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PubMed2003

Effect of bone chip orientation on quantitative estimates of changes in bone mass using digital subtraction radiography.

OBJECTIVES: To assess the effect of the orientation of arbitrarily shaped bone chips on the correlation between radiographic estimates of bone loss and true mineral loss using digital subtraction radiography. METHODS: Twenty arbitrarily shaped bone chips (dry weight 1-10 mg) were placed individually on the superior lingual aspect of the interdental alveolar bone of a dry dentate hemi-mandible. After acquiring the first baseline image, each chip was rotated 90 degrees and a second radiograph was captured. Follow-up images were created without the bone chips and after rotating the mandible 0, 1, 2, 4, and 6 degrees around a vertical axis. Aluminum step tablet intensities were used to normalize image intensities for each image pair. Follow-up images were registered and geometrically standardized using projective standardization. Bone chips were dry ashed and analyzed for calcium content using atomic absorption. RESULTS: No significant difference was found between the radiographic estimates of bone loss from the different bone chip orientations (Wilcoxon: P > 0.05). The correlation between the two series of estimates for all rotations was 0.93 (Spearman: P < 0.05). Linear regression analysis indicated that both correlates did not differ appreciably ( and ). CONCLUSION: It is concluded that the spatial orientation of arbitrarily shaped bone chips does not have a significant impact on quantitative estimates of changes in bone mass in digital subtraction radiography. These results were obtained in the presence of irreversible projection errors of up to six degrees and after application of projective standardization for image reconstruction and image registration.

Alveolar Process↗
PubMed2003

Loss of bone mineral of the hip and proximal tibia following rupture of the Achilles tendon.

In a prospective uncontrolled study 12 patients suffering from a rupture of the Achilles tendon treated operatively with surgical repair and post-operative immobilization in a short plaster cast for 6 weeks had bilateral measurements of bone mineral content (BMC) of the proximal tibia and bone mineral density (BMD) of the femoral neck and greater trochanter. The measurements were performed by dual energy X-ray absorptiometry (DEXA) and scans were performed post-operatively within 7 days after the operation and with follow up after 6 weeks, 3, 6, and 12 months. In the operated legs, BMC of the proximal tibia showed a progressive decrease reaching a total bone loss of 6.4% (95%-CL: -10.6%; -2.3%) 1 year after the injury. Bone mineral density at the hip of the operated legs also decreased significantly and 1 year after the injury BMD was 2.5% (95%-CL: -5.5%; 0.5%) and 6.8% (95%-CL: -9.8%; -3.7%) below the initial value in, respectively, the femoral neck and greater trochanter. Patients with a previous Achilles tendon rupture must be considered to be some years ahead in their natural osteoporotic process of the bones of the affected legs, and an increased risk of osteoporotic fractures must be considered not to be only theoretical.

Absorptiometry, Photon↗
PubMed2001

Bone density reduction in patients with Crohn disease and associations with demographic and disease variables: cross-sectional data from a population-based study.

BACKGROUND: The extent of bone density reduction in patients with Crohn disease is still being debated. The aim of this study was to examine bone mineral density (BMD) and factors associated with reduced BMD in a representative population of patients with Crohn disease aged between 20 and 70 years. METHODS: BMD (using dual energy X-ray absorptiometry) was measured in spine and hip in 55 patients with Crohn disease recruited from the entire Crohn population (n = 96) in a defined area of southern Norway. Demographic and clinical data were also collected. The patients were compared with 52 age- and gender-matched healthy controls. Potential demographic and disease-related factors associated with BMD reduction were statistically tested with bi- and multivariate analyses. RESULTS: The BMD reduction in patients with Crohn disease was 7.1% (P = 0.02) in spine L1-4, 6.1% (P = 0.08) in femoral neck and 8.4% (P = 0.02) in total hip as compared with the controls. In total hip and femoral neck, age, body weight and gender were independently associated with reduced BMD, but in the spine only body weight. Among the disease-related variables, only ever use of prednisolone was independently associated with reduction in BMD but this only in the femoral neck. CONCLUSIONS: The spine and hip BMD reduction of 6%-8% is similar to that found in a comparable population-based study performed in another area in Norway. Among the disease-related variables tested for, only the use of prednisolone was independently associated with BMD reduction. However, the BMD reduction measured in this study indicates that disease-related mechanisms are involved.

Absorptiometry, Photon↗
PubMed1999

Determinants of bone loss in patients with Kock ileal urinary reservoir.

