腰椎L4和L5侧路单cage椎间融合术的生物力学与临床应用研究

目的探讨腰椎L4和L5侧路单cage椎间融合术的生物力学与临床应用的前景。方法（1）通过一名健康成年男性腰椎CT扫描，三维有限元单元划分原则进行腰椎三维有限元分析。（2）取新鲜小牛腰椎的L4和L5运动节段标本，随机分组并模拟两种手术方式。第一组右侧椎板开窗经侧方置入一枚椎间融合器。第二组右侧半椎板及上、下小关节切除减压经后方斜向置入一枚椎间融合器，实测施加于小牛腰椎进行各工况载荷时相关位点的相对位移变化，并进行统计学分析。（3）收集30例患者并进行腰椎L4和L5侧路单cage椎间融合术，用日本矫形外科学会（JOA）评分标准判断手术疗效。结果三维有限元模型试验结果，在腰椎模型的屈曲、后伸、右侧弯及旋转刚度上侧路均较后路为好，纵向压缩及左侧弯规律不明显。小牛腰椎模型，脊柱在屈、伸、左右侧弯活动中侧路模型均优于后路且差异具有统计学意义，纵向压缩差异无统计学意义。临床应用手术有效率100％，腰痛改善率90．0％，未出现严重并发症。结论生物力学及临床应用研究表明，侧路植入单枚融合器效果比后路更具优势，手术方式安全有效，值得推广。

Biomechanical and clinical research of lateral lumbar interbody fusion with single cage for the 4th and 5th lumbar spine

Objective To explore the perspective and practicability of the biomechanical and clinical re- search of lateral lumbar interbody fusion with single cage for the 4th and 5th lumbar spine. Methods （ 1 ） The princi- ple of units classification was used to analyze the three-dimensional finife element of lumbar spine established by a health adult man＇ s CT. （2）Samples of L4,5 exercise fragment of a fresh calf were taken, randomly divided into two groups and simulated two kinds of surgical methods. In the first group, right vertebra lamina was windowed and placed a cage by the lateral side of the lumbar spine. In the second group, semi-lamina of vertebra and upper and lower small joints were reseeted for decompression and slantly placed one cage by the proterior side and the relative displacement of the related points was measured. When the samples were exerted working load, data was recorded and statistical analysis was performed. （3）Thrity patients were collected to receive L4,5 lateral lumbar interbody fusion with cage and the operative efficacy was evaluted with JOA evaluation standard. Results In three imensional finite element model, in the stiffness of buckling, extension, right side-bend, rotation, the lateral approach was superior to the posterior. There was no statistically significant difference in the regulation of longitudinal compress and left side- bend between two groups. In the lumbar vertebra model of the calf,the result was also that the lateral approach was superior to the posterior approach in the exercise of buckling, extension, right or left side-bend and rotation, there was dramatically statistical significance. In results of clinical research, the effective rate of operation was 100%, im- provement rate 90% ,none of them had a serious complication. Conclusion From the perspective of biomechanicaland clinical research the effect of implanting lumbar interbody fusion cage from lateral approach is better than from posterior. Surgery is safe and effective, which is worthy of being popularized.