腰椎椎弓崩裂直接修复的不同内固定生物力学分析-biomechanical analysis of different internal fixation for direct repair of lumbar spondylolysis.docxVIP

腰椎椎弓崩裂直接修复的不同内固定生物力学研究研究生樊健导师刘瑶教授1摘要l目的对四种腰椎椎号崩裂直接修复的内固定方法进行 生物力学实验研究。方法选用 8 具新鲜小牛 L2-L6 脊柱标本争正常 标本作为对照级古然后制成 L4 双侧椎号崩裂模型，分别以改良 Sco坑 法、钧螺钉法、钉杆法和 Buck 螺钉法固定事通过计算机扫描进行脊 柱三维稳定性的研究。结果腰椎椎号崩裂后其稳定性明显降低 (PO.05 )，采用上述四种内固定后?在脊柱稳定性方面?四种内固 定固定后脊柱稳定性均能得到有效恢复 (PO.05 )且四种内固定之间 无显著性差异 (PO.05 )。但在旋转位时改良 Scott 法、钩螺钉法、钉 杆法二者均数更接近正常值。结论改良 Scott 法、钩螺钉法、钉杆法 和 Buck 螺钉法符合脊柱生物力学，均能有效恢复失稳脊柱的稳定性; 但前三者在维持旋转稳定性方面更具优势，并且操作简单、易行、安 全有效，是较理想的直接修复内固定器。关键词:腰椎椎号崩裂直接修复不同内固定生物力学2Biomechanicalstudy in the direct repair of spondylolysis by different fixations[Abstract} Object: To compare bion1echanica l1y the perfonnance of different fixation techniques for the repair of spondylolytic defects in theparsinterarticularis.Method: Eight fresh-frozen and thawed calf cadavericlumber spine were used for mechanical testing. Modified Sco仗， s technique(wire loops around corti.cal screw placed into bothpedicles and tightened under the spinous process with com) 、Screw-rod-hook technique 、Rod-screw construct fixation and Buck s technique(screw fixation in the lamina across the defects) were applied onthe calf lumber spines in which bilateral spondylolytic defects were created in the L4 vertebra l.The intervertebral rotation for each direction of loading in 1ateraI bendirig 、flex?on.. extension and torsion were measured by scanning and computed 企om the acquiredload-displacement data.Result: For the un?nstrumented spondylolytic spines，the intervertebral rotations were significantly greater than in the i.ntact spìnes and in the instrumented spondylolytic spines (PO.05 ) ;thisrotationwas retumed to nearly the intact level by all this methods ( PO.05) ，there was no significantly different between any two ofthem C PO.05) .But the former three methods 哇 means are closer to that of theintace than Buck in torsion. Conclusion: All four fixation techniques3accorded with the spinal bioluechanical principle and restored the intervertebral rotation displacements under f1exion 、extension an