geneX骨水泥强化骨质疏松椎体椎弓根钉的生物力学研究

目的评估骨质疏松情况下geneX骨水泥强化椎弓根钉的固定强度。方法应用微量注射泵对30个新鲜小牛腰椎标本注射稀盐酸建立骨质疏松椎体模型。60个椎弓根分为四组:geneX骨水泥组,硫酸钙骨水泥(CSC)组,聚甲基丙烯酸甲酯骨水泥(PMMA)组,对照组。随机选择一侧注射2.5 ml骨水泥,然后置入螺钉;另一侧行正常螺钉固定对照,应用材料试验机进行轴向拔出力测试,记录各组的轴向最大拔出力和能量吸收值并进行比较。结果 geneX组与CSC组两组拔出力及能量吸收值比较,差异无统计学意义(P>0.05),两组均显著低于PMMA组(P<0.05),两组均显著高于对照组(P<0.05)。结论 geneX骨水泥强化椎弓根钉可显著提高椎弓根固定强度,geneX骨水泥可用作椎弓根强化螺钉的填充材料。

Biomechanical study of geneX cement augmentation of pedicle screw in osteoporotic calf vertebra model

Objective To evaluate the biomechanical effects of geneX cement augmentation of pedicle screw in osteoporotic calf vertebra model.Methods Thirty vertebral bodies were harvested randomly for biomechanical tests and bone mineral density measurements was measured with dual-energy radiographic absorption.Each vertebral body was established into osteoporotic calf vertebra model by utilizing decalcifying chemical agents.Both vertebral pedicle were selected randomly into four groups:geneX cement group,CSC group,PMMA group,control group.In each vertebral body,2.5 ml bone cement was injected into either the right or left prepared pedicle and then the screws were inserted.As a control,a screw was inserted into the contralateral hole of each vertebra without bone cement.Pull-out tests were performed using a mechanical testing machine,and the pull-out strength and energy were recorded.Results The pull-out strength and energy absorption of geneX,CSC and PMMA were significantly greater than that of intact control group respectively(P <0.05).There was no significant difference between geneX and CSC(P >0.05).Injection of PMMA produced significantly higher pullout strength than the injection of geneX and CSC(P <0.05).Conclusion geneX cement augmentation of the pedicle screw increases the strength of screw-bone interface,geneX cement augmentation of the pedicle screw may be a viable clinical option for the augmentation of pedicle screw fixation.