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PubMed1983

Quantitative assessment of bone density on X-ray picture.

On an X-ray picture of the hands along with an aluminum step-wedge, the bone density was measured at the middle site of the metacarpal bone II with a densitometer and a computer to provide 6 indices in healthy subjects and patients with osteoporosis in order to assess the degree of bone density. This method was observed to exhibit significant correlations with the already established methods for bone mineral assessment including the Jikei method, photon absorptiometry, and bone biopsy. Thus our method permits the assessment of the degree of bone atrophy.

Absorptiometry, Photon↗

PubMed1995

Long-term changes in bone mineral density following total knee replacement.

Bone density was measured using dual photon absorptiometry and dual xray absorptiometry below the tibial component under the medial and lateral plateaus, under the central peg, and distal to the central peg. Measurements of bone density were taken at 1 week, 6 weeks, 6 months, and 1 year after surgery in 31 patients. Seven of these patients also had measurements taken 8 years after surgery. The average age of the patients at surgery was 69 years old. One week after surgery, the mean bone density from all regions was 0.77 g/cm2 in women compared with 1.14 g/cm2 in men. Between 6 weeks and 6 months, the bone density below the tibial component declined inconsistently in most patients, but by 1 year the bone mineral density was statistically equal to the initial bone density at 1 week after surgery. Eight years after total knee arthroplasty, there was a 36.4% decrease in bone mineral density between men and women was not statistically significant. Medial plateau, lateral plateau, under the peg, and distal to the peg bone density changes tended to be the same. Maximum rates of bone resorption in patients with osteoporosis of the same age group have been reported to be between 1% and 2% per year. In this study, after an initial stable period, the bone density of the proximal tibia beneath the tibial component consistently decreased at a rate of 5% per year. Surgeons must consider this relatively large decrease in bone density if they are relying on bone for long-term stable fixation of the prosthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

PubMedDate not supplied

[Pre-therapeutic management and surveillance of menopausal hormone replacement therapy].

Pre-therapeutic evaluation of menopausal hormone replacement therapy (HRT) requires certain measures in addition to a standard gynecological assessment. It is important to identify any possible breast or endometrial disorder which might require specific treatment or an adjustment of standard HRT. Skeletal status is assessed by history and, if necessary, by double-photon absorptiometry. Following such evaluation, absolute contra-indications are few in number, by virtue of the use of natural estradiol and non-androgenic progestogens. They essentially concern breast cancer and a thrombo-embolic history. The first follow-up visit, at three months, enables confirmation of the acceptability and efficacy of treatment and its adjustment if required. A monitoring calendar is then suggested.

Absorptiometry, Photon↗

PubMed1995

Long-term bone loss after renal transplantation: comparison of immunosuppressive regimens.

Serial measurements of serum and urine markers of bone metabolism and of forearm bone density (BMD) by dual photon absorptiometry were performed in 22 patients undergoing renal transplantation in 1986. Patients were randomised to immunosuppression with (1) cyclosporin alone (CsA group, n = 10), (2) cyclosporin for 3 months followed by azathioprine-prednisone (CsA/AzP group, n = 3) or (3) long-term azathioprine-prednisone (LT AzP group, n = 9). As no reduction in bone mineral density (BMD) was noted in the first 6 months, groups 2 and 3 were considered together (AzP group, n = 12). Mean +/- SEM BMD fell by 19 +/- 2% at 36 months (n = 19, p < 0.01), with similar reductions seen in the CsA and AzP groups. At 60 months, BMD of the AzP group was 25 +/- 3% below baseline (p < 0.01), while the CsA group were only 5 +/- 4% below baseline (p = NS vs baseline, p < 0.05 vs AzP group). The degree of reduction in BMD over 5 years correlated with total glucocorticoid dose (r = 0.63, p < 0.05), but not with biochemical markers of bone turnover. Serum alkaline phosphatase fell post-transplant in patients treated with AzP, but not in the CsA group. These results demonstrate significant loss of forearm bone mineral with long-term follow-up after renal transplantation, but suggest that patients treated with cyclosporin monotherapy may be at lower risk of this complication.

Absorptiometry, Photon↗

PubMed1994

Bone characterization with ultrasound: state of the art and new proposal.

