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1.
While metal or plastic interbody spinal fusion devices are manufactured to appropriate mechanical standards, mechanical properties of commercially prepared structural allograft bone remain relatively unassessed. Robust models predicting compressive load to failure of structural allograft bone based on easily measured variables would be useful. Three hundred twenty seven femoral rings from 34 cadaver femora were tested to failure in axial compression. Predictive variables included age, gender, bone mineral density (BMD), position along femoral shaft, maximum/minimum wall thickness, outer/inner diameter, and area. We used support vector regression and 10‐fold cross‐validation to develop robust nonlinear predictive models for load to failure. Model performance was measured by the root‐mean‐squared‐deviation (RMSD) and correlation coefficients (r). A polynomial model using all variables had RMSD = 7.92, r = 0.84, indicating excellent performance. A model using all variables except BMD was essentially unchanged (RMSD = 8.12, r = 0.83). Eliminating both age and BMD produced a model with RMSD = 8.41, r = 0.82, again essentially unchanged. Compressive strength of structural allograft bone can be estimated using easily measured geometric parameters, without including BMD or age. As DEXA is costly and cumbersome, and setting upper age‐limits for potential donors reduces the supply, our results may prove helpful to increase the quality and availability of structural allograft. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1271–1276, 2014.  相似文献   

2.
Bone mineral density and prevalent vertebral fractures in men and women   总被引:2,自引:0,他引:2  
To test the hypothesis that the association between bone mineral density (BMD) and estimated volumetric BMD and prevalent vertebral fractures differs in men and women, we studied 317 Caucasian men and 2,067 Caucasian women (average age 73 years). A total of 43 (14%) men and 386 (19%) women had a vertebral fracture identified on lateral spine radiographs using vertebral morphometry. Hip and spine areal BMD was about 1/3 standard deviation lower among men and women with a vertebral fracture. A 0.10 g/cm2 decrease in areal BMD was associated with 30–40% increased odds of having a fracture in men and 60–70% increased likelihood in women. Low bone mineral apparent density (BMAD) was also associated with 40–50% increased odds of a vertebral fracture in both genders. The probability of a man having a fracture was observed at higher absolute areal BMD values than observed for women (P=values for interaction of BMD × gender: trochanter, P=0.05; femoral neck, P=0.10; total hip, P=0.09). In contrast, the probability of fracture was similar in men and women across the range of estimated volumetric BMD (BMAD). In conclusion, low BMD and low BMAD are associated with increased odds of vertebral fracture in both men and women. Measures of bone mass that partially correct for gender differences in bone size may yield universal estimates of fracture risk. Prospective studies are needed to confirm this observation.  相似文献   

3.
The aim of this study was to explore the effect of long-term cross-sex hormonal treatment on cortical and trabecular bone mineral density and main biochemical parameters of bone metabolism in transsexuals. Twenty-four male-to-female (M-F) transsexuals and 15 female-to-male (F-M) transsexuals treated with either an antiandrogen in combination with an estrogen or parenteral testosterone were included in this cross-sectional study. BMD was measured by DXA at distal tibial diaphysis (TDIA) and epiphysis (TEPI), lumbar spine (LS), total hip (HIP) and subregions, and whole body (WB) and Z-scores determined for both the genetic and the phenotypic gender. Biochemical parameters of bone turnover, insulin-like growth factor-1 (IGF-1) and sex hormone levels were measured in all patients. M-F transsexuals were significantly older, taller and heavier than F-M transsexuals. They were treated by cross-sex hormones during a median of 12.5 years before inclusion. As compared with female age-matched controls, they showed a significantly higher median Z-score at TDIA and WB (1.7±1.0 and 1.8±1.1, P<0.01) only. Based on the WHO definition, five (who did not comply with cross-sex hormone therapy) had osteoporosis. F-M transsexuals were treated by cross-sex hormones during a median of 7.6 years. They had significantly higher median Z-scores at TEPI, TDIA and WB compared with female age-matched controls (+0.9±0.2 SD, +1.0±0.4 SD and +1.4±0.3 SD, respectively, P<0.0001 for all) and reached normal male levels except at TEPI. They had significantly higher testosterone and IGF-1 levels (p<0.001) than M-F transsexuals. We conclude that in M-F transsexuals, BMD is preserved over a median of 12.5 years under antiandrogen and estrogen combination therapy, while in F-M transsexuals BMD is preserved or, at sites rich in cortical bone, is increased to normal male levels under a median of 7.6 years of androgen treatment in this cross sectional study. IGF-1 could play a role in the mediation of the effect of androgens on bone in F-M transsexuals.  相似文献   