The purpose of the present study was to determine the change in bone mineral density (BMD) measured with dual energy X-ray absorptiometry (DXA) in patients with Kock reservoirs for urinary diversion who were examined with the same technique 3 years earlier, and relate the changes to kidney function and variables reflecting bone metabolism. A total of 28 patients with Kock ileal reservoirs to the skin (23) or urethra (5) were reinvestigated 3 years after the first measurement. BMD was measured in the lumbar spine, femur and whole body with DXA. Bone specific alkaline phosphatase, osteocalcin, parathyroid hormone (PTH), calcitonin and chloride were also determined in serum. GFR was determined from the plasma clearance of 51Cr-EDTA. The mean values for BMD expressed in percentage of corresponding mean values for age-matched controls (BMD%) were almost identical after 3 years. Only osteocalcin levels correlated with the BMD% values. However, significant positive correlations were found between GFR and the observed individual changes in BMD% over the 3 years in spite of the fact that most GFR values were fairly normal. Enhanced bone loss was associated with high concentrations of osteocalcin and bone specific alkaline phosphatase. Comparisons with blood gas analyses and determination of 1,25 dihydroxyvitamin D performed in the previous study indicate to us that the relation between reduced GFR and low mineral content might, in part, be related to a low-grade metabolic acidosis and reduced availability of the biologically active vitamin D hormone. The conclusion to be drawn is that urinary diversion with a Kock reservoir does not regularly cause bone demineralization. However, patients with even moderately reduced GFR appear to be at risk for developing osteoporosis in the long-time run.

Adult↗
PubMedDate not supplied

Case report: the management of bone demineralization associated with long-term treatment of multiple paraphilias with long-acting LHRH agonists.

A patient with multiple paraphilias had been successfully treated for 10 years with a long-acting LHRH agonist with complete suppression of deviant sexual activity. However, during treatment, he demonstrated bone demineralization, as documented by serial bone densitometry studies. A treatment regimen was instituted, which resulted in the cessation or partial reversal of bone loss.

Adult↗
PubMed2003

Mandible and maxilla bone mineral density and threshold analysis studies by pQCT in two edentulous women receiving pamidronate.

The mandible and maxilla of two edentulous women, treated during 25 weeks with oral pamidronate, were monitored by peripheral quantitative tomography (pQCT). Whole bone volumetric mineral density failed to show meaningful variations after treatment. However, an analysis of separated cortical and medullar areas disclosed focal bone loss at the right mandible cortex of patient #1 and at the left maxilla cortex of patient #2. These and other bone sub-regions were further studied by clustering the internal sites with a different degree of bone mineral density, resorting to the mineral threshold analysis provided by the system. Where bone loss was detected, it corresponded to increased loss of the most osteopenic sites, while medium and high-density portions tended to remain unchanged within the region. There were no significant variations in all other regions, or alternatively, minor losses at osteopenic sites were compensated by an increase at high-density portions. Hence, the pQCT system allowed monitoring volumetric bone mineral density at particular sites of interest, discriminating variations at portions with a dissimilar degree of bone volume. Further studies should confirm whether pamidronate exerts a protective effect on sub-regions with previous medium and high degrees of bone mineralization, as suggested by our present findings.

Bone Demineralization, Pathologic↗
PubMed1995

Possible limited bone loss with suppressive thyroxine therapy is unlikely to have clinical relevance.

To determine the effect of suppressive doses of thyroxine (T4) on bone mass, we studied 50 women on suppressive doses of T4 for 3-27 years (mean of 11 years). Twenty-five had nontoxic goiter and 25 had well-differentiated thyroid carcinoma. Fifty controls were matched for age, menopausal status, and body mass index. Bone mineral density (BMD) was measured in the lumbar spine (LS), femoral neck (FN), trunk (TK), and extremities (EXT) by dual-energy X-ray absorptiometry (DXA). In addition, the trunk area was measured by neutron activation analysis and recorded as a calcium bone index (CaBI). Twenty-one patients were restudied with DXA measurements at a mean of 1.5 +/- 0.5 (1 SD) years. The total population of 50 patients showed no difference in bone mass from controls. In patients with nontoxic goiter, there was no evidence of any loss in bone mass. Cancer patients showed insignificant reductions of 2-5% in BMD of LS, FN, and TK and a significant 5% reduction in BMD of EXT, compared to controls, and a 12% reduction in CaBI compared to goiter patients. Cancer patients had a slightly higher (p < 0.001) mean daily dose of T4 than goiter patients (0.23 vs 0.15 mg/day) but had a similar degree of TSH suppression. BMD and CaBI values did not correlate with free T4 index) with the daily T4 dose, accumulative dose, or with duration of T4 therapy. There were no significant changes in bone mass in either goiter or cancer patients restudied after a mean of 1.5 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1995

Pathophysiology of immobilization osteoporosis.

