Signiifcance of the hilus pulmonis as the center of gravity of the trunk for deformity correction in thoracolumbar kyphosis secondary to ankylosing spondylitis
SONG Kai
ZHANG Yong-gang
LI Jie-jing
YU Wen
TANG Xiang-yu
ZHANG Guo-ying
ZHENG Guo-quan
CUI Geng
ZHANG Xue-song
MAO Ke-ya
WANG Zheng
WANG Yan
Abstract：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.
Keywords：SpondylitisankylosingKyphoplastyHilus pulmonisOrthopedic proceduresThoracic vertebraeLumbar vertebrae
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 756-762 )