Objective: To determine the ability of measurements of bone density in women to predict later fractures. Design: Meta-analysis of prospective cohort studies published between 1985 and end of 1994 with a baseline measurement of bone density in women and subsequent follow up for fractures. For comparative purposes, we also reviewed case control studies of hip fractures published between 1990 and 1994. Subjects: Eleven separate study populations with about 90000 person years of observation time and over 2000 fractures. Main outcome measures: Relative risk of fracture for a decrease in bone mineral density of one standard deviation below age adjusted mean. Results: All measuring sites had similar predictive abilities (relative risk 1.5 (95% confidence interval 1.4 to 1.6)) for decrease in bone mineral density except for measurement at spine for predicting vertebral fractures (relative risk 2.3 (1.9 to 2.8)) and measurement at hip for hip fractures (2.6 (2.0 to 3.5)). These results are in accordance with results of case-control studies. Predictive ability of decrease in bone mass was roughly similar to (or, for hip or spine measurements, better than) that of a 1 SD increase in blood pressure for stroke and better than a 1 SD increase in serum cholesterol concentration for cardiovascular disease. Conclusions: Measurements of bone mineral density can predict fracture risk but cannot identify individuals who will have a fracture. We do not recommend a programme of screening menopausal women for osteoporosis by measuring bone density. Key messages Measuring bone mineral density has been suggested as a method of identifying individuals at high risk of fracture in a preventive context Our meta-analysis of prospective studies showed that all studies measuring bone density at any site had similar predictive ability for a decrease of 1 SD in bone density except for measurements at hip and spine, which have better predictive ability for fractures in hip and spine respectively Predictive ability of decrease in bone mass was roughly similar to (or, for hip or spine measurements, better than) that of a 1 SD increase in blood pressure for stroke and better than a 1 SD increase in serum cholesterol concentration for cardiovascular disease Although bone mineral density measurements can predict fracture risk, they cannot identify individuals who will have a fracture, and a screening programme for osteoporosis cannot be recommended

Meta-analysis of how well measures of bone mineral density predict occurrence of osteoporotic fractures

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(02)08761-5.pdf

Diagnosis of osteoporosis and assessment of fracture risk

This paper reviews the theory and applications of photoacoustic (also called optoacoustic) methods belonging to the more general area of photothermal measurement techniques. The theory covers excitation of gaseous or condensed samples with modulated continuous light beams or pulsed light beams. The applications of photoacoustic methods include spectroscopy, monitoring deexcitation processes, probing physical properties of materials, and generating mechanical motions. Several other related photothermal methods, as well as particle-acoustics and wave-acoustics methods are also described. This review complements an earlier and narrower review [Rev. Mod. Phys. 53, 517 (1981)] that is mainly concerned with sensitive detection by pulsed photoacoustic spectroscopy in condensed matter.

Applications of photoacoustic sensing techniques

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(95)11456-4.pdf

Ultrasonographic heel measurements to predict hip fracture in elderly women: the EPIDOS prospective study.

96153999 Meta-analysis of how well measures of bone mineral density predict occurrence of osteoporotic fractures

We have carried out measurements of the frequency dependence of ultrasonic attenuation in the range 0.2–1 MHz in in vitro samples of bovine cancellous bone and in vivo os calcis heel bones. A comparison of the results allows us to infer that the in vivo measurements are dependent on the bone mineral content of the os calcis. The bone mineral content has been determined in this way for three female populations and indicates that the technique allows determination of bone loss and the study of the onset and progress of osteoporosis. The technique has the great advantage of health safety over radiographic and neutron activation analysis. It may also prove to be more sensitive to small changes in bone mineral content.

/pdf/the-measurement-of-broadband-ultrasonic-attenuation-in-23sjapo82g.pdf

The measurement of broadband ultrasonic attenuation in cancellous bone.

