Regev Gilad J, Chen Lina, Dhawan Mallika, Lee Yu Po, Garfin Steven R, Kim Choll W
Department of Orthopaedic Surgery, University of California, San Diego, CA, USA.
Spine (Phila Pa 1976). 2009 May 20;34(12):1330-5. doi: 10.1097/BRS.0b013e3181a029e1.
A morphometric analysis, using magnetic resonance imaging (MRI) studies of the lumbar spine.
To identify the anatomic position of the ventral root and the retroperitoneal vessels in relation to the vertebral body in normally aligned and deformed spines.
The lateral approach to the lumbar spine is a relatively new method for performing interbody fusions. In contrast to the standard open anterior approach with direct vision of the operative field, the lateral approach uses expandable retractors that are positioned under fluoroscopic guidance. Risks of this technique include injury to the exiting nerve root and retroperitoneal vessels.
One hundred lumbar spine MRI studies were reviewed from patients treated for various spinal pathologies. The measured intervertebral segments were divided into 3 groups: group 1 (n = 247), normally aligned vertebrae and disc spaces; group 2 (n = 18), degenerative spondylolisthetic segments; and group 3 (n = 19), segments from the apex of degenerative lumbar scoliosis. Axial MR images were used to measure: the vertebral endplate anterior-posterior (AP) diameter, the overlap between the ventral root and the posterior margin of the vertebra, and the overlap between the retroperitoneal large vessels and the anterior edge of the vertebra.
The overlap between the adjacent neuro-vascular structures and the vertebral body endplate gradually increased from L1-L2 to L4-L5. The maximal overlap, at the L4-L5 level reached 87% resulting in a relatively narrow corridor for performing the operative procedure. Alteration in the anatomic location of the nerve root and the retroperitoneal vessels, in Group 3 (scoliosis) further decreased the safe corridor.
The safe corridor for performing the discectomy and inserting the intervertebral cage narrows from L1-L2 to the L4-L5 level. This corridor is further narrowed with rotatory deformity of the spine. Using the preoperative MRI to assess the relative position of the adjacent neuro-vascular structures in relation to the lower vertebra's endplate at each level is recommended.
一项形态测量分析，采用腰椎的磁共振成像（MRI）研究。
确定在正常排列和变形脊柱中，腹侧神经根和腹膜后血管相对于椎体的解剖位置。
腰椎侧方入路是一种相对较新的椎间融合术式。与可直接观察术野的标准开放前路入路不同，侧方入路使用在透视引导下定位的可扩张牵开器。该技术的风险包括对穿出神经根和腹膜后血管的损伤。
回顾了100例因各种脊柱病变接受治疗患者的腰椎MRI研究。所测量的椎间节段分为3组：第1组（n = 247），椎体和椎间盘间隙正常排列；第2组（n = 18），退变性椎体滑脱节段；第3组（n = 19），退变性腰椎侧弯顶点的节段。利用轴向MR图像测量：椎体终板前后径、腹侧神经根与椎体后缘的重叠情况以及腹膜后大血管与椎体前缘的重叠情况。
相邻神经血管结构与椎体终板之间的重叠从L1-L2至L4-L5逐渐增加。在L4-L5水平重叠最大，达到87%，这导致手术操作的通道相对狭窄。第3组（脊柱侧弯）中神经根和腹膜后血管的解剖位置改变进一步缩小了安全通道。
进行椎间盘切除术和插入椎间融合器的安全通道从L1-L2至L4-L5水平逐渐变窄。脊柱旋转畸形会使该通道进一步变窄。建议术前使用MRI评估每个节段相邻神经血管结构相对于下位椎体终板的相对位置。
