颈椎斜位X线片在颈椎椎弓根钉固定中应用的研究

目的：探讨通过颈椎斜位X线片观察椎弓根的位置和方向，及其在判断椎弓根钉固定中准确，安全地进行钉的作用。方法：人尸体颈椎30例，其中椎动脉造影8例，椎动脉脊髓同时造影6例，根据术前X线斜位片，结合解剖标记定位，选择是钉点及进行钉方向，将直径3．5mm、长度24mm的不锈钢螺钉固定于C2或C3－C6或C7椎弓根中，共160枚，通过术后斜位X线片中判断螺钉在椎弓根的位置，并与CT扫描结果对照，以肯定X线的判断，结果：螺钉位置方向正确者152枚，X线片与CT扫描片的判断完全相符；X线判断螺钉偏向椎弓根外侧边缘5枚，偏向椎弓根内侧的边缘3枚。CT扫描确位于椎弓根外侧边缘3枚，怀疑进入椎动脉孔的2枚；在椎弓根内侧边缘没有进入椎管的3枚。结论：术前通过X线斜位片基本可以解椎弓根方向，上下径；通过术后X线斜位片可较为准确地判断椎弓根钉在椎弓根内的位置及有无进行推动脉孔、椎管的情况，X线与CT的结果差异可能与CT扫描的角度及其伪影有关，该方法简单易行。

Application of cervical oblique films in transpedicular screw fixation

Objectives　To illustrate the functions of oblique films in observing the position of pedicle and fixing the screw through the study of preoperative and postoperative oblique films,and to determine a new,accurate and safe method of fixation.　Methods　In 30 cadavers, 8 had vertebral aortographies and 6 aortographies and myegraphies. According to preoperative films and anatomic marks, transpedicular screws were fixed (diameter 3.5 mm, length 24 mm, 160 stenless steel screws） for (C2)C3-C6(C7). The screw placement position and direction were compared in postoperative onlique film with CT,　and 　thus the result of 　X-ray oblique films was confirmed. Results　152 screws were in right placement and direction, which were confirmed by oblique films and CT. Five screws were estimated by oblique films as deflection outboard of the pedicle (3 by CT), and 3 screws as deflection inboard of the pedicle (2 by CT).　Conclusions　The position and direction of pedicle of the cervical spine cand be detecte by oblique films and may exactly estimate the transpedicular screw placement to see whether it enters the vertebra artery or spinal canal. The difference between oblique films and CT may be related to the scanning angle of CT and pseudomorph in CT.