Bidirectional axial transmission (BDAT) measurements at the one-third distal radius may be useful for characterizing cortical bone and evaluating fracture risk among postmenopausal women, according to the results of a pilot, cross-sectional study published in the Journal of Bone and Mineral Research.
The investigators sought to assess the performance of a BDAT device in differentiating between postmenopausal women with and without fractures. They obtained cortical thickness and cortical porosity estimates from a total of 201 postmenopausal women; 109 belonged to a control group without fracture (mean age, 62.6 ± 7.8 years) and 92 had ≥1 nontraumatic fractures (mean age, 68.8 ± 9.2 years). Within the fracture group, 17 participants sustained hip fractures (mean age, 66.1 ± 10.3 years), 32 sustained vertebral fractures (mean age, 72.4 ± 7.9 years), and 17 sustained wrist fractures (mean age, 67.8 ± 9.6 years). Other fracture sites included the humerus, tibia, ankle, and rib. The areal bone mineral density (aBMD) of the women was obtained with the use of dual-energy x-ray absorptiometry at the femur and spine.
Patients’ femoral aBMD correlated weakly but significantly with cortical thickness (R = 0.23; P <.001) and cortical porosity (R = 0.15; P <.05). Femoral aBMD and both ultrasound parameters (cortical porosity and cortical thickness) differed significantly between the subgroup of all nontraumatic fractures combined and the control group (P <.05).
The results of the study demonstrated that cortical porosity was discriminant for all nontraumatic fractures combined (odds ratio [OR], 1.39; area under the receiver operating characteristic curve [AUC], 0.71), for vertebral fractures (OR, 1.96; AUC, 0.84), and for wrist fractures (OR, 1.80; AUC, 0.71), whereas cortical thickness was discriminant for hip fractures only (OR, 2.01; AUC, 0.72). Additionally, a significant association was observed between increased cortical porosity and vertebral and wrist fractures when these fractures were not related to any measured aBMD variables.
BDAT variables showed comparable performance to that of aBMD neck with all types of fracture (OR, 1.48; AUC, 0.72) and to that of aBMD femur with hip fractures (OR, 2.21; AUC, 0.70).
The investigators concluded that if the results of this analysis are corroborated in prospective studies, the use of BDAT measurements may be considered beneficial for the evaluation of fracture risk among postmenopausal women. These findings open perspectives into the clinical assessment of cortical bone using a portable, nonionizing device.
Minonzio J-G, Bochud N, Vallet Q, et al. Ultrasound-based estimates of cortical bone thickness and porosity are associated with non-traumatic fractures in postmenopausal women: a pilot study [published online March 26, 2019]. J Bone Miner Res. doi:10.1002/jbmr.3733