Influence of the menopause and aging on spinal density in French women

Dual photon absorptiometry (DPA) was used to measure the bone mineral density (BMD) of the lumbar spine in 510 normal women from the south of France. Long-term precision was 2.2%. BMD was stable in young adults and again in women over 70 years of age. Perimenopausal women at an average age of 51 years already evidenced a slight bone diminution (5%) compared to young adults and women within 2 years of the menopause already had a 10% diminution. The average rate of apparent bone loss in this cross-sectional study was 1% per year from age 45 to 65 years, but about 75% of this decrease occurred in the first decade after the menopause. Spinal BMD in our normal French population appears to be 5–10% lower than US values.     

Study on Bone Density at Various Skeletal Sites for the Diagnosis of Primary Osteoporosis

The objective of this study was to evaluate the diagnostic value of bone density changes in lumbar vertebrae and femoral necks in patients with primary osteoporosis (OP) at various ages. Dual-energy X-ray absorptiometry (DXA) scans were performed on patients who had their primary visits between March 2008 and February 2009. The bone mineral density (BMD) of the lumbar vertebrae 1-4 (L1-L4) in anteroposterior projection and the proximal femoral neck in lateral projection were measured. If the BMD values (T score) of any site is -2.5 or less (T ≤?-2.5), the patients were diagnosed as primary OP, and the T scores were statistically analyzed. The 81 patients who had lumbar vertebrae with a T ≤?-2.5 led to a positive rate of 80.1?% in the diagnosis of primary OP; the 47 patients who had femoral neck with a T ≤?-2.5 gave a positive rate of 47.0?%. The patients with type I or type II primary OP were divided into two age groups of ≤70 and ≥71?years old. The comparison of lumbar spine T score values did not show significant statistical difference (P?>?0.05) between the age groups, while the result of the femoral necks revealed significant difference between the two groups (P?相似文献   

Radiological evaluation of bone status in the jaw and in the vertebral column in a group of women

Vertebral bone mineral content was determined in a group of 56 women, ages 30–62. These measurements were compared with the status of supporting bone in the jaws (alveolar, molar and bicuspid) and with gingival health. There was a significant decline in vertebral bone mineral content from the pre- to post-menopausal group. Molar and bicuspid measurements were highly correlated. There was some association between lumbar bone mineral content and molar bone status for postmenopausal women. For postmenopausal women, the cases of greatest percent bone loss in alveolar crest were associated with lower lumbar bone mineral content. Gingival health did not confound the bone status measurements. The 56 subjects did not exhibit the degree of reduction in bone density that is observed in the general population. Further investigation using these radiographic techniques may reveal a link between substantial bone loss in the jaw and moderate to severe bone loss in the lumbar vertebrae.     

Noninvasive estimation of bone mass in ancient vertebrae

Histomorphometry is useful in the assessment of trabecular bone mass (TBM), and thus, in the estimation of the prevalence and intensity of osteopenia in ancient population groups. However, it is a destructive method. It is therefore necessary to explore the accuracy of nondestructive approaches, such as radiography, bone mineral density (BMD) assessed by double-energy X-ray absorptiometry (DEXA), bone density (BD), or optical density (OD) in the diagnosis of osteopenia. We selected 51 vertebrae out of a total sample composed of 333 T12, L1, and L2 vertebrae belonging to adult pre-Hispanic inhabitants from El Hierro. These vertebrae underwent histomorphometrical analysis, a fine-grained film radiography with assessment of trabecular pattern following standard methods, OD, DEXA-assessed BMD, and BD. The presence of biconcave vertebrae and wedge-shaped vertebrae was also assessed by measuring anterior height (a), posterior height (p), and height at the middle point of the vertebral body (m), and further calculating the indices 2m/(a + p) ("spine score") and a/p. Significant correlations were observed between TBM and BMD (r=0.43), TBM and BD (r=0.49), TBM and OD (r=0.52), BMD and OD (r=0.51), and BMD and BD (r=0.36), but not between TBM and the indices 2m/(a + p) and a/p. In the stepwise multiple correlation analysis between TBM and BMD, BD, and OD, OD entered into first place and BD into second place, whereas BMD became displaced; the multiple correlation coefficient was 0.63, with a standard error of 3.78. A BMD greater than 0.60 g/cm2, or a bone density greater than 0.60 g/cm3, excluded osteopenia (TBM <15%) with a specificity greater than 90%, whereas a BMD value less than 0.35 g/cm2, a BD less than 0.35 g/cm3, or optical density >1.6 excluded a normal bone mass (TBM >20%) with a specificity greater than 90%. Based on radiographic criteria on the total sample, we also conclude that the overall prevalence of vertebral fractures in the adult pre-Hispanic population of El Hierro of any age is 7.5%.     

