Determinants of bone damage: An ex-vivo study on porcine vertebrae

Bone\u2019s resistance to fracture depends on several factors, such as bone mass, microarchitecture, and tissue material properties. The clinical assessment of bone strength is generally performed by Dual-X Ray Photon Absorptiometry (DXA), measuring bone mineral density (BMD) and trabecular bone score (TBS). Although it is considered the major predictor of bone strength, BMD only accounts for about 70% of fragility fractures, while the remaining 30% could be described by bone \u201cquality\u201d impairment parameters, mainly related to tissue microarchitecture. The assessment of bone microarchitecture generally requires more invasive techniques, which are not applicable in routine clinical practice, or X-Ray based imaging techniques, requiring a longer post-processing. Another important aspect is the presence of local damage in the bony tissue that may also affect the prediction of bone strength and fracture risk. To provide a more comprehensive analysis of bone quality and quantity, and to assess the effect of damage, here we adopt a framework that includes clinical, morphological, and mechanical analyses, carried out by means of DXA, \u3bcCT and mechanical compressive testing, respectively. This study has been carried out on trabecular bones, taken from porcine trabecular vertebrae, for the similarity with human lumbar spine. This study confirms that no single method can provide a complete characterization of bone tissue, and the combination of complementary characterization techniques is required for an accurate and exhaustive description of bone status. BMD and TBS have shown to be complementary parameters to assess bone strength, the former assessing the bone quantity and resistance to damage, and the latter the bone quality and the presence of damage accumulation without being able to predict the risk of fracture

Increased serum OPG in atrophic nonunion shaft fractures

Background Bone repair alteration is hypothesized for nonunion fracture pathogenesis. Since it is involved in osteoclast regulation, the RANK/RANKL/OPG system (receptor activator of nuclear factor kB/its ligand/osteoprotegerin) may play a role. Materials and methods Serum OPG, free RANKL, bone alkaline phosphatase (BAP), osteocalcin (OC), and urinary deoxypyridinoline (DPD) were determined in 16 male patients (20\u201339 years) with long bone atrophic nonunion fractures. Serum markers were also measured in 18 agematched male controls who healed from the same type of fractures within six months, and in 14 age-matched male controls who were healing from the same fractures one month after injury. One-way ANOVA and Bonferroni\u2019s test were used for statistical analysis. Results Only OPG was significantly higher (0.56 sd 0.11 ng/ml) in the patients compared to healed (0.26 sd 0.04 ng/ml; P\0.001) and healing (0.29 sd 0.09 ng/ml; P\0.001) controls. The patients\u2019 DPD levels were normal. No correlations were found between bone markers and the characteristics of the subjects in all groups. Conclusions A normal steady state of bone metabolism seems to be present in patients with atrophic nonunion fractures, despite the high serum OPG. The reason for the inability of the patients\u2019 OPG to inhibit osteoclastic activity is unknown. Osteoblast activity also appears normal, so another cellular source of OPG can be hypothesized

Fifth European Dirofilaria and Angiostrongylus Days (FiEDAD) 2016

Peer reviewe

DXA-Based Bone Strain Index: A New Tool to Evaluate Bone Quality in Primary Hyperparathyroidism

Primary hyperparathyroidism (PHPT) is associated with impaired bone quality and increased fracture risk. Reliable tools for the evaluation of bone quality parameters are not yet clinically available. Bone Strain Index (BSI) is a new metric for bone strength based on Finite Element Analysis from lumbar spine and femoral neck dual X-ray absorptiometry images

Semantic map showing the relations between the investigated anagraphic, antropometric, densitometric, biochemical and clinical parameters.

<p>Semantic map showing the relations between the investigated anagraphic, antropometric, densitometric, biochemical and clinical parameters.</p

Characteristics of patients.

<p>Characteristics of patients.</p