Comparison of three plain radiography methods for evaluating proximal humerus bone strength in women

Abstract

BackgroundWe assessed the correlation between three methods for measuring cortical thickness of the humerus on a plain radiograph and bone mineral density measured by dual-energy X-ray absorptiometry in order to establish a simple bone strength evaluation method in patients at risk of proximal humerus fragility fracture. MethodsIn this retrospective study, 1732 patients underwent screening of the distal third radius, proximal femur, and lumbar spine by dual-energy X-ray absorptiometry. We identified 224 patients who also underwent anteroposterior shoulder radiography. Patients with fractures or who had undergone surgery in the region of interest were excluded. The study consisted of 80 women with a mean age of 76 years (range: 39–94 years). Cortical thickness, cortical index, and deltoid tuberosity index were determined to assess the proximal humerus. Correlation between bone mineral density measured by dual-energy X-ray absorptiometry and cortical thickness determined using these three methods was examined. We defined the osteoporosis group as patients satisfying both the World Health Organization criteria and the diagnostic criteria for primary osteoporosis (2012 revision) and compared values between the osteoporotic and non-osteoporotic groups. ResultsBMD correlated positively with cortical thickness, cortical index, and deltoid tuberosity index values, but the strength of correlation differed. These values were significantly lower in the osteoporotic group than in the non-osteoporotic group. Receiver operating characteristic curve analysis revealed that only the distal third radius had an area under the curve of 0.7 or more for all methods. ConclusionsAll three methods yielded values that correlated with the dual-energy X-ray absorptiometry bone mineral density measured at the distal third radius, the proximal femur, and the lumbar spine. The correlation coefficient in the radius was high and differed significantly from those of weight-bearing bones (proximal femur, lumbar spine).