Association of CYP19 Gene Polymorphism with Vertebral Fractures in Japanese Postmenopausal Women

This study investigates aromatase gene polymorphism, which might influence bone strength in terms of mineral density and quality. We explored the relationship between CYP19 polymorphisms and vertebral fractures in postmenopausal Japanese women. In addition, we compared estrogen and testosterone levels in Japanese postmenopausal women with and without fractures. Osteoporotic postmenopausal women showed higher incidences of vertebral fractures than osteopenic women or women with normal lumbar bone mineral density (L2-4 BMD). Estrogen concentrations in postmenopausal women were associated with BMD; however, no association was found between sex hormone levels and the presence of fractures. The C allele rs2470152 was significantly associated with increased risk of vertebral fractures (P = 0.04), whereas none of the CYP19 polymorphisms showed differences in sex steroid levels between subjects with and without fractures. Allelic variants of aromatase genes appear to interact to influence the risk of vertebral fractures in postmenopausal Japanese women.     

Spatial distribution of trabeculae in iliac bone from 145 osteoporotic females

145 women showing clinical and radiological signs of involutional osteoporosis of the spine were biopsed at the ilium for histomorphometric analysis of bone mass including trabecular bone volume and parameters reflecting the spatial distribution of bony elements (mean trabecular plate thickness, density and separation). Results were compared with an age-matched population of 22 healthy females. Postmenopausal osteoporotics (i.e. younger than 75 years) were characterized by a significant reduction in trabecular bone volume, plate density and thickness, while senile osteoporotics (i.e. older than 75 years) did not exhibit any difference with controls. 51% of the osteoporotic patients had a trabecular bone volume higher than the spontaneous vertebral crush threshold defined by Meunier. Osteoporotic patients with trabecular bone volume under the vertebral crush threshold had a significant decrease in all trabecular parameters. On the opposite, patients with trabecular bone volume above the vertebral crush threshold had only a significant decrease in the number of trabeculae. A negative correlation was found between age and plate density in both osteoporotic patients and controls. A linear correlation was found between trabecular bone volume and plate density, but thickness and density of trabecular plates were not correlated. This study confirms that involutional osteoporosis is not only a decreased bone mass disorder. A modified spatial distribution of trabeculae or a mechanically less resistant bone matrix could be additional factors.     

Factors influencing the results of osteodensitometry in searching for systemic osteoporosis

Osteodensitometry (ODM) performed in 485 persons aged 15 to 83 years, referred for ODM due to their having various causes, has demonstrated a significant reduction in bone density in both males and females above 50 years of age. The density of each vertebra individually in patients without cancer and inflammation of the spine is different, even in youth. The difference between the density of the bodies of individual vertebra increases with age. The vertebral density difference is particularly great in osteoplastic metastases. All the processes accompanied by osteogenesis or calcification both within and around the bone increase ODM values excessively. ODM values are decreased by not only osteoporosis, but also by any other bone destruction (tumorous, inflammatory, non-inflammatory), the increased area of a portion under study due to neoplasia of an immature bone, and by intestinal gas at the level of lumbar vertebrae. The older the patient is, the more factors distorting the results of ODM are. The role of each factor is reflected in the present communication. Not only the densitometric, but also X-ray patterns of the area under study should be taken into account to give an objective and final assessment of a specific situation.     

