This study checks if a treatment called The Tether, used for scoliosis, is safe and helpful over a long time. **Scoliosis** is a condition where the spine curves sideways. The Tether is a type of surgery called Anterior Vertebral Body Tethering (AVBT). In AVBT, screws and a strong cord are used to help straighten the spine as you grow. **Idiopathic scoliosis** means the curve in the spine has no known cause. This study is important because while spinal fusion is common, AVBT might be better for some children as it can keep the spine flexible. Only certain hospitals and doctors, who are part of a special group and are trained to use The Tether, can join this study. They will be watching patients who have had this surgery to see how well they do over time.

• Study involves long-term follow-up with patients who have had AVBT.
• Participants must have a specific type of scoliosis and be growing (skeletally immature).
• Participants must be willing to follow study visits and instructions.