Sohn Seil, Park Tae Hyun, Chung Chun Kee, Kim Yongjung Jay, Jang Jong Wuk, Han In-Bo, Lee Sung Jae
Department of Neurosurgery, CHA University, CHA Bundang Medical Center, Republic of Korea.
R&D Center, Medyssey Co, Ltd, Jechon, Republic of Korea; Department of Biomedical Engineering, College of Biomedical Science & Engineering, Inje University, Gyeongnam, Republic of Korea.
J Clin Neurosci. 2018 Jun;52:109-114. doi: 10.1016/j.jocn.2018.03.002. Epub 2018 Mar 23.
We aim to characterize the biomechanical properties of a modified iliac screw fixation method compared with the classic iliac screw fixation and the S2 alar iliac screw (S2AI) fixation using a FEM. A three-dimensional, non-linear FEM of lumbosacral spine and pelvis (L1-pelvis) was modified to simulate 3 different iliac screw fixations based on posterior screw fusion. The peak von Mises stress (PVMS) values of the iliac screws in the 3 different iliac screw fixations were recorded in during flexion/extension/axial rotation/lateral bending. The interaction stress which arose between the screw head and the shaft of iliac screws, was also measured for each case. The PVMS values of the 3 different iliac screw fixation techniques were lower than the fatigue strength levels under physiological loadings. PVMS of iliac screws was observed in the screw shaft for S2AI, in the screw neck for the modified iliac screw technique, and in the offset connectors of the classic iliac screw technique. The interaction between the screw head and the neck was compressed in modified iliac screw fixation technique. On the other hand, distraction force was observed in the S2AI technique between the screw head and the screw shaft. This FEM study supports our previous clinical results, which found that the modified iliac screw fixation technique can be an effective alternative sacropelvic fixation technique comparable to the classic iliac screw and the S2AI technique.
我们旨在通过有限元模型（FEM），比较改良髂骨螺钉固定方法与经典髂骨螺钉固定及S2翼髂螺钉（S2AI）固定的生物力学特性。对腰骶椎和骨盆（L1-骨盆）的三维非线性有限元模型进行改良，以基于后路螺钉融合模拟3种不同的髂骨螺钉固定。在屈伸、轴向旋转和侧方弯曲过程中，记录3种不同髂骨螺钉固定中髂骨螺钉的峰值米塞斯应力（PVMS）值。还测量了每种情况下髂骨螺钉螺钉头与螺钉杆之间产生的相互作用应力。3种不同髂骨螺钉固定技术的PVMS值均低于生理负荷下的疲劳强度水平。S2AI的髂骨螺钉PVMS出现在螺钉杆，改良髂骨螺钉技术出现在螺钉颈部，经典髂骨螺钉技术出现在偏置连接器处。改良髂骨螺钉固定技术中螺钉头与螺钉颈部之间的相互作用受到压缩。另一方面，在S2AI技术中，观察到螺钉头与螺钉杆之间存在牵张力。这项有限元模型研究支持了我们之前的临床结果，即改良髂骨螺钉固定技术可以成为一种有效的替代骶骨盆固定技术，可与经典髂骨螺钉和S2AI技术相媲美。