Negative impact of Crohn's disease on bone mineral mass

Prolonged chronic inflammation and corticosteroid therapy increase the risk of osteoporosis in patients with Crohn's disease. It has been estimated that 30% of these patients, who take steroids for prolonged periods, will suffer a vertebral fracture. Patients with Crohn's disease are difficult to wean from corticosteroids and therefore are at risk of developing bone complications. The purpose of this cross-sectional study was to examine the relationship between cumulative steroid dose, duration of the disease and the development of osteopenia in patients with Crohn's disease. We studied 28 patients (17 men, 11 women) with Crohn's disease: eight had one or more bowel resections and all the women were premenopausal. Serum calcium, phosphate, total alkaline phosphatase, immunoreactive parathyroid hormone (iPTH), 25(OH)Vitamin D(3) and 1,25 (OH)(2) Vitamin D(3) were measured by autoanalyser methods or radioimmunoassay. Bone mineral density (BMD) was studied using dual energy X-ray bone absorptiometry of the lumbar spine (L2-L4) and the femoral neck. Of these 28 patients, 27 received an average of 17.3 +/- 21.7 g (range 1 to 80) g of prednisone over a period of 4 to 216 months. Fourteen out of the 28 patients had mildly diminished bone density (z-score >-2.5 SD and < -1 SD) of the spine and 15/28 of the hip. We found a greater decrease in bone density (z-score < -2.5 SD) in 2 out of 28 patients at the spine and in 5 out of 28 at the femoral neck. Those in whom the duration of the disease was less than two years (12 patients) had significantly higher vertebral z-scores (-0.096 +/-0.91) than those who had the disease for over two years (-1.31 +/- 2.37), (p<0.05). We found no significant correlation between lumbar spine and femoral neck z-scores and cumulative steroid therapy. Six out of 28 patients (four women and two men), of mean age 47.2+/-11.7, had one vertebral fracture. The mean cumulative dose of steroids (prednisone or budesonide) in patients with vertebral fractures was higher but not significantly different from that in patients without fractures -20.1+/-18.2 versus 14.1+/-11.2 g of prednisone, respectively (p>0.05). No correlation was found between various serum hormones and other biochemical parameters of bone turnover or bone density. We conclude that a large proportion of patients with Crohn's disease have reduced bone mineral density (58% at the spine and 75% at the femoral neck). The pathogenesis of bone loss is probably multifactorial. Although steroid therapy might be an important contributory factor, we were unable to find a significant correlation between it and bone loss. On the contrary, we observed that the duration of the disease makes a significant contribution to bone loss.     

Relation of common allelic variation at vitamin D receptor locus to bone mineral density and postmenopausal bone loss: cross sectional and longitudinal population study.

OBJECTIVE: To determine whether common allelic variation at the vitamin D receptor locus is related to bone mineral density and postmenopausal bone loss. DESIGN: Cross sectional and longitudinal population study. SETTING: Outpatient clinic in research centre. SUBJECTS: 599 healthy women aged 27 to 72 and 125 women with low bone mass aged 55-77 had bone mineral density measured once in the cross sectional study. 136 women aged 45-54 were followed up for 18 years in the longitudinal study. MAIN OUTCOME MEASURES: Bone mineral density measured at the lumbar spine, hip, and forearm and rate of bone loss at different times over 18 years in relation to vitamin D receptor genotype as defined by the endonucleases ApaI, EsmI, and TaqI. RESULTS: Vitamin D receptor genotype was not related to bone mineral density at any site. The maximum difference between homozygotes was 1.3% (P = 0.33, n = 723). Women with low bone mineral density had almost the same genotype frequencies as the women with normal bone mineral densities. Vitamin D receptor genotype was not related to early postmenopausal bone loss from age 51 to 53 (mean (SD) total loss at the lower forearm -3.6% (3.6%)), late postmenopausal bone loss from age 63 to 69 (at the hip-6.2% (8.7%)), or to long term postmenopausal loss from age 51 to 69 (at the lower forearm-24.5% (11.4%)). CONCLUSION: Common allelic variation at the vitamin D receptor locus as defined by the endonucleases ApaI, EsmI, and TaqI is related neither to bone mineral density nor to the rate of bone loss in healthy postmenopausal Danish women.     

