Medi Help Line Co., Ltd.

Background Spinal balance analysis is critical to the diagnosis and treatment of adult spine deformity (ASD), and radiography is the current gold standard. This study aims to develop a new spinal balance analysis system based on the 3D full body scanner and compare it to X-ray parameters. Methods Ninety-seven participants underwent 3D full body scanning, whole spine X-rays, clinical questionnaires and body composition analyses. After 3D full body scanning, 5 inflection points (ear, shoulder, hip, knee, ankle) were automatically labeled in the sagittal plane. Three concepts are created including angle between two inflection points with respect to the plumb line, horizontal distances between two points in the sagittal plane and the angle between three points. For the coronal plane, shoulder gradient was analyzed automatically. Multiple x-ray parameters about cervical, thoracolumbar and whole spine sagittal balance and coronal balances were analyzed and compared using correlation analyses. Partial correlation analyses and multiple regression analyses were done combining body composition scores and clinical questionnaire scores. Results The correlation coefficient (C.C.) of dAB_hor (horizontal distance between ear and shoulder in the sagittal plane) and C2-C7 SVA was 0.478 (p-value < 0.001). The C.C. of aAC_sag (sagittal angle of ear-hip from the plumb line) and ODHA was 0.336 (p < 0.001). About coronal balance, the C.C. of shoulder gradient from 3D scanner and clavicle angle from x-ray was 0.373 (p < 0.001). The C.C.s were merely affected by body composition data. But in multiple regression analysis, BMI affected 3D scanner data. Clinical symptoms showed a correlation with both aBCD(shoulder-hip-knee angle) and aCDE(hip-knee-ankle angle), which may reflect a compensatory knee flexion for positive sagittal imbalance. Conclusions A new analysis system of spine balance based on a 3D full-body scanner has a statistical correlation with X-ray and shows clinical correlation by representing the compensatory mechanism of ASD.