New Trabecular Bone Score Reference Values for Children and Adolescents According to Age and Sex and Their Relationship with Body Size and Fracture Incidence

Abstract Trabecular bone score (TBS) is a textural index derived from lumbar spine (LS) DXA images that provides an indirect measure of trabecular microarchitecture. We published the first pediatric TBS reference dataset in 2022. The TBS software algorithm was subsequently modified by the manufacturer to improve soft-tissue thickness correction and precision. In this study, we aimed to develop new pediatric TBS reference ranges using the updated TBS Insight v4.0 software, determine if these differed from those previously published, and investigate the associations between TBS, age, sex, anthropometrics, and incident fracture in healthy children. TBS data from 9898 LS scans in healthy US children from the Bone Mineral Density in Childhood Study were used to generate reference ranges for youth 5-20 years by age and sex. The new TBS L1-L4 reference ranges differed from those generated using the prior software version, overall mean TBS L1-L4 1.35 ± 0.10 vs 1.33 ± 0.12, p<0.0001. Precision was numerically improved; percent coefficient of variation of 2.43% (95%CI: 2.18,2.74) compared to 2.87% (95%CI: 2.58,3.23). TBS values increased with age and differed by sex. There were nonlinear associations between TBS Z-scores and height- and BMI Z-scores, peaking at r=0.43 at 12 years in females and 0.34 at 14 years in males for height, and r=0.38 at 15 years in females and 0.31 at 15 years in males for BMI (p<0.0001 for all). TBS Z-scores were not associated with risk of incident low-to-moderate impact fracture over 6 years (hazard ratio 0.97, 95%CI:0.84,1.12). In summary, the new pediatric TBS reference ranges differed from those previously published and should be used for scans obtained using TBS Insight v4.0 software. TBS values increased during childhood and were associated with height and BMI but not incident fracture in this cohort of healthy children. Future studies of TBS in children at risk of skeletal fragility are needed.