Natarajan R N, Andersson G B J, Patwardhan A G, Verma S
Department of Orthopedic Surgery, Rush-Presbyterian-St Luke's Medical Center, Chicago, IL 60612, USA.
J Biomech Eng. 2002 Apr;124(2):229-36. doi: 10.1115/1.1449906.
The technique used to incise the disc during discectomy may play a role in the subsequent healing and change in biomechanical stiffness of the disc. Several techniques of lumbar disc annulotomy have been described in clinical reports. The purpose of this paper was to study the influence of annulotomy technique on motion segment stiffness using a finite element model. Four incision methods (square, circular, cross, and slit) were compared. The analyses showed that each of the annular incisions produced increase in motions under axial moment loadings with circular incision producing the largest change in the corresponding rotational motion. Under shear loading mode, cross and slit-type annular incisions produced slightly larger changes in the principal motions of the disc than square and circular incisions. All other incision types considered in the current study produced negligibly small increase in motion under rest of the loading conditions. In addition to annulotomy, when nucleotomy was also included in the analyses, once again cross and slit incisions produced larger change in motion under shear loading mode as compared to the other two incision types. A comparison between the four types of annular incisions showed that cross incision produced an increase in motion larger than those produced by the other three incisions under flexion/extension and lateral moment loading and both shear force loadings. Circular incision produced the largest increase in motion under axial moment load in comparison to those produced by square, cross, and slit incisions. Sagittal plane symmetry was influenced by the incision injury to the motion segment leading to coupled motions as well as increased facet loads. From the study it can be concluded that the increase inflexibility of the disc due to annulotomy depends on the type of annulotomy and the annulotomy also produce asymmetrical deformations leading to increased facet loading.
椎间盘切除术期间用于切开椎间盘的技术可能在椎间盘随后的愈合以及生物力学刚度变化中发挥作用。临床报告中已描述了几种腰椎间盘环切开术技术。本文的目的是使用有限元模型研究环切开术技术对运动节段刚度的影响。比较了四种切口方法（方形、圆形、十字形和狭缝形）。分析表明，每种环形切口在轴向力矩载荷下均会使运动增加，其中圆形切口在相应旋转运动中产生的变化最大。在剪切载荷模式下，十字形和狭缝形环形切口在椎间盘主要运动中产生的变化略大于方形和圆形切口。在当前研究考虑的所有其他载荷条件下，其余切口类型产生的运动增加可忽略不计。除了环切开术外，当分析中也包括髓核切除术时，与其他两种切口类型相比，十字形和狭缝形切口在剪切载荷模式下再次产生更大的运动变化。四种环形切口之间的比较表明，在屈伸、侧方力矩载荷和两种剪切力载荷下，十字形切口产生的运动增加大于其他三种切口。与方形、十字形和狭缝形切口相比，圆形切口在轴向力矩载荷下产生的运动增加最大。矢状面对称性受运动节段切口损伤的影响，导致耦合运动以及小关节载荷增加。从研究中可以得出结论，环切开术导致的椎间盘僵硬增加取决于环切开术的类型，并且环切开术还会产生不对称变形，导致小关节载荷增加。
