Preoperative planning involves the standard evaluation of history, physical examination, and radiographic data. In this particular patient population, there are four specific issues to consider. First, it is important to understand the degree of transverse plane asymmetry present within the pelvis as this may alter the previously planned trajectory for SAI screw insertion (6). An iliac wing that appears narrower on the radiograph will pose more of a challenge in insertion. It is also important to identify the presence and laterality of any baclofen pumps (Medtronic, Inc., Minneapolis, MN) because they will need to be protected during the approach to the spine. Second, it is important to consider whether preoperative halo traction or intraoperative traction is needed. Patients with Cobb angles of more than 110 degrees or severe proximal thoracic curves sometimes benefit from preoperative traction. Some degrees of pelvic obliquity can be corrected with distal traction, using the skin traction method if hip or knee contractures are not too severe. Third, while extension of the fusion down to the pelvis is planned, it is equally important to consider how far cephalad to extend the fusion. As a general rule, all vertebrae within the main coronal and sagittal curves and any proximal thoracic curve larger than 30 to 35 degrees should be included in the fusion. Fourth, it is important to plan whether correction of the patient’s deformity will occur from caudad to cephalad or cephalad to caudad. Unless the patient has a severe proximal thoracic curve, correction from caudad to cephalad is preferred.