颈椎前路不同方式减压固定对颈椎稳定性影响的生物力学研究

Biomechanical effects of different anterior decompressions on the stability of cervical vertebra

目的:研究颈椎前路多节段病变不同减压、融合固定方式对生物力学稳定性的影响。方法:18具新鲜人尸体颈椎标本,分别行前路椎间盘切除植骨融合(ACDF)、分节段混合减压植骨融合(ACHDF)及椎体次全切除植骨融合(ACCF)术,依次测定正常状态、减压植骨后、钢板固定后、疲劳2000次后的三维活动度,计算稳定潜能指数(SPI),测定疲劳2000次后尾端螺钉和椎体间的活动度。结果:3种方式减压、植骨、钢板固定后,稳定性均明显提高;屈伸疲劳1200次后,ACDF、ACHDF组标准化的螺钉—椎体间活动度曲线无变化,而ACCF组曲线升高;疲劳2000次后,ACDF组三维运动SPIROM及SPINZ无变化,ACHDF组轴向旋转SPINZ降低,而ACCF组三维运动SPIROM及SPINZ均降低,统计学处理差异具有显著性(P<0.05)。结论:颈椎3节段病变3种手术方式均可恢复即刻稳定性,ACDF和ACHDF疲劳后仍保持较好稳定性,而ACCF组耐受疲劳性较差,节段间活动度增大,远端螺钉松动,稳定性降低。

Objectives：To study biomechanical effects of different anterior decompression and fusion on the stability of cervical vertebrae. Methods： 18 cadaveric specimens of cervical spine were divided into three group randomly：①anterior cervical discectomy and fusion （ACDF）; ②anterior cervical hybrid decompression and fusion（ combined with corpectomy and discectomy （ACHDF） ; ③anterior cervical corpectomy and fusion （ACCF）; Specimens of every group endured the movements of flexion, extension, lateral bending, and axial rotation. The range of motion of all directions was recorded stereophotogrammetrically after flexion-extension fatigue loading of 2000 cycles on the specimens of 3 groups. Results： Anterior plate made all of specimens more stable. After flexion-extension fatigue loading of 1200 cycles, there were no changes of ROM between ACDF and ACHDF groups, however, ROM of ACCF group increased. After 2000 cycles, SPIROM and SPINZ of ACDF and ACHDF groups had no difference, however, that of ACCF group decreased. Conelusions： Three kinds of anterior decompression and fusion technique could restore the stability of cervical vertebrae. Under the fatigue loading, the stability and tolerance of ACDF and ACHDF groups are superior to that of ACCF group.