Prevalence and Predictors of Silent Vertebral Compression Fractures: A Cross-Sectional Population-Based Study Using UK Biobank Imaging Data

Abstract Objectives: To estimate the prevalence of silent vertebral compression fractures (VCF) in an asymptomatic population and to assess the demographic and clinical predictors using data from the UK Biobank. Design: A cross-sectional study using artificial intelligence-assisted six-point morphometry of dual-energy x-ray absorptiometry spine images. Setting: UK Biobank imaging study at Stockport clinical research facility. Participants: 2,446 asymptomatic volunteers aged 40 to 79 years with no history of spinal trauma or vertebral fracture. Main outcome measures: VCFs were defined as greater than or equal to 20 percent height loss, measured by artificial intelligence, with manual correction of annotations and confirmation by a musculoskeletal radiologist. Association with age, sex, bone mineral density, body mass index, and back pain were analyzed. Results: Of 2,446 participants, 763 (31.1 percent) had at least one vertebra with greater than 20 percent height loss. Fracture prevalence increased with age: 26.8 percent (37 of 138) in those aged 40-49 years, 26.1 percent (196 of 752) at 50-59 years, 33.0 percent (380 of 1,153) at 60-69 years, and 37.2 percent (150 of 403) at 70-79 years. Excluding mild deformities, 18 percent of those aged 40-49 years had moderate or severe fractures (greater than 25 percent height loss). Fractures were 11.5 percent more common in men than in women. Age was a significant predictor, but bone mineral density (BMD) and body mass index (BMI) were not. Predictive models showed limited performance (sensitivity 44.4 percent, specificity 68.2 percent). Interobserver agreement was substantial (Fleiss kappa = 0.74). Conclusions: Silent VCFs are frequent by midlife, including among younger adults with normal bone density. Men are affected more often than women, and conventional risk factors inadequately identify those at risk. Earlier detection through opportunistic or population imaging may enable timely intervention and inform future screening and fracture-prevention strategies.