The “stable-to-be vertebra” (StbV) is vertebra most closely bisected by central sacral vertical (SV) line. A, In this patient, stable-to-be vertebra is at L5. B, On traction radiograph, it is at L3. C, The patient was treated with growing rod instrumentation extending to L3. D, At 6-year follow-up, correction is well maintained with no evidence of distal adding on.