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

English Keywords:Ｂiomechanics  Ｐercutaneous kyphoplasty  Ｂone cement  Ｌateral compression

English Abstract:

  【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.