Methods: Volunteers over 50 years of age underwent radiographic analysis. Radiographic parameters including pelvic tilt (PT), pelvic incidence (PI), lumbar lordosis (LL), thoracic kyphosis, and sagittal vertical axis (SVA) were measured. The the three Scoliosis Research Society-Schwab sagittal modifiers (PT, SVA, PI–LL) were categorized and the KL grade was assessed. Differences in spinopelvic parameters and Oswestry Disability Index (ODI) scores among KL grades were evaluated. Results: A total of 396 volunteers (160 men, 236 women; mean age, 74.4 years) were analyzed. PI–LL and PT in KL4 were significantly higher compared to that in the other KL grades. However, there were no significant group differences in SVA. In women, but not in men, higher frequencies of the worst modifier grade (++) were observed for PI–LL and PT in the KL3 and KL4 groups compared to those for the other KL grades. In women, the ODI score in KL4 was worse compared to that in the other KL grades. Conclusions Individuals over 50 years of age with severe knee osteoarthritis had poor lumbo-pelvic sagittal alignment. Moreover, the progression severity of knee osteoarthritis had more impact onstronger relationship with lumbo-pelvic malalignment and disability-related low back pain in women than in men.

Objectives: Locomotive syndrome stage 3 (LS3), which has been established recently, may imply a greater need for care than LS stage 0 (LS0), LS stage 1 (LS1), and LS stage 2 (LS2). The relationship between LS3 and long-term care in Japan is unclear. Therefore, this study aimed to examine this relationship. Methods: A total of 531 patients (314 women and 217 men; mean age, 75 years) who were not classified as requiring long-term care and underwent musculoskeletal examinations in 2012 were grouped according to their LS stage. Group L comprised patients with LS3 and Group N comprised those with LS0, LS1, and LS2. We compared these groups according to their epidemiology results and long-term care requirements from 2013 to 2018. Results: Fifty-nine patients (11.1%) were diagnosed with LS3. Group L comprised more patients (50.8%) who required long-term care than Group N (17.8%) (P < 0.001). Group L also comprised more patients with vertebral fractures and knee osteoarthritis than Group N (33.9% vs 19.5% [P = 0.011] and 78% vs 56.4% [P < 0.001], respectively). A Cox proportional hazards model and Kaplan–Meier analysis revealed a significant difference in the need for nursing care between Groups L and N (log-rank test, P < 0.001; hazard ratio, 2.236; 95% confidence interval, 1.451–3.447). Conclusions Between 2012 and 2018, 50% of patients with LS3 required nursing care. Therefore, LS3 is a highrisk condition that necessitates interventions. Approaches to vertebral fractures and osteoarthritis of the knee could be key.