دانلود رایگان مقاله نشانگرهای زیستی مواد جدید برای خطر شکستگی

Abstract

Osteoporosis is a prevalent bone condition, characterised by low bone mass and increased fracture risk. Currently, the gold standard for identifying osteoporosis and increased fracture risk is through quantification of bone mineral density (BMD) using dual energy X-ray absorption (DEXA). However, the risk of osteoporotic fracture is determined collectively by bone mass, architecture and physicochemistry of the mineral composite building blocks. Thus DEXA scans alone inevitably fail to fully discriminate individuals who will suffer a fragility fracture. This study examines trabecular bone at both ultrastructure and microarchitectural levels to provide a detailed material view of bone, and therefore provides a more comprehensive explanation of osteoporotic fracture risk. Physicochemical characterisation obtained through X-ray diffraction and infrared analysis indicated significant differences in apatite crystal chemistry and nanostructure between fracture and non-fracture groups. Further, this study, through considering the potential correlations between the chemical biomarkers and microarchitectural properties of trabecular bone, has investigated the relationship between bone mechanical properties (e.g. fragility) and physicochemical material features.

8. Conclusion

The principal aim of this study was to investigate bone ‘quality’ in terms of mineral chemistry and organic content of fractured and nonfractured human material. Age related changes for the non-fracture material were also investigated. The relationship between the bone mineral chemical characteristics and the microarchitecture parameters was also examined. As shown through statistical analysis, the coherence length (〈00ℓ〉), ‘a’ axis lattice parameters and carbonate to phosphate ratio values (when age matched) were different between fracture and non-fracture material from female donors. The study has also shown an increase in crystallite size and a decrease in lattice disorder ([0k0]) as well as an increase in the amount of phosphate and/or a decrease in collagen occur with age for non-fracture material. It is proposed the data reported here suggests osteoporosis may not simply be an accelerated aging process when considering mineral chemistry and organic content, but there are fundamental chemical differences between fracture and non-fracture material not found with age. It is interesting to speculate that there may be a relationship between the mineral properties of bone at the ultrastructure level and the microarchitectural properties of trabecular bone.