腰椎经皮内镜下不同部位关节突成形对相关节段活动度的影响

Effects of Facet Joint Arthroplasty at Different Positions under Lumbar Percutaneous Endoscopy on Range of Motion of Vertebral Bodies

目的利用三维有限元法评估腰椎经皮内镜下不同的关节突成形部位对椎体活动度(range of motion, ROM)的影响。方法建立正常L3～5三维有限元模型,模拟腰椎经皮内镜技术分别在L5上关节突"尖部"或"基底部"做直径0.75 cm圆柱状骨切除以模拟椎间孔成形,从而获得正常L3～5模型、关节突尖部成形模型和关节突基底部成形模型。给予特定加载条件,比较3种模型在前屈、后伸、左右侧曲、左右旋转工况下L3～4、L4～5节段ROM变化情况。结果 L5上关节突尖部成形后,在后伸、左右侧屈、左右旋转状态下L4～5节段ROM均较正常明显增大,以左旋最为明显;L5上关节突基底部成形后,在左右旋转状态下L4～5节段ROM较正常稍微增大。L5上关节突尖部、基底部成形后在6种不同运动状态下临近节段L3/4的ROM均无明显变化。结论腰椎经皮内镜技术下,L5上关节突尖部成形较关节突基底部成形对L4～5节段ROM影响较大。L5上关节突成型对临近节段L3～4的ROM无明显影响。

Objective To evaluate the influence of facet joint arthroplasty at different positions under lumbar percutaneous endoscopy on range of motion(ROM)of vertebral bodies by using the three-dimensional(3D)finite element method.Methods The 3D finite element model of normal L3-5 segment was established,and lumbar percutaneous endoscopy was simulated by doing cylindrical excision of bone with diameter of 7.5 mm on the tip or basement of L5 facet joint,so as to obtain normal lumbar vertebra model,L5 facet joint model with shaped tip,L5 facet joint model with shaped basement,respectively.Given specific loading conditions,the ROMs of adjacent vertebral bodies for the 3 models under flexion,extension,left and right lateral flexion,left and right rotation were compared.Results When L5 facet joint tip was shaped,the ROMs of L4-5 under extension,left lateral flexion,right lateral flexion,left rotation and right rotation were obviously larger than those of the normal model,especially under left rotation.When the L5 facet joint basement was shaped,the ROMS of L4-5 under left and right rotation increased slightly compared with those of the normal model.However,the ROMs of L3-4 for both tip-shaped and basement-shaped L5 facet joint model showed no obvious changes under six different motions.Conclusions The influence of L5 facet joint with shaped tip on ROMs of L4-5 was relatively larger than that of L5 facet joint with shaped basement under lumber percutaneous endoscopy.There was no significant effect on the ROMs of L3-4 with L5 facet joint arthroplasty.