Xing Ze-Jun, Wu Zhi-Hong, Niu Wen-Xin, Yan Jia-Zhi, Wang Xue-Song, Wang Chu, Hao Dong-Sheng, Fan Yu-Bo, Qiu Gui-Xing
Department of Orthopaedics, Beijing Chuiyangliu Hospital, Beijing 100022, China.
Zhonghua Yi Xue Za Zhi. 2011 Feb 22;91(7):477-81.
To study the stress distribution of the adjacent different grades of disc degeneration underwenting unilateral laminectomy and discectomy surgery using non-linear finite element analysis.
Based on the lumbar CT scans, the finite element model (FEM) of lumbar spinal segment (L3-L5) was established. According to L3-L4 intervertebral disc degeneration, different grades of disc degeneration (healthy, mild, moderate and severe) models were established and unilateral laminectomy and discectomy surgery were also established. Physiological action such as flexion, extension, lateral bending and lateral rotation was simulated and the von Mises stress in the nucleus pulposus and annulus fibrosus matrix of L3-L4 disc was investigated.
After unilateral laminectomy and discectomy surgery, the extremum value of von Mises stress of nucleus pulposus and annulus fibrosus matrix was maximum during extension and minimus left bending in the healthy intervertebral disc. Compared with healthy disc, the increment of extremum value was found during left bending in the mildly degenerated disc. When the value decreased in the moderately degenerated disc, but still higher than that in the healthy disc. When the adjacent disc is severely degenerated, the extremum value of nucleus pulposus decreased, in addition to axial rotation, and even lower than that of healthy disc. The value of annulus matrix decreased and still higher than that of healthy disc, especially during left bending.
After unilateral laminectomy and discectomy surgery, avoiding lateral bending will reduce the abnormal stress in the degenerated disc and decreased the risk of accelerating disc degeneration.
采用非线性有限元分析研究单侧椎板切除术和椎间盘切除术对相邻不同程度椎间盘退变的应力分布影响。
基于腰椎CT扫描，建立腰椎节段（L3-L5）的有限元模型（FEM）。根据L3-L4椎间盘退变情况，建立不同程度椎间盘退变（健康、轻度、中度和重度）模型，并进行单侧椎板切除术和椎间盘切除术。模拟屈伸、侧屈和侧旋等生理动作，研究L3-L4椎间盘髓核和纤维环基质中的von Mises应力。
单侧椎板切除术和椎间盘切除术后，健康椎间盘在伸展时髓核和纤维环基质的von Mises应力极值最大，左侧弯曲时最小。与健康椎间盘相比，轻度退变椎间盘在左侧弯曲时极值增加。中度退变椎间盘时该值下降，但仍高于健康椎间盘。当相邻椎间盘严重退变时，除轴向旋转外，髓核极值下降，甚至低于健康椎间盘。纤维环基质值下降，但仍高于健康椎间盘，尤其是在左侧弯曲时。
单侧椎板切除术和椎间盘切除术后，避免侧屈可减少退变椎间盘中的异常应力，降低椎间盘退变加速的风险。
