绝经后骨质疏松症对股骨近端的生物学影响

骨质疏松症是一种以系统骨量、骨强度及骨微结构损害为特征常导致骨折风险增加的疾病,是绝经后妇女常见且严重的情况。骨质疏松症在骨折发生前大多是一种隐性疾病,存在着检测和治疗不足的情况。而骨质疏松性骨折的发生常导致疼痛、畸形、活动障碍,对患者的生活质量造成严重影响。绝经后骨质疏松症是一种好发于中老年女性的全身性骨骼系统疾病。众所周知,雌激素是一种维持正常骨量的重要保护因素。绝经后妇女体内雌激素水平的降低与骨量的迅速流失密切相关。在妇女绝经之后,骨重建增加,内在的不平衡加速了骨质流失,最终导致骨质疏松症的形成。干预绝经后骨质疏松症的最主要的目的是防止骨折。最常发生骨质疏松性骨折的部位是椎体(脊柱)、股骨近端(髋部)及前臂远端(腕部)。其中,髋部骨折是骨质疏松症最严重的后果,往往导致重大残疾和过早死亡。鉴于绝经后骨质疏松症的特殊性及髋部骨折的严重性,系统全面地了解绝经后骨质疏松症对股骨近端的影响显得尤为重要。     

体脂量是绝经后女性股骨近端骨强度的决定因素

正Lower body weight or body mass index(BMI)has been known to be higher risk of developing osteoporosis and low-energy fractures via mechanical loading and other factors in both men and women[1].Recently,there have been new insights into the relationships between body composition and bone health.However,most of the previous studies regarding the relative effect of body composition on bone mass yielded inconsistent     

Effects of denosumab on the geometry of the proximal femur in postmenopausal women in comparison with alendronate.

Denosumab is a fully human monoclonal antibody against receptor activator of nuclear factor-kappaB ligand, an essential mediator of osteoclast activity and survival. In postmenopausal women with low bone mineral density (BMD), subcutaneous denosumab decreases bone resorption and increases BMD. This post hoc analysis reports on subjects treated for up to 24 months with denosumab 60mg 6 monthly (N=39), placebo (N=39), or open-label alendronate 70mg once weekly (N=38) in a phase 2 study. Hip scans were done by dual-energy X-ray absorptiometry at baseline, 12, and 24 months; these were analyzed with hip structural analysis software to evaluate BMD and cross-sectional geometry parameters at the narrowest segment of the femoral neck, the intertrochanter, and the proximal shaft. Geometric parameters and derived strength indices included bone cross-sectional area, section modulus, and buckling ratio. At 12 and 24 months denosumab and alendronate improved these parameters compared with placebo. Denosumab effects were greater than alendronate at the intertrochanteric and shaft sites. The magnitude and direction of the changes in structural geometry parameters observed in this study suggest that denosumab treatment may lead to improved bone mechanical properties. Ongoing phase 3 studies will determine whether denosumab reduces fracture risk.     

绝经后女性股骨近端骨密度与骨质疏松性骨折相关性研究

目的：研究绝经后女性股骨近端骨密度的变化规律与骨质疏松症、骨质疏松性骨折间的关系。方法采用法国Medlink公司Osteocore 3型双能X线骨密度仪,对本地区417例绝经后女性股骨颈、大转子、粗隆间、全髋进行骨密度测定。结果骨折组各年龄段、各部位的BMD均比非骨折组低（ P＜0．05）。随着年龄的增长,股骨近端骨量逐渐丢失,除了45～50组,其余各年龄段骨折组的患病率明显高于非骨折组（ P＜0．05）,骨密度值越低,骨折危险性越大。结论绝经后女性股骨近端骨密度与发生骨质疏松性骨折的风险呈明显负相关性,应该注意预防。     

Effects of raloxifene treatment on the structural geometry of the proximal femur in Japanese women with osteoporosis

The purpose of this study was to clarify the effects of 2-year treatment with raloxifene on the proximal femoral geometry among Japanese patients with osteoporosis by hip structure analysis. One hundred ninety-eight community-dwelling postmenopausal women with osteoporosis were enrolled. The structural variables were areal bone mineral density (BMD), cross-sectional area (CSA), section modulus (index of resistance to bending forces), and buckling ratio (index of cortical instability). BMD, CSA, and section modulus at the narrow neck significantly increased by 1.27, 2.67, and 3.90% at 2 years, respectively. BMD, CSA, and section modulus at the intertrochanter significantly increased by 2.55, 4.49, and 6.60% at study termination, respectively. The buckling ratio at the intertrochanter decreased by 2.36% at 1 year, but differences at 2 years became non-significant. Parameters at the shaft were qualitatively similar to those of the narrow neck and intertrochanter. The percent change of the section modulus was significantly higher than that of BMD at 2 years in all three regions. The percent changes of the section modulus is strongly correlated with the percent changes of BMD and CSA, and negative correlated with the percent changes of buckling ratio in all regions. In conclusion, Japanese osteoporotic women on raloxifene therapy have significant improvements of both BMD and geometry in the proximal femur.     

