Is Trabecular bone score associated with multiple fragility fractures? Evidence from a large observational cohort study

Abstract Objectives Trabecular bone score (TBS) is a measure of bone microarchitecture associated with hip and major osteoporotic fractures. However, TBS has not been evaluated in UK-specific cohorts, and little is known about its association with multiple fragility fracture phenotypes; this study aimed to investigate these associations. Methods TBS was available in a subset of patients referred for DXA assessment in northwest England between June 2004 and May 2025. Fragility fracture phenotypes were defined as a single hip fracture (SHF), single non-hip fracture (SNHF), multiple non-hip fractures (MNHF), and multiple fractures including at least one hip fracture (MFH). These categories served as the dependent variable in a multinomial logistic regression model. Ordinal logistic regression models assessed associations with ordered hip and non-hip fracture categories. All models were adjusted for FRAX variables and the mean TBS, with multiple comparisons accounted for using Bonferroni correction. Results A total of 2,782 patients were included, with a mean age of 66.84 years (SD 12.31), mean BMI of 27.31 kg/m² (SD 5.91), and 2,146 (77.2%) were female. Lower TBS was associated with SNHF (OR 1.37, 95% CI 1.28–1.48), MNHF (OR 1.32, 95% CI 1.27–1.36), and MFH (OR 1.68, 95% CI 1.16–2.43). In ordinal models, lower TBS was associated with increasing fracture burden within the non-hip fracture groups (OR 1.31, 95% CI 1.16–1.47), but was not associated with SHF or the hip fracture groups. Conclusion TBS is associated with multiple fragility fracture phenotypes and greater fracture burden within non-hip fracture categories.