The reduction of gravity-related forces on the skeleton creates a type of osteoporosis that is unique because its severity is dependent on the mechanical stress bearing function of the skeleton as well as the length of time that the forces are absent or reduced. Bones that bear weight under normal conditions are more affected than bones that normally do not bear weight. The cytokine environment and the cells in the affected bones are altered in time so that stem cells produce fewer new cells and the differentiated cells tend to be less active. These alterations in the local environment of the affected parts appear to resemble those of age- and disease-associated systemic forms of osteoporosis. The osteoporosis produced as a result of the loss of normal activity however, appears to be at least partially reversible through remobilization, strenuous exercise, and--possibly in the future--cytokine therapy.

Animals↗
PubMed1996

Bone demineralization following urinary intestinal diversion assessed by urinary pyridinium cross-links and dual energy x-ray absorptiometry.

PURPOSE: We investigated the acid-base balance and bone mineral status in patients with 3 types of urinary intestinal diversion. MATERIALS AND METHODS: Of 46 men with urinary intestinal diversions 20 had a Kock pouch, 15 had an Indiana pouch and 11 had an ileal conduit. Acid-base balance was assessed by arterial blood gas analysis. Bone mineral status was measured by urinary pyridinium cross-links and dual energy x-ray absorptiometry. In addition, urinary deoxypyridinoline was measured in 79 patients. RESULTS: Of the 46 patients 7 (15%) with the Kock pouch (1), Indiana pouch (5) and ileal conduit (1) had metabolic acidosis associated with significantly lower bone mineral densities (p < 0.05) and higher urinary pyridinium cross-links (p < 0.005) than did those with normal acid-base status. No difference was found in metabolic acidosis and bone demineralization among the 3 groups. Additionally, in 79 patients urinary deoxypyridinoline reached the highest level immediately postoperatively and then gradually decreased to the stable level within 1 or 2 years. CONCLUSIONS: Metabolic acidosis following urinary intestinal diversion results in bone demineralization. The types of diversion did not cause differences in metabolic acidosis and bone resorption. Bone has a major role in buffering acid overload in the early postoperative period.

Absorptiometry, Photon↗
PubMed1999

Bone mineral density in children and young adults with Crohn's disease.

Reduced bone mineral density (BMD) has been reported in adults with Crohn's disease (CD). Less is known about abnormal BMD in children and young adults with CD. The aims of this study are to determine the prevalence of low BMD and to evaluate the effect of growth and pubertal development on BMD in children and young adults with CD. One hundred-nineteen patients with CD underwent dual-energy X-ray absorptiometry (DXA) to determine BMD. Anthropometry and pubertal development were measured. Bone age was measured only in patients older than 8 years of age and who had not grown in height during the last year. One hundred-nineteen patients (72 male, 47 female) were evaluated. Seventy percent of patients had BMD z-scores < or = -1.0 and 32% had z-scores < or = -2.0. Weight and height z-scores were significantly associated with BMD z-scores. BMD z-scores based on bone age and on chronological age were highly correlated, except when the chronological age BMD z-score was < or = -2.0. BMD z-score was significantly different between males and females for the group (-1.75 +/- 1.06 vs. -1.08 +/- 1.00), respectively. Children and young adults with CD have a high prevalence of low BMD and routine evaluation by DXA is indicated. In patients with a chronological age-based BMD z-score < or = -2.0, a bone age-based BMD should be considered.

Absorptiometry, Photon↗
PubMed2004

Bone density loss after spinal cord injury: elite paraplegic basketball players vs. paraplegic sedentary persons.

OBJECTIVE: To compare the bone mineral density of elite paraplegic basketball players with the values obtained from their paraplegic sedentary counterparts. DESIGN: A total of 17 male paraplegic basketball players and 17 male paraplegic sedentary persons were included in the study. Bone mineral densities of the distal third of radius of the dominant arm, L2-L4 spine, and trochanters, Ward's triangles, and the femoral necks of both hips were measured. RESULTS: The densities of trochanters, Ward's triangles, and the femoral necks were found to be decreased in both groups, with no significant difference between them. The densities of lumbar and radial regions were found to be increased in both groups. Radial density was significantly higher in paraplegic basketball players than in paraplegic sedentary patients, whereas the groups were not significantly different for lumbar density. CONCLUSIONS: Wheelchair basketball in spinal cord-injured patients was associated with greater bone density in distal radius compared with sedentary paraplegics. However, it was not associated with greater density below the injury level.

