摘要
目的 探讨经后路寰椎椎弓根螺钉固定的可行性。 方法 利用 2 0具颈椎尸体标本 ,模拟经后路寰椎椎弓根螺钉固定。在寰椎后弓后缘表面 ,经枢椎下关节突中心点纵垂线与寰椎后弓上缘下方 3mm水平线的交点作为进钉点 ,按内斜 10度、上斜 5度钻孔 ,经寰椎椎弓根置入直径 3.5 mm的皮质骨螺钉。测量进钉点与寰椎椎弓根中线平面的距离、螺钉最大进钉深度、螺钉内斜角度和螺钉上斜角度等解剖指标 ,观察螺钉是否突破椎弓根和侧块骨皮质 ,以及椎动脉、硬膜、脊髓是否损伤等。 结果 共放置 4 0枚寰椎椎弓根螺钉 ,测得进钉点与寰椎椎弓根中线的平均距离为( 2 .2 0± 0 .4 2 ) mm,螺钉最大进钉深度平均 ( 30 .5 1± 1.5 9) mm,螺钉内斜角度平均 ( 9.70± 0 .6 7)度 ,上斜角 ( 4 .6 0±0 .5 9)度。其中 1枚螺钉因上斜角度过大穿破椎弓根上缘 ,8枚因后弓高度过小而突破椎弓根下缘 ,5枚进钉过深突破寰椎侧块前缘皮质 ,但均未对脊髓和椎动脉造成损伤。 结论 经后路行寰椎椎弓根螺钉固定是安全可行的 。
Objective To assess the possibility of placing the posterior pedicle screw on atlas. Methods Twenty human cadaver specimens were used to insert pedicle screws in atlas, through the posterior arch or the pedicle of C 1 into the lateral mass. The screw entry point was on the posterior surface of C 1 posterior arch and at the intersection of the vertical line through the center of C 2 inferior articular process and the horizontal line at least 3 mm below the superior rim of the C 1 lamina. The screw of 3.5 mm in diameter was placed in a direction of 10° medial angle and 5° upward angle. After placement of C 1 pedicle screw, the distance from C 1 screw entry point to the medial lateral midpoint of C 1 pedicle, the maximum length of screw trajectory and the actual screw trajectory angles were measured. The direction of screw penetrating through the cortical of C 1 pedicle or lateral mass and the injuries to the vertebral artery and spinal cord were observed.Results Forty pedicle screws were placed on atlas, the mean distance from C 1 screw entry point to the medial lateral midpoint of C 1 pedicle was (2.20±0.42)mm, the maximum length of screw trajectory averaged (30.51±1.59)mm, and the actual screw trajectory angle measured (9.7±0.67)° in a medial direction and (4.6±0 59) ° in a upward direction. Only 1 screw penetrated the upper cortical bone of the atlas pedicle because the upward angle was too large, and 8 screws were inserted so deep that the inferior cortical bone of the C 1 lateral mass was penetrated. But no injuries to the vertebral artery and spinal cord were observed. Conclusion C 1 posterior pedicle screw fixation is quite accessible and safe, but the surgeons should pay attention to the angle and the depth of the screw placement.
出处
《中国修复重建外科杂志》
CAS
CSCD
2004年第5期392-395,共4页
Chinese Journal of Reparative and Reconstructive Surgery
基金
广东省自然科学基金团队资助项目 (2 0 0 2 30 0 1 )~~
