Corrective Long Spinal Fusion to the Ilium for Patients with Adult Spinal Deformity Results in Good Physical Function after Mid- to Long-Term Postoperative Follow-Up.

Introduction: This study investigated the mid- to long-term postoperative outcomes of patients with adult spinal deformity (ASD), focusing on physical function and quality of life (QOL). We also compared age-related changes between patients aged 75 years or older (high elderly) and those younger than 75 years (low elderly). Methods: A total of 47 patients with ASD underwent thoracic-iliac long spinal fusion between August 2013 and September 2014. The study spanned from the preoperative period to at least 5 years postoperatively. Physical function was assessed using isometric hip flexion and knee extension muscle strength, the 6-min walk distance test, the 10-m walk test, and the timed up and go test. QOL was assessed using the Scoliosis Research Society-22 and Oswestry Disability Index. Repeated-measures analysis of variance with a mixed model approach, corrected for multiple comparisons using Bonferroni, was performed. Results: Of the 47 patients, 21 participated in the study. Patients with ASD showed improved gait ability postoperatively. Hip flexor strength decreased at more than 5 years postoperatively compared with the preoperative strength. Patient-reported outcome (PRO) scores showed continuous improvement postoperatively, regardless of age. Although older patients had lower preoperative and postoperative physical function, their PRO scores significantly improved and remained favorable for more than 5 years postoperatively. Conclusions: Patients with ASD experienced sustained improvements in walking ability and PRO for more than 5 years postoperatively. The results of this study showed that even among the elderly, PRO scores consistently improved after surgery and remained positive for an extended period.