上颈椎不稳三维动力学模型的建立及有限元分析。

PubMed ID
G H
发表日期 2019年Jun月

原始出处 骨科手术
Orthopaedic surgery
作者 Wang  Xiao-Dong  Feng  Min-Shan  Hu  Yong-Cheng 

文献标题 上颈椎不稳三维动力学模型的建立及有限元分析。
Establishment and Finite Element Analysis of a Three-dimensional Dynamic Model of Upper Cervical Spine Instability.
Establishment and Finite Element Analysis of a Three-dimensional Dynamic Model of Upper Cervical Spine Instability.

文献摘要 OBJECTIVES

建立上颈椎不稳的三维动态模型,分析其生物力学特性。

METHODS

对上颈椎标本进行CT扫描,建立三维几何模型。疲劳标本韧带,建立上颈椎不稳模型。在枕骨上表面施加100N的预加载应力,然后在枕矢状方向施加1.5nm的力矩来模拟上颈椎的屈曲和伸展。随后,基于运动捕捉系统测量的轨迹数据建立了三维动力学模型。分析了主韧带应力和关节相对运动角。

RESULTS

模型网格形状规则,单元总数为627000个。通过有限元分析,得到了韧带应力和相对运动角的结果。上颈椎失稳后,上颈椎伸展过程中翼韧带的压力由2.85增加到8.12 MPa。上颈椎屈曲时黄韧带压力增加,从0.90~1.21mpa。上颈椎屈伸过程中齿状韧带压力降低,分别为10.46~6.67 MPa和25.66~16.35 MPa。在上颈椎屈伸过程中,前纵韧带和交叉韧带的压力均有一定程度的增加。前纵韧带在屈伸过程中压力增加,分别为7.70~10.10mpa和10.45~13.75mpa。屈伸过程中交叉韧带压力增加,分别为2.29~4.34mpa和2.32~4.40mpa。此外,上颈椎失稳后,寰枕关节和寰枢关节的关节面相对运动角也发生了变化。上颈椎屈曲时,寰枕关节角度由3.49°增加到5.51°,寰枢关节角度由8.84°增加到13.70°。上颈椎伸展时,寰枕关节角度由11.16°增加到12.96°,寰枢关节角度由14.20°增加到17.20°。因此,寰枢椎关节失稳后的运动角度最为明显。

CONCLUSION

上颈椎三维动态有限元模型可用于分析和总结颈椎不稳时韧带应力变化与失稳程度的关系。频繁或长时间的屈曲活动更容易导致上颈椎不稳。


OBJECTIVES

To establish a dynamic three-dimensional (3D) model of upper cervical spine instability and to analyze its biomechanical characteristics.

METHODS

A 3D geometrical model was established after CT scanning of the upper cervical spine specimen. The ligament of the specimen was fatigued to establish the upper cervical spine-instability model. A 100-N preloaded stress was applied to the upper surface of the occipital bone, and then a 1.5-Nm moment was applied in the occipital-sagittal direction to simulate upper cervical spine flexion and extension. Subsequently, the 3D dynamic model was established based on trajectory data that were measured using a motion-capture system. The stress on the main ligament and the relative motion angle of the joint were analyzed.

RESULTS

The shape of the model grid was regular and the total number of its units was 627 000. After finite-element analysis was conducted, results of the ligament stress and relative movement angle were obtained. After the upper cervical spine instability, the pressure of the alar ligament during the upper cervical spine extension was increased from 2.85 to 8.12 MPa. The pressure of the flavum ligament was increased during the upper-cervical spine flexion, from 0.90 to 1.21 MPa. The pressure of the odontoid ligament was reduced during the upper cervical spine flexion and extension, from 10.46 to 6.67 MPa and 25.66 to 16.35 MPa, respectively. The pressure of the anterior longitudinal ligament and cruciate ligament was increased to a certain degree during upper cervical spine flexion and extension. The pressure of the anterior longitudinal ligament was increased during flexion and extension, from 7.70 to 10.10 MPa and 10.45 to 13.75 MPa, respectively. The pressure of the cruciate ligament was increased during flexion and extension, from 2.29 to 4.34 MPa and 2.32 to 4.40 MPa, respectively. In addition, after upper cervical spine instability, the articular-surface relative-movement angle of the atlanto-occipital joint and atlanto-axial joint had also changed. During upper cervical spine flexion, the angle of the atlanto-occipital joint was increased from 3.49° to 5.51°, and the angle of the atlanto-axial joint was increased from 8.84° to 13.70°. During upper cervical spine extension, the angle of the atlanto-occipital joint was increased from 11.16° to 12.96°, and the angle of the atlanto-axial joint was increased from 14.20° to 17.20°. Therefore, the movement angle of the atlanto-axial joint was most obvious after induction of instability.

CONCLUSION

The 3D dynamic finite-element model of the upper cervical spine can be used to analyze and summarize the relationship between the change of ligament stress and the degree of instability in cervical instability. Frequent or prolonged flexion activities are more likely to lead to instability of the upper cervical spine.

OBJECTIVES

To establish a dynamic three-dimensional (3D) model of upper cervical spine instability and to analyze its biomechanical characteristics.

METHODS

A 3D geometrical model was established after CT scanning of the upper cervical spine specimen. The ligament of the specimen was fatigued to establish the upper cervical spine-instability model. A 100-N preloaded stress was applied to the upper surface of the occipital bone, and then a 1.5-Nm moment was applied in the occipital-sagittal direction to simulate upper cervical spine flexion and extension. Subsequently, the 3D dynamic model was established based on trajectory data that were measured using a motion-capture system. The stress on the main ligament and the relative motion angle of the joint were analyzed.

RESULTS

The shape of the model grid was regular and the total number of its units was 627 000. After finite-element analysis was conducted, results of the ligament stress and relative movement angle were obtained. After the upper cervical spine instability, the pressure of the alar ligament during the upper cervical spine extension was increased from 2.85 to 8.12 MPa. The pressure of the flavum ligament was increased during the upper-cervical spine flexion, from 0.90 to 1.21 MPa. The pressure of the odontoid ligament was reduced during the upper cervical spine flexion and extension, from 10.46 to 6.67 MPa and 25.66 to 16.35 MPa, respectively. The pressure of the anterior longitudinal ligament and cruciate ligament was increased to a certain degree during upper cervical spine flexion and extension. The pressure of the anterior longitudinal ligament was increased during flexion and extension, from 7.70 to 10.10 MPa and 10.45 to 13.75 MPa, respectively. The pressure of the cruciate ligament was increased during flexion and extension, from 2.29 to 4.34 MPa and 2.32 to 4.40 MPa, respectively. In addition, after upper cervical spine instability, the articular-surface relative-movement angle of the atlanto-occipital joint and atlanto-axial joint had also changed. During upper cervical spine flexion, the angle of the atlanto-occipital joint was increased from 3.49° to 5.51°, and the angle of the atlanto-axial joint was increased from 8.84° to 13.70°. During upper cervical spine extension, the angle of the atlanto-occipital joint was increased from 11.16° to 12.96°, and the angle of the atlanto-axial joint was increased from 14.20° to 17.20°. Therefore, the movement angle of the atlanto-axial joint was most obvious after induction of instability.

CONCLUSION

The 3D dynamic finite-element model of the upper cervical spine can be used to analyze and summarize the relationship between the change of ligament stress and the degree of instability in cervical instability. Frequent or prolonged flexion activities are more likely to lead to instability of the upper cervical spine.


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