Department of Orthopaedics, Beijing Friendship Hospital, Capital Medical University, Xicheng District, Beijing, 101100, China.
Department of Spine Surgery, Affiliated Hospital of Chengde Medical University, Chengde, 067000, Hebei, China.
BMC Musculoskelet Disord. 2022 Jun 17;23(1):585. doi: 10.1186/s12891-022-05543-y.
Lumbar spinal stenosis (LSS) is a common disease among elderly individuals, and surgery is an effective treatment. The development of minimally invasive surgical techniques, such as the lumbar interspinous process device (IPD), has provided patients with more surgical options.
To investigate the biomechanical properties of different IPDs, including BacFuse, X-Stop and Coflex, in the treatment of LSS.
Based on the computed tomography images of a patient with LSS, four finite element (FE) models of L3-S5 were created in this study. The FE models included a surgical model of the intact lumbar spine and surgical models of the lumbar IPDs BacFuse, X-Stop, and Coflex. After validating the models, they were simulated for four physiological motions: flexion, extension, lateral bending and axial rotation, and range of motion (ROM). Stress distribution of discs and facet joints in each segment, stress distribution of the spinous process in the operated section, and stress distribution of the internal fixation were compared and analysed.
Compared to the model of the intact lumbar spine, the other three models showed a decrease in ROM and disc and facet joint stresses in the surgical segment during movement and an increase in ROM and disc and facet joint stresses in the adjacent segments. These effects were greater for the proximal adjacent segment with BacFuse and more pronounced for the distal adjacent segment with Coflex, while X-Stop had the greatest stress effect on the spinous process in the surgical segment.
BacFuse, Coflex and X-Stop could all be implemented to effectively reduce extension and disc and facet joint stresses, but they also increase the ROM and disc and facet joint stresses in adjacent segments, which may cause degeneration.
腰椎管狭窄症（LSS）是老年人的常见病，手术是一种有效的治疗方法。微创外科技术的发展，如腰椎棘突间装置（IPD），为患者提供了更多的手术选择。
研究不同的 IPD（BacFuse、X-Stop 和 Coflex）在治疗 LSS 中的生物力学特性。
基于一位 LSS 患者的 CT 图像，本研究建立了 L3-S5 的四个有限元（FE）模型。FE 模型包括完整腰椎的手术模型和腰椎 IPD 的手术模型 BacFuse、X-Stop 和 Coflex。在验证模型后，对其进行了四个生理运动（前屈、伸展、侧屈和轴向旋转）和运动范围（ROM）的模拟。比较和分析了每个节段椎间盘和小关节的应力分布、手术节段棘突的应力分布以及内固定的应力分布。
与完整腰椎模型相比，其他三个模型在运动过程中手术节段的 ROM 和椎间盘及小关节的应力减小，而相邻节段的 ROM 和椎间盘及小关节的应力增加。BacFuse 对近端相邻节段的影响更大，Coflex 对远端相邻节段的影响更明显，而 X-Stop 对手术节段棘突的应力影响最大。
BacFuse、Coflex 和 X-Stop 都可以有效地减少伸展和椎间盘及小关节的应力，但也会增加相邻节段的 ROM 和椎间盘及小关节的应力，这可能导致退化。
