Impact of Lumbar Arthrodesis on Activities of Daily Living in Japanese Patients with Adult Spinal Deformity Using a Novel Questionnaire Focused on Oriental Lifestyle

<b>Background/Objectives:</b> Correction surgery for adult spinal deformity (ASD) reduces disability but may lead to spinal stiffness. Cultural diversity may also influence how this stiffness affects daily life. We aimed to evaluate the impact of correction surgery on Japanese patients with ASD using a newly developed questionnaire and to clarify how these patients adapt to their living environment postoperatively in response to spinal stiffness. <b>Methods:</b> This retrospective study included 74 Japanese patients with operative ASD (mean age: 68.2 ± 7.5 years; fusion involving >5 levels) with a minimum follow-up of 1 year. Difficulties in performing various activities of daily living (ADLs) were assessed using a novel 20-item questionnaire tailored to the Oriental lifestyle. The questionnaire also evaluated lifestyle and environmental changes after surgery. Sagittal and coronal spinal parameters were measured using whole-spine radiographs, and clinical outcomes were assessed using the ODI and SRS-22 scores. <b>Results:</b> Coronal and sagittal alignment significantly improved postoperatively. Although the total ADL score remained unchanged, four trunk-bending activities showed significant deterioration. The lower instrumented vertebrae level and pelvic fusion were associated with lower scores in 11 items closely related to trunk bending or the Oriental lifestyle. After surgery, 61% of patients switched from a Japanese-style mattress to a bed, and 72% swapped their low dining table for one with chairs. Both the ODI and SRS-22 scores showed significant postoperative improvements. <b>Conclusions:</b> Trunk-bending activities worsened postoperatively in Japanese patients with ASD, especially those who underwent pelvic fusion. Additionally, patients often modified their living environment after surgery to accommodate spinal stiffness.