4.
目的观察短期使用大剂量糖皮质激素(glucocorticoid,GCs)对骨转换标志物、骨密度(bone mineral density,BMD)和骨小梁评分(trabecular bone scores,TBS)的影响。方法选取33例(女性19例,男性14例,平均年龄49岁)需要静脉注射(Iv)甲基强的松治疗的活动性Graves’眼病患者。所有患者均给予中位累积剂量4.5 g(范围1.5~5.25 g)iv甲基强的松。分别于基线、1周和第1、3、6、12个月测定骨代谢生化指标(25羟维生素D、PTH、P1NP、CTX和BALP)。在基线、6个月和12个月时通过X射线吸收测量法(DXA)获得受试者BMD和TBS。结果PTH、BALP、P1NP无明显变化。1个月时CTX显著下降(比基线下降49.31%,P=0.02),在3个月测量时恢复到基线。P1NP有改变(不显著),但持续下降。BMD或TBS无明显变化。结论短期大剂量GCs治疗可快速、短暂地抑制骨吸收,对BMD或骨微结构(TBS)无影响。  相似文献   

5.
目的研究葛根素对绝经后骨质疏松大鼠骨代谢、骨密度及骨生物力学的影响,探讨中医药防治绝经后骨质疏松症(postmenopausal osteoporosis,PMOP)的作用机制。方法48只大鼠随机分为正常组、去卵巢组、骨化三醇组和葛根素组,12只/组,构建绝经后骨质疏松大鼠动物模型并给予不同药物干预8周,正常组和去卵巢组:5 mL/kg 0.9%NaCl,ih,qd;葛根素组:葛根素35 mg/kg,ih,qd;骨化三醇组:骨化三醇0.25μg,po,qd,连续给药6周。检测各组大鼠血清骨代谢指标、骨组织(BMD、BMC)和骨生物力学指标,SP法检测各组骨组织ER表达,HE观察骨组织形态学变化。结果去卵巢组大鼠血清骨代谢指标、腰椎和股骨BMD和BMC、股骨骨生物力学指标较正常组显著降低(P<0.05),骨化三醇组和葛根素组上述指标较去卵巢组均显著增高(P<0.05),葛根素组上述指标较骨化三醇组均增高(P<0.05)。去卵巢组大鼠骨组织ER蛋白表达较正常组显著降低(P<0.05),骨化三醇组和葛根素组ER蛋白表达较去卵巢组均显著增高(P<0.05),葛根素组ER蛋白表达较骨化三醇组均增高(P<0.05)。去卵巢组骨皮质明显变薄,骨小梁稀疏纤细或断裂,排列紊乱,髓腔明显扩大,造血细胞明显减少。葛根素组骨皮质结构较完整,骨小梁数目增多,致密均匀粗壮,连接成网状,髓腔变小,造血细胞增多。结论葛根素通过提高绝经后骨质疏松大鼠雌激素水平,调节骨代谢,提高骨量和骨密度,改善骨生物力学性能和骨形态学结构,起到抗PMOP的疗效和骨保护作用。  相似文献   

