腰椎间盘突出患者腰椎CT三维重建影像的解剖学测量及其在单边双通道内镜手术中的临床意义

目的 探讨腰椎间盘突出症患者腰椎CT三维重建影像解剖学特点及其在单边双通道内镜手术中的意义。方法 横断面调查研究。纳入安徽医科大学第二附属医院骨科2019年1月—2020年6月收治的腰椎间盘突出症的患者50例,其中男32例、女18例,年龄23~69（64.1±13.4）岁。病变节段：L_2/3 1例,L_4/5 18例,L₅/S₁ 23例,L_3/4合并L_4/5 1例,L_4/5合并L₅/S₁ 6例。均采用单边双通道内镜辅助下腰椎间盘突出髓核摘除术治疗。术前患者均行腰椎CT扫描及三维容积重建,观察患者腰椎整体形态结构,使用放射工作站软件测量两侧椎板夹角、椎板宽度、关节突关节矢状化程度以及椎板下移程度,并进行腰椎节段间及侧别间比较。结果 （1）棘突与两侧椎板呈“人”字形平滑连接,两侧椎板向两侧弧形展开。两侧椎板夹角自L₃至L₅逐渐增大,分别为70°±11°、78°±12°和92°±13°,差异有统计学意义（F=42.25,P<0.001）。（2）椎板下缘向两侧延伸,椎板宽度自L₃至L₅逐渐增宽,左侧分别为（14.0±2.4）、（15.7±2.6）和（18.7±2.8）mm,右侧分别为（14.4±2.4）、（16.4±2.3）和（19.2±2.8）mm,各节段椎板宽度右侧均大于左侧,差异均有统计学意义（t=2.13、4.00、2.78,P值均<0.05）。（3）椎板末端逐渐增宽膨大成关节面,关节面L_3/4~L₅/S₁逐渐由矢状化转变为冠状化,左侧分别为60°±10°、50°±9°和42°±11°,右侧分别为58°±11°、48°±10°和40°±13°。同一节段左右两侧对比,在L_3/4差异有统计学意义（t=2.92,P=0.005）,在L_4/5及L₅/S₁差异均无统计学意义（t=1.29、1.79,P值均>0.05）。（4）椎板下移程度自L₃至L₅逐渐减小,分别为（6.8±2.1）、（5.1±2.3）和（2.4±2.3）mm,差异有统计学意义（F=50.39,P<0.001）。结论 腰椎间盘突出症患者从L₃到L₅,两侧椎板夹角逐渐增大、椎板宽度逐渐增大、关节突关节逐渐由矢状化转变为冠状化、椎板下移程度逐渐减小。了解腰椎解剖的节段性变化有助于单边双通道内镜手术的顺利进行、椎板去除范围的确定、对关节突关节的保护以及椎间盘位置的确定。

CT three-dimensional reconstruction and measurement of lumbar spine in patients with lumbar disc herniation and its clinical significance in unilateral biportal endoscopic technique

Objective This study aims to explore the anatomical features of lumbar CT three-dimensional images in patients with lumbar disc herniation and its significance in unilateral biportal endoscopic technique. Methods A cross-sectional design was used. A total of 50 patients with lumbar disc herniation were selected from the Department of Orthopedics, the Second Affiliated Hospital of Anhui Medical University from January 2019 to June 2020. The participants included 32 males and 18 females aged 23 to 69 (64.1±13.4) years and had the following segments of lesions: L_2/3 1, L_4/5 18, L₅/S₁ 23, L_3/4 with L_4/5 1, and L_4/5 with L₅/S₁ 6. All patients underwent lumbar disc nucleus pulposus removal by unilateral biportal endoscopic technique. All patients underwent CT scanning and volume rendering of lumbar vertebrae before operation. The overall morphological structure of lumbar vertebrae was observed by CT volume rendering. The angle between lamina, the width of lamina, the sagittal degree of facet joint, and the degree of downward movement of lamina were measured in radiation workstation software and compared among different segments and laterals. Results (1) The spinous process was smoothly linked with the bilateral vertebral plates in a herringbone shape, and the bilateral vertebral plates arc out to both sides. The included angles from L₃ to L₅ between the two sides of the lamina gradually increased, with values of 70°±11°, 78°±12°, and 92°±13°, respectively. No statistically significant difference was found between L₃ and L₅ (F=42.25, P<0.001). (2) The lower edge of the lamina extended to both sides, and the width of the lamina gradually widens from L₃ to L₅. The widths of the left side were (14.0±2.4), (15.7±2.6), and (18.7±2.8) mm, respectively, and those of the right side were (14.4±2.4), (16.4±2.3), and (19.2±2.8) mm, respectively. The width of the right side of each segment was larger than that of the left side, and the difference was statistically significant (t=2.13, 4.00, 2.78, all P values <0.05). (3) The end of the lamina gradually widened and expanded to form an articular surface, and its L_3/4-L₅/S₁ gradually changed from sagittal to coronal. The left sides were 60°±10°, 50°±9°, and 42°±11°, respectively, and the right sides were 58°±11°, 48°±10°, and 40°±13°, respectively. Statistically significant difference was found between the left and right sides of the same segment compared with L_3/4 (t=2.92, P=0.005), but no statistically significant difference was detected between the left and right sides of L_4/5 and L₅/S₁ (t=1.29, 1.79, all P values >0.05). (4) The degree of downward movement of lamina gradually decreased from L₃ to L₅, and the difference was statistically significant (F=50.39, P<0.001), which were (6.8±2.1), (5.1±2.3), and (2.4±2.3) mm, respectively. Conclusion From L₃ to L₅, the angle between the two sides of the lamina gradually increases, the lateral width of the lamina gradually increases, the facet joint gradually changes from sagittal to coronal, and the descending degree of the lamina gradually decreases in patients with lumbar disc herniation. Understanding the segmental changes in the anatomy of the lumbar spine can help with smooth operation, determination of the extent of lamina removal, protection of facet joints, and identify the location of the disc.