Factors influencing vertebral collapse in osteoporotic vertebral fractures: a case–control study of symptomatic patients attended in the emergency department

Summary This study aimed to identify risk factors for the collapse of osteoporotic vertebral fractures (OVFs). We analyzed data from conventional radiography and computed tomography in patients with OVFs and found that older age and two radiological measurements were predictive for vertebral collapse. These factors can be useful for clinical practice. Purpose To identify risk factors for collapse of osteoporotic vertebral fractures (OVF) on computed tomography (CT) and conventional radiography (CR). Methods This is a retrospective case–control study including a series of patients with OVF diagnosed at the emergency department of our institution from January to September 2019. Inclusion criteria were to have standing CR and supine CT within 2 weeks after the diagnosis of OVF and a follow-up CR at 6 months or later. We evaluated different imaging measurements at the initial diagnostic examinations, including vertebral height loss, local kyphosis, vertebral density, and fracture type according to the grading systems of Genant, Sugita, Association of Osteosynthesis (AO) Spine, and the German Society for Orthopaedics and Trauma. Vertebral collapse was defined as loss of ≥ 50% of vertebral area or height. Cases and controls were defined as OVFs which collapse and do not collapse, respectively, on follow-up. Results Fifty-six patients were included in the study, with a mean age of 72.6 ± 1.2 years, including 48 women. Twenty-five (44.6%) OVFs developed collapse on follow-up. None of the fracture classification systems were found to be predictive of collapse. Multivariate analysis showed that older age, increased density ratio (≥ 2) between the fractured and non-fractured vertebral bodies, and a ≥ 6% difference in posterior vertebral height (PVH) loss between standing CR and supine CT exhibited 88% discriminative power in predicting vertebral collapse. Conclusions Age over 72.5 years, a density ratio ≥ 2 between the fractured and non-fractured vertebral bodies, and a difference equal to or higher than 6% in PVH loss between standing CR and supine CT, are risk factors for developing vertebral collapse after OVF.