腰骶椎终板生物力学特性的实验研究

Biomechanical research on the properties of the lumbosacral endplates

目的:研究腰骶椎终板不同位点的生物力学特性及其分布规律。方法:选用成人新鲜尸体腰骶椎标本(L1～S1)5具,共30个椎体55个终板,应用电子万能实验机(型号CSS-2205)对终板平面49个测试点用直径1.5mm的平底压头以12mm/min的速度进行连续压缩加载实验,记录最大压缩力,并对数据进行统计分析。结果:(1)L1～S1上终板最大压缩力从68.81±8.12N增加至120.41±34.33N,各节段间差异有显著性(P<0.05);L1～L4下终板最大压缩力从78.66±5.57N增加至120.44±29.27,L5降为106.65±16.10N,各节段间差异有显著性(P<0.05)。(2)L1～S1上终板中央至外周最大压缩力从65.02±6.40N增加至110.61±10.63N,下终板中央至外周最大压缩力从68.09±9.43N增加至162.69±16.46N,差异有显著性(P<0.05);上终板前侧最大压缩力为87.30±6.42N,后侧为89.25±14.30N,下终板前侧最大压缩力107.63±4.84N,后侧最大压缩力109.82±18.66N,差异均无显著性(P>0.05)。(3)L3/4、L4/5上下终板的最大压缩力的差异均有显著性(P<0.05),余间隙差异无显著性。结论:L1～S1上终板强度逐渐增大;L1～L4下终板强度逐渐增大,L4～L5减小;腰骶椎上、下终板强度从中央至外周逐渐增大,前、后侧无差异;L3/4、L4/5间隙上位椎体下终板强度大于下位椎体上终板。

Objective：To determine the distribution of the biomechanical properties of the lumbosacral endplates.Method：Compression tests with electronic experimental instrument （Model CSS-2205） were performed with 49 standardized test sites in 55 bony endplates of intact adult cadaveric vertebrae （L1-S1） using a 1.5mm-diameter and plane indenter with a test rate of 12mm/min,datas were analyzed statistically.Result：The failure load varied significantly among the lumbosacral level （superior endplates,L1 68.81±8.12N-S1 120.41± 34.33N ,P〈0.05 ;inferior endplates ：L1 78.66±5,57N -L4 120,44±29.27 -L5 106,65 ±16.10N ,P〈0.05）,The failure load of the lumbosacral endplates varied significantly between the center of bone and the margin（superior endplates 65.02±6.40N-110.61±10.63N ,P〈0.05 ;inferior endplates 68.09±9,43N -162,69±16A6N ,P〈0.05）,There was no significantly difference in the failure load between the anterior and posterior regions of the lumbosacral endplates （the anterior regions of superior endplates 87.30±6.42N,posterior regions 89.25±14.30N, P〉0.05;the anterior regions of inferior endplates 107.63±4.84N,posterior regions 109.82±18.66N,P〉0.05）.The failure load varied significantly between L3/4 and L4/5 （L3 inferior endplate 104.07±11.70N,L4 superior endplate 77.50±7.54N,P〈0.05;L4 inferior endplate 120.44±29.27N,L5 superior endplate 81.04±8.32N,P〈0.05）. Conchlsion：The strength of the lumbosacral superior endplate increases from L1 to S1.The strength of the inferior endplate increases from L1 to IA then decreases from L4 to L5.The strength of the lumbosacral endplates increases from the center of bone to the margin.No difference is noted in the strength between the anterior and posterior regions of the lumbosacral endplates.The strength of the lumbosacral inferior endplates is significantly higher than that of the lumbar superior endplates between L3/4 and L4/5.