Prevalent vertebral fracture on bone density lateral spine (VFA) images in routine clinical practice predict incident fractures

Purpose: The predictive validity of vertebral fracture assessment (VFA) on bone density lateral spine images to identify prevalent vertebral fractures in routine clinical practice has not been established. Our objective was to estimate the associations of prevalent vertebral fracture identified on VFA images in routine practice with incident hip, all non-vertebral, major osteoporotic, and clinical vertebral fractures, using the Manitoba Bone Density database. Methods: From 2010 onward, 9972 men and women (mean age [SD] 76 [6.9] years) had VFA images obtained at the time of bone densitometry that were interpreted for vertebral fracture by the clinicians reading the bone density tests. Definite and possible prevalent vertebral fractures, respectively, were identified in 1575 (15.8%) and 293 (2.9%) using a modified Algorithm Based Qualitative method. We ascertained incident fractures using Manitoba provincial health databases over a mean 2.8 (SD 1.7) years and used Cox proportional hazards models to estimate the associations of prevalent vertebral fractures with incident fractures. Results: Compared to no prevalent vertebral fracture, those with definite prevalent vertebral fracture had higher hazard ratios for incident hip (HR 1.95, 95% C.I. 1.45 to 2.62), non-vertebral (HR 1.99, 95% C.I. 1.68 to 2.35), and clinical vertebral fracture (HR 2.68, 95% C.I. 1.69 to 4.23) adjusted for age, bone mineral density, body mass index, prior fracture, parental hip fracture, glucocorticoid use, alcohol use, smoking, and rheumatoid arthritis. These associations did not vary by FRAX fracture risk estimates or bone mineral density category. Conclusion: Prevalent vertebral fractures identified on densitometric VFA images in routine clinical practice are strongly associated with incident fractures, and this study is the first to show this using any lateral spine imaging modality outside of research settings. These findings are strong evidence supporting the targeted use of densitometric VFA imaging among post-menopausal women and older men referred for bone densitometry.