Bone Abstracts

Iisn’t uncommon to encounter patients with both a fragility fracture and only a slightly low BMD value or even normal one. Currently the DXA technology can assess information on trabecular microstructural texture supplementing the standard BMD measurement, using a new method: the trabecular bone score (TBS). In order to check TBS, BMD and their combination to discriminate patients with vertebral fracture, we scanned 946 subjects. The cohort was stratified using the WHO diagnostic T-score threshold. TBS was calculated from the same DXA acquisition and region of interests than those used for the LS BMD using TBS iNsight. Vertebral fractures were confirmed using lateral vertebral assessment software. The discriminate value of BMD, TBS (L1–L4) or both combined was assessed by ROC curve and using a reclassification index. 6.6% of the cohort, suffered from at least one vertebral fracture. Fracture group have significant lower BMD and TBS than subjects without fracture (P<0.01). Correlation between TBS and BMD is low (r=0.3).The vertebral fractured group had a higher proportion of osteoporosis diagnosis (51%), but surprisingly, 5% of them have normal BMD. In the whole cohort TBS showed a significant higher discrimination power than the BMD (TBS AUC=0.756 (0.724–0.786) vs BMD AUC=0.638 (0.603–0.672), P=0.013). TBS and BMD combination improved the discrimination AUC=0.767 (0.736–0.797). When BMD stratification is used, TBS discrimination was better for normal and osteopenic subjects (AUC=0.815 (0.747–0.871) and 0.795 (0.753–0.832) respectively) than in osteoporotic subjects (AUC=0.614 (0.541–0.684)). When reclassification index was used, the combination of 1st TBS tertile threshold and BMD −2.5 T-score threshold improved the overall subject classification by 31 and 29% in comparison with the use of BMD −2.5 T-score and 1st TBS tertile thresholds alone respectively. TBS is a useful tool for patient management in daily clinical routine. One of its main clinical add-value is clearly for normal and osteopenic subjects management.