6.
Seventy-four postmenopausal women with nonpathological hip fracture were recruited to a study in which they were compared for lifetime factors, some biochemical measurements of bone metabolism, and bone mineral density (BMD), with 40 age-adjusted controls without fracture. The fracture patients were less independent; their walking ability was weaker; their vision was poorer; they had more general diseases (strokes, diabetes, malignant diseases, heart and vascular diseases); more of them had had deliveries; and they were using significantly more loop diuretics, and antidepressant, neuroleptic, and diabetes drugs than the controls. Thirty-seven patients and 19 controls were excluded from the statistical comparison of BMD and the biochemical measurements of bone metabolism because they had had treatments with calcium, vitamin D, bisphosphonates, estrogens, calcitonin, or corticosteroids, and one fracture patient was excluded for primary hyperparathyroidism. The BMD of the upper femur was significantly lower in the fracture group compared with the control group. Serum total calcium (S-Ca) and serum vitamin D (S-25-(OH)-D) were significantly lower and the levels of calcitonin (S-CT) significantly higher in the fracture group than in the control group, but none of the bone formation markers showed significant differences between the study groups. A comparison of patients with cervical and trochanteric fractures showed BMD to be significantly lower in the upper femur in the trochanteric fracture group. There were no significant differences in the biochemical measurements (with the exception that S-CT was higher in the cervical fracture group), nor in the lifetime factors between the fracture types. In conclusion, some lifetime factors and low S-Ca, low S-25-(OH)-D, high S-CT, and low BMD of the upper femur seem to be related to the risk of hip fracture, and low BMD and low S-CT seem to be related to the trochanteric fracture type in postmenopausal women.  相似文献   

7.
In the last decade, more accurate quantitative methods to assess bone mass in vivo have become available. We have applied these techniques to assess periodic changes of bone loss in rheumatoid arthritis (RA) patients. In this longitudinal study, 132 female RA patients were divided into two groups. The first group of 90 patients were postmenopausal, with a mean age of 60.2 years (PM group), whereas the second group of 42 patients were premenopausal, with a mean age of 42.7 years (M group). The clinical courses of these patients were followed for an average of 3 years. Bone mineral density (BMD) in the lumbar spine (L2–L4), and the femoral neck were measured by dual-energy X-ray absorptiometry (DXA), and second metacarpal bone mineral density was measured by using densitometric techniques periodically. Reduction of BMD in the lumbar spine was significant in both groups (P<0.01–0.05), but there was no statistical difference between the two groups. The BMD of the femoral neck had a tendency to decrease but this was not significant. The predictors for periodic bone loss in the PM group were aging and nutritional factors, whereas for the M group they were indices of rheumatoid arthritis disease activity.  相似文献   

8.
9.
We investigated the incidence and degree of stress shielding and clinical and radiographic results in 2 groups of patients. Fifty patients (60 hips) in each group were enrolled for a randomized study. One group received a short, metaphyseal-fitting femoral component and another group received a conventional metaphyseal- and diaphyseal-filling femoral component. The mean follow-up was 3.35 years in both groups. Bone mineral density was significantly increased in femoral zone 1 but slightly decreased in zone 7 in the short, metaphyseal-fitting stem group. In the conventional metaphyseal- and diaphyseal-fitting stem group, bone mineral density was markedly decreased in both zones 1 and 7. Clinical and radiographic results were similar between the 2 groups. No hip in either group required revision of the component.  相似文献   

10.
We evaluated the efficacy of parathyroidectomy (PTX) on bone mineral density (BMD) and hormonal and biochemical markers of bone metabolism in elderly primary hyperparathyroidism (PHPT) patients, and followed these patients for 5 years after PTX. Eleven PHPT patients were enrolled and were followed for 5 years by measuring lumbar spine BMD (LSBMD), femoral BMD (FBMD), radial BMD (RBMD), parathyroid hormone (PTH), 1,25-dihydroxyvitamin D [1,25(OH)2D], serum calcium (SCa), inorganic phosphate (iP), bone-specific alkaline phosphatase (BAP), intact osteocalcin (IOC), urinary excretion of type I collagen cross-linked N-telopeptide (NTx), and urinary deoxypyridinoline (DPD). PTX produced significant increases in LSBMD of 12%, 19%, and 29% as compared with pretreatment levels after 1, 3, and 5 years, respectively (P < 0.01, compared to baseline), whereas there was no significant increase in FBMD and a slight decrease in RBMD. SCa and iP levels remained normal over the five years. PTX also resulted in significant decreases in PTH, 1,25(OH)2D, BAP, IOC, NTx, and DPD that continued for at least 3 years after PTX. In conclusion, PTX seemed effective to normalize various markers of bone metabolism in elderly PHPT patients and is recommended to patients with low LSBMD to prevent future fractures. On the other hand, the use of PTX for low FBMD or RBMD patients requires further discussion.  相似文献   

