2021 Volume 12 Issue 5 Pages 759-765
Introduction: Spinal sagittal imbalance is reported to be associated with a decline in patients' quality of life; however, the cause of its progression has not been investigated. The purpose of this study was to clarify the characteristics of elderly patients with deteriorating spinal sagittal imbalance over a 2-year period.
Methods: A total of 321 participants (133 males and 188 females; mean age 72.9±4.9 years) from the Shiraniwa study were included in this analysis. Based on the SVA measured from whole spine radiographs, we classified the participants into the following three groups: SVA≤40 mm, 40 mm<SVA≤95 mm, and SVA>95 mm. Participants who showed disease progression from the first year to the third year were defined as the deteriorating spinal sagittal imbalance (DSI) group.
We compared the following items between DSI and non-DSI groups: the incidence of prevalent vertebral fractures, disc degeneration, and back muscle strength; locomotive syndrome (LS) stage 2; and sarcopenia. Using multiple logistic regression analysis, we investigated the predictors for DSI. Moreover, body composition measured using a bio-impedance analysis machine (BIA) was compared between the two groups.
Results: Overall, 45 (14.0%) participants were classified into the DSI group. The prevalence of LS stage 2 was significantly higher in the DSI group than in the non-DSI group (55.6% vs. 28.0%; p<0.01). LS stage 2 was an independent predictor of DSI with an adjusted odds ratio of 2.35 (95% CI: 1.08-5.12). Regarding the body composition measured by BIA, the ratio of trunk muscle to trunk weight percentage was significantly lower in the DSI group (male: 74.1%/78.2%, p=0.02; women: 63.7%/70.9%, p<0.01).
Conclusions: LS stage 2 was an independent predictor of deteriorating spinal sagittal imbalance over a 2-year period. Elderly patients with deteriorating spinal sagittal imbalance showed a significantly lower ratio of trunk muscle to trunk weight percentage.
