目的评价一种自主设计的髂骨钉垫片对腰-髂固定结构疲劳载荷前、后稳定性的影响。方法取自愿捐献的12具成人防腐尸体腰椎-骨盆标本,根据是否使用髂骨钉垫片随机分成A组(使用垫片)和B组(不使用垫片),每组6具。使用双能X线骨密度仪测定L1~4骨密度(bone mineral density,BMD)后,行双侧L3、L4、L5椎弓根钉和髂骨钉固定,并且切除L5、S1双侧关节突关节及椎间盘制作椎间失稳模型。在MTS材料试验机上,向标本施加0~600 N轴向压缩和—7~7 N.m轴向扭转载荷,测试固定结构初始压缩及扭转刚度。然后给标本施加2万次40~400 N循环压力载荷,重复刚度测试。最后,对所有螺钉进行轴向拔出测试,记录最大拔出力。植钉及加载过程中行大体及影像学观察。结果 A、B组BMD值分别为(1.15±0.13)g/cm2和(1.12±0.11)g/cm2,差异无统计学意义(t=0.428,P=0.678)。所有螺钉植入位置良好,加载过程中无钉棒松动及断裂。疲劳载荷后X线片示A、B组分别有1具(16.7%)和3具(50.0%)标本髂骨钉周围出现骨透亮带。A、B组疲劳载荷后压缩刚度和扭转刚度均低于疲劳载荷前(P<0...
【英文摘要】
Objective To evaluate the biomechanical e ect of a self-made iliac screw plate on the stability of lumboiliac xation construct before and after fatigue loading.Methods Twelve fresh lumbo-pelvic specimens from donated adult cadavers with formalin embalm were used in the study.According to whether use the iliac screw plate or not,the specimens were randomly assigned into group A(with iliac screw plate,n=6) and group B(without iliac screw plate,n=6).The bone mineral density(BMD) of L1-4was measured using dual-...