摘要
【目的】对侧后方融合与经后路椎体间融合进行生物力学比较,探讨腰椎重建术式的选择方法。【方法】10具小牛尸体腰椎标本(L3-L6)用于实验。从L4-L5后方破坏腰椎稳定结构,并用椎弓根钉固定(PSF)和椎体间cage行以下重建:①完整脊柱+PSF,②两侧关节突关节内侧切除+PSF,③两侧关节突关节全切+PSF,④椎间盘部分切除+PSF,⑤椎间盘部分切除+PSF/cage。各组均行载荷量为5N·m的前-后屈曲测试,记录固定椎间(L4-L5)的刚度值及L4螺钉的应变量,并比较。【结果】除椎间盘部分切除+PSF外所有重建组的脊柱刚度均显著大于完整脊柱组,椎间盘部分切除+PSF/cage组在所有的固定组中获得最大的脊柱刚度。椎间盘部分切除+PSF组在所有的重建组中螺钉的应变量最大,而椎间盘部分切除+PSF/cage组的螺钉的应变量在所有重建组中最小。【结论】若脊柱前方的承载能力尚存,使用PSF的侧后方融合可获得充分的力学稳定性。当脊柱前方丧失其承载能力,单纯PSF的脊柱刚度低,螺钉的应力显著增大。对此种病例,cage的使用可增加重建脊柱的初期稳定性,有利于降低后方固定器械的应力。
[Objective] To compare biomechanics in posterolateral fusion and posterior lumbar interbody fusion, and texplore he ideal reconstruction method for each lumbar instability.[Methods] Ten calf spines （L3-L6） were used. Sequential destabilization was performed at L4-L5 and followed by posterior reconstruction using the pedicle screw fixation （PSF） and interbody cages as follows： （1） intact spine ＋ PSF, （2） bilateral medial facetectomy ＋ PSF, （3） bilateral total facetectomy ＋ PSF, （4） partial discectomy ＋ PSF, and （5） partial discectomy ＋ PSF ＋ interbody cages. Biomechanical testing was performed under 5 Nm flexion and extension loading modes. Construct stiffness （L4-L5） and IA screw bending strain were analyzed. [Results] All reconstructions except DPSF demonstrated significantly higher construct stiffness than the intact spine; DPSFC revealed the highest stiffness among the all reconstructions. DPSF resulted in significantly higher strain compared to the other groups; The DPSFC presented statistically less strain than the other reconstructions.[Conclusions] For spinal instability with preserved anterior load sharing, PLF using PSF is biomechanically adequate. However, PSF alone demonstrated insufficient stability and high implant strain following partial discectomy. In such cases, additional interbody cages significantly increase construct stiffness and decrease hardware strain.
出处
《中山大学学报（医学科学版）》
CAS
CSCD
北大核心
2005年第5期511-514,共4页
Journal of Sun Yat-Sen University:Medical Sciences
基金
日本医学振兴协会科研基金资助项目(2002010239)
关键词
腰椎
侧后方融合
经后路椎体间融合
生物力学
椎弓根钉固定
lumbar spine
posterolateral fusion
posterior lumbar interbody fusion
biomechanics
pedicle screw fixation
