枢椎前路椎弓根螺钉技术的解剖学及生物力学研究

发布时间：2018-11-23 10:43

【摘要】：目的利用Mimics软件设计枢椎前路椎弓根螺钉的理想置钉通路,并测试枢椎前路椎弓根螺钉的生物力学性能,旨在为枢椎前路椎弓根螺钉技术提供解剖学及生物力学依据。方法征集具有正常颈椎结构的成年人,共40名,行颈椎CT扫描。使用Mimics软件导入颈椎CT数据,重建枢椎,根据中心线确定枢椎前路椎弓根螺钉的理想置钉通道。测量理想置钉通道的相关指标:钉道OO’长度、枢椎两侧上关节面内侧缘顶点的连线至进钉点O的距离、枢椎正中矢状面至进钉点O的距离、钉道外倾角、钉道下倾角、椎弓根内中心线上可拟合的最小直径,以及枢椎椎体前方“人”字嵴顶点(由枢椎上关节突下方凹面与椎体外侧缘凹面相交而成的顶点)至进钉点O的距离。获得15个枢椎标本,并通过螺旋CT进行扫描。使用Mimics17转换CT图像,生成三维模型,测量椎弓根长度及进钉角度。根据测量结果,选取合适直径及长度的螺钉。将标本随机分成两组,一组从前路在枢椎左右两侧椎弓根分别置入螺钉;一组分别从枢椎前路及后路椎弓根置入单皮质螺钉。将颈椎置于具有环氧树脂的嵌入盒中,测算其最大轴向拔出力。结果测得枢椎前路椎弓根螺钉理想钉道长度(34.15±2.93)mm;进钉点至枢椎两侧上关节突上缘的连线距离(4.39±0.67)mm;进钉点至枢椎正中矢状面的距离为(3.95±0.44)mm;钉道外倾角α为(30.8±2.79)°;钉道下倾角β为(36.35±3.26)°;枢椎椎弓根内中心线上可拟合的最小直径(7.04±0.87)mm;进钉点至枢椎椎体前方“人”字嵴顶点的距离(1.45±0.19)mm。在生物力学实验,即第二部分实验中,1标本由于椎弓根较为狭窄,无法置入螺钉。最后共纳入14个椎体,其中6个椎体置入螺钉于枢椎前路左右侧椎弓根。其左侧螺钉的最大拔出力(693.53±85.64)N,右侧最大拔出力(732.89±64.78)N。采用配对样本t检验比较左右侧的测定值,两侧差异无统计学意义。两组合并得出最大轴向拔出力为(721.56±83.76)N。共8个椎体从后路及前路枢椎的椎弓根置入单皮质螺钉。前路最大轴向拔出力(718.39±73.68)N,后路(976.95±93.55)N。采取配对样本t检验比较前后路两组的测定值,差异有统计学意义。结论对于大部分患者来说,理论上可以在枢椎前路椎弓根置入螺钉,可使用枢椎椎体前方“人”字嵴顶点作为进钉点,能够避免损伤脊髓、神经根等重要组织。且其生物力学能力较为可靠,可使螺钉松动、拔出等风险下降。但由于枢椎解剖结构个体差异较大,临床上仍需针对每个个体的情况,进行前路椎弓根螺钉的置入。
[Abstract]:Objective to design the ideal screw placement pathway of anterior pedicle screw with Mimics software and to test the biomechanical properties of anterior pedicle screw in order to provide anatomical and biomechanical basis for the technique of anterior pedicle screw. Methods 40 adults with normal cervical vertebra structure were recruited for cervical CT scan. The Mimics software was used to import CT data of cervical vertebrae to reconstruct the axis and to determine the ideal screw placement channel of the anterior pedicle screw according to the center line. The OO' length of the nail path, the distance from the medial edge of the superior articular surface of the axis to the point O, the distance from the median sagittal plane of the axis to the point O, the angle of inclination outside the nail path, the angle of inclination of the nail path, the distance between the median sagittal plane of the axis and the point O of the screw insertion were measured. The minimum diameter that can be fitted on the inner center of the pedicle, and the distance from the vertex of the "human" cristae in front of the axial vertebral body (which is formed by the intersection between the concave surface of the superior articular process of the axis and the concave surface of the lateral edge of the vertebral body) to the point O of entering the screw. Fifteen axial specimens were obtained and scanned by spiral CT. Mimics17 was used to transform CT images to generate three-dimensional models. Pedicle length and screw angle were measured. According to the measurement results, the appropriate diameter and length of screws are selected. The specimens were randomly divided into two groups, one group was treated by anterior approach and the other group was placed with single cortical screw from anterior approach and posterior pedicle respectively. The cervical vertebrae was placed in an embedded box with epoxy resin and its maximum axial pull-out force was calculated. Results the distance between the ideal nail length of anterior pedicle screw (34.15 卤2.93) mm; and the superior edge of superior articular process on both sides of axis was (4.39 卤0.67) mm;. The distance from the point of insertion to the median sagittal plane of the axis was (3.95 卤0.44) mm;, the angle of inclination 伪 was (30.8 卤2.79) 掳, and the angle 尾 was (36.35 卤3.26) 掳. The distance between the minimum diameter of (7.04 卤0.87) mm; entry point and the vertex of the "human" crest in front of the axial vertebra from the fitted minimum diameter on the central line of the pedicle of the axis (1.45 卤0.19) mm. In the second part of the biomechanical experiment, the pedicle of 1 specimen could not be inserted because of the narrow pedicle. A total of 14 vertebrae were included, 6 of which were placed screws on the anterior pedicle of the axial approach. The maximum pull-out force of the left screw was (693.53 卤85.64) N, and that of the right side was (732.89 卤64.78) N. T-test was used to compare the left and right side values, and there was no significant difference between the two sides. The maximum axial pull-out force was (721.56 卤83.76) N. A total of 8 vertebrae were placed with a single cortical screw from the posterior and anterior pedicle of the axial vertebrae. The maximum axial pull-out force was (718.39 卤73.68) N in the anterior approach and (976.95 卤93.55) N in the posterior approach. The t-test of paired samples was used to compare the measured values of the two groups, and the difference was statistically significant. Conclusion for the majority of patients, screws can be inserted into the anterior pedicle of the axial vertebrae in theory, and the apex of the "human" cristae in front of the axial vertebral body can be used as the point of entry, which can avoid the injury of the spinal cord, nerve root and other important tissues. And its biomechanical ability is reliable, can make screw loose, pull out and so on risk reduction. However, due to the large individual differences in the anatomical structure of the axis, the anterior pedicle screw placement is still needed for each individual.
【学位授予单位】：宁波大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R687;R322

【参考文献】