Comparison of the Right and Left Femur Bone Mineral Densities in Postmenopausal Women.

Abstract

Bone mineral density (BMD) is measured in the hip and posteroanterior spine; moreover, according to the 2019 International Society for Clinical Densitometry guidelines, unilateral hip can be used. This study aimed to determine whether there is a difference between the BMD of both the femurs in postmenopausal women. A total of 343 postmenopausal women were enrolled in this study from January 1, 2010, to December 31, 2019 at a single tertiary hospital. By using the Hologic® Horizon W DXA System, the femur and spine BMD was measured; BMD was recorded in g/cm². Following regions were analyzed in both the femurs: the femur neck, the trochanter area, and total femur. Mean age at imaging was 62 ± 9.7 years, and significant difference in the total BMD of both the femurs (P = 0.003) was observed. In secondary analysis, patients with osteoporosis showed significant contralateral BMD discrepancies in trochanter and total proximal femur BMD (P = 0.041 and P = 0.011, respectively). However, in women with normal BMD, no significant difference between the right and left femur BMD was observed. Furthermore, measurement of solely the unilateral hip can lead to a 16.9% of underdiagnosis in postmenopausal women. In conclusion, it is necessary to check BMD in both hips, particularly in patients suspected of osteoporosis.