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Query: UNIPROT:P50502 (Hip)
 7,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Osteoporosis is a major clinical problem in older women and men. Almost any bone can fracture as a result of the increased bone fragility of osteoporosis. These fractures are associated with higher health care costs, physical disability, impaired quality of life, and increased mortality. Because the incidence of osteoporotic fracture increases with advancing age, measures to diagnose and prevent osteoporosis and its complications assume a major public health concern. BMD is a valuable tool to identify patients at risk for fracture, to make therapeutic decisions, and to monitor therapy. Several other modifiable and nonmodifiable risk factors for osteoporosis have also been identified. Treatment of potentially modifiable risk factors along with exercise and calcium and vitamin D supplementation forms an important adjunct to pharmacologic management of osteoporosis. Improved household safety can reduce the risk of falls. Hip protectors have been found to be effective in nursing home population. The pharmacologic options include bisphosphonates, HRT, SERMs and calcitonin. PTH had received FDA advisory committee approval. Alendronate has been approved for treatment of osteoporosis in men, and other treatments for men are under evaluation.
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PMID:Osteoporosis in elderly: prevention and treatment. 1242 71

To differentiate changes in trabecular and cortical bone density at a skeletal site bearing body weight, the main goal of this retrospective study was to develop and characterize two new regions of interest (ROIs) for DXA at the hip, one mainly focusing on trabecular bone and another mainly focusing on cortical bone. Specific aims were to maximize the precision of the ROIs and to characterize their usefulness for monitoring age-related bone loss and discriminating controls from fracture cases in a cross-sectional study population and to compare them with earlier ROIs designed by our group. The study used populations from two different previous studies conducted in our laboratory, with one comprising cohorts of healthy premenopausal women, healthy postmenopausal women, and postmenopausal osteoporotic women with at least one spinal fracture (Spine Fx Study) and the other one comprising two cohorts of age-matched postmenopausal women, in whom cases had sustained a hip fracture (Hip Fx study). The new ROI for trabecular bone (CIRCROI) tries to improve on the earlier custom-designed Central ROI, which was also targeted at trabecular bone. CIRCROI consists of an approximate largest circle that can fit inside the femoral proximal metaphysis without touching the superior and inferior endocortical walls. The new ROI for cortical bone (CORTROI) at a site bearing body weight is defined as a horizontal rectangular box crossing the femoral shaft below the lesser trochanter. CORTROI BMD cohort means were significantly higher than all other ROIs, and CIRCROI BMD cohort means were lower than standard ROIs with the exception of Ward's ROI. CIRCROI BMD was highly correlated with total femur BMD ( r=0.94) and Central BMD ( r=0.93), whereas CORTROI BMD correlations were lower (highest with total femur BMD ( r=0.86)). Fracture discrimination odds ratios (ORs) of all ROIs were significant for the Hip Fx Study, with CIRCROI BMD having the highest, and CORTROI BMD the lowest, OR (4.83 and 2.49 per SD, respectively, compared with 3.69 for Ward's ROI as the highest OR of standard ROIs). For the Spine Fx Study, only spinal and trochanteric BMD had significant OR. The new trabecular ROI had good short-term precision, comparable to the standard ROIs at the hip, but improving on that of Ward's triangle, the only standard ROI only including the anterior and posterior cortical walls and therefore more predominantly consisting of trabecular bone than other standard ROIs. The precision of the new cortical ROI was lower than standard DXA ROIs, except for Ward's triangle, but provides unique information on purely cortical bone at a skeletal site bearing body weight.
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PMID:Two new regions of interest to evaluate separately cortical and trabecular BMD in the proximal femur using DXA. 1459 25

