with larger axial area in lumbar interbody fusion can reduce the stress of internal fixation system and endplate, but will not increase the range of motion and intervertebral disc pressure of adjacent segment. It has a certain effect in preventing the cage subsidence, internal fixation system failure and screw rod fracture.
研究不同尺寸的 3D 打印 Cage 在腰椎椎间融合中各种组织结构的生物力学特性。
重建并验证了正常脊柱的有限元模型。在 L4/5 节段植入不同大小的椎弓根螺钉和 Cage，模拟腰椎椎间融合。计算和分析固定和头侧相邻节段的活动范围、螺钉-棒系统的应力、Cage 与 L5 终板界面的应力以及相邻节段椎间盘的压力。
每个术后模型的相邻节段的活动范围和椎间盘压力均大于完整模型，但差异不大。Cage-终板界面的应力也大于完整模型。然而，不同之处在于，随着 Cage 轴向面积的增加，终板和螺钉-棒系统的应力有减小的趋势。
在腰椎椎间融合中使用较大轴向面积的 Cage 可以降低内固定系统和终板的应力，但不会增加相邻节段的活动范围和椎间盘压力。它在防止 Cage 下沉、内固定系统失效和螺钉断裂方面具有一定的效果。
