Saving Fusion Levels in Lenke 1/2 AR Curves

You’re staring at the distal lumbar spine, cursor hovering between vertebrae, asking the AIS (adolescent idiopathic scoliosis) question: “Do I really need to go that low?”

For Lenke 1 and 2 curves with an AR modifier, that question usually comes with a warning label: risk of adding-on.