下颈椎椎弓根放射影像学观察可描述椎弓根个性化特点及置钉相关性

Individual characteristics of the pedicle and correlation with insertion screws: Radiographic observation of the cervical pedicle

背景:因颈椎椎弓根结构复杂以及形态变异大,术中个性化置钉需要简便、可靠的监测方法。目的:通过放射影像学观察描述下颈椎椎弓根在X射线片上的影像特点,为在下颈椎椎弓根内安全置钉提供帮助,以减少并发症。方法:制备10新鲜颈椎骨标本,以细钢丝缠绑在下颈椎椎弓根狭窄部,摄颈椎正、侧、斜位片,观察下颈椎椎弓根形态在不同投照位置中的变化。结果与结论:X射线片中下颈椎椎弓根的正位片影像是椎体两侧倾斜的管状结构,椎弓根椭圆形截面的长轴向内倾斜。侧位片上椎弓根未被直接显示,仅为重叠在椎体后上壁的高密度影。斜位片清楚的显示了椎弓根狭窄部的4个侧壁及其截面形状。提示颈椎正、斜位片的椎弓根影像可以较好地反映下颈椎椎弓根的形态,对了解椎弓根个性化的特点及置钉有重要意义。

BACKGROUND： On account of the great morphological variation and complex structure of cervical pedicles, so it is essential to get reliable and convenient monitor methods during individual screw insertion. OBJECTIVE： To describe the imaging features of subaxial cervical pedicles on roentgenogram by radiological image observation, which providing the security for cervical pedicles insertion and reducing complications. METHODS： Totally 10 fresh-bone cervical spine specimens were prepared and the isthmus of the pedicle were drawn tightly with radiopaque fine malleable wire. The images of the subaxial cervical pedicles were taken in posteroanterior （PA） and lateral, oblique positions, the morphology of the subaxial cervical pedicles were observed in different projection positions. RESULTS AND CONCLUSION： Radiographs of subaxial cervical pedicles were inclined tubular structure on both sides of the vertebral in PA positions, the long axis of the pedicle elliptical cross section tilte inward. The pedicle image was not shown directly in lateral radiograph, it was only an intensive density area made by the overlapping pedicles on the posterior-superior wall of the vertebrate in lateral radiograph. Four lateral cortex border of the isthmus in the pedicle and the shape of the cervical pedicle were demonstrated clearly in the oblique radiograph. The PA and oblique images of the subaxial cervical pedicles can better reflect subaxial cervical pedicles morphology, it is very useful to grasp the feature of every pedicle and is essential in the individual transpedicular fixation.