应用交互式医学影像控制系统仿真设计椎弓根螺钉最佳进钉通道

A mimics study on pedicle measurement and simulation of pedicle screw trajectory

目的:探讨第三腰椎(L3)椎弓根螺钉最佳钉道位置。方法:选取50例(男30例,女20例)正常成人的腰椎CT扫描数据,通过交互式医学影像控制系统(MIMICS)建立仿真椎体模型,获取L3椎弓根轴线及最小截面的中心点M。通过"人字嵴"确定进钉点N1并与中心点M点连线模拟钉道T1,"交点法"确定进钉点N2并与中心点M连线模拟螺钉钉道T2,分析模型中钉道位置及角度。8例腰椎骨折患者术前参考仿真钉道设计手术方案,并行螺钉置入,术后观察螺钉位置情况。结果:MIMICS上测量L3椎弓根横径(9.57±0.98)mm,矢径(14.89±0.78)mm。T1钉道与椎体水平面夹角1.5°±1.0°,矢状位夹角12.0°±1.5°;T2钉道与椎体水平面夹角3.0°±1.0°,矢状位夹角10°±1.5°。8例患者应用MIMICS设计钉道方案行腰椎后路固定术,术后影像学显示螺钉位置良好。结论:MIMICS能够精确测量椎弓根各项参数,根据其测量数据设计钉道方案在临床上具有一定参考意义。

Objective：To investigate the best pedicle screw trajectory of the 3rd lumbar vertebra（L3） by mimics method.Method：CT data of 50 lumbar from normal adults（including 30 males and 20 females） were enrolled,and simulating vertebral models were established using materialise′s interactive medical image control system（MIMICS）.Point M was defined as the center of the smallest cross-section of L3 pedicle.Simulating the screw trajectory（T1 and T2） connecting entrance point M and point N1 and N2 respectively.The screw channel and orientation were analyzed which were used in preoperative surgical plan 8 cases who sustained lumbar spine fracture.Result：The L3 pedicle cross-sectional diameter was（9.57±0.98）mm,and the sagittal diameter was（14.89±0.78）mm.The horizontal and sagittal angle of T1 channel was 1.5°±1.0° and 12.0°±1.5° respectively,while those for T2 channel was 3.0°±1.0° and 10°±1.5° respectively.8 patients had screws placed under the guide of MIMICS,and good screw position was noted radiographically.Conclusion：The MIMICS can simulate pedicle profile accurately,which can be used in clinical practice.