This spine surgery lecture covers complications and revisions in surgery of adolescent idiopathic scoliosis. The lecture begins with an exploration of the reasons why the most feared complication (neurological deficit) occurs and how to detect it before going too far. This is followed by an examination of the difficulties in the reading of the X-rays and proper planning for selection of the levels of fusion. The clinical X-rays are included when the surgery is done at the wrong levels due to incorrect pattern recognition. Finally, the lecture looks at the reasons for inadequate cosmetic results and strategies to overcome this especially rib hump and shoulder imbalance, along with the strategies to treat deep seated and late infections occurring in these constructs.