11.
Stress shielding after total hip arthroplasty (THA) remains an unsolved issue. Various patterns of mechanical stress appear according to the type of femoral stem used. To compare differences in mechanical stress conditions between Zweymuller type and fit-and-fill type stems, finite element analysis (FEA) was performed. Differences in bone mineral density (BMD) changes in the femur were also compared. Maximum stress was confirmed in Gruen zone 4, whereas zone 1 had the minimum amount of stress with both types of implant. The Zweymuller stem group had less mechanical stress and lower BMD in zone 7 than the fit-and-fill stem group. In conclusion, differences in mechanical stress may be related to changes in BMD after THA.  相似文献   

12.
13.
Women with established osteoporosis are at high risk to sustain additional vertebral fractures. Treatment may affect the predictive power of bone densitometry and biochemical techniques. There are few prospective studies comparing fracture prediction by dual-energy X-ray absorptiometry (DXA) and other techniques in treated women with established osteoporosis. The objective of this study was to prospectively assess the predictive power of various DXA and quantitative ultrasound (QUS) techniques for identification of women at high risk to develop new fractures over 1-2 yr. Moreover, we wanted to investigate whether previous or ongoing therapy precluded the use of common clinical laboratory blood tests and bone turnover markers for prediction of fracture risk. We measured prevalent fracture status; bone mineral density (BMD) of the whole body, spine, and hip by DXA; QUS of the calcaneus and the patella; hormones and various markers of bone resorption and formation; and took standard blood tests in 124 women (age 64.9 yr +/- 7.9) with manifest and variously treated postmenopausal osteoporosis. Subsequently, new spine fractures were assessed after 1 yr and, in a subset of 87 women, after 2 yr. Prevalent fractures turned out to be the strongest predictor of subsequent vertebral fractures with an age-adjusted odds ratio (OR) of 3.9 per prevalent fracture over 2 yr. Furthermore, our results underline the predictive power of spinal BMD (sOR = 2.1; standardized OR per 1 standard deviation population variance decrease), whole body BMD (sOR: 2.4), and QUS stiffness index of the calcaneus (sOR: 2.8) for vertebral fracture prediction. QUS of the patella did not predict vertebral fractures. Blood sedimentation rate was predictive in the first year (sOR: 1.9). The predictive power of bone turnover markers, however, appeared to be too low to be detectable in a group of this sample size and it may have been reduced because most women were already receiving treatment. In conclusion, radiographic measures, but not the tested laboratory bone turnover markers, enabled us to identify women (from a population of osteoporotic women who have been treated for some time with a variety of medications) who are at highest risk for developing new vertebral fractures within 1-2 yr.  相似文献   

14.
This study investigated the role of quantitative ultrasound (QUS) for evaluation of fracture risk in comparison with bone mineral density (BMD) measurement. Our subjects were postmenopausal Japanese women (n = 260; age, 67 ± 6.1 years) who were examined for bone densitometry, QUS, and spinal X-ray examination at our department between 1992 and 1996. The subjects were categorized into three groups by the number of atraumatic fractured vertebrae: NF, no vertebral fractures; F1, one vertebral fracture; F2, two or more vertebral fractures. We compared the measured parameters to determine their association with the number of fractured vertebrae. Differences among groups were compared and analyzed by Student's t-test. Odds ratios were also calculated after age adjustment, as well as age and lumbar or calcaneal parameters. Between NF and F1, lumbar BMD and BMD of the Ward's triangle showed more significant differences than other values, while between F1 and F2, whole-body BMD and QUS parameters showed more significant differences. Lumbar BMD also showed the highest age-adjusted odds ratio in differentiating F1 from NF. Although QUS parameters showed no power to differentiate between NF and F1, these values showed higher odds ratios than other measurements for discriminating between F1 and F2. Adjustment for bone density did not totally abolish the association between QUS parameters and vertebral fracture. Additionally, the combination of lumbar BMD and QUS ("stiffness") clearly showed a high power to discriminate NF from F1 + F2. In conclusion, we showed that QUS measurement is effective in evaluating fracture risk in advanced osteoporosis, while lumbar dual X-ray absorptiometry is effective in evaluating risk in early osteoporosis. Received: Sept. 7, 1998 / Accepted: Nov. 27, 1998  相似文献   