A major determinant of osteoporotic hip fracture is peak hip BMD which is a highly heritable trait. Caucasian American women have lower BMD and higher hip fracture rates than African American women. This study examines linkage of hip BMD in 570 Caucasian sister pairs and 204 African American sister pairs. It compares the results with our published study in a smaller overlapping sample of Caucasian sisters. Hip BMD was measured at neck, trochanter, Ward's, shaft, and total hip. Principal component analysis provided a novel BMD phenotype comprising neck and trochanter, common sites of fracture, and Ward's, site of lowest BMD. A 9 cM genome scan was performed for these phenotypes. Significant linkage was found at chromosomes 14q and 15q. At 14q, the 774 African American and Caucasian sister pairs together yielded the highest LOD score for trochanter (3.5) and at 15q the highest LOD score for femoral neck (4.3). This linkage study in Caucasian and African American healthy premenopausal sisters demonstrates that chromosomes 14q and 15q harbor genes that affect peak bone mass at the hip in women. Principal component had comparable LOD scores with those of the component phenotypes suggesting pleiotropic effects of these genes on hip phenotypes.
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PMID:Peak bone mineral density at the hip is linked to chromosomes 14q and 15q. 1520 21

Measures of musculoskeletal rehabilitation play an integral part in the management of patients with increased fracture risk because of osteoporosis or extraskeletal risk factors. This article delineates current scientific evidence concerning nonpharmacologic approaches that are used in conjunction with pharmacotherapy for prevention and management of osteoporosis. Fractures caused by osteoporotic fragility may be prevented with multidisciplinary intervention programs, including education, environmental modifications, aids, and implementation of individually tailored exercise programs, which are proved to reduce falls and fall-related injuries. In addition, strengthening of the paraspinal muscles may not only maintain BMD but also reduce the risk of vertebral fractures. Given the strong interaction between osteoporosis and falls, selection of patients for prevention of fracture should be based on bone-related factors and on risk factors for falls. Rehabilitation after vertebral fracture includes proprioceptive dynamic posture training, which decreases kyphotic posturing through recruitment of back extensors and thus reduces pain, improves mobility, and leads to a better quality of life. A newly developed orthosis increases back extensor strength and decreases body sway as a risk factor for falls and fall-related fractures. Hip fractures may be prevented by hip protectors, and exercise programs can improve strength and mobility in patients with hip fracture. So far, there is no conclusive evidence that coordinated multidisciplinary inpatient rehabilitation is more effective than conventional hospital care with no rehabilitation professionals involved for older patients with hip fracture. Further studies are needed to evaluate the effect of combined bone- and fall-directed strategies in patients with osteoporosis and an increased propensity to falls.
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PMID:Musculoskeletal rehabilitation in osteoporosis: a review. 1523 Oct 6

Nitric oxide (NO) is an important bone-signaling molecule. We examined the associations between the Glu298Asp polymorphism of NOS3, indices of bone strength, and the incidence of fracture among 6691 women aged 65 years and older enrolled in the Study of Osteoporotic Fractures. Calcaneal BMD was measured at an initial exam and after an average of 5.9 years of follow-up. Hip BMD was measured at an initial exam and after 3.7 years of follow-up. Baseline spine BMD and hip structural parameters were measured. Incident hip fractures were confirmed by review of radiographic reports; follow-up was greater than 98% complete. Incident vertebral fractures were defined by morphometry using lateral spine radiography at baseline and an average of 3.7 years later. The frequencies of the NOS3 Glu298Asp genotypes were Glu/Glu=46.2%, Glu/Asp=42.7%, and Asp/Asp=11.1%. There were no significant associations between NOS3 genotypes and initial calcaneal BMD, hip BMD, or rate of change in hip or calcaneal BMD. None of the hip structural parameters differed substantially by genotype. NOS3 genotype was not significantly associated with either incident or prevalent radiographic vertebral fractures. Women with the heterozygous Glu/Asp genotype had a borderline statistically significantly lower rate of hip fracture than either the Glu/Glu genotype (HR=0.87, 95% CI: 0.74, 1.01) or the Asp/Asp genotype (HR=0.78, 95% CI: 0.62, 0.98). In conclusion, the Glu298Asp polymorphism does not contribute substantially or consistently to indices of bone strength in this sample of older white women, although our findings suggest allelic variation at the NOS3 locus maybe associated with hip fracture risk. Confirmation of these findings is needed in other populations and with additional markers within and flanking the NOS3 gene region.
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PMID:Association of endothelial nitric oxide synthase genotypes with bone mineral density, bone loss, hip structure, and risk of fracture in older women: the SOF study. 1650 13

