INTRODUCTION: Vertebral fracture (VF) is one of the causes of sagittal imbalance, a risk factor for future care needs. This study aimed to clarify the influence of VF and sagittal imbalance on the incidence of future care needs in the local community residents.
METHODS: This study was a prospective cohort study. The subjects were 65 or older and had undergone specific health examinations and standing whole-spine lateral radiographs in the community in 2010. The presence of vertebral fractures from the T4 to L5 was evaluated using the semi-quantitative quadrant (SQ) method, and grade 1 or higher was judged as having a fracture. The sagittal vertical axis (SVA) was measured as an index of sagittal imbalance, and SVA>95 mm was defined as an imbalance. The primary outcome was new long-term care needs certification during the 5 years. New long-term care certification was evaluated based on long-term care applications submitted to the Japanese national health insurance system from 2011-2015.
RESULTS: The analysis included 576 subjects (222 males and 354 females, with a mean age of 73 years). The subjects were divided into four groups according to the presence or absence of sagittal imbalance and VF: 25 (4.3%) were in the imbalance+VF group, 9 (1.5%) were in the imbalance only group, 327 (57%) were in the VF only group, and 215 (37%) were in the normal group with none of these conditions. Univariate analysis showed that the imbalance+ VF and imbalance-only group significantly showed new certified long-term care needs for five years (p<0.05). Multi-variate analyses showed the odds ratio [CI] of VF with an imbalance to VF only adjusted for age and sex was 3.8 [1.3-11.2], indicating that VF with sagittal imbalance was associated with future long-term care needs.
DISCUSSION: This study suggested that radiological VF with severe sagittal imbalance is a risk factor for future long-term care needs. Maintaining a normal sagittal alignment after vertebral fractures is more critical to prevent the need for long-term care.