Gebhard J S, Schimmer R C, Jeanneret B
Lakewood Orthopaedic Clinic, Colorado, USA.
Spine (Phila Pa 1976). 1998 Oct 15;23(20):2185-9. doi: 10.1097/00007632-199810150-00008.
In this anatomic study, the safety and accuracy of C1-C2 transarticular screw placement was tested in a normal anatomic situation in cadaver specimens using a specially designed aiming device.
To assess the safety and accuracy of transarticular screw placement using the technique described by Magerl and a specially designed aiming device.
Transarticular C1-C2 screw fixation has been shown to be biomechanically superior to posterior C1-C2 wiring techniques. Several clinical series have been reported in the literature. However, no previous study assessing the accuracy or safety of this technique has been published. Structures at risk are the vertebral arteries, spinal canal, and the occiput-C1 joint.
Five frozen human cadaveric specimens were thawed and instrumented with 10 C1-C2 transarticular screws, according to the technique described by Magerl but using a specially designed aiming device described by the senior author (Jeanneret). After screw placement, the accuracy of screw positioning and the distance of the screws from the spinal canal, vertebral arteries, and atlanto-occipital joint were determined by anatomic dissection and radiographic analysis.
The structure at greatest risk was the atlanto-occipital joint, with one screw found to be damaging the joint. Vertebral artery or spinal canal penetration was not observed in any of the specimens. Screw length averaged 45 mm and, with proper length, the screw tip was found to be located approximately 7.5 mm behind the anterior tubercle of C1 on lateral radiographs.
This anatomic study demonstrates that C1-C2 transarticular screw fixation can be performed safely in a normal anatomic situation by surgeons who are familiar with the pertinent anatomy. The aiming device allowed safe instrumentation in all patients. In case of an irregular anatomic situation (e.g., congenital abnormalities or trauma), computed tomographic scan with sagittal reconstruction is recommended-in particular, to obtain information about the course of the vertebral artery.
在这项解剖学研究中，使用一种专门设计的瞄准装置，在尸体标本的正常解剖情况下测试C1-C2经关节螺钉置入的安全性和准确性。
使用Magerl描述的技术和一种专门设计的瞄准装置，评估经关节螺钉置入的安全性和准确性。
C1-C2经关节螺钉固定在生物力学上已被证明优于C1-C2后路钢丝技术。文献中已有多个临床系列报道。然而，此前尚未发表过评估该技术准确性或安全性的研究。有风险的结构包括椎动脉、椎管和枕骨-C1关节。
将5具冷冻的人体尸体标本解冻，按照Magerl描述的技术，但使用资深作者（Jeanneret）描述的专门设计的瞄准装置，置入10枚C1-C2经关节螺钉。螺钉置入后，通过解剖和影像学分析确定螺钉定位的准确性以及螺钉与椎管、椎动脉和寰枕关节的距离。
风险最大的结构是寰枕关节，发现有一枚螺钉损伤了该关节。在任何标本中均未观察到椎动脉或椎管穿透。螺钉平均长度为45mm，长度合适时，在侧位X线片上发现螺钉尖端位于C1前结节后方约7.5mm处。
这项解剖学研究表明，熟悉相关解剖结构的外科医生在正常解剖情况下可以安全地进行C1-C2经关节螺钉固定。该瞄准装置使所有患者都能安全地进行操作。在解剖结构不规则的情况下（如先天性异常或创伤），建议进行矢状面重建的计算机断层扫描，特别是为了获取有关椎动脉走行的信息。
