L4/5极外侧腰椎间盘突出症内镜治疗的影像测量△

Imaging measurements for endoscopic treatment of L4 5 far lateral lumbar disc herniation

摘要:

[目的] 在三维模型确定与镜下观测一致的骨性标志点，测量辅助单孔分体内镜准确定位并安全减压L4 出口神经根的参数。[方法] 构建34 例L4/5 单侧极外侧腰椎间盘突出症患者腰椎CT 三维模型，以横突根部下缘与峡部外侧缘的交点（in-tersection of the lower margin of the transverse process root with the lateral margin of the isthmus, ITPI） 为骨性标志点，分别在ITPI 所在的矢状面测量相关指标，并进行男女间、健侧与患侧的比较。[结果] L4 出口神经根下缘投影于L4/5 椎间隙之上，健侧占比（4/34, 11.8%） 小于患侧占比（18/34, 52.9%），投影于L4/5 椎间隙之内，健侧占比（30/34, 88.2%） 大于患侧占比（12/34，35.3%）。分别测量ITPI 至L4 出口神经根上缘的垂直距离、L4 出口神经根下缘的垂直距离、L4 出口神经根后缘的前后水平距离、L4 下终板的垂直距离、L5 上终板的垂直距离、L4 椎弓根下缘的垂直距离；ITPI 分别至L4 下终板最外侧缘的左右水平距离以及其所在矢状面上L4 出口神经根上缘的垂直距离、L4 出口神经根下缘的垂直距离、L4 下终板的垂直距离、L5 上终板的垂直距离；ITPI 分别至L4 椎弓根内侧壁的左右水平距离、硬脊膜外侧缘的左右水平距离，以上指标男女间、健患侧之间差异均无统计学意义（P＞0.05）。各测量指标与年龄、BMI 均无显著相关性（P＞0.05）。[结论] 以L4 横突根部下缘与峡部外侧缘交点作为骨性标志点，无需向上探查，只需向外、向下磨除部分骨质即可显露并安全减压L4 出口神经根。

Abstract:

[Objective] In three-dimensional models with the bony landmarks consistent with the endoscopic observation, the parame-ters related to L4 outlet nerve root accurately located and safely decompressed was measured for assistance of one-hole split endoscope.[Methods] On the 3D lumbar models of 34 patients with L4/5 unilateral far lateral lumbar disc herniation constructed based on CT, the param-eters in the sagittal plane according to the intersection of the lower margin of the L4 transverse process root with the lateral margin of the isth-mus (ITPI) were measured, including the vertical distance from the ITPI to the upper margin of L4 outlet nerve root (UMNR-L4), the verticaldistance of the lower margin of L4 outlet nerve root (LMNR-L4), the anteroposterior horizontal distance of the posterior margin of L4 outletnerve root (PMNR-L4), the vertical distance of the L4 inferior endplate (IEP-L4), the vertical distance of the L5 upper endplate (UEP-L5), ver-tical distance of the pedicle lower margin of L4 pedicle (LMP-L4), and so on. The data were compared between two genders and two sides.[Results] In term of the lower margin of L4 outlet nerve root projected above the L4/5 intervertebral space, the healthy side was smaller thanthat of the affected side [4/34 (11.8%) vs 18/34 (52.9%)]; while the proportion of healthy side was larger than that of the affected side [30/34(88.2%) vs 12/34 (35.3%)] when projected within the L4/5 intervertebral space. There were no significant differences between two genders andtwo sides in terms of the vertical distance between ITPI and the upper edge of L4 outlet nerve root, the vertical distance between lower edge ofL4 outlet nerve root, the horizontal distance between anterior and posterior edge of L4 outlet nerve root, the vertical distance between lowerend plate of L4, the vertical distance between upper end plate of L5 and the vertical distance between lower edge of L4 pedicle, the left and right horizontal distance of ITPI to the outermost edge of the L4 inferior endplate, the vertical distance of the upper edge of the L4 outlet nerveroot on the sagittal plane, the vertical distance of the lower edge of the L4 outlet nerve root, the vertical distance of the L4 inferior endplate,the vertical distance of the L5 upper endplate located in ITPI, and the left and right horizontal distance of the medial wall of the L4 pedicleand the left and right horizontal distance of the lateral border of the dura (P＞0.05). There were no significant correlations among the mea-sured parameters to age and BMI (P＞0.05). [Conclusion] As the intersection of the lower margin of the L4 transverse process root with the lat-eral margin of the isthmus was used as the bony landmark, there was no need to explore upward, but only part of the bone is removed outwardand downward to expose and decompress the L4 outlet nerve root safely.