Objective:

To investigate the relationships between the bony structures, nerve, and indentations of ligamentum flavum of the upper lumbar spine by using CT three-dimensional reconstruction technique, in order to guide the unilateral biportal endoscopy (UBE) technique via contralateral approach in the treatment of upper lumbar disc herniation (ULDH).

Methods:

Twenty-one ULDH patients who were admitted between June 2019 and July 2021 and met the selection criteria were selected as the research subjects. There were 12 males and 9 females with an average age of 62.1 years (range, 55-72 years). The disease duration was 1-12 years (mean, 5.7 years). There was 1 case of L _{1, 2}, 4 cases of L _{2, 3}, and 16 cases of L _{3, 4}. The CT myelography data of T ₁₂-S ₃ segment was saved in DICOM format and imported into Mimics21.0 software for three-dimensional reconstruction. The relationship between the intersection (point Q) of spinous process and the inferior margin of lamina, the indentation of superior margin of ligamentum flavum, the inferior margin of nerve root origin, intervertebral space, and foramen were observed. The Mimics21.0 software was used to create a 3-mm-diameter cylinder to simulate the UBE channel and measure its abduction angle (∠b1), as well as measure the following lumbar vertebra-related indicators: in L _1,2-L _3,4 segments, the vertical distance from the point Q to the inferior margin of the contralateral lumbar pedicle of the same lumbar vertebra (a1), the superior margin of the contralateral pedicle of the lower lumbar vertebra (a2), the lower endplate of the same lumbar vertebra (a3), the upper endplate of the lower lumbar vertebra (a4); the vertical distance from the lower endplate of lumbar vertebra to the inferior margin of the lumbar pedicle (c1), the vertical distance from the upper endplate of the lower lumbar vertebra to the superior margin of the lumbar pedicle (c2); the vertical distance from the inferior margin of the nerve root origin to the superior margin (d1) and the inferior margin (d2) of the lumbar pedicle, respectively; the vertical distance from the intersection (point P) of the indentation of superior margin of ligamentum flavum and the medial margin of the lumbar pedicle to the superior margin (e1) and the inferior margin (e2) of the lumbar pedicle, respectively; the horizontal distance from the lateral margin of the dural mater (f1) and the narrowest part of the lumbar isthmus (f2) to the facet joint space, respectively. Thirteen of the patients included in the study chose the UBE surgery via contralateral approach. There were 8 males and 5 females with an average age of 63.3 years (range, 55-71 years). The disease duration was 2-12 years, with an average of 6.2 years. There were 3 cases of L _{2, 3} and 10 cases of L _{3, 4}. The perioperative complications and surgical decompression were recorded. And the effectiveness were evaluated by visual analogue scale (VAS) score, Oswestry disability index (ODI), and short form-36 health survey (SF-36) score.

Results:

The imaging results showed that there was no significant difference in a1, a3, a4, e1, e2, f1, and f2 between segments ( P>0.05), and there were significant differences ( P<0.05) in a2 and c2 between L _{1, 2} and L _{3, 4} segments, in ∠b1 and d2 between L _{1, 2}, L _{2, 3} segments and L _{3, 4} segments, and in c1 and d1 between L _{1, 2} and L _{2, 3}, L _{3, 4} segments. The 87.30% (110/126) of point Q of L _{1, 2}-L _{3, 4} segments corresponded to the inferior articular process, and 78.57% (99/126) of the lower endplate corresponded to the level of the isthmus. All 13 patients completed the UBE surgery via contralateral approach, and none were converted to open surgery. All patients were followed up 12-17 months (mean, 14.6) months. The VAS score of low back pain and leg pain, ODI, and SF-36 score at 6 and 12 months after operation significantly improved when compared with those before operation ( P<0.05), and further improved at 12 months after operation when compared with 6 months after operation ( P<0.05). The imaging review results showed that the herniated disc was removed and the dura mater was decompressed adequately.

Conclusion:

The point Q, the superior margin of ligamentum flavum, and lumbar pedicle can be used as the markers for the treatment of ULBD with UBE surgery via contralateral approach, making the procedure safer, more precise, and more effective.

目的:

通过CT三维重建技术，观测上腰椎骨性结构、神经、黄韧带压迹等位置关系，指导单侧双通道脊柱内镜（unilateral biportal endoscopy，UBE）技术对侧入路治疗上腰椎椎间盘突出症（upper lumbar disc herniation，ULDH）。.

方法:

以2019年6月—2021年7月收治且符合选择标准的21例ULDH患者作为研究对象，其中男12例，女9例；年龄55～72岁，平均62.1岁。病程1～12年，平均5.7年。病变节段：L _1、2 1例，L _2、3 4例，L _3、4 16例。将患者T ₁₂～S ₃节段CT脊髓造影数据导入Mimics21.0软件行腰椎三维重建，观察上腰椎节段椎体棘突侧方与椎板下缘交点（Q点）、黄韧带上缘压迹线、神经根起点下缘、椎间孔及椎间隙等组织结构毗邻关系。应用Mimics21.0软件建立直径3 mm圆柱体模拟UBE手术路径并测量其外展角（∠b1），以及测量以下腰椎相关指标：L _1、2～L _3、4节段Q点至同节段椎体对侧椎弓根下缘、下位椎体对侧椎弓根上缘、同节段椎体下终板、下位椎体上终板的垂直距离（分别记为a1、a2、a3、a4）；椎体下终板至同节段椎弓根下缘垂直距离，椎弓根上缘至下位椎体上终板垂直距离（分别记为c1、c2）；神经根起点下缘分别至同节段椎弓根上缘、下缘垂直距离（分别记为d1、d2）；黄韧带上缘压迹线外侧部与椎弓根内侧缘交点（P点），分别至同节段椎弓根上、下缘垂直距离（分别记为e1、e2）；关节突关节间隙、椎体峡部最狭窄处外侧缘分别至硬脊膜外侧缘水平距离（分别记为f1、f2）。研究纳入患者中13例选择UBE对侧入路手术治疗。男8例，女5例；年龄55～71岁，平均63.3岁。病程2～12年，平均6.2年。病变节段：L _2、3 3例，L _3、4 10例。记录围术期并发症，影像学复查手术减压情况，采用疼痛视觉模拟评分（VAS）、Oswestry功能障碍指数（ODI）、简明健康调查量表（SF-36量表）评分评价临床疗效。.

结果:

影像学观测显示，各节段a1、a3、a4、e1、e2、f1、f2比较差异均无统计学意义（ P>0.05），a2、c2仅L _1、2、L _3、4节段比较差异有统计学意义（ P<0.05），∠b1、d2仅L _3、4节段与L _1、2、L _2、3节段比较差异有统计学意义（ P<0.05），c1、d1仅L _1、2与L _2、3、L _3、4节段比较差异有统计学意义（ P<0.05）。L _1、2～L _3、4节段Q点87.30%（110/126）对应下关节突水平，椎体下终板78.57%（99/126）对应椎体峡部水平。临床应用13例患者均完成UBE对侧入路手术，无转为开放手术。术中1例发生硬脊膜撕裂。患者均获随访，随访时间12～17个月，平均14.6个月。术后6、12个月腰痛及腿痛VAS评分、ODI、SF-36量表评分均较术前改善（ P<0.05），术后12个月较6个月进一步改善（ P<0.05）。影像学复查示去除突出椎间盘后硬脊膜得到充分减压，椎管无明显狭窄。.

结论:

UBE对侧入路治疗ULBD可以Q点、黄韧带上缘、椎弓根作为手术标志，定位椎间盘及神经根起点下缘，使手术更安全、精准、有效。.