下颈椎椎动脉与横突孔大小及位置关系的影像学研究

Radiolographic study of relationship between vertebral artery and transverse foramen in lower cervical spine

目的:观察下颈椎椎动脉与相应节段横突孔之间的位置关系,探讨行下颈椎椎弓根螺钉固定时椎动脉损伤的风险。方法:筛选50例行CT血管成像(CTA)检查的患者,其中男28例,女22例,要求椎动脉检查正常、颈椎无明显畸形。测量横断位图像中C3～C7左右两侧椎动脉与相应横突孔的有关数据,即横突孔的最大横径(W)、最大矢状径(H),椎动脉直径(AL),椎动脉与横突孔的内(M)、外(L)、前(A)、后(P)边缘的最短距离,椎动脉到椎弓根的最短距离(h),椎动脉面积(AVA),横突孔面积(AF),并计算椎动脉占相应横突孔的面积百分比(AVA/AF)。结果:所有测量指标同一性别同一节段左侧与右侧比较无显著性差异(P>0.05)。除C5的M及C6的L男性大于女性(P<0.05)外,其他各指标同一节段男性与女性比较无显著性差异(P>0.05)。从C3到C6横突孔的W、H和AF均呈逐渐增大趋势,C7横突孔变异较多,H及AF最小。C3～C6的M均小于L(P<0.01),C3、C4及C5平面A小于P(P<0.05),C6平面P小于A(P<0.05)。h在C3最小,为0.5±0.2mm;C7横突孔无椎动脉通过,相应平面上h最长,为7.3±2.7mm。AVA/AF从C3到C6逐渐减小,C3最大为35.7%±15.7%,C6最小为27.4%±12.8%。结论:椎动脉在下颈椎相应横突孔中有相对"宽裕"的空间,椎动脉位于相应横突孔的内侧,C3、C4及C5平面椎动脉偏前,C6平面偏后。在置入下颈椎椎弓根螺钉时,C3椎动脉损伤的风险最大,其次为C6,C7最小。

Objective：To investigate the relationship between vertebral artery and transverse foramens in lower cervical spine and to explore the risk of vertebral artery injury due to pedicle screws implantation. Method：Fifty patients（28 males,22 females）screened by computer tomogram angiography（CTA）were included in our series,patients with cervical spine and vertebral artery abnormality were excluded.Several parameters were measured bilaterally on the cross-sectional image of C3 to C7 including the maximal width（W）and height（H）of transverse foramen,the diameter of vertebral artery（AL）,the shortest distance between vertebral artery and medial（M）,lateral（L）,anterior（A）and posterior（P）border of transverse foramen,the shortest distance between vertebral artery and pedicle（h）,the area of vertebral artery（AVA）and transverse foramen（AF）,and the rate between AVA and AF（AVA/AF）were measured respectively.Result：No difference had been find between right and left side in same segment either in males or in females（P0.05）.No significant difference was noted between males and females except of M in C5 and L in C6（longer in males than in females）.W,H and AF increased from C3 to C6.However,C7 had the lowest H and AF.M was lower than L at C3-C6（P0.01）.A was lower than P at C3,C4 and C5,however a little bit longer than P at C6.h varied from C3 to C7 with the minimun of 0.5±0.2mm at C3 and the maximum of 7.3±2.7mm at C7.AVA/AF decreased from C3 to C6 with the maximum of 35.7%±15.7%at C3 and the minimum of 27.4%±12.8%at C6. Conclusion：Relative＂abundance space＂exists for vertebral artery in transverse foramen.Vertebral arteries lo-cate to the medial part of transverse foramen,and anteriorly in C3,C4 and C5,while posteriorly in C6.The highest risk of vertebral artery injury due to cervical pedicle screw implantation is at C3,secondarily at C6,and the lowest is at C7.