三维导航在下腰椎术中即时应用的观察

Necessity of intraoperative three-dimensional navigation for low lumbar spine： a randomized controlled study

目的 观察导航及传统手术方式在下腰椎术中不同节段螺钉置入精确性的差异及相关影响因素.方法 本研究为前瞻性的随机对照研究,包括2011年3月至2012年5月间北京积水潭医院脊柱外科所有接受开放性腰椎手术共188例,并在L4、L5节段均置入椎弓根螺钉的病例.按照1∶3的比例随机分为导航组及对照组.采用术后CT三维重建图像判断L4及L5螺钉的位置,根据螺钉穿出椎弓根是否超过2 mm将螺钉位置分为侵害椎弓根和未侵害椎弓根两组.结果 共有188例患者纳入研究,其中导航组47例,对照组141例.两组患者的出血量,住院时间及改善情况,差异均无统计学意义（均P＞0.05）.导航组患者手术时间更长,差异有统计学意义（P＜0.05）.在L4椎弓根,导航组94枚螺钉中93枚（98.9％）未侵害椎弓根,对照组282枚螺钉中273枚（96.8％）未侵害椎弓根,两者差异无统计学意义（P＞0.05）.在L5椎弓根,导航组94枚螺钉中93枚（98.9％）未侵害椎弓根,对照组282枚螺钉中260枚（92.2％）未侵害椎弓根,在L5椎弓根导航组的置钉准确性更高（P＜0.05）.结论 在L5椎弓根,尤其是术前CT显示腰椎滑脱或小关节增生造成解剖标志缺失、或髂骨内聚、或低年资操作者的情况下建议应用术中即时三维导航辅助置入椎弓根螺钉以增加手术的准确性及安全性.

Objective To compare the accuracy of lower lumbar pedicle screw placement at different levels with or without navigation system.Methods A prospective randomized controlled trial was conducted for patients undergoing open lumbar surgery with pedicle screws at both L4 and L5 levels from March 2011 to May 2012.The accuracy of pedicle screws at L4 and L5 level were evaluated by three-dimensional postoperative computed tomography （CT）.There was no apparent violation of pedicle or 〈 2 mm perforation of pedicle in non-violation group while ≥2 mm perforation of pedicle in violation group.Results A total of 188 patients were recruited and assigned randomly into navigation （n =47） and control （n =141） groups.Two groups did not differ in estimated blood loss volume,length of hospital stay,Japanese Orthopedics Association （JOA） score or JOA recovery rate （P 〉 0.05）.Navigation group had a longer operative duration （P 〈 0.05）.At L4 level,93/94 screws （98.9%） in navigation group and 273/282 screws （96.8%） in control group did not violate pedicle （P 〉0.05）.At L5 level,93/94 screws （98.9%） in navigation group and 260/282 screws （92.2%） in control group did not violate pedicle.Thus navigation could achieve a higher accuracy at L5 level （P 〈 0.05）.Conclusion The profile of L5 pedicle at coronal plane is tilting oval.Screw may easily violate medioinferior part of pedicle and cause injures of nerve root.For improving the accuracy and safety of pedicle screw at L5 level,we recommend using intraoperative three-dimensional navigation for spondylolisthesis or facet hypertrophy,iliac cohesion or junior operator.