颈椎间盘切除前路钢板内固定术对相邻节段影响的生物力学研究

Biomechanical evaluation of the adjacent segments after anterior cervical discectomy and plant fixation

目的研究颈椎前路钢板内固定对相邻节段椎体、椎间盘和关节突等结构的生物力学特性的变化。方法采用5具新鲜人体颈椎标本先作为正常空白的对照组,测试其生物力学特性后再依次进行前路单节段钢板内固定和双节段钢板内固定,测试相邻节段椎间盘和关节突上应变和位移变化。结果前路钢板内固定后,在固定节段上方相邻节段测试应变、位移除前屈位外均明显增加(P＜0．05),最大变化发生在后伸位。而单节段和双节段钢板固定相比,仅有数值上的差别,无统计学意义(P＞0．05)。结论前路Orion钢板内固定后,固定节段的活动度转移到邻近节段,其上方相邻节段活动度增加,应力集中,负荷增加,当处于后伸位时有明显的提高。固定节段选择统计学差异不明显。

Objective To evaluation the biomechanical changes on the vertebral body,annuli fibrosis and faced joint of the adjacent segments on the condition of anterior cervical discectomy and plant fixation. Method To measure five cervical spine specimens scope of dimensional and variety of stress on 3 conditions： normal, single segment plant fixation and double segment plant fixation. Each group was measured under the loading of states of vertical compression, flexion, extension and lateral bending. Result After anterior cervical discectomy and plant fixation, at the adjacent segment ,the stress, displacement increased significantly except the state of flexion （P〈0.05）. When the double segment plant fixation compared with the single segment,there was no statistical differences. Conclusion Anterior cervical discectomy and plant fixation can improve the stress and displacement significantly at the adjacent segments,maximum at the state of extension. But there was no statistical differences of the segment selection.