【作者】 马为民；

【导师】 钟世镇； 余斌；

【作者基本信息】 第一军医大学 ， 人体解剖学， 2002， 硕士

【摘要】 目的：近年来，交锁髓内钉已广泛应用于临床，特别是对长骨干骨折治疗疗效显著，但术后也存在一些并发症，断钉是严重并发症之一。本课题通过测定股骨交锁髓内钉锁钉的生物力学变化，旨在为临床分析锁钉断裂的原因，哪枚锁钉易发生疲劳断裂以及远端应该用几枚锁钉固定提供依据。 方法：六具青壮年防腐股骨标本，剔除软组织后远端用牙托粉包埋固定，测量长度并X线摄片以排除骨病，同时测量髓腔直径(髓腔最狭窄处)。标本用夹具固定后装于MTS试验机，锁钉处安装MTS位移传感器，轴向加载0-500N，加载速度为50N／sec，MTS自动加载，MTS位移传感器自动记录位移，计算机自动处理数据。每具标本分六个状态，按a-f组测量顺序进行重复测量：a，正常股骨；b，安装交锁髓内钉模拟骨折愈合；c，股骨中段横形或小斜形锯断模拟稳定型骨折；d，在c组的基础上远端去除一枚锁钉；e，在c组基础上股骨中段制成1.5cm骨缺损模拟不稳定型骨折；f，在e组基础上远端去除一枚锁钉。分别测量各锁钉处应变变化，并进行统计学分析(重复测量的方差分析)。 结果：各种状态下近端锁钉间应变均无显著性差异(p＞0.05)；近端锁钉与远端锁钉之间应变存在显著性差异(p＜0.05)；远端锁钉间应变除正常股骨及稳定型骨折外均存在显著性差异(p＜0.05)；远端去除一枚锁钉固定时剩余远端钉表现比原来大的应变。第一枚锁钉和第二枚锁钉的应变在稳定骨折及其远端去除一枚锁钉、不稳定骨折及其远端去除一枚锁钉的状态比较时无显著性差异(p＞0.05)，在其他状态之间均有显著性差异(p＜0.05)。第三枚锁钉在所有状态之间均有显著性差异(p＜0.05)。第四枚锁钉在正常股骨与骨折愈合后无显著性差异；其他状态之间均有显著性差异。 结论：骨折线远端的锁钉易发生断裂，尤其是靠近骨折线者；尽量以两枚锁钉固定远端并远离骨折线。骨折愈合后应及时取出内固定物，或者在有丰富的骨俪形成后去除锁钉，变静力型固定为动力型固定。更多还原

【Abstract】 Objective:The interlocking fixation has been widely used in clinics,especially in treating the limbs fractures. Though as an effective method,it also has many postoperative complications. Nail breakage is the most serious one. The study aims at analyzing the causes of interlocking nails breakage,which one tend towards failure fragmentation and how many nails should be put in distal fracture segment.Methods:Six antiseptic adult femora were used,clearing all soft tissue and coating the distal tip with dental base acrylic resin powder. All femoral were length measured and X-ray photographed to evacuate osteopathies and measure the diameters of medullary cavities. Specimen were fixed and installed on MTS machine,put on migration sensor on each inter-locking nail,axial compression was 0-500N,average 50N/sec,auto compressed by MTS machine,migration (or strain ) auto receded from sensors and data processed in computer. Each specimen tested under six conditions at (a)-(f) sequence:(a),normal;(b),install the interlocking intramedullary nail to simulate cured fracture;(c),saw an across or slope crack to simulate the stable fracture;(d),as(c) and remove a distal interlocking nail;(e),as (c)and saw asunder a 1.5cm fragment to simulate unstable fracture;(f),as(e)and remove one distal nail. Measured the stress and strain changes on every interlocking nail and did the statistical analysis.Results:All six conditions showed no notable stress and strain changes at proximal interlocking nails (p>0.05);which were significant between distal and proximal (p<0.05);stress and strain had the outstanding changes in distal ones except the normal and stable fracture groups (p<0.05);those groups removed one distal interlocking nail,another one should endure much stressand had more strain. The stress and strain changes on the first and second interlocking nail were not significant at those unstable fractures and with one of their distal nails removed,but significant at other conditions. The third nail happened marked changes at every conditions. The forth one had the significant changes except the normal and cured fractures. Conclusions:Interlocking nails under the crack tend towards broken especially very near it,as far as possible apply two nails interlocking the distal fracture and apart from the crack. Internal fixation instruments should be removed at time when the fractures had cured or removed the interlocking nails when had the sufficient bony callus,which turn the quiescenced fixation into mobilized fixation.更多还原