计算机导航系统和C臂机透视引导颈椎椎弓根螺钉内固定技术的临床对比研究

目的探讨颈椎（C1-C7）椎弓根螺钉内固定的可行性和两种不同置钉方法的精确性。方法通过术后进行X线摄片、CT或术后Iso-C断层扫描等方法,判断C臂机透视引导下置入的145枚和三维导航系统（CT三维导航或Iso—C术中三维导航）辅助下187枚颈椎椎弓根螺钉病例的置钉准确性。结果三维导航系统引导组螺钉置入满意率（97．9％,183／187）明显高于C臂机透视引导组（91．7％,133／145）（χ2=6．705,P=0．010）。且三维导航系统引导组位置不满意的4枚螺钉均发生于早期病例,导航系统使用熟练后未再出现置钉不满意的病例。两组病例均未出现明显的神经血管损伤并发症（C臂机透视引导组2例术后一过性上肢疼痛）。对三维导航系统引导组中25例进行术中导航操作时间和导航精确性的监测。CT三维导航术中工具注册和参考点照合时间平均3．5min（2—8rain）,位置误差率平均0．31mm（0．12—0．56mm,导航仪自动计算）;Iso—C术中三维导航图像采集和传输时间平均6．2min（5—7min）,每颗椎弓根螺钉定位针置入所需时间平均2min（1—3．5min）;术中只需进行2次C臂机透视印证螺钉定位针和螺钉置入的准确性。结论采用三维导航系统辅助,能显著提高椎弓根螺钉置入的精确性,其操作技术有待完善。

Clinical contrast of cervical pedicle screw fixation assisted by C-arm fluoroscopy or 3D navigation system

Objective To evaluate the feasibility and accuracy of cervical(C_2-C_7)pedicle screw fixation assisted by C-arm fluoroscopy or 3D navigation system(CT-based navigation system or Iso-C 3D navigation system).Methods One hundred and forty-five cervical pedicle screws inserted with C-arm fluoroscopy and 187 pedicle screws inserted with 3D navigation system were observed by postoperative CT or Iso-C 3D scan.The process of navigation was investigated.Results In the 145 screws inserted with C-arm fluoroscopy,133 screws are accurate(91.7%),and in the 187 screws inserted by 3D navigation system, 183 screws are accurate(97.9%)(x~2=6.705,P=0.010),and the 4 misplaced screws occurred inthe early stage of navigation system application.The process of navigation was investigated in twenty-five patients.With CT-based navigation,the mean time for registration and surface matching was 3.5 minutes; with Iso-C 3D navigation,the mean time for images collection and transfer was 6.2 minutes.The mean time for screw-marker insertion was 2 minutes.Conclusions 3D navigation system can increase accuracy of cervical pedicle screw fixation obviously.