The laser generation of ultrasound in solids is reviewed with particular emphasis on the application of this unique ultrasonic source. Three regimes for the generation of ultrasound in solids using lasers in the visible near infrared wavelength region exist: thermoelastic, plasma and constrained surface source regimes. The mechanism for ultrasonic generation in each of these regimes is given. Recent experimental investigations into laser-generated ultrasound are also described, including a description of a different mechanism for the generation of ultrasound in solids using a CO2 laser. Finally, the many applications of laser-generated ultrasound are reviewed. These applications range from nondestructive testing to the determination of candle flame parameters. Possible future applications are also outlined.

https://iopscience.iop.org/article/10.1088/0022-3727/26/3/001/pdf

Laser-generated ultrasound: its properties, mechanisms and multifarious applications

OBJECTIVE--To assess the relative importance of osteoporosis of the os calcis, cognisance, and mobility in the risk of subsequent fracture of the hip in elderly women. DESIGN--Prospective study of elderly women in residential care over two years. SETTING--21 Private or 38 local authority residential homes for the elderly and 4 geriatric hospitals in Doncaster and Hull. SUBJECTS--1414 Ambulant women aged over 69, in private or local authority residential care or geriatric care. Those who had had bilateral hip surgery were excluded. MAIN OUTCOME MEASURES--Broad band ultrasonic attenuation (BUA) index, Clifton assessment procedures for the elderly test (for cognisance), and mobility on a six point scale, and fracture of the hip in the subsequent two year period. RESULTS--73 Women fractured their hip during the two years. Their mean age was not significantly different from that of the women who did not have a fracture (85.3 (SD 5.6) v 83.9 (6.3); p = 0.07), but their mean BUA index (40.3 (19.3) v 50.9 (22.2) db/MH2), and score for cognisance (median 19 (interquartile range 10.5-27.0) v 24 (17-30)) were significantly lower (both p less than 0.001). These variables had independent associations with fracture of the hip. Women with fractures had a significantly lower score for the psychomotor component of the cognisance test (4.5 (1-8) v 7 (2-10); p less than 0.0025 and were significantly more mobile (1(1-3) v 3 (1-6); p less than 0.02). Subdividing women according to high, medium, and low scores for BUA index and cognisance testing disclosed a high risk group (118 women) with low BUA index and cognisance score, whose incidence of fracture was 12.8%; in the group at lowest risk (136 women) with high BUA index and cognisance score, the incidence of fracture was only 1.5% (relative risk 8.4 (95% confidence interval -2.0 to 35.5]. Further analysis showed that those most at risk were, additionally, most mobile but that less mobile women with good cognisance had a low incidence of fractures, regardless of the BUA index, (1.2%, high index, v 0.9%, low index). CONCLUSIONS--Elderly women most at risk of sustaining hip fractures were those with low BUA index, low cognisance test score, and high mobility. Improving bone strength and cognisance in elderly women may reduce their incidence of hip fracture.

https://www.bmj.com/content/bmj/301/6753/638.full.pdf

Prediction of hip fracture in elderly women: a prospective study.

Quantitative experimental measurements have been made in the study of thermoelastic generation of elastic waves in a metal by unfocused laser radiation. A calibrated wide‐band detection system, incorporating a capacitance transducer, has enabled acoustic waveforms to be recorded with a minimum of distortion. From these measurements, a theoretical model has been developed. The transfer function of the metal block has been deconvoluted to give the acoustic source function, which was modeled as a rapidly expanding point volume of material. The thermoelastic source generated longitudinal (L) and (S) waves, but the latter predominated at the epicenter, where, in experiments presented here, both wave amplitudes L and S were proportional to the total absorbed energy in the laser pulse.

Quantitative studies of thermally generated elastic waves in laser‐irradiated metals

The generation of acoustic waves in metals by pulsed laser irradiation over a wide range of material conditions has been studied. Capacitance transducers have been used to obtain quantitative measurements of the amplitude of bulk acoustic waveforms where the laser beam was directed onto free metal surfaces in the presence and absence of surface plasmas, and onto modified metal surfaces. The application of acoustic wave propagation theory has allowed theoretical waveforms to be determined. By combining data for thermoelastic and normal force sources, waveforms have been produced that follow closely those measured experimentally.

S.B. Palmer

Papers

The measurement of broadband ultrasonic attenuation in cancellous bone.

Laser-generated ultrasound: its properties, mechanisms and multifarious applications

Prediction of hip fracture in elderly women: a prospective study.

Quantitative studies of thermally generated elastic waves in laser‐irradiated metals

Quantitative measurements of laser-generated acoustic waveforms