电磁导航系统结合Stagnara投照法在特发性脊柱侧凸手术中的应用

Use of electromagnetic navigation system combined with Stagnara fluoroscopy in idiopathic scoliosis surgery

目的：探讨在特发性脊柱侧凸三维矫形术中应用电磁导航系统结合Stagnara投照法采集C型臂X线透视图像对椎弓根螺钉置入准确性与安全性的影响。方法：2006年4月～2008年12月在电磁导航辅助下行特发性脊柱侧凸二三维矫形术47例（导航组），共置入椎弓根螺钉492枚；2004年6月-2006年4月在C型臂X线机透视下行特发性脊柱侧凸三维矫形术39例（透视组），共置入椎弓根螺钉454枚，两组均采用Stagnara投照法采集C型臂X线透视图像。术后行CT薄层平扫加椎弓根矢状面二维重建，通过测量椎弓根皮质外缘与穿出的螺钉边缘的垂直距离对椎弓根螺钉位置进行评价，并分为A、B、C、D级，以A级和B级合并计算优良率。结果：导航组的手术时间为165～420min，平均233．7min，透视组为175～365min，平均236．1min，两组比较无显著性差异（P〉0．05）；导航组术中出血量为450～1650ml，平均712．2ml，透视组为550～1900ml，平均794．9ml，两组比较有显著性差异（P〈0．05）。导航组术后椎弓根螺钉位置A级476枚，B级9枚，C级5枚，D级2枚，优良率为98．5％：透视组A级411枚，B级14枚，C级17枚，D级12枚，优良率为93．6％，两组置钉优良率比较有显著性差异（P〈0．05）。导航组无神经、血管并发症发生，透视组2例在术中发生螺钉损伤硬膜囊，1例术后发现螺钉刺激神经根。结论：在特发性脊柱侧凸三维矫形术中应用电磁导航系统结合Stagnara投照法采集C型臂X线透视图像可降低椎弓根螺钉的误置率，减少术中出血量，提高手术安全性。

Objective：To explore the accuracy and safety of pedicle screw placement under electromagnetic navigation system combined with Stagnara fluoroscopy in idiopathic seoliosis surgery.Method：From April 2006 to December 2008,47 patients with idiopathic scoliosis had a total of 492 pedicle screws placement by the aid of electromagnetic navigation （navigation group）;and from June 2004 to April 2006,39 cases of idiopathic scoliosis had a total of 454 pedicle screws placement under fluoroscopic as control（fluoroscopy group）.Tbe C- arm fluoroscopic images of two groups were both obtained by Stagnara view.The pedicles of all patients were subjected to postoperative CT scan and two-dimensional reconstruction to assess the screw orietation by measuring the perpendicular distance between the pedicle cortical wall and the screw surface.All the pedicle screws＇ placement were classified as grade A,B,C and D according to the positions of pedicle screws and grade A and B were added to get the excellent and good rate.Result：In navigation group,the average surgical time was 233.7min（range,165-420min）,while 236.1min（range,175-365min） in fluoroscopy group,there was no signifcant difference between two groups （P〉0.05）.The mean blood loss volume was 712.2ml （range,450- 1650ml） in navigation group,while 794.9ml （range,550-1900ml） in fluoroscopy group,which had statistical signifeances between two groups （P〈0.05）.According the classification of pedicle screw placement,in navigaton group,476 screws were graded as A,9 as B,5 as C and 2 as D,with the excellent and good rate of 98.5%; while in fluoroscopy group,411 screws were graded as A,14 as B,17 as C 17 and 12 as grade D,with the excellent and good rate of 93.6%,which had signifcant difference between two groups（P〈O.05）.No neurovascular complications occurred in navigation group.However,in fluoroscopy group,2 eases had dural sac perforation and 1 patient had neurological deficit due to misplaced screws.Conclusion：In idiopathic seoliosis surgery, electromagnetic navigation system combined with Stagnara fluoroscopy can decrease the screw misplacement rate and the blood loss volume as well as ensuring safety of the surgery.