数字化导向模板技术辅助置钉治疗寰枢椎不稳的临床应用

Clinical application of digital drill template-assisted screw placement for atlantoaxial instability

目的 观察数字化导向模板技术辅助置钉重建寰枢椎不稳的初步临床应用效果.方法 自2010年2月至2013年12月收治28例可复性寰枢椎不稳患者,采用64排螺旋CT层厚1 mm扫描后获得DICOM格式数据.获取数据经Mimics软件三维重建后进行寰枢椎后路螺钉置钉理想钉道的计算机辅助规划,并建立与个体化基板组合形成导向模板.在激光快速成型机上制作导向模板,高温消毒后,应用于临床手术辅助置钉.术后根据颈椎X线片和CT扫描评价螺钉的位置. 结果 应用数字化导向模板为28例患者置入螺钉,其中3例行寰椎椎弓根螺钉＋枢椎椎弓根螺钉联合椎板螺钉固定;25例行寰枢椎后路椎弓根螺钉固定,共置入C1椎弓根螺钉56枚,C2椎弓根螺钉53枚,C2椎板螺钉3枚,术后CT扫描显示所有螺钉均未穿破钉道骨皮质,未出现置钉相关并发症. 结论 数字化导向模板技术能够针对不同螺钉置钉组合方法灵活应用于临床治疗寰枢椎不稳,具有良好的精确性.但数字化导向模板技术在临床上受到人为因素影响的比重增加,有效控制人为因素能够极大地提高置钉精准性并减少神经血管并发症.

Objective To investigate the primary clinical application of digital drill template-assisted screw placement for atlantoaxial instability.Methods CT scan was performed on 28 patients with reducible atlantoaxial instability treated between February 2010 and December 2013 and DICOM format data were obtained to generate a three-dimensional reconstruction model using Mimics software.Optimal trajactory of posterior atlantoaxial screw fixation was designed with a base plate which was an individual complementary template for the posterior atlantoaxial corresponding anatomical surface,and then the drill guide template was materialized in rapid prototyping machine and used intraoperatively to assist screw instrumentation after high temperature sterilization.Position of the screws was determined through cervical radiography and CT scan after operation.Results All patients treated by screw fixation were assisted with drill template.Three patients had atlas pedicle and axial pedicle ＋ lamina screw fixation and the rest underwent posterior atlantoaxial pedicle screw fixation.Fifty-six C1 pedicle screws,53 C2 pedicle screws,and 3 C2 lamina screws were accurately inserted without destruction of the cortical bone and the technique-related complications.Conclusions Digital drill template technique is flexible and accurate enough to assist different combined screw fixation to treat atlantoaxial instability.The accuracy of the screw inserting is increasingly affected by the human factors in clinics,avoiding of which can improve the precision of screw inserting and avoid the neurovascular injury.