颈椎前路椎体开槽减压植骨的稳定性研究

Physical stability of anterior cervical decompression by slotting vertebral body with bone graft

目的 研究颈椎前路椎体开槽减压及植骨对颈椎运动稳定性的影响 ,为临床手术提供理论依据。方法 取新鲜尸体标本 8具 ,对每一具标本先后进行正常预柱、前路椎体开槽和开槽后植骨 3种工况测试 ,在脊柱三维运动实验机上对颈椎标本施加 2 .0Nm的纯力偶矩产生颈椎生理范围的运动 ,应用计算机图像处理及脊柱运动分析程序测量C4～ 5及C5～ 6在载荷条件下三维六自由度的稳定性。结果 颈椎前路开槽减压后 ,减压节段的稳定性明显降低 ,表现为减压节段屈伸、侧弯及旋转活动度加大。植骨后前屈活动度下降 ,但稳定性较正常差。结论 颈椎开槽后稳定性明显降低。植骨后椎间高度增加 ,椎间活动度减少即稳定性增加 ,但较正常差。

Objective To study the physiological stability of anterior decompression by slotting the vertebral body without and with bone grafting. Methods Eight fresh cervical spine specimens of young cadaver were used for physiological test in three working conditions at C 5～6 and C 4～5 simulating clinical surgery ,and then six pure movements of 2.0 Nm were carried out in flexion ,extension ,bilateral bending ,bilateral axial rotation, and then three dimensional movements were determined by stereophotography. The stabilities of C 5～6 and C 4～5 were analyzed. Results The stabilities of C 5～6 and C 4～5 were significantly decreased after anterior decompression by slotting the vertebral body without bone graft that exhibited as the increasing of range of motion(ROM) in flexion ,extension ,bilateral bending ,bilateral axial rotation. After the implanting graft into intervertebral slotting space , resulted in decreae of the ROM of the C 5～6 and C 4～5 segments as well as no change in the range of extension, but its stability is inferior to that of the normal segment. Conclusion The stability of cervical spine was significantly decreased by slotting the vertebral body without bone graft, and bone graft at intervertebral space can significantly improve the stability of the cervical spine.