Ultrasound transmission measurement through the os calcis is an emerging technique and a promising clinical tool for early assessment of osteoporosis. In this paper we first present a short discussion on the physical meaning of ultrasound velocity and attenuation, the methods of measurements and the potential contribution of ultrasound compared to photon absorptiometry. After analysing the various results in vivo published up to now we shall present some new perspectives of ultrasonic bone characterization: broadband ultrasonic attenuation imaging (BUAI) and pulse-echo measurement.

Absorptiometry, Photon↗

PubMedDate not supplied

[Current methods and equipment in densitometry of the bone tissue].

In the past 15 years there has been an intensive development of methods and equipment for non-invasive quantitative determination of the mineral status of the human skeleton in the USA and some Western European countries. The specialized osseous densitometers which are based on photon absorptiometry and which use various radionuclides or an X-ray tube as a source of radiation have extensively spread.

Absorptiometry, Photon↗

PubMed1994

Thyroid hormone use and bone mineral density in elderly women. Effects of estrogen.

OBJECTIVE: To determine the effect of long-term use of thyroid hormone on bone mineral density (BMD) in elderly women and the potential mitigating effects of estrogen replacement therapy. DESIGN: Cross-sectional, community-based study. SETTING: Rancho Bernardo, Calif. PARTICIPANTS: A total of 991 white women aged 50 to 98 years who participated in a study of osteoporosis. MAIN OUTCOME MEASURES: Bone mineral density at the ultradistal radius and midshaft radius using single-photon absorptiometry and at the hip and lumbar spine using dual-energy x-ray absorptiometry. RESULTS: A total of 196 women taking thyroid hormone for a mean duration of 20.4 years were compared with 795 women who were not using thyroid hormone. Women taking daily thyroxine-equivalent doses of 200 micrograms or more had significantly lower BMD levels at the midshaft radius and hip compared with those taking less than 200 micrograms. Daily doses of 1.6 micrograms/kg and greater were associated with lower bone mass at all four sites compared with nonuse, whereas doses less than 1.6 micrograms/kg were not associated with lower BMD levels. These associations were independent of age, body mass index, smoking status, and use of thiazides, corticosteroids, and estrogen. Women taking both estrogen and a thyroid hormone dose of 1.6 micrograms/kg or greater had significantly higher BMD levels at all four sites than women taking the same thyroid hormone dose alone. Women taking both thyroid hormone and estrogen had BMD levels comparable with those observed in women taking only estrogen. CONCLUSIONS: Long-term thyroid hormone use at thyroxine-equivalent doses of 1.6 micrograms/kg or greater was associated with significant osteopenia at the ultradistal radius, midshaft radius, hip, and lumbar spine. Estrogen use appears to negate thyroid hormone-associated loss of bone density in postmenopausal women.

Absorptiometry, Photon↗

PubMed1994

Bone disease in calcium stone forming patients.

The association between idiopathic hypercalciuria and osteopenia (OP) has been recently recognized. It is not established whether or not calcium intake plays a critical role in the loss of bone mass. Fifty-five calcium stone forming patients with either absorptive hypercalciuria (AH) or fasting hypercalciuria (FH), 29 males and 26 premenopausal females, were submitted to dual photon absorptiometry at lumbar spine. Calcium intake was assessed by a 72 hr dietary record. OP was detected in 20% (11/55) of patients, being more common among men, 9/26 (35%) than in women, 2/29 (7%), p < 0.05. Male FH patients presented lower mean bone mineral density (BMD) than sex, weight and age-matched control (1.058 +/- 0.18 vs 1.209 +/- 0.13 g/cm2, X +/- SD, p < 0.05). OP was more frequent in FH patients, 7/20 (35%) than in AH patients 4/35 (11%), albeit the difference was not statistically significant. There was no correlation between calcium intake and BMD measurement. Six osteopenic male FH patients were further submitted to histomorphometric evaluation with tetracycline double labeling. Bone volume was lower than the controls (13.2 +/- 3.0 vs 27.2 +/- 3.7%, p < 0.05). Osteoid surfaces were reduced, although not significantly (10.1 +/- 8.2% vs 15.9 +/- 6.7%). Eroded surfaces were markedly increased (23.9 +/- 13.4 vs 4.2 +/- 1.4%, p < 0.05). The bone formation rate was very low with a complete lack of tetracycline double labeling in 4 patients. These data suggest low bone volume, tendency to low bone formation, increased bone resorption and a severe mineralization defect, consistent with normal or low bone turnover osteoporosis.

