Biomechanical Effects of the Geometry of Ball-and-Socket Artificial Disc on Lumbar Spine
Biomechanical Effects of the Geometry of Ball-and-Socket Artificial Disc on Lumbar Spine
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DOI：
10.1097/brs.0000000000001789
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发表时间：
2017-03-15
期刊：
影响因子：
3
通讯作者：
Kim, Sohee
中科院分区：
文献类型：
--
作者：
Choi, Jisoo;Shin, Dong-Ah;Kim, Sohee
研究设计。建立了完整腰椎的三维有限元模型，并对四种不同曲率半径的球窝人工椎间盘植入手术有限元模型进行了比较。采用有限元方法研究球窝人工椎间盘曲率对生物力学的影响。背景资料摘要。全椎间盘置换术（TDR）被认为是治疗退行性椎间盘疾病的一种替代方法，因为它比脊柱融合术更有优势。然而，人工球窝盘曲率的影响尚未完全了解。建立了不同曲率半径的球窝人工椎间盘外科有限元模型。运动范围（ROM）在伸展、屈曲和侧向弯曲中随曲率半径的减小而增大，而在轴向扭转中随曲率半径的增大而增大。关节面接触力在伸展、屈曲和侧弯时曲率半径最大，最小；在轴向扭转时曲率半径最大，接触力最大。椎间盘置入也有影响，后路置入比前路置入更明显。L4松质骨的应力随曲率半径过大或过小而增大。球窝人工椎间盘的几何形状显著影响手术水平的ROM、关节面接触力和松质骨的应力。这意味着在进行TDR时，球窝设计可能不是理想的，因为ROM和关节面接触力对椎间盘设计很敏感，这可能被解剖几何的个体差异夸大。
Study Design. A three-dimensional finite element model of intact lumbar spine was constructed and four surgical finite element models implanted with ball-and-socket artificial discs with four different radii of curvature were compared.Objective. To investigate biomechanical effects of the curvature of ball-and-socket artificial disc using finite element analysis.Summary of Background Data. Total disc replacement (TDR) has been accepted as an alternative treatment because of its advantages over spinal fusion methods in degenerative disc disease. However, the influence of the curvature of artificial ball-and-socket discs has not been fully understood.Methods. Four surgical finite element models with different radii of curvature of ball-and-socket artificial discs were constructed.Results. The range of motion (ROM) increased with decreasing radius of curvature in extension, flexion, and lateral bending, whereas it increased with increasing radius of curvature in axial torsion. The facet contact force was minimum with the largest radius of curvature in extension, flexion, and lateral bending, whereas it was maximum with the largest radius in axial torsion. It was also affected by the disc placement, more with posterior placement than anterior placement. The stress in L4 cancellous bone increased when the radius of curvature was too large or small.Conclusion. The geometry of ball-and-socket artificial disc significantly affects the ROM, facet contact force, and stress in the cancellous bone at the surgical level. The implication is that in performing TDR, the ball-and-socket design may not be ideal, as ROM and facet contact force are sensitive to the disc design, which may be exaggerated by the individual difference of anatomical geometry.