绝经后女性类风湿性关节炎患者腰椎和股骨近端骨密度测量

为了观察绝经后女性类风湿性关节炎（ＲＡ）患者骨矿物质密度水平的变化，采用双能Ｘ线骨密度仪（ＤＥＸＡ）测量２３例绝经后女性ＲＡ患者和年龄、性别匹配的２３例正常健康者的腰椎２～４（Ｌ２～Ｌ４）和右侧股骨近端（股骨颈、大转子和Ｗａｒｄ＇ｓ三角区）的骨密度（ＢＭＤ）。结果表明，绝经后女性ＲＡ患者Ｌ２～Ｌ４、右侧股骨近端的ＢＭＤ测量值（ｇ／ｃｍ２）明显低于年龄和性别匹配的正常健康者（Ｐ＜０．０５）。绝经后女性ＲＡ患者Ｌ２～Ｌ４骨密度的Ｚ－ｓｃｏｒｅ与糖皮质激素用药时间呈显著负相关（ｒ＝－０．５８，Ｐ＝０．００３，ｎ＝２３）。提示绝经后女性ＲＡ患者存在明显的骨质丢失。     

沈阳地区绝经后妇女绝经年限与股骨近端骨密度的关系分析

目的 探讨绝经年限与股骨近端BMD的关系。方法 随机调查沈阳地区285例健康的绝经后妇女，调查其年龄和绝经年限，测量其身高、体重、股骨近端骨密度(BMD)，应用SPSS软件统计分析。结果 随绝经年限的增加股骨近端各部位BMD有下降的趋势，随绝经年限的增加股骨近端各部位BMD下降速度减慢，并且相对而言Neck、Ward’s区的BMD下降速度高于其他部位。以年龄和体重指数(BMI)为协变量，经协方差分析显示Ward’s区BMD与绝经年限具有显著相关，而其他部位无显著相关。结论 对绝经后妇女应注意绝经早期的股骨近端BMD变化。     

Cross-sectional geometry, bone strength, and bone mass in the proximal femur in black and white postmenopausal women.

Osteoporosis is characterized by both a low bone mass and a disruption of the architectural arrangement of bone tissue, leading to decreased skeletal strength and increased fracture risk. Although there are well-known ethnic differences in bone mass and fracture risk, little is known about possible ethnic differences in bone structure. Therefore, we studied cross-sectional geometry in the hip in a sample of postmenopausal black and white women in order to investigate ethnic differences that might contribute to differences in bone strength and ultimately hip fracture risk. We recruited 371 postmenopausal black and white women who were entering the Women's Health Initiative (WHI) clinical trials in Detroit. Bone density measurements of the proximal femur were done by dual-energy X-ray absorptiometry (DXA) using a Hologic 1000 Plus bone densitometer. The DXA data were used for hip structure analysis, which treats the entire proximal femur as a continuous curved beam from the proximal shaft to the femoral neck. This permits the analysis of cross-sectional geometric properties in two narrow regions corresponding to thin (5 mm) cross-sectional slabs seen on edge. The results indicate significant ethnic differences in bone density, cross-sectional geometry, and dimensional variables. Specifically, the black women have a significantly higher bone density in both locations (10.1% and 4.1% for the neck and shaft, respectively); greater cross-sectional geometric properties in the neck (ranging from 6.1% to 11.6%), but a smaller endocortical diameter in the neck (3.6%). There are fewer significant differences in cross-sectional geometry in the shaft location. Our data suggest that the spatial distribution of bone is arranged in the femoral neck to resist greater loading in black women compared with white women.     

