前路经枕寰枢关节螺钉内固定的临床解剖学研究

Clinical anatomical study of anterior occiput to axis screw fixation

[目的]探讨前路经枕寰枢关节螺钉的临床应用解剖学依据。[方法]取30具国人干燥枕颈部标本,测量与经枕寰枢关节螺钉内固定术相关的解剖径线及钉道参数;并以此类数据为依据,在所测量的干燥标本上模拟行经枕寰枢关节螺钉内固定术,经X线摄片检查内固定位置并测量钉道实际角度。[结果]前路经枕寰枢关节螺钉内固定的钉道在矢状面上呈后倾,在冠状面上呈外倾。左右两侧钉道角度大小差异无统计学差异,理想外倾角为(18.15±3.70)°,理想后倾角为(24.20±4.91)°,理想钉道长度为(34.45±2.9)mm;模拟行内固定验证,术后影像学及直视下检查结果显示,螺钉钉道均经过枕寰枢关节,角度均在此范围内,无穿出骨质者。[结论]采用前路经枕寰枢关节螺钉行枕颈融合内固定在解剖上是可行的。

[Objective]To explore the anatomical basis for clinical applications of occipitocervical fusion by anterior transarticular screw fixation from the axis to the occiput. [Methods]The correlated anatomic linear and the screw rajectory parameters of anterior transarticular screw fixation from the axis to the occiput were observed and measured on thirty adult human bone specimens.According to the data measured,anterior occiput-to-axis screw fixation was performed on the dry craniovertebral junction specimens.Roentgen rays were examined to study the positions of screws and to measure the angle of the screw trajectory. [Results]The occiput to axis transarticular screw trajectory was placed posteriorly tilting in sagittal plane and lateral tilting in coronary plane.The screw tip was located in the posterolateral third of the occipital condyle.There was no significant difference（P〈0.05） between leftside and rightside.The ideally placed angle of the screw was direct（18.15±3.70） °laterally in the coronal plane and（24.20±4.91） °posteriorly in the sagittal plane.The ideal length of the trajectory was（34.45±2.9） mm.Imageological examination and direct vision demonstrated that anterior occiput to axis screw fixation according the above results ensured insertion of the trajectory passing through the atlanto-occipital articulation and the atlanto-axial articulation without piercing the bones. [Conclusion]From the anatomical standpoint,the technique of anterior fixation from the atlas to the occiput is feasible.