摘要
目的:比较腰骶融合椎弓根螺钉三皮质固定技术与双皮质固定技术的最大旋入力矩,明确最大旋入力矩与骨质密度的关系。方法:实验于2002-10/2004-01在河北省骨科研究所生物力学实验室完成。选择10具新鲜成人的腰骶椎骨骼标本,先用双能X射线吸收仪测量每具标本的骨质密度。分别向骶骨岬方向置入(三皮质固定技术或平行终板方向置入双质固定技术)一枚7.5mm椎弓根螺钉,用)(扭转传感器测量螺钉每旋转一圈所产生的最大力矩以及螺钉旋入总长度的10%,20%,30%,40%,50%,60%,70%,80%,90%,100%时的最大旋入力矩,并加以比较分析。结果:全组标本的平均骨质密度为(0.940±0.232)g/cm(0.600～21.432g/cm)。应用三皮质固定技术时,螺钉最大旋入力矩与骨质密度2呈正相关关系(r=0.832,P=0.003),而应用双皮质固定技术时,螺钉最大旋入力矩与骨质密度无相关关系(r=0.544,P=0.104)。三皮质固定技术螺钉最大旋入力矩明显大于双皮质固定技术螺钉最大旋入力矩(P<0.05)。结论:腰骶融合椎弓根螺钉的三皮质固定技术的最大旋入力矩较双皮质固定技术的最大旋入力矩增加了98.6%,具有一定的生物力学优势。骨质密度与三皮质固定技术的最大旋入力矩直接相关,可以作为三皮质固定技术的最大旋入力矩的预测因素。
AIM:To compare the maximal insertional torque of tricortical pedicle screw fix ation versus bicotrcal pedicle screw fixation in lumboscaral fusion and confirm the relationship between the maximal insertional torque and bone mineral density (BMD). METHODS:This experiment was conducted in the Hebei Provincial Research Institu te of Orthopaedics from October 2002 to January 2004.Lumbosacral vertebral bone specimens of 10 fresh frozen cadaver sacra were harvested and evaluated with dua l energy radiograph absorptiometry to assess BMD.Under direct visualization,7.5 mm monoaxial stainless steel pedicle screws were placed parallel to end plate( bicotrcal technique) or into the apex of the sacral promontory(tricortical techn ique).Maximum insertional torque was recorded and matched for each screw revolut ion and 10%,20%,30%,40%,50%,60%,70%,80%,90%,100%of total screw length with a torsion transducer. RESULTS:The mean BMD was(0.940±0.232) g/cm2(0.600 to 1.432 g/cm2) in all the specimens.The BMD was positively correlated with maximal insertional torque the tricortical technique(r=0.832,P=0.003),but not correlated with the maximal inse rtional torque for the bicortical technique(r=0.544,P=0.104).Maximum insertional torque of tricortical technique was larger than that of bicortical technique(P< 0.05). CONCLUSION:Compared with bicortical screws,the tricortical screws used for lum bosacral fusion resulted in an average 98.6%increase in maximal insertional tor que,and are of biomechanical advantage.BMD fixation correlates directly with max imal insertional torque of tricortical technique and can act as a predictor for it.
出处
《中国临床康复》
CSCD
北大核心
2005年第2期95-97,共3页
Chinese Journal of Clinical Rehabilitation
