Inclusion Criteria:  Underwent posterior surgery for degenerative scoliosis; Above the age of 45; Satisfy at least one of the following criteria: cobb angle > 10°, sagittal vertical axis > 5cm, pelvic tilt > 25°, or thoracic kyphosis > 60°.  Exclusion Criteria:  Underwent posterior surgery for lumbar spinal stenosis; Above the age of 45; Diagnosis of lumbar spinal stenosis.