Hip fractures due to osteoporosis are accompanied with increased mortality and morbidity. Bone mineral density (BMD [g/cm(2)]) measured by dual-energy X-ray absorptiometry (DXA) is the most important risk factor. However, an overlap exists between results of fractured and nonfractured populations. Macro-architectural parameters of the femur are independent risk factors of fracture. They have been evaluated in two dimensions using X-ray films or DXA scans; therefore, they are highly dependent on patient positioning and interindividual anatomical variations. To overcome this problem, we have previously shown the possibility to reconstruct human femurs using two perpendicular DXA scans and to calculate 3-dimensional (3D) geometric parameters from these reconstructions by a method called 3-dimensional X-ray absorptiometry (3D-XA). The aim of this article is to assess whether the combination of areal BMD and 3D geometric parameters calculated from 3D-XA improves failure load prediction of human proximal femurs in stance phase configuration. Twelve femurs (11 women, 1 man; aged 88+/-9 yr; range: 72-103 yr) were included in this study. The BMD was measured using a Hologic Delphi-W device (Hologic, Waltham, MA) and 3D reconstruction of the femurs was done using two perpendicular DXA scans as previously published. The calculated 3D geometric parameters included femoral neck axis length (FNAL), mid-femoral neck cross-sectional area (mid-FN CSA), neck shaft angle (NSA), and femoral head diameter (FHD). Mechanical testing was performed using stance phase configuration, which resulted in subcapital fractures. The FHD was correlated to mid-FN CSA and FNAL (r=0.68 and 0.76, respectively; p<0.001). Failure load was correlated to age, FHD, NSA, and BMD measurements. Multiple regression analysis showed that femoral neck BMD, FHD, and mid-FN CSA gave the best statistical model for failure load prediction (r(2)=0.84; p<0.002). This is the first study suggesting that combining areal BMD to 3D geometric parameters obtained by 3D-XA improve failure load prediction in human femurs.
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PMID:Assessment of femoral neck strength by 3-dimensional X-ray absorptiometry. 1709 28

Hip structure analysis (HSA) can be used to measure proximal femur geometry using conventional DXA scans of the hip. This study is the first analysis of HSA data in Japanese women to evaluate apparent age trends in the geometry of cross-sectional regions in the proximal femur. 409 Japanese women aged from 50 to 93 years of age were measured by DXA at three sites (narrow neck, intertrochanter, shaft). Using the mean value those between 50-59 years as a reference value, age trends were evaluated using groupings of 5-year intervals and those over 80 as a single group. BMD at three measured sites and section modulus (index of bending strength) at narrow neck declined in a similar age dependent manner, but section modulus at intertrochanter and shaft showed a different pattern. The decline in section modulus at narrow neck occurs after 50-59 years of age, whereas section modulus at intertrochanter remain 70-74 years, after that began to decrease. Section modulus at shaft, an uncommon fracture location, remains fairly static through life. In conclusion, HSA in Japanese women showed that reduction in geometric strength, as reflected by the section modulus, was not dependent on decline in BMD.
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PMID:Structural trends in the aging proximal femur in Japanese postmenopausal women. 1751 85

Hip structural analysis (HSA) estimates geometrical and mechanical properties from hip dual-energy X-ray absorptiometry (DXA) images and is widely used in osteoporosis trials. This study compares HSA to volumetric quantitative computed tomography (QCT) measurements in the same population. A total of 121 women (mean age 58 yr, mean body mass index 27 kg/m2) participated. Each woman received a volumetric QCT scan and DXA scan of the left hip. QCT scans were analyzed with in-house software that directly computed geometric and mechanical parameters at the neck and trochanteric regions. DXA HSA was performed with an implementation by GE/Lunar. Pair-wise linear regression of HSA variables was conducted by method to site matched QCT variables for bone density, cross-sectional area, and cross-sectional moment of inertia (CSMI) of the femur neck. HSA correlated well with QCT (r2=0.67 for neck bone mineral density [BMD] and 0.5 for CSMI) and standard DXA at the neck (r2=0.82 for BMD). HSA and volumetric QCT compared favorably, which supports the validity of a projective technique such as DXA to derive geometrical properties of the proximal hip.
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PMID:Comparison of DXA hip structural analysis with volumetric QCT. 1926 99

