Women with fracture, unidentified by FRAX, but identified by cortical porosity, have a set of characteristics that contribute to their increased fracture risk beyond high FRAX score and high cortical porosity

摘要

The Fracture Risk Assessment Tool (FRAX) is widely used to identify individuals at increased risk for fracture. However, cortical porosity is associated with risk for fracture independent of FRAX and is reported to improve the net reclassification of fracture cases. We wanted to test the hypothesis that women with fracture who are unidentified by high FRAX score, but identified by high cortical porosity, have a set of characteristics that contribute to their fracture risk beyond high FRAX score and high cortical porosity. We quantified FRAX score with femoral neck areal bone mineral density (FN aBMD), and femoral subtrochanteric architecture, in 211 postmenopausal women aged 54–94?years with non-vertebral fractures, and 232 fracture-free controls in Troms?, Norway, using StrAx software. Of 211 fracture cases, FRAX score?>?20% identified 53 women (sensitivity 25.1% and specificity 93.5%), while cortical porosity cut-off >?80th percentile identified 61 women (sensitivity 28.9% and specificity 87.9%). The 43 (20.4%) additional fracture cases identified by high cortical porosity alone, had lower FRAX score (12.3 vs. 26.2%) than those identified by FRAX alone, they were younger, had higher FN aBMD (806 vs. 738?mg/cm2), and fewer had a prior fracture (23.3 vs. 62.9%), allp?