Reliability of radiographic assessment of growth modulation from anterior vertebral body tethering surgery in pediatric scoliosis

Purpose To assess the reliability of vertebral height and angular measurements for anterior vertebral body tethering (AVBT). Methods Eight observers measured PA radiographs of 15 idiopathic scoliosis patients treated with AVBT, pre-operative and 4-year follow-up. Vertebral wedging, disc wedging, convex vertebral body heights, and concave vertebral body heights of the 3 apical vertebrae were measured. For each observer, there were a total of 90 measurements for vertebral body height and 75 measurements for all wedging types At least 14 days elapsed between first and second round measurements. Results From the pre-operative to the 4-year follow-up time-point, the total wedging angle over the 3 peri-apical levels fell from 30 ± 7° to 16 ± 6° ( p