经皮激光椎间盘减压术对山羊腰椎稳定性影响的生物力学测试

Effect of percutaneous laser disc decompression on normal goat lumbar biomechanical stability

目的:观察经皮激光椎间盘减压术对正常山羊腰椎间盘髓核汽化后腰椎稳定性的影响。方法:选取正常新鲜山羊腰椎标本40具,截取L1～L6节段,剔除肌肉组织,两端用牙托粉固定。随机分为A、B、C、D、E共5组,每组8个标本。A组为空白对照组,不对椎间盘进行处理;B组L3/4(单节段组),C组L3/4和L4/5(相邻双节段组),D组L2/3和L4/5(间隔双节段组),E组L2/3、L3/4和L4/5(3节段组)椎间盘分别行激光汽化,每个椎间盘总能量为500J。所有标本处理后在生物力学测定仪上测定轴向拉伸、轴向加压、前方加压、后方加压、左侧加压及右侧加压试验,分别记录负荷加载力为20N、40N、60N、80N和100N时标本的位移。结果:在不同负荷下,各组标本在相同加载方式的位移量均随负荷增大而增加;在相同负荷相同加载方式时,A组与B、C、D、E组标本位移量比较均无统计学意义(P>0.05),B、C、D、E组标本位移量相互比较均无统计学意义(P>0.05)。结论:经皮激光椎间盘减压术汽化3个节段及3个节段以内的椎间盘组织对山羊腰椎的稳定性没有明显影响。

Objective：To observe the effects of percntaneous laser disc decompression （PLDD） on normal goat lumbar biomechanical stability.Method：The vertebral segments from L1 to L6 were selected from 40 normal goat lumbar specimens and,after removing of surrouding muscle tissue,both ends of each segment were fixed with dental base acrylic resin powder.Specimens were then randomly divided into 5 groups,8 specimens for each.Group A is the control group,none of the discs was involved by PLDD,Group B,L2/3 （the single-seg- ment）,group C,L3/4 and L4/5（close bi-segment）,group D L2/3 and L4/5（seperated bi-segrnent） and group E L2/3,L3/4 and L4/5 （tri-segment） were treated by PLDD respectively.The laser energy applied in each disc was 5ooJ.Axial tension-compression,anterior-posterior compression and left-right compression were applied for all specimens.Displacement of the specimen was recorded when loading forces given as 20N,40N,60N,80N and 10ON.Result：Under different loading,the displacement of the specimens in each group increased with increasing of the loading force while the loading method was the same.Under the same load and same loading metnod,there was no statistics difference in displacement of specimen between group A and group B,C,D,E respectively （P〉0.O5）.The displacement of specimen among group B,C,D and E displayed no statistically dif- ferent （P〉0.05）.Conclusion：Biomechenical stability of the goat lumbar vertebra is not affected by PLDD when vaporization of the nucleus pulposus within three segments.