胸椎椎弓根形态测量研究

目的:观察不同节段胸椎椎弓根形态特征,探讨其临床意义。方法:测量40具国人胸椎标本的椎弓根横径、矢状径、矢状面夹角、椎弓根间距、椎弓根后缘皮质到椎体前缘皮质距离及椎弓根-椎板夹角,观察椎弓根后缘中点与相应横突根部的关系。结果:（1）除T1外,各节段椎弓根矢状径均明显大于横径（P<0.01）;（2）椎弓根矢状面夹角从T1到T9逐渐减小,T10以下为负角;（3）椎弓根后缘皮质沿其轴线到椎体前缘的长度从T1到T7逐渐增加,T7到T12基本相同;（4）T1与T12椎弓根螺钉拟进钉点位于横突根部中点,T2及T11位于横突根部中上1/3点,其余各节段均位于横突根部上缘。结论:进行胸椎椎弓根螺钉固定时,应根据不同节段椎弓根形态特点,结合X线片或CT片,选择相应的螺钉直径、长度、进钉部位及方向。

A study on the morphology of thoracic pedicles

Objective:To discuss the morphologic features of thoracic pedicles in different segments and its clinical significance. Method: The transverse and sagittal diameter of the thoracical pedicles,sagittal pedicle angle,distance between two pedicles,length of the pedicle from posterior cortex of the pedicles to anterior cortex of the vertebral body, the angle between pedicle and lamina, and the relationship between the middle of posterior cortex of pedicle and the base of transverse process were observed and measured in 40 cadavers. Result:The sagittal diameter was significantly larger than transverse diameter at all segments except T1(P<0.01). (2)The sagittal pedicle angle was decreased gradually from T1 to T9,and negative below the level of T10. (3)The length of the pedicle from posterior cortex to anterior cortex of the vertebra were increased from T1 to 17,and they were the same from T7 to T12. (4)The entry point of T1 and T12 were located at the middle of the base of transverse process at T1 and T12,and located at the upper third at T2 and T11,while at the upper edge of transverse process in other segments. Conclusion: The success of transpedicular fixation needs to have the better understanding of morphologic features in different segmental pedicles and reasonable selection of the diameter, length, the entry point and direction of the pedicle screws based on X-ray and CT films.