体积骨密度与椎弓根螺钉稳定性的相关性及磷酸钙陶瓷的强化效应  

Correlafion of volumetric bone mineral density with the stability of pedicle screw fixation and the effect of calcium phosphate cement augmentation

作　　者：邵景范[1] 杨小进[1] 李贵林[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院小儿骨科,武汉430030

出　　处：《中国骨质疏松杂志》2005年第3期321-324,共4页Chinese Journal of Osteoporosis

摘　　要：目的探讨椎体松质骨体积骨密度对椎弓根螺钉稳定性的影响,以及添加磷酸钙陶瓷的效应。方法用pQCT测定16个腰椎的体积骨密度,将USS椎弓根螺钉分别置入两侧椎弓根,植入螺钉前随机在其中一侧钉道内添加磷酸钙陶瓷;测试螺钉最大轴向拔出力(Fmax),计算骨螺钉界面的剪切应力(η)。结果随体积骨密度提高,Fmax和η亦逐次增加。无论是否添加磷酸钙陶瓷,Fmax和体积骨密度始终呈较强的正相关关系(r=0.9056和0.9585,P<0.05)。添加磷酸钙陶瓷后Fmax和η均增加了约80%(Wilcoxonstest,P<0.01)。结论椎弓根螺钉的稳定性与体积骨密度紧密相关,磷酸钙陶瓷有明显的强化效应。Objective To evaluate the correlation of volumetric bone mineral density（VBMD） with the stability of pedicle screw fixation in the human lumbar spine and the augmentation effect of calcium phosphate cement on pedicle screw fixation. Methods VBMD of the human cadaveric lumbar vertebral bodies were measured by peripheral quantitative computer tomograph （ pQCT）. Sixteen human cadaveric lumbar vertebral bodies （ L3 - L5 ） were instrumented with USS pedicle screws using the standard procedure bilaterally and calcium phosphate cement was randomly inserted unilaterally. The maximum axial pull-out strength and the cut-strength of the screw-bone interface（η） were compared between the control screws and those augmented with calcium phosphate cement. Results The maximum axial pull-out strenght and η of the augmented pedicles averaged at 80% greater than that of the control side（ P 〈 0.01 ）. The linear correlation coefficient between VBMD and maximum axial pull-out strength was 0.906（control side） and 0.959（ augmented side）. Conclusions The data suggest that the stability of pedicle screw fixation in the human lumbar spine were influenced by VBMD and augmentation with calcium phosphate cement can enhance immediate screw fixation in osteoporofic human vertebrae.

关 键 词：骨密度 骨螺丝钉 稳定性 磷酸钙陶瓷 USS椎弓根螺钉 磷酸钙陶瓷 体积骨密度 强化效应 稳定性 椎体松质骨 PQCT 剪切应力 test 

分 类 号：R681.5[医药卫生—骨科学] R318.08[医药卫生—外科学]