两种不同方法提高椎弓根螺钉稳定性的体外生物力学研究  

Study on Biomechanical Comparison between Two Different Methods of Augmenting Pedicle Screw Stability in Vitro

作　　者：刘达[1] 吴子祥[1] 雷伟[1] 高明暄[1] 石磊[1] 王军[1] 吕荣[1] 李丹[1] 

机构地区：[1]第四军医大学西京医院全军骨科研究所,陕西省西安市710033

出　　处：《中国骨与关节损伤杂志》2011年第1期38-41,共4页Chinese Journal of Bone and Joint Injury

基　　金：基金项目：国家高技术研究发展计划项目（863计划）（2007AA022468）

摘　　要：目的比较膨胀式椎弓根螺钉（EPS）与骨水泥（PMMA）强化方法在体外提高螺钉稳定性的效果。方法将60个新鲜成年绵羊腰椎随机分为三组。普通椎弓根螺钉组（CPS组）：直接拧入普通椎弓根螺钉;PMMA-PS组：向钉道内注入PMMA（1.0 ml）后拧入CPS;EPS组：直接拧入EPS。24 h后对所有标本进行X线检查,随后进行生物力学实验。结果各组中螺钉位置良好,EPS均膨胀良好。EPS组和PMMA-PS组中螺钉的稳定性均显著强于CPS组（P〈0.05）,而EPS组与PMMA-PS组之间的差异无统计学意义（P〉0.05）。结论 EPS可以显著提高螺钉的稳定性,其效果接近目前临床上常用的PMMA强化方法。同时,EPS可以有效的避免因增加螺钉直径和使用PMMA可能带来的椎弓根骨折和渗漏、压迫等风险。EPS具有广阔的临床应用前景。Objective To compare stability of expansive pedicle screw（EPS） and polymethylmethacrylate-augmented pedicle screw（PMMA-PS） in vitro in sheep lumbar vertebrae.Methods Sixty adult sheep lumbar vertebrae were randomly divided into three groups.A pilot hole was prepared in advance using the same method in all samples.Then,conventional pedicle screw（CPS） was inserted in CPS group,the pilot hole was filled with PMMA followed by insertion of CPS in PMMA-PS group and EPS was inserted in EPS group.Twenty four hours later,X-ray examination was performed to all samples.Then,axial pull-out tests,turning-back tests,and cyclic bending resistance tests were performed to evaluate the screw stability.Results No malpositioned screw was detected in all groups in X-ray examination.EPS were all expanding well.Biomechanical data revealed that both axial stability and vertical stability of screws in both EPS group and PMMA-PS group were significantly enhanced compared with those of screws in CPS group（P〈0.05）.But there was no significance on both axial stability and vertical screw stability between EPS group and PMMA-PS group（P〉0.05）.Conclusion EPS can significantly increase screw fixation strength with the statistically similar effect as the wide-used traditional method of screw augmentation with PMMA.It can overcome pedicle fracture and leakage and compression caused by lager screw and augmentation with PMMA,respectively.Furthermore,the insertion of EPS will not cost more operation time and trauma.As an effective,safe and easy method,EPS has a great application potential in augmentation of screw stability in clinic.

关 键 词：骨质疏松 膨胀式椎弓根螺钉 普通椎弓根螺钉 骨水泥 生物力学 

分 类 号：R683.2[医药卫生—骨科学]