Proximal femur fractures are of main concern for elderly and especially osteoporotic patients. Despite advanced implant modifications and surgical techniques, serious mechanical complication rates between 4-18% are found in conventional osteosyntheses of proximal femur fractures. Clinical complications such as the rotation of the femoral head and the cut-out phenomenon of the fracture fixation bolt are often diagnosed during post-operative treatments. Therefore, efforts in new intramedulary techniques focus on the load bearing characteristics of the implant by developing new geometries to improve the implant-tissue interface. The objective of this investigation was to analyse the osteosynthesis/femur head interaction of two commonly used osteosyntheses, one with a helical blade and the other one with a screw design under different loading conditions. For the comparative investigation the helical blade of the Proximal Femur Nail Antirotation was investigated versus the screw system of the Dynamic Hip Screw. After implantation in a femoral head the loads for rotational overwinding of the implants were analysed. Pull-out forces with suppressed rotation were investigated with analysis of the influence of the previous overwinding. All investigations were performed on human femoral heads taken of patients with average age of 70.3+/-11.8. The bone mineral densities of the human specimens were detected by QCT-scans (average BMD: 338.9+/- 61.3$\frac[\mathit[mg]][\mathit[cm];[3]]$) Prior to cadaveric testing the experimental set-up was validated and special influences were analysed by the use of synthetic foam blocks (Sawbone). The helical blade showed a significant higher torque for the rotation of the femoral head compared to the screw system. The pull-out forces of the blade were substantially lower than of the comparative screw. Taken together the helical blade showed a higher potential of rotational stability, but after a rotation the lower pull-out forces demonstrate a higher degree of damage to the femoral head.
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PMID:Biomechanical characterisation of osteosyntheses for proximal femur fractures: helical blade versus screw. 1837 8

Lead is stored in the skeleton and can serve as an endogenous source for many years. Lead may influence the risk of fracture, through direct effects on bone strength or indirectly by disturbing neuromuscular function and increasing the risk of falls. The objective of this analysis is to test the hypothesis that women with higher blood lead levels experience higher rates of falls and fracture. This was a prospective cohort study of 533 women 65-87 yr of age enrolled in the Study of Osteoporotic Fractures at two U.S. research centers (Baltimore, MD; Monongahela Valley, PA) from 1986 to 1988. Blood lead levels (in microg/dl) were measured in 1990-1991 by atomic absorption spectrophotometry and classified as "low" (<or=3; lower 15th percentile, referent); "medium" (4-7); or "high" (>or=8; upper 15th percentile). Total hip BMD was measured by DXA twice, 3.55 yr apart. Information on falls was collected every 4 mo for 4 yr. Incident nonspine fractures were identified and confirmed over 10 yr. Cox proportional hazards models were used to estimate the hazard ratio (HR) and 95% CI of fracture. Generalized estimating equations were used to calculate the incident rate ratio of falls (95% CI). The mean blood lead level was 5.3 +/- 2.3 (SD) microg/dl (range, 1-21 microg/dl). Baseline BMD was 7% lower in total hip and 5% lower in femoral neck in the highest compared with lowest blood lead group (p < 0.02). Hip bone loss tended to be greater in the high lead group, but differences were not significant. In multivariable adjusted models, women with high blood lead levels had an increased risk of nonspine fracture (HR = 2.50; 95% CI = 1.25, 5.03; p trend = 0.016) and higher risk of falls (incident rate ratio = 1.62; 95% CI = 1.07, 2.45; p trend = 0.014) compared with women with lowest lead level. Blood lead levels are associated with an increased risk of falls and fractures, extending the negative health consequences of lead to include osteoporotic fractures.
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PMID:Relationship of blood lead levels to incident nonspine fractures and falls in older women: the study of osteoporotic fractures. 1841 Feb 30


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