Cortical pore size distribution and viscoelastic tibia properties discriminate fragility fractures independent of bone mineral density

Osteoporosis is a disorder of bone remodeling leading to reduced bone mass, structural deterioration, and increased bone fragility. The established diagnosis is based on the measurement of areal bone mineral density by dual energy x-ray absorptiometry (DXA), which poorly captures individual bone loss and structural decay. Enlarged cortical pores in the tibia have been proposed to indicate structural deterioration and reduced bone strength in the hip. Here, we report for the first time the in-vivo assessment of the cortical pore size distribution together with viscoelastic bone properties by means of a novel ultrasonic cortical backscatter (CortBS) technology to discriminate between fractured and nonfractured postmenopausal women (N = 55). The discrimination performance was benchmarked with DXA and high-resolution peripheral computed tomography (HR-pQCT). The results suggest a superior discrimination performance of CortBS (area under the receiver operating characteristic curve: 0.69 ≤ AUC ≤ 0.75) compared to DXA (0.53 ≤ AUC ≤ 0.55) and a similar performance compared to HR-pQCT (0.68 ≤ AUC ≤ 0.73).