The main aim of the work was to assess the value of selected structural parameters in description of strength of bone. In our study we focused on volume of layers Baricitinib molecular weight and fractal dimension of layers, BMD and their correlation with bone strength. We also wanted to find out which parameter would be better for description of bone strength.2. Material and Methods2.1. SpecimenWe tested trabecular bone samples. Samples were collected from 42 human femoral heads, the mean age of the patients was 73yr (range 50�C91). These specimens were obtained during hip arthroplasty. The study was approved by the Local Ethic Committee. First, slices were cut out from the base of the head at 8,5mm thickness, perpendicular to the axis of the neck of the bone (Figure 1(a)).

Then, from the central region of the slices (Figure 1(b)), the samples were cut out in the shape of a cylinder, 10mm diameter and 8,5mm height (Figure 1(c)).Figure 1Method of obtaining sample: (a) cutting of slice; (b) cutting of sample; (c) final shape of sample.2.2. MicroCT TechniqueMicroCT investigation of cylindrical samples was done on microCT scanner (MicroCT 80 scanner, Scanco-Medical AG, Switzerland) with resolutions of 36 microns and with basic parameters: 70kV, 114��A, 500 projections/180��, and 300ms integration time. Thus we obtained around 230 scans for each sample. On the base of these images, the representative geometry of the sample was done using a bone reconstruction algorithm called ��hexahedron method�� [20].In this algorithm, single layers of a model were created by comparing images of two neighboring scans.

When on the same coordinate in both scans the color of pixels represented bone, voxels of bone between the scans were created. On the contrary when none or only one pixel was colored, it was omitted.A cube was created, the so-called voxel with its base, in shape of square of side of one pixel long. Its height equals the distance between neighboring layers (cube of dimensions of 36 �� 36 �� 36 microns). Having checked all pairs of pixels in two specific scans the next pair of images were recorded and the whole procedure was repeated and another layer of cubes created.2.3. Volume CalculationOn the basis of geometry prepared in this way, the bone volume parameters of the sample structure were calculated for every layer assigned as local volumetric parameter. It was performed by calculating number of bone voxels of known dimensions. For each sample volume of single layer (V) was calculated and, respectively, mean volume (Vm) for the whole sample. Then, the standard deviation (SD) for Vm (SDVm) and relative standard Entinostat deviation (RSD) for Vm (RSDVm) were calculated.2.4. Fractal DimensionTo assess the complexity of the bone structure we applied fractal dimension.