Bone
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Dual-energy X-ray absorptiometry (DXA) allows clinically relevant measurement of bone mineral density (BMD) at central and appendicular skeletal sites, but DXA has a limited ability to assess bone geometry and cannot distinguish between the cortical and trabecular bone compartments. Quantitative computed tomography (QCT) can supplement DXA by enabling geometric and compartmental bone assessments. Whole-body spiral CT scanners are widely available and require only seconds per scan, in contrast to peripheral QCT scanners, which have restricted availability, limited spatial resolution, and require several minutes of scanning time. This study evaluated the accuracy and precision of whole-body spiral CT scanners for quantitatively assessing the distal radius, a common site of non-vertebral osteoporosis-related fractures, and compared the CT-measured densitometric values with those obtained from dual-energy-X-ray absorptiometry. ⋯ Whole-body spiral CT scanners allow densitometric evaluations of the distal radius with good accuracy and very good precision. This original and convenient method provides a tool to further investigate cortical and trabecular bone variables in the peripheral skeleton in osteoporotic patients. These assessments, coupled with evaluation of the effects on cortical and trabecular bone measured in response to therapies for osteoporosis, may advance our understanding of the contributors to non-vertebral fracture occurrence.
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Osteoporosis is a major health problem characterized by compromised bone strength that predisposes patients to an increased risk of fracture, more and more investigations are focusing on the treatment of osteoporotic fracture healing. However, there are few studies elucidating the efficacy of vitamin D, 1,25-dihydroxy vitamin D(3) (1,25(OH)(2)D(3)), on osteoporotic fracture healing. In the present study we have established an osteoporotic fracture rat model to evaluate the effects of 1,25(OH)(2)D(3) on fracture healing. ⋯ At 16 weeks post-fracture, the ultimate load and energy absorption were also higher with the treatment of 1,25(OH)(2)D(3) (P<0.01 vs control). Histology showed that the fracture callus in the 1,25(OH)(2)D(3) group was remodeled better compared to the control group. In conclusion, 1,25(OH)(2)D(3) could promote fracture healing by improving the histomorphometric parameters, mechanical strength and tendency to increase transformation of woven bone into lamellar bone in an ovariectomized rat model.
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Low-trauma fractures of older women are a major public health problem. Nevertheless, nationwide information on recent trends of proximal humeral fractures is sparse. ⋯ In conclusion, the clear rise in the rate of low-trauma fractures of the proximal humerus in Finnish elderly women from early 1970s until mid 1990s has been followed by stabilized fracture rates. Reasons for this are largely unknown, but a cohort effect toward a healthier aging population with improved functional ability and reduced risk of injurious falls cannot be ruled out.
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We identified regions inside the proximal femur that are most strongly associated with hip fracture. Bone densitometry based on such fracture-critical regions showed improved power in discriminating fracture patients from controls. ⋯ We have identified the sub-volumes of proximal femoral tissue which have the strongest association with hip fracture. The power to predict fracture can be improved, by focusing on BMD measurements in the fracture-critical regions, rather than in standard ROIs.
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Fracture healing is thought to be naturally optimized; however, recent evidence indicates that it may be manipulated to occur at a faster rate. This has implications for the duration of morbidity associated with bone injuries. Two interventions found to accelerate fracture healing processes are recombinant human parathyroid hormone [1-34] (PTH) and low-intensity pulsed ultrasound (LIPUS). ⋯ In contrast, the effect of PTH on callus BMC but not TV resulted in increased callus vBMD and a more mature callus. This resulted in PTH increasing fracture site mechanical strength and stiffness. These data suggest that PTH may have utility in the treatment of acute bone fractures, whereas LIPUS at an I(SATA) of 100 mW/cm(2) does not appear to be indicated in the management of closed, diaphyseal fractures.