Inclusion Criteria:  Age ≥45 years old; The number of fixed vertebral bodies ≥5, and the upper instrumented vertebra (UIV) is located in the thoracolumbar segment; Third generation total pedicle screw internal fixation system; Follow-up time ≥24 months; Complete clinical and imaging data.  Exclusion Criteria:  Idiopathic scoliosis, neuromuscular scoliosis, non-structural scoliosis, spinal tumors, spinal tuberculosis, ankylosing spondylitis, humman's disease, history of spinal surgery, history of spinal trauma, and history of hip surgery