帽式颈椎椎间融合器的生物力学性能研究

A biomechanical study of hat type cervical intervertebral fusion cage

目的:测试自行研制的帽式颈椎椎间融合器(HCIFC)的生物力学性能,探讨其用于颈椎椎间融合的可行性。方法:个羊颈椎标本随机分为组,组,完整颈椎节段;组,自体三面皮质髂骨;组,486ABCHarmscage;D组,SyncageC;E组,Carboncage;F组,HCIFC。除A组外均完全切除C3/4椎间盘后置入以上颈椎内置物,进行生物力学测定,计算出各组平均刚度及体积相关刚度,并行统计学比较。结果:置入HCIFC后颈椎屈曲刚度显著增大,而伸展、侧屈和轴向旋转刚度无变化;SyncageC在各方向上的刚度均最大,HCIFC与Carboncage相似;HCIFC在屈曲、伸展和侧屈刚度上小于Harmscage,而轴向旋转刚度显著大于Harmscage。与移植的三面皮质髂骨相比,所有cage在体积相关刚度上均有显著增加。Harmscage在各个方向上的体积相关刚度显著大于其它cage,其次为SyncageC、HCIFC及Carboncage。结论:HCIFC可为颈椎椎间融合提供足够的初始生物力学稳定性。

Objective:To evaluate the biomechanical effect of hat type cervical intervertebral fusion cage(HCIFC).Method:48 goat cervical spines(C2-C5) were tested in flexion,extension,axial rotation,and lateral bending with a nondestructive stiffness method using a nonconstrained testing apparatus,and three-dimensional displacement was measured.Autologous iliac bone and cervical spine intervertebral fusion cage were implanted according to manufacturers′ information after complete discectomy(C3/4) was performed.Eight spines in each of the following groups were tested:intact,autologous iliac bone graft,Harms cage,Syncage C,Carbon cage and HCIFC.The mean apparent stiffness values were calculated from the corresponding load-displacement curves.Additionally,cage volume and volume-related stiffness was determined.Result:The stiffness of the Syncage C was statistically greatest in all directions.After implantation of HCIFC,flexion stiffness increased as compared with that of the intact motion segment.There was no significantly difference in stiffness between HCIFC and Carbon cage.The stiffness of HCIFC was statistically higher than that of Harms cage in axial rotation and significantly lower in flexion,extension and lateral bending.Volume-related stiffness of all cages was higher than that of iliac bone graft.Harms cage was highest in volume-related stiffness of all directions.Conclusion:HCIFC can provide enough primary stability for cervical intervertebral fusion.