中下胸椎肋凹位置的研究及侧前方置钉数字化模拟

目的 为临床提供中下胸椎侧前方固定以肋凹为参照物的解剖学数据。 方法　在25～60岁（平均43岁）40例完整的中下胸椎(T4～12)标本中测量肋凹前缘与椎孔前缘间距离(DCFC),椎孔前缘与椎间孔前缘间距离(DCF),肋凹下缘与上终板上缘的距离(DIFSP);对6例T4～12非脊柱疾患CT资料三维重建，模拟置钉并测量其钉道长。 结果　肋凹前缘与椎孔前缘间距离,在胸椎中下段由正变负；椎孔前缘与椎间孔前缘间距离，在胸椎中下段变化不大，最小值出现在T6，最大值出现在T4。肋凹下缘与上终板上缘的距离由T4到T12逐渐增大，呈直线上升的趋势。随着椎序的增加，置钉点坐标逐渐移向椎体前上方，钉道也逐渐增长。 结论　随着椎序的增加，肋凹逐渐向后下方移动，其位置有规律可循，可以作为胸椎中下段侧前方置钉的参照点，其钉道长随椎序逐渐增大，可参考本文数据进行置钉点和螺钉长度的选择。

Anatomic allocation and digital simulation of the costal facet of the middle and lower thoracic vertebra

Objective　To provide anatomic data for lateral and anterior fixation of the middle and lower thoracic vertebra according to the location of costal facet.   Methods　On 40 intact specimens of the middle and lower thoracic vertebra((T4～T12), with the age from 25 to 60, the distances from anterior border of costal facet to anterior border of vertebral foramen (DCFC), from anterior border of vertebral foramen to anterior border of intervertebral foramina(DCF), from inferior border of costal facet to superior border of superior terminal plate(DIFSP) were measured respectively. CT data of 6 healthy adults were used to reconstruct and simulate screw canal fixation.  Results    The DCFC decreased gradually from the middle to lower thoracic vertebra, however, there were no obvious difference for DCF, despite of minimum value of T6, and maximum value of T4.  DIFSP gradually increased from T4 to T12.  The coordinate of the screw gradually removed to the superior of the lower thoracic vertebra, with the increased length of screw canal.   Conclusions    The location of costal facet gradually reaches the posterolateral of vertebra from middle to lower thoracic vertebra, which is a valuable reference for determining the site of screw fixation and the length of screw canal.