Absorptiometry, Photon↗
PubMed2003

A randomized controlled trial of calcium with vitamin D, alone or in combination with intravenous pamidronate, for the treatment of low bone mineral density associated with Crohn's disease.

BACKGROUND: Osteoporosis is a common complication of Crohn's disease. AIM: To study the effect on the bone mineral density of a bisphosphonate (pamidronate) given intravenously, in combination with oral calcium and vitamin D supplements, compared with oral calcium and vitamin D supplements alone. METHODS: Seventy-four patients with Crohn's disease and low bone mineral density at the lumbar spine and/or hip were randomized to receive either a daily dose of 500 mg of calcium with 400 IU of vitamin D alone or in combination with four three-monthly infusions of 30 mg of intravenous pamidronate over the course of 12 months. The main outcome measure was the change in bone mineral density at the lumbar spine and hip, measured by dual X-ray absorptiometry, at baseline and 12 months. RESULTS: Both groups gained bone mineral density at the lumbar spine and hip after 12 months. There were significant (P < 0.05) changes in the pamidronate group, with gains of + 2.6%[95% confidence interval (CI), 1.4-3.0] at the spine and + 1.6% (95% CI, 0.6-2.5) at the hip, compared with gains of + 1.6% (95% CI, - 0.1-3.2) and + 0.9% (95% CI, - 0.4-2.1) at the spine and hip, respectively, in the group taking vitamin D and calcium supplements alone. CONCLUSIONS: In patients with Crohn's disease and low bone mineral density, intravenous pamidronate significantly increases the bone mineral density at the lumbar spine and hip.

Administration, Oral↗
PubMed2004

Rapid hip bone loss in active Crohn's disease patients receiving short-term corticosteroid therapy.

BACKGROUND: Uncertainty over whether corticosteroids cause bone loss in patients with Crohn's disease may reflect their short, intermittent use. AIM: We investigated whether a 2-month course of prednisolone is associated with detectable bone loss. METHODS: Fifteen patients with active Crohn's disease and 19 controls with inactive Crohn's disease were recruited. Bone mineral density of the lumbar spine and hip was measured at baseline and 2 and 8 months. RESULTS: At 2 months, significant bone loss was found in patients with active disease (femoral neck -2.7%, P < 0.002; Ward's triangle -3.9%, P < 0.01). Although bone mineral density was still lower at 8 months, these differences were no longer significant (-1.3% and -3.4%, femoral neck and Ward's triangle, respectively). No significant change in hip bone mineral density was observed in controls. Previous corticosteroid use was not significantly associated with baseline bone mineral density, although significant independent associations were observed between weight, site of disease and lumbar spine bone mineral density, and between dietary calcium deficiency and femoral neck and Ward's triangle bone mineral density. CONCLUSION: Significant bone loss at the hip can be detected in patients receiving corticosteroid treatment for 2 months for active Crohn's disease ; however, it remains unclear whether this is because of disease activity or its treatment. This rapid bone loss may represent a risk factor for fracture and justify bone protective therapy.

Adult↗
PubMed2005

Comparison of DXA, QCT and trabecular structure in beta-thalassaemia.

Osteopathy, as a major feature of homozygous beta-thalassaemia, is a multifactorial disorder, not fully understood. We studied the lumbar vertebrae of 48 patients using Dual-Energy X-ray Absorptiometry (DXA) and Quantitative Computed Tomography (QCT), and we focused on structural properties, assessed by High Resolution Computed Tomography (HRCT). Bone Mineral Density (BMD) values were expressed as Z-scores and the results were correlated. The effect of age, sex, and type of thalassaemia and hormonal factors on BMD was assessed. We estimated, with HRCT, the cortex integrity and the number and thickness of trabeculae; the latter were classified to a three-grade scale. Our results showed the overall prevalence of osteoporosis to be 44% with DXA and 6% with QCT. Both techniques revealed an inverse correlation between age and BMD, whereas hormonal factors demonstrated associations with QCT and DXA measurements. The correlation coefficient between DXA's BMD and QCT's trabecular BMD was 0.545 (P < 0.001) whereas the corresponding value for Z-scores was r = 0.491 (P < 0.001). The classification of the patients into normal, osteopenic and osteoporotic categories, using QCT's Z, was in better agreement with the assignment based on trabecular number (K = 0.209, P = 0.053) than the classification using DXA's Z (K = 0.145, P = 0.120). Cortex evaluation by HRCT showed discontinuity in 15 patients. Both methods indicate a progression of osteoporosis with age. Hormonal deficiency is associated with thalassaemic osteoporosis whereas the visual estimation of cortex indicates that Thalassaemia Intermedia (TI) patients could be more affected than Thalassaemia Major (TM). Using the trabecular number as an indicator of osteoporosis, it seems that QCT may evaluate osteopathy better than DXA. Since the former has the ability to measure trabecular and cortical BMD separately, it could give early indication of which changes more rapidly and to what degree.

