青少年特发性胸椎侧凸顶椎区椎弓根及椎管的形态学特征

The morphological abnormalities of pedicles and spinal canal in the apical region of adolescent idiopathic thoracic scoliosis

目的：探讨青少年特发性脊柱侧凸（adolescent idiopathic scoliosis，AIS）患者主胸弯顶椎区椎r）根与椎管的形态特点及其对椎弓根螺钉置钉安全性的影响。方法：收集2008年6月～2010年9月收治的28例右胸弯且以T8为顶椎的AIS患者及13例年龄匹配胸椎正常青少年（对照组）的站立位全脊柱正佗X线片及胸椎CT资料。在站立位全脊柱止位x线片上测量AIS患者主胸弯Cobb角及椎体偏移距离（the vertebral translation．VT）：在CT片上测量AIS患者顶椎区各椎体（T7～T9）及对照组相应柞体的椎管轴切面面积（the axial section area of spinal-canal，ASA）、椎管矢状面直径（the sagittal diameter of the spinal-canal，SDS）与冠状面卣径（the coronal diameter of the spinal-canal，CDS）、椎弓根直径（the transverse pedicle diameter，TPD）、双侧椎弓根夹角（the angle between bilateral pedicles，ABP）及椎体旋转度（the vertebral rotation，VR）；利用独立样本t检验与多元线性回归分析比较两组人群间各形态参数数据是否存在显著性差异及AIS患者各形态参数间的相关性。结果：AIS患者主胸弯顶椎区ASA、CDS及ABP均显著大于对照组（P〈0．05）；AIS患者主胸弯顶椎区凹侧TPD显著小于对照组同侧同节段TPD（P〈0．05），凸侧TPD与对照组同侧同节段比较无统计学差异（P〉0．05）。两组间SDS无统计学差异（P〉0．05）。多元线性回归分析显示AIS患者主胸弯顶椎区CDS与VT相关（T7：Beta=0．094，P=0，022；T8：Beta=0．630，P=0．005；T9：Beta=0．119，P=0．014），主胸弯顶椎区ABP和凹侧TPD与患者性别、年龄、Cobb角、vR及VT均尢显著相关性。结论：AIS患者主胸弯顶椎区ASA、CDS、ABP显著大于胸椎正常青少年同节段相应参数，凹侧TPD显著小于胸椎正常青少年同节段相应参数，这些可能是影响AIS矫形于术中主胸弯顶椎区置钉安全性的重要危险因素。

Objectives： To investigate the morphological characteristic of thoracic pedicles and spinal canal in the apical region of idiopathic thoracic scoliosis and its influence on the accuracy of pedicle screw place- ment. Methods： 28 adolescent idiopathic scoliosis（AIS） patients with the apical vertebra at T8 and 13 age- matched controls were included in this study from June 2008 to September 2010. Standard up-standing pos- teroanterior whole spine radiography was performed to investigate the Cobb angle of main thoracic curve and the vertebral translation（VT） of each vertebra in the apical region（T7-T9）. Furthermore, CT scanning was also performed to investigate the morphological parameters of pedicles and spinal canal of each vertebra, which in- cluded the axial section area of spinal-canal（ASA）, the sagittal diameter of the spinal-canal（SDS）, the coronal diameter of the spinal-canal（CDS）, the transverse pedicle diameter（TPD） and the angle between bilateral pedi- cles（ABP）. Independent samples t-test analysis and multiple linear regression analysis were performed to deter- mine the differences of the above morphological parameters between the two groups, and the correlations be- tween the investigated morphological parameters in AIS group were investigated. Results： The ASA, CDS and ABP were significantly larger in AIS patients than those in controls （P〈0.05）; while TPD of AIS patients inconcave side was significantly thinner than that in controls（P〈0.05）. No significant difference was found in the comparison of the SDS and the TPD in convex side between the two groups. In addition, the results showed that the CDS was correlated with the VT（T7： Beta=0.094, P=0.022; TS： Beta=0.630, P=0.005; T9： Beta=0.119, P=0.014）; while no significant correlations were found between the ABP or the TPD in concave side and the gender, age, VR and VT of AIS patients. Conclusions： The ASA, CDS and ABP are significantly larger in AIS patients than those in controls, while the TPD of AIS patients in concave side is significantly thinner than that in controls, which may be a potential risk factor for pedicle screw resplacement.