Anterior vertebral body tethering (AVBT) is a novel, minimally invasive, growth modulation technique that was recently approved by the FDA under a Humanitarian Device Exemption (HDE). The goal of AVBT is to control curve progression by applying compression on the convex side of the spine deformity. While there has been great initial enthusiasm about the technique as an alternate treatment option to spinal fusion for skeletally immature children with scoliosis, there is a need to better understand the long-term outcomes. The purpose of this study is to report the long-term clinical outcomes of skeletally immature patients treated with AVBT, specifically: 1. The effect on three-dimensional spine growth as compared to normal controls 2. Maintenance of major Cobb angle less than or equal to 50 degrees at skeletal maturity 3. Complications associated with both the procedure and the device