Brief communication: Transportation and trauma: Dog‐sledding and vertebral compression in Alaskan Eskimos

Vertebral compression, as evidenced by compression of the centrum, was observed within two Native Alaskan skeletal samples. Information was collected from 1,071 and 656 vertebrae from Golovin Bay and Nunivak Island, Alaska, respectively. In addition, patterns of compression related vertebral change in each collection were characterized by sex and location within the vertebral column. The overall frequencies of vertebral compression were 3.6% (n = 721) at Golovin Bay and 1.7% (n = 403) at Nunivak Island for all observable thoracic and lumbar vertebrae (T1–L5). There was no statistically significant difference in the occurrence of compression among adults between these two collections. When examining the thoracic and lumbar vertebral segments by sex, females at Golovin Bay (4.5%; n = 442) exhibited a significantly higher frequency of vertebral compression than females at Nunivak (1.0%; n = 203). However, this difference in occurrence of compression could be accounted for by the age distributions of the two samples. No difference was noted between the males of the two collections. Compression frequencies in both samples are discussed in relation to the modes of transportation historically utilized by each community. Am J Phys Anthropol, 2010. © 2010 Wiley‐Liss, Inc.     

Bone quality assessment in individuals of different age, gender and body constitution

The concept of bone quality describes the sets of the characteristics of the osseous tissue that influence bone strength. The aim was to explore the influence of anthropometric parameters and age on the parameters of the bone architecture and bone mineral properties in the lumbar vertebral bone of men and women. Vertebral bone samples underwent bone histomorphometry, bone densitometry and atomic absorption spectrometry. Men have greater values of the bone volume and thicker bone trabeculae in relation to women, which indicates that vertebral bone architecture is better preserved in men than in women. Age is the best predictor of changes that affect bone architecture and bone mineral properties. Bone mineral density value and calcium concentration are both negatively predicted by age, but positively predicted by body mass index. Such result supports the opinion that low body mass index is associated with conditions of bone deficit such are osteopenia and osteoporosis.     

Bone mineral density, osteopenia, and osteoporosis in the rhesus macaques of Cayo Santiago

This cross-sectional study investigates metabolic bone disease and the relationship between age and bone mineral density (BMD) in males and females of a large, well-documented skeletal population of free-ranging rhesus monkeys (Macaca mulatta), from the Caribbean Primate Research Center Museum collection from Cayo Santiago, Puerto Rico. The sample consists of 254 individuals aged 1.0-20+ years. The data consist of measurements of bone mineral content and bone mineral density, obtained from dual-energy X-ray absorptiometry (DEXA), of the last lumbar vertebra from each monkey. The pattern of BMD differs between male and female rhesus macaques. Females exhibit an initial increase in BMD with age, with peak bone density occurring around age 9.5 years, and remaining constant until 17.2 years, after which there is a steady decline in BMD. Males acquire bone mass at a faster rate, and attain a higher peak BMD at an earlier age than do females, at around 7 years of age, and BMD remains relatively constant between ages 7-18.5 years. After age 7 there is no apparent effect of age on BMD in the males of this sample; males older than 18.5 years were excluded due to the presence of vertebral osteophytosis, which interferes with DEXA. The combined frequency of osteopenia and osteoporosis in this population is 12.4%. BMD values of monkeys with vertebral wedge fractures are generally higher than those of virtually all of the nonfractured osteopenic/osteoporotic individuals, thus supporting the view that BMD as measured by DEXA is a useful but imperfect predictor of fracture risk, and that low BMD may not always precede fractures in vertebral bones. Other factors such as bone quality (i.e., trabecular connectivity) should also be considered. The skeletal integrity of a vertebra may be compromised by the loss of key trabeculae, resulting in structural failure, but the spine may still show a BMD value within normal limits, or within the range of osteopenia.     

