Age-related Reference Data for Cortical and Trabecular 3D-DXA Parameters: the SEIOMM-3D-DXA Project

Abstract Purpose Osteoporosis and associated hip fractures are a major public health concern. Dualenergy X-ray Absorptiometry (DXA) remains the diagnostic gold standard, but its areal (a) bone mineral density (BMD) measurements have limited sensitivity, as many fractures occur at T-scores above −2.5. Three-dimensional (3D) DXA provides compartment-specific volumetric parameters of the hip, potentially improving osteoporosis management. This study aimed to establish reference data for 3D-DXA parameters to improve osteoporosis management and investigate potential compartmental imbalances at the hip. Method This multicenter, cross-sectional, population-based observational study (SEIOMM-3D-DXA project), supported by the Spanish Society for Bone and Mineral Metabolism (SEIOMM), analyzed hip DXA scans from 1366 Spanish men and women across six centers. 3D-DXA analyses were conducted using the 3D-Shaper software (3D-Shaper Medical, Barcelona, Spain), producing estimates of trabecular volumetric (v) BMD and cortical surface (s) BMD. Age- and sex-specific reference curves were generated using the LMS method, and thresholds were established based on regression with T-score values. Moreover, trabecular vBMD and cortical sBMD Z-scores were calculated to evaluate potential compartmental imbalances. Results The derived aBMD curves closely aligned with the NHANES III Caucasian reference. Sex-specific thresholds for trabecular vBMD and cortical sBMD were established for patient stratification. Z-score comparisons revealed significant discrepancies between trabecular and cortical compartments in 52.0% of females and 48.7% of males, underlining the importance of compartment-specific bone assessment. Conclusions This study establishes reference curves for clinical interpretation of 3D-DXA parameters and demonstrates the potential of 3D-DXA to capture compartmental imbalances at the hip. Mini Abstract In this study, hip scans from over a thousand men and women in Spain were analyzed to create normative reference values for 3D-DXA parameters. These results can help doctors better stratify people based on the status of each part of the bone and improve the management of osteoporosis.