Department of Orthopaedics, Jinling Hospital of Nanjing Medical University, 305 Zhongshan East Road, Nanjing, 210000, Jiangsu Province, China.
Faculty of Engineering and the Environment, University of Southampton, Southampton, UK.
BMC Musculoskelet Disord. 2023 Apr 14;24(1):298. doi: 10.1186/s12891-023-06380-3.
To evaluate the biomechanical effects of different miniplates on restorative laminoplasty.
Assembled restorative laminoplasty models were developed based on 3D printed L4 lamina. Based on different internal fixations, the research was divided into H-shaped miniplates (HSMs) group, two-hole miniplates (THMs) group, and L-shaped miniplates (LSMs) group. The static and dynamic compression tests were analyzed to investigate the biomechanical effects of different internal fixations in restorative laminoplasty, until the failure and fracture of miniplates, or the collapse of miniplates. The static compression tests adopted the speed control mode, and the dynamic fatigue compression tests adopted the load control mode.
The "door close" and the collapse of lamina occurred in THMs group and LSMs group, and plate break occurred in LSMs group. However, these phenomenon was absent in HSMs group, and only plate crack around a screw and looseness of a screw tail cap were found in HSMs group. The sustainable yield load of HSMs group was greater than that of THMs group and LSMs group (P < 0.05). No significant difference in yielding-displacement was found between HSMs group and LSMs group (P > 0.05), while both were much less than that of THMs (P < 0.05). Moreover, the compressive stiffness and the axial displacement under the same mechanical load were arranged as follows: HSMs group > LSMs group > THMs group (P < 0.05). The results of dynamic compression test revealed that the peak load of HSMs group could reached 873 N and was 95% of the average yield load of the static compression, and was better than that in THMs group and LSMs group (P < 0.05). Besides, according to the fatigue life-peak load diagram, the ultimate load of HSMs group was more than twice that of THMs group or LSMs group.
The mechanical strength of H-shaped miniplates was superior to two-hole miniplates and L-shaped miniplates in maintaining spinal canal enlargement and spinal stability, and was more excellent in fatigue stability and ultimate load.
评估不同微型钢板对修复性椎板成形术的生物力学影响。
根据 3D 打印的 L4 椎板，建立修复性椎板成形术模型。根据不同的内固定方式，研究分为 H 形微型钢板（HSMs）组、双孔微型钢板（THMs）组和 L 形微型钢板（LSMs）组。分析静态和动态压缩试验，研究不同内固定方式在修复性椎板成形术中的生物力学影响，直至微型钢板失效和断裂，或微型钢板塌陷。静态压缩试验采用速度控制模式，动态疲劳压缩试验采用载荷控制模式。
THMs 组和 LSMs 组发生“关门”和椎板塌陷，LSMs 组发生微型钢板断裂，而 HSMs 组未见上述现象，仅发现 HSMs 组螺钉周围出现裂纹和螺钉尾帽松动。HSMs 组的可持续屈服载荷大于 THMs 组和 LSMs 组（P<0.05）。HSMs 组和 LSMs 组的屈服位移无显著差异（P>0.05），均明显小于 THMs 组（P<0.05）。此外，相同机械载荷下的压缩刚度和轴向位移的排列顺序如下：HSMs 组>LSMs 组>THMs 组（P<0.05）。动态压缩试验结果表明，HSMs 组的峰值载荷可达 873 N，为静态压缩平均屈服载荷的 95%，优于 THMs 组和 LSMs 组（P<0.05）。此外，根据疲劳寿命-峰值载荷图，HSMs 组的极限载荷是 THMs 组或 LSMs 组的两倍多。
H 形微型钢板在维持椎管扩大和脊柱稳定性方面的力学强度优于双孔微型钢板和 L 形微型钢板，在疲劳稳定性和极限载荷方面更具优势。