Effect of misoprostol on bone mineral density in women with postmenopausal osteoporosis

OBJECTIVE: To evaluate the effect of misoprostol on bone mineral density in postmenopausal women. MATERIALS AND METHODS: The study was performed in a randomized controlled prospective manner in 90 women with menopause at Süleymaniye Maternity and Women's Diseases Teaching and Research Hospital between January and December 2003. Cases were divided into three groups each consisting of 30 women who were in menopause for at least 1 year and had t-scores less than -1 by dual energy X-ray densitometry (DEXA). Group I was treated with misoprostol and calcium, Group II received tibolone and calcium and Group III was given calcium only and considered as control group. In all patients, bone mineral density in L1-L4 vertebrae, femur neck and Ward triangle were measured by DEXA and t and z scores were calculated. RESULTS: All groups were similar demographically. Bone mineral density in L1-L4 vertebrae, femur neck and Ward triangle in the group treated with misoprostol, increased by 5, 8.1 and 3.6%, respectively. In the tibolone group, bone mineral density in L1-L4 vertebrae, femur neck and Ward triangle increased by 8.3, 5.3 and 7.8%, respectively. There was not a significant difference in t and z-scores and bone mineral density measurements between misoprostol and tibolon groups. CONCLUSION: Misoprostol may be an alternative treatment for patients with osteopenia and osteoporosis who are not suitable for hormone replacement therapy.     

Exercise,smoking, and calcium intake during adolescence and early adulthood as determinants of peak bone mass. Cardiovascular Risk in Young Finns Study Group.

OBJECTIVE--To evaluate the contribution to peak bone mass of exercise, smoking, and calcium intake in adolescents and young adults. DESIGN--Prospective cohort study with end point measurement (bone mineral density) after 11 years'' follow up for lifestyle. SETTING--Five university hospital clinics. SUBJECTS--264 (153 females, 111 males) subjects aged 9 to 18 years at the beginning of the follow up and 20 to 29 years at the time of measurement of bone mineral density. MAIN OUTCOME MEASURE--Bone mineral density of lumbar spine and femoral neck by dual energy x ray absorptiometry; measures of physical activity and smoking and estimates of calcium intake repeated three times during follow up. RESULTS--In the groups with the lowest and highest levels of exercise the femoral bone mineral densities (adjusted for age and weight) were 0.918 and 0.988 g/cm2 for women (P = 0.015, analysis of covariance) and 0.943 and 1.042 g/cm2 for men (P = 0.005), respectively; at the lumbar spine the respective values were 1.045 and 1.131 (P = 0.005) for men. In men the femoral bone mineral densities (adjusted for age, weight, and exercise) were 1.022 and 0.923 g/cm2 for the groups with the lowest and highest values of smoking index (P = 0.054, analysis of covariance). In women the adjusted femoral bone mineral density increased by 4.7% together with increasing calcium intake (P = 0.089, analysis of covariance). In multiple regression analysis on bone mineral density of the femoral neck, weight, exercise, age, and smoking were independent predictors for men; with weight, exercise, and age for women. These predictors together explained 38% of the variance in bone mineral density in women and 46% in men. At the lumbar spine, weight, smoking, and exercise were predictors for men; and only weight for women. CONCLUSIONS--Regular exercise and not smoking is important in achieving maximal peak bone mass in adolescents and young adults.     

