胸腰段爆裂骨折后凸畸形不同测量方法比较

Comparison of various measurements for thoracolumbar kyphosis after burst fracture

目的：比较常用胸腰段骨折侧位x线片不同测量方法测量后凸角度的可信度及可重复性。方法：40例胸腰段爆裂骨折患者的侧位X线片，让3位脊柱外科医师应用6种测量方法测量后凸角度，（1）伤椎头侧邻近椎体上终板和尾侧邻近椎体下终板平行线的垂线夹角；（2）伤椎下终板和头侧邻近椎体上终板平行线的垂线夹角；（3）伤椎头侧和尾侧邻近椎体后壁平行线的垂线夹角；（4）伤椎头侧邻近椎体下终板和尾侧邻近椎体上终板平行线的垂线夹角；（5）伤椎上终板和下终板平行线的垂线夹角；（6）后凸比率，即伤椎头侧邻近椎体前下缘至尾侧邻近椎体前上缘距离（a）／伤椎头侧邻近椎体后下缘至尾侧邻近椎体后上缘距离（b）。以3周为间隔分别独自测量两次后凸角度，对测量结果进行统计学分析。结果：方法1组内相关系数高度一致（r=0.84-0.95）.其次是方法4（r=0.75-0.90）。各种测量方法三位测量医师所得结果组内一致性（重复测量5°以内变化）为76％-98.5％，方法1显示较好的一致性（92.4％-98.5％）。配对检验显示，不同观察者之间，组间可信度相关系数为0.53-0.90，方法1显示最高组间可信度相关系数（0.85，范围0.75-0.92），其次是方法4（0.81.范围0.71-0.89）。结论：测量伤椎头侧椎体上终板和尾侧椎体下终板平行线的垂线夹角作为骨折椎体后凸角具有最佳组内和组间可信度。

Objective：To compare the various measurements of lateral view X-rays for thoracolumbar burst fracture and determine their realiability and repetitiveness of measuring the kyphosis.Method：To determine the angle of kyphosis,forty lateral radiographs of thoracic and lumbar burst fractures from the department of spinal surgery in Tianjin hospital were measured by three spine surgeons,using 6 different measurement methods.（1）measuring the included angle formed by two vertical lines perpendicular to the lines parallel to the superior endplate of the vertebral body,one above the injured vertebra and to the inferior endplate of the vertebral body,one below the injured vertebra; （2）measuring the included angle formed by two vertical lines perpendicular to the lines parallel to the superior endplate of the above vertebral body and to the inferior endplate of the fractured vertebral body; （3）measuring the included angle by the two vertical lines perpendicular to the lines parallel to the posterior wall of the vertebral body above and below the injured vertebra; （4） measuring the included angle by two vertical lines perpendicular to the lines parallel to the inferior endplate of the above vertebra and the superior endplate of the below vertebra; （5）measuring the included angle by two vertical lines perpendicular to the lines parallel to the superior endplate and the inferior endplate of the injured vertebra; （6）kyphosis ratio,distance from the anterior margin of inferior endplate of the vertebrae above the injured vertebra to the anterior margin of superior endplate of the vertebra below the injured vertebra （a）/distance from the posterior margin of inferior endplate of the vertebra above the injured vertebra to the posterior margin of superior endplate of the vertebra below the injured vertebra （b）.All radiographs were measured for kyphosis angle two times at an interval of 3 weeks.The results were studied statistically.Result： Method 1 had a higher consistency of correlation coefficient within the group（r=0.84-0.95）,and method 4 was the next （r=0.75-0.90）.The measurement agreement（the changes within 5° by repeated measuring） by three observers ranged from 76.0% to 98.5% for all methods,but method 1 showed the best agreement （92.4%- 98.5%）.Paired comparison indicated the reliability correlation varied considerably from 0.53 to 0.90 among the observers.Method 1 showed the highest reliability coefficient 0.85（range,0.75-0.92） in the groups,followed by method 4,reliability coefficient was 0.81 （range, 0.71-0.89）.Conclusion ： Method 1 showed the best reliability of the measurement performed by one or different observers.