O-arm导航辅助下胸腰椎椎弓根螺钉置入精确度研究

Study on the accuracy of thoracolumbar pedicle screw installation assisted by O-arm navigation

目的 探讨O-arm导航辅助下胸腰椎椎弓根螺钉置入的准确性和可靠性.方法 回顾性分析2014年3-10月收治的75例实施胸腰椎椎弓根螺钉固定术患者,32例采用O-arm导航辅助置钉（导航组）,43例采用C形臂X线机透视辅助下徒手置钉（透视组）,术后行X线片、CT扫描检查,比较两组螺钉置入的准确性,评价导航组术中导航和术后CT扫描的矢状位和轴位图像中螺钉置入角度的一致性.结果 透视组共置入206枚椎弓根螺钉,一次性置钉成功率为93.2％,置钉准确率为90.8％（一类）,1枚三类螺钉导致L3神经根刺激症状.导航组共置入226枚椎弓根螺钉,一次性置钉成功率为100％,置钉准确率为96.9％（一类）,无三类螺钉,而在术中导航和术后CT扫描的矢状位和轴位图像中,螺钉置入角度差异无统计学意义（P＞0.05）.结论 O-arm导航系统可以提供高清晰度导航图像并实现高精确度导航操作,有效提高胸腰椎椎弓根螺钉置入的准确性,具有良好的可靠性.

Objective To evaluate the accuracy and reliability of O-arm-based thoracolumbar pedicle screw installation.Methods A retrospective review was conducted on 75 patients who had undergone thoracolumbar pedicle screw fixation assisted with O-arm navigation （navigation group,n =32） and C-arm fluoroscopy （fluoroscopy group,n =43） from March to October 2014.All the patients were assessed with X-ray and CT images after operation.Accuracy of screw installation in both groups was compared.In navigation group,screw directions were measured on the sagittal and axial images of intraoperative navigation and post-operative CT scanning to evaluate the concordance.Results In fluoroscopy group,a total of 206 pedicle screws were placed with the one-time success rate of 93.2% and accuracy of 90.8% for screw placement,and one misplaced screw （grade llⅢ） led to L3 nerve root symptom.In navigation group,a total of 226 pedicle screws were placed with the one-time success rate of 100% and accuracy of 96.9% for screw placement,and no screw was grade Ⅲ.Further,there were no significant differences in screw directions on the sagittal and axial images between intraoperative navigation and postoperative CT scanning （P 〉 0.05）.Conclusion O-arm navigation that provides high-resolution images and high precision improves the accuracy of thoracolumbar pedicle screw installation,and possesses good reliability.