基于CT影像的经皮椎间孔镜腰椎体间融合手术入路的解剖学研究

目的 探讨在椎间孔区域的神经根与邻近组织的CT影像学的解剖学关系,为经皮椎间孔镜腰椎融合手术的应用提供参考。方法 回顾性分析2017年1—10月天津市天津医院因腰背部不适行腰椎CT检查的110例患者CT影像资料。110例患者均行螺旋CT平扫,图像经AW46图像工作站后处理,行三维重建及测量。选取L_2/3~L₅/S₁节段椎间盘三维重建旋转冠状面可见神经根走行的层面以及相应节段椎间盘横断面图像,对椎间盘上、下缘两个层面出口神经根到脊髓硬膜囊的最短距离(Js、Ji),出口神经根到椎弓根内、中、外侧的距离(Pa、Pb、Pc),以及出口神经根到骨性关节突和关节突关节面的最短距离(Gs、Gi)进行测量分析。结果 L_2/3节段~L₅/S₁节段,Js和Ji数值均逐渐增大,且Ji均>Js,其中L_2/3节段Js的数值最小为(6.71±2.10)mm,L₅/S₁节段Ji的数值最大为(22.05±3.96)mm;每一节段出口神经根-椎弓根的距离从内侧向外侧逐渐减小,Pb及Pc值逐渐减小,以L₅/S₁节段为最小(3.86±1.93)mm;下缘层面的Gi均大于上缘层面的Gs。结论 在L_3/4以上节段置入宽度为10 mm的椎间融合器较为困难;术中镜下磨除部分或全部上关节突,可以扩大安全区域,避免损伤神经及周围重要结构,利于融合器的置入。

CT-based analysis of the approach of percutaneous endoscopic lumbar interbody fusion

Objective To analyze the relationship between the nerve root and its surroundings to their corresponding intervertebral disc for percutaneous endoscopic lumbar interbody fusion approaches. Methods A retrospective study in Tianjin Hospital from January 2017 to October 2017 was carried out. The CT images were obtained from patients presented with low back pain. One hundred and ten CT data were collected and the images were processed by graphic workstation(AW46) for measuring. The CT analysis was done bilaterally from L_2/3 to L₅/S₁. On the vertical plane of long-axis of pedicle which nerve root was visible, nerve root- dural sac distances were analyzed at the superior and inferior margin of the disc(Js, Ji). Also, nerve root-pedicle distances were at the medial, middle and lateral borders of the pedicle(Pa, Pb, Pc). On transverse plane, nerve root-articular process and nerve root-articular process joint surface shortest distance were analyzed at the superior and inferior margin of the disc(Gs, Gi)respectively. Results From L_2/3 to L₅/S₁,the distances of nerve root- dural sac were larger at inferior margin of the disc. The smallest Js was measured at the superior margin of L_2/3 (6.71±2.10)mm and the largest Ji was measured at the inferior margin of L₅/S₁(22.05±3.96)mm. And from L_2/3 to L₅/S₁, each segment of vertebral nerve root-pedicle distances was gradually reduced from medial to lateral, as well as Pb and Pc. The smallest distance was Pc of L₅/S₁ (3.86± 1.93) mm. The shortest distance of nerve root-articular process joint surface at inferior margin of disc was larger than the distance of nerve root-articular process at superior margin of the disc from L_2/3 to L₅/S₁. Conclusions It is more difficult to implant a cage with a width of 10 mm above L_3/4 segment. By removing the parts of superior articular process, it could expand the safe working area, and avoid hurting nerve or other structures when implanting a cage.