Menopause-related changes in bone mineral density in Japanese women: A longitudinal study on lumbar spine and proximal femur

We investigated 2-year longitudinal changes of bone mineral density (BMD) in lumbar spine and proximal femur in 64 Japanese women aged 38–67. Forty subjects were premenopausal (mean age 44.9) and 24 postmenopausal (mean age 54.6) at enrollment of the study. Six subjects experienced menopause during the 2-year study period and were defined as the perimenopausal group. Measurements of BMD were performed using dual-energy X-ray absorptiometry at L2–4, femoral neck, greater trochanter, and Ward's triangle. Paired t test revealed no significant decrease in BMD at any site in the premenopausal group. Significant annual decrease in BMD was observed in the perimenopausal group at L2–4, femoral neck, and greater trochanter. A similar tendency was observed in Ward's triangle, but did not reach statistical significance. In the postmenopausal group, significant decrease in BMD was found at the proximal femur, but not at L2–4. Significant inverse correlation between age and change rate of BMD was found at L2–4, but not at the proximal femur, in premenopausal women. In postmenopausal women, there was a significant association between body weight (BW) change and change rate in BMD at L2–4, femoral neck, or greater trochanter. This association was not found in the premenopausal group. These results suggest that effect of menopause on BMD may be different in individuals and sites of the skeleton. BW change may affect change in BMD in postmenopausal women. However, the limited variability in both BW and BMD changes among premenopausal women in this study may explain the poor association between change in BW and change in BMD in the premenopausal group. As individual differences in each group is considerably large, annual measurements of BMD may be necessary to find possible candidates for early intervention.     

Structural and remodeling indices in the cancellous bone of the proximal femur across adulthood

Fragility fractures, including fractures of the femoral neck, result from reductions in the amount, quality and architecture of bone. However, investigations of the underlying structural changes that might predispose to fracture have been largely limited to skeletal sites that do not fracture, such as the iliac crest (IC). The aim of this study was to use histomorphometry to map changes in the architecture and the static remodeling indices of cancellous bone, as a function of age and sex, in bone samples taken from the intertrochanteric (IT) region of the proximal femur at routine autopsy (18-88 years of age). Bone samples for histology were processed from 10-mm cubes of IT cancellous bone. Histomorphometry was performed using an ocular-mounted 10 x 10 graticule at a magnification of x100. An age-dependent decrease in trabecular bone volume was observed in both females and males, as expected (r=-0.75 and r=-0.63, p<0.001, respectively). The underlying mechanisms for bone turnover appeared to be different between males and females. Thus, while the static index of bone resorption (ES/BV) was positively age-dependent in males and females (p<0.001, p<0.03, respectively), the index of bone formation (OS/BV) correlated positively with age in the female group only (p<0.001 vs. NS). Perhaps reflecting an increase in bone formation in older females, the OS/ES ratio was greater in older females than younger females or males. Surprisingly, while resorption indices increased in older males compared with their younger counterparts, bone formation indices increased only in the older female cohort. The IT region in the proximal femur is adjacent to the site commonly involved in fragility fracture. With the limitation that these results describe cross-sectional data, they provide useful insights into changes in the cancellous bone structure and at the bone surface of females and males over the age range of 20-90 years, at a clinically relevant skeletal site.     

Age trends in proximal femur geometry in men: variation by race and ethnicity

Summary Data on bone architecture in diverse male populations are limited. We examined proximal femur geometry in 1,190 black, Hispanic, and white men. Cross-sectional analyses indicate greatest bone strength among black men, and greater age-related differences in bone strength among Hispanic men than other subjects at the narrow neck and intertrochanter regions of the proximal femur. Introduction Although race/ethnic differences in bone mass are well-documented, less is known about differences in bone architecture. We examined proximal femur geometry in a diverse, randomly-sampled population of 1,190 community-dwelling men (age 30–79 y). Methods Dual X-ray absorptiometry scans were obtained for 355 black, 394 Hispanic, and 441 white subjects. Measures were obtained for the narrow neck (NN), intertrochanter (IT) and shaft regions of the proximal femur via hip structural analysis. Analyses considered bone mineral density (BMD, g/cm²), outer diameter (cm), cross-sectional area (CSA, cm²), section modulus (Z, cm³), and buckling ratio (BR). Results were adjusted for height, weight and physical activity level. Results Black subjects exhibited greater age-specific BMD, CSA and Z, than their white counterparts. For instance, at age 50 y, NN BMD was approximately 11% higher among black men (p < 0.001). Hispanic men exhibited sharper age-related differences in NN and IT BMD than did others. IT BMD, for instance, decreased by 2.4% with 10 y age among Hispanic subjects, but had virtually no age trend in others (p < 0.001). Conclusions These results imply greater bone strength among black American men than among their white counterparts, and may indicate elevated fracture risk among older Hispanic American subpopulations. Grant support: The BACH/Bone study was supported by grant AG 20727 from the National Institute on Aging (NIA). The parent study (BACH) was supported by grant DK 56842 from the National Institute of Diabetes and Digestive and Kidney Diseases.     

