The ability of current clinical tools to predict bone fractures is poor, likely because these tools focus on bone mass and mineral content and neglect bone quality and the collagen phase. The Mechanical Response Tissue Analyzer (MRTA) is an instrument that provides a non-invasive mechanical measurement of the whole bone. It has traditionally been used to obtain a bone stiffness constant (Kb), but can provide a bone damping constant (Bb) that has not previously been considered. The goal of this research is to determine whether the MRTA can detect three damage modes that do not alter bone mass or mineral density: γ-irradiation, collagen over-crosslinking, and fatigue. The MRTA detected a reduction in Bb due to over-crosslinking. Fatigue was found to increase Bb and decrease Kb, and these changes were confirmed through dynamic bending tests. The MRTA shows potential to diagnose increased fracture risk in scenarios where damage is currently undetectable.

The ability of current clinical tools to predict bone fractures is poor, likely because these tools focus on bone mass and mineral content and neglect bone quality and the collagen phase. The Mechanical Response Tissue Analyzer (MRTA) is an instrument that provides a non-invasive mechanical measurement of the whole bone. It has traditionally been used to obtain a bone stiffness constant (Kb), but can provide a bone damping constant (Bb) that has not previously been considered. The goal of this research is to determine whether the MRTA can detect three damage modes that do not alter bone mass or mineral density: γ-irradiation, collagen over-crosslinking, and fatigue. The MRTA detected a reduction in Bb due to over-crosslinking. Fatigue was found to increase Bb and decrease Kb, and these changes were confirmed through dynamic bending tests. The MRTA shows potential to diagnose increased fracture risk in scenarios where damage is currently undetectable.

Hip fracture has been identified as one of the main health problems in the elderly. To improve the accuracy in assessing subject-specific hip fracture risk, this study proposed normalized cortical bone thickness (NCBT) estimated from patient’s hip DXA as an alternative predictor of hip fracture risk. Hip fracture risk index (HFRI) derived from DXA-based finite element model was utilized as a baseline for evaluating the effectiveness of NCBT in predicting hip fracture risk. It was found that NCBT at the lateral side of the narrowest femoral neck had the strongest correlation with femoral neck HFRI among the six locations of the proximal femur. This study suggests that it is possible to use NCBT as a surrogate for a quick evaluation of hip fracture risk. Yet its clinical performances such as sensitivity to therapy effectiveness and the ability to discriminate clinical fracture cases will be investigated in a future study.

No description available.

[Truncated abstract] The cost of managing osteoporotic fractures places a significant financial burden on the health-care system. To reduce the fracture burden, early identification of fracture risk is essential to allow early intervention. The limitations associated with dual-energy X-ray absorptiometry (DXA), such as limited sensitivity and specificity, cost, ionising radiation and accessibility, have resulted in the emergence of other technologies for assessing bone fragility. An example is the portable and non-ionising quantitative ultrasound (QUS) technology. The discriminatory power of quantitative ultrasonometry in fracture risk identification, either independently or in combination with other established risk factors, currently remains contentious. It is recommended that fracture risk assessment should not only focus on bone status, but also on the risk of falls. Additionally, it has been noted that disability arising from osteoporotic fractures, even when these fractures are not identified clinically, can translate into psychosocial symptoms and a poorer perception of health-related quality of life (HRQoL). The primary aim of the present study was to investigate if a composite model comprising: calcaneal QUS, falls risk and HRQoL assessments, can identify a group of elderly women at high risk of osteoporotic fracture from those at lower risk. One hundred and four community-dwelling women (mean age 71.3 ±5.8 years) were recruited for this study. These women underwent a series of tests that included: DXA bone mineral density (BMD) evaluation of the proximal femur and lumbar spine (L1 L4); calcaneal QUS measurement; spinal radiography; rasterstereographic back surface curvature (BSC) examination; and performance-based assessment of strength, mobility and balance. The women were classified into a `High Risk’group or a `Low Risk’ group using three separate classification criteria: i) low BMD, based on the World Health Organisation (WHO) recommended T-score of < -2.5, and⁄or a history of fragility fracture (Osteoporotic [OP] group versus Non-Osteoporotic [NOP] group); ii) presence of at least one radiographically identified prevalent vertebral fracture (Vertebral Fracture [VF] group versus Non-Vertebral Fracture [NVF] group); or iii) a history of either forearm or wrist fracture (Forearm/Wrist Fracture [WF] group versus Non-Forearm/Wrist Fracture [NWF] group)

