腰椎屈伸运动时即时旋转中心和椎弓根螺钉进钉点的位置变化

Distribution of instantaneous rotation centre and the trajectory of the point of pedicle screw insertion in lumbar flexion-extension motion

中文关键词:  腰椎  脊柱非融合  即时旋转中心  椎弓根

英文关键词:Lumbar  Spine non-fusion  Instantaneous centre of rotation  Pedicle

中文摘要:

  【摘要】 目的：观察腰椎屈伸运动时即时旋转中心（instantaneous centre of rotation，ICR）和椎弓根螺钉进钉点（point of pedicle screw insertion，PPSI）的位置变化，为脊柱非融合技术的设计提供参考。方法：61名健康志愿者，男31名，女30名，年龄19~43岁，平均27.8±7.1岁；男性身高174~190cm，平均178.5±4.6cm；女性身高157~168cm，平均164.4±3.3cm。拍摄腰椎屈伸位X线平片，测量各腰椎屈伸时ICR的位置，描绘其分布图；测量矢状位腰椎PPSI屈伸时的位移量、倾斜角度、旋转半径、屈伸活动度，绘制PPSI屈伸运动轨迹。并就男女样本间各测量值进行统计学分析。结果：男性平均身高大于女性（P<0.01），男性L2至S1上终板前后径大于女性（P<0.01），但男性各节段ICR分布位置及PPSI位移值与女性同一节段比较无显著性差异（P>0.05）。各腰椎屈伸运动的ICR前后方向上位于下位椎体上终板的中心附近，L1至L5逐渐向后分布；上下方向上，L1至L4的ICR由腰椎间盘中部移动至下位椎体上终板以下的位置，L5则回归至椎间盘中部。各腰椎屈伸运动时PPSI矢状位上呈由后下至前上的弧线轨迹，L1~L4其位移量和倾斜角度逐渐增大，L5两值同时减小；其旋转半径与腰椎序列无明确关系。L1/2至L5/S1屈伸活动度逐渐增加。结论：各腰椎屈伸运动具有特殊性和规律性，提示不同节段的非融合手术需要有与该节段特有活动参数相匹配的器械，以更好地重建脊柱生理活动。

英文摘要:

  【Abstract】 Objective：To investigate the instantaneous centre of rotation（ICR） and the point of pedicle screw insertion（PPSI） trajectory during lumbar flexion-extension motion and to provide the data for design of spine non-fusion technique.Method：61 healthy volunteers（31 males and 30 females） with the average age of 27.8±7.1 years（range，19-43 years） were included in this series.The average height for male and female was 178.5±4.6cm（range，174-190cm） and 164.4±3.3cm（range，157-168cm） respectively.Based on lumbar flexion-extension X-ray，the ICR position and distribution was first demonstrated，then the PPSI sagittal displacement， angular variation，rotation radius and flexion-extension ROM during flexion-extension movement were measured.The data between male and female were analyzed statistically.Result：Although greater height and greater L2-S1 upper-endplate posterior-anterior width for males than females（P<0.01），the ICR distribution and PSAP displacement at each segment did not show sex-related difference（P>0.05）.In posterior-anterior direction from L1 to L5，ICRs during lumbar flexion-extension motion lied approximately in the middle of the upper-endplate of lower vertebra with a backward tendency.In cranial-caudal direction from L1 to L4，ICRs moved from the middle of the disc to the upper-endplate of lower vertebral，but ICR of L5 returned to the middle of the disc.In sagittal plane，the PPSI of each level moved from inferoposterior to superoanterior with an arc trajectory.The PPSI displacements and angular variation increased from L1 to L4，however，these two decreased in L5 simultaneously.The rotation radius had no relationship with lumbar segment.Flexion-extension ROM from L1/2 to L5/S1 increased gradually.Conclusion：Lumbar flexion-extension motion is characteristics and regular which indicate that non-fusion surgery at different lumbar level should be associated with relative device get better reconstruction of the spine physioactivity.