单侧PKP骨水泥注射过中线分布对压缩性骨折椎体两侧刚度的影响

Effects of cross-midline cement distribution on the stiffness of varied sites in compressive fractured vertebrae after unipedicular PKP：a biomechanical study

中文关键词:  生物力学  经皮椎体后凸成形术  骨水泥  侧方压缩

英文关键词:Ｂiomechanics  Ｐercutaneous kyphoplasty  Ｂone cement  Ｌateral compression

中文摘要:

  【摘要】 目的：评价单侧椎体后凸成形术（PKP）中骨水泥注射超越椎体中线与否对椎体轴向及两侧刚度的影响。方法：3具防腐成人胸腰椎椎体标本（T4～L1）用于实验。通过MTS平台给椎体施加轴向压力，制作压缩性椎体骨折模型，同时进行球囊辅助下经单侧椎弓根穿刺椎体后凸成形术，根据骨水泥是否过椎体中线分为两组，骨水泥注射不过椎体中线（A组，n=9）；骨水泥注射过椎体中线（B组，n=8），骨水泥注射量为椎体体积的10%。24ｈ后放置在MTS-858材料实验平台上，给标本分别施加0~300N轴向和侧方压力载荷，记录并比较骨水泥注射术后，两组椎体轴向及两侧的刚度差异。结果：轴向压缩载荷下，A组与B组间轴向压缩刚度无显著差异（P>0.05）；在椎体侧方压缩载荷下，尽管A组椎体骨水泥穿刺侧的刚度与B组间差异无显著性（P>0.05）；但在非穿刺侧刚度上，B组显著高于A组，差异有显著性（P<0.05）。结论：行单侧PKP时，若骨水泥填充不过椎体中线时，则非穿刺侧刚度明显低于穿刺侧，而骨水泥填充过中线时，则两侧椎体刚度可同时得到显著强化。

英文摘要:

  【Ａbstract】　Objective：To evaluate the effects of cross-midline cement injection on axial and bilateral vertebral stiffness　of varied sites in compressive fractured vertebrae after unipedicular PKP.Method：Vertebral bodies harvested from 3 cadaver spines（T4-L1） were experimentally induced into compressive vertebral fractures models by MTS.Subsequently the specimens were stabilized using transpedicular balloon-assisted PKP（group A，n=9，unipedicular hemivertebral，non cross-midline cement injection，group B，n=8，unipedicular cross-midline cement injection） and the volume of cement filling were 10% of the vertebral body.Then the stablized vertebral bodies were subjected to axial and sided compression loads（0-300N，cycled）　by MTS 24 hours later.After that，the stiffness was measured and compared between the two groups.Result：Under axial loading，the stiffness between group A and B showed no significant difference（P>0.05）.While under sided compression loading，despite of no difference of stiffness in penetration side between group A and B（P>0.05），the stiffness in non-penetration side in group B increased more than that in group A（P<0.05）.Conclusion：When performing unipedicular balloon-assisted kyphoplasty，cross-midline cement distribution or not will impact the side-related stiffness significantly.