Construction And Study Of The Full-length X-ray Posture Scale

Objective:On the premise of meeting the requirements of precision surgery in modern orthopaedics,within the framework of the existing biomechanical parameter collection system,a clinically practical lower extremity full-length X-ray posture scale was constructed and tested for reliability and validity.The scale is used to quantitative grading evaluation of full-length X-ray posture and to assist orthopaedic surgeons in judging whether the full-length X-ray of patients’ lower extremities are standard or not.Methods:To screen and determined the items of the scale,We reviewed of the lower extremity biomechanical parameter collection system which based on the radiology,and consult the literature review,knowledge map technology analysis and experts advice,and 3 bony landmarks that could determine the posture of the lower extremity were determined;30 young healthy volunteers were included,to collected full-length CT data of both lower extremities and used to 3D modeling.The 3D models of both lower extremities were rotated inside/outside-30 to 30 degrees.One lower extremity model was obtained for every 1 degree of rotation,and 122 double lower limbs multi-pose model sample were obtained for each case.Through the maximum density projection technology,the lower limb posture is rotated in the three-dimensional space within the research range,and the two-dimensional plane is proportionally affine to construct a 2D simulation data set;the lower limb posture is quantitatively divided into standard,light,medium,severe internal or external rotation 7 orders of magnitude posture.According to the different weights of the three bony landmarks,we respectively assigned them the scores of-1～-4/1～4,On this basis,the full-length X-ray posture scale which including diagrams,numerical values,and language descriptions was formed;and the reliability and validity analysis were determined.Results:The full-length X-ray posture scale constructed in this study can qualitatively and quantitatively classify the posture of lower limbs into standard posture,light,medium and severe internal or external rotation posture.The content validity index(CVI)of each item of the scale was 0.89 ～ 1.00,and the total CVI was 0.955.The results of test-retest reliability evaluation showed that the intraclass correlation coefficient(ICC)was 0.993(95% confidence interval 0.874-0.890);Cronbach’s ɑis 0.882,The ICC of the tester at different times were 0.954,0.960 and 0.989.The results of reliability evaluation among testers showed that the ICC of the first,second and third tests of senior professional doctors group were 0.926,0.940 and 0.978;The comprehensive ICC is 0.989;The intermediate professional titles group ICC of the first,second and third tests were 0.936,0.948 and 0.989 and comprehensive ICC is0.990.It can be seen that the full-length X-ray posture scale constructed in this study has high reliability in two groups,and has high consistency between two groups also,the scale has strong stability and reliability.Conclusions:The full-length X-ray posture scale constructed in this study has good content validity,test-retest reliability and tester reliability,and can evaluate the posture of the full-length X-ray that obtained in clinical qualitatively and quantitatively.