Possible factors associated with sagittal malalignment recurrence after pedicle subtraction osteotomy

Purpose This retrospective study investigates sagittal alignment after pedicle subtraction osteotomy (PSO). The purpose was to investigate factors associated with malalignment recurrence. Methods Full spine radiographs were analyzed in 66 patients (average age 54.5 years, follow-up 3.8 years). Measurements were taken preoperatively, 3 months postoperatively, at follow-up: SVA C2 and C7, C2–C7 lordosis, T4–T12 kyphosis, L1–S1 lordosis, PSO lordosis, pelvic incidence, pelvic tilt, sacral slope. Follow-up CTs were screened for pseudarthrosis and gas in sacroiliac joints. Results PSO lordosis increased from 11.8° to 40.8° ( p