Trabecular Bone Research Papers - Academia.edu (original) (raw)

Developing a novel technique for the efficient, noninvasive clinical evaluation of bone microarchitecture remains both crucial and challenging. The trabecular bone score (TBS) is a new gray-level texture measurement that is applicable to... more

Developing a novel technique for the efficient, noninvasive clinical evaluation of bone microarchitecture remains both crucial and challenging. The trabecular bone score (TBS) is a new gray-level texture measurement that is applicable to dual-energy X-ray absorptiometry (DXA) images. Significant correlations between TBS and standard 3-dimensional (3D) parameters of bone microarchitecture have been obtained using a numerical simulation approach. The main objective of this study was to empirically evaluate such correlations in anteroposterior spine DXA images. Thirty dried human cadaver vertebrae were evaluated. Micro-computed tomography acquisitions of the bone pieces were obtained at an isotropic resolution of 93μm. Standard parameters of bone microarchitecture were evaluated in a defined region within the vertebral body, excluding cortical bone. The bone pieces were measured on a Prodigy DXA system (GE Medical-Lunar, Madison, WI), using a custom-made positioning device and experimental setup. Significant correlations were detected between TBS and 3D parameters of bone microarchitecture, mostly independent of any correlation between TBS and bone mineral density (BMD). The greatest correlation was between TBS and connectivity density, with TBS explaining roughly 67.2% of the variance. Based on multivariate linear regression modeling, we have established a model to allow for the interpretation of the relationship between TBS and 3D bone microarchitecture parameters. This model indicates that TBS adds greater value and power of differentiation between samples with similar BMDs but different bone microarchitectures. It has been shown that it is possible to estimate bone microarchitecture status derived from DXA imaging using TBS.

Initial strength of quadrupled hamstring tendon grafts fixed with titanium interference screws was assessed in 30 pairs of porcine tibiae. Bone tunnels were drilled with either compaction drilling (stepped routers) or conventional... more

Initial strength of quadrupled hamstring tendon grafts fixed with titanium interference screws was assessed in 30 pairs of porcine tibiae. Bone tunnels were drilled with either compaction drilling (stepped routers) or conventional extraction drilling (cannulated drill bits). Fifteen pairs of specimens were subjected to a single-cycle load-to-failure test, while the rest underwent a cyclic-loading test to further assess the quality of the fixation. No significant difference between the two drilling techniques was found with regard to yield load, displacement at yield load, stiffness, or mode of failure. Porcine trabecular bone mineral density was determined using peripheral quantitative computed tomography and compared with that of young women and men at a site corresponding to that of the tibial bone drill hole of an anterior cruciate ligament reconstruction. There was a significant difference between the two species (210 +/- 45 mg/cm(3) in porcine tibial bone versus 129 +/- 30 mg/c...

The ability of Minkowski Functionals to characterize local structure in different biological tissue types has been demonstrated in a variety of medical image processing tasks. We introduce anisotropic Minkowski Functionals (AMFs) as a... more

The ability of Minkowski Functionals to characterize local structure in different biological tissue types has been demonstrated in a variety of medical image processing tasks. We introduce anisotropic Minkowski Functionals (AMFs) as a novel variant that captures the inherent anisotropy of the underlying gray-level structures. To quantify the anisotropy characterized by our approach, we further introduce a method to compute a quantitative measure motivated by a technique utilized in MR diffusion tensor imaging, namely fractional anisotropy. We showcase the applicability of our method in the research context of characterizing the local structure properties of trabecular bone micro-architecture in the proximal femur as visualized on multi-detector CT. To this end, AMFs were computed locally for each pixel of ROIs extracted from the head, neck and trochanter regions. Fractional anisotropy was then used to quantify the local anisotropy of the trabecular structures found in these ROIs and to compare its distribution in different anatomical regions. Our results suggest a significantly greater concentration of anisotropic trabecular structures in the head and neck regions when compared to the trochanter region (p < 10-4). We also evaluated the ability of such AMFs to predict bone strength in the femoral head of proximal femur specimens obtained from 50 donors. Our results suggest that such AMFs, when used in conjunction with multi-regression models, can outperform more conventional features such as BMD in predicting failure load. We conclude that such anisotropic Minkowski Functionals can capture valuable information regarding directional attributes of local structure, which may be useful in a wide scope of biomedical imaging applications.

Transgenic mice carrying an internally deleted human type II collagen gene (COL2A1) were used to study bone growth and development. This mutation has previously been shown to disturb the development of collagen fibrils in articular... more

Transgenic mice carrying an internally deleted human type II collagen gene (COL2A1) were used to study bone growth and development. This mutation has previously been shown to disturb the development of collagen fibrils in articular cartilage, causing chondrodysplasia and osteoarthritis. Type II collagen expression in bones was investigated with immunohistochemistry. The development and mineralization of the skeleton and anthropometric measurements on bones were evaluated using X-rays and dynamic histomorphometry. Type II collagen was expressed in the cartilage of developing bones. The bones of transgenic mice were smaller compared with the controls. The bone mass remained almost unchanged in transgenic mice after 1 month of age, leading to differences of 47% in trabecular bone volume (P = 0.012) and 40% in trabecular thickness (P P R = 0.71, P R = 0.27, P

Objectives: Internal bone structure, both cortical and trabecular bone, remodels in response to loading and may provide important information regarding behavior. The foot is well suited to analysis of internal bone structure because it... more