Fracture risk reduction is the main goal of treating osteoporosis, a condition which, in the absence of fragility fractures, is diagnosed by bone densitometry. Bone density, however, although an important factor predicting fracture risk, is not the only one and several other factors modulate the fracture risk such as the patient's age, body mass index, family history, cigarette smoking, medications and the risk of falling: most fractures are preceded by falls. When developing a treatment strategy it is therefore important to take into consideration other factors apart from bone density. Several algorithms and instruments are available for this purpose. The FRAX (Fracture Risk Assessment) tool developed under the aegis of the World Health Organization and the Garvan Fracture Risk Calculator are commonly used to estimate the patient's fracture risk. Both have advantages and limitations. It must be emphasized, however, that treatment decisions are clinical ones.

Fracture risk reduction is the main goal of treating osteoporosis, a condition which, in the absence of fragility fractures, is diagnosed by bone densitometry. Bone density, however, although an important factor predicting fracture risk, is not the only one and several other factors modulate the fracture risk such as the patient's age, body mass index, family history, cigarette smoking, medications and the risk of falling: most fractures are preceded by falls. When developing a treatment strategy it is therefore important to take into consideration other factors apart from bone density. Several algorithms and instruments are available for this purpose. The FRAX (Fracture Risk Assessment) tool developed under the aegis of the World Health Organization and the Garvan Fracture Risk Calculator are commonly used to estimate the patient's fracture risk. Both have advantages and limitations. It must be emphasized, however, that treatment decisions are clinical ones.

There is a need to identify patients with osteopenia who are at high risk of sustaining fractures and who would benefit from treatment, since many patients with osteopenia do not sustain fractures, in 2008, the WHO unveiled the fracture risk-assessment-tool (FRAX®), which calculates the 10-year probability of a patient sustaining a fracture. It is available on the internet free of charge, and represents a major step forward since it takes into account a number of risk factors and allows clinicians to focus on those patients at high risk of sustaining fractures, in whom the benefits of treating a silent disease outweigh the potential adverse effects and cost. In the USA, the National Osteoporosis Foundation has suggested a fracture threshold to recommend treatment. In this article, the various risk factors included in the FRAX tool are briefly reviewed, and the advantages, potential limitations and possible future developments are discussed.