围绝经期妇女血清铁蛋白水平和股骨颈骨强度相关性研究

目的探索围绝经期妇女血清铁蛋白与股骨颈强度综合指数之间的关系。方法选择2014年7月至2017年12月在我院就诊的116例围绝经期妇女纳入本研究。使用双能X射线吸收扫描仪测量髋部骨几何结构性质,包括髋轴长度(HAL)和股骨颈宽度(FNW),并将其与BMD,体重和身高结合以产生股骨颈的综合指数(CSI)、弯曲(BSI)和冲击强度指数(ISI)三种不同的失效模式下的强度。结果在对年龄、体质量指数(BMI)、生活方式因素、血清25-羟基维生素D、钙和磷摄入量、糖尿病和更年期状态进行校正后,多元回归分析显示血清铁蛋白与腰椎和股骨颈,以及股骨颈皮质厚度密切相关。重要的是,在所有的调整模型中,血清铁蛋白与三种股骨颈综合指数(如CSI、BSI和ISI)显示负相关(P0.05)。结论本研究表明高血清铁蛋白反映的全身铁储存增加可能与骨强度相对于负荷的减少有关。     

Bone mineral density behavior of proximal femur in women with vertebral fractures

When radiological evidence for vertebral osteoporosis exists, it is more prudent to perform proximal femur DEXA measurements given the limitations in the interpretation of vertebral BMD results.     

增龄对大鼠股骨上端BMP-2基因表达的影响

目的 了解增龄变化对大鼠股骨上端BMP-2基因表达的影响，分析BMP-2基因表达与老年性骨质疏松发病的相互关系。方法 随机选取4，8，12，16及22月龄大鼠各3只，应用RT-PCR技术检测其股骨上端BMP-2的基因表达情况。结果 4～8月龄的大鼠股骨上端BMP-2基因表达逐渐升高；8～12月龄时进入平台期；12～16月龄时开始逐步下降。22月龄大鼠BMP-2基因表达较12月龄大鼠显著下降。结论 BMP-2基因表达具有明显的年龄相关性，老龄时BMP-2基因表达明显降低可能是老年性骨质疏松发病的重要原因之一。     

Age-related changes in bone density, geometry and biomechanical properties of the proximal femur: CT-based 3D hip structure analysis in normal postmenopausal women

The geometry as well as bone mineral density (BMD) of the proximal femur contributes to fracture risk. How and the extent to which they change due to natural aging is not fully understood. We assessed BMD and geometry in the femoral neck and shaft separately, in 59 normal Japanese postmenopausal women aged 54-84 years, using clinical computed tomography (CT) and commercially available software, at baseline and 2-year follow-up. This system detected significant reductions over the 2-year interval in total BMD (%change/year = -0.900 ± 0.257, p < 0.0005), cortical cross-sectional area (CSA) (-0.800 ± 0.423%/year, p < 0.05) and cortical thickness (-1.120 ± 0.453%/year, p < 0.01) in the femoral neck. In the femoral shaft, cortical BMD decreased significantly (-0.642 ± 0.188%/year, p < 0.005). Regarding biomechanical parameters in the femoral neck, the cross-sectional moment of inertia (CSMI) and section modulus (SM) decreased (-1.38 ± 3.65%/year, p < 0.01 and -1.37 ± 2.96%/year, p < 0.005) and the buckling ratio (BR) increased significantly (1.48 ± 4.81%/year, p < 0.05), whereas no changes were found in the femoral shaft. The distinct patterns of age-related changes in the geometry and biomechanical properties in the femoral neck and shaft suggest that improved geometric measures are possible with the current non-invasive method using clinical CT.     

