Basic and clinical evaluation of the measurement of bone resonant frequency

Ultrasound velocity, through bone predicts incident vertebral deformity

We followed 130 postmenopausal women without evidence of vertebral deformity by lateral spine radiographs on entry into study for 2 years, and repeat spine radiographs were taken at the end of that time. Incident deformities occurring within this 2 year period were detected by two methods, a level-specific radiogrammetric approach and visual inspection by skilled clinicians. Fourteen incident deformities were detected by the radiogrammetric method, and 19 by the clinicians. Ultrasound transmission velocity was measured at the patella in each subject on entry. Values for ultrasound velocity were significantly correlated with incident fracture occurrence, with individuals having velocity values more than one standard deviation below the mean for the group exhibiting from 3.3 to 4.6 times the probability of incident fracture as individuals with velocity values more than one standard deviation above the mean. Thus, low values for ultrasound transmission velocity at the patella detect yet-unexpressed bony fragility at the spine and predict future fracture.

Clinical determination of bone quality: is ultrasound an answer?

Progress in clinical characterization of bone relies on developing a means to clinically assess all of the important determinants of bone quality, specifically, the intrinsic material properties of a bone (stiffness and brittleness) versus the macroscopic structural properties [apparent mass density (g/cc), structural shape and distribution of cortical mass, trabecular architecture, extent of unrepaired microdamage, and defects associated with the accelerated remodeling in early menopause]. Ultrasound devices currently measure parameters related to either of only two basic properties: bone ultrasound attenuation (BUA) or the apparent velocity of wave propagation (AVU). Theory and repeated corroboration in the laboratory have shown that the velocity of sound in solids such as bone has a quantitative relationship to the elastic modulus (or stiffness) and mass density. Although no comparable physical model exists for BUA, growing in vitro and in vivo empirical evidence shows a relationship to stiffness and mass density as well. Therefore, the question of ultrasound's ability to provide additional, clinically useful information about bone quality reduces to this: Does bone quality depend significantly on bone stiffness and does stiffness depend on factors other than bone mass alone? Clinical study results provide mounting evidence of ultrasound's abilities. (1) Numerous studies compare either velocity or BUA with BMC or BMD. The correlation coefficients vary widely between studies, even when repeated by the same investigators and laboratories. Two studies demonstrated this by comparing groups of subjects who are indistinguishable by BMD at the lumbar spine, but whose mean AVU readings are significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

A critical review of bone mass and the risk of fractures in osteoporosis

The usefulness of various bone mineral measurement techniques is a subject of current controversy. In order to explore whether disparate conclusions may have arisen from differences in analytic methodology, data from published reports of bone mass and nonviolent fractures have been reanalyzed in terms of fracture risk. In the large majority of studies, reduced bone mass was associated with an increased risk of fractures. However, the magnitude of the relationship varied much more among cross-sectional studies than among prospective studies, suggesting that bias related to subject selection and/or postfracture bone loss may have strongly influenced the cross-sectional findings. We conclude that more emphasis should be given to the results of prospective studies, and that more attention should be paid to subject selection in all investigations. Analyzing and presenting results in terms of fracture risk would probably reduce the level of confusion in the field and provide more clinically relevant information. These issues are also applicable to studies of potential fracture risk factors other than bone mass, such as bone structure and bone quality.

Prevalence of bone demineralization in the United States

A study of the distribution and prevalence of bone demineralization in the US population is reported. Based on the HANES I Survey data that incorporated bone density examination of V-2 by the Goldsmith and Vose techniques in a national sample of 6030 adults, it was observed that (1) age-adjusted bone density differences between sexes were consistently found when controlling for race (the prevalence of low bone density was greater among females than males) and (2) whites of both sexes had higher prevalence of low density than blacks in most age-sex categories.

Bone changes and aortic calcification in aging inhabitants of mountain versus seacoast communities in the Kii Peninsula

Bone changes and aortic calcification were compared radiographically for different age groups of the inhabitants of two communities on the Kii Peninsula at the central southern tip of the Japanese mainland, one a mountainous Shichikawa village with a traditionally restricted nutritional intake and the other a seacoast village on Oshima Island with an abundant nutritional supply. Changes in the physical properties of the bone were also assessed by resonance measurement. In the mountainous village, bone loss appeared to occur more rapidly than in the seacoast village, as indicated by a significantly higher frequency of thoracic vertebral deformity and more pronounced age-bound decrease of ulnar resonant frequency. Aortic calcification was also more frequent in Shichikawa than on Oshima Island. Such differences were more evident in women than in men. The poorer nutritional intake (especially of calcium and vitamin D) of persons living in the mountainous village (which receives less sunshine) might be responsible for the accelerated age-bound degenerative changes observed in their skeletal and vascular systems.