Department of Traditional Chinese Medicine, Medical School, Jinan University, Guangzhou, China.
J Surg Res. 2013 Jun 1;182(1):62-7. doi: 10.1016/j.jss.2012.09.012. Epub 2012 Sep 28.
Microdiscectomy is a common surgical procedure used to treat lumbar disc herniation. Following microdiscectomy, the space of the excised nucleus pulposus is replaced by fibrocartilaginous granulation tissue. This results in alterations of both the material properties of the intervertebral disc and the biomechanics of the lumbar motion segments, potentially contributing to adjacent segmental disc degeneration. To our knowledge, there is no published study in the English literature investigating this potential effect.
A previously developed three-dimensional finite element model of L3-L5 was used as a normal control. From this normal model, two different grades of disc degeneration models (mild and moderate) and corresponding microdiscectomy models were developed by changing either the geometry or associated material properties of L4-L5 segment. The 800 N pre-compressive loading plus 10 Nm moments simulating flexion, extension, lateral bending, and axial rotation were imposed on L3 superior end plate of each model. The intradiscal pressure, intersegmental rotation, and tresca stress of annulus fibrosus in L3-L4 segment were investigated.
The intradiscal pressure, intersegmental rotation, and tresca stress of L3-L4 segment in mild degeneration microdiscectomy model are higher than those in the mild degeneration model under all motion directions. The above parameters in moderate degeneration microdiscectomy model present a similar trend to the mild degeneration microdiscectomy model. However, the intersegmental rotation of L3-L4 in moderate degeneration microdiscectomy model is lower than that in the moderate degeneration model in lateral bending, and the intradiscal pressure of L3-L4 in moderate degeneration microdiscectomy model is lower than that in the moderate degeneration model in axial rotation.
Lumbar microdiscectomy can result in altered biomechanics, which may have an adverse effect on the development of adjacent upper segmental disc degeneration.
经皮内镜腰椎间盘切除术是一种治疗腰椎间盘突出症的常见手术方法。经皮内镜腰椎间盘切除术后，切除的髓核空间被纤维软骨肉芽组织取代。这导致椎间盘的材料特性和腰椎运动节段的生物力学都发生了改变，可能导致相邻节段椎间盘退变。据我们所知，目前还没有发表在英文文献中的研究探讨这种潜在的影响。
我们使用先前开发的 L3-L5 三维有限元模型作为正常对照。从这个正常模型中，通过改变 L4-L5 节段的几何形状或相关材料特性，我们构建了两种不同程度的椎间盘退变模型（轻度和中度）和相应的经皮内镜腰椎间盘切除术模型。在每个模型的 L3 上终板上施加 800N 的预压缩载荷和 10N·m 的弯矩，模拟屈伸、侧屈和轴向旋转。研究了 L3-L4 节段椎间盘内压、节段间旋转和纤维环 Tresca 应力。
在轻度退变经皮内镜腰椎间盘切除术模型中，L3-L4 节段的椎间盘内压、节段间旋转和纤维环 Tresca 应力在所有运动方向上均高于轻度退变模型。中度退变经皮内镜腰椎间盘切除术模型的上述参数呈现出与轻度退变经皮内镜腰椎间盘切除术模型相似的趋势。然而，在侧屈运动中，中度退变经皮内镜腰椎间盘切除术模型的 L3-L4 节段间旋转较小，在轴向旋转中，中度退变经皮内镜腰椎间盘切除术模型的 L3-L4 椎间盘内压较小。
腰椎经皮内镜腰椎间盘切除术可导致生物力学改变，这可能对相邻上位节段椎间盘退变的发展产生不利影响。
