College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, China.
Department of Spine Surgery, Weifang People's Hospital, Weifang, China.
Comput Methods Biomech Biomed Engin. 2024 Aug;27(11):1448-1459. doi: 10.1080/10255842.2023.2245517. Epub 2023 Aug 31.
Problems, such as broken screws, broken rods, and cage subsidence after clinical spinal fusion surgery affect the success rate of fusion surgery and the fixation effect of fusion segments, and these problems still affect the treatment and postoperative recovery of patients. In this study, we used the biomechanical finite element analysis method to analyze and study the fixation effect of three kinds of spinal internal fixation systems on L4-L5 lumbar spine segments in percutaneous endoscopic posterior lumbar interbody fusion (PE-PLIF). The three different fixation systems compared in this study include bilateral pedicle screw fixation (M1); bilateral pedicle screw with cross-link fixation (M2); bilateral pedicle screws with double bent rods fixation (M3). The internal fixation systems with different structures were analyzed with the help of Hypermesh, and Abaqus. It was found that the internal fixation system with double bent rods reduced screw stresses by 23.8 and 22.2% in right and left axial rotation than the traditional bilateral pedicle screw system, while titanium rod stresses were reduced by 9.6, 3.7, 9.6, and 2.9% in flexion, left and right lateral bending, and right axial rotation, respectively, and L5 upper endplate stresses were reduced by 35.5, 18.9, 38.4, 10.2, and 48.3% in flexion, left and right lateral bending, and left and right axial rotation, respectively. The spinal range of motion (ROM) of the M3 internal fixation system was less than that of the M1 and M2 internal fixation systems in left lateral bending, left lateral rotation, and right axial rotation, and the intact vertebral ROM was reduced by 93.7, 94.9, and 90.9%, respectively. The double bent rod structure of the spinal internal fixation system has better biomechanical properties, which can effectively reduce the risk of screw breakage, loosening, cage subsidence, and endplate collapse after fusion surgery.
问题，如螺钉断裂、棒材断裂以及 cage 下沉，会影响脊柱融合手术的成功率和融合节段的固定效果，这些问题仍会影响患者的治疗和术后恢复。在这项研究中，我们使用生物力学有限元分析方法，分析和研究了三种不同的脊柱内固定系统在经皮内镜后路腰椎椎间融合术（PE-PLIF）中对 L4-L5 腰椎节段的固定效果。本研究比较的三种不同的固定系统包括双侧椎弓根螺钉固定（M1）；双侧椎弓根螺钉交叉固定（M2）；双侧椎弓根螺钉双弯棒固定（M3）。通过 Hypermesh 和 Abaqus 等软件对不同结构的内固定系统进行了分析。结果发现，与传统的双侧椎弓根螺钉系统相比，双弯棒内固定系统使右侧和左侧轴向旋转时螺钉的应力分别降低了 23.8%和 22.2%，而钛棒的应力在屈伸、左右侧屈和右侧轴向旋转时分别降低了 9.6%、3.7%、9.6%和 2.9%，L5 上终板的应力在屈伸、左右侧屈和左右轴向旋转时分别降低了 35.5%、18.9%、38.4%、10.2%和 48.3%。M3 内固定系统的脊柱活动度（ROM）在左侧侧屈、左侧旋转和右侧轴向旋转时均小于 M1 和 M2 内固定系统，完整椎体的 ROM 分别减少了 93.7%、94.9%和 90.9%。脊柱内固定系统的双弯棒结构具有更好的生物力学性能，可有效降低融合术后螺钉断裂、松动、cage 下沉和终板塌陷的风险。
