International Journal of Precision Engineering and Manufacturing ( IF 1.9 ) Pub Date : 2020-04-24 , DOI: 10.1007/s12541-020-00336-6 Li-Xin Guo , Qing-Dong Wang
Lumbar interbody fusion supplemented with a pedicle screw fixator is an effective treatment for spinal instability, but traditional bilateral pedicle screw fixator may cause some complications, such as degenerative disease of adjacent segments and stress concentration. The purpose of this study is to decrease the stiffness of the rod by using topology optimization to alleviate the above problems. The finite element models of the intact lumbar spine, lumbar spine implanted with traditional bilateral pedicle screw fixator (BPS) and a new fixator designed by using topology optimization (TOD) were developed and compared. Compared with the traditional rigid rod, the volume of TOD rod was reduced by 19.8%. The results showed that the TOD model was similar to the BPS model in terms of the range of motions. TOD reduced intradiscal pressure, stresses in intervertebral discs, and facet contact forces of the adjacent segments. The TOD model significantly decreased the stress concentration region of screws and rods and reduced the stresses in pedicle screws, rods and the junction between the vertebral bodies and screws. TOD fixator may provide a stable condition to the fusion segment as well as the BPS fixator. What’s more, TOD alleviates the adjacent segment disease and lower the risk of screw breakage, rod breakage, and vertebral damage. The new rod designed by topology optimization might also be useful in alleviating adjacent segment disease, stress concentration and stress shielding effect.
中文翻译:
基于拓扑优化的新型双侧椎弓根螺钉固定系统的生物力学分析
腰椎椎间融合器加椎弓根螺钉固定器是治疗脊柱不稳的有效方法,但是传统的双侧椎弓根螺钉固定器可能会引起一些并发症,例如相邻节段的退行性疾病和应力集中。本研究的目的是通过使用拓扑优化来减轻上述问题,从而降低杆的刚度。开发并比较了完整的腰椎,植入传统的双侧椎弓根螺钉固定器(BPS)和采用拓扑优化(TOD)设计的新型固定器的有限元模型。与传统的刚性杆相比,TOD杆的体积减少了19.8%。结果表明,在运动范围方面,TOD模型与BPS模型相似。TOD降低了椎间盘内压力,椎间盘的应力以及相邻节段的小平面接触力。TOD模型显着减小了螺钉和杆的应力集中区域,并降低了椎弓根螺钉,杆和椎体与螺钉之间的连接处的应力。TOD固定器可以为融合节段和BPS固定器提供稳定的状态。此外,TOD可减轻邻近节段疾病的风险,并降低螺丝断裂,杆断裂和椎骨损伤的风险。通过拓扑优化设计的新杆也可能有助于缓解相邻节段疾病,应力集中和应力屏蔽效果。TOD模型显着减小了螺钉和杆的应力集中区域,并降低了椎弓根螺钉,杆和椎体与螺钉之间的连接处的应力。TOD固定器可以为融合节段和BPS固定器提供稳定的状态。此外,TOD可减轻邻近节段疾病的风险,并降低螺丝断裂,杆断裂和椎骨损伤的风险。通过拓扑优化设计的新杆也可能有助于缓解相邻节段疾病,应力集中和应力屏蔽效果。TOD模型显着减小了螺钉和杆的应力集中区域,并降低了椎弓根螺钉,杆和椎体与螺钉之间的连接处的应力。TOD固定器可以为融合节段和BPS固定器提供稳定的状态。此外,TOD可减轻邻近节段疾病的风险,并降低螺丝断裂,杆断裂和椎骨损伤的风险。通过拓扑优化设计的新杆也可能有助于缓解相邻节段疾病,应力集中和应力屏蔽效果。和椎骨损伤。通过拓扑优化设计的新杆也可能有助于缓解相邻节段疾病,应力集中和应力屏蔽效果。和椎骨损伤。通过拓扑优化设计的新杆也可能有助于缓解相邻节段疾病,应力集中和应力屏蔽效果。