Association of vertebral fractures and dynamic sagittal spinal alignment during stand-up and sit-down.

Abstract

PURPOSE: While static sagittal spinal alignment is known to be associated with vertebral fractures, the relationship between dynamic sagittal spinal alignment and vertebral fractures remains unclear. Understanding this relationship could aid in preventing vertebral fractures. This cross-sectional study aimed to examine the association between dynamic sagittal spinal alignment and vertebral fractures during the movement from standing-up to sitting-down. METHODS: Static and dynamic sagittal spinal alignments, bilateral spina malleolar distance (SMD), and the five-times-sit-to-stand test (FTSST) were measured. Dynamic alignments were assessed using a 3D motion analysis system with six infrared cameras, tracking thoraco-lumbar (T-L), lumbo-pelvic (L-P), and thoraco-pelvic (T-P) angles. Multiple logistic regression analysis was performed to identify factors influencing vertebral fractures, using age, body mass index (BMI), SMD, FTSST, static, and dynamic sagittal spinal alignments as covariates. RESULTS: Among 46 participants, 19 had vertebral fractures (fracture group) and 27 did not (non-fracture group). T-L and T-P angles were highly correlated (coefficient = 0.885), indicating multicollinearity. Two models were analyzed: one excluding T-P and the other excluding T-L. In the model excluding T-P, T-L was significantly associated with vertebral fractures (Odds = 1.114, 95% CI = 1.004–1.237). CONCLUSIONS: Dynamic sagittal spinal alignment, specifically the T-L angle, was significantly associated with vertebral fractures. These findings suggest that assessing dynamic spinal alignment during movement may provide valuable insights into vertebral fracture prevention.