15.
目的探讨绝经后妇女血维生素B12、叶酸水平与骨密度的相关性。方法应用双能X线骨密度仪测定受试者腰椎及股骨骨密度,按1994年WHO标准将其分为3组,即骨质疏松组、骨量减少组及骨量正常组;采取空腹静脉血进行维生素B12、叶酸的集中检测;并分别进行维生素B12、叶酸与不同部位骨密度的相关性分析。结果①骨质疏松组的血维生素B12的水平(512.55±209.85)pg/ml,低于骨量减少组(551.29±237.71)pg/ml和骨量正常组(565.71±189.03)pg/ml。②骨质疏松组的血叶酸的水平(11.27±6.04)pg/ml,低于骨量减少组(13.18±6.14)pg/ml和骨量正常组(11.9±3.73)pg/ml。③绝经后妇女血维生素B12的水平与全髋BMD呈正相关(r=0.25,P<0.01),与股骨颈BMD呈正相关(r=0.212,P<0.05),与股骨干BMD呈正相关(r=0.257,P<0.01),与股骨大转子BMD呈正相关(r=0.239,P<0.05);血维生素B12的水平与L1~L4BMD无相关性(r=0.141,P>0.05)。④绝经后妇女血叶酸的水平与全髋BMD、股骨颈BMD、股骨干BMD、股骨大转子BMD和L1~L4BMD均无相关(r分别为0.005,0.021,0.017,-0.021和0.078,P>0.05)。结论绝经后妇女血维生素B12的水平的缺乏可能是骨质疏松发生的一个重要风险因素,叶酸的缺乏并非骨质疏松发生的风险因素。  相似文献   

16.
The aims of this study were to determine whether subjects with aseptic loosening after total hip arthroplasty (THA) have regional differences in periprosthetic bone mineral density (BMD) and systemic biochemical markers of bone turnover compared to subjects with successful implants.Proximal femoral and pelvic BMD were measured by dual energy X-ray absorptiometry and bone turnover markers were assayed in 49 subjects 12.6+/-4.3 (mean+/-SD) years after cemented THA. Femoral BMD was lower in Gruen zones 2, 5, 6, and 7 in subjects with a loose femoral implant (n=17) compared to those (n=32) with fixed femoral implants (P<0.05 all comparisons). This BMD difference was greatest (-31%, P=0.02) in the proximal and medial region of the femur. Subjects with femoral loosening had higher levels of the bone resorption marker N-telopeptides of type-I collagen (P=0.02) than those with a fixed femoral implant. No differences in pelvic BMD or bone turnover markers were found between subjects with loose (n=18) versus fixed (n=31) pelvic implants.This study suggests that failure of femoral components after cemented THA is associated with region-specific decreases in BMD and an increase in urinary excretion of N-telopeptide cross-links of type-I collagen. These surrogate outcome markers may be of value in monitoring response to antiresorptive therapies used to treat periprosthetic osteolysis, although the diagnosis of aseptic loosening remains clinical and radiological.  相似文献   

17.
Bone mineral density (BMD) is a significant determinant of risk for osteoporosis. Genetic factors are known to account for a major proportion of variation of BMD in Caucasians. However, the degree of genetic determination of BMD in Chinese populations has seldom been investigated. The aim of our study was to investigate the magnitude of the genetic determination of BMD at the spine and hip, and their genetic covariation, in a population of Shanghai city in P. R. China. The subjects consisted of 44 full-sib pairs of females aged 19–43 years, 186 mother-daughter pairs, and 270 nuclear families. For BMD at the spine and hip, the values for narrow-sense heritability h 2 (±SE) were 0.72 ± 0.14 and 0.87 ± 0.14, respectively, when estimated by full-sib pairs, and 0.44 ± 0.07 and 0.77 ± 0.07, respectively, when estimated by mother-daughter pairs. There was a significant genetic correlation r g (±SE) of BMD between the spine and hip, of 0.97 ± 0.01 and 0.76 ± 0.04, respectively, when estimated by full-sib pairs and mother-daughter pairs. The common household impact on BMD in our study was negligible according to the statistical estimate. We conclude that genetic factors play a major role in the determination of the variation and covariation of BMD at the spine and hip in our Chinese sample.  相似文献   

