腰椎间盘突出症的骨结构差异及其对MED的指导意义

Bony variations of vertebral body in the lumbar spine among patients of lumbar disc herniation and its significance on microendoscopic discectomy

目的研究腰椎间盘突出症患者的腰椎后部骨结构解剖因素,分析其对显微内窥镜椎间盘切除术(microendoscopicdiscectomy,MED)的影响,及可能引起的危险和并发症。方法研究采用MED治疗的160例腰椎间盘突出症患者的CT扫描图像,对其突出节段的棘突成角、棘突偏向、椎板长、椎板厚、椎板成角、小关节纵轴长及小关节间距等解剖参数进行测量记录,分析各参数间相关性及其与MED术中情况的关系。结果椎板倾斜、棘突畸形偏向手术侧、椎小关节发育性或增生性内聚、椎板过厚、椎板相对椎间盘水平低或位置过低、椎板过短、椎管最小内径和椎管侧壁过深等是影响MED的解剖因素。同一MED病例L4,5节段比L5S1难度增加很多。研究表明椎板长度大于18mm、椎板角大于120°和椎管侧壁深度小于10mm的病例,行MED手术会非常容易。椎板长度小于12mm、椎板角小于100°和椎管侧壁深度大于14mm的患者行MED术会非常困难和危险,如有上述解剖变异和畸形情况,则不应采用MED治疗;介于两者之间的病例应根据具体情况慎重选择。结论因为器械因素,很多病例不适合MED手术。对切开手术影响不大的腰椎后部解剖结构变异,对MED非常重要,应该成为选择MED的一个手术指征。术前测量腰椎后部解剖数据,选择适合病例行MED,可预防并发症、提高手术的易行性和安全性。

Objective To evaluate the bony variations in lumbar vertebral body among the patients with lnmbar disc herniation and determine its significance to microendoscopic discectomy （MED）. Methods The CT images of 160 patients who underwent MED for lumbar disc herniation were reviewed. Measurements of vertebral bony dimensions related to surgical procedure were recorded, which included the angle of spinal process and lamina, spinal process direction, length, thickness and angle of the laminar, facet depth, spinal process width, and the distance between facets and lamina. The relationship between the bony variations and clinical outcome was analyzed. Results The majority of anatomic parameters are greater in male patients and in L5S1 segment than those in female and in L4.5 （P 〈 0.05）. There were 55% of patients with deviated spinal process. Spinal process deviating to the side of involved disc, laminar inclining, degenerative or heteroplastic changes of facets, lamina overhang, laminar length or thickness, interfacet distance may affect MED procedure and clinical outcome. We found in our group that the MED procedure would be ersier if the length of laminar larger than 18 mm, laminar angle over 120 degree and the depth of the side wall of the spinal canal less than l0 mm. While if the length of laminar shorter than 12 mm, laminar angle less than 100 degree and the depth of the side wall of the spinal canal overl2 mm the procedure were indifficalty. Conclusion Bony variations had significant effects on the procedure of MED and surgeon should pay special attention during pre-operation preparation. Safe and effective MED may benefit from comprehensive understanding of the bony variation in each patient.