肺门作为躯干重心对强直性脊柱炎胸腰段后凸畸形矫形的意义

目的探索能够代表强直性脊柱炎（ankylosingspondylitis，AS）胸腰段后凸畸形躯干重心的影像学标记，进而设计AS胸腰段后凸畸形的截骨矫形方案。方法不规则物体的重心可通过两个不同方向的悬吊或支撑力线获得，通过手术前后髋轴的支撑力线可寻找 AS 胸腰段后凸畸形患者的躯干重心。38例无脊髓神经症状体征、双髋活动良好的AS胸腰段后凸畸形患者纳入研究。比较AS矫形患者手术前后矢状面平衡距离（ sagittal vertical axis，SVA ）、C7距髋轴中心水平距离（ horizontal distance between hip axis and C7，HDHC ）、T5距髋轴中心水平距离（ horizontal distance between hip axis and T5，HDHT5）、T9距髋轴中水平距离（ horizontal distance between hip axis and T9，HDHT9）、肺门距髋轴中心水平距离（ horizontal distance between hip axis and hilus pulmonis，HDHH ），将矫形前后测量值做统计描述及配对t检验。采用组内相关系数（ ICC ）衡量HDHH的观察者间信度（inter-observerreliability）及观察者内复测信度（intra-observerreliability）。结果矫形前SVA、HDHC、HDHT5、HDHT9、HDHH分别为21.1 cm、12.7 cm、3.5 cm、-3.8 cm、2.7 cm；矫形后分别为9.1 cm、4.2 cm、-2.1 cm、-5.6 cm、0.9 cm。SVA、HDHC、HDHT5、HDHT9矫形前后变化有统计学意义，HDHH 矫形前后变化无统计学意义。HDHH 的观察者间总体信度与观察者内总体复测信度分别为0.958、0.963（ P＜0.001）。结论矫形前后肺门垂线通常总是落在髋轴上，肺门可作为躯干重心的影像学标记应用于AS胸腰段后凸畸形的矫形设计。

Signiifcance of the hilus pulmonis as the center of gravity of the trunk for deformity correction in thoracolumbar kyphosis secondary to ankylosing spondylitis

Objective To investigate a radiological marker for the center of gravity （ CG ） of the trunk in the treatment of thoracolumbar kyphosis （ TLK ） secondary to ankylosing spondylitis （ AS ）, so as to design deformity planning.Methods The CG of an irregular object could be obtained through hanging or supporting it in 2 different directions or points, and the CG of the trunk in the patients with AS TLK would be located by using the preoprative and postoperative hip axis vertical lines. A total of 38 patients with AS TLK were included in this study, who had good hips and no spinal cord injuries. The preoperarive and postoperative radiological parameters were measured, including sagittal vertical axis （ SVA ）, horizontal distance between hip axis and C7 （ HDHC ）, horizontal distance between hip axis and T5 （ HDHT5 ）, horizontal distance between hip axis and T9 （ HDHT9 ） and horizontal distance between hip axis and hilus pulmonis （ HDHH ）. The preoperative and postoperative measurement results were compared by statistical analysis and pairedt-tests. The intraclass correlation coefifcient （ ICC ） was used to determine the intraobserver and interobserver reliabilities of HDHH.Results The preoperative SVA, HDHC, HDHT5, HDHT9 and HDHH values were 21.1 cm, 12.7 cm, 3.5 cm, -3.8 cm and 2.7 cm respectively, and the postoperative values were 9.1 cm, 4.2 cm, -2.1 cm, -5.6 cm and 0.9 cm respectively. The differences between the preoprative and postoperative values of SVA, HDHC, HDHT5 and HDHT9 were statistically significant, and while the differences between the preoprative and postoperative values of HDHH were not. The ICC for overall interobserver reliability was 0.958, and it was 0.963 for overall intraobserver reliability （P〈0.001 ）.Conclusions The hilus pulmonis falls approximately on the hip axis both preoperatively and postoperatively. It is a better radiological marker for the CG of the trunk for deformity planning in AS TLK.