中国组织工程研究

中国组织工程研究 ›› 2021, Vol. 25 ›› Issue (18): 2799-2804.doi: 10.3969/j.issn.2095-4344.3840

• 骨与关节生物力学 bone and joint biomechanics • 上一篇    下一篇

皮质骨轨迹螺钉固定对相邻节段影响的有限元分析

魏源标1，2，3，郭惠智3，张顺聪4   

  1. 1广州中医药大学，广州中医药大学同等学力申请硕士学位人员，广东省广州市    510405；2广东药科大学附属第一医院正骨科，广东省广州市  510080；3广州中医药大学第一临床医学院，广东省广州市   510405；4广州中医药大学第一附属医院脊柱科，广东省广州市   510405
  • 收稿日期:2020-08-18 修回日期:2020-08-21 接受日期:2020-09-15 出版日期:2021-06-28 发布日期:2020-01-11
  • 通讯作者: 张顺聪，主任医师，广州中医药大学第一附属医院脊柱骨科，广东省广州市 510405
  • 作者简介:魏源标，男，1987年生，广东省廉江市人，广州中医药大学在读硕士。
  • 基金资助:
    广州中医药大学第一附属医院创新强院项目(2019ⅡT32)，项目负责人：张顺聪

Finite element analysis of cortical bone trajectory screw fixation on adjacent segments

Wei Yuanbiao1, 2, 3, Guo Huizhi3, Zhang Shuncong4   

  1. 1Personnel Applying for Master's Degree with the Same Educational Background in Guangzhou University of Chinese Medicine, Guangdong Province, China; 2Department of Bone Orthopedics, First Affiliated Hospital, Guangdong Pharmaceutical University, Guangdong Province, China; 3First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangdong Province, China; 4Department of Spine, First Affiliated 

  • Received:2020-08-18 Revised:2020-08-21 Accepted:2020-09-15 Online:2021-06-28 Published:2020-01-11
  • Contact: Zhang Shuncong, Chief physician, Department of Spine, First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510405, Guangdong Province, China
  • About author:Wei Yuanbiao, Master candidate, Personnel Applying for Master's Degree with the Same Educational Background in Guangzhou University of Chinese Medicine, Guangzhou 510405, Guangdong Province, China; Department of Bone Orthopedics, First Affiliated Hospital, Guangdong Pharmaceutical University, Guangzhou 510080, Guangdong Province, China; First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou 510405, Guangdong Province, China
  • Supported by:
    the Innovation and Strengthening Project of the First Affiliated Hospital of Guangzhou University of Chinese Medicine, No. 2019IIT32 (to ZSC)

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摘要：

文题释义：
皮质骨轨迹螺钉：是一种新型的椎体固定技术，通过使螺钉的轨迹尽可能的与椎体后部及椎弓根的坚硬皮质骨接触，从而达到提高螺钉把持力、稳定椎体的目的，目前已成功应用在脊柱退变性疾病和脊柱骨折等疾病中。
相邻节段退变：是指固定节段的上下端发生的退变，其发病机制尚不明确，一般认为与手术内固定和患者术前的退变程度等因素有关。相比于尸体研究，有限元分析可以直观准确地观察相邻节段活动度、椎间盘应力和小关节应力等指标。因此，该研究通过有限元模拟的方式，评估皮质骨轨迹螺钉固定对邻近节段的影响。

背景：皮质骨轨迹螺钉是近年来兴起的新型脊柱内固定方式，可明显增加内固定的抗拔出力，取得和传统椎弓根螺钉相似或更优的生物力学稳定性，但其对相邻节段的影响尚不清楚。
目的：比较皮质骨轨迹螺钉固定与椎弓根螺钉固定对相邻节段椎间盘和小关节的影响。 
方法：通过一位正常男性志愿者的腰椎CT扫描数据，建立L3至骶骨的腰骶椎有限元模型。验证完整模型的有效性后，建立L4-5节段的皮质骨轨迹螺钉固定与椎弓根螺钉固定模型，设置模型的材料属性，比较两种内固定方式对上下相邻节段(L3-4和L5-S1节段)椎间活动度、椎间盘应力和小关节应力的影响。
结果与结论：①有限元验证结果显示模型可较好地模拟正常腰椎的生理活动；②在上下相邻节段活动度和椎间盘Von Mises应力上，两种固定方式在各个活动方向上差异较小(<10%)；在相邻节段小关节Von Mises应力上，皮质骨轨迹螺钉固定模型在各工况下L4上关节突的应力均小于椎弓根螺钉固定模型，尤其是在左旋和右旋时明显，分别减小了30.1%和15.9%；但在尾端相邻小关节应力上，皮质骨轨迹螺钉固定模型L5下关节突的最大等效应力在前屈、后伸、左侧弯和左旋时较椎弓根螺钉固定模型分别增加10.4%，20%，9.6%和2.7%，在右侧弯和右旋时减小24.5%和7.4%；③总的来说，两种固定方式对相邻节段活动度和椎间盘应力的影响相似，但相比于椎弓根螺钉固定，皮质骨轨迹螺钉固定减小了头端相邻小关节的应力，增加了尾端相邻小关节的应力。
https://orcid.org/0000-0002-6212-9913 (张顺聪)

中国组织工程研究杂志出版内容重点：人工关节；骨植入物；脊柱；骨折；内固定；数字化骨科；组织工程

关键词: 皮质骨轨迹螺钉, 椎弓根螺钉, 相邻节段退变, 内固定, 脊柱, 有限元分析

Abstract: BACKGROUND: In recent years, cortical bone trajectory screws have been used as a new type of spinal internal fixation; it can significantly increase the pull-out strength in lumbar vertebra and achieve similar biomechanical stability to traditional trajectory pedicle screw. However, the influence of cortical bone trajectory screws on adjacent segments has not been evaluated. 
OBJECTIVE: To compare the influence of cortical bone trajectory screws and traditional trajectory pedicle screw on adjacent intervertebral disc and facet joint. 
METHODS: An intact finite element model of L3 to sacrum was constructed by using CT scan data of normal male volunteers. After verifying the validity of the intact lumbosacral model, the traditional trajectory pedicle screw and cortical bone trajectory screws models of L4-5 level segment fixation were reconstructed, respectively. The material properties of the models were set up. The influences of the two internal fixation instruments on the motion range of adjacent segments, disc stress and facet joint of the upper and lower adjacent segments (L3-4 and L5-S1) were compared.
RESULTS AND CONCLUSION: (1) The finite element validity showed that the model could simulate the physiological activities of normal lumbar spine well. (2) The difference of the two fixation models in adjacent segments was small (<10%) in motion range and the Von Mises stress of the intervertebral disc. As for the Von Mises stress of adjacent facet joints, the stress at L4 superior articular process in cortical bone trajectory screws model was less than that of traditional trajectory pedicle screw model in all working conditions, especially in left and right rotations (reduced by 30.1% and 15.9%, respectively). The maximum equivalent stress of at L5 inferior articular process in the cortical bone trajectory screws model increased by 10.4%, 20%, 9.6% and 2.7% compared with the traditional trajectory pedicle screw model in flexion, extension, left bending and left rotation, respectively, and decreased by 24.5% and 7.4% in right bending and right rotation, respectively. (3) Overall, the influences of the two instruments on the motion range and disc stress of adjacent segments were similar, but compared with traditional trajectory pedicle screw fixation, cortical bone trajectory screws reduced the stress of cephalic adjacent facet and increased the stress of caudal adjacent facet joints.

Key words: cortical bone trajectory screws, pedicle screw, adjacent segment degeneration, internal fixation, spine, finite element analysis

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