摘要
目的:了解椎弓根螺钉把持椎弓根皮质骨对椎弓根螺钉固定强度的影响.方法:将成年羊腰椎椎弓根48个依据椎弓根皮质骨内径和椎弓根螺钉直径(6.25mm)的相对关系分为三组:A组,螺钉直径小于椎弓根皮质骨内径;B组,螺钉直径超出椎弓根皮质骨内径0.01～0.50mm;C组,螺钉直径超出椎弓根皮质骨内径0.51～1.00mm.每组再根据进钉深度与椎弓根长度(平均约8mm)的相对关系分为Ⅰ(进钉深度为16mm)、Ⅱ(进钉深度为8mm)两组.将椎弓根螺钉置入椎弓根中,观察钉道结构、膨胀情况,测量椎弓根螺钉最大轴向拔出力.结果:椎弓根螺钉置入后,椎弓根发生不同程度膨胀;椎弓根螺纹能够切入皮质骨中;C Ⅰ组最大轴向拔出力比AⅠ组和B Ⅰ组大(P＜0.05),CⅡ组最大轴向拔出力比AⅡ组和BⅡ组大(P＜0.05),BⅡ组比AⅡ组大(P＜0.05).结论:椎弓根螺钉把持椎弓根皮质骨能够增加椎弓根螺钉的固定强度;且椎弓根螺钉把持椎弓根皮质骨量越大,固定强度越大.
Objective：To explore the effect of holding of the pedicle cortical bone on the fixation strength of the pedicle screw.Method：48 pedicles of lumbar vertebrae of adult sheep were divided into 3 major groups as group A（the diameter of the screw was less than the inner diameter of the pedicle cortical bone）,group B （the diameter of the screw was larger than the inner diameter by 0.01-0.50mm） and group C（the diameter of the screw was larger than the inner diameter by 0.51-1.00mm）.Every major group was divided into 2 subgroups respectively： Ⅰ （the depth of the screw placement was 16ram） and Ⅱ （the depth of the screw placement was 8mm）.Then the screw was implanted into the pedicle,the screw canal and pedicle expansion were observed,the maximum axial pullout force was measured.Result：After screw implantation,the pedicle was expanded which permit the thread of large screw cutting into the cortex.The pullout force of the C Ⅰ is largerthan A Ⅰ and B Ⅰ （P〈0.05）,the pullout force of the C Ⅱ is larger than A Ⅱ and B Ⅱ （P〈0.05）,and the pulloutforce of the B Ⅱ is larger than A Ⅱ （P〈0.05）.Conclusion：Holding of the pedicle cortical bone can improve the fixation strength of the screw.The more cortical bone the screw holds, the higher strength the screw offer.
出处
《中国脊柱脊髓杂志》
CAS
CSCD
2005年第7期429-432,共4页
Chinese Journal of Spine and Spinal Cord