Cost-effectiveness analysis of screening for osteoporosis in postmenopausal Japanese women

 Osteoporosis-related hip fracture is an important cause of mortality and morbidity in older people. In an aging society such as Japan's, prevention and treatment of osteoporosis is of paramount importance in reducing the risk of hip fracture. To determine the efficiency of screening by dual-energy X-ray absorptiometry for reducing the incidence of hip fracture, a cost-effectiveness analysis was conducted using a state-transition model. We compared the following four strategies in a hypothetical cohort of postmenopausal Japanese women: (1) no intervention; (2) hormone replacement therapy (HRT) for patients with osteoporosis after screening; (3) HRT for patients with osteopenia and osteoporosis after screening; and (4) universal HRT. Epidemiological and economic data were collected from published articles. HRT for patients with osteoporosis after screening was the most cost-effective strategy, with the marginal cost-effectiveness being 5.36 million yen/quality-adjusted life year (QALY). The ratios for other strategies exceeded 10 million yen/QALY. Sensitivity analyses showed that the drug effect and treatment cost of HRT had a significant influence on the results. Screening postmenopausal Japanese women and treating patients with osteoporosis may be an acceptable strategy, but its cost-effectiveness ratio seems only fair at present. Received: January 30, 2002 / Accepted: March 22, 2002 Offprint requests to: T. Fukui     

A biomechanical study comparing proximal femur nail and proximal femur locking compression plate in fixation of reverse oblique proximal femur fractures

BackgroundThe reverse oblique trochanteric fractures are common fractures and its treatment poses a challenge. The purpose of this study was to compare the biomechanical parameters of the construct using proximal femoral nail (PFN) and proximal femoral locking compression plates (PFLCP) in these fractures using cadaveric specimens.Materials and MethodsTwenty freshly harvested cadaveric femoral specimens were randomly assigned to two groups after measuring bone mineral density, ten of which were implanted with PFN and the other ten with PFLCP. The constructs were made unstable to simulate reverse oblique trochanteric fracture (AO type 31A3.3) by removing a standard size posteromedial wedge. These constructs were tested in a computer controlled cyclic compressive loading with 200 kg at a frequency of 1 cycle/s (1 Hz) and test was observed for 50,000 cycles or until implant failure, whichever occurred earlier. Peak displacements were measured and analysis was done to determine axial stiffness and subsidence in axial loading.ResultsAll the specimens in PFN group completed 50,000 cycles and in PFLCP group, seven specimens completed 50,000 cycles. Average subsidence in PFN group was 1.24 ± 0.22 mm and in PFLCP group was 1.48 ± 0.38 mm. The average stiffness of PFN group (72.6 ± 6.8 N/mm) was significantly higher than of PFLCP group (62.4 ± 4.9 N/mm) (P = 0.04). The average number of cycles sustained by PFLCP was 46634 and for PFN group was 50,000 (P = 0.06).ConclusionThe PFN is biomechanically superior to PFLCP in terms of axial stiffness, subsidence and number of specimens failed for the fixation of reverse oblique trochanteric fractures of femur.     

Long proximal femoral nail in ipsilateral fractures proximal femur and shaft of femur

Background:

Ipsilateral fractures of the proximal femur and femoral shaft are extremely uncommon injuries which occur in young adults who sustain a high energy trauma. A variety of management modalities have been tried to treat this complex fracture pattern ranging from conservative approach to recently introduced reconstruction nails. All these approaches have their own difficulties. We studied the outcome of long proximal femoral nail (LPFN) in the management of concomitant ipsilateral fracture of the proximal femur and femoral shaft.

Materials and Methods:

We analysed the prospective data of 36 consecutive patients who had sustained a high energy trauma (30 closed fractures and 6 open shaft fractures) who had concomitant ipsilateral fractures of the femoral shaft associated with proximal femur fractures treated with LPFN between December 2005 and December 2011. The mean age was 39 years (range 28-64 years). Twenty nine males and seven females were enrolled for this study.

Results:

The patients were followed up at three, six, twelve, and eighteen months. The mean healing time for the neck fractures was 4.8 months and for the shaft fractures was 6.2 months. The greater trochanter was splintered and widened in two cases which eventually consolidated. Two patients had superficial infection, two patients had lateral migration of the screws with coxa vara which was due to severe osteoporosis detected during the followup. We had two cases of nonunion of shaft fracture and one case of nonunion of neck fracture. Two cases of avascular necrosis of femoral head were detected after 2 years of followup. No cases of implant failure were noted. Limb shortening of less than 2 cms was noted in four of our patients. The functional assessment system of Friedman and Wyman was used for evaluating the results. In our series 59.9% (n = 23) were rated as good, 30.6% (n = 11) as fair, and 5.5% (n = 2) as poor.

Conclusion:

Long PFN is a reliable option for concomitant ipsilateral diaphyseal and proximal femur fractures.