A osteoporose é uma doença que afeta o tecido ósseo sendo caracterizada principalmente pela diminuição da massa óssea e pela deterioração da arquitetura do osso. O método atualmente utilizado no diagnóstico da osteoporose é a densitometria óssea (DEXA -Dual Energy X-ray Absorptiometry), que utiliza radiação ionizante. Vários estudos têm sido publicados discutindo o uso de técnicas complementares ou alternativas à densitometria óssea. Uma dessas técnicas é a ultrasonometria, que é baseada na análise da propagação do ultra-som para identificar a qualidade do tecido ósseo. O objetivo desse trabalho é contribuir com o acréscimo de dados para a avaliação da possibilidade de uso dessa técnica como alternativa à técnica da densitometria óssea. Foi realizado um estudo de correlação entre medidas experimentais em ossos trabeculares de calcâneos humanos obtidas com o equipamento de ultrasonometria óssea SONOST-2000 (Vicmed/OsteoSys-MedisonÒ) e medidas de ensaio mecânico de compressão. A microscopia eletrônica de varredura foi utilizada como um teste complementar para identificar as modificações na microarquitetura das amostras de ossos humanos sadios e osteopênicos. Os resultados indicam que o BQI (Bone Quality Index – Índice de Qualidade Óssea) pode ser usado como um método indireto de averiguação das importantes propriedades na determinação do risco de fratura, como por exemplo, a tensão máxima suportada pelo material. / Osteoporosis is a disease that affects bone tissue and is characterized by a decrease in its mass and deterioration of its architeture. The current method used in osteoporosis diagnostic is bone densitometry (DEXA- Dual Energy X-ray Absorption), which utilizes ionizing radiation. Various studies have been published discussing alternatives or complimentary techniques to bone densitometry. One of these techniques is quantitative untrasound (QUS), which is based on the analysis of ultrasound spread through bone tissue to assess its quality. The objective of this work is to add more data to the discussion of this technique as an alternative to bone densitometry. Correlation studies between data from experiments in trabecular bones from the calcaneus of human cadavers have been performed using the quantitative ultrasound equipment SONOST-2000 (Vicmed/OsteoSys-Medison) and mechanical compression essays. Scanning Electron Microscopy was also used as an aid to identify modifications in the samples microarchiteture from health and osteopenic tissue. The results indicate that BQI (Bone Quality Index ) can be used as indirect method to obtain important parameters used in the assessment of fracture risk, such as the maximum load supported by the material.

A osteoporose é uma doença que afeta o tecido ósseo sendo caracterizada principalmente pela diminuição da massa óssea e pela deterioração da arquitetura do osso. O método atualmente utilizado no diagnóstico da osteoporose é a densitometria óssea (DEXA -Dual Energy X-ray Absorptiometry), que utiliza radiação ionizante. Vários estudos têm sido publicados discutindo o uso de técnicas complementares ou alternativas à densitometria óssea. Uma dessas técnicas é a ultrasonometria, que é baseada na análise da propagação do ultra-som para identificar a qualidade do tecido ósseo. O objetivo desse trabalho é contribuir com o acréscimo de dados para a avaliação da possibilidade de uso dessa técnica como alternativa à técnica da densitometria óssea. Foi realizado um estudo de correlação entre medidas experimentais em ossos trabeculares de calcâneos humanos obtidas com o equipamento de ultrasonometria óssea SONOST-2000 (Vicmed/OsteoSys-MedisonÒ) e medidas de ensaio mecânico de compressão. A microscopia eletrônica de varredura foi utilizada como um teste complementar para identificar as modificações na microarquitetura das amostras de ossos humanos sadios e osteopênicos. Os resultados indicam que o BQI (Bone Quality Index – Índice de Qualidade Óssea) pode ser usado como um método indireto de averiguação das importantes propriedades na determinação do risco de fratura, como por exemplo, a tensão máxima suportada pelo material. / Osteoporosis is a disease that affects bone tissue and is characterized by a decrease in its mass and deterioration of its architeture. The current method used in osteoporosis diagnostic is bone densitometry (DEXA- Dual Energy X-ray Absorption), which utilizes ionizing radiation. Various studies have been published discussing alternatives or complimentary techniques to bone densitometry. One of these techniques is quantitative untrasound (QUS), which is based on the analysis of ultrasound spread through bone tissue to assess its quality. The objective of this work is to add more data to the discussion of this technique as an alternative to bone densitometry. Correlation studies between data from experiments in trabecular bones from the calcaneus of human cadavers have been performed using the quantitative ultrasound equipment SONOST-2000 (Vicmed/OsteoSys-Medison) and mechanical compression essays. Scanning Electron Microscopy was also used as an aid to identify modifications in the samples microarchiteture from health and osteopenic tissue. The results indicate that BQI (Bone Quality Index ) can be used as indirect method to obtain important parameters used in the assessment of fracture risk, such as the maximum load supported by the material.