Absorptiometry, Photon↗

PubMed1994

Effects of nutritional supplementation on bone mineral status of children with rheumatic diseases receiving corticosteroid therapy.

OBJECTIVE: Because children with rheumatic disease receiving longterm corticosteroids are at high risk for developing osteoporosis, we attempted to determine whether nutritional supplementation would improve bone status in this group of children. METHODS: In a crossover design study, 10 corticosteroid treated children with rheumatic disease and osteoporosis received calcium and vitamin D supplementation for 6 months to determine their effect on bone density. They were then studied for 6 months without added nutrition supplements. The mean age was 13.1 years with a mean duration of disease of 4.2 years. Six patients had juvenile rheumatoid arthritis, 2 had systemic lupus erythematosus and 2 had mixed connective tissue disease. These children obtained a minimum of 1 g of calcium and 400 IU of vitamin D daily from diet and added supplements. Dual photon absorptiometry, laboratory and dietary data were obtained at baseline, 6 months, and one year. RESULTS: Spinal bone density significantly improved with supplementation. Osteocalcin values remained low throughout the study. CONCLUSION: Our results suggest some children with rheumatic disease receiving corticosteroids would benefit from calcium and vitamin D supplementation.

1-Carboxyglutamic Acid↗

PubMed1994

[Bone density measurements and their indications].

Today the following two methods of measuring the bone mineral density (BMD) are widely used: dual-photon absorptiometry with X-rays (DEXA) and quantitative computed tomography (qCT). DEXA measures the BMD of the vertebral column, the femur and the whole skeleton, qCT the vertebral column and the radius and tibia. The qCT method permits a distinction to be made between trabecular and cortical bone, which offers an advantage in terms of the choice of treatment because cortical and trabecular bone do not change in parallel. For example, fluorides are contraindicated when cortical bone is diminished. There are important differences among the methods of densitometry concerning reproducibility. The highly sensitive method of peripheral qCT (Densiscan) has an overall reproducibility of 0.3% (mixed population), allowing a change in BMD of less than 1% to be detected. This enables us to adapt quickly the treatment according to the stage and progression of the disease. In the perimenopausal patient, bone mineral densitometry is indicated to detect high-risk patients; in the postmenopause patient, densitometry should be performed in order to "tailor" the treatment of osteoporosis. Patients with a "slow loser" osteoporosis are preferably treated with bone-simulating substances (e.g., fluorides, ossein-hydroxyapatite compound), patients with a "fast loser" osteoporosis (trabecular bone loss, measured at the distal radius, of more than 3.5% per year) with anti-resorption agents such as estrogens, bisphosphonates, calcitonin and anabolic steroids. This tailored treatment reduces not only the number of non-responders, but improves patient compliance because it allows the choice, duration or change of the treatment to be substantiated by means of hard data.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

PubMed1993

Changes in mandibular mineral content 3 years after residual ridge augmentation with porous hydroxyapatite: a clinical report.

Changes in the bone mineral content (BMC) of edentulous mandibles after augmentation with porous hydroxyapatite (HA), in blocks (B) in one side and in granules (G) in the opposite side, were measured in vivo by dual-photon absorptiometry. The BMC changes in each side at the 1-, 2-, and 3-year follow-up were expressed in percent of the 1-week postoperative BMC value. In unexposed augmentations new bone formation seems to occur during the first year in the HA-B sides, followed by the biologic age-related BMC loss; while the HA-G sides show pronounced resorption of hydroxyapatite and bone during the entire period. Although porous HA-B and HA-G are unsuitable for residual ridge augmentation, porous HA-B may be used for implantation in areas without risk for exposure of HA resulting from loading of covering soft tissues.

Absorptiometry, Photon↗

PubMed1993

Osteoporosis and bone metabolic parameters in dependence upon calcium intake through milk and milk products.