Effect of pamidronate treatment on vertebral deformity in children with primary osteoporosis. A pilot study using radiographic morphometry

OBJECTIVE: Bisphosphonates are effectively used in treatment for primary osteoporosis in children. In the present study, we quantitatively evaluated the effect of pamidronate treatment on lumbar vertebrae in children with primary osteoporosis using radiographic morphometry. METHODS: Paired lateral radiographs of the lumbar spine were obtained before and after pamidronate treatment in 5 children with primary osteoporosis. To characterize vertebral deformities, specific morphometrical ratios were calculated for vertebral bodies L1-L4. RESULTS: Significant reshape of lumbar vertebrae was observed: the concavity index (middle-anterior ratio) decreased from 55 to 36% (p = 0.006), and the anterior-posterior ratio (used as a surrogate of wedge deformity) decreased from 25 to 11% (p = 0.001). CONCLUSIONS: Pamidronate treatment significantly influences the restoration of vertebral fractures in children with primary osteoporosis. The present study demonstrates that radiographic morphometry is a suitable tool for quantitative assessment of the vertebral deformities in childhood.     

Organization of the <Emphasis Type="Italic">MASP2</Emphasis> locus and its expression profile in mouse and rat

The identification of vertebral fracture in osteoporosis is based mainly on the identification of abnormal variation in vertebral shape, but this can be misleading in the presence of a non-fracture deformity or normal variant of vertebral shape. Qualitative identification of vertebral fracture (Qual) is influenced by the subjectivity of the approach, and although more objective, the semiquantitative method (SQ) can be difficult to apply. In addition, there has been little independent evaluation of SQ in relation to other approaches. We aimed to evaluate a new algorithm-based approach for the qualitative identification of vertebral fracture (ABQ) and to compare it with SQ and Qual. Two radiologists reported spinal radiographs for 372 postmenopausal women using Qual (reader 1), and SQ and ABQ (reader 2). Non-fracture deformities and normal variants were also reported using Qual and ABQ. The prevalence of vertebral fracture by subjects was higher for SQ (24%) than for Qual (11%) and ABQ (7%). Agreement was poor between SQ and the other methods, and moderate between Qual and ABQ. Twenty-two women with vertebral fracture were agreed by all three methods, similar to the total identified by ABQ (25 women). Seventeen women diagnosed with fracture by Qual, had non-fracture deformity or normal variant (but no fracture) according to ABQ. Of the women with SQ fractures, 53% and 70% were identified negative for fracture but positive for non-fracture deformity or normal variant by ABQ and Qual. The main sources of discrepancy between SQ and the other methods were Scheuermanns disease, normal variation, and degenerative change accompanied by short anterior vertebral height. For all methods, bone mineral density (BMD) and BMD Z-scores were lower in women with vertebral fractures than in those with no fractures. Bone mineral density and BMD Z-scores were also lower at the lumbar spine and total body in women with vertebral fractures according to Qual and ABQ than they were for SQ, and were lower in women with SQ fractures agreed by Qual and ABQ, compared with those diagnosed negative for fracture by Qual and ABQ (p<0.01). We conclude that poor agreement between methods arises mainly from difficulties in differentiating true fracture from non-fracture deformity. Our new approach attempts to address this problem but requires further testing in a larger study population.     

Bone density parathyroid hormone and 25-hydroxyvitamin D concentrations in middle aged women.

OBJECTIVE--To examine the relation between bone density and indices of calcium metabolism including parathyroid hormone and 25-hydroxyvitamin D concentrations in middle aged women. DESIGN--A cross sectional study. SETTING AND SUBJECTS--138 women volunteers aged 45-65 with no known osteoporosis and unselected for disease status recruited for a dietary assessment study from the community using general practice registers. Volunteer rate was 20%. MAIN OUTCOME MEASURE--Bone mineral density measured with dual energy x ray absorptiometry. RESULTS--Bone density at the lumbar spine and neck and trochanteric regions of the femur was inversely related to serum intact parathyroid hormone concentrations and positively related to serum 25-hydroxyvitamin D concentrations. These associations were independent of possible confounding factors, including age, body mass index, cigarette smoking habit, menopausal status, and use of diuretics and postmenopausal hormone replacement therapy. These associations were apparent throughout the whole distribution of bone density and 25-hydroxyvitamin D and parathyroid hormone concentrations within the normal range, suggesting a physiological relation. CONCLUSIONS--The findings are consistent with the hypothesis that parathyroid hormone and 25-hydroxyvitamin D concentrations influence bone density in middle aged women. Findings from this study together with other work suggest that the role of vitamin D in osteoporosis should not be neglected. The associations with parathyroid hormone also indicate plausible biological mechanisms. The roughly 5-10% difference in bone density between top and bottom tertiles of serum 25-hydroxyvitamin D concentrations, though not large in magnitude, may have considerable public health implications in terms of prevention of osteoporosis and its sequelae, fractures.     

