【摘要】 目的 探讨利用术前CT多平面重建（MPR）图像上钉道设计与术中确定枢椎峡部中心，指导后路寰枢经关节螺钉内固定徒手置钉的价值。 方法 选取成人头颈尸体标本9具，及寰枢关节不稳患者5例，螺旋CT扫描，取后路寰枢经关节螺钉内固定的理想钉道（经枢椎峡部中心点）所在平面重建并设计个体化钉道，确定安全的置钉范围。参考术前钉道设计与术中确定枢椎峡部中心，徒手行后路寰枢经关节螺钉固定。术后对实际钉道CT多平面重建，分析徒手实际置钉情况。 结果 后路寰枢经关节螺钉固定共28侧，术中徒手操作顺利，无重要血管神经损伤。手术实际钉道均在术前设计钉道的安全范围内。5例患者寰枢椎间术后较术前存在相对位移变化。 结论 根据螺旋CT MPR图像设计的个体化后路寰枢经关节螺钉内固定钉道，结合术中枢椎峡部中心显露，可指导临床安全地徒手置钉。【Abstract】 Objective To explore the clinical value of the free-hand technique on making the screw path of posterior atlantoaxial transarticular screw fixation, which guided in accordance with the preoperative design of the screw trajectory in spiral CT multilevel reconstruction (MPR) imaging and intra-operative exposure of the center of C2 isthmus. Methods The cervical spine segments of 9 human cadavers and 5 patients with atlantoaxial instability were scanned with spiral computed tomography. Then the CT MPR images of ideal screw trajectory of posterior atalanto-axial transarticular screw reconstructed through the central point of C2 isthmus were used for plotting individual safe screw trajectory. According to preoperative designing of the individual screw trajectory and intraoperative exposure of the center of C2 isthmus, free-hand operation made the transarticular screw path of posterior atlantoaxial screw fixation. Postoperative CT MPR image was used to analyze the actual screw trajectory in atlantoaxial complex, as well. Results The transarticular screws were inserted atlantoaxial joints in 28 sides. The free-hand operation of screw placement was successful, and no screw misplacement or major neurovascular injury was found. There was relative displacement between the atlas and axial vertebrae in 5 patients. Conclusion The free-hand technique of posterior atlantoaxial transarticular screw placement is reliable and safe which refers the preoperative individual screw trajectory designed by CT MPR image and intraoperative exposure of the center of C2 isthmus.