The bone mineral content of young adults as well as of osteoporotic patients and age-matched controls without bone disease was measured by single-photon absorptiometry. A retrospective nutrition survey was additionally made to study the relationship between bone mineral content and calcium intake in different periods of life. The bone mineral content and bone mineral density of young adults is directly related to the calcium intake through milk and dairy products. The osteoporotics had a significantly lower bone mineral content than the controls. Calcium intake through milk and milk products in childhood and adolescence had been significantly lower in the patients than in the controls, whereas in the later periods of life (20-30 years prior to the study and at the time of the study) there were no significant differences between the calcium intakes of the two groups. It was also found that an adequate intake of calcium protected against increased bone resorption, as evidenced in particular by the reduced levels of serum osteocalcin, a parameter of bone turnover. In conclusion it can be stated that the data support the hypothesis that adequate calcium intake through milk and milk products in childhood and adolescence is a decisive marker for obtaining a maximum bone mass (peak adult bone mass) and for the prevention of osteoporosis. Furthermore, it can be stated that increased calcium intake in the later years may not reduce the accelerated risk of osteoporosis resulting from inadequate calcium intake during childhood and adolescence.

Absorptiometry, Photon↗

PubMed1993

Variation of cortical hypertrophy depending on the medullary filling material. An experimental study of canine tibial diaphysis.

In order to evaluate the mineralization of bone after polymethyl methacrylate cementation, measurements of the periosteal apposition were made histologically and measurements of the bone-mineral content were made by dual-photon absorptiometry of the tibial diaphysis in 15 adult mongrel dogs in paired studies. Six dogs were investigated 4 weeks after intramedullary reaming of both sides and obturation of the medullary cavity with bone-wax on one side. Nine dogs were reamed on both sides. The medullary cavities were filled with polymethyl methacrylate bone-cement and bone-wax, respectively. The authors found (1) an increased bone-mineral content and an increased periosteal apposition after filling with bone-wax in comparison with the reamed side and (2) a decreased bone-mineral content and a decreased periosteal apposition on the cemented side in comparison with bone-wax. These findings are interpreted as consequential upon repair processes with a high remodeling and mineralization rate after reaming or filling with bone-wax, whereas remodeling in inhibited after filling with acrylic bone-cement.

Absorptiometry, Photon↗

PubMed1993

Equine cricoid cartilage densitometry.

The density of the cricoid cartilage from 29 equine larynges collected from an abattoir was determined by dual photon absorptiometry (DPA). Densities of the right and left cricoid cartilages were highly correlated. No correlation was found between age of the horse and the density of the cricoid cartilage.

Absorptiometry, Photon↗

PubMed1993

Low bone mineral density at axial and appendicular sites in amenorrheic athletes.

Amenorrheic athletes have low axial bone-mineral density (BMD, g.cm-2). We compared 12 amenorrheic and 9 eumenorrheic women athletes to determine whether athletes with amenorrhea have lower BMD in other skeletal regions, including weight-bearing lower limbs. BMD was measured by dual energy x-ray and single photon absorptiometry. Both groups had similar age, body mass, and exercise quantity. Women with amenorrhea missed 86.3 +/- 58.3 menstrual periods since menarche. BMD was lower in the amenorrheic vs eumenorrheic subjects for the lumbar spine (0.928 +/- 0.056 vs 1.050 +/- 0.110, P < 0.005), whole body (1.032 +/- 0.05 vs 1.09 +/- 0.06, P < 0.05), most regions of the whole body (P < 0.05-0.001), all areas of the proximal femur (P < 0.005), and at the femoral mid-shaft (1.333 +/- 0.109 vs 1.491 +/- 0.088, P < 0.005). No significant differences were detected at the mid-radius and tibial shaft. The best predictors of BMD were years of regular menstruation for lumbar spine; and years of amenorrhea for hip, femoral mid-shaft, and whole body. We conclude that low BMD in athletes with amenorrhea is not limited to the axial skeleton but is also present in other regions including appendicular weight-bearing bones.

Absorptiometry, Photon↗

PubMed1993

[Is it possible to identify women with rapid vertebral bone loss during menopause? Result of a longitudinal study of 92 women at the onset of menopause].