18.
双能X线吸收法腰椎侧位骨密度测定的临床研究   总被引:1,自引:0,他引:1       下载免费PDF全文
目的评价双能X线吸收法测定腰椎骨密度时侧位的临床价值。方法178例女性患者(按年龄分组)接受腰椎后前位和侧位骨密度测定,以BMD表示骨密度值,以T值为标准判断骨量正常、骨量减少和骨质疏松,评价腰椎后前位与侧位T值对骨量减少程度的判断和骨质疏松诊断的差别。结果①各年龄组患者腰椎后前位BMD值均高于侧位值;②各年龄组患者腰椎后前位及侧位T值对骨量减少程度的判断有显著性差别;③当大于50岁时,腰椎后前位及侧位T值对骨质疏松诊断有显著性差别。结论腰椎侧位对女性患者骨量减少程度的判断和骨质疏松的诊断(>50岁)都有一定临床价值。  相似文献   

19.
 Studies on polymorphisms of candidate genes and their association with bone mineral density (BMD) have been reported in many populations, but few have been reported in Chinese populations. We investigated polymorphisms of the following five commonly used markers of four prominent BMD candidate genes with the purpose of identifying useful genetic markers for osteoporosis genetic research in Chinese: the Sp1 and RsaI polymorphisms of the collagen type 1 alpha l (Col1a1) gene, the −174G/C promoter polymorphism of the interleukin 6 (IL-6) gene, the Asn363Ser polymorphism of the glucocorticoid receptor (GR) gene, and the T → C polymorphism in intron 5 of the transforming growth factor β1 (TGF-β1) gene. We evaluated these polymorphisms using PCR-RFLP in samples of at least 124 random individuals. We compared the polymorphisms of these five markers with other populations using the χ2 test and Fisher's exact two-tailed test. For the RsaI polymorphism, only three heterozygotes but no variant homozygote were identified. For the −174G/C polymorphic site, only one GC heterozygote and no CC homozygote were found. Alleles s, Ser, and A 1 at the Sp1, Asn363Ser, and T → C marker sites that have been found to be polymorphic in other populations were not found in Chinese. Significant differences of allele and genotype frequency distributions were observed at these polymorphisms (P < 0.001) after comparing with other populations. Our results suggest that variant alleles of the five markers are absent or too rare to be useful genetic makers in Chinese, despite the fact that they have been commonly used as polymorphic markers in osteoporosis genetic research in other populations. Received: April 22, 2002 / Accepted: July 2, 2002 Acknowledgments. The study was partially supported by the Hunan Province Special Professor Start-up Fund (25000612), Chinese National Science Foundation (CNSF) Outstanding Young Scientist Award (30025025), CNSF Grant (30170504), a grant from Huo Ying-Dong Education Foundation, and a Seed Fund from the Ministry of Education of P.R. China (25000106). Some investigators (R.R.R., V.D., H.W.D.) were partially supported by grants from the Health Future Foundation of USA, grants of National Health Institute (K01 AR02170-01, R01 GM60402-01A1), grants from the State of Nebraska Cancer and Smoking Related Disease Research Program, and U.S. Department of Energy grant (DE-FG03-00ER63000/A00). We thank all the study subjects for volunteering to participate in the study. Offprint requests to: H.-W. Deng  相似文献   

20.
Calcium-sensing receptor (CaSR) is an attractive candidate gene for osteoporosis susceptibility. The CaSR “A986S” genotype has been shown to have an effect on serum calcium. Recently, an association has been reported between the CaSR gene A986S polymorphism and bone mineral density in healthy white girls. In this study, we examined whether CaSR gene A986S polymorphism is associated with decreased bone mass in 230 Hungarian postmenopausal women. From this cohort, 108 osteoporotic patients were compared with 122 healthy control women. Bone mineral density (BMD) was measured at the lumbar spine (L2–4) and femoral neck using dual-energy X-ray absorptiometry. Allele-specific polymerase chain reaction was used to amplify A986S polymorphisms of the CaSR gene. We found no difference in the distribution of different alleles or genotypes between groups (p = 0.762). No significant effect of CaSR genotype on BMD was observed either in the whole population or in the subgroups. Our data do not support the idea that CaSR gene A986S polymorphism has an impact on bone mass.  相似文献   

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