Absorptiometry, Photon↗
PubMed2003

Periimplant bone healing under experimental hepatic osteodystrophy induced by a choline-deficient diet: a histomorphometric study in rats.

BACKGROUND: Osseointegration and success of an implant involve the interaction of local and systemic factors such as bone metabolic diseases. PURPOSE: The purpose of this study was to evaluate the effect of experimental hepatic osteodystrophy induced by a choline-deficient diet on periimplant bone healing. MATERIALS AND METHODS: Laminar titanium implants were placed in the tibias of five groups of Wistar rats: those with a (1). controlled diet for 15 days; (2). choline-deficient diet for 15 days; (3). controlled diet for 30 days; (4). choline-deficient diet for 30 days; (5). choline-deficient diet for 15 days and a controlled diet for 15 days (refeeding). Body weight and food intake, hematocrit, and hemoglobinemia were evaluated. The animals were killed at 15 or 30 days post implantation. The liver, kidneys, and tibias were resected and fixed in 20% formalin solution. The tibias were radiographed and processed for histomorphometric evaluation of the periimplant bone area. RESULTS: Histologic studies revealed steatosis in the liver but no alterations in the kidneys. Rats fed a choline-deficient diet showed periimplant bone healing with marked qualitative and quantitative alterations. The periimplant bone area was 28% and 75% lower in experimental animals than in controls at 15 and 30 days, respectively. CONCLUSIONS: Liver alterations caused by a choline-deficient diet alter periimplant osteogenesis qualitatively and quantitatively.

Analysis of Variance↗
PubMed1995

Bone mineral disorders in children: evaluation with dual x-ray absorptiometry.

PURPOSE: To evaluate the utility of dual x-ray absorptiometry (DXA) in children with bone mineral disorders. MATERIALS AND METHODS: In phase 1, radial DXA was compared with single-energy photon absorptiometry (SPA) (n = 117). In phase 2, radial and lumbar bone mineral density (BMD) measured with DXA and second metacarpal cortical thickness were compared (254 examinations, 224 children). RESULTS: For radial BMD, DXA and SPA correlated well (r = .956) and SPA-equivalent values could be calculated from DXA measurements (mean residual error = 0.024 g/cm2). After controlling for age, sex, weight, and height, partial correlations were very small for lumbar BMD with radial BMD (r = .186) and lumbar BMD with cortical thickness (r = .158), and slightly better for radial BMD with cortical thickness (r = .544). Z scores also correlated poorly with no meaningful correlation for lumbar BMD with radial BMD (r = .07) CONCLUSION: In children with bone mineral disorders, radial DXA and SPA measurements correlate well. However, lumbar BMD, radial BMD, and cortical thickness correlate poorly and lumbar BMD frequently does not identify abnormality in patients with abnormal radial BMD. Lumbar BMD alone is not adequate for evaluation of bone mineral status in these patients.

Absorptiometry, Photon↗
PubMed2000

Lumbar bone mineral density in patients with major depression: evidence of increased bone loss at follow-up.

OBJECTIVE: This study investigated whether an increase in the loss of bone mineral density occurs with major depression. METHOD: The authors measured lumbar bone density with the use of quantitative computerized tomography in a longitudinal assessment of 18 depressed patients older than 40 years on hospital admission and 21 healthy women and men. The follow-up period lasted at least 24 months. RESULTS: A repeated measures analysis of variance model with depression and gender as factors showed that bone loss was greater for the depressed patients than for the comparison subjects and greater for men than for women. CONCLUSIONS: Major depression may be associated with increased bone loss, especially for men.

Absorptiometry, Photon↗