Objectives: Internal bone structure, both cortical and trabecular bone, remodels in response to loading and may provide important information regarding behavior. The foot is well suited to analysis of internal bone structure because it experiences the initial substrate reaction forces, due to its proximity to the substrate. Moreover, as humans and apes differ in loading of the foot, this region is relevant to questions concerning arboreal locomotion and bipedality in the hominoid fossil record. Materials and methods: We apply a whole-bone/epiphysis approach to analyze trabecular and cortical bone in the distal tibia and talus of Pan troglodytes and Homo sapiens. We quantify bone volume fraction (BV/TV), degree of anisotropy (DA), trabecular thickness (Tb.Th), bone surface to volume ratio (BS/BV), and cortical thickness and investigate the distribution of BV/TV and cortical thickness throughout the bone/epiphysis. Results: We find that Pan has a greater BV/TV, a lower BS/BV and thicker cortices than Homo in both the talus and distal tibia. The trabecular structure of the talus is more divergent than the tibia, having thicker, less uniformly aligned trabeculae in Pan compared to Homo. Differences in dorsi-flexion at the talocrural joint and in degree of mobility at the talonavicular joint are reflected in the distribution of cortical and trabecular bone.

Biological systems outperform classical engineering in material optimization and structural efficiency, where redundancy and differentiation features give the hierarchical natural systems the ability to withstand various changes and... more

Biological systems outperform classical engineering in material optimization and structural efficiency, where redundancy and differentiation features give the hierarchical natural systems the ability to withstand various changes and stresses. This research paper aims to study the difference between the engineering principles of biological systems and classical architectural engineering systems. It studies how to apply nature principles on architectural projects in order to provide more rigid structures, this is done through studying some architectural and structural projects examples that took biological forms principles as its main inspiration.

Casein phosphopeptides (CPPs), originating by in vitro and/or in vivo casein digestion, are characterized by the ability to complex and solubilize calcium ions preventing their precipitation. Previous works demonstrated that CPPs improve... more

Casein phosphopeptides (CPPs), originating by in vitro and/or in vivo casein digestion, are characterized by the ability to complex and solubilize calcium ions preventing their precipitation. Previous works demonstrated that CPPs improve calcium uptake by human differentiated intestinal tumor cell lines, are able to re-mineralize carious lesions in a dental enamel, and, as components of a diet, affect bone weight and calcium content in rats. The aim of the present study was to evaluate if CPPs can directly modulate bone cells activity and mineralization. Primary human osteoblast-like cells were established in culture from trabecular bone samples obtained from waste materials during orthopedic surgery. Commercial mixtures of bovine casein phosphopeptides were used. The CPP dependent intracellular calcium rises were monitored at the single cell level through fura2-fluorescence assays. Results show that CPPs: (i) stimulate calcium uptake by primary human osteoblast-like cells; (ii) increase the expression and activity of alkaline phosphatase, a marker of human osteoblast differentiation; (iii) affect the cell proliferation rate and the apoptotic level; (iv) enhance nodule formation by human SaOS-2. Taken together these results confirm the possibility that CPPs play a role as modulator of bone cell activity, probably sustained by their ability as calcium carriers. Although the exact mechanism by which CPPs act remains not completely clarified, they can be considered as potential anabolic factors for bone tissue engineering.

Introduction: Juvenile ossifying fibromas are uncommon benign tumors. Their aggressiveness added to their high tendency to recur, provoke real diagnostic and therapeutic challenges for the dental practitioner and make a postoperative... more

Introduction: Juvenile ossifying fibromas are uncommon benign tumors. Their aggressiveness added to their high tendency to recur, provoke real diagnostic and therapeutic challenges for the dental practitioner and make a postoperative follow-up over the years indispensable. Case report: In this report, we present a case of a seven-year-old girl presented with a swelling in the face at the upper right maxillary region. After clinical, radiological, and histopathological examinations the diagnosis of trabecular juvenile ossifying fibroma was made. The lesion was surgically excised and followed up for two years with no evidence of recurrence.

In this work we investigated the consequences of irradiation in the femur of rats to a radiation dose of 5 Gy. Three different sites in femur specimens were imaged using synchrotron radiation computed microtomography to assess trabecular... more

In this work we investigated the consequences of irradiation in the femur of rats to a radiation dose of 5 Gy. Three different sites in femur specimens were imaged using synchrotron radiation computed microtomography to assess trabecular bone microarchitecture: femur head, distal metaphysis and distal epiphysis. Histomorphometric quantification was extracted directly from the 3D tomographic images using synchrontron radiation. The

The aim of the study was to evaluate the effect of two lossy image compression methods on fractal dimension (FD) calculation. Ten periapical images of the posterior teeth with no restorations or previous root canal therapy were obtained... more

The aim of the study was to evaluate the effect of two lossy image compression methods on fractal dimension (FD) calculation. Ten periapical images of the posterior teeth with no restorations or previous root canal therapy were obtained using storage phosphor plates and were saved in TIF format. Then, all images were compressed with lossy JPEG and JPEG2000 compression methods at five compression levels, i.e., 90, 70, 50, 30, and 10. Compressed file sizes from all images and compression ratios were calculated. On each image, two regions of interest (ROIs) containing healthy trabecular bone in the posterior periapical area were selected. The FD of each ROI on the original and compressed images was calculated using differential box counting method. Both image compression and analysis were performed by a public domain software. Altogether, the FD of 220 ROIs was calculated. FDs were compared using ANOVA and Dunnett tests. The FD decreased gradually with compression level. A statistically significant decrease of the FD values was found for JPEG 10, JPEG2000 10, and JPEG2000 30 compression levels (p < 0.05). At comparable file sizes, the JPEG induced a smaller FD difference. In conclusion, lossy compressed images with appropriate compression level may be used for FD calculation.