Correlation between spinopelvic sagittal balance and vertebral fractures in postmenopausal women.

Objective: To investigate the relationship between spinopelvic alignment and vertebral fracture in postmenopausal women with osteoporosis. Materials and Methods: This was a retrospective cross-sectional study including 93 women diagnosed with osteopenia or osteoporosis by densitometry between June 2017 and March 2018. Using the software Surgimap to analyze lateral X-rays of the spine and pelvis, we measured the following spinopelvic parameters: pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), sagittal vertical axis (SVA), global tilt (GT), spinosacral angle (SSA), T1 pelvic angle (TPA), lumbar lordosis (LL), and thoracic kyphosis (TK). The spinopelvic parameters were assessed in relation to fracture occurrence by estimating prevalence ratios. Two groups (patients with and without fractures) were compared on the basis of their spinopelvic parameters. Vertebral fractures were graded by the Genant classification, and the spinal deformity index (SDI) was calculated as the sum of the grades. The SDI was found to correlate with spinopelvic parameters. Intraobserver and interobserver reliability for the measurement of the spinopelvic parameters was evaluated. Results: The GT correlated significantly with the presence of fractures; the incidence of fracture was found to increase by 2.1% for every 1-degree increase in the GT. The presence of fractures was not found to correlate significantly with the SS, PT, PI, LL, TK, SVA, or SSA. The GT was significantly greater in the group with fractures than in the group without fractures. The SDI correlated significantly with global sagittal balance, as measured by the GT. Conclusion: Fractures seem to be more prevalent among women with a higher GT. The SDI appears to correlate well with global sagittal balance, as assessed by the GT.