Bone measurement by enhanced contrast image analysis: ovariectomized and intact Macaca fascicularis as a model for human postmenopausal osteoporosis

This paper presents an image enhancement and analysis system (DARWIN) based on an inexpensive microcomputer and applies the system to two bone morphometry problems relevant to postmenopausal osteoporosis. Using ovariectomized and intact female Macaca fascicularis as a model, we examined the radiodensity of the sixth lumbar vertebra and the cross-section area of the right femur. Significantly lower bone density was observed in the vertebral segments of the ovariectomized animals. No significant differences were observed in comparisons of the femoral cross sections. The reduction in radiographic density of the ovariectomized animals' vertebrae is similar to that observed in postmenopausal women, supporting the use of female cynomolgus macaques as models of bone loss in postmenopausal osteoporosis.     

Correlation of thoracic and lumbar vertebral failure loads with in situ vs. ex situ dual energy X-ray absorptiometry

In this study we explore the hypothesis that estimates of failure loads in the thoracic spine by lumbar dual energy X-ray absorptiometry (DXA) are compromised of skeletal heterogeneity throughout the spine and artifacts of spinal DXA. We studied the correlation between mechanical failure loads of thoracic and lumbar vertebrae, and that of in situ vs. ex situ lumbar DXA with thoracic and lumbar fracture loads, respectively. One hundred and nineteen subjects (76 female, age 82+/-9yr; 43 male, age 77+/-11yr) were examined under in situ conditions (anterior-posterior direction), the scans being repeated ex situ (lateral projection) in 68 cases. The failure loads of thoracic vertebrae (T) 6 and 10, and lumbar vertebra (L) 3 were determined in axial compression, using a functional 3-segment unit. The correlation between thoracic failure loads (T6 vs. T10) was significantly (p<0.01) higher (r=0.85) than those between thoracic and lumbar vertebrae (r=0.68 and 0.61, respectively). Lateral ex situ DXA displayed a significantly higher correlation (p<0.05) with lumbar vertebral fracture loads than in situ anterior-posterior DXA (r=0.85 vs. 0.71), but the correlation of thoracic failure loads with lateral ex situ lumbar DXA was similar to that obtained in situ in anterior-posterior direction (r=0.69 vs. 0.69 for T10, and r=0.61 vs. 0.65 for T6). The correlation between fracture loads of different spinal segments, and between DXA and failure loads was not significantly different between men and women. The results demonstrate a substantial heterogeneity of mechanical competence throughout the spine in elderly individuals. Because of the high incidence of fractures in the thoracic spine, these findings suggest that, clinically, lateral DXA involves no relevant advantage over anterior-posterior measurements of the lumbar spine.     

Vertebral morphometry in diagnosis of spinal fractures

Vertebral morphometry was performed on lateral thoracic and lumbar radiographs of 153 women with a preliminary diagnosis of spinal osteoporosis. Measurements included anterior and posterior vertebral height, width, area, wedge angle, percent reduction of anterior to posterior height (PRH) and percent difference in anterior height between adjoining vertebrae (PDAH). A vertebral fracture was identified if any of the measurements which control for interindividual variation in vertebral size (wedge angle, PRH, PDAH) were below the normal range.Among individuals with mild osteoporosis (0–2 fractures) PDAH identified 86% of the fractures and 95% of the individuals with fractures. Other measurements identified less than 71% of the fractures and less than 80% of the individuals with fractures. Although the results reflect a relative rather than a true sensilivity it appears that PDAH is the better diagnostic measurement for fractures in the earlier stages of spinal osteoporosis.