Correlations Among Bone Mineral Density, Broadband Ultrasound Attenuation, Mechanical Indentation Testing, and Bone Orientation in Bovine Femoral Neck Samples

Abstract

Broadband ultrasound attenuation (BUA) of the calcaneus has been found to correlate with bone mineral density (BMD) of the femoral neck. The purpose of this study was to determine if a correlation exists among femoral neck BUA, femoral neck BMD, and incremental indent depth, a qualitative indicator of local mechanical bone strength, in bovine samples, and if this correlation is dependent upon orientation. For 12 of the bovine samples obtained, BUA was measured at the femoral neck and was followed by a BMD determination of the same area. A 19 mm diameter bicortical core containing the center of the area of interest was removed, transversely cut into 7 mm, thick disks, and tested for hardness by indent depth. For these tests, BMD was well correlated with BUA (R2 = 0.85, P < 0.001). An inversely proportional relationship with a modest correlation was found between indent depth and BMD (R2 = 0.59, P = 0.026), and indent depth and BUA (R2 = 0.57, P = 0.031). In a second set of tests involving 15 different bovine samples, a bicortical core was removed from the femoral neck. A trabecular bone cube measuring 1.5 cm on a side was removed from the center of the core. BUA and BMD measurements were made along the anterior-posterior (AP), medial-lateral (ML), and cephalic-caudal (CC) aspects of the cube. The cubes were randomly separated into three groups, cut in half perpendicular to the axis of interest, and tested for hardness by indent depth. In these tests, no significant difference was found in BMD among the three orientations of the cubes scanned (P = 0.77). In contrast, the BUA along the ML orientation of the cube was significantly greater than that along the AP orientation (P < 0.05). No significant difference was found in the incremental indent depth measurements among cube orientations (P = 0.41). In the test involving only trabecular bone, a much higher correlation between BMD and incremental indent depth was found regardless of cube orientation (R2 = 0.64, P < 0.001). The data indicate that BUA, but not BMD, is affected by trabecular orientation, and that BMD is negatively correlated with incremental indent depth.

The role of quantitative ultrasound in the assessment of bone: a review

“…QUS is in¯uenced by trabecular orientation and may thus represent`bone quality' (Glu È er et al, 1993;Stewart et al, 1994;Hans et al, 1995b;Langton et al, 1996;Njeh et al, 1996;Duquette et al, 1997), but the de®nite proof hereof is not yet available. Thus, QUS probably mainly re¯ects BMD, but many investigations indicate that QUS measures something other than bone density alone.…”

“…Studies with orthogonal measurements on cubes of bovine trabecular bone have shown that BUA and UVB (ultrasound velocity through bone) depend on trabecular orientation (Glu È er et al, 1993;Njeh et al, 1996;Duquette et al, 1997). Glu È er et al (1993) found that BUA was about 50% larger when measured along the axis of the compressive trabeculae compared with the two perpendicular axes, even though BMD was the same in all directions.…”

Alters- und geschlechtsabhängige Knochenmineraldichteverteilung und mechanische Eigenschaften des proximalen Humerus

“…Abhängigkeiten zwischen der Knochenmineraldichte und der mechanischen Festigkeit des spongiösen Knochens wurden bereits im Schenkelhals des Schweins [15], der humanen Wirbelsäule [16] und in der Metaphyse von langen Röhrenknochen [9,10] nachgewiesen. Saitoh et al [4] führten ebenso mechanische Untersuchungen in 3 Höhen des proximalen Humerus parallel zum Collum anatomicum durch und fanden die höchste Festigkeit im kranialen, dorsalen Aspekt des proximalen Humerus.…”

Quantitative ultrasound at the hand phalanges: comparison with quantitative computed tomography of the lumbar spine in postmenopausal women

“…Furthermore, the different site of measure can play an important role in the comparison of our results. According to recent studies [27,28,29] there is disparity between central and peripheral measurements. It is estimated, for example, that 20±30 % of individuals have normal US values of the calcaneus but have low axial BMD.…”