导航辅助脊柱胸腰段椎弓根钉植入的临床应用

目的探讨临床运用计算机影像导航技术引导脊柱胸腰段椎弓根钉植入的准确性。方法2003年5月-2007年5月，29例患者接受116枚计算机影像导航技术引导脊柱胸腰段椎弓根钉植入手术治疗，T10-T1250枚胸椎弓根钉，L1-L3 66枚腰椎弓根钉。术中记录椎弓根钉植入所需时间及C-臂透视工作次数，椎弓根钉植入完成后，即行C-臂正侧位摄片并与导航路径进行比较测量。术后CT进行椎弓根层面扫描，根据椎弓根钉与椎弓根皮质问关系分为四级：A=在椎弓根内；B=突破皮质，〈2mm；C=突破皮质，2-4mm；C=突破皮质，〉4mm。结果术后CT椎弓根位置扫描显示：A级101枚（87．07％）；B级10枚（8．62％）；C级2枚（1．72％）；D级3枚（2．59％）。1枚椎弓根钉植入平均所需时间：2．73±0．64min（1．15～4．02min）。下胸椎9枚（7．75％）胸椎弓根钉突破皮质，上腰椎6枚（5．17％）腰椎弓根钉突破皮质，且临床观察未发现与椎弓根钉突破皮质相关的神经血管等并发症。植入的椎弓根钉C-臂正侧位摄片与导航路径吻合比较，进钉点均差2．6mm（最大3．1mm），角度均差3．3°（最大5．4°）。结论计算机影像导航辅助脊柱胸腰段椎弓根钉植入，提供二维、多平面实时显示，保证了脊柱胸腰段椎弓根钉植入的准确性及安全性，明显减少放射线的暴露强度。

Clinical accuracy of fluoroscopic computer-assisted thoracolumbar pedicle screw placement

Objective To evaluate the clinical accuracy of computer-assisted fluoroscopy for the placement of thoracolumbar pediele screws. Methods From May 2003 to May 2006,29 cases with 116 thoracolumbar pedicle screw placements guided by computer-assisted fluoroscopy were performed in our department,including 50 in the lower thoracic spine （T10-T12）and 66 in the upper lumbar spine. In operation, time for screw insertion ,and the number of times the C-arm had to be brought into the field. The pedicle screw position and involved vertebrae were routinely assessed with postoperative thin-cut CT by an independent radiologist. The relative position of the screw to the pedicle were graded as follows：A =completely in; B =〈2mm break ; C =2 -4ram break ; D =〉4mm breach. Results Average screw insertion time was 2.73±0.64min（1.15 to 4.02rain）from start of registration to end of insertion for each screw. For 116 screws,101 screws （87.07%）were completely contained within the pedicle. Pedicle break were graded B in 10 screws （8.62%）,C in 2 screws （1.72%）,and D in 3 screws（2.59%）. None of the pedicle break were associated with neurologic or other clinical sequelae. Conclusion Computer-assisted navigation system provides real-time,multiple-plain,two-dimensional visualization of spinal anatomy. The surgeon can perform the thoracolumbar screw insertion procedures confidently with increase of accuracy and safety.