Factors associated with long-term patient-reported outcomes after three-column osteotomies

Background context Studies have demonstrated sustained improvements in patient-reported outcomes (PROs) after three-column osteotomies (three-COs), but no study has evaluated what factors impact long-term outcomes. Purpose The aim was to investigate factors associated with PROs in patients who underwent three-CO at minimum 5 years postoperatively. Study design/sample This was a retrospective review of prospective database. Patient sample All patients who had a three-CO at a single institution and completed clinical evaluations after at least 5 years postoperative were included. Outcome measures Oswestry Disability Index (ODI), Scoliosis Research Society (SRS) scores, and radiographic parameters were assessed at baseline and a minimum 5 years postoperatively. Methods Analysis of 120 patients who underwent three-CO (96-pedicle subtraction osteotomy/24-vertebral column resection) was performed. The mean age was 48 years (range 8-79), and clinical follow-up was 7 years (range 5-14). Separate multivariable linear regression analyses were performed to determine factors associated with ODI, SRS average, and SRS satisfaction while controlling for time since surgery and baseline outcome scores. Results Average PROs were significantly improved from baseline at a minimum 5-year follow-up (ODI: 48-28, p<.01; SRS: 2.8-3.5, p<.01). The average SRS satisfaction score was 4.0. Average sagittal alignment (C7 plumb) improved 74 mm, with 81% of patients' alignment less than 95 mm. Major surgical complications occurred in 32 patients (27%) with major reoperations in 30 patients (25%). Multivariable regression analysis found that prior surgery and major reoperations were risk factors for worse ODI scores. A diagnosis of adult idiopathic scoliosis and final sagittal alignment less than 95 mm were associated with improved SRS scores. Improvement in major coronal Cobb and final pelvic tilt less than 30° were associated with increased SRS satisfaction. Conclusions With a minimum 5-year follow-up, PROs in patients undergoing three-CO were associated with improvements in radiographic alignment but negatively affected by prior surgery and complications necessitating revision surgery.