Low bone mass is the main risk factors for osteoporosis. The role of the rate of bone loss following cessation of menses is more difficult to evaluate. We prospectively studied vertebral bone loss in 92 women six months to three years after cessation of menses in order to determine the clinical and biological characteristics of the subgroup of subjects with accelerated bone loss. Clinical characteristics, hormone assay results, and values of the main biochemical markers of bone turnover were recorded at the initial evaluation and correlations between these parameters and the rate of bone loss were investigated. Serial measurements of vertebral bone density were performed using dual photon absorptiometry. Mean duration of the observation period was 31 +/- 13 months. Mean rate of bone loss was -1.66% per year (range 1.6% to 7.7%). In women with accelerated vertebral bone loss i.e., a greater than 2.5% decrease in bone density per year (25th centile), there were trends towards lower values for body mass index and weight (non-significant) and a significantly higher urinary calcium/urinary creatinine ratio (p < 0.05) as compared with the rest of the study group. Rate of bone loss was weakly correlated (p < 0.05) with body mass index (r = 0.22) and with the urinary calcium/urinary creatinine ratio (r = 0.23) but demonstrated no correlations with osteocalcin levels or serum alkaline phosphatase activity. In conclusion, none of the clinical features or laboratory parameters studied proved capable of reliably predicting the rate of vertebral bone loss in individual women shortly after cessation of menses.

Absorptiometry, Photon↗

PubMed1993

Osteoporosis, metabolic aberrations, and increased risk for vertebral fractures after partial gastrectomy.

A case-control study compared 129 men with earlier partial gastrectomy (operation during the period 1952-1961) with 216 men from a community-based population study. All were born 1910-1915 and the mean age was 72 years. Men with a previous partial gastrectomy had vertebral fractures in 19% compared with 4% (P < 0.01) in the control population. Bone mineral density (BMD) in the right calcaneus measured with dual energy photon absorptiometry was 20% lower in men with a Billroth II operation (P < 0.001) and 8% lower with a Billroth I operation (ns). In comparison with the controls, the men subjected to partial gastrectomy had higher serum concentrations of osteocalcin and alkaline phosphatase activity, a lower serum concentration of 25-hydroxyvitamin D (25OHD) and a lower body mass index (BMI). There were no difference in serum concentrations of free calcium, intact parathyroid hormone (PTH), or free thyroxine. The smoking prevalence was significantly higher in men with partial gastrectomy than in controls. Smokers had significantly lower serum concentrations of intact PTH and 25OHD than nonsmokers and also lower BMD and BMI. The relationships between intact PTH on one hand, and ionized calcium (inverse relationship) and osteocalcin (direct relationship) on the other were preserved in smokers, however. Gastroscopy was performed in 78 men with multiple biopsies in the gastric remnant and also in the small intestine. All but two subjects had chronic gastritis. Examination of sternal bone marrow smears showed that 40% of the Billroth-operated men lacked bone marrow reticular iron.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

PubMed1993

Noninvasive monitoring techniques for quantitative description of callus mineral content and mechanical properties.

The noninvasive evaluation of fracture healing may allow more precise timing of fixation device removal, quantitative recommendations for weight bearing, and the prediction of abnormal fracture healing patterns. Techniques used for the evaluation of intact bone and of healing fractures include resonance frequency and impedance methods, the measurement of sound speed using ultrasound, computed tomography of ultrasonic energy, roentgenographic photodensitometry, quantitative computed tomography (QCT), single-photon absorptiometry (SPA), and dual-energy x-ray absorptiometry (DEXA). A study comparing QCT, SPA, and DEXA showed that all three techniques had strong correlations with the torsional properties of healing canine tibial osteotomies. Quantitative computed tomography and SPA had stronger correlations with local gap tissue properties than DEXA. The relatively poor performance of DEXA may have been related to the relatively large resolution (2 mm) of the device used in the study. Current DEXA devices have resolutions as low as 0.5 mm, perhaps enhancing its capabilities. Computed tomography of ultrasonic energy, QCT, SPA, and DEXA each appear to have great potential for future use in the evaluation of fracture healing.

Absorptiometry, Photon↗