Vertebral Biomechanics Analysis in PKP Operation with Different Proportion of Bone Cement Perfusion

Objective To analysis of the changes of biomechanical properties vertebral body after kyphoplasty(PKP) according to the different proportion of balloon volume and provide reference data for clinical treatment.Methods 36 fresh adult porcine thoracolumbar vertebral,were preserved in formaldehyde for 24 hours,then EDTA-Na 2 for 20 days.All the samples were randomly divided into 4 groups,After detection of vertebral body bone mineral density(BMD),the vertebral body were placed vertically in the universal material testing machine,measure the vertebral body strength and stiffness,record anterior vertebral height of each vertebra.The vertebrae underwent PMMA kyphoplasty according to different proportion of balloon volume.We record the balloon volume,the balloon pressure,the anterior height of vertebral body and bone cement leakage vertebral number.Then the second biomechanical testing was done.Results After PKP,vertebral strength and stiffness were statistically significant different(P 0.01);after PKP vertebral strength and stiffness between A and B were no statistic significance(P 0.05) between A B and C D vertebral strength and stiffness were statistically significant(P 0.01);After PKP four groups of vertebral height restoration were not statistically significant(P 0.05);the bone cement leakage of A and B was 0,the bone cement leakage rate of C was 22.22%,D was 44.44%.Conclusion In accordance with the balloon volume 0.8 ~ 1 times injection of bone cement can effectively restore the biomechanical properties of osteoporotic compression fractures vertebral body,but also can reduce the leakage of bone cement;In accordance with the balloon volume of 0.8 ~ 1 times the perfusion of bone cement could be partially restored the height of vertebral body,with its high proportion of perfusion group showed no significant difference;Balloon volume can be used as a reference index of bone cement perfusion dose.