术中CT引导下寰枢椎复位、固定

目的：探讨术中CT引导下寰枢椎复位、固定手术的临床疗效。方法： 选择2015年1月至8月北京大学第三医院骨科行术中CT引导下寰枢椎复位、固定术的16例患者进行回顾性分析，其中男7例，女9例,年龄26~68岁，平均49.9岁。16例中12例为陈旧性寰枢关节不稳定或脱位，4例为C2齿突新鲜骨折、脱位。16例中14例进行了寰枢椎植骨融合术，2例仅寰枢椎固定、未进行植骨。术中CT使用时机：(1)在术中置钉前CT扫描评估寰枢椎复位情况；(2)术中寰枢椎椎弓根穿刺过程中，CT扫描引导穿刺方向（其中2例患者联合使用3D打印个体化导板和术中CT引导寰枢椎置钉）；(3)置钉完成后应用多平面CT重建图像评估螺钉位置及寰枢关节复位情况。计算术中CT扫描的次数，将同期实施徒手寰枢椎内固定的19例作为对照组，比较两种术式的置钉准确性。结果： 本组11例术中CT扫描1次、4例2次、1例3次，平均1.4次。16例中CT扫描发现2例寰椎螺钉位置不佳，在术中进行了修正，未出现神经、血管损伤及伤口感染病例。所有病例获得随访，随访时间3~10个月，平均6.7个月。16例术后寰枢关节均获得解剖复位。术后3个月复查CT见寰枢融合良好（14例），齿突骨折骨性愈合（2例）。11例术前合并脊髓病患者脊髓功能改善，平均JOA评分由12.1分提高至14.4分。至最后一次随访均未发现断钉、断棒、内固定松动等并发症发生。置钉准确性比较，发现16例CT组所有寰枢椎螺钉位置均满意，而徒手置钉组19例中有2例4枚的螺钉位置不佳（10.5%）。结论： 应用术中CT引导下寰枢椎复位、固定术提高了寰枢椎置钉的准确性，判断寰枢关节复位程度更加精确，术中即刻了解螺钉位置，一定程度上避免返修，显示该术式临床效果良好。

Atlantoaxial reduction and fixation guided by the intraoperative CT

Objective: To evaluate the clinical result of atlantoaxial reduction and fixation guided by the intraoperative CT.Methods: Sixteen cases were retrospectively studied, including seven males and nine females, with the mean age of 49.9 years.Twelve cases were diagnosed as chronic atlantoaxial instability or dislocation, while four cases as acute odontoid fracture and dislocation.Among the sixteen cases, fourteen underwent atlantoaxial fusion, while two underwent temporary atlantoaxial fixation without fusion.The intraoperative CT was used in the setting of: 1.Evaluating the atlantoaxial reduction before the screw insertion;2.Guiding the C1 and C2 pedicle drilling (two cases using additional three-dimensional printing drilling template);3.Evaluating the position of the screws and reduction after the atlantoaxial fixation.In addition, three-dimensional drilling template combined with intraoperative CT was used in two cases.CT scanning frequency was calculated.To evaluate the accuracy rate of screw fixation under the intraoperative CT, 19 cases without the intraoperative CT were studied as the control group.Results: Averaged CT scanning frequency was 1.4 times (Once in eleven cases, twice in four and three times in one).Among the sixteen cases, mal-positioned C1 screws were found and revised in two cases.No spinal cord injury or vertebral artery injury occurred.The follow-up ranged from three to ten months, with the mean of 6.7 months.Fourteen cases achieved solid osseous fusion, and two with temporary fixation had odontoid fracture union.Anatomic reduction was achieved in all the cases.Eleven cases with preoperative myelopathy had postoperative improvement and their mean JOA scores improved from 12.1 to 14.4.To the last follow-up, no hardware complications were found including screw broken, rod broken or fixation loosening.All the screws of intraoperative CT group had good positions.For 19 cases of the control group, there were two cases of mal-positioned screws (10.5%).Conclusion: Advantages of atlantoaxial reduction and fixation guided by the intraoperative CT included: improving the accuracy of the atlantoaxial screws, exactly evaluating the reduction of the atlantoaxial joint, immediately discovering the mal-positioned screws and avoiding the revision surgery.A good clinical result was found in the preliminary study.